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Sample records for california current ecosystem

  1. Mesopelagic fish biomass in the southern California current ecosystem

    NASA Astrophysics Data System (ADS)

    Davison, Peter; Lara-Lopez, Ana; Anthony Koslow, J.

    2015-02-01

    Mesopelagic fishes are the most common vertebrates on Earth, forming an important link between lower trophic levels and higher predators, and also between surface production and the deep sea. The biomass of these fishes is a key parameter for ecological modeling of oceanic ecosystems, but it is poorly known. The two most common methods to estimate the biomass of these fishes, acoustic and trawl surveys, are both sensitive to the ability of fishes to avoid nets. We show that size-dependent changes in trawl capture efficiency can affect acoustic estimates of biomass estimates 5-fold. We used both acoustic and trawl-based methods (informed by morphological data and acoustic modeling of individual backscattering) to estimate the biomass of mesopelagic fishes of southern California to be 25-37 g m-2 of ocean surface, a comparable density to that of inshore epipelagic zooplanktivorous fishes. Our results indicate that mesopelagic fishes are likely to play a major role in regional food webs.

  2. Impact of assimilating physical oceanographic data on modeled ecosystem dynamics in the California Current System

    NASA Astrophysics Data System (ADS)

    Raghukumar, Kaustubha; Edwards, Christopher A.; Goebel, Nicole L.; Broquet, Gregoire; Veneziani, Milena; Moore, Andrew M.; Zehr, Jon P.

    2015-11-01

    A method to model ocean ecosystems using data-constrained physical circulation estimates is investigated. Physical oceanographic data is assimilated into a Regional Ocean Modeling System implementation of the California Current System using an incremental 4-Dimensional Variational method. The resulting state estimate drives a complex, self-assembling ocean ecosystem model for the year 2003, and results are evaluated against SeaWiFS surface and CalCOFI subsurface observations and with ecosystem model output driven by an unconstrained physical model. While physical data assimilation improves correlation with observations, this method also drives elevated levels of phytoplankton standing stock, leading to a large bias particularly in regions of low mean concentration. We identify two causes for this increase: biological rectification of fluctuating vertical nutrient transport due to gravity wave generation at assimilation cycle initialization and increased nutrient variance on density surfaces. We investigate one and propose other possible remedies for these deleterious side-effects of this data assimilation method.

  3. Humpback whale diets respond to variance in ocean climate and ecosystem conditions in the California Current.

    PubMed

    Fleming, Alyson H; Clark, Casey T; Calambokidis, John; Barlow, Jay

    2016-03-01

    Large, migratory predators are often cited as sentinel species for ecosystem processes and climate-related changes, but their utility as indicators is dependent upon an understanding of their response to environmental variability. Documentation of the links between climate variability, ecosystem change and predator dynamics is absent for most top predators. Identifying species that may be useful indicators and elucidating these mechanistic links provides insight into current ecological dynamics and may inform predictions of future ecosystem responses to climatic change. We examine humpback whale response to environmental variability through stable isotope analysis of diet over a dynamic 20-year period (1993-2012) in the California Current System (CCS). Humpback whale diets captured two major shifts in oceanographic and ecological conditions in the CCS. Isotopic signatures reflect a diet dominated by krill during periods characterized by positive phases of the North Pacific Gyre Oscillation (NPGO), cool sea surface temperature (SST), strong upwelling and high krill biomass. In contrast, humpback whale diets are dominated by schooling fish when the NPGO is negative, SST is warmer, seasonal upwelling is delayed and anchovy and sardine populations display increased biomass and range expansion. These findings demonstrate that humpback whales trophically respond to ecosystem shifts, and as a result, their foraging behavior is a synoptic indicator of oceanographic and ecological conditions across the CCS. Multi-decadal examination of these sentinel species thus provides insight into biological consequences of interannual climate fluctuations, fundamental to advancing ecosystem predictions related to global climate change. PMID:26599719

  4. Introduction to CCE-LTER: Responses of the California Current Ecosystem to climate forcing

    NASA Astrophysics Data System (ADS)

    Goericke, R.; Ohman, M. D.

    2015-02-01

    The California Current Ecosystem Long Term Ecological Research (CCE-LTER) site has been in existence since 2004. One of its primary objectives is to understand the response of the southern California Current ecosystem to climate forcing. The CCE-LTER site cooperates with the California Cooperative Oceanic Fisheries Investigations (CalCOFI) program and complements CalCOFI's work through more extensive observations, process studies, and a modeling program. This special issue is focused on the long-term observations made by the CCE-LTER and CalCOFI programs, describing and understanding long-term changes in the physical, chemical, and biotic environment in the region. The papers in this issue highlight the climatological conditions during recent years and employ modeling to diagnose the principal forcing of meridional currents and eddy transport, both of which affect biotic responses. Changes in source waters in the region, and altered flushing of the Santa Barbara Basin, are considered. Temporal variations in inherent optical properties and in higher trophic levels, including seabirds and marine mammals, are presented. Key methodological developments presented include the incorporation of subsurface phytoplankton and light distributions in order to improve remotely sensed measures of primary production, and the validation of multi-frequency acoustic estimates of mesopelagic fish biomass. Results also highlight significant spatial differences across the CCE-LTER region, including cross-shore trends in microbial assemblages, and glider-resolved frontal features and zones of mixing associated with abrupt topography. Alterations to the spatial structure of the pelagic ecosystem must also be considered when evaluating future climate-related changes.

  5. Exploring local adaptation and the ocean acidification seascape - studies in the California Current Large Marine Ecosystem

    NASA Astrophysics Data System (ADS)

    Hofmann, G. E.; Evans, T. G.; Kelly, M. W.; Padilla-Gamio, J. L.; Blanchette, C. A.; Washburn, L.; Chan, F.; McManus, M. A.; Menge, B. A.; Gaylord, B.; Hill, T. M.; Sanford, E.; LaVigne, M.; Rose, J. M.; Kapsenberg, L.; Dutton, J. M.

    2014-02-01

    The California Current Large Marine Ecosystem (CCLME), a temperate marine region dominated by episodic upwelling, is predicted to experience rapid environmental change in the future due to ocean acidification. The aragonite saturation state within the California Current System is predicted to decrease in the future with near-permanent undersaturation conditions expected by the year 2050. Thus, the CCLME is a critical region to study due to the rapid rate of environmental change that resident organisms will experience and because of the economic and societal value of this coastal region. Recent efforts by a research consortium - the Ocean Margin Ecosystems Group for Acidification Studies (OMEGAS) - has begun to characterize a portion of the CCLME; both describing the spatial mosaic of pH in coastal waters and examining the responses of key calcification-dependent benthic marine organisms to natural variation in pH and to changes in carbonate chemistry that are expected in the coming decades. In this review, we present the OMEGAS strategy of co-locating sensors and oceanographic observations with biological studies on benthic marine invertebrates, specifically measurements of functional traits such as calcification-related processes and genetic variation in populations that are locally adapted to conditions in a particular region of the coast. Highlighted in this contribution are (1) the OMEGAS sensor network that spans the west coast of the US from central Oregon to southern California, (2) initial findings of the carbonate chemistry amongst the OMEGAS study sites, and (3) an overview of the biological data that describes the acclimatization and the adaptation capacity of key benthic marine invertebrates within the CCLME.

  6. Exploring local adaptation and the ocean acidification seascape - studies in the California Current Large Marine Ecosystem

    NASA Astrophysics Data System (ADS)

    Hofmann, G. E.; Evans, T. G.; Kelly, M. W.; Padilla-Gamio, J. L.; Blanchette, C. A.; Washburn, L.; Chan, F.; McManus, M. A.; Menge, B. A.; Gaylord, B.; Hill, T. M.; Sanford, E.; LaVigne, M.; Rose, J. M.; Kapsenberg, L.; Dutton, J. M.

    2013-07-01

    The California Current Large Marine Ecosystem (CCLME), a temperate marine region dominated by episodic upwelling, is predicted to experience rapid environmental change in the future due to ocean acidification. Aragonite saturation state within the California Current System is predicted to decrease in the future, with near-permanent undersaturation conditions expected by the year 2050. Thus, the CCLME is a critical region to study due to the rapid rate of environmental change that resident organisms will experience and because of the economic and societal value of this coastal region. Recent efforts by a research consortium - the Ocean Margin Ecosystems Group for Acidification Studies (OMEGAS) - has begun to characterize a portion of the CCLME; both describing the mosaic of pH in coastal waters and examining the responses of key calcification-dependent benthic marine organisms to natural variation in pH and to changes in carbonate chemistry that are expected in the coming decades. In this review, we present the OMEGAS strategy of co-locating sensors and oceanographic observations with biological studies on benthic marine invertebrates, specifically measurements of functional traits such as calcification-related processes and genetic variation in populations that are locally adapted to conditions in a particular region of the coast. Highlighted in this contribution are (1) the OMEGAS sensor network that spans the west coast of the US from central Oregon to southern California, (2) initial findings of the carbonate chemistry amongst the OMEGAS study sites, (3) an overview of the biological data that describes the acclimatization and the adaptation capacity of key benthic marine invertebrates within the CCLME.

  7. Screening California Current fishery management scenarios using the Atlantis end-to-end ecosystem model

    NASA Astrophysics Data System (ADS)

    Kaplan, Isaac C.; Horne, Peter J.; Levin, Phillip S.

    2012-09-01

    End-to-end marine ecosystem models link climate and oceanography to the food web and human activities. These models can be used as forecasting tools, to strategically evaluate management options and to support ecosystem-based management. Here we report the results of such forecasts in the California Current, using an Atlantis end-to-end model. We worked collaboratively with fishery managers at NOAAs regional offices and staff at the National Marine Sanctuaries (NMS) to explore the impact of fishery policies on management objectives at different spatial scales, from single Marine Sanctuaries to the entire Northern California Current. In addition to examining Status Quo management, we explored the consequences of several gear switching and spatial management scenarios. Of the scenarios that involved large scale management changes, no single scenario maximized all performance metrics. Any policy choice would involve trade-offs between stakeholder groups and policy goals. For example, a coast-wide 25% gear shift from trawl to pot or longline appeared to be one possible compromise between an increase in spatial management (which sacrificed revenue) and scenarios such as the one consolidating bottom impacts to deeper areas (which did not perform substantially differently from Status Quo). Judged on a coast-wide scale, most of the scenarios that involved minor or local management changes (e.g. within Monterey Bay NMS only) yielded results similar to Status Quo. When impacts did occur in these cases, they often involved local interactions that were difficult to predict a priori based solely on fishing patterns. However, judged on the local scale, deviation from Status Quo did emerge, particularly for metrics related to stationary species or variables (i.e. habitat and local metrics of landed value or bycatch). We also found that isolated management actions within Monterey Bay NMS would cause local fishers to pay a cost for conservation, in terms of reductions in landed value. However, this cost was minimal when local conservation actions were part of a concerted coast-wide plan. The simulations demonstrate the utility of using the Atlantis end-to-end ecosystem model within NOAAs Integrated Ecosystem Assessment, by illustrating an end-to-end modeling tool that allows consideration of multiple management alternatives that are relevant to numerous state, federal and private interests.

  8. Shearwaters as ecosystem indicators: Towards fishery-independent metrics of fish abundance in the California Current

    NASA Astrophysics Data System (ADS)

    Lyday, Shannon E.; Ballance, Lisa T.; Field, David B.; David Hyrenbach, K.

    2015-06-01

    Shearwaters are ideal for monitoring ocean conditions in the California Current because these predators are abundant, conspicuous, and responsive to oceanographic variability. Herein we evaluated black-vented (Puffinus opisthomelas), Buller's (P. bulleri), flesh-footed (P. carneipes), pink-footed (P. creatopus), short-tailed (P. tenuirostris), and sooty (P. griseus) shearwaters as fishery-independent indicators of predatory or prey fish availability. We analyzed four years (1996, 2001, 2005, 2008) of monthly (August-November) National Oceanic and Atmospheric Administration seabird surveys, and United States Geological Survey Pacific Coast Fisheries Database catch, from the California coast to 200 nm offshore. An ordination of shearwater abundance and fish catch revealed that the shearwaters and 11 fish/squid species were significantly correlated with one or more of three principal components, which explained 86% of the variation and revealed distinct species assemblages. We evaluated multiple linear regression models for 19 fisheries using five shearwater metrics: density, aggregation, and behavior (traveling, stationary, feeding), three oceanographic indices, and latitude. Eight of these models had a shearwater metric as the primary predictor. In particular, feeding black-vented shearwater abundance explained 75% of dolphinfish (Coryphaena hippurus) longline catch. This research illustrates the utility of shearwaters as ecosystem indicators, with direct application for predicting fishery catch of commercial importance.

  9. Delayed upwelling alters nearshore coastal ocean ecosystems in the northern California current

    PubMed Central

    Barth, John A.; Menge, Bruce A.; Lubchenco, Jane; Chan, Francis; Bane, John M.; Kirincich, Anthony R.; McManus, Margaret A.; Nielsen, Karina J.; Pierce, Stephen D.; Washburn, Libe

    2007-01-01

    Wind-driven coastal ocean upwelling supplies nutrients to the euphotic zone near the coast. Nutrients fuel the growth of phytoplankton, the base of a very productive coastal marine ecosystem [Pauly D, Christensen V (1995) Nature 374:255257]. Because nutrient supply and phytoplankton biomass in shelf waters are highly sensitive to variation in upwelling-driven circulation, shifts in the timing and strength of upwelling may alter basic nutrient and carbon fluxes through marine food webs. We show how a 1-month delay in the 2005 spring transition to upwelling-favorable wind stress in the northern California Current Large Marine Ecosystem resulted in numerous anomalies: warm water, low nutrient levels, low primary productivity, and an unprecedented low recruitment of rocky intertidal organisms. The delay was associated with 20- to 40-day wind oscillations accompanying a southward shift of the jet stream. Early in the upwelling season (MayJuly) off Oregon, the cumulative upwelling-favorable wind stress was the lowest in 20 years, nearshore surface waters averaged 2C warmer than normal, surf-zone chlorophyll-a and nutrients were 50% and 30% less than normal, respectively, and densities of recruits of mussels and barnacles were reduced by 83% and 66%, respectively. Delayed early-season upwelling and stronger late-season upwelling are consistent with predictions of the influence of global warming on coastal upwelling regions. PMID:17360419

  10. Declining Abundance of Beaked Whales (Family Ziphiidae) in the California Current Large Marine Ecosystem

    PubMed Central

    Moore, Jeffrey E.; Barlow, Jay P.

    2013-01-01

    Beaked whales are among the most diverse yet least understood groups of marine mammals. A diverse set of mostly anthropogenic threats necessitates improvement in our ability to assess population status for this cryptic group. The Southwest Fisheries Science Center (NOAA) conducted six ship line-transect cetacean abundance surveys in the California Current off the contiguous western United States between 1991 and 2008. We used a Bayesian hidden-process modeling approach to estimate abundance and population trends of beaked whales using sightings data from these surveys. We also compiled records of beaked whale stranding events (3 genera, at least 8 species) on adjacent beaches from 1900 to 2012, to help assess population status of beaked whales in the northern part of the California Current. Bayesian posterior summaries for trend parameters provide strong evidence of declining beaked whale abundance in the study area. The probability of negative trend for Cuvier's beaked whale (Ziphius cavirostris) during 19912008 was 0.84, with 1991 and 2008 estimates of 10771 (CV?=?0.51) and ?7550 (CV?=?0.55), respectively. The probability of decline for Mesoplodon spp. (pooled across species) was 0.96, with 1991 and 2008 estimates of 2206 (CV?=?0.46) and 811 (CV?=?0.65). The mean posterior estimates for average rate of decline were 2.9% and 7.0% per year. There was no evidence of abundance trend for Baird's beaked whale (Berardius bairdii), for which annual abundance estimates in the survey area ranged from ?900 to 1300 (CV?1.3). Stranding data were consistent with the survey results. Causes of apparent declines are unknown. Direct impacts of fisheries (bycatch) can be ruled out, but impacts of anthropogenic sound (e.g., naval active sonar) and ecosystem change are plausible hypotheses that merit investigation. PMID:23341907

  11. Declining abundance of beaked whales (family Ziphiidae) in the California Current large marine ecosystem.

    PubMed

    Moore, Jeffrey E; Barlow, Jay P

    2013-01-01

    Beaked whales are among the most diverse yet least understood groups of marine mammals. A diverse set of mostly anthropogenic threats necessitates improvement in our ability to assess population status for this cryptic group. The Southwest Fisheries Science Center (NOAA) conducted six ship line-transect cetacean abundance surveys in the California Current off the contiguous western United States between 1991 and 2008. We used a Bayesian hidden-process modeling approach to estimate abundance and population trends of beaked whales using sightings data from these surveys. We also compiled records of beaked whale stranding events (3 genera, at least 8 species) on adjacent beaches from 1900 to 2012, to help assess population status of beaked whales in the northern part of the California Current. Bayesian posterior summaries for trend parameters provide strong evidence of declining beaked whale abundance in the study area. The probability of negative trend for Cuvier's beaked whale (Ziphius cavirostris) during 1991-2008 was 0.84, with 1991 and 2008 estimates of 10771 (CV = 0.51) and ?7550 (CV = 0.55), respectively. The probability of decline for Mesoplodon spp. (pooled across species) was 0.96, with 1991 and 2008 estimates of 2206 (CV = 0.46) and 811 (CV = 0.65). The mean posterior estimates for average rate of decline were 2.9% and 7.0% per year. There was no evidence of abundance trend for Baird's beaked whale (Berardius bairdii), for which annual abundance estimates in the survey area ranged from ?900 to 1300 (CV?1.3). Stranding data were consistent with the survey results. Causes of apparent declines are unknown. Direct impacts of fisheries (bycatch) can be ruled out, but impacts of anthropogenic sound (e.g., naval active sonar) and ecosystem change are plausible hypotheses that merit investigation. PMID:23341907

  12. Climate change and decadal shifts in the phenology of larval fishes in the California Current ecosystem.

    PubMed

    Asch, Rebecca G

    2015-07-28

    Climate change has prompted an earlier arrival of spring in numerous ecosystems. It is uncertain whether such changes are occurring in Eastern Boundary Current Upwelling ecosystems, because these regions are subject to natural decadal climate variability, and regional climate models predict seasonal delays in upwelling. To answer this question, the phenology of 43 species of larval fishes was investigated between 1951 and 2008 off southern California. Ordination of the fish community showed earlier phenological progression in more recent years. Thirty-nine percent of seasonal peaks in larval abundance occurred earlier in the year, whereas 18% were delayed. The species whose phenology became earlier were characterized by an offshore, pelagic distribution, whereas species with delayed phenology were more likely to reside in coastal, demersal habitats. Phenological changes were more closely associated with a trend toward earlier warming of surface waters rather than decadal climate cycles, such as the Pacific Decadal Oscillation and North Pacific Gyre Oscillation. Species with long-term advances and delays in phenology reacted similarly to warming at the interannual time scale as demonstrated by responses to the El Nio Southern Oscillation. The trend toward earlier spawning was correlated with changes in sea surface temperature (SST) and mesozooplankton displacement volume, but not coastal upwelling. SST and upwelling were correlated with delays in fish phenology. For species with 20th century advances in phenology, future projections indicate that current trends will continue unabated. The fate of species with delayed phenology is less clear due to differences between Intergovernmental Panel on Climate Change models in projected upwelling trends. PMID:26159416

  13. Climate change and decadal shifts in the phenology of larval fishes in the California Current ecosystem

    PubMed Central

    Asch, Rebecca G.

    2015-01-01

    Climate change has prompted an earlier arrival of spring in numerous ecosystems. It is uncertain whether such changes are occurring in Eastern Boundary Current Upwelling ecosystems, because these regions are subject to natural decadal climate variability, and regional climate models predict seasonal delays in upwelling. To answer this question, the phenology of 43 species of larval fishes was investigated between 1951 and 2008 off southern California. Ordination of the fish community showed earlier phenological progression in more recent years. Thirty-nine percent of seasonal peaks in larval abundance occurred earlier in the year, whereas 18% were delayed. The species whose phenology became earlier were characterized by an offshore, pelagic distribution, whereas species with delayed phenology were more likely to reside in coastal, demersal habitats. Phenological changes were more closely associated with a trend toward earlier warming of surface waters rather than decadal climate cycles, such as the Pacific Decadal Oscillation and North Pacific Gyre Oscillation. Species with long-term advances and delays in phenology reacted similarly to warming at the interannual time scale as demonstrated by responses to the El Niño Southern Oscillation. The trend toward earlier spawning was correlated with changes in sea surface temperature (SST) and mesozooplankton displacement volume, but not coastal upwelling. SST and upwelling were correlated with delays in fish phenology. For species with 20th century advances in phenology, future projections indicate that current trends will continue unabated. The fate of species with delayed phenology is less clear due to differences between Intergovernmental Panel on Climate Change models in projected upwelling trends. PMID:26159416

  14. Temporal and spatial patterns of microbial community biomass and composition in the Southern California Current Ecosystem

    NASA Astrophysics Data System (ADS)

    Taylor, Andrew G.; Landry, Michael R.; Selph, Karen E.; Wokuluk, John J.

    2015-02-01

    As part of the California Current Ecosystem Long Term Ecological Research (CCE-LTER) Program, samples for epifluorescence microscopy and flow cytometry (FCM) were collected at ten 'cardinal' stations on the California Cooperative Oceanic Fisheries Investigations (CalCOFI) grid during 25 quarterly cruises from 2004 to 2010 to investigate the biomass, composition and size-structure of microbial communities within the southern CCE. Based on our results, we divided the region into offshore, and inshore northern and southern zones. Mixed-layer phytoplankton communities in the offshore had lower biomass (16±2 μg C L-1; all errors represent the 95% confidence interval), smaller size-class cells and biomass was more stable over seasonal cycles. Offshore phytoplankton biomass peaked during the winter months. Mixed-layer phytoplankton communities in the northern and southern inshore zones had higher biomass (78±22 and 32±9 μg C L-1, respectively), larger size-class cells and stronger seasonal biomass patterns. Inshore communities were often dominated by micro-size (20-200 μm) diatoms; however, autotrophic dinoflagellates dominated during late 2005 to early 2006, corresponding to a year of delayed upwelling in the northern CCE. Biomass trends in mid and deep euphotic zone samples were similar to those seen in the mixed-layer, but with declining biomass with depth, especially for larger size classes in the inshore regions. Mixed-layer ratios of autotrophic carbon to chlorophyll a (AC:Chl a) had a mean value of 51.5±5.3. Variability of nitracline depth, bin-averaged AC:Chl a in the mixed-layer ranged from 40 to 80 and from 22 to 35 for the deep euphotic zone, both with significant positive relationships to nitracline depth. Total living microbial carbon, including auto- and heterotrophs, consistently comprised about half of particulate organic carbon (POC).

  15. Species associations and redundancy in relation to biological hotspots within the northern California Current ecosystem

    NASA Astrophysics Data System (ADS)

    Reese, Douglas C.; Brodeur, Richard D.

    2015-06-01

    The dynamic nature of biological hotspots, while well recognized, is not well understood. We hypothesize that the persistence of hotspots in the northern California Current System (CCS), despite seasonal and annual changes in the nekton community species composition, is related to associations among species and their functional redundancy. To address this hypothesis, sampling was conducted during June and August of 2000 and 2002 within two hotspots occurring between Newport, Oregon and Crescent City, California in the coastal CCS. Associations were examined to identify potentially complementary and redundant species. The strongest negative associations were between jellyfish and fish species, with strong positive associations evident among several fish species. Dominant species varied seasonally and annually, although evidence indicated replacement of dominant species by other similar species with respect to functional group and preferred habitat. This finding suggests that the persistence of these biological hotspots is related to species redundancy and is an important attribute contributing to stability within this highly variable system.

  16. Do inverse ecosystem models accurately reconstruct plankton trophic flows? Comparing two solution methods using field data from the California Current

    NASA Astrophysics Data System (ADS)

    Stukel, Michael R.; Landry, Michael R.; Ohman, Mark D.; Goericke, Ralf; Samo, Ty; Benitez-Nelson, Claudia R.

    2012-03-01

    Despite the increasing use of linear inverse modeling techniques to elucidate fluxes in undersampled marine ecosystems, the accuracy with which they estimate food web flows has not been resolved. New Markov Chain Monte Carlo (MCMC) solution methods have also called into question the biases of the commonly used L2 minimum norm (L 2MN) solution technique. Here, we test the abilities of MCMC and L 2MN methods to recover field-measured ecosystem rates that are sequentially excluded from the model input. For data, we use experimental measurements from process cruises of the California Current Ecosystem (CCE-LTER) Program that include rate estimates of phytoplankton and bacterial production, micro- and mesozooplankton grazing, and carbon export from eight study sites varying from rich coastal upwelling to offshore oligotrophic conditions. Both the MCMC and L 2MN methods predicted well-constrained rates of protozoan and mesozooplankton grazing with reasonable accuracy, but the MCMC method overestimated primary production. The MCMC method more accurately predicted the poorly constrained rate of vertical carbon export than the L 2MN method, which consistently overestimated export. Results involving DOC and bacterial production were equivocal. Overall, when primary production is provided as model input, the MCMC method gives a robust depiction of ecosystem processes. Uncertainty in inverse ecosystem models is large and arises primarily from solution under-determinacy. We thus suggest that experimental programs focusing on food web fluxes expand the range of experimental measurements to include the nature and fate of detrital pools, which play large roles in the model.

  17. Limacina helicina shell dissolution as an indicator of declining habitat suitability owing to ocean acidification in the California Current Ecosystem.

    PubMed

    Bednarek, N; Feely, R A; Reum, J C P; Peterson, B; Menkel, J; Alin, S R; Hales, B

    2014-06-22

    Few studies to date have demonstrated widespread biological impacts of ocean acidification (OA) under conditions currently found in the natural environment. From a combined survey of physical and chemical water properties and biological sampling along the Washington-Oregon-California coast in August 2011, we show that large portions of the shelf waters are corrosive to pteropods in the natural environment. We show a strong positive correlation between the proportion of pteropod individuals with severe shell dissolution damage and the percentage of undersaturated water in the top 100 m with respect to aragonite. We found 53% of onshore individuals and 24% of offshore individuals on average to have severe dissolution damage. Relative to pre-industrial CO2 concentrations, the extent of undersaturated waters in the top 100 m of the water column has increased over sixfold along the California Current Ecosystem (CCE). We estimate that the incidence of severe pteropod shell dissolution owing to anthropogenic OA has doubled in near shore habitats since pre-industrial conditions across this region and is on track to triple by 2050. These results demonstrate that habitat suitability for pteropods in the coastal CCE is declining. The observed impacts represent a baseline for future observations towards understanding broader scale OA effects. PMID:24789895

  18. Limacina helicina shell dissolution as an indicator of declining habitat suitability owing to ocean acidification in the California Current Ecosystem

    PubMed Central

    Bednarek, N.; Feely, R. A.; Reum, J. C. P.; Peterson, B.; Menkel, J.; Alin, S. R.; Hales, B.

    2014-01-01

    Few studies to date have demonstrated widespread biological impacts of ocean acidification (OA) under conditions currently found in the natural environment. From a combined survey of physical and chemical water properties and biological sampling along the WashingtonOregonCalifornia coast in August 2011, we show that large portions of the shelf waters are corrosive to pteropods in the natural environment. We show a strong positive correlation between the proportion of pteropod individuals with severe shell dissolution damage and the percentage of undersaturated water in the top 100 m with respect to aragonite. We found 53% of onshore individuals and 24% of offshore individuals on average to have severe dissolution damage. Relative to pre-industrial CO2 concentrations, the extent of undersaturated waters in the top 100 m of the water column has increased over sixfold along the California Current Ecosystem (CCE). We estimate that the incidence of severe pteropod shell dissolution owing to anthropogenic OA has doubled in near shore habitats since pre-industrial conditions across this region and is on track to triple by 2050. These results demonstrate that habitat suitability for pteropods in the coastal CCE is declining. The observed impacts represent a baseline for future observations towards understanding broader scale OA effects. PMID:24789895

  19. Signs of adaptation to local pH conditions across an environmental mosaic in the California Current Ecosystem.

    PubMed

    Pespeni, M H; Chan, F; Menge, B A; Palumbi, S R

    2013-11-01

    Little is known about the potential for rapid evolution in natural populations in response to the high rate of contemporary climatic change. Organisms that have evolved in environments that experience high variability across space and time are of particular interest as they may harbor genetic variation that can facilitate evolutionary response to changing conditions. Here we review what is known about genetic capacity for adaptation in the purple sea urchin, Strongylocentrotus purpuratus, a species that has evolved in the upwelling ecosystem of the Northeast Pacific Ocean. We also present new results testing for adaptation to local pH conditions in six populations from Oregon to southern California. We integrate data on 19,493 genetic polymorphisms with data on local pH conditions. We find correlations between allele frequency and rank average time spent at pH <7.8 in 318 single-nucleotide polymorphisms in 275 genes. Two of the genes most correlated with local pH are a protein associated with the cytoskeleton and a proton pump, with functional roles in maintenance of cell volume and with internal regulation of pH, respectively. Across all loci tested, high correlations with local pH were concentrated in genes related to transport of ions, biomineralization, lipid metabolism, and cell-cell adhesion, functional pathways important for maintaining homeostasis at low pH. We identify a set of seven genes as top candidates for rapid evolutionary response to acidification of the ocean. In these genes, the putative low-pH-adapted allele, based on allele frequencies in natural populations, rapidly increases in frequency in purple sea urchin larvae raised at low pH. We also found that populations from localities with high pH show a greater change in allele frequency toward putative low-pH-adapted alleles under experimental acidification, compared with low-pH populations, suggesting that both natural and artificial selection favor the same alleles for response to low pH. These results illustrate that purple sea urchins may be adapted to local pH and suggest that this species may possess the genetic capacity for rapid evolution in response to acidification. This adaptive capacity likely comes from standing genetic variation maintained in nature by balancing selection across the spatial and temporal environmental mosaic that characterizes the California Current Ecosystem. PMID:23980118

  20. Top-down modeling and bottom-up dynamics: Linking a fisheries-based ecosystem model with climate hypotheses in the Northern California Current

    NASA Astrophysics Data System (ADS)

    Field, J. C.; Francis, R. C.; Aydin, K.

    2006-02-01

    In this paper we present results from dynamic simulations of the Northern California Current ecosystem, based on historical estimates of fishing mortality, relative fishing effort, and climate forcing. Climate can affect ecosystem productivity and dynamics both from the bottom-up (through short- and long-term variability in primary and secondary production) as well as from the top-down (through variability in the abundance and spatial distribution of key predators). We have explored how the simplistic application of climate forcing through both bottom-up and top-down mechanisms improves the fit of the model dynamics to observed population trends and reported catches for exploited components of the ecosystem. We find that using climate as either a bottom-up or a top-down forcing mechanism results in substantial improvements in model performance, such that much of the variability observed in single species models and dynamics can be replicated in a multi-species approach. Using multiple climate variables (both bottom-up and top-down) simultaneously did not provide significant improvement over a model with only one forcing. In general, results suggest that there do not appear to be strong trophic interactions among many of the longer-lived, slower-growing rockfish, roundfish and flatfish in this ecosystem, although strong interactions were observed in shrimp, salmon and small flatfish populations where high turnover and predation rates have been coupled with substantial changes in many predator populations over the last 40 years.

  1. El Niño and similar perturbation effects on the benthos of the Humboldt, California, and Benguela Current upwelling ecosystems

    NASA Astrophysics Data System (ADS)

    Arntz, W. E.; Gallardo, V. A.; Gutiérrez, D.; Isla, E.; Levin, L. A.; Mendo, J.; Neira, C.; Rowe, G. T.; Tarazona, J.; Wolff, M.

    2006-03-01

    To a certain degree, Eastern Boundary Current (EBC) ecosystems are similar: Cold bottom water from moderate depths, rich in nutrients, is transported to the euphotic zone by a combination of trade winds, Coriolis force and Ekman transport. The resultant high primary production fuels a rich secondary production in the upper pelagic and nearshore zones, but where O2 exchange is restricted, it creates oxygen minimum zones (OMZs) at shelf and upper slope (Humboldt and Benguela Current) or slope depths (California Current). These hypoxic zones host a specifically adapted, small macro- and meiofauna together with giant sulphur bacteria that use nitrate to oxydise H2S. In all EBC, small polychaetes, large nematodes and other opportunistic benthic species have adapted to the hypoxic conditions and co-exist with sulphur bacteria, which seem to be particularly dominant off Peru and Chile. However, a massive reduction of macrobenthos occurs in the core of the OMZ. In the Humboldt Current area the OMZ ranges between <100 and about 600 m, with decreasing thickness in a poleward direction. The OMZ merges into better oxygenated zones towards the deep sea, where large cold-water mega- and macrofauna occupy a dominant role as in the nearshore strip. The Benguela Current OMZ has a similar upper limit but remains shallower. It also hosts giant sulphur bacteria but little is known about the benthic fauna. However, sulphur eruptions and intense hypoxia might preclude the coexistence of significant mega- und macrobenthos. Conversely, off North America the upper limit of the OMZ is considerably deeper (e.g., 500-600 m off California and Oregon), and the lower boundary may exceed 1000m. The properties described are valid for very cold and cold (La Niña and "normal") ENSO conditions with effective upwelling of nutrient-rich bottom water. During warm (El Niño) episodes, warm water masses of low oxygen concentration from oceanic and equatorial regions enter the upwelling zones, bringing a variety of (sub)tropical immigrants. The autochthonous benthic fauna emigrates to deeper water or poleward, or suffers mortality. However, some local macrofaunal species experience important population proliferations, presumably due to improved oxygenation (in the southern hemisphere), higher temperature tolerance, reduced competition or the capability to use different food. Both these negative and positive effects of El Niño influence local artisanal fisheries and the livelihood of coastal populations. In the Humboldt Current system the hypoxic seafloor at outer shelf depths receives important flushing from the equatorial zone, causing havoc on the sulphur bacteria mats and immediate recolonisation of the sediments by mega- and macrofauna. Conversely, off California, the intruding equatorial water masses appear to have lower oxygen than ambient waters, and may cause oxygen deficiency at upper slope depths. Effects of this change have not been studied in detail, although shrimp and other taxa appear to alter their distribution on the continental margin. Other properties and reactions of the two Pacific EBC benthic ecosystems to El Niño seem to differ, too, as does the overall impact of major episodes (e.g., 1982/1983(1984) vs. 1997/1998). The relation of the "Benguela Niño" to ENSO seems unclear although many Pacific-Atlantic ocean and atmosphere teleconnections have been described. Warm, low-oxygen equatorial water seems to be transported into the upwelling area by similar mechanisms as in the Pacific, but most major impacts on the eukaryotic biota obviously come from other, independent perturbations such as an extreme eutrophication of the sediments ensuing in sulphidic eruptions and toxic algal blooms. Similarities and differences of the Humboldt and California Current benthic ecosystems are discussed with particular reference to ENSO impacts since 1972/73. Where there are data available, the authors include the Benguela Current ecosystem as another important, non-Pacific EBC, which also suffers from the effects of hypoxia.

  2. Delta Revival: Restoring a California Ecosystem

    USGS Publications Warehouse

    U.S. Geological Survey; California Bay Delta Authority

    2003-01-01

    'Delta Revival: Restoring a California Ecosystem' shows scientists from many disciplines working together to guide the unprecendented restoration of the Sacramento- San Joaquin Delta east of San Francisco Bay.

  3. Mapping Groundwater Dependent Ecosystems in California

    PubMed Central

    Howard, Jeanette; Merrifield, Matt

    2010-01-01

    Background Most groundwater conservation and management efforts focus on protecting groundwater for drinking water and for other human uses with little understanding or focus on the ecosystems that depend on groundwater. However, groundwater plays an integral role in sustaining certain types of aquatic, terrestrial and coastal ecosystems, and their associated landscapes. Our aim was to illuminate the connection between groundwater and surface ecosystems by identifying and mapping the distribution of groundwater dependent ecosystems (GDEs) in California. Methodology/Principal Findings To locate where groundwater flow sustains ecosystems we identified and mapped groundwater dependent ecosystems using a GIS. We developed an index of groundwater dependency by analyzing geospatial data for three ecosystem types that depend on groundwater: (1) springs and seeps; (2) wetlands and associated vegetation alliances; and (3) stream discharge from groundwater sources (baseflow index). Each variable was summarized at the scale of a small watershed (Hydrologic Unit Code-12; mean size = 9,570 ha; n = 4,621), and then stratified and summarized to 10 regions of relative homogeneity in terms of hydrologic, ecologic and climatic conditions. We found that groundwater dependent ecosystems are widely, although unevenly, distributed across California. Although different types of GDEs are clustered more densely in certain areas of the state, watersheds with multiple types of GDEs are found in both humid (e.g. coastal) and more arid regions. Springs are most densely concentrated in the North Coast and North Lahontan, whereas groundwater dependent wetlands and associated vegetation alliances are concentrated in the North and South Lahontan and Sacramento River hydrologic regions. The percentage of land area where stream discharge is most dependent on groundwater is found in the North Coast, Sacramento River and Tulare Lake regions. GDE clusters are located at the highest percentage in the North Coast (an area of the highest annual rainfall totals), North Lahontan (an arid, high desert climate with low annual rainfall), and Sacramento River hydrologic regions. That GDEs occur in such distinct climatic and hydrologic settings reveals the widespread distribution of these ecosystems. Conclusions/Significance Protection and management of groundwater-dependent ecosystems are hindered by lack of information on their diversity, abundance and location. By developing a methodology that uses existing datasets to locate GDEs, this assessment addresses that knowledge gap. We report here on the application of this method across California, but believe the method can be expanded to regions where spatial data exist. PMID:20585640

  4. The Development of Automated Detection Techniques for Passive Acoustic Monitoring as a Tool for Studying Beaked Whale Distribution and Habitat Preferences in the California Current Ecosystem

    NASA Astrophysics Data System (ADS)

    Yack, Tina M.

    The objectives of this research were to test available automated detection methods for passive acoustic monitoring and integrate the best available method into standard marine mammal monitoring protocols for ship based surveys. The goal of the first chapter was to evaluate the performance and utility of PAMGUARD 1.0 Core software for use in automated detection of marine mammal acoustic signals during towed array surveys. Three different detector configurations of PAMGUARD were compared. These automated detection algorithms were evaluated by comparing them to the results of manual detections made by an experienced bio-acoustician (author TMY). This study provides the first detailed comparisons of PAMGUARD automated detection algorithms to manual detection methods. The results of these comparisons clearly illustrate the utility of automated detection methods for odontocete species. Results of this work showed that the majority of whistles and click events can be reliably detected using PAMGUARD software. The second chapter moves beyond automated detection to examine and test automated classification algorithms for beaked whale species. Beaked whales are notoriously elusive and difficult to study, especially using visual survey methods. The purpose of the second chapter was to test, validate, and compare algorithms for detection of beaked whales in acoustic line-transect survey data. Using data collected at sea from the PAMGUARD classifier developed in Chapter 2 it was possible to measure the clicks from visually verified Baird's beaked whale encounters and use this data to develop classifiers that could discriminate Baird's beaked whales from other beaked whale species in future work. Echolocation clicks from Baird's beaked whales, Berardius bairdii, were recorded during combined visual and acoustic shipboard surveys of cetacean populations in the California Current Ecosystem (CCE) and with autonomous, long-term recorders at four different sites in the Southern California Bight (SCB). The preliminary measurement of the visually validated Baird's beaked whale echolocation signals recorded from the ship-based towed array were used as a basis for identifying Baird's signals in the seafloor-mounted autonomous recorder data. The passive acoustic detection algorithms for beaked whales developed using data from Chapters 2 and 3 were field tested during a three year period to test the reliability of acoustic beaked whale monitoring techniques and to use these methods to describe beaked whale habitat in the SCB. In 2009 and 2010, PAM methods using towed hydrophone arrays were tested. These methods proved highly effective for real-time detection of beaked whales in the SCB and were subsequently implemented in 2011 to successfully detect and track beaked whales during the ongoing Southern California Behavioral Response Study (SOCAL-BRS). The final step in this research was to utilize the passive acoustic detection techniques developed herin to predictively model beaked whale habitat use and preferences in the CCE. This chapter uses a multifaceted approach to model beaked whale encounter rates in the CCE. Beaked whale acoustic encounters are utilized to inform Generalized Additive Models (GAMs) of encounter rate for beaked whales in the CCE and compare these to visual based models. Acoustic and visual based models were independently developed for a small beaked whale group and Baird's beaked whales. Two models were evaluated for visual and acoustic encounters, one that also included Beaufort sea state as a predictor variable in addition to those listed and one that did not include Beaufort sea state. (Abstract shortened by UMI.)

  5. California current system - Predators and the preyscape

    NASA Astrophysics Data System (ADS)

    Ainley, David G.; Adams, Peter B.; Jahncke, Jaime

    2015-06-01

    The preyscape of the California Current System (CCS), one of the most productive marine areas on Earth (Glantz and Thompson, 1981), is highly variable, as evidenced by the papers in this issue, and as such presents a challenge to Ecosystem-based fishery management (EBFM), which attempts to integrate ecosystem considerations as part of fishery management and conservation decisions. Approaches to EBFM for the waters off Washington, Oregon, and California, the CCS, have been initiated (PFMC, 2007, 2013), and are continually being developed. To inform this process, a workshop was held in September 2013 to: i) gather together the existing information on forage fish and predator dynamics in the CCS; ii) consider temporal (seasonal, annual, decadal) and spatial availability of prey complexes and why these patterns of availability occur and change; iii) summarize and present that information for discussion to a large range of experts in oceanography, fish and fisheries management, seabirds, marine mammals, and ecosystem management; and, iv) synthesize this information to be useable by fishery agencies. The papers in this special Journal of Marine Systems issue address these four points. While the full results and recommendations can be found here - "http://www.pointblue.org/uploads/assets/calcurrent/REPORT_Forage_Fish_Workshop_FINAL.pdf"

  6. Predictability of the California Current System

    NASA Technical Reports Server (NTRS)

    Miller, Arthur J.; Chereskin, T.; Cornuelle, B. D.; Niiler, P. P.; Moisan, J. R.; Lindstrom, Eric (Technical Monitor)

    2001-01-01

    The physical and biological oceanography of the Southern California Bight (SCB), a highly productive subregion of the California Current System (CCS) that extends from Point Conception, California, south to Ensenada, Mexico, continues to be extensively studied. For example, the California Cooperative Oceanic Fisheries Investigations (CalCOFI) program has sampled this region for over 50 years, providing an unparalleled time series of physical and biological data. However, our understanding of what physical processes control the large-scale and mesoscale variations in these properties is incomplete. In particular, the non-synoptic and relatively coarse spatial sampling (70km) of the hydrographic grid does not completely resolve the mesoscale eddy field (Figure 1a). Moreover, these unresolved physical variations exert a dominant influence on the evolution of the ecosystem. In recent years, additional datasets that partially sample the SCB have become available. Acoustic Doppler Current Profiler (ADCP) measurements, which now sample upper-ocean velocity between stations, and sea level observations along TOPEX tracks give a more complete picture of the mesoscale variability. However, both TOPEX and ADCP are well-sampled only along the cruise or orbit tracks and coarsely sampled in time and between tracks. Surface Lagrangian drifters also sample the region, although irregularly in time and space. SeaWiFS provides estimates of upper-ocean chlorophyll-a (chl-alpha), usually giving nearly complete coverage for week-long intervals, depending on cloud coverage. Historical ocean color data from the Coastal Zone Color Scanner (CZCS) has been used extensively to determine phytoplankton patterns and variability, characterize the primary production across the SCB coastal fronts, and describe the seasonal and interannual variability in pigment concentrations. As in CalCOFI, these studies described much of the observed structures and their variability over relatively large space and time scales.

  7. Interdisciplinary modeling of the California Current System

    NASA Astrophysics Data System (ADS)

    Edwards, C. A.; Veneziani, M.; Broquet, G.; Goebel, N.; Moore, A. M.; Zehr, J. P.; Follows, M.

    2008-12-01

    The California Current System (CCS) refers to the collection of poleward and equatorward surface and subsurface currents that extends along the west coast of North America and a thousand kilometers offshore where it merges with the larger Pacific circulation. It exhibits strong seasonal fluctuations and rich mesoscale variability and supports a productive and diverse ecosystem with geographically varying communities. We report on the development and evaluation of an interdisciplinary modeling effort for this region. For the physical model, we use the Regional Ocean Modeling System, driven at the surface by output from the Coupled Ocean Atmosphere Mesoscale Prediction System and coupled at the lateral boundaries to GODAE- derived fields from the project, Estimating the Circulation and Climate of the Ocean. The forward physical model is evaluated using in situ hydrographic measurements and satellite-derived data. An incremental, strong-constraint, 4-dimensional variational approach assimilates this data, with evaluations based on model- data error statistics of both analysis and forecast fields. The ecosystem model, run in the forward model, supports 78 phytoplankton species and demonstrates self-organizing behavior. We focus this talk on the challenges associated with complex model evaluation in the coastal ocean. ~

  8. Taxonomic Distinctness of Demersal Fishes of the California Current: Moving Beyond Simple Measures of Diversity for Marine Ecosystem-Based Management

    PubMed Central

    Tolimieri, Nick; Anderson, Marti J.

    2010-01-01

    Background Large-scale patterns or trends in species diversity have long interested ecologists. The classic pattern is for diversity (e.g., species richness) to decrease with increasing latitude. Taxonomic distinctness is a diversity measure based on the relatedness of the species within a sample. Here we examined patterns of taxonomic distinctness in relation to latitude (ca. 32–48 °N) and depth (ca. 50–1220 m) for demersal fishes on the continental shelf and slope of the US Pacific coast. Methodology/Principal Findings Both average taxonomic distinctness (AvTD) and variation in taxonomic distinctness (VarTD) changed with latitude and depth. AvTD was highest at approximately 500 m and lowest at around 200 m bottom depth. Latitudinal trends in AvTD were somewhat weaker and were depth-specific. AvTD increased with latitude on the shelf (50–150 m) but tended to decrease with latitude at deeper depths. Variation in taxonomic distinctness (VarTD) was highest around 300 m. As with AvTD, latitudinal trends in VarTD were depth-specific. On the shelf (50–150 m), VarTD increased with latitude, while in deeper areas the patterns were more complex. Closer inspection of the data showed that the number and distribution of species within the class Chondrichthyes were the primary drivers of the overall patterns seen in AvTD and VarTD, while the relatedness and distribution of species in the order Scorpaeniformes appeared to cause the relatively low observed values of AvTD at around 200 m. Conclusions/Significance These trends contrast to some extent the patterns seen in earlier studies for species richness and evenness in demersal fishes along this coast and add to our understanding of diversity of the demersal fishes of the California Current. PMID:20498727

  9. Through the stomach of a predator: Regional patterns of forage in the diet of albacore tuna in the California Current System and metrics needed for ecosystem-based management

    NASA Astrophysics Data System (ADS)

    Glaser, Sarah M.; Waechter, Katrina E.; Bransome, Nicole C.

    2015-06-01

    Foraging habits of predators can reveal patterns in prey ecology and guide ecosystem-based management by informing species interactions. This study describes the diet habits of albacore tuna in three regions (north, central, south) of the California Current System (CCS) and estimates the total predation mortality imposed on twenty prey taxa. The northern CCS was defined by predation on decapods, euphausiids, anchovy and hake. The central CCS was defined by predation on squid, hake and Pacific saury. The southern CCS was defined by predation on anchovy. We estimate North Pacific albacore consumed each year, on average, 54,000 mt of decapods and euphausiids, 43,000 mt of cephalopods, 84,000 mt of juvenile hake, 1600 mt of myctophids, 21,000 mt of juvenile sardine, 10,000 mt of juvenile rockfishes, almost 43,000 mt of Pacific saury, and over 107,000 mt of juvenile anchovy. While variability in predation certainly exists, this and prior studies show that diet habits of albacore are fairly stable through time. The northern CCS appears to be a more significant source of energy for albacore. When designing ecosystem-based approaches to the management of CCS-based fisheries, we recommend that the forage contribution of saury, hake and anchovy to the albacore population be considered.

  10. Water use efficiency variability and controls across ten California ecosystems

    NASA Astrophysics Data System (ADS)

    Kelly, A. E.; Goulden, M.

    2014-12-01

    Intensification of the hydrologic cycle is predicted with future climate change, and the consequences for ecosystem carbon cycling is a critical question in predicting ecohydrological feedbacks. We analyzed eddy covariance measurements to understand how interannual and inter-site variability in precipitation affects gross primary production, evapotranspiration, and ecosystem water use efficiency (WUE) across diverse ecosystems. Measurements came from ten California sites and spanned a mean annual temperature range of 5 to 23C and mean annual precipitation range of 100 to 1400 mm, from Mojave Desert scrub to subalpine lodgepole forest. All ten ecosystems exhibited similar patterns in water use efficiency: ecosystem WUE declined sharply as annual precipitation dropped below 500 mm, and WUE plateaued with annual precipitation greater than 500 mm. Surface evaporation and flexible plant physiology contributed to sensitive WUE with low annual precipitation, while limited surface evaporation and "ecosystem inertia" diminished sensitivity of WUE with high annual precipitation.

  11. Where California Meets Alaska: Ecosystem Response in a Transition Zone

    NASA Astrophysics Data System (ADS)

    Crawford, W.; Pena, A.; Irvine, J. R.

    2008-12-01

    Ecosystems along the west coast of Vancouver Island share features with those of the northern California Current and also with the southern part of the Alaska Coastal Current, and provide the richest fisheries of these two regimes. Studies of the past few decades reveal surprisingly consistent biological responses to changes in ocean temperatures, partly due to the extreme warm and cool years since 1998. Zooplankton populations, migrating salmon, and fledgling seabirds are rapidly affected by changing ocean conditions, whereas the biomass of resident fish stocks responds over several years or even decades. The specific mechanisms responsible for these temperature-related changes vary from species to species, and many are unknown. We will present examples of how influx of predators, timing of food availability, and wind and coastal weather contribute to the response of coastal populations. Results are based on statistical analyses of many decades of observations and also on biophysical models. The responses to past temperature variability suggest which species will eventually thrive with climate warming and the speed with which these changes might occur. One unresolved factor is the ability of cold water species to survive and rebound after warm years, and of warm-water species to recover after cold years. These responses will be increasingly important, because the IPCC models suggest increasing local ocean temperature variability during this century.

  12. Future scenarios of impacts to ecosystem services on California rangelands

    USGS Publications Warehouse

    Byrd, Kristin; Alvarez, Pelayo; Flint, Lorraine; Flint, Alan

    2014-01-01

    The 18 million acres of rangelands in the Central Valley of California provide multiple benefits or “ecosystem services” to people—including wildlife habitat, water supply, open space, recreation, and cultural resources. Most of this land is privately owned and managed for livestock production. These rangelands are vulnerable to land-use conversion and climate change. To help resource managers assess the impacts of land-use change and climate change, U.S. Geological Survey scientists and their cooperators developed scenarios to quantify and map changes to three main rangeland ecosystem services—wildlife habitat, water supply, and carbon sequestration. Project results will help prioritize strategies to conserve these rangelands and the ecosystem services that they provide.

  13. 75 FR 6696 - Draft Recovery Plan for Tidal Marsh Ecosystems of Northern and Central California

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

    ... Fish and Wildlife Service Draft Recovery Plan for Tidal Marsh Ecosystems of Northern and Central... draft recovery plan for Tidal Marsh Ecosystems of Northern and Central California for public review and... Marsh Ecosystems of Northern and Central California features five endangered species. The biology...

  14. Climate-ecosystem change off southern California: Time-dependent seabird predator-prey numerical responses

    NASA Astrophysics Data System (ADS)

    Sydeman, William J.; Thompson, Sarah Ann; Santora, Jarrod A.; Koslow, J. Anthony; Goericke, Ralf; Ohman, Mark D.

    2015-02-01

    Climate change may increase both stratification and upwelling in marine ecosystems, but these processes may affect productivity in opposing or complementary ways. For the Southern California region of the California Current Ecosystem (CCE), we hypothesized that changes in stratification and upwelling have affected marine bird populations indirectly through changes in prey availability. To test this hypothesis, we derived trends and associations between stratification and upwelling, the relative abundance of potential prey including krill and forage fish, and seabirds based on the long-term, multi-disciplinary CalCOFI/CCE-LTER program. Over the period 1987 through 2011, spring and summer seabird density (all species combined) declined by ~2% per year, mostly in the northern sector of the study region. Krill showed variable trends with two species increasing and one deceasing, resulting in community reorganization. Nearshore forage fish, dominated by northern anchovy (Engraulis mordax) as well as offshore mesopelagic species, show declines in relative abundance over this period. The unidirectional decline in springtime seabird density is largely explained by declining nearshore fish abundance in the previous season (winter). Interannual variability in seabird density, especially in the 2000s, is explained by variability in krill abundance. Changes in the numerical responses of seabirds to prey abundance correspond to a putative ecosystem shift in 1998-1999 and support aspects of optimal foraging (diet) theory. Predator-prey interactions and numerical responses clearly explain aspects of the upper trophic level patterns of change in the pelagic ecosystem off southern California.

  15. Measuring Tsunami Current Velocities on Californias North Coast

    NASA Astrophysics Data System (ADS)

    Crawford, G. B.; Dengler, L. A.; Montoya, J.

    2009-12-01

    The Northern California coast is particularly susceptible to tsunami damage. Thirty-one tsunamis have been recorded since 1933 when the first tide gauge was installed at Citizens Dock in Crescent City, California and four have caused damage. In November 2006, a magnitude 8.3 earthquake in the Kuril Islands generated a tsunami that caused over $20 million in damages and replacement costs to the Crescent City small boat basin. The 2006 tsunami did not flood any areas above the normal high tide; very strong currents produced as the tsunami surged in and out of the small boat basin caused all of the damage. The Harbor Master and commercial fishermen in the area estimated the peak currents near the mouth of the small boat basin at 12 to 15 knots or 6 to 8 m/sec. MOST numerical modeling of the 2006 currents in Crescent City gives peak velocities in the 2-3 m/sec range. We have initiated a pilot project to directly measure current velocities produced by moderate tsunamis such as the 2006 event. In spring of 2009 we acquired a Nortek Aquadopp 600 kHz acoustic 2-D current profiler through a donation from the Pacific Gas and Electric Company to measure currents in Humboldt Bay, located 100 km south of Crescent City. The manufacturer specifies the current meter can measure currents up to 10 m/sec. In a preliminary deployment at the Fairhaven dock inside Humboldt Bay in May 2009, we measured current velocities of 1.5 m/sec caused by the daily tidal fluctuation with a 1 minute sampling rate. Our primary goal is to model control and data telemetry of this current meter after NOAAs tsunami-ready tide gages, in collaboration with NOAA personnel at PMEL and CO-OPS. We also intend to make available real-time current measurements online for the local maritime community. In this poster, we present preliminary results from the current meter and discuss deployment and telecommunication considerations. While some interference is present in the closest range bins, the system measures currents in the nearby navigational channel that compare favorably to NOAA tidal predictions at a nearby location. Once the deployment and telemetry issues have been resolved at the Humboldt Bay site, we will be deploying two additional instruments in Crescent City.

  16. Modeling phytoplankton growth rates and chlorophyll to carbon ratios in California coastal and pelagic ecosystems

    NASA Astrophysics Data System (ADS)

    Li, Qian P.; Franks, Peter J. S.; Landry, Michael R.; Goericke, Ralf; Taylor, Andrew G.

    2010-12-01

    To understand and quantify plankton community dynamics in the ocean, high-resolution models are needed to capture the temporal and spatial variations of physical, biological, and biogeochemical processes. However, ecosystem models often fail to agree with observations. This failure can be due to inadequacies in the data and/or inadequacies in the model formulation and parameterization. Here we parameterize and optimize a two-phytoplankton functional type model of phytoplankton growth rate and chlorophyll/carbon (Chl:C) ratio using data from the Lagrangian field measurements conducted during process cruises of the Long-Term Ecosystem Research-California Current Ecosystem (CCE) program. We parameterize the model based on a small coastal subset of the data and then extend and test it with the full data set, including data from offshore regions. The CCE process studies were focused on quantifying the size-resolved planktonic growth, grazing, production, and export rates while following water parcels. The resulting data therefore provided strong constraints for the model we employed. The modeled growth rates and Chl:C ratios were in good agreement with observations. Our results indicate that the model can accurately predict Chl:C ratios, biomasses, and growth rates of dominant functional types using relatively easily measured environmental variables (temperature, nutrients, and bulk chlorophyll). The model also accurately reproduces the subsurface maxima of growth rates, the spatial separation of carbon and chlorophyll maxima, and many other observations in the California Current coastal and pelagic ecosystems.

  17. Whither the Rangeland?: Protection and Conversion in California's Rangeland Ecosystems

    PubMed Central

    Cameron, D. Richard; Marty, Jaymee; Holland, Robert F.

    2014-01-01

    Land use change in rangeland ecosystems is pervasive throughout the western United States with widespread ecological, social and economic implications. In California, rangeland habitats have high biodiversity value, provide significant habitat connectivity and form the foundation for a number of ecosystem services. To comprehensively assess the conservation status of these habitats, we analyzed the extent and drivers of habitat loss and the degree of protection against future loss across a 13.5 M ha study area in California. We analyzed rangeland conversion between 1984 and 2008 using time series GIS data and classified resulting land uses with aerial imagery. In total, over 195,000 hectares of rangeland habitats were converted during this period. The majority of conversions were to residential and associated commercial development (49% of the area converted), but agricultural intensification was surprisingly extensive and diverse (40% across six categories). Voluntary enrollment in an agricultural tax incentive program provided widespread protection from residential and commercial conversions across 37% of the remaining rangeland habitat extent (7.5 M ha), though this program did not protect rangeland from conversion to more intensive agricultural uses. Additionally, 24% of the remaining rangeland was protected by private conservation organizations or public agencies through land or easement ownership while 38% had no protection status at all. By developing a spatial method to analyze the drivers of loss and patterns of protection, this study demonstrates a novel approach to prioritize conservation strategies and implementation locations to avert habitat conversion. We propose that this approach can be used in other ecosystem types, and can serve as a regional conservation baseline assessment to focus strategies to effect widespread, cost-effective conservation solutions. PMID:25141171

  18. Avian Conservation Practices Strengthen Ecosystem Services in California Vineyards

    PubMed Central

    Jedlicka, Julie A.; Greenberg, Russell; Letourneau, Deborah K.

    2011-01-01

    Insectivorous Western Bluebirds (Sialia mexicana) occupy vineyard nest boxes established by California winegrape growers who want to encourage avian conservation. Experimentally, the provision of available nest sites serves as an alternative to exclosure methods for isolating the potential ecosystem services provided by foraging birds. We compared the abundance and species richness of avian foragers and removal rates of sentinel prey in treatments with songbird nest boxes and controls without nest boxes. The average species richness of avian insectivores increased by over 50 percent compared to controls. Insectivorous bird density nearly quadrupled, primarily due to a tenfold increase in Western Bluebird abundance. In contrast, there was no significant difference in the abundance of omnivorous or granivorous bird species some of which opportunistically forage on grapes. In a sentinel prey experiment, 2.4 times more live beet armyworms (Spodoptera exigua) were removed in the nest box treatment than in the control. As an estimate of the maximum foraging services provided by insectivorous birds, we found that larval removal rates measured immediately below occupied boxes averaged 3.5 times greater than in the control. Consequently the presence of Western Bluebirds in vineyard nest boxes strengthened ecosystem services to winegrape growers, illustrating a benefit of agroecological conservation practices. Predator addition and sentinel prey experiments lack some disadvantages of predator exclusion experiments and were robust methodologies for detecting ecosystem services. PMID:22096555

  19. Assessing Nitrate Deposition in Southern California Ecosystems using ?17O.

    NASA Astrophysics Data System (ADS)

    Hernandez, L.; Michalski, G.; Meixner, T.; Fenn, M.; Thiemens, M. H.

    2002-12-01

    Assessing the impact of atmospheric deposition of fixed nitrogen on local, regional, and global biogeochemical cycles has received much attention in recent years. Local and regional ecosystems can suffer from eutrophication and shrinking biodiversity from the increased nitrogen flux, in addition to degradation associated with acid rain (an increasing proportion of which is as HNO3 ). On a global scale, the effect of nitrogen fertilization on CO2 uptake rates is one of the biggest unknowns in global warming research. This renewed interest has led to new attempts to utilize current, and in the development of new, analytical techniques in order to better understand the source, sink and transport mechanisms of atmospheric nitrogen deposition. Stable isotopes of nitrogen and oxygen have been used to trace atmospheric nitrate through the biogeochemical system. 15N ratios have been problematic due to the lack of large fractionations and an overlap of 15N ratios between sources. Initial studies of 18O ratios showed promise due to the large enrichment (60 ) in atmospheric nitrate. However, subsequent studies showed an ? 18O spread of 25 - 80 and have made quantitative analysis of mixing reservoirs difficult. Atmospheric nitrates have now been measured and have been found to have a large MIF; ?17O ~ 25 and a small range +/- 4 . The large variations in ? 18O that may result from post depositional fractionations associated with soil migration and microbial utilization are mass dependent processes and leave the ?17O unaffected. It can therefore be used as a conservative trace of atmospheric nitrate deposition. A preliminary study of the southern California coastal sage scrub and alpine forest habitat examined the variability and detect- ability of nitrate deposition using ?17O. Nitrate from atmospheric aerosols, nitric acid vapor, and wet deposition all had ?17O values in the same range as other studies: 25 . Surface soils showed large deposition contributions to total N. Soil lysimeter measurements revealed large ? 18O depletions indicating large fractionation factors from soil uptake. Stream water also exhibited low ? 18O values, but significant ?17O values 0-6 indicating atmospheric contributions of 0 to 20 %. Observations of low ? 18O (10 ) in streams where the ?17O indicate in excess of 20 % deposition suggest a reevaluation of studies which used ? 18O as a tracer of nitrate deposition.

  20. Chlorocarbon Fluxes in Coastal and Upland Ecosystems of California

    NASA Astrophysics Data System (ADS)

    Rhew, R. C.; Mazéas, O.; Miller, B. R.; Pingatore, C.; Weiss, R. F.

    2007-12-01

    Anthropogenic chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) account for ~ 70% of the organic chlorine in the global atmosphere, with CH3Cl (methyl chloride), CHCl3 (chloroform), CCl4 (carbon tetrachloride) and CH3CCl3 (methyl chloroform) supplying most of the balance. Since 1994, the total atmospheric chlorine burden has been decreasing, owing in large part to the declining concentrations of CH3CCl3 and CCl4, two chlorocarbons regulated by the Montreal Protocol. The primary sink of all four compounds is attributed to destruction processes in the atmosphere (oxidation or photodissociation). However, several recent studies have reported a potentially significant terrestrial sink for CH3Cl, CCl4 and CH3CCl3. Particularly surprising is the report that coastal salt marshes in China appear to be net sinks for all four of these chlorocarbons. If these sinks are indeed significant relative to atmospheric destruction processes, then their estimated lifetimes would need to be reduced and their source and sink budgets reassessed. In this study, we report net fluxes of CHCl3, CCl4, and CH3CCl3 from a variety of southern California ecosystems, including coast sagebrush, chamise chaparral, creosote bush scrub, shoreline, and coastal salt marsh. 75 flux chamber measurements were conducted between 1997 and 2000. We find no evidence of a significant soil sink in these ecosystems but rather a small net source of CHCl3 and CCl4. Meanwhile, previously reported CH3Cl fluxes from these ecosystems show that coastal salt marshes are large sources of this compound while shrublands act as either a net source or sink, depending on predominant vegetation, soil conditions and season. To address the possibility of simultaneous production and consumption of CH3Cl in salt marshes, we employed a stable isotope tracer technique at a northern California salt marsh during the spring of 2007. We measured gross consumption rates of CH3Cl, but gross production rates were much greater at all sites, resulting in large net emissions overall. We suggest that salt marshes are typically net sources of CH3Cl and CHCl3 but may become net sinks if ambient concentrations of these compounds are unusually high, as reported from the salt marshes in China.

  1. The Gulf of California: Review of ecosystem status and sustainability challenges

    NASA Astrophysics Data System (ADS)

    Lluch-Cota, Salvador E.; Aragón-Noriega, Eugenio A.; Arreguín-Sánchez, Francisco; Aurioles-Gamboa, David; Jesús Bautista-Romero, J.; Brusca, Richard C.; Cervantes-Duarte, Rafael; Cortés-Altamirano, Roberto; Del-Monte-Luna, Pablo; Esquivel-Herrera, Alfonso; Fernández, Guillermo; Hendrickx, Michel E.; Hernández-Vázquez, Sergio; Herrera-Cervantes, Hugo; Kahru, Mati; Lavín, Miguel; Lluch-Belda, Daniel; Lluch-Cota, Daniel B.; López-Martínez, Juana; Marinone, Silvio G.; Nevárez-Martínez, Manuel O.; Ortega-García, Sofia; Palacios-Castro, Eduardo; Parés-Sierra, Alejandro; Ponce-Díaz, Germán; Ramírez-Rodríguez, Mauricio; Salinas-Zavala, Cesar A.; Schwartzlose, Richard A.; Sierra-Beltrán, Arturo P.

    2007-04-01

    The Gulf of California is unique because of its geographical location and conformation. It hosts diverse ecosystems and important fisheries that support industry and provide livelihood to coastal settlements. It is also the site of interests and problems, and an intense interaction among managers, producers, and conservationists. In this report, we scrutinize the abiotic (hydrography, climate, ocean circulation, and chemistry) and biotic (phyto- and zooplankton, fish, invertebrates, marine mammals, birds, and turtles) components of the marine ecosystem, and some particular aspects of climate variability, endemisms, harmful algal blooms, oxygen minimum layer, and pollution. We also review the current conditions and conflicts around the main fisheries (shrimp, small and large pelagic fishes, squid, artisanal and sportfishing), the most important human activity in the Gulf of California. We cover some aspects of management and conservation of fisheries, especially the claimed overexploitation of fish resources and the ecosystems, and review proposals for creating networks of marine protected areas. We conclude by identifying main needs for information and research, particularly the integration of data bases, the implementation of models and paleoreconstructions, establishment of monitoring programs, and the evaluation of fishing impacts and management actions.

  2. Persistence of chlorinated hydrocarbon contamination in a California marine ecosystem

    SciTech Connect

    Young, D.R.; Gossett, R.W.; Heesen, T.C.

    1989-01-01

    Despite major reductions in the dominant DDT and polychlorinated biphenyls (PCB) input off Los Angeles (California, U.S.A.) in the early 1970s, the levels of these pollutants decreased only slightly from 1972 to 1975 both in surficial bottom sediments and in a flatfish bioindicator (Dover sole, Microstomus pacificus) collected near the submarine outfall. Concentrations of these pollutants in the soft tissues of the mussel Mytilus californianus, collected intertidally well inshore of the highly contaminated bottom sediments, followed much more closely the decreases in the outfall discharges. These observations suggest that contaminated sediments on the seafloor were the principal (although not necessarily direct) cause of the relatively high and persistent concentrations of DDT and PCB residues in tissues. The study indicated that residues of the higher-molecular-weight chlorinated hydrocarbons, such as DDT and PCB, can be highly persistent once released to coastal marine ecosystems and that their accumulation in surficial bottom sediments is the most likely cause of this persistence observed in the biota of the discharge zone.

  3. Ecosystem Change in California Grasslands: Impacts of Species Invasion

    NASA Astrophysics Data System (ADS)

    Koteen, L. E.; Harte, J.; Baldocchi, D. D.

    2009-12-01

    Grassland ecosystems of California have undergone dramatic changes, resulting in the almost complete replacement of native perennial grasses by non-native annuals across millions of hectares of grassland habitat. Our research investigates the effects of this community shift on carbon, water and energy cycles at two sites in northern coastal California. Our goal was to understand how changes to California’s grasslands have affected climate through 1. shifting the balance of carbon storage between terrestrial stocks and the atmosphere, and 2. altering the water and energy regimes that heat or cool the earth's surface. To compare the processes that govern material exchange before and after annual grass invasion, we made use of sites where native vegetation is found adjacent to locations that have undergone non-native invasion. In plots of each vegetation type, we monitored whole plant productivity, root and litter decay rates and soil respiration, as well as soil climatic controls on these processes. At one site, we also measured surface albedo and the components of the surface energy balance in each grass community, using the surface renewal method. Although seemingly subtle, the shift in California grassland communities from native perennial to non-native annual grass dominance has had profound consequences for ecosystem biogeochemical, radiative and hydrological cycles. Soil carbon storage was found to be significantly greater in native perennial grass communities. Across both study sites, we found that non-native grass invasion has resulted in the transfer of from 3 to 6 tons of carbon per hectare from the soil to the atmosphere, dependent on site and species. A soil density fractionation and a radiocarbon analysis also revealed the carbon to be more recalcitrant in native grass dominated locations. The primary plant traits that help explain why soil carbon losses follow annual grass invasion are: 1. differences between annual and perennial grasses in above/ belowground allocation, 2. differences in growth plasticity in response to inter-annual precipitation variability, and 3. the effect of differences in rooting depth and aboveground morphology on soil moisture content and soil respiration. Over the years 2004-2006, we found energy partitioning into latent and sensible heat flux to be similar among annual and perennial grass communities during periods of sufficient soil moisture availability. When water becomes scarce in the late spring, however, and annual grasses die, the ratio of latent to sensible heat loss is reduced in annual grass communities relative to perennials. The deep roots of perennial grasses prolong the period over which transpiration occurs. We also found that albedo differs year-round between perennial and annual grasses, tracking differences in grass phenology. Albedo differences are at a maximum during the summer and autumn months. At this time, the lower albedo in non-native annual communities can raise near surface temperatures up to 6 oC midday relative to native perennials.

  4. Predator-Driven Nutrient Recycling in California Stream Ecosystems

    PubMed Central

    Munshaw, Robin G.; Palen, Wendy J.; Courcelles, Danielle M.; Finlay, Jacques C.

    2013-01-01

    Nutrient recycling by consumers in streams can influence ecosystem nutrient availability and the assemblage and growth of photoautotrophs. Stream fishes can play a large role in nutrient recycling, but contributions by other vertebrates to overall recycling rates remain poorly studied. In tributaries of the Pacific Northwest, coastal giant salamanders (Dicamptodon tenebrosus) occur at high densities alongside steelhead trout (Oncorhynchus mykiss) and are top aquatic predators. We surveyed the density and body size distributions of D. tenebrosus and O. mykiss in a California tributary stream, combined with a field study to determine mass-specific excretion rates of ammonium (N) and total dissolved phosphorus (P) for D. tenebrosus. We estimated O. mykiss excretion rates (N, P) by bioenergetics using field-collected data on the nutrient composition of O. mykiss diets from the same system. Despite lower abundance, D. tenebrosus biomass was 2.5 times higher than O. mykiss. Mass-specific excretion summed over 170 m of stream revealed that O. mykiss recycle 1.7 times more N, and 1.2 times more P than D. tenebrosus, and had a higher N:P ratio (8.7) than that of D. tenebrosus (6.0), or the two species combined (7.5). Through simulated trade-offs in biomass, we estimate that shifts from salamander biomass toward fish biomass have the potential to ease nutrient limitation in forested tributary streams. These results suggest that natural and anthropogenic heterogeneity in the relative abundance of these vertebrates and variation in the uptake rates across river networks can affect broad-scale patterns of nutrient limitation. PMID:23520520

  5. The Economic Value of Coastal Ecosystems in California

    EPA Science Inventory

    The status of marine ecosystems affects the well being of human societies. These ecosystems include but are not limited to estuaries, lagoons, reefs, and systems further offshore such as deep ocean vents. The coastal regions that connect terrestrial and marine ecosystems are of p...

  6. Responses of soil respiration to elevated CO[sub 2] in two California grassland ecosystems

    SciTech Connect

    Luo, Y.; Jackson, R.B.; Field, C.B.; Mooney, H.A. )

    1994-06-01

    Estimates of soil respiration (SR) in current and elevated CO[sub 2] are critical for predicting future global carbon budgets. We measured SR in two California grassland ecosystems (sandstone and serpentine) growing at ambient and ambient+350 ppm CO[sub 2]. SR was higher in elevated CO[sub 2] for both ecosystems in the field, but differences were not significant. At peak plant growth, SR was approximately 6 [mu]mol m[sup [minus]2]s[sup [minus]1] in elevated CO[sub 2] and 5 [mu]mol m[sup [minus]2] s[sup [minus]1] in ambient CO[sub 2] for both ecosystems. We also examined soil respiration in monocultures of 7 grassland species grown in microecosystems (10-cm diameter by 1-m deep tubes). SR was approximately 2 [mu]mol m[sup [minus]2]s[sup [minus]1] for Plantago, Bromus, Hemizona, and Calycadenia and 7 [minus] 8 [mu]mol m[sup [minus]2]s[sup [minus]2] for Lolium, Avena, and Vulpia. Elevated CO[sub 2] significantly increased soil respiration by 20-30% in Bromus, Hemizonia and Lolium monocultures. SR was significantly correlated with total plant biomass as averaged across all species.

  7. A long term monitoring of Net Ecosystem Exchanges of the chaparral ecosystem in Southern California

    NASA Astrophysics Data System (ADS)

    Rossi, A.; Oechel, W. C.; Murphy, P.; Ikawa, H.; Sturtevant, C. S.

    2012-12-01

    Arid and semiarid woody shrublands represent approximately 35% of the global terrestrial surface area and 24% of the global soil organic carbon, and 16% of the global aboveground biomass (Atjay et al., 1979; Shmida, 1985). Therefore, these areas potentially have a large contribution to the global carbon budget. However, the assessment of carbon uptake for the old-growth shrubland has remained largely unexplored. Therefore, a long-term observation of CO2 flux with the eddy covariance technique has started since 1997 at Sky Oaks Field Station in Southern California. The research site is categorized at the climatic gradient between desert and semiarid area and that experiences a Mediterranean climate. The long term record of CO2 flux showed the area has been a sink of CO2 of up to -0.2 kgCm-2yr-1. In addition to evaluating vertical carbon fluxes, we initiated a project to evaluate lateral carbon transports using litter traps, sediment fences and two small weirs adjacent to the eddy covariance site in 2011. Preliminary results indicate that the lateral carbon efflux from the system may offset the vertical influx to the shrub ecosystem. However, it is still necessary to develop the methodology to compare vertical carbon flux and the lateral carbon fluxes more accurately.

  8. Carbon Cycling Studies in Forest and Rangeland Ecosystems of Northern and Central Coastal California

    NASA Astrophysics Data System (ADS)

    Potter, C.; Klooster, S.; Gross, P.; Hiatt, S.; Genovese, V.

    2008-12-01

    The varied topography and micro-climates of northern and central coastal California result in high biodiversity and many different levels of primary production driving regional carbon cycles. Coastal mountains trap moisture from low clouds and fog in summer to supplement rainfall in winter. This creates a favorable micro-environment for coniferous forests, including the southernmost habitat of the coast redwood (Sequoia sempervirens), which grows mainly on lower north-facing slopes in Big Sur. In rain shadows, forests transition to open oak woodland, and then into the more fire-tolerant chaparral and coast scrub. Field sites for our on-going climate change studies on the California northern and central coasts currently include the University of California Santa Cruz Campus Natural Reserve, the US Forest Service Brazil Ranch, and the University of California Big Creek Reserve. We are conducting research at each of these sites to better understand possible impacts of climate change, including: (1) biological and physical capacity of soils to capture carbon and retain plant-essential nutrients; (2) rates of plant-soil water and carbon cycling and energy flow; and (3) recovery mechanisms for disturbances such as invasive weed species, grazing, and wildfire. The NASA-CASA simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate carbon cycling for much of the central coast as far north as Mendocino County. Net primary production (NPP) of all vegetation cover was mapped at 30-meter resolution for selected years by combining MODIS and Landsat images across the region. Results show annual NPP predictions of between 200-400 grams C per square meter for coastal scrub and 800-1200 grams C per square meter for coastal evergreen forests, Net ecosystem fluxes of carbon will be presented for the region based on NASA-CASA modeling and field measurements of soil respiration fluxes.

  9. Evaluating Ecosystem Services Provided by Non-Native Species: An Experimental Test in California Grasslands

    PubMed Central

    Stein, Claudia; Hallett, Lauren M.; Harpole, W. Stanley; Suding, Katharine N.

    2014-01-01

    The concept of ecosystem services the benefits that nature provides to human's society has gained increasing attention over the past decade. Increasing global abiotic and biotic change, including species invasions, is threatening the secure delivery of these ecosystem services. Efficient evaluation methods of ecosystem services are urgently needed to improve our ability to determine management strategies and restoration goals in face of these new emerging ecosystems. Considering a range of multiple ecosystem functions may be a useful way to determine such strategies. We tested this framework experimentally in California grasslands, where large shifts in species composition have occurred since the late 1700's. We compared a suite of ecosystem functions within one historic native and two non-native species assemblages under different grazing intensities to address how different species assemblages vary in provisioning, regulatory and supporting ecosystem services. Forage production was reduced in one non-native assemblage (medusahead). Cultural ecosystem services, such as native species diversity, were inherently lower in both non-native assemblages, whereas most other services were maintained across grazing intensities. All systems provided similar ecosystem services under the highest grazing intensity treatment, which simulated unsustainable grazing intensity. We suggest that applying a more comprehensive ecosystem framework that considers multiple ecosystem services to evaluate new emerging ecosystems is a valuable tool to determine management goals and how to intervene in a changing ecosystem. PMID:25222028

  10. Sea Surface Temperature Influence on Terrestrial Gross Primary Production along the Southern California Current.

    PubMed

    Reimer, Janet J; Vargas, Rodrigo; Rivas, David; Gaxiola-Castro, Gilberto; Hernandez-Ayon, J Martin; Lara-Lara, Ruben

    2015-01-01

    Some land and ocean processes are related through connections (and synoptic-scale teleconnections) to the atmosphere. Synoptic-scale atmospheric (El Nio/Southern Oscillation [ENSO], Pacific Decadal Oscillation [PDO], and North Atlantic Oscillation [NAO]) decadal cycles are known to influence the global terrestrial carbon cycle. Potentially, smaller scale land-ocean connections influenced by coastal upwelling (changes in sea surface temperature) may be important for local-to-regional water-limited ecosystems where plants may benefit from air moisture transported from the ocean to terrestrial ecosystems. Here we use satellite-derived observations to test potential connections between changes in sea surface temperature (SST) in regions with strong coastal upwelling and terrestrial gross primary production (GPP) across the Baja California Peninsula. This region is characterized by an arid/semiarid climate along the southern California Current. We found that SST was correlated with the fraction of photosynthetic active radiation (fPAR; as a proxy for GPP) with lags ranging from 0 to 5 months. In contrast ENSO was not as strongly related with fPAR as SST in these coastal ecosystems. Our results show the importance of local-scale changes in SST during upwelling events, to explain the variability in GPP in coastal, water-limited ecosystems. The response of GPP to SST was spatially-dependent: colder SST in the northern areas increased GPP (likely by influencing fog formation), while warmer SST at the southern areas was associated to higher GPP (as SST is in phase with precipitation patterns). Interannual trends in fPAR are also spatially variable along the Baja California Peninsula with increasing secular trends in subtropical regions, decreasing trends in the most arid region, and no trend in the semi-arid regions. These findings suggest that studies and ecosystem process based models should consider the lateral influence of local-scale ocean processes that could influence coastal ecosystem productivity. PMID:25923109

  11. Sea Surface Temperature Influence on Terrestrial Gross Primary Production along the Southern California Current

    PubMed Central

    Reimer, Janet J.; Vargas, Rodrigo; Rivas, David; Gaxiola-Castro, Gilberto; Hernandez-Ayon, J. Martin; Lara-Lara, Ruben

    2015-01-01

    Some land and ocean processes are related through connections (and synoptic-scale teleconnections) to the atmosphere. Synoptic-scale atmospheric (El Niño/Southern Oscillation [ENSO], Pacific Decadal Oscillation [PDO], and North Atlantic Oscillation [NAO]) decadal cycles are known to influence the global terrestrial carbon cycle. Potentially, smaller scale land-ocean connections influenced by coastal upwelling (changes in sea surface temperature) may be important for local-to-regional water-limited ecosystems where plants may benefit from air moisture transported from the ocean to terrestrial ecosystems. Here we use satellite-derived observations to test potential connections between changes in sea surface temperature (SST) in regions with strong coastal upwelling and terrestrial gross primary production (GPP) across the Baja California Peninsula. This region is characterized by an arid/semiarid climate along the southern California Current. We found that SST was correlated with the fraction of photosynthetic active radiation (fPAR; as a proxy for GPP) with lags ranging from 0 to 5 months. In contrast ENSO was not as strongly related with fPAR as SST in these coastal ecosystems. Our results show the importance of local-scale changes in SST during upwelling events, to explain the variability in GPP in coastal, water-limited ecosystems. The response of GPP to SST was spatially-dependent: colder SST in the northern areas increased GPP (likely by influencing fog formation), while warmer SST at the southern areas was associated to higher GPP (as SST is in phase with precipitation patterns). Interannual trends in fPAR are also spatially variable along the Baja California Peninsula with increasing secular trends in subtropical regions, decreasing trends in the most arid region, and no trend in the semi-arid regions. These findings suggest that studies and ecosystem process based models should consider the lateral influence of local-scale ocean processes that could influence coastal ecosystem productivity. PMID:25923109

  12. Does positioning of the North Pacific Current affect downstream ecosystem productivity?

    NASA Astrophysics Data System (ADS)

    Sydeman, William J.; Thompson, Sarah Ann; Field, John C.; Peterson, William T.; Tanasichuk, Ronald W.; Freeland, Howard J.; Bograd, Steven J.; Rykaczewski, Ryan R.

    2011-06-01

    Fluctuations in the positioning of major ocean currents can influence ecosystem dynamics, but previously the technology has been lacking to make direct observational assessments. Here, we test the hypothesis that positioning of the North Pacific Current (NPC) is related to biological attributes of the central-northern California Current Ecosystem (CCE). To test this hypothesis we use newly available data from the Argo array and compare it with a suite of well-known ecosystem indicators over 6 years, 2002 through 2007. We found increased biomass and productivity when the NPC was shifted poleward, and suggest that positioning influences advective transport of nutrients and perhaps key planktonic organisms from the sub-arctic domain thereby enhancing mid to upper trophic level species. This study is significant because climate change is predicted to cause poleward shifts in the westerlies that drive ocean currents and positioning of large marine gyre systems. Rather than reducing ecosystem productivity, poleward shifts in positioning of the NPC may be beneficial for many species of the central-northern CCE.

  13. PERSISTENCE OF CHLORINATED HYDROCARBON CONTAMINATION IN A CALIFORNIA MARINE ECOSYSTEM

    EPA Science Inventory

    Despite major reductions in the dominant DDT and polychlorinated biphenyls (PCB) input off Los Angeles (California, USA) in the early 1970s, the levels of these pollutants decreased only slightly from 1972 to 1975 both in surficial bottom sediments and in a flatfish bioindicator ...

  14. Climatic impacts on phenology of southern California native ecosystems using MODIS-derived time series

    NASA Astrophysics Data System (ADS)

    Willis, K. S.; Gillespie, T. W.; Okin, G. S.; MacDonald, G. M.

    2014-12-01

    Phenology, the timing of seasonal activities of animals and plants, is a straightforward process used to track the response of ecology to climate change. Remote sensing can be utilized to track these responses and ecosystem functioning in Mediterranean-type ecosystems. This study elucidates these climate-phenology relations in native chaparral- and coastal sage scrub-dominated ecosystems in southern California. Whole ecosystem phenology is monitored for the period 2000-2014 using the Normalized Difference Vegetation Index (NDVI) derived from MODIS MOD13Q1. Changes in phenology are assessed through comparison of the time series with raw data and anomalies of temperature, precipitation, and Palmer Drought Indices (Modified Drought Index and Z Index) data to address the following questions: 1) Which climatic factors have the greatest impact on southern California whole ecosystem phenology? And 2) What are the differences between chaparral- and coastal sage scrub-dominated ecosystems? In addressing these questions, special consideration is given to late 2013/ 2014; a season of exceptional drought. We find that anomalous Palmer Drought Indices show highest correlations with vegetation NDVI. Each vegetation type displays a different response to short-term climate; with chaparral ecosystems having highest correlations with drought indices, and coastal sage scrub correlations highest with discrete precipitation events and temperature. Climate anomalies had little to no correlations with NDVI, indicating that the phenology of these native plants may be highly resilient to short-term changes in climate.

  15. In the Schools: California Treat: Three Days in Five Ecosystems.

    ERIC Educational Resources Information Center

    Rigby, Jennifer A.

    1986-01-01

    Describes a 3-day program sponsored by the Orange County Marine Institute that provides biological, cultural, and historical learning experiences. Discusses the setting and activities of the five ecosystems explored by the students. The Chaparral to Ocean Science Camp includes chaparral, riparian, woodland, intertidal, and pelagic environments.

  16. In the Schools: California Treat: Three Days in Five Ecosystems.

    ERIC Educational Resources Information Center

    Rigby, Jennifer A.

    1986-01-01

    Describes a 3-day program sponsored by the Orange County Marine Institute that provides biological, cultural, and historical learning experiences. Discusses the setting and activities of the five ecosystems explored by the students. The Chaparral to Ocean Science Camp includes chaparral, riparian, woodland, intertidal, and pelagic environments.…

  17. Effects of drought stress on microbial dynamics in seasonally dry California ecosystems

    NASA Astrophysics Data System (ADS)

    Schaeffer, S. M.; Boot, C. M.; Doyle, A.; Clark, J.; Schimel, J. P.

    2008-12-01

    One of the key environmental factors controlling microbial activity is moisture. This water limitation is particularly strong in semi-arid and arid ecosystems such as those found along California's coast and interior range-lands. Cool, wet winters separated by long, dry summers present some the most challenging conditions for microbial survival and growth. Infrequent pulses of precipitation directly control microbial dynamics through soil wet-dry cycles, which in turn control the export of materials and nutrients into streams and groundwater. Recent research suggests that living microbial biomass can increase during the driest, hottest part of the year. We measured dissolved organic carbon and nitrogen (DOC, DON), microbial biomass carbon and nitrogen, inorganic nitrogen (NH4+, NO3-), and nitrification potential from July of 2007 to the present in California semi-arid grasslands. We also monitored inorganic nitrogen concentrations in soil pore water, shallow ground water, and stream water over the same period. Seasonal trends in DOC and DON show that they accumulate over the dry summer, and then decrease with the onset of the winter rains. Microbial biomass carbon showed a similar pattern, being higher in the summer and declining during winter (188.9413.34 and 139.218.45 ?g C g-1 dry soil respectively. However, biomass nitrogen remained unchanged over the same period (11.210.84 and 10.860.74 ?g N g-1 dry soil respectively). Nitrification potentials were lowest during the winter wet season (5.260.40 ?g N d-1 g-1 dry soil) and highest during the dry summer season (8.910.60 ?g N d-1 g-1 dry soil). However, the seasonal patterns in NH4+ and NO3- availability suggest that net nitrification was not substantial until after the winter rains began. It is not currently known whether this increase in biomass represents actual growth of new organisms, or is a result of microbes accumulating internal solutes to avoid drying out. At the landscape-scale, these microbial dynamics control the amount and composition of nutrient export from these ecosystems into groundwater and streams. Long, dry summers allow nutrients to accumulate, and then a single large precipitation event can lead to a large pulse being released. Microbial dynamics in natural ecosystems, such as NO3- production via nitrification, can have important implications for water quality (in the case of NO3-) in urban areas located downstream.

  18. 2013. Wetlands. In: Mooney, H. and Zavaleta, E., editors. Ecosystems of California: A Source Book. Berkeley, CA: University of California Press, p.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This publication is an introduction to wetland ecosystems in California, their geographic distribution, and historical ecology. Hydroclimatology and hydrology are explained as key drivers and patterns of variability in wetland habitats and biological communities. Primary wetland types are describe...

  19. Where the wild things are: Predicting hotspots of seabird aggregations in the California Current System

    USGS Publications Warehouse

    Nur, N.; Jahncke, J.; Herzog, M.P.; Howar, J.; Hyrenbach, K.D.; Zamon, J.E.; Ainley, D.G.; Wiens, J.A.; Morgan, K.; Balance, L.T.; Stralberg, D.

    2011-01-01

    Marine Protected Areas (MPAs) provide an important tool for conservation of marine ecosystems. To be most effective, these areas should be strategically located in a manner that supports ecosystem function. To inform marine spatial planning and support strategic establishment of MPAs within the California Current System, we identified areas predicted to support multispecies aggregations of seabirds ("hotspot????). We developed habitat-association models for 16 species using information from at-sea observations collected over an 11-year period (1997-2008), bathymetric data, and remotely sensed oceanographic data for an area from north of Vancouver Island, Canada, to the USA/Mexico border and seaward 600 km from the coast. This approach enabled us to predict distribution and abundance of seabirds even in areas of few or no surveys. We developed single-species predictive models using a machine-learning algorithm: bagged decision trees. Single-species predictions were then combined to identify potential hotspots of seabird aggregation, using three criteria: (1) overall abundance among species, (2) importance of specific areas ("core area????) to individual species, and (3) predicted persistence of hotspots across years. Model predictions were applied to the entire California Current for four seasons (represented by February, May, July, and October) in each of 11 years. Overall, bathymetric variables were often important predictive variables, whereas oceanographic variables derived from remotely sensed data were generally less important. Predicted hotspots often aligned with currently protected areas (e.g., National Marine Sanctuaries), but we also identified potential hotspots in Northern California/Southern Oregon (from Cape Mendocino to Heceta Bank), Southern California (adjacent to the Channel Islands), and adjacent to Vancouver Island, British Columbia, that are not currently included in protected areas. Prioritization and identification of multispecies hotspots will depend on which group of species is of highest management priority. Modeling hotspots at a broad spatial scale can contribute to MPA site selection, particularly if complemented by fine-scale information for focal areas. ?? 2011 by the Ecological Society of America.

  20. Current California Drought: Impact on Citrus Trees and Potential Mitigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    California is in another cycle of extended drought. The article reviews and discusses likely impact of the current drought on citrus growers and potential mitigation techniques. Citrus physiological responses to water stress is briefly reviewed. The direct impact of drought on citrus is reduced frui...

  1. California Coastal Upwelling Onset Variability: Cross-Shore and Bottom-Up Propagation in the Planktonic Ecosystem

    PubMed Central

    Chenillat, Fanny; Rivière, Pascal; Capet, Xavier; Franks, Peter J. S.; Blanke, Bruno

    2013-01-01

    The variability of the California Current System (CCS) is primarily driven by variability in regional wind forcing. In particular, the timing of the spring transition, i.e., the onset of upwelling-favorable winds, varies considerably in the CCS with changes in the North Pacific Gyre Oscillation. Using a coupled physical-biogeochemical model, this study examines the sensitivity of the ecosystem functioning in the CCS to a lead or lag in the spring transition. An early spring transition results in an increased vertical nutrient flux at the coast, with the largest ecosystem consequences, both in relative amplitude and persistence, hundreds of kilometers offshore and at the highest trophic level of the modeled food web. A budget analysis reveals that the propagation of the perturbation offshore and up the food web is driven by remineralization and grazing/predation involving both large and small plankton species. PMID:23690935

  2. The large-scale summer circulation of the California current

    NASA Technical Reports Server (NTRS)

    Strub, P. Ted; James, Corinne

    1995-01-01

    Satellite data from the Geosat altimeter and the Advanced Very High Resolution Radiometer (AVHRR) are used to show the large-scale structure of the surface circulation of the California Current System in summer. These data show the connection between an equatorward jet and temperature front off Oregon that lies within 100 km of the coast, similar to that first observed in the 1960's and 1970's, and a jet that meanders along the convoluted offshore edge of a temperature front off California, as repeatedly observed in the 1980's.

  3. Plankton dynamics in a cyclonic eddy in the Southern California Current System

    NASA Astrophysics Data System (ADS)

    Chenillat, Fanny; Franks, Peter J. S.; Rivière, Pascal; Capet, Xavier; Grima, Nicolas; Blanke, Bruno

    2015-08-01

    The California Current System is an eastern boundary upwelling system (EBUS) with high biological production along the coast. Oligotrophic offshore waters create cross-shore gradients of biological and physical properties, which are affected by intense mesoscale eddy activity. The influence of eddies on ecosystem dynamics in EBUS is still in debate. To elucidate the mechanisms that influence the dynamics of ecosystems trapped in eddies, and the relative contribution of horizontal and vertical advection in determining local production, we analyze a particular cyclonic eddy using Lagrangian particle-tracking analyses of numerical Eulerian. The eddy formed in a coastal upwelling system; coastal waters trapped in the eddy enabled it to leave the upwelling region with high concentrations of plankton and nutrients. The ecosystem was initially driven mainly by recycling of biological material. As the eddy moved offshore, production in its core was enhanced compared to eddy exterior waters through Ekman pumping of nitrate from below the euphotic zone; this Ekman pumping was particularly effective due to the shallow nitracline in the eddy compared to eddy exterior waters. Both eddy trapping and Ekman pumping helped to isolate and maintain the ecosystem productivity in the eddy core. This study shows the importance of cyclonic eddies for biological production in EBUS: they contribute both to the redistribution of the coastal upwelling ecosystem and are local regions of enhanced new production. Together, these processes impact cross-shore gradients of important biological properties.

  4. Appreciation, Use, and Management of Biodiversity and Ecosystem Services in California's Working Landscapes

    NASA Astrophysics Data System (ADS)

    Plieninger, Tobias; Ferranto, Shasta; Huntsinger, Lynn; Kelly, Maggi; Getz, Christy

    2012-09-01

    "Working landscapes" is the concept of fostering effective ecosystem stewardship and conservation through active human presence and management and integrating livestock, crop, and timber production with the provision of a broad range of ecosystem services at the landscape scale. Based on a statewide survey of private landowners of "working" forests and rangelands in California, we investigated whether owners who are engaged in commercial livestock or timber production appreciate and manage biodiversity and ecosystem services on their land in different ways than purely residential owners. Both specific uses and management practices, as well as underlying attitudes and motivations toward biodiversity and ecosystem services, were assessed. Correlation analysis showed one bundle of ecosystem goods and services (e.g., livestock, timber, crops, and housing) that is supported by some landowners at the community level. Another closely correlated bundle of biodiversity and ecosystem services includes recreation, hunting/fishing, wildlife habitat, and fire prevention. Producers were more likely to ally with the first bundle and residential owners with the second. The survey further confirmed that cultural ecosystem services and quality-of-life aspects are among the primary amenities that motivate forest and rangeland ownership regardless of ownership type. To live near natural beauty was the most important motive for both landowner groups. Producers were much more active in management for habitat improvement and other environmental goals than residential owners. As the number of production-oriented owners decreases, developing strategies for encouraging environment-positive management by all types of landowners is crucial.

  5. Appreciation, use, and management of biodiversity and ecosystem services in California's working landscapes.

    PubMed

    Plieninger, Tobias; Ferranto, Shasta; Huntsinger, Lynn; Kelly, Maggi; Getz, Christy

    2012-09-01

    "Working landscapes" is the concept of fostering effective ecosystem stewardship and conservation through active human presence and management and integrating livestock, crop, and timber production with the provision of a broad range of ecosystem services at the landscape scale. Based on a statewide survey of private landowners of "working" forests and rangelands in California, we investigated whether owners who are engaged in commercial livestock or timber production appreciate and manage biodiversity and ecosystem services on their land in different ways than purely residential owners. Both specific uses and management practices, as well as underlying attitudes and motivations toward biodiversity and ecosystem services, were assessed. Correlation analysis showed one bundle of ecosystem goods and services (e.g., livestock, timber, crops, and housing) that is supported by some landowners at the community level. Another closely correlated bundle of biodiversity and ecosystem services includes recreation, hunting/fishing, wildlife habitat, and fire prevention. Producers were more likely to ally with the first bundle and residential owners with the second. The survey further confirmed that cultural ecosystem services and quality-of-life aspects are among the primary amenities that motivate forest and rangeland ownership regardless of ownership type. To live near natural beauty was the most important motive for both landowner groups. Producers were much more active in management for habitat improvement and other environmental goals than residential owners. As the number of production-oriented owners decreases, developing strategies for encouraging environment-positive management by all types of landowners is crucial. PMID:22767213

  6. Environmental conditions impacting juvenile Chinook salmon growth off central California: An ecosystem model analysis

    NASA Astrophysics Data System (ADS)

    Fiechter, J.; Huff, D. D.; Martin, B. T.; Jackson, D. W.; Edwards, C. A.; Rose, K. A.; Curchitser, E. N.; Hedstrom, K. S.; Lindley, S. T.; Wells, B. K.

    2015-04-01

    A fully coupled ecosystem model is used to identify the effects of environmental conditions and upwelling variability on growth of juvenile Chinook salmon in central California coastal waters. The ecosystem model framework consists of an ocean circulation submodel, a biogeochemical submodel, and an individual-based submodel for salmon. Simulation results indicate that years favorable for juvenile salmon growth off central California are characterized by particularly intense early season upwelling (i.e., March through May), leading to enhanced krill concentrations during summer near the location of ocean entry (i.e., Gulf of the Farallones). Seasonally averaged growth rates in the model are generally consistent with observed values and suggest that juvenile salmon emigrating later in the season (i.e., late May and June) achieve higher weight gains during their first 90 days of ocean residency.

  7. Material properties of zooplankton and nekton from the California current

    NASA Astrophysics Data System (ADS)

    Becker, Kaylyn

    This study measured the material properties of zooplankton, Pacific hake (Merluccius productus), Humboldt squid (Dosidicus gigas), and two species of myctophids (Symbolophorus californiensis and Diaphus theta) collected from the California Current ecosystem. The density contrast (g) was measured for euphausiids, decapods (Sergestes similis), amphipods (Primno macropa, Phronima sp., and Hyperiid spp.), siphonophore bracts, chaetognaths, larval fish, crab megalopae, larval squid, and medusae. Morphometric data (length, width, and height) were collected for these taxa. Density contrasts varied within and between zooplankton taxa. The mean and standard deviation for euphausiid density contrast were 1.059 +/- 0.009. Relationships between zooplankton density contrast and morphometric measurements, geographic location, and environmental conditions were investigated. Site had a significant effect on euphausiid density contrast. Density contrasts of euphausiids collected in the same geographic area approximately 4-10 days apart were significantly higher (p < 0.001). Sound speed contrast (h) was measured for euphausiids and pelagic decapods (S. similis) and it varied between taxa. The mean and standard deviation for euphausiid sound speed were 1.019 +/- 0.009. Euphausiid mass was calculated from density measurements and volume, and a relationship between euphausiid mass and length was produced. We determined that euphausiid from volumes could be accurately estimated two dimensional measurements of animal body shape, and that biomass (or biovolume) could be accurately calculated from digital photographs of animals. Density contrast (g) was measured for zooplankton, pieces of hake flesh, myctophid flesh, and of the following Humboldt squid body parts: mantle, arms, tentacle, braincase, eyes, pen, and beak. The density contrasts varied within and between fish taxa, as well as among squid body parts. Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast (h) was measured for Pacific hake flesh, myctophid flesh, Humboldt squid mantle, and Humboldt squid braincase. Sound speed varied within and between nekton taxa. The material properties reported in this study can be used to improve target strength estimates from acoustic scattering models which would increase the accuracy of biomass estimates from acoustic surveys for these zooplankton and nekton.

  8. Seasonal Trends in Airborne Fungal Spores in Coastal California Ecosystems

    NASA Astrophysics Data System (ADS)

    Morfin, J.; Crandall, S. G.; Gilbert, G. S.

    2014-12-01

    Airborne fungal spores cause disease in plants and animals and may trigger respiratory illnesses in humans. In terrestrial systems, fungal sporulation, germination, and persistence are strongly regulated by local meteorological conditions. However, few studies investigate how microclimate affects the spatio-temporal dynamics of airborne spores. We measured fungal aerospora abundance and microclimate at varying spatial and time scales in coastal California in three habitat-types: coast redwood forest, mixed-evergreen forest, and maritime chaparral. We asked: 1) is there a difference in total airborne spore concentration between habitats, 2) when do we see peak spore counts, and 3) do spore densities correlate with microclimate conditions? Fungal spores were caught from the air with a volumetric vacuum air spore trap during the wet season (January - March) in 2013 and 2014, as well as monthly in 2014. Initial results suggest that mixed-evergreen forests exhibit the highest amounts of spore abundance in both years compared to the other habitats. This may be due to either a higher diversity of host plants in mixed-evergreen forests or a rich leaf litter layer that may harbor a greater abundance of saprotrophic fungi. Based on pilot data, we predict that temperature and to a lesser degree, relative humidity, will be important microclimate predictors for high spore densities. These data are important for understanding when and under what weather conditions we can expect to see high levels of fungal spores in the air; this can be useful information for managers who are interested in treating diseased plants with fungicides.

  9. Land use change and effects on water quality and ecosystem health in the Lake Tahoe basin, Nevada and California

    USGS Publications Warehouse

    Forney, William; Richards, Lora; Adams, Kenneth D.; Minor, Timothy B.; Rowe, Timothy G.; Smith, J. LaRue; Raumann, Christian G.

    2001-01-01

    Human activity in the Lake Tahoe Basin has increased substantially in the past four decades, causing significant impacts on the quality and clarity of the lake's famous deep, clear water. Protection of Lake Tahoe and the surrounding environment has become an important activity in recent years. A variety of agencies, including the Tahoe Regional Planning Agency, Tahoe Research Group of the University of California at Davis, Desert Research Institute of the University and Community College System of Nevada, U.S. Geological Survey (USGS), and a host of State (both Nevada and California) and local agencies have been monitoring and conducting research in the Basin in order to understand how the lake functions and to what extent humans have affected its landscape and ecosystem processes. In spite of all of these activities, there remains a lack of comprehensive land use change data and analysis for the Basin. A project is underway that unites the land cover mapping expertise of the USGS National Mapping Discipline with the hydrologic expertise of the Water Resources Discipline to assess the impacts of urban growth and land use change in the Lake Tahoe Basin. Three activities are planned over the next 3 years: (1) mapping the current and historic state of the land surface, (2) conducting analysis to document patterns, rates, and trends in urbanization, land use change, and ecosystem health, and (3) assessing the causes and consequences of land use change with regard to water quality and ecosystem health. We hypothesize that changes in the extent of urban growth and the corresponding increases in impervious surfaces and decreases in natural vegetation have resulted in severe impacts on ecosystem health and integrity, riparian zones and water quality over time. We are acting on multiple fronts to test this hypothesis through the quantification of landscape disturbances and impacts.

  10. Multi-decadal variations in calcareous holozooplankton in the California Current System: Thecosome pteropods, heteropods, and foraminifera

    NASA Astrophysics Data System (ADS)

    Ohman, Mark D.; Lavaniegos, Bertha E.; Townsend, Annie W.

    2009-09-01

    We examine long-term (1951-2008) variability of three major taxa of calcareous holozooplankton (aragonite-secreting thecosome pteropods and heteropods, and calcite-secreting large planktonic foraminifera) in light of recent interest in the impingement of waters undersaturated with respect to aragonite onto continental shelf depths in the California Current System. We assess interannual variability in springtime abundances of zooplankton sampled in the epipelagic layer, using CalCOFI (California Cooperative Oceanic Fisheries Investigations) zooplankton samples from two regions: Southern California (SC) and Central California (CC). Thecosome pteropods show no evidence of recent declines in abundance in SC or CC waters. In SC, sampling was sufficient to conclude that heteropods and large foraminifera also show no evidence of declines in abundance in recent years. These results do not preclude as-yet undetected changes in vertical distributions or shell morphology, and underscore the importance of sustained in situ measurement programs in order to detect and understand changes to pelagic ecosystems.

  11. Compound-Specific ?15N Amino Acid Measurements in Littoral Mussels in the California Upwelling Ecosystem: A New Approach to Generating Baseline ?15N Isoscapes for Coastal Ecosystems

    PubMed Central

    Vokhshoori, Natasha L.; McCarthy, Matthew D.

    2014-01-01

    We explored ?15N compound-specific amino acid isotope data (CSI-AA) in filter-feeding intertidal mussels (Mytilus californianus) as a new approach to construct integrated isoscapes of coastal primary production. We examined spatial ?15N gradients in the California Upwelling Ecosystem (CUE), determining bulk ?15N values of mussel tissue from 28 sites between Port Orford, Oregon and La Jolla, California, and applying CSI-AA at selected sites to decouple trophic effects from isotopic values at the base of the food web. Bulk ?15N values showed a strong linear trend with latitude, increasing from North to South (from ?7 to ?12, R2?=?0.759). In contrast, CSI-AA trophic position estimates showed no correlation with latitude. The ?15N trend is therefore most consistent with a baseline ?15N gradient, likely due to the mixing of two source waters: low ?15N nitrate from the southward flowing surface California Current, and the northward transport of the California Undercurrent (CUC), with15N-enriched nitrate. This interpretation is strongly supported by a similar linear gradient in ?15N values of phenylalanine (?15NPhe), the best AA proxy for baseline ?15N values. We hypothesize ?15NPhe values in intertidal mussels can approximate annual integrated ?15N values of coastal phytoplankton primary production. We therefore used ?15NPhe values to generate the first compound-specific nitrogen isoscape for the coastal Northeast Pacific, which indicates a remarkably linear gradient in coastal primary production ?15N values. We propose that ?15NPhe isoscapes derived from filter feeders can directly characterize baseline ?15N values across major biochemical provinces, with potential applications for understanding migratory and feeding patterns of top predators, monitoring effects of climate change, and study of paleo- archives. PMID:24887109

  12. Climate, fishing, and fluctuations of sardine and anchovy in the California Current.

    PubMed

    Lindegren, Martin; Checkley, David M; Rouyer, Tristan; MacCall, Alec D; Stenseth, Nils Chr

    2013-08-13

    Since the days of Elton, population cycles have challenged ecologists and resource managers. Although the underlying mechanisms remain debated, theory holds that both density-dependent and density-independent processes shape the dynamics. One striking example is the large-scale fluctuations of sardine and anchovy observed across the major upwelling areas of the world. Despite a long history of research, the causes of these fluctuations remain unresolved and heavily debated, with significant implications for fisheries management. We here model the underlying causes of these fluctuations, using the California Current Ecosystem as a case study, and show that the dynamics, accurately reproduced since A.D. 1661 onward, are explained by interacting density-dependent processes (i.e., through species-specific life-history traits) and climate forcing. Furthermore, we demonstrate how fishing modifies the dynamics and show that the sardine collapse of the 1950s was largely unavoidable given poor recruitment conditions. Our approach provides unique insight into the origin of sardine-anchovy fluctuations and a knowledge base for sustainable fisheries management in the California Current Ecosystem and beyond. PMID:23836661

  13. Climate, fishing, and fluctuations of sardine and anchovy in the California Current

    PubMed Central

    Lindegren, Martin; Checkley, David M.; Rouyer, Tristan; MacCall, Alec D.; Stenseth, Nils Chr.

    2013-01-01

    Since the days of Elton, population cycles have challenged ecologists and resource managers. Although the underlying mechanisms remain debated, theory holds that both density-dependent and density-independent processes shape the dynamics. One striking example is the large-scale fluctuations of sardine and anchovy observed across the major upwelling areas of the world. Despite a long history of research, the causes of these fluctuations remain unresolved and heavily debated, with significant implications for fisheries management. We here model the underlying causes of these fluctuations, using the California Current Ecosystem as a case study, and show that the dynamics, accurately reproduced since A.D. 1661 onward, are explained by interacting density-dependent processes (i.e., through species-specific life-history traits) and climate forcing. Furthermore, we demonstrate how fishing modifies the dynamics and show that the sardine collapse of the 1950s was largely unavoidable given poor recruitment conditions. Our approach provides unique insight into the origin of sardineanchovy fluctuations and a knowledge base for sustainable fisheries management in the California Current Ecosystem and beyond. PMID:23836661

  14. California nearshore processes - ERTS 1. [coastal currents and sediments

    NASA Technical Reports Server (NTRS)

    Steller, D. D.; Pirie, D. M.

    1974-01-01

    The detectability of many nearshore processes from ERTS is made possible due to the suspended sediment present in the coastal waters. From viewing and analyzing the California coastal imagery collected during the last year and a half, the overall current patterns and their changes have become evident. It is now possible to map monthly and seasonal changes that occur throughout the year. The original objectives of detecting currents, sediment transport, estuaries and river discharge have now been expanded to include the use of ERTS information in operational problems of the U.S. Army Corps of Engineers. This incorporates the detected nearshore features into planning and organizing shore protection facilities.

  15. Long-term changes in pelagic tunicates of the California Current

    NASA Astrophysics Data System (ADS)

    Lavaniegos, Bertha E.; Ohman, Mark D.

    2003-08-01

    This study analyzes interannual variability in springtime carbon biomass of pelagic tunicates (salps, doliolids, pyrosomes, and appendicularians) over the period 1951-2002 from CalCOFI zooplankton samples taken in the southern sector of the California Current System. The results provide evidence for ecosystem changes between 1976 and 1977 and perhaps between 1998 and 1999. A cool-phase group of salps ( Salpa maxima, Pegea socia, Cyclosalpa bakeri, and Cyclosalpa affinis) that was present between 1951 and 1976 was nearly undetectable in Southern California waters during the warm phase of the California Current (1977-98). C. bakeri and C. affinis then re-appeared in 2001. A persistent group of salps ( Salpa aspera, Salpa fusiformis, Thalia democratica, Ritteriella picteti, Iasis zonaria) was observed throughout the study period. The cool-phase species tend to be distributed in mid-latitudes, while the distributions of the persistent species extend to equatorial waters. The cool-phase species have been reported to show little evidence of diel vertical migration, while most of the persistent species are reported to be diel migrants. No distinct multi-decadal patterns were observed in the dominant doliolid Dolioletta gegenbauri, but the rarer subtropical doliolid Doliolum denticulatum was present predominantly during the warm phase of the California Current. The recurrence patterns and biogeographic distributions of both salps and doliolids suggest that the warm phase of the California Current was accompanied by at least some intervals of anomalous transport "seeding" organisms from the south. Variations in total pyrosome and total appendicularian carbon biomass are not clearly related to long-term trends in the water column, although the highest pyrosome biomass occurred in earlier decades and appendicularian biomass has increased since 1999. Long-term changes in the biomass of pelagic tunicates appear to be chiefly responsible for the previously documented long-term decline in California Current total zooplankton biomass. The pattern of decline appeared to reverse in 1999, with a shift to cooler temperatures, somewhat reduced thermal stratification, and an increase in biomass of total zooplankton and of pelagic tunicates.

  16. Mechanisms Controlling the Effects of Weather and Climate on California's Ecosystems (Invited)

    NASA Astrophysics Data System (ADS)

    Goulden, M.; Kelly, A. E.; Fellows, A.; Winston, G.

    2010-12-01

    We combined observations and manipulations along topographic gradients in southern and central California to understand how climate controls ecosystem function. California's topography causes large temperature and precipitation gradients as a result of orographic, rain-shadow, atmospheric lapse, and sea breeze effects. These gradients lead to a wide diversity of ecosystem types and provide a natural laboratory for understanding the controls on plant community composition and ecosystem function. Findings include: (1) Natural climate gradients drive large changes in species composition, plant phenology, growing season length, and primary production. The growing season at low, dry, and warm locations is limited by summer drought, resulting in low primary production. The growing season at high, wet, and cold locations is limited by winter cold, resulting in low primary production. The growing season at mid elevation is limited by neither summer drought nor winter cold, resulting in year-round and high primary production. (2) The relative importance of plant species within a community shifts rapidly in response to changes in water input, caused by either natural variability or experimental manipulation. Species that are intolerant of drier conditions decline rapidly with reduced water input, and may disappear locally; species that are tolerant of drier conditions increase rapidly in extent. (3) Inward plant migration, and the establishment of new species at a location, is a comparatively slow process. The initial phases of climate change will likely reshuffle the importance of existing species within the community, resulting in only modest changes in ecosystem function but possibly extirpating species that are intolerant of warmer and drier conditions, and reducing biodiversity. These declines in biodiversity and delays in species immigration may ultimately limit the ability of ecosystems to respond to subsequent interannual and decadal variations in weather, and to adjust to more extreme changes in climate.

  17. Chloroform, carbon tetrachloride and methyl chloroform fluxes in southern California ecosystems

    NASA Astrophysics Data System (ADS)

    Rhew, Robert C.; Miller, Benjamin R.; Weiss, Ray F.

    Chloroform (CHCl 3), carbon tetrachloride (CCl 4), and methyl chloroform (CH 3CCl 3) are important carriers of chlorine to the stratosphere and account for an estimated 15% of the total organic chlorine in the troposphere, roughly equivalent to chlorine load due to methyl chloride (CH 3Cl). The tropospheric burden of chlorine has declined since 1994, largely due to the restriction of CH 3CCl 3 and CCl 4 use as specified by the Montreal Protocol. However, few field studies have been conducted on the terrestrial-atmosphere exchange of these chlorinated hydrocarbons, leading to uncertainties about the natural cycling of these trace gases. This work shows the results of 75 flux measurements conducted in a variety of southern California ecosystems, including coast sagebrush, chamise chaparral, creosote bush scrub, shoreline, and coastal salt marsh. We find no evidence of a significant soil sink in these ecosystems but rather a small net source of CHCl 3 and possibly CCl 4.

  18. Effects of selenium supplementation in cattle on aquatic ecosystems in northern California

    SciTech Connect

    Norman, B.; Nader, G.; Oliver, M.; Delmas, R.; Drake, D.; George, H. )

    1992-09-15

    The potential impact on aquatic ecosystems of supplementing the diets of beef cattle with selenium (Se) was studied on 4 northern California ranches. All study sites included an area of concentrated use by cattle that had diets supplemented with Se. In each case, a stream flowed through the site and provided a control sampling area upstream and a treated sampling area downstream. Specimens of water, sediment, algae, aquatic plants, aquatic invertebrates, and fish were analyzed fluorometrically for total Se content. Significant differences in Se concentration were not found between specimens from upstream control areas and those from downstream areas subjected to use by Se-treated cattle. Evidence was not found that Se supplementation in cattle at maximal permitted concentrations caused Se accumulation in associated aquatic ecosystems.

  19. Multivariate ocean-climate indicators (MOCI) for the central California Current: Environmental change, 1990-2010

    NASA Astrophysics Data System (ADS)

    Sydeman, William J.; Thompson, Sarah Ann; Garca-Reyes, Marisol; Kahru, Mati; Peterson, William T.; Largier, John L.

    2014-01-01

    Temporal environmental variability may confound interpretations of management actions, such as reduced fisheries mortality when Marine Protected Areas are implemented. To aid in the evaluation of recent ecosystem protection decisions in central-northern California, we designed and implemented multivariate ocean-climate indicators (MOCI) of environmental variability. To assess the validity of the MOCI, we evaluated interannual and longer-term variability in relation to previously recognized environmental variability in the region, and correlated MOCI to a suite of biological indicators including proxies for lower- (phytoplankton, copepods, krill), and upper-level (seabirds) taxa. To develop the MOCI, we selected, compiled, and synthesized 14 well-known atmospheric and oceanographic indicators of large-scale and regional processes (transport and upwelling), as well as local atmospheric and oceanic response variables such as wind stress, sea surface temperature, and salinity. We derived seasonally-stratified MOCI using principal component analysis. Over the 21-year study period (1990-2010), the ENSO cycle weakened while extra-tropical influences increased with a strengthening of the North Pacific Gyre Oscillation (NPGO) and cooling of the Pacific Decadal Oscillation (PDO). Correspondingly, the Northern Oscillation Index (NOI) strengthened, leading to enhanced upwelling-favorable wind stress and cooling of air and ocean surface temperatures. The seasonal MOCI related well to subarctic copepod biomass and seabird productivity, but poorly to chlorophyll-a concentration and krill abundance. Our results support a hypothesis of enhanced sub-arctic influence (transport from the north) and upwelling intensification in north-central California over the past two decades. Such environmental conditions may favor population growth for species with sub-arctic zoogeographic affinities within the central-northern California Current coastal ecosystem.

  20. Seasonality of the transitional region of the California Current System off Baja California

    NASA Astrophysics Data System (ADS)

    Durazo, Reginaldo

    2015-02-01

    Hydrographic data collected over the period 1997-2013 are analyzed to investigate the seasonality of hydrographic features and associated geostrophic flows off the Baja California peninsula. The upper ocean in the region was found to be homogeneous in winter and spring but subdivided into two regions in the summer and autumn. In the first case, the system typically shows relatively low-temperature and salinity waters, which give it a subarctic character. In the second, only the region north of Punta Eugenia (28N) maintains subarctic characteristics, while the southern region receives an inflow of tropical and subtropical waters that results from the weakening of northwesterly winds, which allows the poleward advection of surface waters. Also during this period, a positive wind stress curl promotes the zonal advection of North Pacific's eastern edge waters into the coast and to the north as a surface coastal flow. Average seasonal patterns of geostrophic flow at 200 dbar revealed that the differentiation into provinces is also evident at that depth, with two clearly defined cyclonic structures in summer and autumn, both separated at the latitude of Punta Eugenia. The analyses conducted also showed a clear continuity of the California undercurrent along the shelf break, with more diffuse currents in the winter. Poleward flows were observed throughout the water column, especially in summer and autumn, although the origin of the surface flow does not necessarily involve a surfacing of the California Undercurrent.

  1. Low-frequency Eddy Dynamics in the California Current System

    NASA Astrophysics Data System (ADS)

    Davis, A. M.; Di Lorenzo, E.

    2012-12-01

    The goal of this study is to diagnose the dynamics controlling low-frequency modulations of the eddy statistics in the California Current. Using an ensemble of high resolution ocean model hindcasts from 1950-2010 we separate the intrinsic and deterministic fraction of eddy variability in the southern (28.5 N to 34.5 N) and northern (34.5 N to 50 N) California Current System. We find that both cyclonic and anticyclonic eddy counts exhibit low-frequency fluctuations and a strong seasonal cycle, They also evince a "length cascade-" and a transition of enstrophy from shorter to longer length scales. In the southern region, ~50% of the low-frequency eddy variance is deterministic and modulated by coastally trapped waves of southern origin and changes in the seasonal wind stress curl gradient. In the northern region, coastally trapped waves play a minor role and virtually all of the deterministic low-frequency eddy variability is forced by large-scale changes in the wind stress curl gradient. Understanding and quantifying the external forcings of eddy variability allows us to better estimate how climate variability & change impact the mesoscale transport dynamics.

  2. Accumulation of current-use and organochlorine pesticides in crab embryos from Northern California, USA

    USGS Publications Warehouse

    Smalling, Kelly L.; Morgan, Steven; Kuivila, Kathryn K.

    2010-01-01

    Invertebrates have long been used as resident sentinels for assessing ecosystem health and productivity. The shore crabs, Hemigrapsus oregonensis and Pachygrapsus crassipes, are abundant in estuaries and beaches throughout northern California, USA and have been used as indicators of habitat conditions in several salt marshes. The overall objectives of the present study were to conduct a lab-based study to test the accumulation of current-use pesticides, validate the analytical method and to analyze field-collected crabs for a suite of 74 current-use and legacy pesticides. A simple laboratory uptake study was designed to determine if embryos could bioconcentrate the herbicide molinate over a 7-d period. At the end of the experiment, embryos were removed from the crabs and analyzed by gas chromatography/mass spectrometry. Although relatively hydrophilic (log KOW of 2.9), molinate did accumulate with an estimated bioconcentration factor (log BCF) of approximately 2.5. Following method validation, embryos were collected from two different Northern California salt marshes and analyzed. In field-collected embryos 18 current-use and eight organochlorine pesticides were detected including synthetic pyrethroids and organophosphate insecticides, as well as DDT and its degradates. Lipid-normalized concentrations of the pesticides detected in the field-collected crab embryos ranged from 0.1 to 4 ppm. Pesticide concentrations and profiles in crab embryos were site specific and could be correlated to differences in land-use practices. These preliminary results indicate that embryos are an effective sink for organic contaminants in the environment and have the potential to be good indicators of ecosystem health, especially when contaminant body burden analyses are paired with reproductive impairment assays.

  3. SAFRR Tsunami Scenario. Preparedness and Resilience for California's ecosystems, natural resources, and the communities that depend on them

    NASA Astrophysics Data System (ADS)

    Brosnan, D. M.

    2013-12-01

    The SAFRR Tsunami Scenario models a plausible 9.1MP earthquake occuring off the Alaskan coast, that generates a tsunami forecast to strike California between 4-6 hour after the event. California's diverse ecosystems, natural resources, and sensitive species will be significantly affected. Although often overlooked in disaster risk reduction, damage to ecosystems and natural resources during hazards including tsunamis, has often resulted in serious impacts to natural systems and on humans who depend on them. SAFRR tsunami scenario forecasts of wave amplitude, water velocity and inundation and overlain on GIS maps were analyzed to identify plausible impacts on California's ecosystems including beaches, marshes, nearshore subtidal habitats, as well as parks and reserves. The effect on natural resources including fisheries was evaluated. Recovery times and consequences were analyzed. The results illustrate the value and vulnerability of these resources and guidelines for preparation and mitigation are discussed.

  4. The North Pacific High and wintertime pre-conditioning of California current productivity

    NASA Astrophysics Data System (ADS)

    Schroeder, Isaac D.; Black, Bryan A.; Sydeman, William J.; Bograd, Steven J.; Hazen, Elliott L.; Santora, Jarrod A.; Wells, Brian K.

    2013-02-01

    Abstract Variations in large-scale atmospheric forcing influence upwelling dynamics and <span class="hlt">ecosystem</span> productivity in the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS). In this paper, we characterize interannual variability of the North Pacific High over 40 years and investigate how variation in its amplitude and position affect upwelling and biology. We develop a winter upwelling "pre-conditioning" index and demonstrate its utility to understanding biological processes. Variation in the winter NPH can be well described by its areal extent and maximum pressure, which in turn is predictive of winter upwelling. Our winter pre-conditioning index explained 64% of the variation in biological responses (fish and seabirds). Understanding characteristics of the NPH in winter is therefore critical to predicting biological responses in the CCS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3153035','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3153035"><span id="translatedtitle">Differential Distributions of Synechococcus Subgroups Across the <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Paerl, Ryan W.; Johnson, Kenneth S.; Welsh, Rory M.; Worden, Alexandra Z.; Chavez, Francisco P.; Zehr, Jonathan P.</p> <p>2011-01-01</p> <p>Synechococcus is an abundant marine cyanobacterial genus composed of different populations that vary physiologically. Synechococcus narB gene sequences (encoding for nitrate reductase in cyanobacteria) obtained previously from isolates and the environment (e.g., North Pacific Gyre Station ALOHA, Hawaii or Monterey Bay, CA, USA) were used to develop quantitative PCR (qPCR) assays. These qPCR assays were used to quantify populations from specific narB phylogenetic clades across the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS), a region composed of dynamic zones between a coastal-upwelling zone and the oligotrophic Pacific Ocean. Targeted populations (narB subgroups) had different biogeographic patterns across the CCS, which appear to be driven by environmental conditions. Subgroups C_C1, D_C1, and D_C2 were abundant in coastal-upwelling to coastal-transition zone waters with relatively high to intermediate ammonium, nitrate, and chl. a concentrations. Subgroups A_C1 and F_C1 were most abundant in coastal-transition zone waters with intermediate nutrient concentrations. E_O1 and G_O1 were most abundant at different depths of oligotrophic open-ocean waters (either in the upper mixed layer or just below). E_O1, A_C1, and F_C1 distributions differed from other narB subgroups and likely possess unique ecologies enabling them to be most abundant in waters between coastal and open-ocean waters. Different CCS zones possessed distinct Synechococcus communities. Core <span class="hlt">California</span> <span class="hlt">current</span> water possessed low numbers of narB subgroups relative to counted Synechococcus cells, and coastal-transition waters contained high abundances of Synechococcus cells and total number of narB subgroups. The presented biogeographic data provides insight on the distributions and ecologies of Synechococcus present in an eastern boundary <span class="hlt">current</span> system. PMID:21833315</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70036241','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70036241"><span id="translatedtitle">Estimating <span class="hlt">California</span> <span class="hlt">ecosystem</span> carbon change using process model and land cover disturbance data: 1951-2000</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Liu, J.; Vogelmann, J.E.; Zhu, Z.; Key, C.H.; Sleeter, B.M.; Price, D.T.; Chen, J.M.; Cochrane, M.A.; Eidenshink, J.C.; Howard, S.M.; Bliss, N.B.; Jiang, H.</p> <p>2011-01-01</p> <p>Land use change, natural disturbance, and climate change directly alter <span class="hlt">ecosystem</span> productivity and carbon stock level. The estimation of <span class="hlt">ecosystem</span> carbon dynamics depends on the quality of land cover change data and the effectiveness of the <span class="hlt">ecosystem</span> models that represent the vegetation growth processes and disturbance effects. We used the Integrated Biosphere Simulator (IBIS) and a set of 30- to 60-m resolution fire and land cover change data to examine the carbon changes of <span class="hlt">California</span>'s forests, shrublands, and grasslands. Simulation results indicate that during 1951-2000, the net primary productivity (NPP) increased by 7%, from 72.2 to 77.1TgCyr-1 (1 teragram=1012g), mainly due to CO2 fertilization, since the climate hardly changed during this period. Similarly, heterotrophic respiration increased by 5%, from 69.4 to 73.1TgCyr-1, mainly due to increased forest soil carbon and temperature. Net <span class="hlt">ecosystem</span> production (NEP) was highly variable in the 50-year period but on average equalled 3.0TgCyr-1 (total of 149TgC). As with NEP, the net biome production (NBP) was also highly variable but averaged -0.55TgCyr-1 (total of -27.3TgC) because NBP in the 1980s was very low (-5.34TgCyr-1). During the study period, a total of 126Tg carbon were removed by logging and land use change, and 50Tg carbon were directly removed by wildland fires. For carbon pools, the estimated total living upper canopy (tree) biomass decreased from 928 to 834TgC, and the understory (including shrub and grass) biomass increased from 59 to 63TgC. Soil carbon and dead biomass carbon increased from 1136 to 1197TgC. Our analyses suggest that both natural and human processes have significant influence on the carbon change in <span class="hlt">California</span>. During 1951-2000, climate interannual variability was the key driving force for the large interannual changes of <span class="hlt">ecosystem</span> carbon source and sink at the state level, while logging and fire were the dominant driving forces for carbon balances in several specific ecoregions. From a long-term perspective, CO2 fertilization plays a key role in maintaining higher NPP. However, our study shows that the increase in C sequestration by CO2 fertilization is largely offset by logging/land use change and wildland fires. ?? 2011 Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16728644','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16728644"><span id="translatedtitle">Strong top-down control in southern <span class="hlt">California</span> kelp forest <span class="hlt">ecosystems</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Halpern, Benjamin S; Cottenie, Karl; Broitman, Bernardo R</p> <p>2006-05-26</p> <p>Global-scale changes in anthropogenic nutrient input into marine <span class="hlt">ecosystems</span> via terrestrial runoff, coupled with widespread predator removal via fishing, have created greater urgency for understanding the relative role of top-down versus bottom-up control of food web dynamics. Yet recent large-scale studies of community regulation in marine <span class="hlt">ecosystems</span> have shown dramatically different results that leave this issue largely unresolved. We combined a multiyear, large-scale data set of species abundances for 46 species in kelp forests from the <span class="hlt">California</span> Channel Islands with satellite-derived primary production and found that top-down control explains 7- to 10-fold more of the variance in abundance of bottom and mid-trophic levels than does bottom-up control. This top-down control was propagated via a variety of species-level direct and indirect responses to predator abundance. Management of top-down influences such as fishing may be more important in coastal marine <span class="hlt">ecosystems</span>, particularly in kelp forest systems, than is commonly thought. PMID:16728644</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70019896','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70019896"><span id="translatedtitle">The <span class="hlt">California</span> <span class="hlt">current</span> of the last glacial maximum: reconstruction at 42°N based on multiple proxies</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ortiz, Joseph D.; Mix, Alan C.; Hostetler, Steven W.; Kashgarian, Michaele</p> <p>1997-01-01</p> <p>Multiple paleoceanographic proxies in a zonal transect across the <span class="hlt">California</span> <span class="hlt">Current</span> near 42°N record modern and last glacial maximum (LGM) thermal and nutrient gradients. The offshore thermal gradient, derived from foraminiferal species assemblages and oxygen isotope data, was similar at the LGM to that at present (warmer offshore), but average temperatures were 3.3° ±1.5°C colder. Observed gradients require that the sites remained under the southward flow of the <span class="hlt">California</span> <span class="hlt">Current</span>, and thus that the polar front remained north of 42°N during the LGM. Carbon isotopic and foraminiferal flux data suggests enhanced nutrients and productivity of foraminfera in the northern <span class="hlt">California</span> <span class="hlt">Current</span> up to 650 km offshore. In contrast, marine organic carbon and coastal diatom burial rates decreased during the LGM. These seemingly contradictory results are reconciled by model simulations of the LGM wind- field, which suggest that wind stress curl at 42°N (and thus open-ocean upwelling) increased, while offshore Ekman transport (and thus coastal upwelling) decreased during the last ice age. The <span class="hlt">ecosystem</span> of the northern <span class="hlt">California</span> <span class="hlt">Current</span> during the LGM approximated that of the modern Gulf of Alaska. Cooling and production in this region was thus driven by stronger open-ocean upwelling and/or southward flow of high-latitude water masses, rather than by coastal upwelling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMNH14A..03A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMNH14A..03A"><span id="translatedtitle">Observed and Modeled Tsunami <span class="hlt">Currents</span> on <span class="hlt">California</span>'s North Coast</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Admire, A. R.; Dengler, L.; Crawford, G. B.; uslu, B. U.; Montoya, J.; Wilson, R. I.</p> <p>2011-12-01</p> <p>In 2009, a pilot project was implemented in Humboldt Bay, near Eureka, <span class="hlt">California</span> to measure the <span class="hlt">currents</span> produced by tsunamis. This area is susceptible to both near- and far-field tsunamis and has a historic record of damaging events. Crescent City Harbor, located about 100km north of Humboldt Bay, suffered 20 million in damages from strong <span class="hlt">currents</span> produced by the 2006 Kuril Islands tsunami and an additional 16 million from the 2011 Tohoku-oki (Japan) tsunami. We deployed a Nortek Aquadopp 600kHz 2D Acoustic Doppler <span class="hlt">Current</span> Profiler (ADCP) with a one-minute sampling interval in Humboldt Bay, near the NOAA tide gauge site. The instrument recorded the tsunami produced by the Mw 8.8 Chilean earthquake on February 27, 2010 as well as the Mw 9.0 Japanese earthquake on March 11, 2011. <span class="hlt">Currents</span> from the 2010 tsunami persisted in Humboldt Bay for at least 30hrs with a peak <span class="hlt">current</span> amplitude of 0.3m/s. The 2011 tsunami signal lasted for over 86hrs with a peak amplitude of 1.2m/s. Strongest <span class="hlt">currents</span> corresponded to the maximum change in water level as recorded on the NOAA tide gauge, about 90min after the initial wave arrival. Tsunami <span class="hlt">currents</span> associated with ebb tides (tidal <span class="hlt">currents</span> flowing out of the bay) were about 25% larger than <span class="hlt">currents</span> associated with flood tides. No damage was observed in Humboldt Bay for either event; the 2011 tsunami pulled one boat away from its moorings at the marina about six kilometers away from the instrument site. Although we have no instrument in Crescent City, we were able to estimate <span class="hlt">currents</span> for the first three and a half hours of the Japan tsunami using security camera video footage from the Harbor Master building across from the entrance to the boat basin, about 70m away from the NOAA tide gauge site. Most of the damage occurred within this time window. The strongest <span class="hlt">currents</span> reached 4.5m/s and six cycles exceeded 4m/s in the three and a half hours of data. We used the MOST (Method of Splitting Tsunamis) model to compare measured <span class="hlt">currents</span> to numerical predictions. MOST does a reasonably good job of predicting peak amplitudes for the 2010 and 2011 events in Humboldt Bay and the 2011 tsunami in Crescent City. For Humboldt Bay, the model does a good job of replicating the first four hours of the signal although the ebb <span class="hlt">currents</span> are slightly underestimated. The model predictions break down for the later part of the signal. This project shows that ADCPs can effectively record tsunami <span class="hlt">currents</span> for small to moderate events. Data from this project will be used to validate and/or calibrate MOST so that realistic tsunami <span class="hlt">current</span> hazard maps can be generated for <span class="hlt">California</span> for use by harbor managers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21329349','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21329349"><span id="translatedtitle">Anthropogenic <span class="hlt">currents</span> and shoreline water quality in Avalon Bay, <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ho, Lin C; Litton, Rachel M; Grant, Stanley B</p> <p>2011-03-15</p> <p>Shoreline concentrations of fecal indicator bacteria (FIB) and fecal indicator viruses (FIV) in Avalon Bay (Catalina Island, <span class="hlt">California</span>) display a marked diurnal pattern (higher at night and lower during the day) previously attributed to the tidal flux of sewage-contaminated groundwater and the tidal washing of contaminated sediments, coupled with light and dark die-off of FIB and FIV (Boehm, et al., Environ. Sci. Technol. 2009, 43, 8046-8052). In this paper we document the existence of strong (peak velocities between 20 to 40 cm/s) transient <span class="hlt">currents</span> in the nearshore waters of Avalon Bay that occur between 07:00 and 20:00 each day. These <span class="hlt">currents</span>, which have a significant onshore component, are generated by anthropogenic activities in the Bay, including prop wash from local boat traffic and the docking practices of large passenger ferries. A budget analysis carried out on simultaneous measurements of FIB at two cross-shore locations indicates that anthropogenic <span class="hlt">currents</span> contribute to the diurnal cycling of FIB concentrations along the shoreline, by transporting relatively unpolluted water from offshore toward the beach. The data and analysis presented in this paper support the idea that anthropogenic <span class="hlt">currents</span> represent a significant, and previously overlooked, source of variability in shoreline water quality. PMID:21329349</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DSRII.112...31D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DSRII.112...31D"><span id="translatedtitle">Interannual forcing mechanisms of <span class="hlt">California</span> <span class="hlt">Current</span> transports II: Mesoscale eddies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davis, Andrew; Di Lorenzo, Emanuele</p> <p>2015-02-01</p> <p>Mesoscale eddies exert dominant control of cross-shelf exchanges, yet the forcing dynamics underlying their interannual and decadal variability remain uncertain. Using an ensemble of high-resolution ocean model hindcasts of the central and eastern North Pacific from 1950 to 2010 we diagnose the forcing mechanisms of low-frequency eddy variability in the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS). We quantify eddy activity by developing eddy counts based on closed contours of the Okubo-Weiss parameter and find that the spatial and temporal features of model-derived counts largely reproduce the short AVISO observational record. Comparison of model ensemble members allows us to separate the intrinsic and deterministic fractions of eddy variability in the northern CCS (34.5-50N) and in the southern CCS (28.5-34.5N). In the North, a large fraction of low-frequency eddy variability (30% anticyclones, 20% cyclones) is deterministic and shared with satellite observations. We develop a diagnostic model based on indices of the large-scale barotropic and baroclinic states of the CCS which recovers this deterministic variance. This model also strongly correlates with local atmospheric forcing. In contrast to the North, Southern CCS eddy counts exhibit very little deterministic variance, and eddy formation closely resembles a red-noise process. This new understanding of the external forcings of eddy variability allows us to better estimate how climate variability and change impact mesoscale transports in the <span class="hlt">California</span> <span class="hlt">Current</span>. The skill of our diagnostic model and its close association with local wind stress curl indicate that local atmospheric forcing is the dominant driver of eddy activity on interannual and decadal time scales north of pt. conception (~33N).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.H24F..08B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H24F..08B"><span id="translatedtitle">Identifying Key Vulnerabilities in <span class="hlt">Current</span> Management of <span class="hlt">California</span> Central Valley for the <span class="hlt">California</span> Water Plan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bloom, E.; Groves, D.; Joyce, B. A.; Juricich, R.</p> <p>2012-12-01</p> <p>The <span class="hlt">California</span> Department of Water Resources (DWR), for its 2013 Update of the <span class="hlt">California</span> Water Plan (CWP), is building new analytic capabilities for developing and evaluating regional and state-wide water management strategies. These strategies are intended to address growing and diverse water needs coupled with uncertain future hydrologic conditions and available supplies. Recognizing the significant uncertainty about future water management conditions, DWR is utilizing new robust decision methods to identify robust and adaptive water management strategies. This talk will describe a recently completed application of Robust Decision Making (RDM) for long-term water planning as part of the 2013 CWP Update. This analysis utilizes a new hydrologic / water management model of the Sacramento River, San Joaquin River, and Tulare hydrologic regions, running the model under hundreds of potential futures. These futures consider potential variation in demographic growth, land-use patterns, drought length and timing, and other climate factors from projections generated by downscaled global circulation models. Cluster-finding "scenario discovery" algorithms, applied to the resulting database of simulation model results, identify the key characteristics of future conditions where <span class="hlt">current</span> management fails to meet a wide range of policy objectives. These "vulnerabilities" provide the foundation for developing more robust and adaptive response packages and the considering tradeoffs between such response packages. This analysis will provide guidance for considering response packages to meet the challenges posed by future conditions in the <span class="hlt">California</span> Central Valley and provides a widely applicable new approach for making water management plans more cognizant and responsive to a wide range of uncertainties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PrOce..91..397S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PrOce..91..397S"><span id="translatedtitle">Mesoscale structure and oceanographic determinants of krill hotspots in the <span class="hlt">California</span> <span class="hlt">Current</span>: Implications for trophic transfer and conservation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Santora, Jarrod A.; Sydeman, William J.; Schroeder, Isaac D.; Wells, Brian K.; Field, John C.</p> <p>2011-12-01</p> <p>Krill (crustaceans of the family Euphausiacea) comprise an important prey field for vast array of fish, birds, and marine mammals in the <span class="hlt">California</span> <span class="hlt">Current</span> and other large marine <span class="hlt">ecosystems</span> globally. In this study, we test the hypothesis that mesoscale spatial organization of krill is related to oceanographic conditions associated with coastal upwelling. To test this, we compiled a climatology of krill distributions based on hydroacoustic surveys off <span class="hlt">California</span> in May-June each year between 2000 and 2009 (missing 2007). Approximately 53,000 km of ocean habitat was sampled, resulting in a comprehensive geo-spatial data set from the Southern <span class="hlt">California</span> Bight to Cape Mendocino. We determined the location and characteristics of eight definite and two probable krill “hotspots” of abundance. Directional-dependence analysis revealed that krill hotspots were oriented in a northwest-southeast (135°) direction, corresponding to the anisotropy of the 200-2000 m isobath. Krill hotspots were disassociated (inversely correlated) with three upwelling centers, Point Arena, Point Sur, and Point Conception, suggesting that krill may avoid locations of strong offshore transport or aggregate downstream from these locations. While <span class="hlt">current</span> fisheries management considers the entire coast out to the 2000 m isobath critical habitat for krill in this <span class="hlt">ecosystem</span>, we establish here smaller scale structuring of this critical mid-trophic level prey resource. Identifying mesoscale krill hotspots and their oceanographic determinants is significant as these smaller <span class="hlt">ecosystem</span> divisions may warrant protection to ensure key <span class="hlt">ecosystem</span> functions (i.e., trophic transfer) and resilience. Furthermore, delineating and quantifying krill hotspots may be important for conservation of krill-predators in this system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/of/2015/1068/pdf/ofr2015-1068_sheet10.pdf','USGSPUBS'); return false;" href="http://pubs.usgs.gov/of/2015/1068/pdf/ofr2015-1068_sheet10.pdf"><span id="translatedtitle"><span class="hlt">California</span> State Waters Map Series: offshore of San Francisco, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cochrane, Guy R.; Johnson, Samuel Y.; Dartnell, Peter; Greene, H. Gary; Erdey, Mercedes D.; Golden, Nadine E.; Hartwell, Stephen R.; Endris, Charles A.; Manson, Michael W.; Sliter, Ray W.; Kvitek, Rikk G.; Watt, Janet Tilden; Ross, Stephanie L.; Bruns, Terry R.</p> <p>2015-01-01</p> <p>Circulation over the continental shelf in the Offshore of San Francisco map area is dominated by the southward-flowing <span class="hlt">California</span> <span class="hlt">Current</span>, an eastern limb of the North Pacific Gyre that flows from Oregon to Baja <span class="hlt">California</span>. At its midpoint offshore of central <span class="hlt">California</span>, the <span class="hlt">California</span> <span class="hlt">Current</span> transports subarctic surface waters southeastward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the <span class="hlt">California</span> <span class="hlt">Current</span>, generate coastal upwelling. Ocean temperatures offshore of central <span class="hlt">California</span> have increased over the past 50 years, driving an <span class="hlt">ecosystem</span> shift from the productive subarctic regime towards a depopulated subtropical environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PrOce.106..154S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PrOce.106..154S"><span id="translatedtitle">Spatial ecology of krill, micronekton and top predators in the central <span class="hlt">California</span> <span class="hlt">Current</span>: Implications for defining ecologically important areas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Santora, Jarrod A.; Field, John C.; Schroeder, Isaac D.; Sakuma, Keith M.; Wells, Brian K.; Sydeman, William J.</p> <p>2012-11-01</p> <p>Marine spatial planning and <span class="hlt">ecosystem</span> models that aim to predict and protect fisheries and wildlife benefit greatly from syntheses of empirical information on physical and biological partitioning of marine <span class="hlt">ecosystems</span>. Here, we develop spatially-explicit oceanographic and ecological descriptions of the central <span class="hlt">California</span> <span class="hlt">Current</span> region. To partition this region, we integrate data from 20 years of shipboard surveys with satellite remote-sensing to characterize local seascapes of ecological significance, focusing on krill, other micronekton taxa, and top predators (seabirds and marine mammals). Specifically, we investigate if micronekton and predator assemblages co-vary spatially with mesoscale oceanographic conditions. The first principal component of environmental and micronekton seascapes indicates significant coupling between physics, primary productivity, and secondary and tertiary marine consumers. Subsequent principal components indicate latitudinal variability in niche-community space due to varying habitat characteristics between Monterey Bay (deep submarine canyon system) and the Gulf of the Farallones (extensive continental shelf), even though both of these sub-regions are located downstream from upwelling centers. Overall, we identified five ecologically important areas based on spatial integration of environmental and biotic features. These areas, characterized by proximity to upwelling centers, shallow pycnoclines, and high chlorophyll-a and krill concentrations, are potential areas of elevated trophic focusing for specific epipelagic and mesopelagic communities. This synthesis will benefit <span class="hlt">ecosystem</span>-based management approaches for the central <span class="hlt">California</span> <span class="hlt">Current</span>, a region long-impacted by anthropogenic factors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.5950J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.5950J"><span id="translatedtitle">Sensitivity of the <span class="hlt">California</span> <span class="hlt">Current</span> nutrient supply to wind, heat, and remote ocean forcing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jacox, Michael G.; Bograd, Steven J.; Hazen, Elliott L.; Fiechter, Jerome</p> <p>2015-07-01</p> <p>A regional ocean model is used to evaluate the roles of wind, surface heat flux, and basin-scale climate variability in regulating the upwelled nitrate supply in the <span class="hlt">California</span> <span class="hlt">Current</span>. A strong positive trend in nitrate flux from 1980 to 2010 was driven almost entirely by enhanced equatorward winds, negating a weak negative trend associated with increased surface heat flux. Increased upwelling and nitrate flux are consistent with cooler surface temperatures and higher phytoplankton concentrations observed over the same period. Changes in remote ocean forcing, resulting primarily from basin-scale climate variability (e.g., El Nio-Southern Oscillation and Pacific Decadal Oscillation), drive considerable interannual fluctuations and may dominate the <span class="hlt">ecosystem</span> response on interannual to decadal time scales. However, comparison with previously published findings suggests that local wind intensification persists through changing basin-scale climate regimes. Understanding the different time scales of variability in forcing mechanisms, and their interactions with each other, is necessary to distinguish transient <span class="hlt">ecosystem</span> impacts from secular trends.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMS...146..121H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMS...146..121H"><span id="translatedtitle">Diet variability of forage fishes in the Northern <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hill, Andrew D.; Daly, Elizabeth A.; Brodeur, Richard D.</p> <p>2015-06-01</p> <p>As fisheries management shifts to an <span class="hlt">ecosystem</span>-based approach, understanding energy pathways and trophic relationships in the Northern <span class="hlt">California</span> <span class="hlt">Current</span> (NCC) will become increasingly important for predictive modeling and understanding <span class="hlt">ecosystem</span> response to changing ocean conditions. In the NCC, pelagic forage fishes are a critical link between seasonal and interannual variation in primary production and upper trophic groups. We compared diets among dominant forage fish (sardines, anchovies, herring, and smelts) in the NCC collected in May and June of 2011 and June 2012, and found high diet variability between and within species on seasonal and annual time scales, and also on decadal scales when compared to results of past studies conducted in the early 2000s. Copepoda were a large proportion by weight of several forage fish diets in 2011 and 2012, which differed from a preponderance of Euphausiidae found in previous studies, even though all years exhibited cool ocean conditions. We also examined diet overlap among these species and with co-occurring subyearling Chinook salmon and found that surf smelt diets overlapped more with subyearling Chinook diets than any other forage fish. Herring and sardine diets overlapped the most with each other in our interdecadal comparisons and some prey items were common to all forage fish diets. Forage fish that show plasticity in diet may be more adapted to ocean conditions of low productivity or anomalous prey fields. These findings highlight the variable and not well-understood connections between ocean conditions and energy pathways within the NCC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PrOce.138..504D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PrOce.138..504D"><span id="translatedtitle">An individual-based model of the krill Euphausia pacifica in the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dorman, Jeffrey G.; Sydeman, William J.; Bograd, Steven J.; Powell, Thomas M.</p> <p>2015-11-01</p> <p>Euphausia pacifica is an abundant and important prey resource for numerous predators of the <span class="hlt">California</span> <span class="hlt">Current</span> and elsewhere in the North Pacific. We developed an individual-based model (IBM) for E. pacifica to study its bioenergetics (growth, stage development, reproduction, and mortality) under constant/ideal conditions as well as under varying ocean conditions and food resources. To model E. pacifica under varying conditions, we coupled the IBM to an oceanographic-<span class="hlt">ecosystem</span> model over the period 2000-2008 (9 years). Model results under constant/ideal food conditions compare favorably with experimental studies conducted under food unlimited conditions. Under more realistic variable oceanographic conditions, mean growth rates over the continental shelf were positive only when individuals migrated diurnally to the depth of maximum phytoplankton layer during nighttime feeding. Our model only used phytoplankton as prey and coastal growth rates were lower than expected (0.01 mm d-1), suggesting that a diverse prey base (zooplankton, protists, marine snow) may be required to facilitate growth and survival of modeled E. pacifica in the coastal environment. This coupled IBM-ROMS modeling framework and its parameters provides a tool for understanding the biology and ecology of E. pacifica and could be developed to further the understanding of climatic effects on this key prey species and enhance an <span class="hlt">ecosystem</span> approach to fisheries and wildlife management in this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26220498','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26220498"><span id="translatedtitle">The impact of El Niño events on the pelagic food chain in the northern <span class="hlt">California</span> <span class="hlt">Current</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fisher, Jennifer L; Peterson, William T; Rykaczewski, Ryan R</p> <p>2015-12-01</p> <p>The zooplankton of the northern <span class="hlt">California</span> <span class="hlt">Current</span> are typically characterized by an abundance of lipid-rich copepods that support rapid growth and survival of ecologically, commercially, and recreationally valued fish, birds, and mammals. Disruption of this food chain and reduced <span class="hlt">ecosystem</span> productivity are often associated with climatic variability such as El Niño events. We examined the variability in timing, magnitude, and duration of positive temperature anomalies and changes in copepod species composition in the northern <span class="hlt">California</span> <span class="hlt">Current</span> in relation to 10 tropical El Niño events. Measurable impacts on mesozooplankton of the northern <span class="hlt">California</span> <span class="hlt">Current</span> were observed during seven of 10 of these events. The occurrence of anomalously warm water and the response of the copepod community was rapid (lag of zero to 2 months) following the initiation of canonical Eastern Pacific (EP) events, but delayed (lag of 2-8 months) following 'Modoki' Central Pacific (CP) events. The variable lags in the timing of a physical and biological response led to impacts in the northern <span class="hlt">California</span> <span class="hlt">Current</span> peaking in winter during EP events and in the spring during CP events. The magnitude and duration of the temperature and copepod anomalies were strongly and positively related to the magnitude and duration of El Niño events, but were also sensitive to the phase of the lower frequency Pacific Decadal Oscillation. When fisheries managers and biological oceanographers are faced with the prospect of a future El Niño event, prudent management and observation will require consideration of the background oceanographic conditions, the type of event, and both the magnitude and duration of the event when assessing the potential physical and biological impacts on the northern <span class="hlt">California</span> <span class="hlt">Current</span>. PMID:26220498</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70021229','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70021229"><span id="translatedtitle">Anthropogenic degradation of the southern <span class="hlt">California</span> desert <span class="hlt">ecosystem</span> and prospects for natural recovery and restoration</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lovich, J.E.; Bainbridge, D.</p> <p>1999-01-01</p> <p>Large areas of the southern <span class="hlt">California</span> desert <span class="hlt">ecosystem</span> have been negatively affected by off-highway vehicle use, overgrazing by domestic livestock, agriculture, urbanization, construction of roads and utility corridors, air pollution, military training exercises, and other activities. Secondary contributions to degradation include the proliferation of exotic plant species and a higher frequency of an- thropogenic fire. Effects of these impacts include alteration or destruction of macro- and micro- vegetation elements, establishment of annual plant communities dominated by exotic species, destruction of soil stabilizers, soil compaction, and increased erosion. Published estimates of recovery time are based on return to predisturbance levels of biomass, cover, density, community structure, or soil characteristics. Natural recovery rates depend on the nature and severity of the impact but are generally very slow. Recovery to predisturbance plant cover and biomass may take 50-300 years, while complete <span class="hlt">ecosystem</span> recovery may require over 3000 years. Restorative intervention can be used to enhance the success and rate of recovery, but the costs are high and the probability for long-term success is low to moderate. Given the sensitivity of desert habitats to disturbance and the slow rate of natural recovery, the best management option is to limit the extent and intensity of impacts as much as possible.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011GeoRL..3812607B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011GeoRL..3812607B"><span id="translatedtitle">Transport and coastal zooplankton communities in the northern <span class="hlt">California</span> <span class="hlt">Current</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bi, Hongsheng; Peterson, William T.; Strub, Paul T.</p> <p>2011-06-01</p> <p>Alongshore transport was estimated from the gridded AVISO altimeter data and water level data from NOAA tide gauges (1993-2010) for the northern <span class="hlt">California</span> <span class="hlt">Current</span> (NCC) system. The biomass of the cold neritic copepods including Calanus marshallae, Pseudocalanus mimus and Acartia longiremis (dominants in the eastern Bering Sea, coastal Gulf of Alaska, and NCC) was estimated from a 15 year time series of zooplankton samples (1996-2010) collected biweekly at a coastal station 9 km off Newport Oregon U.S.A. The alongshore <span class="hlt">currents</span> and the biomass of the cold neritic copepods exhibit a strong seasonal pattern and fluctuate in opposite phase: positive alongshore <span class="hlt">current</span> (from south) leads to low biomass in winter and negative alongshore <span class="hlt">current</span> (from north) leads to high biomass in summer. When the Pacific Decadal Oscillation (PDO) is positive, i.e., warm conditions around the northeast Pacific, there is more movement of water from the south in the NCC during winter. When the PDO is negative, there is more movement of water from the north during summer. The mean biomass of cold neritic copepods was positively correlated with the survival rate of juvenile coho salmon and cumulative transport was negatively correlated with coho salmon survival, i.e., in years when a greater portion of the source waters feeding the NCC enters from the north, the greater the salmon survival. We conclude that alongshore transport manifests PDO signals and serves as a linkage between large scale forcing to local <span class="hlt">ecosystem</span> dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25230478','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25230478"><span id="translatedtitle">Disturbance facilitates the coexistence of antagonistic <span class="hlt">ecosystem</span> engineers in <span class="hlt">California</span> estuaries.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Castorani, Max C N; Hovel, Kevin A; Williams, Susan L; Baskett, Marissa L</p> <p>2014-08-01</p> <p>Ecological theory predicts that interactions between antagonistic <span class="hlt">ecosystem</span> engineers can lead to local competitive exclusion, but disturbance can facilitate broader coexistence. However, few empirical studies have tested the potential for disturbance to mediate competition between engineers. We examined the capacity for disturbance and habitat modification to explain the disjunct distributions of two benthic <span class="hlt">ecosystem</span> engineers, eelgrass Zostera marina and the burrowing ghost shrimp Neotrypaea californiensis, in two <span class="hlt">California</span> estuaries. Sediment sampling in eelgrass and ghost shrimp patches revealed that ghost shrimp change benthic biogeochemistry over small scales (centimeters) but not patch scales (meters to tens of meters), suggesting a limited capacity for sediment modification to explain species distributions. To determine the relative competitive abilities of engineers, we conducted reciprocal transplantations of ghost shrimp and eelgrass. Local ghost shrimp densities declined rapidly following the addition of eelgrass, and transplanted eelgrass expanded laterally into the surrounding ghost shrimp-dominated areas. When transplanted into eelgrass patches, ghost shrimp failed to persist. Ghost shrimp were also displaced from plots with structural mimics of eelgrass rhizomes and roots, suggesting that autogenic habitat modification by eelgrass is an important mechanism determining ghost shrimp distributions. However, ghost shrimp were able to rapidly colonize experimental disturbances to eelgrass patch edges, which are common in shallow estuaries. We conclude that coexistence in this system is maintained by spatiotemporally asynchronous disturbances and a competition-colonization trade-off: eelgrass is a competitively superior <span class="hlt">ecosystem</span> engineer, but benthic disturbances permit the coexistence of ghost shrimp at the landscape scale by modulating the availability of space. PMID:25230478</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B51I0414D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B51I0414D"><span id="translatedtitle">Measurement of <span class="hlt">Ecosystem</span> Metabolism across Climatic and Vegetation Gradients in <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>DuBois, S.; Serbin, S.; Desai, A. R.; Kruger, E.; Kingdon, C.; Goulden, M.; Townsend, P. A.</p> <p>2013-12-01</p> <p>Terrestrial <span class="hlt">ecosystem</span> models require information on vegetation structure, phenology, demographics, biochemistry, radiation properties, and physiology in order to accurately simulate the responses of <span class="hlt">ecosystem</span> functioning to global change and disturbances. These models generally depend on a small number of intensive, fine-scaled point-based measurements from eddy covariance towers, detailed vegetation surveys, literature values, and site-scale data assimilation techniques to improve model calibration. However, the limited geographic and/or temporal scope of measurements can lead to inadequate model generalizations of modeled carbon (C), water, and energy fluxes across broad regions and relevant time periods. Remote sensing approaches, particularly imaging spectroscopy (IS) and thermal infrared (TIR) data, have the potential to provide the broad-scale spatial and temporal dynamics in many important vegetation properties related to <span class="hlt">ecosystem</span> functioning. As part of the ongoing NASA HyspIRI Airborne Campaign (http://hyspiri.jpl.nasa.gov/airborne) we are assessing the potential of IS+TIR to generate spatially explicit estimates of two important parameters characterizing plant photosynthetic capacity: the maximum rate of CO2 carboxylation by RuBisCo (Vcmax), and the maximum rate of electron transport required for the regeneration of RuBP needed in Calvin Cycle processes (Jmax). These estimates are based on recent evidence that both properties can be predicted at the leaf level using spectroscopy techniques (Ainsworth et al. 2013 [http://tinyurl.com/n5xnzjg]; Serbin et al. 2012 [http://tinyurl.com/mhocmlz]). It follows that estimation of these variables from remotely sensed IS+TIR (i.e. AVIRIS & MASTER) could facilitate the prediction of seasonal C assimilation across large areas using data from the anticipated HyspIRI satellite mission. Our research focuses on two climate-elevation transects in <span class="hlt">California</span>, which span a vegetation gradient from coastal sage and chaparral to oak woodlands and closed-canopy coniferous forests, as well as agro-<span class="hlt">ecosystems</span> located throughout the Central and Imperial Valleys. We are also comparing remotely sensed estimates of <span class="hlt">ecosystem</span> photosynthetic capacity with C flux data from a series of 10 eddy covariance towers. Results from the 2013 field season highlight the large range in sampled vegetation structure, optical properties (i.e. reflectance and transmittance) and physiology (i.e. Vcmax, Jmax, and cholorphyll fluorescence). Using approaches similar to Serbin et al. (2012) we have confirmed the ability of spectroscopy to estimate Vcmax and Jmax across these diverse and structurally complex vegetation types. <span class="hlt">Ecosystem</span> products, such as gross primary productivity, estimated from flux towers highlight the relationship between climatic parameters and vegetation productivity. Multiple data-years allow this relationship to be examined under various climatic forcings including drought and heat stress. Based on these preliminary results, our next step is to scale leaf-level information to AVIRIS footprints using radiative transfer and statistical modeling approaches with <span class="hlt">ecosystem</span> modeling in order to assess the IS data products against flux tower observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........18A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........18A"><span id="translatedtitle">Topographic Controls on Southern <span class="hlt">California</span> <span class="hlt">Ecosystem</span> Function and Post-fire Recovery: a Satellite and Near-surface Remote Sensing Approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Azzari, George</p> <p></p> <p>Southern Californian wildfires can influence climate in a variety of ways, including changes in surface albedo, emission of greenhouse gases and aerosols, and the production of tropospheric ozone. <span class="hlt">Ecosystem</span> post-fire recovery plays a key role in determining the strength, duration, and relative importance of these climate forcing agents. Southern <span class="hlt">California</span>'s <span class="hlt">ecosystems</span> vary markedly with topography, creating sharp transitions with elevation, aspect, and slope. Little is known about the ways topography influences <span class="hlt">ecosystem</span> properties and function, particularly in the context of post-fire recovery. We combined images from the USGS satellite Landsat 5 with flux tower measurements to analyze pre- and post-fire albedo and carbon exchanged by Southern <span class="hlt">California</span>'s <span class="hlt">ecosystems</span> in the Santa Ana Mountains. We reduced the sources of external variability in Landsat images using several correction methods for topographic and bidirectional effects. We used time series of corrected images to infer the Net <span class="hlt">Ecosystem</span> Exchange and surface albedo, and calculated the radiative forcing due to CO2 emissions and albedo changes. We analyzed the patterns of recovery and radiative forcing on north- and south-facing slopes, stratified by vegetation classes including grassland, coastal sage scrub, chaparral, and evergreen oak forest. We found that topography strongly influenced post-fire recovery and radiative forcing. Field observations are often limited by the difficulty of collecting ground validation data. <span class="hlt">Current</span> instrumentation networks do not provide adequate spatial resolution for landscape-level analysis. The deployment of consumer-market technology could reduce the cost of near-surface measurements, allowing the installation of finer-scale instrument networks. We tested the performance of the Microsoft Kinect sensor for measuring vegetation structure. We used Kinect to acquire 3D vegetation point clouds in the field, and used these data to compute plant height, crown diameter, and volume. We found good agreement between Kinect-derived and manual measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5348702','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5348702"><span id="translatedtitle"><span class="hlt">Current</span> <span class="hlt">California</span> legislative and regulatory activity impacting geothermal hydrothermal commercialization: a monitoring report. Report No. 1017</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1980-01-20</p> <p>Four key geothermal-impacting bills presently before the <span class="hlt">California</span> legislature are described. Two deal with state financial backing for geothermal projects. The third relates to the use of the state's share of the BLM geothermal revenues and the fourth to the protection of sensitive hot springs. The <span class="hlt">current</span> regulatory activities of the <span class="hlt">California</span> Energy Commission, the <span class="hlt">California</span> Division of Oil and Gas, and the counties are discussed. (MHR)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRC..118.3223P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRC..118.3223P"><span id="translatedtitle">Modeling the temperature-nitrate relationship in the coastal upwelling domain of the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Palacios, Daniel M.; Hazen, Elliott L.; Schroeder, Isaac D.; Bograd, Steven J.</p> <p>2013-07-01</p> <p>Given the importance of nitrate in sustaining high primary production and fishery yields in eastern boundary <span class="hlt">current</span> <span class="hlt">ecosystems</span>, it is desirable to know the amounts of this nutrient reaching the euphotic zone through the upwelling process. Because such measurements are not routinely available, we developed predictive models of water-column (0-200 m) nitrate based on temperature for a region of the <span class="hlt">California</span> <span class="hlt">Current</span> System (30-47°N) within 50 km from the coast. Prediction was done using generalized additive models based on a compilation of 37,607 observations collected over the period 1959-2004 and validated with a separate set of 6430 observations for the period 2005-2011. A temperature-only model had relatively high explanatory power (explained deviance, D2 = 71.6%) but contained important depth, latitudinal, and seasonal biases. A model incorporating salinity in addition to temperature (D2 = 91.2%) corrected for the latitudinal and depth biases but not the seasonal bias. The best model included oxygen, temperature, and salinity (D2 = 96.6%) and adequately predicted nitrate temporal behavior at two widely separated locations (44°39.1'N and 32°54.6'N) with slight or no bias [root-mean-square error (RMSE) = 2.39 and 0.40 µM, respectively). For situations when only temperature is available, a model including depth, month, and latitude as proxy covariates corrects some of the biases, but it had lower predictive skill (RMSE = 2.50 and 5.22 μM, respectively). The results of this study have applications for the proxy derivation of nitrate availability for primary producers (phytoplankton, macroalgae) in upwelling regions and for biogeochemical and <span class="hlt">ecosystem</span> modeling studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JGRC..114.0B03H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JGRC..114.0B03H"><span id="translatedtitle">Three interacting freshwater plumes in the northern <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hickey, B.; McCabe, R.; Geier, S.; Dever, E.; Kachel, N.</p> <p>2009-02-01</p> <p>The northern <span class="hlt">California</span> <span class="hlt">Current</span> System is impacted by two primary freshwater sources: the Strait of Juan de Fuca and the Columbia River. The Columbia is frequently bidirectional in summer, with branches both north and south of the river mouth simultaneously. We describe the interaction of these two warm Columbia plumes with each other and with the colder plume originating from the strait. The interactions occurred when a period of strong downwelling-favorable winds and high Columbia River discharge was followed by persistent and strong upwelling-favorable winds. The northward plume that developed under the downwelling winds extended over 200 km along the coast to the Strait of Juan de Fuca and into the strait. The plume subsequently wrapped around Juan de Fuca Strait water in the counterclockwise seasonal eddy just offshore of the strait. Inspection for similar wind and outflow conditions (>0.15 N m-2 and 104 m3 s-1, respectively) suggest that these events might have occurred in roughly half the years since 1994. Surface drifters deployed in the Columbia plume near its origin tracked this plume water northward along the coast, then reversed direction at the onset of upwelling-favorable winds, tracking plume water southward past the river mouth once again. "Recent" (1-2 day old) and "Aged" (>14 day old) plume water folded around the newly emerging southwest tending Columbia plume, forming a distinctive "sock" shaped plume. This plume was a mixture of 10% "New" (<1 day old) water and 90% Recent and Aged water from prior north tending plumes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2867361','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2867361"><span id="translatedtitle">Processes influencing seasonal hypoxia in the northern <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Connolly, T. P.; Hickey, B. M.; Geier, S. L.; Cochlan, W. P.</p> <p>2010-01-01</p> <p>This paper delineates the role of physical and biological processes contributing to hypoxia, dissolved oxygen (DO) < 1.4 mL/L, over the continental shelf of Washington State in the northern portion of the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS). In the historical record (1950–1986) during the summer upwelling season, hypoxia is more prevalent and severe off Washington than further south off northern Oregon. Recent data (2003–2005) show that hypoxia over the Washington shelf occurred at levels previously observed in the historical data. 2006 was an exception, with hypoxia covering ~5000 km2 of the Washington continental shelf and DO concentrations below 0.5 mL/L at the inner shelf, lower than any known previous observations at that location. In the four years studied, upwelling of low DO water and changes in source water contribute to interannual variability, but cannot account for seasonal decreases below hypoxic concentrations. Deficits of DO along salinity surfaces, indicating biochemical consumption of DO, vary significantly between surveys, accounting for additional decreases of 0.5–2.5 mL/L by late summer. DO consumption is associated with denitrification, an indicator of biochemical sediment processes. Mass balances of DO and nitrate show that biochemical processes in the water column and sediments each contribute ~50% to the total consumption of DO in near-bottom water. At shorter than seasonal time scales on the inner shelf, along-shelf advection of hypoxic patches and cross-shelf advection of seasonal gradients are both shown to be important, changing DO concentrations by 1.5 mL/L or more over five days. PMID:20463844</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRC..120.1691J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRC..120.1691J"><span id="translatedtitle">ENSO and the <span class="hlt">California</span> <span class="hlt">Current</span> coastal upwelling response</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jacox, Michael G.; Fiechter, Jerome; Moore, Andrew M.; Edwards, Christopher A.</p> <p>2015-03-01</p> <p>A 31 year (1980-2010) sequence of historical analyses of the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS) is used to describe the central CCS (35-43˚N) coastal upwelling response to El Niño-Southern Oscillation (ENSO) variability. The analysis period captures 10 El Niño and 10 La Niña events, including the extreme El Niños of 1982-1983 and 1997-1998. Data-assimilative model runs and backward trajectory calculations of passive tracers are used to elucidate physical conditions and source water characteristics during the upwelling season of each year. In general, El Niño events produce anomalously weak upwelling and source waters that are unusually shallow, warm, and fresh, while La Niña conditions produce the opposite. Maximum vertical transport anomalies in the CCS occur ˜1 month after El Niño peaks in midwinter, and before the onset of the upwelling season. Source density anomalies peak later than transport anomalies and persist more strongly through the spring and summer, causing the former to impact the upwelling season more directly. As nitrate concentration covaries with density in the central CCS, El Niño may exert more influence over the nitrate concentration of upwelled waters than it does over vertical transport, although both factors are expected to reduce nitrate supply during El Niño events. Interannual comparison of individual diagnostics highlights their relative impacts during different ENSO events, as well as years deviating from the canonical response to ENSO variability. The net impact of ENSO on upwelling is explored through an "Upwelling Efficacy Index", which may be a useful indicator of bottom-up control on primary productivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H42E..02H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H42E..02H"><span id="translatedtitle">Water Use in Los Angeles, <span class="hlt">California</span>: Consumption Patterns, <span class="hlt">Ecosystem</span> Response and Impact on Regional Water Budgets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hogue, T. S.</p> <p>2014-12-01</p> <p>The City of Los Angeles relies heavily on external water sources, primarily the Eastern Sierra, Northern <span class="hlt">California</span> and the Colorado River, and approximately 90% of the City's water supply is snowpack dependent. In recent years, water conservation measures have been implemented in response to regional drought, which include a tiered pricing structure and watering restrictions. As a result of implemented conservation policies, Los Angeles reported the lowest water consumption per capita per day in 2011 among cities over 1 million people in the U.S. This presentation will highlight our ongoing work to better understand the coupling between humans, <span class="hlt">ecosystems</span> and water across the City of Los Angeles, especially during the recent drought period. Our work is unique in that we integrate social, ecological, and hydrologic data, including ten years of residential water consumption data for the entire city of Los Angeles, extensive groundwater well data, socio-economic information and remote sensing to evaluate relationships as well as spatial and temporal patterns. Developed statistical models demonstrated that Single-Family Residential (SFR) water use across the City is primarily driven by household income, landscape greenness, water rates and water volume allocation,, with higher consumption rates in the northern, warmer and more affluent parts, and lower consumption rates in the less affluent neighborhoods near Downtown. Landscape use also varies greatly across the city, averaging 50% of total SFR. Our evaluation of conservation efforts shows that the combination of mandatory watering restrictions and price increase led to a water reduction of 23%, while voluntary restrictions led to only a 6% reduction in water use. Relationships of water use to <span class="hlt">ecosystems</span> (greenness) and groundwater variability were also evaluated and will be highlighted. Our ultimate goal is to improve predictions of human-water interactions in order to drive policy change and guide future demand strategies under uncertain climate variability and a growing urban population.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.B12B..07C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.B12B..07C"><span id="translatedtitle">The diel patterns of soil respiration in four arid <span class="hlt">California</span> <span class="hlt">ecosystems</span>: fluxes, sources and hypotheses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carbone, M.; Trumbore, S.; Winston, G.; Serio, D.</p> <p>2007-12-01</p> <p>Automated measurements provide the high-resolution information that enables us to analyze potential causes for diel variability in soil respiration. These diel patterns are the complex result of biological and physical processes that determine the production and diffusion of CO2 through the soil. We examined the diel patterns of soil respiration from four arid <span class="hlt">California</span> <span class="hlt">ecosystems</span>: (1) a pinon-juniper woodland in at the Burns Pinon Ridge Reserve near Joshua Tree National Park, (2) a cold desert shrub community and (3) a perennial grassland near the city of Bishop in the Owens Valley, and (4) a mixed oak-pine forest at the James Reserve in the San Jacinto Mountains. In addition to automated chamber and environmental measurements at these sites, we used isotopic (14C) partitioning techniques to separate the plant and microbial sources contributing to soil respiration at certain time points. Here we present the diel cycles of soil respiration and environmental variables, the source partitioning results, and hypotheses about what processes determine these diel patterns that both span, and are specific to the studied <span class="hlt">ecosystems</span>. In these systems dominated by Mediterranean or desert climates, we observed that factors like relative humidity can dominate the diel variations in soil respiration for sites with very dry surface litter. At other sites and times of year, diel variation in soil respiration reflects photosynthetic and VPD influence on root respiration. The combination of automated chamber measurements with isotopes provides information useful for separating the plant and heterotrophic control on diel and seasonal soil respiration fluxes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25990583','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25990583"><span id="translatedtitle">The <span class="hlt">current</span> state of knowledge of <span class="hlt">ecosystems</span> and <span class="hlt">ecosystem</span> services in Russia: A status report.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bukvareva, Elena N; Grunewald, Karsten; Bobylev, Sergey N; Zamolodchikov, Dimitry G; Zimenko, Alexey V; Bastian, Olaf</p> <p>2015-10-01</p> <p>This paper focusses on a conceptual overview of ways to address a comprehensive analysis of <span class="hlt">ecosystem</span> services (ES) in a country as large and heterogeneous as Russia. As a first step, a methodology for assessing the services for the federal subjects of Russia was chosen, i.e., its constituent provinces and similar entities, in physical terms. Russia harbors a great diversity of natural conditions and <span class="hlt">ecosystems</span> which are suppliers of ES, and likewise a variety of the socio-economic conditions that shape the demand for these services and their consumption. The methodological approach described permits several important tasks to be addressed: the evaluation of the degree of satisfaction of people's needs for ES, the identification of ecological donor and acceptor regions, and zoning of the country's territory for ES assessment. The next step is to prepare a prototype of a National Report on ES in Russia, for which we are presenting the planned structure. PMID:25990583</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20705383','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20705383"><span id="translatedtitle">Nitrogen critical loads and management alternatives for N-impacted <span class="hlt">ecosystems</span> in <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fenn, M E; Allen, E B; Weiss, S B; Jovan, S; Geiser, L H; Tonnesen, G S; Johnson, R F; Rao, L E; Gimeno, B S; Yuan, F; Meixner, T; Bytnerowicz, A</p> <p>2010-12-01</p> <p>Empirical critical loads for N deposition effects and maps showing areas projected to be in exceedance of the critical load (CL) are given for seven major vegetation types in <span class="hlt">California</span>. Thirty-five percent of the land area for these vegetation types (99,639 km(2)) is estimated to be in excess of the N CL. Low CL values (3-8 kg N ha(-1) yr(-1)) were determined for mixed conifer forests, chaparral and oak woodlands due to highly N-sensitive biota (lichens) and N-poor or low biomass vegetation in the case of coastal sage scrub (CSS), annual grassland, and desert scrub vegetation. At these N deposition critical loads the latter three <span class="hlt">ecosystem</span> types are at risk of major vegetation type change because N enrichment favors invasion by exotic annual grasses. Fifty-four and forty-four percent of the area for CSS and grasslands are in exceedance of the CL for invasive grasses, while 53 and 41% of the chaparral and oak woodland areas are in exceedance of the CL for impacts on epiphytic lichen communities. Approximately 30% of the desert (based on invasive grasses and increased fire risk) and mixed conifer forest (based on lichen community changes) areas are in exceedance of the CL. These <span class="hlt">ecosystems</span> are generally located further from emissions sources than many grasslands or CSS areas. By comparison, only 3-15% of the forested and chaparral land areas are estimated to be in exceedance of the NO(3)(-) leaching CL. The CL for incipient N saturation in mixed conifer forest catchments was 17 kg N ha(-1) yr(-1). In 10% of the CL exceedance areas for all seven vegetation types combined, the CL is exceeded by at least 10 kg N ha(-1) yr(-1), and in 27% of the exceedance areas the CL is exceeded by at least 5 kg N ha(-1) yr(-1). Management strategies for mitigating the effects of excess N are based on reducing N emissions and reducing site N capital through approaches such as biomass removal and prescribed fire or control of invasive grasses by mowing, selective herbicides, weeding or domestic animal grazing. Ultimately, decreases in N deposition are needed for long-term <span class="hlt">ecosystem</span> protection and sustainability, and this is the only strategy that will protect epiphytic lichen communities. PMID:20705383</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PrOce..77..182J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PrOce..77..182J"><span id="translatedtitle"><span class="hlt">Ecosystem</span> responses to short-term climate variability in the Gulf of the Farallones, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jahncke, J.; Saenz, B. L.; Abraham, C. L.; Rintoul, C.; Bradley, R. W.; Sydeman, W. J.</p> <p>2008-05-01</p> <p>We conducted an integrated study from physics to upper trophic-level predators in the Gulf of the Farallones, <span class="hlt">California</span>. We hypothesized that decreased zooplankton abundance for upper trophic-level predators in the Gulf of the Farallones during 2004 and 2005 was a response to reduced upwelling-favorable winds and primary production. Based on their trophic ecology, we hypothesized that planktivorous auklets and omnivorous murres will show differential responses to upwelling variability. We examined these hypotheses by analyzing time series on oceanographic variables associated to upwelling and the biological responses at low, mid and high trophic-levels. We found that reduced upwelling-favorable wind was correlated with anomalously high SST and low chlorophyll a concentration from July 2004 to August 2005. During 2005, low chlorophyll concentrations were related to reduced krill abundance in the upper water column and decreased seabird abundance in the vicinity of the breeding colony in the study area. Decreased krill abundance was associated with late timing of nesting and reduced breeding success, with auklets showing a more pronounced response. This study shows how short-term climate variability can affect primary through tertiary productivity, and supports an interpretation of bottom-up control of <span class="hlt">ecosystem</span> dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H21F0898E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H21F0898E"><span id="translatedtitle">Fog and Rain Water Influences on Tree Physiology and <span class="hlt">Ecosystem</span> Function in a <span class="hlt">California</span> Redwood Forest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ewing, H. A.; Weathers, K. C.; Dawson, T. E.; Templer, P. H.; Firestone, M. K.; Elliott, A. M.; Boukili, V. K.</p> <p>2008-12-01</p> <p>Fog is thought to influence ecological function in coastal forests worldwide, yet few data are available that illuminate the mechanisms underlying this influence. In a <span class="hlt">California</span> redwood forest we measured water fluxes from horizontally moving fog and vertically delivered rain as well as redwood tree function. The spatial heterogeneity of water fluxes, water availability, tree water use, and water movement varied greatly across seasons. Across the forest as a whole, 98% of water flux to the soil occurred in the rain season and was relatively even across the whole forest. In contrast, below-canopy flux of fog water declined exponentially from the windward edge to the forest interior. Following large fog events, soil moisture was greater at the windward edge than anywhere else in the forest. Physiological activity in redwoods reflected these differences in inputs across seasons: tree physiological responses did not vary spatially in the rain season, but in the fog season, water use was greater, yet water stress was less, in trees at the windward edge of the forest versus the interior. In both seasons, vertical passage through the forest changed the amount of water, revealing the role of both the tree canopy and roots in processing atmospheric inputs. While total fog water inputs were comparatively small, they may have important <span class="hlt">ecosystem</span> functions, including relief of canopy water stress and, where there is fog drip, functional coupling of above- and below-ground processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23504918','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23504918"><span id="translatedtitle">Increasing variance in North Pacific climate relates to unprecedented <span class="hlt">ecosystem</span> variability off <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sydeman, William J; Santora, Jarrod A; Thompson, Sarah Ann; Marinovic, Baldo; Di Lorenzo, Emanuele</p> <p>2013-06-01</p> <p>Changes in variance are infrequently examined in climate change ecology. We tested the hypothesis that recent high variability in demographic attributes of salmon and seabirds off <span class="hlt">California</span> is related to increasing variability in remote, large-scale forcing in the North Pacific operating through changes in local food webs. Linear, indirect numerical responses between krill (primarily Thysanoessa spinifera) and juvenile rockfish abundance (catch per unit effort (CPUE)) explained >80% of the recent variability in the demography of these pelagic predators. We found no relationships between krill and regional upwelling, though a strong connection to the North Pacific Gyre Oscillation (NPGO) index was established. Variance in NPGO and related central Pacific warming index increased after 1985, whereas variance in the canonical ENSO and Pacific Decadal Oscillation did not change. Anthropogenic global warming or natural climate variability may explain recent intensification of the NPGO and its increasing ecological significance. Assessing non-stationarity in atmospheric-environmental interactions and placing greater emphasis on documenting changes in variance of bio-physical systems will enable insight into complex climate-marine <span class="hlt">ecosystem</span> dynamics. PMID:23504918</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=brunt&pg=5&id=ED275473','ERIC'); return false;" href="http://eric.ed.gov/?q=brunt&pg=5&id=ED275473"><span id="translatedtitle"><span class="hlt">Current</span> and Future Effects of Mexican Immigration in <span class="hlt">California</span>. Executive Summary. R-3365/1-CR.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>McCarthy, Kevin F.; Valdez, R. Burciaga</p> <p></p> <p>This study to assess the <span class="hlt">current</span> situation of Mexican immigrants in <span class="hlt">California</span> and project future possibilities constructs a demographic profile of the immigrants, examines their economic effects on the state, and describes their socioeconomic integration into <span class="hlt">California</span> society. Models of immigration/integration processes are developed and used</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=population+AND+structure+AND+Native+AND+Mexicans&id=ED275473','ERIC'); return false;" href="http://eric.ed.gov/?q=population+AND+structure+AND+Native+AND+Mexicans&id=ED275473"><span id="translatedtitle"><span class="hlt">Current</span> and Future Effects of Mexican Immigration in <span class="hlt">California</span>. Executive Summary. R-3365/1-CR.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>McCarthy, Kevin F.; Valdez, R. Burciaga</p> <p></p> <p>This study to assess the <span class="hlt">current</span> situation of Mexican immigrants in <span class="hlt">California</span> and project future possibilities constructs a demographic profile of the immigrants, examines their economic effects on the state, and describes their socioeconomic integration into <span class="hlt">California</span> society. Models of immigration/integration processes are developed and used…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=258994','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=258994"><span id="translatedtitle"><span class="hlt">Current</span> status of Citrus tristeza virus in Central <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>The Lindcove Research and Extension Center (LREC), Exeter, CA has 51 ha of citrus and is the field site and screenhouses for the University of <span class="hlt">California</span> Citrus Clonal Protection Program (CCPP). LREC maintains a zero tolerance of Citrus tristeza virus (CTV) infected trees to protect the CCPP and re...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013DSRII..95...37F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013DSRII..95...37F"><span id="translatedtitle">Foraging ecology and movement patterns of jumbo squid (Dosidicus gigas) in the <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Field, John C.; Elliger, Carl; Baltz, Ken; Gillespie, Graham E.; Gilly, William F.; Ruiz-Cooley, R. I.; Pearse, Devon; Stewart, Julia S.; Matsubu, William; Walker, William A.</p> <p>2013-10-01</p> <p>From 2002 to 2010, the jumbo squid (Dosidicus gigas) has been regularly encountered in large numbers throughout the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS). This species, usually found in subtropical waters, could affect coastal pelagic <span class="hlt">ecosystems</span> and fisheries as both predator and prey. Neither the abundance of jumbo squid nor the optimal ocean conditions in which they flourish are well known. To understand better the potential impacts of this species on both commercial fisheries and on food-web structure we collected nearly 900 specimens from waters of the CCS, covering over 20 of latitude, over a range of depths and seasons. We used demographic information (size, sex, and maturity state) and analyzed stomach contents using morphological and molecular methods to best understand the foraging ecology of this species in different habitats of the CCS. Squid were found to consume a broad array of prey. Prey in offshore waters generally reflected the forage base reported in previous studies (mainly mesopelagic fishes and squids), whereas in more coastal waters (shelf, shelf break and slope habitats) squid foraged on a much broader mix that included substantial numbers of coastal pelagic fishes (Pacific herring and northern anchovy, as well as osmerids and salmonids in northern waters) and groundfish (Pacific hake, several species of rockfish and flatfish). We propose a seasonal movement pattern, based on size and maturity distributions along with qualitative patterns of presence or absence, and discuss the relevance of both the movement and distribution of jumbo squid over space and time. We find that jumbo squid are a generalist predator, which feeds primarily on small, pelagic or mesopelagic micronekton but also on larger fishes when they are available. We also conclude that interactions with and potential impacts on <span class="hlt">ecosystems</span> likely vary over space and time, in response to both seasonal movement patterns and highly variable year-to-year abundance of the squid themselves.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMOS23A1570A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMOS23A1570A"><span id="translatedtitle">Predictive Relationships for pH and Carbonate Saturation in the Southern <span class="hlt">California</span> <span class="hlt">Current</span> System Using Oxygen and Temperature Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alin, S. R.; Feely, R. A.; Dickson, A. G.; Hernandez-Ayon, J. M.; Juranek, L. W.; Ohman, M. D.; Goericke, R.</p> <p>2010-12-01</p> <p>The <span class="hlt">California</span> <span class="hlt">Current</span> System is expected to experience the ecological impacts of ocean acidification earlier than most other ocean regions because marine waters in the North Pacific are among the oldest in the global oceans and natural upwelling processes in this eastern boundary <span class="hlt">current</span> system bring CO2-rich water masses to the surface in coastal oceans during late spring-early fall months. We used a multiple linear regression (MLR) approach to generate predictive models using oxygen and temperature as proxy variables to reconstruct pH and carbonate saturation states in the Southern <span class="hlt">California</span> Bight. The calibration data set included high-quality measurements of dissolved inorganic carbon, alkalinity, oxygen, temperature, salinity, and nutrients and was collected during a cruise from British Columbia to Baja <span class="hlt">California</span> in May-June 2007. The resulting relationships predicting pH and aragonite and calcite saturation states (?) from oxygen and temperature data were robust, with r2 values >0.98 and root mean square errors of 0.020 (pH), 0.048 (?arag), and 0.075 (?calc). Predicted vs. measured ocean acidification conditions (i.e. pH, ?arag, and ?calc) matched very well for seven verification data sets collected between 2008 and 2010 during quarterly CalCOFI cruises in the Southern <span class="hlt">California</span> Bight and during several sampling dates on an Ensenada transect occupied several times between 2006 and 2010. Over sub-decadal time scales, these predictive models provide a valuable tool for reconstructing historical time-series of ocean acidification conditions in the <span class="hlt">California</span> <span class="hlt">Current</span> <span class="hlt">Ecosystem</span> where historical inorganic carbon measurements are scarce. Reconstructed pH and saturation state values based on CalCOFI oxygen and temperature data for all cruises between 2005 and 2010 reveal a seasonal cycle in the upper water column, with higher pH and ? values present during the winter cruises, and stronger gradients including much lower pH and ? values during spring through fall cruises. Deeper in the water column (~300 m), conditions are more stable throughout the annual cycle, with consistently low pH, undersaturation with respect to aragonite, and calcite saturation values <1.5. These predictive relationships can also be used to improve the performance of models used to nowcast and forecast ocean acidification in eastern boundary <span class="hlt">current</span> systems like the <span class="hlt">California</span> <span class="hlt">Current</span> System.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17..645V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17..645V"><span id="translatedtitle"><span class="hlt">Current</span> <span class="hlt">ecosystem</span> processes in steppe near Lake Baikal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vanteeva, Julia</p> <p>2015-04-01</p> <p>The steppes and forest steppes complexes of Priol'khonie at the Lake Baikal (southern Siberia, Russia) were studied in this research. Recreational activity has a significant impact on the Priol'khonie region. During soviet time this area was actively used for agriculture. Nowadays, this territory is the part of Pribaikalskyi National Park and special protection is needed. As the landscapes satisfy different human demands there are many land-management conflicts. The specific climate and soil conditions and human activity lead to erosion processes on study area. Sediment loads are transferred into the Lake Baikal and cause water pollution. Consequently, vegetation cover and phytomass play an important role for regulating hydrological processes in the <span class="hlt">ecosystems</span>. The process of phytomass formation and its proactive role playing on sedimentation and mitigate silt detaching by rill and inter-rill erosion are considered in the research as important indicators of the <span class="hlt">ecosystem</span> functions for steppe landscapes. These indicators were studied for the different land cover types identified on the area because the study area has a large variety of steppe and forest steppe complexes, differing in the form of relief, soil types, vegetation species composition and degree of land degradation. The fieldwork was conducted in the study area in the July and August of 2013. Thirty-two experimental sites (10 x 10 m) which characterized different types of <span class="hlt">ecosystem</span> were established. The level of landscape degradation was estimated. The method of clipping was used for the valuation of above-ground herbaceous phytomass. The phytomass of tree stands was calculated using the volume-conversion rates for forest-steppe complexes. For the quantification of transferred silt by inter-rill erosion in different conditions (vegetation, slope, soil type, anthropogenic load) a portable rainfall simulator was created with taking into account the characteristics of the study area. The aboveground herbaceous phytomass of the steppe complexes varied from 0.4 to 2.64 t/ha. Apical stony and sloping grass-forb landscapes and areas of settlements and recreation facilities had the lowest values. Forest steppes were characterized by low crown density, non-large stand density, which was represented mainly by larch. Phytomass stock ranged from 30.78 to 282.24 t/ha. Maximum values corresponded to the forest steppe with larch on steep slopes. The maximum values of the silt matter transfer (up to 124 g /m2) corresponded to areas with a strong recreation pressure with the lower value of vegetation cover (from 0 to 45%) and aboveground herbaceous phytomass (0.4 - 0.6 t/ha). During experiment with using rainfall simulator defined different sensibility to soil erosion, for example, for Caragana steppe with sagebrush on the undisturbed area trapped silt is 12 g/m2 and for anthropogenic disturbed patch - 84 g/m2. For Sagebrush steppe trapped silt changed from 4 to 16 g/m2. The study shows strong landscapes transformation leading to loss of biodiversity, the reduction of phytomass production and water percolation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25994685','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25994685"><span id="translatedtitle">Material properties of Pacific hake, Humboldt squid, and two species of myctophids in the <span class="hlt">California</span> <span class="hlt">Current</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Becker, Kaylyn N; Warren, Joseph D</p> <p>2015-05-01</p> <p>Material properties of the flesh from three fish species (Merluccius productus, Symbolophorus californiensis, and Diaphus theta), and several body parts of the Humboldt squid (Dosidicus gigas) collected from the <span class="hlt">California</span> <span class="hlt">Current</span> <span class="hlt">ecosystem</span> were measured. The density contrast relative to seawater varied within and among taxa for fish flesh (0.9919-1.036), squid soft body parts (mantle, arms, tentacle, braincase, eyes; 1.009-1.057), and squid hard body parts (beak and pen; 1.085-1.459). Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast relative to seawater varied within and among taxa for fish flesh (0.986-1.027) and Humboldt squid mantle and braincase (0.937-1.028). Material properties in this study are similar to values from previous studies on species with similar life histories. In general, the sound speed and density of soft body parts of fish and squid were 1%-3% and 1%-6%, respectively, greater than the surrounding seawater. Hard parts of the squid were significantly more dense (6%-46%) than seawater. The material properties reported here can be used to improve target strength estimates from acoustic scattering models, which could increase the accuracy of biomass estimates from acoustic surveys for these nekton. PMID:25994685</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.B33F0527A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.B33F0527A"><span id="translatedtitle">Microbial Enzymatic Response to Reduced Precipitation and Added Nitrogen in a Southern <span class="hlt">California</span> Grassland <span class="hlt">Ecosystem</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alster, C. J.; German, D.; Allison, S. D.</p> <p>2011-12-01</p> <p>Microbial enzymes play a fundamental role in <span class="hlt">ecosystem</span> processes and nutrient mineralization. Although there have been many studies concluding that global climate change affects plant communities, the effects on microbial communities in leaf litter have been much less studied. We measured extracellular enzyme activities in litter decomposing in plots with either reduced precipitation or increased nitrogen in a grassland <span class="hlt">ecosystem</span> in Loma Ridge National Landmark in Southern <span class="hlt">California</span>. We used a reciprocal transplant design to examine the effects of plot treatment, litter origin, and microbial community origin on litter decomposition and extracellular enzyme activity. Our hypothesis was that increased nitrogen would increase activity because nitrogen often limits microbial growth, while decreased precipitation would decrease activity due to lower litter moisture levels. Samples were collected in March 2011 and analyzed for the activities of cellobiohydrolase (CBH), β-glucosidase (BG), α-glucosidase (AG), N-acetyl-β-D-glucosaminidase (NAG), β-xylosidase (BX), acid phosphatase (AP), and leucine aminopeptidase (LAP). None of the factors in the nitrogen manipulation had a significant effect on any of the enzymes, although BG, CBH, and NAG increased marginally significantly in plots with nitrogen addition (p = 0.103, p = 0.082, and p = 0.114, respectively). For the precipitation manipulation, AG, BG, BX, CBH, and NAG significantly increased in plots with reduced precipitation (p = 0.015, p <0.001, p<0.001, and p<0.001, respectively) while LAP significantly decreased (p = 0.002). LAP catalyzes the hydrolysis of polypeptides, so reduced LAP activity could result in lower rates of enzyme turnover in the reduced precipitation treatment. We also observed that AP significantly increased (p = 0.014) in litter originating from reduced precipitation plots, while AG, BX, and LAP significantly decreased (p = 0.011, p = 0.031, and 0.005, respectively). There were no significant correlations found between fungal or bacterial mass and enzymatic activity with either of the treatment types. Our results suggest that increased enzymatic activity due to drought could mitigate negative effects of moisture limitation on decomposition. However, this mitigating effect may be offset by declines in enzyme activity due to changes in plant community composition and associated litter chemistry in response to drought.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23691155','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23691155"><span id="translatedtitle">Indirect effects of conservation policies on the coupled human-natural <span class="hlt">ecosystem</span> of the upper Gulf of <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Morzaria-Luna, Hem Nalini; Ainsworth, Cameron H; Kaplan, Isaac C; Levin, Phillip S; Fulton, Elizabeth A</p> <p>2013-01-01</p> <p>High bycatch of non-target species and species of conservation concern often drives the implementation of fisheries policies. However, species- or fishery-specific policies may lead to indirect consequences, positive or negative, for other species or fisheries. We use an Atlantis <span class="hlt">ecosystem</span> model of the Northern Gulf of <span class="hlt">California</span> to evaluate the effects of fisheries policies directed at reducing bycatch of vaquita (Phocoena sinus) on other species of conservation concern, priority target species, and metrics of <span class="hlt">ecosystem</span> function and structure. Vaquita, a Critically Endangered porpoise endemic to the Upper Gulf of <span class="hlt">California</span>, are frequently entangled by finfish gillnets and shrimp driftnets. We tested five fishery management scenarios, projected over 30 years (2008 to 2038), directed at vaquita conservation. The scenarios consider progressively larger spatial restrictions for finfish gillnets and shrimp driftnets. The most restrictive scenario resulted in the highest biomass of species of conservation concern; the scenario without any conservation measures in place resulted in the lowest. Vaquita experienced the largest population increase of any functional group; their biomass increased 2.7 times relative to initial (2008) levels under the most restrictive spatial closure scenario. Bycatch of sea lions, sea turtles, and totoaba decreased > 80% in shrimp driftnets and at least 20% in finfish gillnet fleets under spatial management. We found indirect effects on species and <span class="hlt">ecosystem</span> function and structure as a result of vaquita management actions. Biomass and catch of forage fish declined, which could affect lower-trophic level fisheries, while other species such as skates, rays, and sharks increased in both biomass and catch. When comparing across performance metrics, we found that scenarios that increased <span class="hlt">ecosystem</span> function and structure resulted in lower economic performance indicators, underscoring the need for management actions that consider ecological and economic tradeoffs as part of the integrated management of the Upper Gulf of <span class="hlt">California</span>. PMID:23691155</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3654961','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3654961"><span id="translatedtitle">Indirect Effects of Conservation Policies on the Coupled Human-Natural <span class="hlt">Ecosystem</span> of the Upper Gulf of <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Morzaria-Luna, Hem Nalini; Ainsworth, Cameron H.; Kaplan, Isaac C.; Levin, Phillip S.; Fulton, Elizabeth A.</p> <p>2013-01-01</p> <p>High bycatch of non-target species and species of conservation concern often drives the implementation of fisheries policies. However, species- or fishery-specific policies may lead to indirect consequences, positive or negative, for other species or fisheries. We use an Atlantis <span class="hlt">ecosystem</span> model of the Northern Gulf of <span class="hlt">California</span> to evaluate the effects of fisheries policies directed at reducing bycatch of vaquita (Phocoena sinus) on other species of conservation concern, priority target species, and metrics of <span class="hlt">ecosystem</span> function and structure. Vaquita, a Critically Endangered porpoise endemic to the Upper Gulf of <span class="hlt">California</span>, are frequently entangled by finfish gillnets and shrimp driftnets. We tested five fishery management scenarios, projected over 30 years (2008 to 2038), directed at vaquita conservation. The scenarios consider progressively larger spatial restrictions for finfish gillnets and shrimp driftnets. The most restrictive scenario resulted in the highest biomass of species of conservation concern; the scenario without any conservation measures in place resulted in the lowest. Vaquita experienced the largest population increase of any functional group; their biomass increased 2.7 times relative to initial (2008) levels under the most restrictive spatial closure scenario. Bycatch of sea lions, sea turtles, and totoaba decreased > 80% in shrimp driftnets and at least 20% in finfish gillnet fleets under spatial management. We found indirect effects on species and <span class="hlt">ecosystem</span> function and structure as a result of vaquita management actions. Biomass and catch of forage fish declined, which could affect lower-trophic level fisheries, while other species such as skates, rays, and sharks increased in both biomass and catch. When comparing across performance metrics, we found that scenarios that increased <span class="hlt">ecosystem</span> function and structure resulted in lower economic performance indicators, underscoring the need for management actions that consider ecological and economic tradeoffs as part of the integrated management of the Upper Gulf of <span class="hlt">California</span>. PMID:23691155</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED041076.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED041076.pdf"><span id="translatedtitle">Desegregating <span class="hlt">California</span> Schools. <span class="hlt">California</span> <span class="hlt">Current</span> Review of Human Resources, Number 3, November 1969.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>California League of Women Voters, San Francisco.</p> <p></p> <p>This bulletin, prepared by the League of Women Voters, attempts to summarize popularly used methods of desegregation and to make specific suggestions for use in the State of <span class="hlt">California</span>. State responsibilities for desegregation are presented against the background of Federal and State court decisions. The status of racial imbalance in California…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70111934','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70111934"><span id="translatedtitle">Modeling Hawaiian <span class="hlt">ecosystem</span> degradation due to invasive plants under <span class="hlt">current</span> and future climates</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; `Ohukani`ohi`a Gon, Sam, III; Koob, Gregory A.</p> <p>2014-01-01</p> <p>Occupation of native <span class="hlt">ecosystems</span> by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, <span class="hlt">ecosystem</span> modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive <span class="hlt">ecosystem</span> modifiers, conservation managers could significantly reduce native <span class="hlt">ecosystem</span> degradation. To assess the invasibility of vulnerable native <span class="hlt">ecosystems</span>, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with 0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under <span class="hlt">current</span> climate conditions and, when projected into the future, estimates potential reductions in native <span class="hlt">ecosystem</span> extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated <span class="hlt">ecosystems</span> to the combined threats of climate change and invasive species, and thus help prioritize <span class="hlt">ecosystem</span> and species management actions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41.5942S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41.5942S"><span id="translatedtitle">Application of a data-assimilative regional ocean modeling system for assessing <span class="hlt">California</span> <span class="hlt">Current</span> System ocean conditions, krill, and juvenile rockfish interannual variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schroeder, Isaac D.; Santora, Jarrod A.; Moore, Andrew M.; Edwards, Christopher A.; Fiechter, Jerome; Hazen, Elliott L.; Bograd, Steven J.; Field, John C.; Wells, Brian K.</p> <p>2014-08-01</p> <p>To be robust and informative, marine <span class="hlt">ecosystem</span> models and assessments require parameterized biophysical relationships that rely on realistic water column characteristics at appropriate spatial and temporal scales. We examine how hydrographic properties off <span class="hlt">California</span> from 1990 through 2010 during late winter and spring correspond to krill and juvenile rockfish (Sebastes spp.) abundances. We evaluated coherence among temperature, salinity, depth of 26.0 potential density isopycnal, and stratification strength at regionally and monthly time scales derived from shipboard and mooring observations, and a data-assimilative Regional Ocean Model System reanalysis. The reanalysis captures spatiotemporal physical variability of coastal ocean conditions in winter and spring months and elucidates mechanisms connecting the spatial and temporal upwelling and transport dynamics on observed krill and rockfish abundances in spring. This provides evidence for a mechanistic connection between the phenology of upwelling in the <span class="hlt">California</span> <span class="hlt">Current</span> System and seasonal development of the shelf <span class="hlt">ecosystem</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.B51B0491D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.B51B0491D"><span id="translatedtitle"><span class="hlt">Ecosystem</span> impacts of compost and manure applications to <span class="hlt">California</span> grazed grassland soils</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>DeLonge, M. S.; Silver, W. L.</p> <p>2012-12-01</p> <p>Organic matter amendments, such as compost and manure, are often applied to grasslands to improve soil conditions and enhance net primary productivity. It has been proposed that this land management strategy can sequester carbon (C) in soils and may therefore contribute to climate change mitigation. However, the net mitigation potential of organic amendments depends in part on the <span class="hlt">ecosystem</span> response following land-application, which is likely to vary with the amendment chemical quality (C, N, C:N). To investigate the differences in <span class="hlt">ecosystem</span> response to soil amendments of various qualities, we established research plots on three grazed annual grasslands in northern <span class="hlt">California</span>. The study sites were sampled for soil chemical and physical properties (bulk density, temperature, and moisture), plant community composition, and peak season net primary productivity prior to and following treatment applications. In October 2011, before the rainy season, we applied a thin layer of organic amendments to the study plots. At each site, three replicate plots were treated with fresh manure (1.2 % N, 15.8 % C, C:N = 13.5), three plots were treated with a commercial plant-waste compost (2.4 % N, 26.6 % C, C:N = 11.1), and three plots were left untreated as controls. At one site, 3 additional plots received a thin layer of compost with a lower N concentration and a higher C:N ratio (1.9 % N, 27.4 % C, C:N = 14.5). All plots were sampled for greenhouse gas emissions (N2O, CH4, and CO2, n=3 per plot) using vented chambers shortly after the organic matter was applied, and then intensively following three rain events throughout the rainy season. Results showed that dry amendments were associated with negligible trace gas fluxes, but that these fluxes increased after rain events. Nitrous oxide emissions increased slightly after the first rain event and reached peak levels (approximately 20 ng N cm-1 h-1 for the manure and high N compost only) after three days, following second rain event. The emissions from the high N compost declined more quickly than the manure emissions during the dry-up period. The low N compost exhibited the lowest peak emissions (< 5 ng N cm-1 h-1). Nitrous oxide emissions for all amendments quickly declined and were negligible on both wet and dry days sampled during mid-rainy season. These results suggest that trace gas emissions may not strongly offset the mitigation potential for organic matter amendments. However, differences in the amendment type and quality can influence the offset magnitude. These findings will be presented within the context of other key <span class="hlt">ecosystem</span> characteristics, such as plant community composition, net primary productivity, and soil conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PrOce.120..370B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PrOce.120..370B"><span id="translatedtitle">The central <span class="hlt">California</span> <span class="hlt">Current</span> transition zone: A broad region exhibiting evidence for iron limitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Biller, Dondra V.; Bruland, Kenneth W.</p> <p>2014-01-01</p> <p>The transition zone (TZ) of the central <span class="hlt">California</span> <span class="hlt">Current</span> upwelling system (cCCS) is the boundary between the cold, saline, coastally upwelled water and the warm, less saline, oligotrophic waters of the offshore <span class="hlt">California</span> <span class="hlt">Current</span> (CC). The TZ is a broad region that regularly exhibits chlorophyll concentrations of 1-2 ?g L-1 throughout the spring, summer, and fall seasons. Surface transect and vertical profile data from three cruises (May 2010, June 1999, and August 2011) between 34 and 42N show residual nitrate concentrations (5-15 ?M) and low Fe concentrations (most < 0.2 nmol kg-1) in the TZ. We therefore suggest that much of the TZ of the cCCS is an Fe-limited, high nutrient, lower than expected chlorophyll (HNLC) region. The main source of Fe to the cCCS is from upwelling through the benthic boundary layer (BBL) over the continental shelf sediments. Iron and NO3- in coastally upwelled water are transported via offshore moving filaments into the TZ. However, since some coastal upwelling regions with narrow continental shelves do not have much Fe to begin with, and since Fe is drawn down more rapidly relative to NO3- due to biological assimilation and scavenging, these filaments transport low concentrations of Fe relative to NO3- into the TZ. Weak wind curl-induced upwelling and vertical mixing in the TZ also deliver Fe and NO3- to the surface but at lower concentrations (and lower Fe :NO3-) than from strong coastal upwelling. Mesoscale cyclonic eddies in the TZ are important to consider with respect to offshore surface nutrient delivery because there is a marked shoaling of isopycnals and the nutricline within these eddies allowing higher nutrient concentrations to be closer to the surface. Since wind curl-induced upwelling and/or vertical mixing occurs seaward of the continental shelf, there is not enough Fe delivered to the surface to accompany the NO3-. By using Fe :NO3- ratios and calculated specific growth rates for diatoms, we demonstrate that the TZ of the cCCS shows evidence for Fe limitation of diatom blooms. The TZ also appears to progress further into Fe limitation as the upwelling season progresses from spring into late summer. This study provides some of the first field data to suggest that Fe is a critical bottom up control on the <span class="hlt">ecosystem</span> in the TZ of the cCCS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002DSRI...49..437B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002DSRI...49..437B"><span id="translatedtitle">Integrated biochemical, molecular genetic, and bioacoustical analysis of mesoscale variability of the euphausiid Nematoscelis difficilis in the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bucklin, Ann; Wiebe, Peter H.; Smolenack, Sara B.; Copley, Nancy J.; Clarke, M. Elizabeth</p> <p>2002-03-01</p> <p>Integrated assessment of the euphausiid Nematoscelis difficilis (Crustacea; Euphausiacea) and the zooplankton assemblage of the <span class="hlt">California</span> <span class="hlt">Current</span> was designed to investigate individual, population, and community responses to mesoscale variability in biological and physical characters of the ocean. Zooplankton samples and observational data were collected along a cross-shelf transect of the <span class="hlt">California</span> <span class="hlt">Current</span> in association with the <span class="hlt">California</span> Cooperative Fisheries Investigations (CalCOFI) Survey during October 1996. The transect crossed three domains defined by temperature and salinity: nearshore, mid-<span class="hlt">Current</span>, and offshore. Individual N. difficilis differed in physiological condition along the transect, with higher size-corrected concentrations of four central metabolic enzymes (citrate synthetase, hexokinase, lactate dehydrogenase (LDH), and phosphoglucose isomerase (PGI)) for euphausiids collected in nearshore waters than in mid-<span class="hlt">Current</span> and offshore waters. There was little variation in the DNA sequences of the genes encoding PGI and LDH (all DNA changes were either silent or heterozygous base substitutions), suggesting that differences in enzyme concentration did not result from underlying molecular genetic variation. The population genetic makeup of N. difficilis varied from sample to sample based on haplotype frequencies of mitochondrial cytochrome oxidase I (mtCOI; P=0.029). There were significant differences between pooled nearshore and offshore samples, based on allele frequencies at two sites of common substitutions in the mtCOI sequence ( P=0.020 and 0.026). Silhouette and bioacoustical backscattering measurements of the zooplankton assemblage of the top 100 m showed marked diel vertical migration of the scattering layer, of which euphausiids were a small but significant fraction. The biochemical and molecular assays are used as indices of complex physiological (i.e., growth and condition) and genetic (i.e., mortality) processes; the bioacoustical observations provide insight into the <span class="hlt">ecosystem</span> context for the single-species measurements. All data are intended for integration into predictive models of secondary production and biomass concentration in the ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510243V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510243V"><span id="translatedtitle"><span class="hlt">Current</span> net <span class="hlt">ecosystem</span> exchange of CO2 in a young mixed forest: any heritage from the previous <span class="hlt">ecosystem</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Violette, Aurlie; Heinesch, Bernard; Erpicum, Michel; Carnol, Monique; Aubinet, Marc; Franois, Louis</p> <p>2013-04-01</p> <p>For 15 years, networks of flux towers have been developed to determine accurate carbon balance with the eddy-covariance method and determine if forests are sink or source of carbon. However, for prediction of the evolution of carbon cycle and climate, major uncertainties remain on the <span class="hlt">ecosystem</span> respiration (Reco, which includes the respiration of above ground part of trees, roots respiration and mineralization of the soil organic matter), the gross primary productivity (GPP) and their difference, the net <span class="hlt">ecosystem</span> exchange (NEE) of forests. These uncertainties are consequences of spatial and inter-annual variability, driven by previous and <span class="hlt">current</span> climatic conditions, as well as by the particular history of the site (management, diseases, etc.). In this study we focus on the carbon cycle in two mixed forests in the Belgian Ardennes. The first site, Vielsalm, is a mature stand mostly composed of beeches (Fagus sylvatica) and douglas fir (Pseudotsuga menziesii) from 80 to 100 years old. The second site, La Robinette, was covered before 1995 with spruces. After an important windfall and a clear cutting, the site was replanted, between 1995 and 2000, with spruces (Piceas abies) and deciduous species (mostly Betula pendula, Aulnus glutinosa and Salix aurita). The challenge here is to highlight how initial conditions can influence the <span class="hlt">current</span> behavior of the carbon cycle in a growing stand compared to a mature one, where initial conditions are supposed to be forgotten. A modeling approach suits particularly well for sensitivity tests and estimation of the temporal lag between an event and the <span class="hlt">ecosystem</span> response. We use the forest <span class="hlt">ecosystem</span> model ASPECTS (Rasse et al., Ecological Modelling 141, 35-52, 2001). This model predicts long-term forest growth by calculating, over time, hourly NEE. It was developed and already validated on the Vielsalm forest. Modelling results are confronted to eddy-covariance data on both sites from 2006 to 2011. The main difference between both sites seems to rely on soil respiration, which is probably partly a heritage of the previous <span class="hlt">ecosystem</span> at the young forest site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21506810','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21506810"><span id="translatedtitle">Population structure of three species of Anisakis nematodes recovered from Pacific sardines (Sardinops sagax) distributed throughout the <span class="hlt">California</span> <span class="hlt">Current</span> system.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Baldwin, Rebecca E; Rew, Mary Beth; Johansson, Mattias L; Banks, Michael A; Jacobson, Kym C</p> <p>2011-08-01</p> <p>Members of the Anisakidae are known to infect over 200 pelagic fish species and have been frequently used as biological tags to identify fish populations. Despite information on the global distribution of Anisakis species, there is little information on the genetic diversity and population structure of this genus, which could be useful in assessing the stock structure of their fish hosts. From 2005 through 2008, 148 larval anisakids were recovered from Pacific sardine (Sardinops sagax) in the <span class="hlt">California</span> <span class="hlt">Current</span> upwelling zone and were genetically sequenced. Sardines were captured off Vancouver Island, British Columbia in the north to San Diego, <span class="hlt">California</span> in the south. Three species, Anisakis pegreffii, Anisakis simplex 'C', and Anisakis simplex s.s., were identified with the use of sequences from the internal transcribed spacers (ITS1 and ITS2) and the 5.8s subunit of the nuclear ribosomal DNA. The degree of nematode population structure was assessed with the use of the cytochrome c oxidase 2 (cox2) mitochondrial DNA gene. All 3 Anisakis species were distributed throughout the study region from 32N to 50N latitude. There was no association between sardine length and either nematode infection intensity or Anisakis species recovered. Larval Anisakis species and mitochondrial haplotype distributions from both parsimony networks and analyses of molecular variance revealed a panmictic distribution of these parasites, which infect sardines throughout the <span class="hlt">California</span> <span class="hlt">Current</span> <span class="hlt">ecosystem</span>. Panmictic distribution of the larval Anisakis spp. populations may be a result of the presumed migratory pathways of the intermediate host (the Pacific sardine), moving into the northern portion of the <span class="hlt">California</span> <span class="hlt">Current</span> in summer and returning to the southern portion to overwinter and spawn in spring. However, the wider geographic range of paratenic (large piscine predators), and final hosts (cetaceans) can also explain the observed distribution pattern. As a result, the recovery of 3 Anisakis species and a panmictic distribution of their haplotypes could not be used to confirm or deny the presence of population subdivision of Pacific sardines in the <span class="hlt">California</span> <span class="hlt">Current</span> system. PMID:21506810</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2889511','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2889511"><span id="translatedtitle">Responses of terrestrial <span class="hlt">ecosystems</span> and carbon budgets to <span class="hlt">current</span> and future environmental variability</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Medvigy, David; Wofsy, Steven C.; Munger, J. William; Moorcroft, Paul R.</p> <p>2010-01-01</p> <p>We assess the significance of high-frequency variability of environmental parameters (sunlight, precipitation, temperature) for the structure and function of terrestrial <span class="hlt">ecosystems</span> under <span class="hlt">current</span> and future climate. We examine the influence of hourly, daily, and monthly variance using the <span class="hlt">Ecosystem</span> Demography model version 2 in conjunction with the long-term record of carbon fluxes measured at Harvard Forest. We find that fluctuations of sunlight and precipitation are strongly and nonlinearly coupled to <span class="hlt">ecosystem</span> function, with effects that accumulate through annual and decadal timescales. Increasing variability in sunlight and precipitation leads to lower rates of carbon sequestration and favors broad-leaved deciduous trees over conifers. Temperature variability has only minor impacts by comparison. We also find that projected changes in sunlight and precipitation variability have important implications for carbon storage and <span class="hlt">ecosystem</span> structure and composition. Based on Intergovernmental Panel on Climate Change model estimates for changes in high-frequency meteorological variability over the next 100 years, we expect that terrestrial <span class="hlt">ecosystems</span> will be affected by changes in variability almost as much as by changes in mean climate. We conclude that terrestrial <span class="hlt">ecosystems</span> are highly sensitive to high-frequency meteorological variability, and that accurate knowledge of the statistics of this variability is essential for realistic predictions of <span class="hlt">ecosystem</span> structure and functioning. PMID:20404190</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5180684','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5180684"><span id="translatedtitle">Benthic production and processes off Baja <span class="hlt">California</span>, northwest Africa and Peru: a classification of benthic subsystems in upwelling <span class="hlt">ecosystems</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rowe, G.T.</p> <p>1983-01-01</p> <p>Estimates of the standing stocks, secondary production and metabolism of the benthos have been compared in the coastal upwelling <span class="hlt">ecosystems</span> off northwest Africa, Baja <span class="hlt">California</span>, and southern Peru. Northwest Africa is characterized by shelf break upwelling and as a result standing stocks, macrobenthic production and sediment organic matter are highest out at the shelf-slope boundary. Sediment microbial activity and biomass on the other hand are highest nearshore in the dynamic zone where aeolian silt and sand are being blown into the sea from the Sahara Desert. Baja <span class="hlt">California</span> is dominated by the red crab, Pleuroncodes planipes, having high rates of growth and metabolic utilization of organic matter, both on bottom and in the water. Peru benthos and metabolism are very different from the above areas because of the low oxygen concentrations in the bottom water. Organic matter is far higher in the sediment and heterotrophic metabolism is principally anaerobic rather than aerobic. A normal offshore benthic fauna is replaced by a mat of sulfur bacteria with unknown production and metabolic rates. Benthic subsystems in upwelling <span class="hlt">ecosystems</span> can be placed in two categories: those overloaded with organic matter, depleted of oxygen and dominated by sulfate reduction and those that are not overloaded and remain aerobic. Peru and southwest Africa typify overloaded systems whereas NW Africa and Baja <span class="hlt">California</span> are examples of aerobic systems. Although benthic metabolism and ionorganic nutrient regeneration are high in both types of subsystems, all upwelling <span class="hlt">ecosystems</span>, with their dynamic open boundaries, export organic particulate matter and import inorganic nutrients at rates that are far in excess of that consumed or produced by benthic metabolism. 42 refs., 7 figs., 8 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PrOce..83...15H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PrOce..83...15H"><span id="translatedtitle">The Benguela <span class="hlt">Current</span>: An <span class="hlt">ecosystem</span> of four components</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hutchings, L.; van der Lingen, C. D.; Shannon, L. J.; Crawford, R. J. M.; Verheye, H. M. S.; Bartholomae, C. H.; van der Plas, A. K.; Louw, D.; Kreiner, A.; Ostrowski, M.; Fidel, Q.; Barlow, R. G.; Lamont, T.; Coetzee, J.; Shillington, F.; Veitch, J.; Currie, J. C.; Monteiro, P. M. S.</p> <p>2009-12-01</p> <p>The Benguela system is one of the four major eastern boundary upwelling systems of the world. It is unusual as there are two stratified subtropical or warm temperate boundary regions, on either side of the major wind-driven upwelling region(19-34°S), which itself is subdivided at 26°S by the powerful Luderitz upwelling cell. Important biological components cross the boundary areas at different stages to complete the life-history cycle. While the “Bakun triad” of factors responsible for the development of large pelagic fish populations (enrichment, concentration and retention) provide an important unifying principle for understanding the compromise implicit in adaptation to upwelling systems, the role of predation has been neglected, as has the fish yield relative to photosynthesis. The role global climate change will have in the Benguela in terms of shifting boundaries or weakening or intensifying gradients is being explored. The interannual and decadal signals are so strong in the region that long term trends are difficult to distinguish. Intensive resource utilisation and the collapse of several fish stocks occurred in the Benguela region during the 1960s and 1970s, with different recovery trajectories in the north and the south. The Angolan subsystem can be described as a subtropical transition zone between the wind-driven upwelling system and the Equatorial Atlantic, with gentle upwelling-favourable winds, well-defined seasons, intermediate productivity and moderate, declining fisheries. It is separated from the Namibian subsystem by the Angola-Benguela front. The northern Benguela shelf is a typical coastal upwelling system with equatorward winds, cool water, high plankton biomass and moderate to high fish biomass, which is <span class="hlt">currently</span> in a depleted state. A shift from sardines to horse mackerel occurred during the period 1970-1990, while hake have never fully recovered from intensive fishing pressure up to 1990. Widespread oxygen-depleted waters and sulphur eruptions result from local and remote forcing, restricting the habitat available for pelagic and demersal fish species. The Luderitz-Orange River Cone is an intensive perennial upwelling cell where strong winds, high turbulence and strong offshore transport constitute a partial barrier to epipelagic fish species. Upwelling source water alters in salinity and oxygen, across this boundary zone. A decline in upwelling-favourable winds occurred between 1990 and 2005. The southern Benguela region is characterised by a pulsed, seasonal, wind-driven upwelling at discrete centres and warm Agulhas water offshore. High primary productivity forms a belt of enrichment along the coast, constrained by a front. Low-oxygen water, which only occurs close inshore, may adversely affect some resources. The west coast is primarily a nursery ground for several fish species which spawn on the Agulhas Bank and are transported by alongshore jet <span class="hlt">currents</span> to the west coast. The Agulhas Bank forms the southern boundary of the Benguela system and it displays characteristics of both an upwelling and a temperate shallow shelf system, with seasonal stratification and mixing, coastal, shelf-edge and dynamic upwelling, moderate productivity and a well oxygenated shelf. A large biomass of fish occupies the Bank during the summer season, with some evidence for tight coupling between trophic levels. A cool ridge of upwelled water, with links to coastal upwelling and to the Agulhas <span class="hlt">Current</span>, appears to play an important but poorly understood role affecting the distribution and productivity of pelagic fish. A boom in sardine and anchovy populations was accompanied by an eastward shift, followed by 5 years of poor recruitment by sardine but successful recruitment of anchovy, indicating changes in the early life-history patterns of these two species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991EOSTr..72..209B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991EOSTr..72..209B"><span id="translatedtitle">Underway Doppler <span class="hlt">current</span> profiles in the Gulf of <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Badan-Dangon, Antoine; Lavin, Miguel F.; Hendershott, Myrl C.</p> <p></p> <p>The circulation of the Gulf of <span class="hlt">California</span> has long been of scientific interest. The first hydrographic expedition there was in 1889 [Roden and Groves, 1959], followed half a century later by Sverdrup's cruise on the R/V E.W. Scripps [Suerdrup, 1941] in February and March of 1939. Since then, the Gulfs circulation has been the subject of active research [Alvarez-Boirego, 1983]. During the 1980s, scientists at CICESE and at the Scripps Institution of Oceanography designed a cooperative effort, the Pichicuco project, to investigate some of the notable physical oceanographic features of the Gulf.The Gulf of <span class="hlt">California</span> is a marginal sea close to 1500 km long and about 200 km wide, oriented northwest to southeast, between the peninsula of Baja <span class="hlt">California</span> and western continental Mexico. It consists of a succession of basins that shoal progressively from about 3500 m at the mouth, where the Gulf connects with the Pacific Ocean, to just over 2000 m in the central Guaymas Basin. In contrast, the far northern Gulf is a continental shelf sea whose depth exceeds 200 m only in a few small basins. The Gulf's circulation is profoundly influenced by processes taking place at the narrows that connect Guaymas Basin to the northern Gulf between 28N and 29N (see Figure 1). These are a sequence of channels, each about 15 km wide, between San Lorenzo, San Esteban, and Tiburn islands, which reduce the effective cross section of the Gulf to about 2.25106m2. The westernmost connection, close to Baja <span class="hlt">California</span>, is the Ballenas-Salsipuedes (hereafter Ballenas) channel, whose depth exceeds 1600 m in its central part. It is bounded partially to the north by a lateral constriction with a maximum depth of 600 m, near the northern extreme of Angel de la Guarda island, and to the east by a ridge from which rise Angel de la Guarda, San Lorenzo, and other smaller islands. This ridge extends underwater about 20 km to the southeast from San Lorenzo into Guaymas Basin, where it forms the eastern wall of San Lorenzo sill, the southern end of Ballenas channel. A narrow canyon on this sill has a maximum depth of about 430 m. The central San Esteban channel is located between San Lorenzo and San Esteban islands, and is the deepest and widest of the three. It possesses a single, rather broad sill, formed by a westward underwater extension of San Esteban island. The third channel, between San Esteban and Tiburon islands, is narrower than the first two, has a broad sill at about 300 m depth, and connects the extension of the Sonoran shelf with the deeper basin to the north. Little studied before, it now appears to play a significant role in the regional exchange of water. A fourth, narrow channel between Tiburon island and mainland Mexico is too shallow to participate strongly in the circulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.H51B0483C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.H51B0483C"><span id="translatedtitle">Effects of Debris Flows on Stream <span class="hlt">Ecosystems</span> of the Klamath Mountains, Northern <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cover, M. R.; Delafuente, J. A.; Resh, V. H.</p> <p>2006-12-01</p> <p>We examined the long-term effects of debris flows on channel characteristics and aquatic food webs in steep (0.04-0.06 slope), small (4-6 m wide) streams. A large rain-on-snow storm event in January 1997 resulted in numerous landslides and debris flows throughout many basins in the Klamath Mountains of northern <span class="hlt">California</span>. Debris floods resulted in extensive impacts throughout entire drainage networks, including mobilization of valley floor deposits and removal of vegetation. Comparing 5 streams scoured by debris flows in 1997 and 5 streams that had not been scoured as recently, we determined that debris-flows decreased channel complexity by reducing alluvial step frequency and large woody debris volumes. Unscoured streams had more diverse riparian vegetation, whereas scoured streams were dominated by dense, even-aged stands of white alder (Alnus rhombiflia). Benthic invertebrate shredders, especially nemourid and peltoperlid stoneflies, were more abundant and diverse in unscoured streams, reflecting the more diverse allochthonous resources. Debris flows resulted in increased variability in canopy cover, depending on degree of alder recolonization. Periphyton biomass was higher in unscoured streams, but primary production was greater in the recently scoured streams, suggesting that invertebrate grazers kept algal assemblages in an early successional state. Glossosomatid caddisflies were predominant scrapers in scoured streams; heptageniid mayflies were abundant in unscoured streams. Rainbow trout (Oncorhynchus mykiss) were of similar abundance in scoured and unscoured streams, but scoured streams were dominated by young-of-the-year fish while older juveniles were more abundant in unscoured streams. Differences in the presence of cold-water (Doroneuria) versus warm-water (Calineuria) perlid stoneflies suggest that debris flows have altered stream temperatures. Debris flows have long-lasting impacts on stream communities, primarily through the cascading effects of removal of riparian vegetation. Because debris flow frequency increases following road construction and timber harvest, the long-term biological effects of debris flows on stream <span class="hlt">ecosystems</span>, including anadromous fish populations, needs to be considered in forest management decisions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......409M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......409M"><span id="translatedtitle">Linking Seasonal Foliar Chemistry to VSWIR-TIR Spectroscopy Across <span class="hlt">California</span> <span class="hlt">Ecosystems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meerdink, Susan Kay</p> <p></p> <p>Potential ecological impacts of disturbance, land use, and climate change have driven many studies to evaluate <span class="hlt">ecosystem</span> functions through the measurement of vegetation biochemical properties that provide integral information on nutrient cycling, litter decomposition, and plant productivity. The use of spectroscopy in quantifying vegetation biochemistry shows promise with faster analytical speed than traditional methods. Synergies between the Visible Near Infrared/ Short Wave Infrared (VSWIR) and Thermal Infrared (TIR) spectra for identifying plant species' foliar chemistry have been largely unexplored. Here we evaluate the capability of VSWIR and/or TIR spectra to predict leaf levels of lignin, cellulose, nitrogen, water content, and leaf mass per area. We specifically examined how these predictive relationships might change seasonally and among plant functional types. Lastly we determined whether these relationships between spectra and foliar chemistry could be extended to the reduced spectral resolution available in airborne sensors, including the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), the Hyperspectral Thermal Emission Spectrometer (HyTES), and the combined AVIRIS and MODIS/ASTER (MASTER) sensors used in the Hyperspectral Infrared Imager (HyspIRI) preparatory flight campaign. In the 2013 spring, summer, and fall seasons, fresh leaves from sixteen common shrub and tree species in <span class="hlt">California</span> representing three broad plant functional types were sampled from the Sierra Nevada Mountains, the Central Valley at the Sedgwick Reserve, and coastal Santa Barbara. Partial least squares regression (PLSR) analysis was used to relate spectral response at wavelengths from 0.3 - 15.4 microm to laboratory-measured biochemical and biophysical properties. For each component, three PLSR models were fit using different portions of the spectrum: VSWIR (0.3 - 2.5 microm), TIR (2.5 - 15.4 microm), and the full spectrum (0.3 - 15.4 microm). Three additional models were fitted using spectra resampled to AVIRIS (0.4 - 2.5 microm), HyTES (7.5 - 12 microm), and the combined AVIRIS and MASTER (0.38 - 12 microm). The majority of the highest performing laboratory spectra models used either the TIR or full spectrum. When using simulated sensor spectra, the combined AVIRIS and MASTER produced the highest performing models, followed by HyTES. From both laboratory and sensor simulated model results, the combination of VSWIR and TIR increased the R2 value of regression models compared to VSWIR alone, signifying that the inclusion of TIR data would improve predictions of foliar chemistry. We also found that model precision varied by seasons and across plant functional types. Models developed for all seasons resulted in a decreased R2 value, but still had high precision (R2 > 0.85) and accuracy (RMSE < 10%) when predicting cellulose, nitrogen, and water content. These results indicate that the TIR could augment the VSWIR in advancing identification of leaf properties of the world's <span class="hlt">ecosystems</span> by helping to set the foundation for future use of the full spectrum represented by the proposed HyspIRI space-borne sensor.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24590188','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24590188"><span id="translatedtitle"><span class="hlt">Current</span> developments in groundwater ecology--from biodiversity to <span class="hlt">ecosystem</span> function and services.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Griebler, Christian; Malard, Florian; Lefbure, Tristan</p> <p>2014-06-01</p> <p>Groundwater <span class="hlt">ecosystems</span> constitute the largest terrestrial freshwater biome. They are dark, extremely low in energy and do not provide much space but they contain an unexpectedly high diversity of living forms showing characteristic adaptive features. The restricted accessibility along with the enormous 'invisible' heterogeneity challenged for a long time testing of scientific theories and unraveling of <span class="hlt">ecosystem</span> functioning. Triggered by an improved interdisciplinarity, comprehensive sampling strategies and <span class="hlt">current</span> developments in biotechnology and statistical analysis, groundwater ecology gains momentum entering a new era of research. We are only beginning to understand adaptive mechanisms, species distribution patterns and <span class="hlt">ecosystem</span> functioning. Ninety-five percent of global liquid freshwater is stored in the terrestrial subsurface constituting a major source of water for drinking, irrigation and industrial purposes. There is an urgent need to integrate evolutionary and ecological research for developing a holistic perspective of the functional roles of biodiversity and <span class="hlt">ecosystem</span> services and predicting global changes under alternative groundwater resource use scenarios. PMID:24590188</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMOS31C1736S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMOS31C1736S"><span id="translatedtitle">Decadal changes in the Canary <span class="hlt">Current</span> Upwelling <span class="hlt">Ecosystem</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Santos, A. M.; Luis, J. M.; Relvas-Almeida, P.</p> <p>2013-12-01</p> <p>The Canary <span class="hlt">Current</span> Upwelling System (CCUS) covers the latitudinal range 12-43 degrees N and has some singularities in relation to the other three major Eastern Boundary Upwelling Systems (EBUS), namely a major interruption in the continuity of the system at the Strait of Gibraltar and it is the only one with a sardine species from a different genus (Sardina vs Sardinops). Long-term trends in ocean temperature and coastal upwelling were investigated using the AVHRR Pathfinder SST (sea surface temperature) Version 5.1 dataset, in situ SST from the International Comprehensive Ocean-Atmosphere Data Set (ICOADS), and upwelling indices from the Pacific Fisheries Environmental Laboratory (PFEL). The analysis is applied to the eastern boundary of the North Atlantic, from 10 to 45 degrees N extending until 30 degrees W, focusing mainly in the CCUS because the strong dynamic link between the atmosphere and the ocean makes upwelling regions highly sensitive to global change and ideal to monitor and investigate its effects. The detail in SST variability results in a large extent from the fine analysis and the numerical processing carefully designed to avoid trend bias in the climatological studies. The obtained fields of SST trends show a generalized warming of the entire region. However, alternate patches of significantly different warming rates are observed, ranging from large scale down to mesoscale. Known coastal upwelling features are seen to warm at a lower rate than corresponding offshore waters, pointing to an intensification of the upwelling in the last decades. Wind data are used to attempt to explain the variability of some upwelling structures. Our results evidence the main role that mesoscale processes play in the modulation of the spatial and temporal variability of SST, namely at the decadal scale. This result prevents any global conclusion about the intensification of the upwelling at the scale of the entire CCUS. The bulk of the sardine population is located in the southern part of CCUS off NW Africa. Important fluctuations in landings have been observed in the last 70 years but they seem to be out of phase between the two sub-regions - the northern CCUS (Iberia) and southern CCUS (NW Africa). The explanation for these fluctuations has been related, at least partially, to environmental drivers but also to changes in exploitation. Landing time series of sardine, anchovy and sardinella were used to perform an exploratory analysis to investigate the relationships between small pelagic fish species in the CCUS and decadal changes in SST and coastal upwelling. This is a contribution to FCT (Portuguese Science and Technology Foundation) funded projects LONGUP (PTDC/AAC-CLI/105296/2008) and MODELA (PTDC/MAR/098643/2008).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGC23C0976K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGC23C0976K"><span id="translatedtitle">Assessing Impacts of Climate Variability and Change on the Agro-<span class="hlt">ecosystems</span> in <span class="hlt">California</span> and Southwestern United States</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kafatos, M.; Asrar, G. R.; El-Askary, H. M.; Hatzopoulos, N.; Hayhoe, K.; Kim, J.; Ziska, L.; Medvigy, D.; Prasad, A. K.; Tremback, C.; Walko, R. L.</p> <p>2011-12-01</p> <p>Climate variability and change affects natural and managed <span class="hlt">ecosystems</span>, namely agriculture and rangelands, and the services they offer such as food, fiber, energy, fresh water, etc. we derive from them are among the highest concerns in quantifying the potential consequences of anthropogenic climate change. These impacts are expected to be <span class="hlt">ecosystem</span> and region specific, thus requiring climate information at greater spatial and temporal resolution offered by the global climate models. In this study we are using a combination of climate downscaling and regional climate models in conjunction with <span class="hlt">ecosystem</span> models to assess the impact of climate variability and change on the natural and managed <span class="hlt">ecosystems</span> in <span class="hlt">California</span> and Southwest region of the United States. In an attempt to generate reliable assessments of the impact of regional climate variability and change on the agro-<span class="hlt">ecosystems</span> in the region, we have designed an impact assessment study in which multiple Regional Climate Models (RCMs) are used to develop downscaled climate information to in turn drive <span class="hlt">ecosystem</span> models. We develop the climate scenarios for the region based on a combination of dynamical and statistical approaches. We evaluate the efficacy of the climate scenarios in hindcast mode against available historical observation records to build confidence in their future climate projections. We then use the derived climate information in the <span class="hlt">ecosystem</span> models to assess how these <span class="hlt">ecosystems</span> will function under the projected climate conditions. We will present some early results from the evaluation of three regional climate models in a long-term hindcast experiments, the fundamental step before performing regional climate projection. Model variables needed by agro-<span class="hlt">ecosystem</span> models, daily precipitation and temperature extremes, from individual models and their ensembles, are being evaluated against the National Weather Service observation network and the global gridded analyses from NCEP. We also compare direct RCM simulations with a hybrid dynamical-statistical downscaling approach in order to expand our understanding of the limitations and strengths of various plausible approaches to generating high-resolution climate projections for agroecosystem impact analyses. The combination of Earth observations with model runs provides great opportunities for practical assessment of climate impacts at regional scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JGRC..113.4015K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JGRC..113.4015K"><span id="translatedtitle">Spatial and interannual variability in mesoscale circulation in the northern <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keister, Julie E.; Strub, P. Ted</p> <p>2008-04-01</p> <p>We used wavelet analyses of sea surface height (SSH) from >13 years of satellite altimeter data to characterize the variability in mesoscale circulation in the northern <span class="hlt">California</span> <span class="hlt">Current</span> (35N-49N) and explore the mechanisms of variability. We defined "mesoscale" circulation as features, such as eddies and filaments, which have 50- to 300-km length scales and 4- to 18-week temporal scales. Fluctuations in SSH caused by such features were reflected in wavelet analyses as power (energy). Spatial and interannual variation in mesoscale energy was high. Energy was highest at 38N, decreasing to the north and south. Between 43N and 48N, energy was low. Zonally, mesoscale energy was highest between 125W and 129W at latitudes south of 44N; very little power occurred in the deep ocean west of 130W. Energy peaked during summer/fall in most years. The primary climate signals were suppressed energy during La Nia and cold years and increased energy during El Nio events. Energy was not strongly linked to upwelling winds, but did correspond to climate indices, indicating that basin-scale processes play a role in controlling mesoscale circulation. We hypothesize that climate affects mesoscale energy through changes in both potential and kinetic energy in the form of density gradients and coastal upwelling winds. The relationship between mesoscale circulation and climate was complex: no single climate, transport, or upwelling index explained the variability. These results are relevant to <span class="hlt">ecosystem</span> dynamics and the global carbon cycle because mesoscale circulation features deliver nutrient-rich water and coastal organisms from productive upwelling areas to the deep sea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/1016326','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/1016326"><span id="translatedtitle">Fire and aquatic <span class="hlt">ecosystems</span> of the western USA: <span class="hlt">Current</span> knowledge and key questions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bisson, P.A.; Rieman, B.; Luce, C.; Hessburg, Paul F.; Lee, D.; Kershner, J.; Reeves, G.H.; Gresswell, Robert E.</p> <p>2003-01-01</p> <p>Understanding of the effects of wildland fire and fire management on aquatic and riparian <span class="hlt">ecosystems</span> is an evolving field, with many questions still to be resolved. Limitations of <span class="hlt">current</span> knowledge, and the certainty that fire management will continue, underscore the need to summarize available information. Integrating fire and fuels management with aquatic <span class="hlt">ecosystem</span> conservation begins with recognizing that terrestrial and aquatic <span class="hlt">ecosystems</span> are linked and dynamic, and that fire can play a critical role in maintaining aquatic ecological diversity. To protect aquatic <span class="hlt">ecosystems</span> we argue that it will be important to: (1) accommodate fire-related and other ecological processes that maintain aquatic habitats and biodiversity, and not simply control fires or fuels; (2) prioritize projects according to risks and opportunities for fire control and the protection of aquatic <span class="hlt">ecosystems</span>; and (3) develop new consistency in the management and regulatory process. Ultimately, all natural resource management is uncertain; the role of science is to apply experimental design and hypothesis testing to management applications that affect fire and aquatic <span class="hlt">ecosystems</span>. Policy-makers and the public will benefit from an expanded appreciation of fire ecology that enables them to implement watershed management projects as experiments with hypothesized outcomes, adequate controls, and replication.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4013088','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4013088"><span id="translatedtitle">Modeling Hawaiian <span class="hlt">Ecosystem</span> Degradation due to Invasive Plants under <span class="hlt">Current</span> and Future Climates</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; Gon, Sam 'Ohukani'ohi'a; Koob, Gregory A.</p> <p>2014-01-01</p> <p>Occupation of native <span class="hlt">ecosystems</span> by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, <span class="hlt">ecosystem</span> modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive <span class="hlt">ecosystem</span> modifiers, conservation managers could significantly reduce native <span class="hlt">ecosystem</span> degradation. To assess the invasibility of vulnerable native <span class="hlt">ecosystems</span>, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with <0.7 niche overlap (Warrens I) and relatively discriminative distributions (Area Under the Curve >0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under <span class="hlt">current</span> climate conditions and, when projected into the future, estimates potential reductions in native <span class="hlt">ecosystem</span> extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated <span class="hlt">ecosystems</span> to the combined threats of climate change and invasive species, and thus help prioritize <span class="hlt">ecosystem</span> and species management actions. PMID:24805254</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70019984','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70019984"><span id="translatedtitle">Biogenic sedimentation beneath the <span class="hlt">California</span> <span class="hlt">Current</span> system for the past 30 kyr and its paleoceanographic significance</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gardner, J.V.; Dean, W.E.; Dartnell, P.</p> <p>1997-01-01</p> <p>A north-south transect of 17 cores was constructed along the eastern boundary of the <span class="hlt">California</span> <span class="hlt">Current</span> system from 33?? to 42?? N to investigate the changes in biogenic sedimentation over the past 30 kyr. Percentages and mass accumulation rates of CaCO3, Corg, and biogenic opal were assembled at 500 to 1000 years/sample to provide relatively high resolution. Time-space maps reveal a complex pattern of changes that do not follow a simple glacial-interglacial two-mode model. Biogenic sedimentation shows responses that are sometimes time-transgressive and sometimes coeval, and most of the responses show more consistency within a limited geographic area than any temporal consistency. Reconstructed conditions during late oxygen isotope stage 3 were more like early Holocene conditions than any other time during the last 30 kyr. Coastal upwelling and productivity during oxygen isotope stage 3 were relatively strong along the central <span class="hlt">California</span> margin but were weak along the northern <span class="hlt">California</span> margin. Precipitation increased during the last glacial interval in the central <span class="hlt">California</span> region, and the waters of the southern <span class="hlt">California</span> margin had relatively low productivity. Productivity on the southern Oregon margin was relatively low at the beginning of the last glacial interval, but by about 20 ka, productivity in this area significantly increased. This change suggests that the center of the divergence of the West Wind Drift shifted south at this time. The end of the last glacial interval was characterized by increased productivity in the southern <span class="hlt">California</span> margin and increased upwelling along the central <span class="hlt">California</span> margin but upwelling remained weak along the northern <span class="hlt">California</span> margin. A sudden (<300 years) decrease in CaCO3, Corg, and biogenic opal occurred at 13 ka. The changes suggest a major reorientation of the atmospheric circulation in the North Pacific and western North America and the establishment of a strong seasonality in the central <span class="hlt">California</span> region. A carbonate preservation event occurred at 10 ka that appears to reflect the uptake of CO2 by the terrestrial biosphere as the northern latitudes were reforested following retreat of the glaciers. The Holocene has been a period of relatively high productivity in the southern <span class="hlt">California</span> margin, relatively strong coastal upwelling along the central <span class="hlt">California</span> margin, relatively weak upwelling along the northern <span class="hlt">California</span> margin, and the northward migration of the divergence zone of the West Wind Drift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS31B1710Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS31B1710Y"><span id="translatedtitle">Dynamic connectivity in the Southern <span class="hlt">California</span> Bight and Georges Bank: Identifying <span class="hlt">ecosystem</span> interactions using chaotic time series analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ye, H.; Deyle, E. R.; Hsieh, C.; Sugihara, G.</p> <p>2012-12-01</p> <p>We used convergent cross mapping (CCM), a method grounded in nonlinear dynamical systems theory to analyze long-term time series of fish species from the <span class="hlt">California</span> Cooperative Oceanic Fisheries Investigations ichthyoplankton (isolated to the Southern <span class="hlt">California</span> Bight [SCB]) and NOAA National Marine Fisheries Service Northeast Fisheries Science Center trawl survey (isolated to the Georges Bank [GB] region) data sets. CCM gives a nonparametric indicator of the realized dynamic influence that one species has on another (i.e. how much the abundance of X at a particular time is dependent on the historical abundance of Y). We found there are more interactions between species in SCB compared to GB. An analysis of the interaction matrix showed that there is also more structure in the connectivity network of SCB compared to GB. We attribute this difference in connectivity to historical overexploitation of fish stocks in the North Atlantic, and reproduce this effect in simple multi-species fishery models. We discuss the implications of these results for <span class="hlt">ecosystem</span>-based management and for restoration efforts.; Connectivity Networks for Fishes in the Southern <span class="hlt">California</span> Bight (SCB) and Georges Bank (GB) as determined using cross-mapping.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70135867','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70135867"><span id="translatedtitle">Bottom <span class="hlt">current</span> and sediment transport on San Pedro Shelf, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Drake, David E.; Cacchione, David A.; Karl, Herman A.</p> <p>1985-01-01</p> <p>GEOPROBE (Geological Processes Bottom Environmental) tripods were used to measure bottom <span class="hlt">currents</span>, pressure, and light transmission and scattering and to obtain time-series photographs of the sea floor at depths of 23 m and 67 m on San Pedro shelf between 18 April and 6 June 1978. Winds were light (< 5 m/s) with a mean direction from the southwest throughout the measurement period. Hourly averaged <span class="hlt">currents</span> 1 m above the bottom never exceeded 21 cm/s; average speeds were about 5 cm/s at the 23-m site and 6.8 cm/s at 67 m, and the strongest <span class="hlt">currents</span> were produced by the tides. The mean flow of bottom water was less than 3 cm/s at both GEOPROBES and was rather persistently southward (offshelf). Wave-generated bottom <span class="hlt">currents</span> and bottom-pressure variations were sampled at hourly intervals; average wave period and wave height were 12.8 s and 0.44 m, respectively, at the 23-m site. Wave orbital velocities ranged from about 5 to 30 cm/s at 23 m and from 2 to 8 cm/s at 67 m. Bottom photographs at 67 m show that the relatively sluggish tide-generated and mean <span class="hlt">currents</span> were below threshold velocity for the silty, very fine sand throughout the observational period. Threshold depth for wave rippling of very fine sand averaged about 28 m with a range from about 12 m to 50 m. Wave-generated <span class="hlt">currents</span> were the only <span class="hlt">currents</span> that exceeded threshold levels. The wave <span class="hlt">currents</span> maintained relatively high concentrations of sediment in suspension near the bottom over the inner shelf (< 25 m), and this material (principally silt and clay) was transported offshore by the weak mean flow. Approximately 50% of this material was deposited as the bottom orbital velocities decreased to subthreshold values ( nearly equal 10-15 cm/s). The observed movement of fine sediment across the inner shelf can account for a portion of the mud content of the modern silty sands on the central shelf and on the outer shelf. However, it is clear that the sand fractions, which constitute greater than 70% of the central shelf substrate, must be transported during high-energy winter storms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=309504&keyword=economics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=55650241&CFTOKEN=41428020','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=309504&keyword=economics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=55650241&CFTOKEN=41428020"><span id="translatedtitle">Quantitative Models Describing Past and <span class="hlt">Current</span> Nutrient Fluxes and Associated <span class="hlt">Ecosystem</span> Level Responses in the Narragansett Bay <span class="hlt">Ecosystem</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Multiple drivers, including nutrient loading and climate change, affect the Narragansett Bay <span class="hlt">ecosystem</span> in Rhode Island/Massachusetts, USA. Managers are interested in understanding the timing and magnitude of these effects, and <span class="hlt">ecosystem</span> responses to restoration actions. To provid...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=222525','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=222525"><span id="translatedtitle">Fine root production across a primary successional <span class="hlt">ecosystem</span> chronosequence at Mt. Shasta, <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Estimating changes in belowground biomass and production is essential for understanding fundamental patterns and processes during <span class="hlt">ecosystem</span> development. We examined patterns of fine root production, aboveground litterfall, and forest floor accumulation during forest primary succession at the Mt. Sha...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24324585','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24324585"><span id="translatedtitle">Cumulative human impacts on Mediterranean and Black Sea marine <span class="hlt">ecosystems</span>: assessing <span class="hlt">current</span> pressures and opportunities.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Micheli, Fiorenza; Halpern, Benjamin S; Walbridge, Shaun; Ciriaco, Saul; Ferretti, Francesco; Fraschetti, Simonetta; Lewison, Rebecca; Nykjaer, Leo; Rosenberg, Andrew A</p> <p>2013-01-01</p> <p>Management of marine <span class="hlt">ecosystems</span> requires spatial information on <span class="hlt">current</span> impacts. In several marine regions, including the Mediterranean and Black Sea, legal mandates and agreements to implement <span class="hlt">ecosystem</span>-based management and spatial plans provide new opportunities to balance uses and protection of marine <span class="hlt">ecosystems</span>. Analyses of the intensity and distribution of cumulative impacts of human activities directly connected to the ecological goals of these policy efforts are critically needed. Quantification and mapping of the cumulative impact of 22 drivers to 17 marine <span class="hlt">ecosystems</span> reveals that 20% of the entire basin and 60-99% of the territorial waters of EU member states are heavily impacted, with high human impact occurring in all ecoregions and territorial waters. Less than 1% of these regions are relatively unaffected. This high impact results from multiple drivers, rather than one individual use or stressor, with climatic drivers (increasing temperature and UV, and acidification), demersal fishing, ship traffic, and, in coastal areas, pollution from land accounting for a majority of cumulative impacts. These results show that coordinated management of key areas and activities could significantly improve the condition of these marine <span class="hlt">ecosystems</span>. PMID:24324585</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3850916','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3850916"><span id="translatedtitle">Cumulative Human Impacts on Mediterranean and Black Sea Marine <span class="hlt">Ecosystems</span>: Assessing <span class="hlt">Current</span> Pressures and Opportunities</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Micheli, Fiorenza; Halpern, Benjamin S.; Walbridge, Shaun; Ciriaco, Saul; Ferretti, Francesco; Fraschetti, Simonetta; Lewison, Rebecca; Nykjaer, Leo; Rosenberg, Andrew A.</p> <p>2013-01-01</p> <p>Management of marine <span class="hlt">ecosystems</span> requires spatial information on <span class="hlt">current</span> impacts. In several marine regions, including the Mediterranean and Black Sea, legal mandates and agreements to implement <span class="hlt">ecosystem</span>-based management and spatial plans provide new opportunities to balance uses and protection of marine <span class="hlt">ecosystems</span>. Analyses of the intensity and distribution of cumulative impacts of human activities directly connected to the ecological goals of these policy efforts are critically needed. Quantification and mapping of the cumulative impact of 22 drivers to 17 marine <span class="hlt">ecosystems</span> reveals that 20% of the entire basin and 60–99% of the territorial waters of EU member states are heavily impacted, with high human impact occurring in all ecoregions and territorial waters. Less than 1% of these regions are relatively unaffected. This high impact results from multiple drivers, rather than one individual use or stressor, with climatic drivers (increasing temperature and UV, and acidification), demersal fishing, ship traffic, and, in coastal areas, pollution from land accounting for a majority of cumulative impacts. These results show that coordinated management of key areas and activities could significantly improve the condition of these marine <span class="hlt">ecosystems</span>. PMID:24324585</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060032980&hterms=reintroductions&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dreintroductions','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060032980&hterms=reintroductions&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dreintroductions"><span id="translatedtitle">The State of the <span class="hlt">California</span> <span class="hlt">Current</span> in 1999-2000: Forward to a New Regime?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>DiGiacomo, P.</p> <p>2000-01-01</p> <p>Following an extended absence, the reintroduction of ocean color sensors to space in the mid to late 1990's provided an invaluable opportunity for evaluating the biological impact of the 1997-99 El Nino/La Nina events in the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMGC11A0972P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMGC11A0972P"><span id="translatedtitle">Using sensitive montane amphibian species as indicators of hydroclimatic change in meadow <span class="hlt">ecosystems</span> of the Sierra Nevada, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peek, R.; Viers, J.; Yarnell, S. M.</p> <p>2012-12-01</p> <p>Climate change can affect sensitive species and <span class="hlt">ecosystems</span> in many ways, yet sparse data and the inability to apply various climate models at functional spatial scales often prevents relevant research from being utilized in conservation management plans. Climate change has been linked to declines and disturbances in a multitude of species and habitats, and in <span class="hlt">California</span>, one of the greatest climatic concerns is the predicted reduction in mountain snowpack and associated snowmelt. These decreases in natural storage of water as snow in mountain regions can affect the timing and variability of critical snowmelt runoff periods—important seasonal signals that species in montane <span class="hlt">ecosystems</span> have evolved life history strategies around—leading to greater intra-annual variability and diminished summer and fall stream flows. Although many species distribution models exist, few provide ways to integrate continually updated and revised Global Climate Models (GCMs), hydrologic data unique to a watershed, and ecological responses that can be incorporated into conservation strategies. This study documents a novel and applicable method of combining boosted regression tree (BRT) modeling and species distributions with hydroclimatic data as a potential management tool for conservation. Boosted regression trees are suitable for ecological distribution modeling because they can reduce both bias and variance, as well as handle sharp discontinuities common in sparsely sampled species or large study areas. This approach was used to quantify the effects of hydroclimatic changes on the distribution of key riparian-associated amphibian species in montane meadow habitats in the Sierra Nevada at the sub-watershed level. Based on modeling using <span class="hlt">current</span> species range maps in conjunction with three climate scenarios (near, mid, and far), extreme range contractions were observed for all sensitive species (southern long-toed salamander, mountain yellow-legged frog, Yosemite toad) by the year 2100. Among many environmental and hydroclimatic variables used in the model, snowpack and snowmelt (runoff) variables were consistently among the most informative in predicting species occupancy. Few sub-watersheds contained greater than 50% probability of species occupancy throughout the modeled time period; however several core areas were identified as more resilient to climate change for each species. There was overlap among species in areas that were predicted to remain hydroclimatically stable, particularly in sub-watersheds that contain high meadow density. Quantifying these areas of habitat stability, or "resiliency", may ultimately be the most useful outcome of BRT modeling, with the flexibility to utilize multiple GCMs at varying scales. Ultimately managers need to consider both short term and long term conservation goals by identifying and protecting suitable habitat areas most resilient to climate change to give multiple species the best chance to persist. This approach provides a unique tool for conservation management which can be easily applied to a variety of data and species, and provides useful knowledge at both near and long term time scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JMS...109..149L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JMS...109..149L"><span id="translatedtitle">Response of biological production and air-sea CO2 fluxes to upwelling intensification in the <span class="hlt">California</span> and Canary <span class="hlt">Current</span> Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lachkar, Zouhair; Gruber, Nicolas</p> <p>2013-01-01</p> <p>Upwelling-favorable winds have increased in most Eastern Boundary Upwelling Systems (EBUS) in the last decades, and it is likely that they increase further in response to global climate change. Here, we explore the response of biological production and air-sea CO2 fluxes to upwelling intensification in two of the four major EBUS, namely the <span class="hlt">California</span> <span class="hlt">Current</span> System (<span class="hlt">California</span> CS) and Canary <span class="hlt">Current</span> System (Canary CS). To this end, we use eddy-resolving regional ocean models on the basis of the Regional Oceanic Modeling System (ROMS) to which we have coupled a NPZD-type <span class="hlt">ecosystem</span> model and a biogeochemistry module describing the carbon cycle and subject these model configurations to an idealized increase in the wind stress. We find that a doubling of the wind-stress doubles net primary production (NPP) in the southern <span class="hlt">California</span> CS and central and northern Canary CS, while it leads to an increase of less than 50% in the central and northern <span class="hlt">California</span> CS as well as in the southern Canary CS. This differential response is a result of i) different nutrient limitation states with higher sensitivity to upwelling intensification in regions where nutrient limitation is stronger and ii) more efficient nutrient assimilation by biology in the Canary CS relative to the <span class="hlt">California</span> CS because of a faster nutrient-replete growth rate and longer nearshore water residence times. In the regions where production increases commensurably with upwelling intensification, the enhanced net biological uptake of CO2 compensates the increase in upwelling driven CO2 outgassing, resulting in only a small change in the biological pump efficiency and hence in a small sensitivity of air-sea CO2 fluxes to upwelling intensification. In contrast, in the central <span class="hlt">California</span> CS as well as in the southern Canary CS around Cape Blanc, the reduced biological efficiency enhances the CO2 outgassing and leads to a substantial sensitivity of the air-sea CO2 fluxes to upwelling intensification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMPP33A2092M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMPP33A2092M"><span id="translatedtitle">Hypoxia in high-resolution sediment records: reconstructing the <span class="hlt">California</span> <span class="hlt">Current</span> Oxygen Minimum Zone on multi-decadal timescales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moffitt, S. E.; Hill, T. M.</p> <p>2012-12-01</p> <p>The recent deglaciation event is an ideal laboratory to study the rapid expansion of Oxygen Minimum Zones (OMZs) and the ecological ramifications of such events. Santa Barbara Basin (SBB) sediments are high-resolution archives of seafloor <span class="hlt">ecosystems</span>, recording both global-scale climate and regional-scale hydrographic events. Seafloor hypoxia in the <span class="hlt">California</span> <span class="hlt">Current</span> <span class="hlt">Ecosystem</span> (CCE) is caused by OMZs in intermediate water depths (300-1200 m), and produces striking evidence in SBB sediment archives. We construct a vertical transect of proxies across SBB (34 15'N, 119 45'W) using a core from 418 m water depth (MV0811-15JC), and previously investigated cores from 440 m (MD02-2504) and 570 m (MD02-2503) water depths. Benthic foraminiferal assemblages and planktonic ?18O proxies were quantified at all three depths, while benthic invertebrate communities were quantified in the shallowest core at a 1-cm resolution (~10 years). This high-resolution invertebrate record provides a window into rapid, decadal-scale environmental change in continental margin <span class="hlt">ecosystems</span>. Seafloor biodiversity is highly variable on 10-10^4 year timescales (across Protist, Mollusc, Arthropod and Echinoderm taxonomic groups), and is tightly coupled to both regional-scale environmental change and global-scale climate events. Additionally, we provide evidence that strongly hypoxic waters shoaled to <300 m water depth at Termination 1A (14.7 ka), implying that the upper boundary of the regional OMZ can expand >150 m on multi-decadal timescales. These data confirm that OMZs have rapidly expanded in the CCE during previous events of global-scale warming, and that continental margin seafloor biodiversity is variable on previously undescribed timescales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=59617&keyword=mosquito&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=58647334&CFTOKEN=75915729','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=59617&keyword=mosquito&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=58647334&CFTOKEN=75915729"><span id="translatedtitle">ORGANIC POLLUTANT DEPOSITION TO THE SIERRA NEVADA (<span class="hlt">CALIFORNIA</span>, USA) SNOWPACK AND ASSOCIATED LAKE AND STREAM <span class="hlt">ECOSYSTEM</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>High elevation <span class="hlt">ecosystems</span> in the western USA and Canada are receiving deposition of persistent organic pollutants (POPs) that presumably originate in the USA as well as outside its borders. In April 1992 we obtained paired snowpack samples from each of two watersheds located in t...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25379790','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25379790"><span id="translatedtitle">Positive effects of non-native grasses on the growth of a native annual in a southern <span class="hlt">california</span> <span class="hlt">ecosystem</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pec, Gregory J; Carlton, Gary C</p> <p>2014-01-01</p> <p>Fire disturbance is considered a major factor in the promotion of non-native plant species. Non-native grasses are adapted to fire and can alter environmental conditions and reduce resource availability in native coastal sage scrub and chaparral communities of southern <span class="hlt">California</span>. In these communities persistence of non-native grasses following fire can inhibit establishment and growth of woody species. This may allow certain native herbaceous species to colonize and persist beneath gaps in the canopy. A field manipulative experiment with control, litter, and bare ground treatments was used to examine the impact of non-native grasses on growth and establishment of a native herbaceous species, Cryptantha muricata. C. muricata seedling survival, growth, and reproduction were greatest in the control treatment where non-native grasses were present. C. muricata plants growing in the presence of non-native grasses produced more than twice the number of flowers and more than twice the reproductive biomass of plants growing in the treatments where non-native grasses were removed. Total biomass and number of fruits were also greater in the plants growing in the presence of non-native grasses. Total biomass and reproductive biomass was also greater in late germinants than early germinants growing in the presence of non-native grasses. This study suggests a potential positive effect of non-native grasses on the performance of a particular native annual in a southern <span class="hlt">California</span> <span class="hlt">ecosystem</span>. PMID:25379790</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4224496','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4224496"><span id="translatedtitle">Positive Effects of Non-Native Grasses on the Growth of a Native Annual in a Southern <span class="hlt">California</span> <span class="hlt">Ecosystem</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pec, Gregory J.; Carlton, Gary C.</p> <p>2014-01-01</p> <p>Fire disturbance is considered a major factor in the promotion of non-native plant species. Non-native grasses are adapted to fire and can alter environmental conditions and reduce resource availability in native coastal sage scrub and chaparral communities of southern <span class="hlt">California</span>. In these communities persistence of non-native grasses following fire can inhibit establishment and growth of woody species. This may allow certain native herbaceous species to colonize and persist beneath gaps in the canopy. A field manipulative experiment with control, litter, and bare ground treatments was used to examine the impact of non-native grasses on growth and establishment of a native herbaceous species, Cryptantha muricata. C. muricata seedling survival, growth, and reproduction were greatest in the control treatment where non-native grasses were present. C. muricata plants growing in the presence of non-native grasses produced more than twice the number of flowers and more than twice the reproductive biomass of plants growing in the treatments where non-native grasses were removed. Total biomass and number of fruits were also greater in the plants growing in the presence of non-native grasses. Total biomass and reproductive biomass was also greater in late germinants than early germinants growing in the presence of non-native grasses. This study suggests a potential positive effect of non-native grasses on the performance of a particular native annual in a southern <span class="hlt">California</span> <span class="hlt">ecosystem</span>. PMID:25379790</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005DSRII..52..145T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005DSRII..52..145T"><span id="translatedtitle">Cetacean distributions relative to ocean processes in the northern <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tynan, Cynthia T.; Ainley, David G.; Barth, John A.; Cowles, Timothy J.; Pierce, Stephen D.; Spear, Larry B.</p> <p>2005-01-01</p> <p>Associations between cetacean distributions, oceanographic features, and bioacoustic backscatter were examined during two process cruises in the northern <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS) during late spring and summer 2000. Line-transect surveys of cetaceans were conducted across the shelf and slope, out to 150 km offshore from Newport, Oregon (44.6°N) to Crescent City, <span class="hlt">California</span> (41.9°N), in conjunction with multidisciplinary mesoscale and fine-scale surveys of ocean and <span class="hlt">ecosystem</span> structure. Occurrence patterns (presence/absence) of cetaceans were compared with hydrographic and ecological variables (e.g., sea surface salinity, sea surface temperature, thermocline depth, halocline depth, chlorophyll maximum, distance to the center of the equatorward jet, distance to the shoreward edge of the upwelling front, and acoustic backscatter at 38, 120, 200 and 420 kHz) derived from a towed, undulating array and a bioacoustic system. Using a multiple logistic regression model, 60.2% and 94.4% of the variation in occurrence patterns of humpback whales Megaptera novaeangliae during late spring and summer, respectively, were explained. Sea surface temperature, depth, and distance to the alongshore upwelling front were the most important environmental variables during June, when humpbacks occurred over the slope (200-2000 m). During August, when humpbacks concentrated over a submarine bank (Heceta Bank) and off Cape Blanco, sea surface salinity was the most important variable, followed by latitude and depth. Humpbacks did not occur in the lowest salinity water of the Columbia River plume. For harbor porpoise Phocoena phocoena, the model explained 79.2% and 70.1% of the variation in their occurrence patterns during June and August, respectively. During spring, latitude, sea surface salinity, and thermocline gradient were the most important predictors. During summer, latitude and distance to the inshore edge of the upwelling front were the most important variables. Typically a coastal species, harbor porpoises extended their distribution farther offshore at Heceta Bank and at Cape Blanco, where they were associated with the higher chlorophyll concentrations in these regions. Pacific white-sided dolphin Lagenorhynchus obliquidens was the most numerous small cetacean in early June, but was rare during August. The model explained 44.5% of the variation in their occurrence pattern, which was best described by distance to the upwelling front and acoustic backscatter at 38 kHz. The model of the occurrence pattern of Dall's porpoise Phocoenoides dalli was more successful when mesoscale variability in the CCS was higher during summer. Thus, the responses of cetaceans to biophysical features and upwelling processes in the northern CCS were both seasonally and spatially specific. Heceta Bank and associated flow-topography interactions were very important to a cascade of trophic dynamics that ultimately influenced the distribution of foraging cetaceans. The higher productivity associated with upwelling near Cape Blanco also had a strong influence on the distribution of cetaceans.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMOS53D..05D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMOS53D..05D"><span id="translatedtitle">Prototyping global Earth System Models at high resolution: Representation of climate, <span class="hlt">ecosystems</span>, and acidification in Eastern Boundary <span class="hlt">Currents</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dunne, J. P.; John, J. G.; Stock, C. A.</p> <p>2013-12-01</p> <p>The world's major Eastern Boundary <span class="hlt">Currents</span> (EBC) such as the <span class="hlt">California</span> <span class="hlt">Current</span> Large Marine <span class="hlt">Ecosystem</span> (CCLME) are critically important areas for global fisheries. Computational limitations have divided past EBC modeling into two types: high resolution regional approaches that resolve the strong meso-scale structures involved, and coarse global approaches that represent the large scale context for EBCs, but only crudely resolve only the largest scales of their manifestation. These latter global studies have illustrated the complex mechanisms involved in the climate change and acidification response in these regions, with the CCLME response dominated not by local adjustments but large scale reorganization of ocean circulation through remote forcing of water-mass supply pathways. While qualitatively illustrating the limitations of regional high resolution studies in long term projection, these studies lack the ability to robustly quantify change because of the inability of these models to represent the baseline meso-scale structures of EBCs. In the present work, we compare <span class="hlt">current</span> generation coarse resolution (one degree) and a prototype next generation high resolution (1/10 degree) Earth System Models (ESMs) from NOAA's Geophysical Fluid Dynamics Laboratory in representing the four major EBCs. We review the long-known temperature biases that the coarse models suffer in being unable to represent the timing and intensity of upwelling-favorable winds, along with lack of representation of the observed high chlorophyll and biological productivity resulting from this upwelling. In promising contrast, we show that the high resolution prototype is capable of representing not only the overall meso-scale structure in physical and biogeochemical fields, but also the appropriate offshore extent of temperature anomalies and other EBC characteristics. Results for chlorophyll were mixed; while high resolution chlorophyll in EBCs were strongly enhanced over the coarse resolution ESM, they were still considerably lower than observed values. In terms of representation of large scale circulation and biogeochemistry, results were also mixed, with the high resolution prototype addressing some, but not all, of the biases in the coarse resolution ESM. While considerable work remains to understand the <span class="hlt">current</span> strengths and weaknesses of the high resolution ESM and continue to improve fidelity, this work is a major step forward in demonstrating the added value of high resolution in global ESMs and represents a fundamental leap forward towards both ecological forecasting and long term projection of climate, <span class="hlt">ecosystem</span>, and acidification baselines and sensitivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3897708','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3897708"><span id="translatedtitle">Land Use Compounds Habitat Losses under Projected Climate Change in a Threatened <span class="hlt">California</span> <span class="hlt">Ecosystem</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Riordan, Erin Coulter; Rundel, Philip W.</p> <p>2014-01-01</p> <p>Given the rapidly growing human population in mediterranean-climate systems, land use may pose a more immediate threat to biodiversity than climate change this century, yet few studies address the relative future impacts of both drivers. We assess spatial and temporal patterns of projected 21st century land use and climate change on <span class="hlt">California</span> sage scrub (CSS), a plant association of considerable diversity and threatened status in the mediterranean-climate <span class="hlt">California</span> Floristic Province. Using a species distribution modeling approach combined with spatially-explicit land use projections, we model habitat loss for 20 dominant shrub species under unlimited and no dispersal scenarios at two time intervals (early and late century) in two ecoregions in <span class="hlt">California</span> (Central Coast and South Coast). Overall, projected climate change impacts were highly variable across CSS species and heavily dependent on dispersal assumptions. Projected anthropogenic land use drove greater relative habitat losses compared to projected climate change in many species. This pattern was only significant under assumptions of unlimited dispersal, however, where considerable climate-driven habitat gains offset some concurrent climate-driven habitat losses. Additionally, some of the habitat gained with projected climate change overlapped with projected land use. Most species showed potential northern habitat expansion and southern habitat contraction due to projected climate change, resulting in sharply contrasting patterns of impact between Central and South Coast Ecoregions. In the Central Coast, dispersal could play an important role moderating losses from both climate change and land use. In contrast, high geographic overlap in habitat losses driven by projected climate change and projected land use in the South Coast underscores the potential for compounding negative impacts of both drivers. Limiting habitat conversion may be a broadly beneficial strategy under climate change. We emphasize the importance of addressing both drivers in conservation and resource management planning. PMID:24466116</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24466116','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24466116"><span id="translatedtitle">Land use compounds habitat losses under projected climate change in a threatened <span class="hlt">California</span> <span class="hlt">ecosystem</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Riordan, Erin Coulter; Rundel, Philip W</p> <p>2014-01-01</p> <p>Given the rapidly growing human population in mediterranean-climate systems, land use may pose a more immediate threat to biodiversity than climate change this century, yet few studies address the relative future impacts of both drivers. We assess spatial and temporal patterns of projected 21(st) century land use and climate change on <span class="hlt">California</span> sage scrub (CSS), a plant association of considerable diversity and threatened status in the mediterranean-climate <span class="hlt">California</span> Floristic Province. Using a species distribution modeling approach combined with spatially-explicit land use projections, we model habitat loss for 20 dominant shrub species under unlimited and no dispersal scenarios at two time intervals (early and late century) in two ecoregions in <span class="hlt">California</span> (Central Coast and South Coast). Overall, projected climate change impacts were highly variable across CSS species and heavily dependent on dispersal assumptions. Projected anthropogenic land use drove greater relative habitat losses compared to projected climate change in many species. This pattern was only significant under assumptions of unlimited dispersal, however, where considerable climate-driven habitat gains offset some concurrent climate-driven habitat losses. Additionally, some of the habitat gained with projected climate change overlapped with projected land use. Most species showed potential northern habitat expansion and southern habitat contraction due to projected climate change, resulting in sharply contrasting patterns of impact between Central and South Coast Ecoregions. In the Central Coast, dispersal could play an important role moderating losses from both climate change and land use. In contrast, high geographic overlap in habitat losses driven by projected climate change and projected land use in the South Coast underscores the potential for compounding negative impacts of both drivers. Limiting habitat conversion may be a broadly beneficial strategy under climate change. We emphasize the importance of addressing both drivers in conservation and resource management planning. PMID:24466116</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23064248','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23064248"><span id="translatedtitle">The impact of antecedent fire area on burned area in southern <span class="hlt">California</span> coastal <span class="hlt">ecosystems</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Price, Owen F; Bradstock, Ross A; Keeley, Jon E; Syphard, Alexandra D</p> <p>2012-12-30</p> <p>Frequent wildfire disasters in southern <span class="hlt">California</span> highlight the need for risk reduction strategies for the region, of which fuel reduction via prescribed burning is one option. However, there is no consensus about the effectiveness of prescribed fire in reducing the area of wildfire. Here, we use 29 years of historical fire mapping to quantify the relationship between annual wildfire area and antecedent fire area in predominantly shrub and grassland fuels in seven southern <span class="hlt">California</span> counties, controlling for annual variation in weather patterns. This method has been used elsewhere to measure leverage: the reduction in wildfire area resulting from one unit of prescribed fire treatment. We found little evidence for a leverage effect (leverage = zero). Specifically our results showed no evidence that wildfire area was negatively influenced by previous fires, and only weak relationships with weather variables rainfall and Santa Ana wind occurrences, which were variables included to control for inter-annual variation. We conclude that this is because only 2% of the vegetation burns each year and so wildfires rarely encounter burned patches and chaparral shrublands can carry a fire within 1 or 2 years after previous fire. Prescribed burning is unlikely to have much influence on fire regimes in this area, though targeted treatment at the urban interface may be effective at providing defensible space for protecting assets. These results fit an emerging global model of fire leverage which position <span class="hlt">California</span> at the bottom end of a continuum, with tropical savannas at the top (leverage = 1: direct replacement of wildfire by prescribed fire) and Australian eucalypt forests in the middle (leverage ~ 0.25). PMID:23064248</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900055333&hterms=pigment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpigment','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900055333&hterms=pigment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpigment"><span id="translatedtitle">Seasonal and nonseasonal variability of satellite-derived surface pigment concentration in the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Strub, P. Ted; James, Corinne; Thomas, Andrew C.; Abbott, Mark R.</p> <p>1990-01-01</p> <p>The large-scale patterns of satellite-derived surface pigment concentration off the west coast of North America are presented and are averaged into monthly mean surface wind fields over the <span class="hlt">California</span> <span class="hlt">Current</span> system (CCS) for the July 1979 to June 1986 period. The patterns are discussed in terms of both seasonal and nonseasonal variability for the indicated time period. The large-scale seasonal characteristics of the <span class="hlt">California</span> <span class="hlt">Current</span> are summarized. The data and methods used are described, and the problems known to affect the satellite-derived pigment concentrations and the wind data used in the study are discussed. The statistical analysis results are then presented and discussed in light of past observations and theory. Details of the CZCS data processing are described, and details of the principal estimator pattern methodology used here are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.B43D0464A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.B43D0464A"><span id="translatedtitle">Carbon Sequestration and Nitrous Oxide Emissions from Urban Turfgrass <span class="hlt">Ecosystems</span> in Southern <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ampleman, M. D.; Czimczik, C. I.; Townsend-Small, A.; Trumbore, S. E.</p> <p>2008-12-01</p> <p>Irrigated turfgrass <span class="hlt">ecosystems</span> sequester carbon in soil organic matter, but they may also release nitrous oxide, due to fertilization associated with intensive management practices. Nitrous oxide is an important green house gas with a global warming potential (GWP) of 300 times that of carbon dioxide on a 100 yr time horizon. Although regular irrigation and fertilization of turfgrass create favorable conditions for both C storage and N2O release via nitrification and denitrification by soil microbes, emissions from these highly managed <span class="hlt">ecosystems</span> are poorly constrained. We quantified N2O emissions and C storage rates for turf grass in four urban parks in the city of Irvine, CA. The turf grass systems we studied were managed by the City of Irvine. Parks were established between 1975 and 2006 on former range land with the same initial parent material; are exposed to the same climate; and form a time series (chronosequence) for investigating rates of C accumulation. We also investigated the effects of management (e.g. grass species, fertilization rate), soil moisture and temperature, and park age on N2O emission from these parks. We quantified N2O emissions using static soil chamber with four 7 min. sampling intervals, and analyzed the samples using an electron capture gas chromatograph. Soil carbon accumulation rates were determined from the slope of the organic C inventory (from 0-20 cm depth) plotted against park age. C storage rates for soils in "leisure" areas were close to 2 Mg C ha-1 yr-1, similar to rates associated with forest regrowth in northeastern US forests. However, as park age and C storage increased, N2O emissions increased as well, such that emissions from the older parks (~20 ngN m-2 s-1) were comparable to published temperate agricultural fluxes. Initial estimates suggest that the GWP associated with N2O emissions approximately offsets the effect of C storage in these <span class="hlt">ecosystems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=api&pg=2&id=EJ1038648','ERIC'); return false;" href="http://eric.ed.gov/?q=api&pg=2&id=EJ1038648"><span id="translatedtitle">A Comparison between Value-Added School Estimates and <span class="hlt">Currently</span> Used Metrics of School Accountability in <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Fagioli, Loris P.</p> <p>2014-01-01</p> <p>This study compared a value-added approach to school accountability to the <span class="hlt">currently</span> used metrics of accountability in <span class="hlt">California</span> of Adequate Yearly Progress (AYP) and Academic Performance Index (API). Five-year student panel data (N?=?53,733) from 29 elementary schools in a large <span class="hlt">California</span> school district were used to address the research…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=added&pg=5&id=EJ1038648','ERIC'); return false;" href="http://eric.ed.gov/?q=added&pg=5&id=EJ1038648"><span id="translatedtitle">A Comparison between Value-Added School Estimates and <span class="hlt">Currently</span> Used Metrics of School Accountability in <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Fagioli, Loris P.</p> <p>2014-01-01</p> <p>This study compared a value-added approach to school accountability to the <span class="hlt">currently</span> used metrics of accountability in <span class="hlt">California</span> of Adequate Yearly Progress (AYP) and Academic Performance Index (API). Five-year student panel data (N?=?53,733) from 29 elementary schools in a large <span class="hlt">California</span> school district were used to address the research</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5714557','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5714557"><span id="translatedtitle">Deposition and processing of airborne nitrogen pollutants in Mediterranean-type <span class="hlt">ecosystems</span> of southern <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Riggan P.J.; Lockwood, R.N.; Lopez, E.N.</p> <p>1985-09-01</p> <p>Atmospheric nitrogen deposition, associated with chronic urban air pollution, has produced stream water nitrate concentrations as high as 7.0 mg of N L/sup -1/ in chaparral watershed in the San Gabriel Mountains of Los Angeles County, CA. Stream water (NO/sub 3//sup -/) and discharge were greatest at high flow and may contribute significantly to existing groundwater NO/sub 3//sup -/ pollution. Annual NO/sub 3//sup -/ discharge ranged from 0.04 to 10.0 kg of N ha/sup -1/ over 4 years. Canopy throughfall and precipitation inputs of 23.3 and 8.2 kg of N ha/sup -1/ year/sup -1/ were high relative to other undisturbed <span class="hlt">ecosystems</span> nationwide. Dry deposition was apparently a major source of the throughfall nitrogen. NO/sub 3//sup -/ concentrations from nearby, relatively unpolluted watersheds were lower by 1-3 orders of magnitude. NO/sub 3//sup -/ yield was elevated on watersheds where chaparral was converted to grassland in 1960 and may be greatly accelerated after wildfire because of high postfire NH/sub 4//sup +/ concentrations and rapid nitrification in terrestrial and aquatic <span class="hlt">ecosystems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/107133','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/107133"><span id="translatedtitle">The impact of El Nino on island <span class="hlt">ecosystems</span> in the gulf of <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Polis, G.A.; Hurd, S.D.</p> <p>1995-09-01</p> <p>The El Nino event of 1992-1993 had significant effects on all functional levels of the terrestrial food web of islands in the Gulf of <span class="hlt">California</span>. These islands are normally very dry; however, during this El Nino event, annual precipitation was nearly five times the median annual precipitation. This caused tremendous increases in plant cover and a significant rise in aerial arthropod abundance. At first, spiders benefited from increased productivity: in 1992, spiders increased to their highest densities in the three years of the study. However, in 1993, despite continued high plant cover and insect prey abundance, spider densities dropped precipitously. This decrease appears to be due to the emergence of numerous parasitoid wasps that formed a hidden trophic influence. Wasps were ineffective at controlling spider densities during dry years due to the absence of their adult food, nectar and pollen from flowering land plants. Abundant flowers during El Nino allowed the wasp population to increase and reproduce successfully.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H51A1192K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H51A1192K"><span id="translatedtitle">Root distribution in a <span class="hlt">California</span> semi-arid oak savanna <span class="hlt">ecosystem</span> as determined by conventional sampling and ground penetrating radar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koteen, L. E.; Raz-Yaseef, N.; Baldocchi, D. D.</p> <p>2011-12-01</p> <p>Koteen, Laura E., Raz-Yaseef, Naama, and Dennis D. Baldocchi University of <span class="hlt">California</span>, Berkeley <span class="hlt">California</span>'s blue oak, Quercus douglasii, is a unique tree in several ways. Despite the intense heat of <span class="hlt">California</span>'s central valley and Sierra foothills, and absence of precipitation during dry summer months, blue oaks are winter deciduous, and rely on a suite of drought adaptation measures for highly-efficient water use. To date, much more is known about aboveground dynamics in semi-arid oak savanna <span class="hlt">ecosystems</span> than belowground. Yet, the root system is instrumental in ensuring oak survival and in determining the magnitude and timing of land-atmospheric fluxes via its control of water and nutrient supply to aboveground processes and soil moisture content. Tree root distribution is notoriously heterogeneous. Therefore a comprehensive sampling effort is needed in order to optimally represent it. To further understand the patterns of water use in oak savanna <span class="hlt">ecosystems</span> in the Sierra foothills of <span class="hlt">California</span>, we have sought to characterize the root system by depth. To accomplish this goal, we have sampled the root system using conventional sampling methods (i.e. pit and core sampling), in conjunction with ground penetrating radar (GPR). Using both methods together made it possible to compensate for the limitations of each: Fine roots can only be detected by conventional sampling, and involve time intensive work in the lab, limiting sample size. GPR, on the other hand, allows for much greater spatial coverage and therefore more comprehensive characterization of the coarse root component. An extensive field campaign was executed during May 2011. 7 tree areas where chosen, representing the range of tree sizes and composition at the research site: 2 small trees, 2 large trees and 2 tree clusters. One additional very large tree that has undergone extensive additional physiological measurements was also chosen in order to posit and test hypotheses about linkages among root, soil water and photosynthetic processes. We extracted root cores according to a radial sampling scheme, with a 5 cm diameter soil auger at distances of 0.5, 1 and 1.5 the mean canopy radius from the tree. Soil cores were removed in intervals from 0-10, 10-20, 20-40, 40-60, and 60 cm to bedrock, which varied in depth from 20 cm to 1 meter. Fine roots were rinsed of soil, separated from debris, dried and weighed. GPR measurements were conducted using Noggin1000 (Sensors and Software Inc.). Prior to measurements, 8 by 8 m grids were prepared, with line density of 20 cm. Following GPR measurements, 2 pits of size 60 by 100 cm were dug down to the bedrock. Coarse roots were removed in regular depth intervals, sieved and taken to the lab. In the lab, coarse roots were washed of soil, dried, sorted into size classes and weighed. GPR visual data was analyzed using appropriate software, and the number of pixels identified as roots was linked to root biomass from pits. Lastly, 3D imaging of the root structure was achieved through the use of visualization software. The knowledge we have gained through this research will be used to improve our understanding of tree water usage, and soil moisture dynamics in this semi-arid oak savanna system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMGC13B1082G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMGC13B1082G"><span id="translatedtitle">Modeling the yield potential of dryland canola under <span class="hlt">current</span> and future climates in <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>George, N.; Kaffka, S.; Beeck, C.; Bucaram, S.; Zhang, J.</p> <p>2012-12-01</p> <p>Models predict that the climate of <span class="hlt">California</span> will become hotter, drier and more variable under future climate change scenarios. This will lead to both increased irrigation demand and reduced irrigation water availability. In addition, it is predicted that most common Californian crops will suffer a concomitant decline in productivity. To remain productive and economically viable, future agricultural systems will need to have greater water use efficiency, tolerance of high temperatures, and tolerance of more erratic temperature and rainfall patterns. Canola (Brassica napus) is the third most important oilseed globally, supporting large and well-established agricultural industries in Canada, Europe and Australia. It is an agronomically useful and economically valuable crop, with multiple end markets, that can be grown in <span class="hlt">California</span> as a dryland winter rotation with little to no irrigation demand. This gives canola great potential as a new crop for Californian farmers both now and as the climate changes. Given practical and financial limitations it is not always possible to immediately or widely evaluate a crop in a new region. Crop production models are therefore valuable tools for assessing the potential of new crops, better targeting further field research, and refining research questions. APSIM is a modular modeling framework developed by the Agricultural Production Systems Research Unit in Australia, it combines biophysical and management modules to simulate cropping systems. This study was undertaken to examine the yield potential of Australian canola varieties having different water requirements and maturity classes in <span class="hlt">California</span> using APSIM. The objective of the work was to identify the agricultural regions of <span class="hlt">California</span> most ideally suited to the production of Australian cultivars of canola and to simulate the production of canola in these regions to estimate yield-potential. This will establish whether the introduction and in-field evaluation of better-adapted canola varieties can be justified, and the potential value of a <span class="hlt">California</span> canola industry both now and in the future. Winter annual crops like canola use rainfall in a Mediterranean climate like <span class="hlt">California</span> more efficiently than spring or summer crops. Our results suggest that under <span class="hlt">current</span> production costs and seed prices, dry farmed canola will have good potential in certain areas of the <span class="hlt">California</span>. Canola yields decline with annual winter precipitation, however economically viable yields are still achieved at relatively precipitation levels (200 mm). Results from simulation, combined with related economic modeling (reported elsewhere) suggest that canola will be viable in a variety of production systems in the northern Sacramento Valley and some coastal locations, even under drier future climate scenarios. The in-field evaluation of Australian canola varieties should contribute to maintain or improving resource use efficiency and farm profitability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMPP41C1538F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMPP41C1538F"><span id="translatedtitle">Holocene climate variability in the NE Pacific: Insight from connections between the Gulf of Alaska and the <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Finney, B. P.; Addison, J. A.</p> <p>2009-12-01</p> <p>Historically, decadal-scale climatic change in the North Pacific region appears to be characterized by circulation modes with coherent and recognizable spatial patterns (i.e., PDO). Examination of trends in paleo-records from widespread regions, allow recognition of how these modes have varied over time. Changes in patterns of correlations of proxies between regions suggest several periods of reorganization of ocean-atmospheric circulation during the Holocene. Major shifts appear to have occurred during climatic transitions into the Neoglacial period (ca 4000 BP), and into and out of the Little Ice Age (LIA; ca. AD 1200 and 1850). Recent paleoclimatic studies from Mt, Logan ice cores and elsewhere suggest these transitions reflect shifts between atmospheric circulation modes of more zonal vs. more meridional flow. These shifts in climate can be tracked into variability in primary productivity and higher trophic levels, such as pelagic fish, in the North Pacific marine <span class="hlt">ecosystem</span>. Within the Gulf of Alaska, new high-resolution reconstructions of ocean paleoproductivity based on multiproxy analysis of sediment cores suggest persistent variability over multidecadal scales, punctuated by abrupt state changes in overall productivity level. Such mega-regime shifts are of a different nature and larger amplitude than historical regime-shifts. Records of Alaskan salmon are generally positively correlated with Gulf of Alaska productivity. Interestingly, records of <span class="hlt">California</span> <span class="hlt">Current</span> sardine and anchovy abundance reveal different relationships to Alaska salmon abundance during the LIA relative to historical observations. It is likely that a different pattern of ocean-atmospheric circulation during the LIA, resulted in different relationships between these regional <span class="hlt">ecosystems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42..419T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42..419T"><span id="translatedtitle">Particulate ?15N in laminated marine sediments as a proxy for mixing between the <span class="hlt">California</span> Undercurrent and the <span class="hlt">California</span> <span class="hlt">Current</span>: A proof of concept</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tems, Caitlin E.; Berelson, William M.; Prokopenko, Maria G.</p> <p>2015-01-01</p> <p>measurements of particulate ?15N in coastal marine laminated sediments provide a high-resolution proxy for fluctuations in the intensity of denitrification in the water column. In the eastern tropical North Pacific oxygen minimum zone, this denitrification signal is transported northward by the <span class="hlt">California</span> Undercurrent, thus serving as a tracer of ocean circulation. This is verified through comparisons between salinity in the thermocline off Southern <span class="hlt">California</span> (Santa Monica Basin) and the difference between ?15Nsed within age equivalent sediments from a southern (Pescadero Slope) and northern (Santa Monica Basin) site. Trends in this parameter, ??15Nsed, relate to Pacific Decadal Oscillation (PDO) phase changes between 1900 and 1990. We hypothesize that the decline in ??15Nsed during warm PDO phases is due to a strengthening of the <span class="hlt">California</span> Undercurrent transporting 15N-enriched nitrate from the eastern tropical North Pacific northward. The deviation from this trend after 1990 suggests recent changes in circulation and/or <span class="hlt">California</span> <span class="hlt">Current</span> water nutrient biogeochemistry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGC23B0931R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGC23B0931R"><span id="translatedtitle">Quantification of Lateral Carbon Flux in a Chaparral <span class="hlt">Ecosystem</span> in Southern <span class="hlt">California</span> Alessandra Rossi, Walter Oechel, Patrick Murphy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rossi, A.; Oechel, W. C.; Murphy, P.</p> <p>2013-12-01</p> <p>The lateral transport of carbon is a horizontal transfer of carbon away from the area it was withdrawn from the atmosphere (Ciais et al. 2006). Research regarding horizontal C transport has received much less attention in arid and semi-arid regions compared to other types of <span class="hlt">ecosystems</span>. Drylands represent around 47.2% (Lal 2004) of the global terrestrial area and despite characterized by relatively low carbon flux, drylands comprise approximately 15.5% of the world's total soil organic carbon (SOC) (Eswaran et al. 2000, Schlesinger, 1991). Moreover, these dry areas contain at least as much soil inorganic carbon (SIC) as SOC (Eswaran et al. 2000). Therefore, these areas potentially have a large contribution to the global carbon budget and they deserve attention. A long-term observation of CO2 flux with the eddy covariance technique has been conducted since 1997 at Sky Oaks Field Station in Southern <span class="hlt">California</span>, an area of Mediterranean climate at the climatic transition between semiarid area and desert. The long term record of CO2 flux showed the area has been a sink of CO2 of over -0.2 kgCm-2yr-1. In addition to evaluating vertical carbon fluxes, we initiated a project to evaluate lateral carbon transports using litter traps, sediment fences and two small weirs adjacent to the eddy covariance site. Preliminary results indicate that the lateral transfer of C in the area may offset the vertical influx to this shrub <span class="hlt">ecosystem</span>. However, it is still necessary to develop the methodology to compare vertical carbon flux and the lateral carbon fluxes more accurately.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19475924','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19475924"><span id="translatedtitle">Spatiotemporal trends in fish mercury from a mine-dominated <span class="hlt">ecosystem</span>: Clear Lake, <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Suchanek, Thomas H; Eagles-Smith, Collin A; Slotton, Darell G; Harner, E James; Colwell, Arthur E; Anderson, Norman L; Mullen, Lauri H; Flanders, John R; Adam, David P; McElroy, Kenneth J</p> <p>2008-12-01</p> <p>Clear Lake, <span class="hlt">California</span>, USA, receives acid mine drainage and mercury (Hg) from the Sulphur Bank Mercury Mine, a U.S. Environmental Protection Agency (U.S. EPA) Superfund Site that was active intermittently from 1873 to 1957 and partially remediated in 1992. Mercury concentrations were analyzed primarily in four species of Clear Lake fishes: inland silversides (Menidia beryllina, planktivore), common carp (Cyprinus carpio, benthic scavenger/omnivore), channel catfish (Ictalurus punctatus, benthic omnivorous predator), and largemouth bass (Micropterus salmoides, piscivorous top predator). These data represent one of the largest fish Hg data sets for a single site, especially in <span class="hlt">California</span>. Spatially, total Hg (TotHg) in silversides and bass declined with distance from the mine, indicating that the mine site represents a point source for Hg loading to Clear Lake. Temporally, fish Hg has not declined significantly over 12 years since mine site remediation. Mercury concentrations were variable throughout the study period, with no monotonic trends of increase or decrease, except those correlated with boom and bust cycles of an introduced fish, threadfin shad (Dorosoma petenense). However, stochastic events such as storms also influence juvenile largemouth bass Hg as evidenced during an acid mine drainage overflow event in 1995. Compared to other sites regionally and nationally, most fish in Clear Lake exhibit Hg concentrations similar to other Hg-contaminated sites, up to approximately 2.0 mg/kg wet mass (WM) TotHg in largemouth bass. However, even these elevated concentrations are less than would be anticipated from such high inorganic Hg loading to the lake. Mercury in some Clear Lake largemouth bass exceeded all human health fish consumption guidelines established over the past 25 years by the U.S. Food and Drug Administration (1.0 mg/kg WM), the National Academy of Sciences (0.5 mg/kg WM), and the U.S. EPA (0.3 mg/kg WM). Mercury in higher trophic level fishes exceeds ecotoxicological risk assessment estimates for concentrations that would be safe for wildlife, specifically the nonlisted Common Merganser and the recently delisted Bald Eagle. Fish populations of 11 out of 18 species surveyed exhibited a significant decrease in abundance with increasing proximity to the mine; this decrease is correlated with increasing water and sediment Hg. These trends may be related to Hg or other lake-wide gradients such as distribution of submerged aquatic vegetation. PMID:19475924</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7015985','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7015985"><span id="translatedtitle">Interannual variation in climate-potential net primary productivity relationships in differing <span class="hlt">ecosystems</span> of <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Koch, G.W.; Randerson, J.T. )</p> <p>1994-06-01</p> <p>The seasonality and interannual variation in potential net primary production (NPP) were examined in differing vegetation types in <span class="hlt">California</span> over three years of contrasting precipitation using co-registered maps of climate, vegetation, and 1km biweekly NDVI derived from high resolution satellite AVHRR data. Differences in seasonality of the vegetation types (annual grassland, chamise chaparral, deciduous oak woodland, and evergreen oak) were clearly evident and corresponded well to patterns observed in field studies. In years and locations having high precipitation the annual peak in NDVI occurred later in all vegetation classes. The annual sum of biweekly NDVI was correlated with annual precipitation in all vegetation types, although the slopes and intercepts of the regressions differed among types. Annual grassland showed the largest increase in sumNDVI per unit increase in total precipitation and most of the variation in grassland sumNDVI was explained by variation in autumn precipitation. In general the ratio of sumNDVI to annual precipitation was dependent on the temporal distribution of precipitation with respect to the long-term average pattern. Published relationships between precipitation and NPP were used to develop equations relating annual NDVI sum to NPP.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70104148','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70104148"><span id="translatedtitle">Environmental fate of fungicides and other <span class="hlt">current</span>-use pesticides in a central <span class="hlt">California</span> estuary</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Smalling, Kelly L.; Kuivila, Kathryn M.; Orlando, James L.; Phillips, Bryn M.; Anderson, Brian S.; Siegler, Katie; Hunt, John W.; Hamilton, Mary</p> <p>2013-01-01</p> <p>The <span class="hlt">current</span> study documents the fate of <span class="hlt">current</span>-use pesticides in an agriculturally-dominated central <span class="hlt">California</span> coastal estuary by focusing on the occurrence in water, sediment and tissue of resident aquatic organisms. Three fungicides (azoxystrobin, boscalid, and pyraclostrobin), one herbicide (propyzamide) and two organophosphate insecticides (chlorpyrifos and diazinon) were detected frequently. Dissolved pesticide concentrations in the estuary corresponded to the timing of application while bed sediment pesticide concentrations correlated with the distance from potential sources. Fungicides and insecticides were detected frequently in fish and invertebrates collected near the mouth of the estuary and the contaminant profiles differed from the sediment and water collected. This is the first study to document the occurrence of many <span class="hlt">current</span>-use pesticides, including fungicides, in tissue. Limited information is available on the uptake, accumulation and effects of <span class="hlt">current</span>-use pesticides on non-target organisms. Additional data are needed to understand the impacts of pesticides, especially in small agriculturally-dominated estuaries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41.7611S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41.7611S"><span id="translatedtitle">Swept away by a turbidity <span class="hlt">current</span> in Mendocino submarine canyon, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sumner, E. J.; Paull, C. K.</p> <p>2014-11-01</p> <p>We present unique observations and measurements of a dilute turbidity <span class="hlt">current</span> made with a remotely operated vehicle in 400 m water depth near the head of Mendocino Canyon, <span class="hlt">California</span>. The flow had a two-layer structure with a thin (0.5 to 30 m), relatively dense (<0.04 vol %) and fast (up to ~1.7 m/s) wedge-shaped lower layer overlain by a thicker (up to 89 m) more dilute and slower <span class="hlt">current</span>. The fast moving lower layer lagged the slow moving, dilute flow front by 14 min, which we infer resulted from the interaction of two initial pulses. The two layers were strongly coupled, and the sharp interface between the layers was characterized by a wave-like instability. This is the first field-scale data from a turbidity <span class="hlt">current</span> to show (i) the complex dynamics of the head of a turbidity <span class="hlt">current</span> and (ii) the presence of multiple layers within the same event.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3953659','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3953659"><span id="translatedtitle">Effects of Sewage Discharge on Trophic State and Water Quality in a Coastal <span class="hlt">Ecosystem</span> of the Gulf of <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vargas-Gonzlez, Hctor Hugo; Arreola-Lizrraga, Jos Alfredo; Mendoza-Salgado, Renato Arturo; Mndez-Rodrguez, La Celina; Lechuga-Deveze, Carlos Hernando; Padilla-Arredondo, Gustavo; Cordoba-Matson, Miguel</p> <p>2014-01-01</p> <p>This paper provides evidence of the effects of urban wastewater discharges on the trophic state and environmental quality of a coastal water body in a semiarid subtropical region in the Gulf of <span class="hlt">California</span>. The concentrations of dissolved inorganic nutrients and organic matter from urban wastewater primary treatment were estimated. La Salada Cove was the receiving water body and parameters measured during an annual cycle were temperature, salinity, dissolved oxygen, nitrite, nitrate, ammonia, orthophosphate, and chlorophyll a. The effects of sewage inputs were determined by using Trophic State Index (TRIX) and the Arid Zone Coastal Water Quality Index (AZCI). It was observed that urban wastewater of the city of Guaymas provided 1,237?ton N yr?1 and 811?ton P yr?1 and TRIX indicated that the receiving water body showed symptoms of eutrophication from an oligotrophic state to a mesotrophic state; AZCI also indicated that the environmental quality of the water body was poor. The effects of urban wastewater supply with insufficient treatment resulted in symptoms of eutrophication and loss of ecological functions and services of the coastal <span class="hlt">ecosystem</span> in La Salada Cove. PMID:24711731</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24711731','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24711731"><span id="translatedtitle">Effects of sewage discharge on trophic state and water quality in a coastal <span class="hlt">ecosystem</span> of the Gulf of <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vargas-Gonzlez, Hctor Hugo; Arreola-Lizrraga, Jos Alfredo; Mendoza-Salgado, Renato Arturo; Mndez-Rodrguez, La Celina; Lechuga-Deveze, Carlos Hernando; Padilla-Arredondo, Gustavo; Cordoba-Matson, Miguel</p> <p>2014-01-01</p> <p>This paper provides evidence of the effects of urban wastewater discharges on the trophic state and environmental quality of a coastal water body in a semiarid subtropical region in the Gulf of <span class="hlt">California</span>. The concentrations of dissolved inorganic nutrients and organic matter from urban wastewater primary treatment were estimated. La Salada Cove was the receiving water body and parameters measured during an annual cycle were temperature, salinity, dissolved oxygen, nitrite, nitrate, ammonia, orthophosphate, and chlorophyll a. The effects of sewage inputs were determined by using Trophic State Index (TRIX) and the Arid Zone Coastal Water Quality Index (AZCI). It was observed that urban wastewater of the city of Guaymas provided 1,237 ton N yr(-1) and 811 ton P yr(-1) and TRIX indicated that the receiving water body showed symptoms of eutrophication from an oligotrophic state to a mesotrophic state; AZCI also indicated that the environmental quality of the water body was poor. The effects of urban wastewater supply with insufficient treatment resulted in symptoms of eutrophication and loss of ecological functions and services of the coastal <span class="hlt">ecosystem</span> in La Salada Cove. PMID:24711731</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMPP41B1457G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMPP41B1457G"><span id="translatedtitle">An Extreme Expression of the <span class="hlt">California</span> <span class="hlt">Current</span> during the Holocene: New Evidence from the Washington Margin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Griffin, H.; Shevenell, A. E.; Hendy, I. L.; Emerson, S. R.</p> <p>2008-12-01</p> <p>A multi-proxy bulk sedimentary geochemical and foraminiferal faunal study of a sediment core (TTN131-4 GC36; 4630'N, 12530'W, 1951m) from the continental slope off Washington State reveals millennial-scale variability in ocean circulation over the past 8000 years and offers a novel marine perspective on regional Holocene climate variability. Foraminiferal isotopes, faunal census data, and bulk sedimentary Corg, CaCO3 and trace metal concentrations were determined for GC36. Planktonic foraminiferal faunal records suggest cooler than present SSTs between 7 and 4.5 ka. Between 4.5 and 3 ky, benthic foraminifer ?18O and ?13C records display shifts towards more positive values (0.39 and 0.9, respectively), Corg increases, and sedimentary Re and U suggest a shift from less well oxygenated sedimentary conditions at 4 ka to more oxygenated sediments by 3.5 ka, an interpretation supported by benthic foraminifer assemblages. The Washington margin paleoceanographic data generally compliments previous studies from more southerly margin sites that suggest insolation-driven strengthening of the North Pacific High, resulting in a stronger <span class="hlt">California</span> <span class="hlt">Current</span> and increased regional coastal upwelling. This is expressed off the Oregon Margin as stronger upwelling and cooler SSTs as gyral waters are forced off shore. A reduction in the southward flow of the <span class="hlt">California</span> <span class="hlt">Current</span> and decreased upwelling has been proposed between 4.8 and 3.6 ka. Prior to ~ 4 ka, foraminiferal data and bulk sedimentary data support a stronger <span class="hlt">California</span> <span class="hlt">Current</span> System and coastal upwelling. Corg, however, displays an opposing interpretation that may be related to a change in preservation history. After ~ 4 ka planktonic foraminiferal assemblages and benthic foraminiferal data display increased variability, likely related to the weakening of the North Pacific high pressure system and the development of modern oceanographic and atmospheric circulation regimes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900060071&hterms=pigment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpigment','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900060071&hterms=pigment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpigment"><span id="translatedtitle">Seasonal and interannual variability of pigment concentrations across a <span class="hlt">California</span> <span class="hlt">Current</span> frontal zone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomas, A. C.; Strub, P. T.</p> <p>1990-01-01</p> <p>The seasonal and interannual variability of the latitudinal position of the <span class="hlt">California</span> <span class="hlt">Current</span> frontal zone was investigated by examining satellite images of phytoplankton pigment from the coastal-zone color scanner for the periods 1979-1983 and 1986. The pigment concentrations associated with the zonal front were also determined. A general seasonal cycle of pigment concentrations is was established. It was found that variations in the frontal structure are controlled primarily by changes in pigment concentration north of the front. Seasonal variations were found to be minimal south of the front, where pigment concentrations remain low throughout the spring, summer, and fall.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.1241Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.1241Z"><span id="translatedtitle">The 2014-2015 warming anomaly in the Southern <span class="hlt">California</span> <span class="hlt">Current</span> System observed by underwater gliders</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zaba, Katherine D.; Rudnick, Daniel L.</p> <p>2016-02-01</p> <p>Large-scale patterns of positive temperature anomalies persisted throughout the surface waters of the North Pacific Ocean during 2014-2015. In the Southern <span class="hlt">California</span> <span class="hlt">Current</span> System, measurements by our sustained network of underwater gliders reveal the coastal effects of the recent warming. Regional upper ocean temperature anomalies were greatest since the initiation of the glider network in 2006. Additional observed physical anomalies included a depressed thermocline, high stratification, and freshening; induced biological consequences included changes in the vertical distribution of chlorophyll fluorescence. Contemporaneous surface heat flux and wind strength perturbations suggest that local anomalous atmospheric forcing caused the unusual oceanic conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850020217','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850020217"><span id="translatedtitle">Towards a study of synoptic-scale variability of the <span class="hlt">California</span> <span class="hlt">current</span> system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1985-01-01</p> <p>A West Coast satellite time series advisory group was established to consider the scientific rationale for the development of complete west coast time series of imagery of sea surface temperature (as derived by the Advanced Very High Resolution Radiometer on the NOAA polar orbiter, and near-surface phytoplankton pigment concentrations (as derived by the Coastal Zone Color Scanner on Nimbus 7). The scientific and data processing requirements for such time series are also considered. It is determined that such time series are essential if a number of scientific questions regarding the synoptic-scale dynamics of the <span class="hlt">California</span> <span class="hlt">Current</span> System are to be addressed. These questions concern both biological and physical processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.B23D1579P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.B23D1579P"><span id="translatedtitle">Climate Effects on Soil Carbon Sequestration in a Grass, Oak and Conifer <span class="hlt">Ecosystem</span> of <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pittiglio, S. L.; Zasoski, R.</p> <p>2007-12-01</p> <p>Dissolved organic matter (DOM) leaching from decomposing detritus accumulated above mineral soils is an important carbon (C) and nitrogen (N) flux that influences biogeochemical processes, C sequestration and the health of individual <span class="hlt">ecosystems</span>. Previous studies have shown that the main process controlling DOM mobility in soils is sorption in the mineral horizons that adds to stabilized organic matter pools. The objective of this study was to determine the effect of temperature and incubation time on DOC and DON biodegradation and sorption in the mineral soil. Surface litter from a grass, oak and a conifer site were leached with deionized water for 5, 15 or 96 hours at 4, 20 or 30oC. The resulting DOM solutions were characterized using 13C NMR, XAD-8 resin and UV-vis spectroscopy. The biodegradable fraction (BDOC) of these solutions was quantified using inoculum from A horizon soils. The DOM solutions were also used in sorption experiments on A horizon soils. Supernatant from the A horizon sorption experiment was then used in a sorption experiment on Bt horizon soils and analyzed for BDOC using Bt horizon inoculum. The ability of the soils to adsorb DOC increased with increasing aromaticity in the DOC solution. Therefore, conifer DOM exhibited greater sorption than oak and grass DOM due to higher aromaticity. In all horizons, we observed net release of indigenous OM when OM-free solution was added. Net release of OM was greatest from the soils from the pine site, which had the greatest OM content among the soils we studied. ***Results still pending***</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987CSR.....7....1B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987CSR.....7....1B"><span id="translatedtitle">Pattern and persistence of a nearshore planktonic <span class="hlt">ecosystem</span> off Southern <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barnett, Arthur M.; Jahn, Andrew E.</p> <p>1987-01-01</p> <p>Three related data sets from a baseline environmental survey on the continental shelf at San Onofre, <span class="hlt">California</span>, consisting of: (1) zooplankton pumped from discrete depths on transects between the 8- and 30-m contours, sampled from 1976 to 1980; (2) zooplankton from oblique net hauls on a transect from 8 to 100 m sampled at 2-week intervals for 1 y, 1978-1979; and (3) vertical profiles of temperature, nutrients and plant pigments corresponding closely in time and space to the oblique net hauls, are used to describe cross-shelf zooplankton abundance patterns, community composition, and seasonal and shorter-term variations in cross-shelf zonation and their relation to variations in physical and chemical measures. Of 15 taxa tested for multiyear average patterns, threethe copepods Acartia clausi and Oithona oculata, and barnacle larvaehad centers of abundance shoreward of the 30-m contour and near the bottom. No differences were detected in the cross-shelf pattern between San Onofre and a transect 12 km southeast. Throughout the year, nearshore and offshore assemblages were distinguishable, the change occurring at about the 30-m contour. The offshore one, represented by the copepods Calanus pacificus, Eucalanus californicus and Rhincalanus nasutus, occupied water having less chlorophyll and less near-surface nutrient, i.e. of more oceanic character. In spring and summer, most nearshore taxa shifted slightly seaward, leaving a third assemblage, characterized by a very high abundance of Acartia spp. copepodids and maximum abundances of A. clausi and O. oculata near the beach. Three upwelling episodes resulted in marked increases in chlorophyll and nutrients, but not in cross-shelf gradients of these properties, as were noted at most other times. Maximum disturbance of cross-shelf zooplankton zonation was observed during a wintertime intrusion of offshore surface water, but the zonation was never obliterated. Nearshore zooplankton patterns appear to be protected from dislocation by the shallow shelf and sustained by phytoplankton distributed in a manner peculiar to the nearshore zone. Typically, shallow nearshore waters were richer in chlorophyll and nutrients than offshore waters of the same depth. The cross-shelf chlorophyll and nutrient profiles, in turn, appear to result from increased eddy diffusion and nutrient recycling in shallow waters, perhaps augmented by longshore transport from quasi-permanent, local upwelling nodes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70012672','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70012672"><span id="translatedtitle">Harmonic analysis of tides and tidal <span class="hlt">currents</span> in South San Francisco Bay, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cheng, R.T.; Gartner, J.W.</p> <p>1985-01-01</p> <p>Water level observations from tide stations and <span class="hlt">current</span> observations from <span class="hlt">current</span>-meter moorings in South San Francisco Bay (South Bay), <span class="hlt">California</span> have been harmonically analysed. At each tide station, 13 harmonic constituents have been computed by a least-squares regression without inference. Tides in South Bay are typically mixed; there is a phase lag of approximately 1 h and an amplification of 1??5 from north to south for a mean semi-diurnal tide. Because most of the <span class="hlt">current</span>-meter records are between 14 and 29 days, only the five most important harmonics have been solved for east-west and north-south velocity components. The eccentricity of tidal-<span class="hlt">current</span> ellipse is generally very small, which indicates that the tidal <span class="hlt">current</span> in South Bay is strongly bidirectional. The analyses further show that the principal direction and the magnitude of tidal <span class="hlt">current</span> are well correlated with the basin bathymetry. Patterns of Eulerian residual circulation deduced from the <span class="hlt">current</span>-meter data show an anticlockwise gyre to the west and a clockwise gyre to the east of the main channel in the summer months due to the prevailing westerly wind. Opposite trends have been observed during winter when the wind was variable. ?? 1985.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4411113','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4411113"><span id="translatedtitle"><span class="hlt">Current</span> Status of Western Yellow-Billed Cuckoo along the Sacramento and Feather Rivers, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p>To evaluate the <span class="hlt">current</span> status of the western population of the Yellow-billed Cuckoo (Coccyzus americanus) along the Sacramento and Feather rivers in <span class="hlt">Californias</span> Sacramento Valley, we conducted extensive call playback surveys in 2012 and 2013. We also quantified the amount and distribution of potential habitat. Our survey transects were randomly located and spatially balanced to sample representative areas of the potential habitat. We estimated that the total area of potential habitat was 8,134 ha along the Sacramento River and 2,052 ha along the Feather River, for a total of 10,186 ha. Large-scale restoration efforts have created potential habitat along both of these rivers. Despite this increase in the amount of habitat, the number of cuckoos we detected was extremely low. There were 8 detection occasions in 2012 and 10 occasions in 2013 on the Sacramento River, in both restored and remnant habitat. We had no detections on the Feather River in either year. We compared our results to 10 historic studies from as far back as 1972 and found that the Yellow-billed Cuckoo had unprecedentedly low numbers in 2010, 2012, and 2013. The <span class="hlt">current</span> limiting factor for the Yellow-billed Cuckoo in the Sacramento Valley is likely not the amount of appropriate vegetation, as restoration has created more habitat over the last 30 years. Reasons for the cuckoo decline on the Sacramento and Feather rivers are unclear. PMID:25915801</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGC41D..04B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGC41D..04B"><span id="translatedtitle">Integrated climate/land use/hydrological change scenarios for assessing threats to <span class="hlt">ecosystem</span> services on <span class="hlt">California</span> rangelands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Byrd, K. B.; Flint, L. E.; Casey, C. F.; Alvarez, P.; Sleeter, B. M.; Sohl, T.</p> <p>2013-12-01</p> <p>In <span class="hlt">California</span> there are over 18 million acres of rangelands in the Central Valley and the interior Coast Range, most of which are privately owned and managed for livestock production. Ranches provide extensive wildlife habitat and generate multiple <span class="hlt">ecosystem</span> services that carry considerable market and non-market values. These rangelands are under pressure from urbanization and conversion to intensive agriculture, as well as from climate change that can alter the flow of these services. To understand the coupled and isolated impacts of land use and climate change on rangeland <span class="hlt">ecosystem</span> services, we developed six spatially explicit (250 m) coupled climate/land use/hydrological change scenarios for the Central Valley and oak woodland regions of <span class="hlt">California</span> consistent with three IPCC emission scenarios - A2, A1B and B1. Three land use land cover (LULC) change scenarios were each integrated with two downscaled global climate models (GCMs) (a warm, wet future and a hot, dry future) and related hydrologic data. We used these scenarios to quantify wildlife habitat, water supply (recharge potential and streamflow) and carbon sequestration on rangelands and to conduct an economic analysis associated with changes in these benefits. The USGS FOREcasting SCEnarios of land-use change model (FORE-SCE), which runs dynamically with downscaled GCM outputs, was used to generate maps of yearly LULC change for each scenario from 2006 to 2100. We used the USGS Basin Characterization Model (BCM), a regional water balance model, to generate change in runoff, recharge, and stream discharge based on land use change and climate change. Metrics derived from model outputs were generated at the landscape scale and for six case-study watersheds. At the landscape scale, over a quarter of the million acres set aside for conservation in the B1 scenario would otherwise be converted to agriculture in the A2 scenario, where temperatures increase by up to 4.5 °C compared to 1.3 °C in the B1 scenario. A comparison of two watersheds - Alameda Creek, an urbanized watershed, and Upper Stony Creek, impacted by intensified agriculture, demonstrates the relative contribution of urbanization and climate change to water supply. In Upper Stony Creek, where 24% of grassland is converted to agriculture in the A1B scenario, a hotter, dryer 4-year time period could lead to a 40% reduction in streamflow compared to present day. In Alameda Creek, for the same scenario, 47% of grassland is converted to urbanized lands and streamflow may increase by 11%, resulting in a recharge:runoff ratio of 0.26; though if urbanization does not take place, streamflow could decrease by 64% and the recharge:runoff ratio would be 1.2. Model outputs quantify the impact of urbanization on water supply and show the importance of soil storage capacity. Scenarios have applications for climate-smart conservation and land use planning by identifying outcomes associated with coupled future land use scenarios and more variable and extreme potential future climates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PrOce.138..381F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PrOce.138..381F"><span id="translatedtitle">The role of environmental controls in determining sardine and anchovy population cycles in the <span class="hlt">California</span> <span class="hlt">Current</span>: Analysis of an end-to-end model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fiechter, Jerome; Rose, Kenneth A.; Curchitser, Enrique N.; Hedstrom, Katherine S.</p> <p>2015-11-01</p> <p>Sardine and anchovy are two forage species of particular interest because of their low-frequency cycles in adult abundance in boundary <span class="hlt">current</span> regions, combined with a commercially relevant contribution to the global marine food catch. While several hypotheses have been put forth to explain decadal shifts in sardine and anchovy populations, a mechanistic basis for how the physics, biogeochemistry, and biology combine to produce patterns of synchronous variability across widely separated systems has remained elusive. The present study uses a 50-year (1959-2008) simulation of a fully coupled end-to-end <span class="hlt">ecosystem</span> model configured for sardine and anchovy in the <span class="hlt">California</span> <span class="hlt">Current</span> System to investigate how environmental processes control their population dynamics. The results illustrate that slightly different temperature and diet preferences can lead to significantly different responses to environmental variability. Simulated adult population fluctuations are associated with age-1 growth (via age-2 egg production) and prey availability for anchovy, while they depend primarily on age-0 survival and temperature for sardine. The analysis also hints at potential linkages to known modes of climate variability, whereby changes in adult abundance are related to ENSO for anchovy and to the PDO for sardine. The connection to the PDO and ENSO is consistent with modes of interannual and decadal variability that would alternatively favor anchovy during years of cooler temperatures and higher prey availability, and sardine during years of warmer temperatures and lower prey availability. While the end-to-end <span class="hlt">ecosystem</span> model provides valuable insight on potential relationships between environmental conditions and sardine and anchovy population dynamics, understanding the complex interplay, and potential lags, between the full array of processes controlling their abundances in the <span class="hlt">California</span> <span class="hlt">Current</span> System remains an on-going challenge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ERL....11a4007T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ERL....11a4007T"><span id="translatedtitle">Climatic modulation of recent trends in ocean acidification in the <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turi, G.; Lachkar, Z.; Gruber, N.; Münnich, M.</p> <p>2016-01-01</p> <p>We reconstruct the evolution of ocean acidification in the <span class="hlt">California</span> <span class="hlt">Current</span> System (CalCS) from 1979 through 2012 using hindcast simulations with an eddy-resolving ocean biogeochemical model forced with observation-based variations of wind and fluxes of heat and freshwater. We find that domain-wide pH and {{{Ω }}}{arag} in the top 60 m of the water column decreased significantly over these three decades by about ‑0.02 decade‑1 and ‑0.12 decade‑1, respectively. In the nearshore areas of northern <span class="hlt">California</span> and Oregon, ocean acidification is reconstructed to have progressed much more rapidly, with rates up to 30% higher than the domain-wide trends. Furthermore, ocean acidification penetrated substantially into the thermocline, causing a significant domain-wide shoaling of the aragonite saturation depth of on average ‑33 m decade‑1 and up to ‑50 m decade‑1 in the nearshore area of northern <span class="hlt">California</span>. This resulted in a coast-wide increase in nearly undersaturated waters and the appearance of waters with {{{Ω }}}{arag}\\lt 1, leading to a substantial reduction of habitat suitability. Averaged over the whole domain, the main driver of these trends is the oceanic uptake of anthropogenic CO2 from the atmosphere. However, recent changes in the climatic forcing have substantially modulated these trends regionally. This is particularly evident in the nearshore regions, where the total trends in pH are up to 50% larger and trends in {{{Ω }}}{arag} and in the aragonite saturation depth are even twice to three times larger than the purely atmospheric CO2-driven trends. This modulation in the nearshore regions is a result of the recent marked increase in alongshore wind stress, which brought elevated levels of dissolved inorganic carbon to the surface via upwelling. Our results demonstrate that changes in the climatic forcing need to be taken into consideration in future projections of the progression of ocean acidification in coastal upwelling regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMNH43B1656A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMNH43B1656A"><span id="translatedtitle">Observed and modeled tsunami <span class="hlt">current</span> velocities in Humboldt Bay and Crescent City Harbor, northern <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Admire, A. R.; Dengler, L.; Crawford, G. B.; uslu, B. U.; Montoya, J.</p> <p>2012-12-01</p> <p>A pilot project was initiated in 2009 in Humboldt Bay, about 370 kilometers (km) north of San Francisco, <span class="hlt">California</span>, to measure the <span class="hlt">currents</span> produced by tsunamis. Northern <span class="hlt">California</span> is susceptible to both near- and far-field tsunamis and has a historic record of damaging events. Crescent City Harbor, located approximately 100 km north of Humboldt Bay, suffered US 20 million in damages from strong <span class="hlt">currents</span> produced by the 2006 Kuril Islands tsunami and an additional US 20 million from the 2011 Japan tsunami. In order to better evaluate these <span class="hlt">currents</span> in northern <span class="hlt">California</span>, we deployed a Nortek Aquadopp 600kHz 2D Acoustic Doppler <span class="hlt">Current</span> Profiler (ADCP) with a one-minute sampling interval in Humboldt Bay, near the existing National Oceanic and Atmospheric Administration (NOAA) National Ocean Service (NOS) tide gauge station. The instrument recorded the tsunamis produced by the Mw 8.8 Chile earthquake on February 27, 2010 and the Mw 9.0 Japan earthquake on March 11, 2011. <span class="hlt">Currents</span> from the 2010 tsunami persisted in Humboldt Bay for at least 30 hours with peak amplitudes of about 0.3 meters per second (m/s). The 2011 tsunami signal lasted for over 86 hours with peak amplitude of 0.95 m/s. Strongest <span class="hlt">currents</span> corresponded to the maximum change in water level as recorded on the NOAA NOS tide gauge, and occurred 90 minutes after the initial wave arrival. No damage was observed in Humboldt Bay for either event. In Crescent City, <span class="hlt">currents</span> for the first three and a half hours of the 2011 Japan tsunami were estimated using security camera video footage from the Harbor Master building across from the entrance to the small boat basin, approximately 70 meters away from the NOAA NOS tide gauge station. The largest amplitude tide gauge water-level oscillations and most of the damage occurred within this time window. The <span class="hlt">currents</span> reached a velocity of approximately 4.5 m/s and six cycles exceeded 3 m/s during this period. Measured <span class="hlt">current</span> velocities both in Humboldt Bay and in Crescent City were compared to calculated velocities from the Method of Splitting Tsunamis (MOST) numerical model. For Humboldt Bay, the 2010 model tsunami frequencies matched the actual values for the first two hours after the initial arrival however the amplitudes were underestimated by approximately 65%. MOST replicated the first four hours of the 2011 tsunami signal in Humboldt Bay quite well although the peak flood <span class="hlt">currents</span> were underestimated by about 50%. MOST predicted attenuation of the signal after four hours but the actual signal persisted at a nearly constant level for more than 48 hours. In Crescent City, the model prediction of the 2011 frequency agreed quite well with the observed signal for the first two and a half hours after the initial arrival with a 50% underestimation of the peak amplitude. The results from this project demonstrate that ADCPs can effectively record tsunami <span class="hlt">currents</span> for small to moderate events and can be used to calibrate and validate models (i.e. MOST) in order to better predict hazardous tsunami conditions and improve planned responses to protect lives and property, especially within harbors. An ADCP will be installed in Crescent City Harbor and four additional ADCPs are being deployed in Humboldt Bay during the fall of 2012.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ECSS...89..191S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ECSS...89..191S"><span id="translatedtitle">Litterfall dynamics and nutrient decomposition of arid mangroves in the Gulf of <span class="hlt">California</span>: Their role sustaining <span class="hlt">ecosystem</span> heterotrophy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Snchez-Andrs, R.; Snchez-Carrillo, S.; Alatorre, L. C.; Cirujano, S.; lvarez-Cobelas, M.</p> <p>2010-10-01</p> <p>This study shows results on litterfall dynamics and decay in mangrove stands of Avicennia germinans distributed along a latitudinal gradient (three forest sites) in the Gulf of <span class="hlt">California</span>, in order to assess whether internal sources could support the observed mangrove <span class="hlt">ecosystem</span> organic deficit in this arid tropic. Total mean annual litterfall production increased southward (712.6 53.3, 1501.3 145.1 and 1506.2 280.5 g DW m -2 y -1, in the Yaqui, Mayo and Fuerte areas respectively), leaves being the main component of litter in all locations during the entire year, followed by fruits. The wet season (June-September) showed the highest litterfall rates through fruits. The temporal trend of litterfall production was significantly explained through mean air temperature ( R2 = 68%) whilst total annual litter production in the entire region showed a statistically significant relationship with total soil phosphorus, salinity, total nitrogen, organic matter and tree height ( R2 = 0.67). Throughout 117 days of the decomposition experiment, the litter lost 50% of its original dry weight in 5.8 days (average decay rate of 0.032 0.04 g DW d -1) and there were not significant differences in the remaining mass after 6 days. The percentage of both C and P released from the litter correlated significantly with the ratio of tidal inundated days to total experiment days ( R2 = 0.62, p = 0.03 and R2 = 0.67, p = 0.02, respectively); however, the frequency of tidal inundation only showed a significant increase in C release from Avicennia litter after 6 and above 48 days of decomposition. Whereas the total C content of litter bags decreased linearly over the decomposition to (% Total C = 5.52 - 0.46 days, R2 = 0.81, p = 0.0005), N content displayed an irregular pattern with a significant increase of decay between 48 and 76 days from the beginning of the experiment. The pattern for relative P content of litter revealed reductions of up to 99% of the original (%tot- P = -9.77 to 1.004 days, R2 = 0.72, p = 0.01) although most of the P reduction occurred between 17 and 34 days after the experiment started. Soil N and P contents, which exhibited significant differences in the course of the decomposition experiment, appeared to show significant differences between sampling sites, although they were not related to tidal influence, nor by leaf and nutrient leaching. In a global basis, C/ N litter ratios decreased linearly ( C/ N = 32.86 - 0.1006 days, R2 = 0.62, p = 0.02), showing a strong and significant correlation with meteorological variables ( R2 = 0.99, p = 0.01). C/ P ratios of litter increased through an exponential function ( C/ P = 119.35e 0.04day, R2 = 0.89, p < 0.001). Changes in the remaining percentage of litter mass during the experiment were significantly correlated with soil C/ N ratio ( R2 = 0.56, p = 0.03) as well as with the soil C/ P ratio ( R2 = 0.98, p < 0.001). Our results of litter decomposition dynamics in this mangrove support the fact of null net primary productivity of the arid mangrove wetlands: fast litter decomposition compensates the <span class="hlt">ecosystem</span> organic deficit in order to sustain the mangrove productivity. Litter decomposition plays a key role in the <span class="hlt">ecosystem</span> metabolism in mangroves of arid tropics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70010413','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70010413"><span id="translatedtitle">Coastal <span class="hlt">currents</span> and mass transport of surface sediments over the shelf regions of Monterey Bay, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wolf, S.C.</p> <p>1970-01-01</p> <p>In Monterey Bay, the highest concentrations of medium and fine sands occur nearshore between ten and thirty fathoms. Silt and clay accumulate in greater depths. Contours of median diameter roughly parallel the isobaths. Fine-grained materials are supplied to the bay region from erosion of cliffs which partly surround Monterey Bay, from sediment laden river discharge, and from continual reworking of widespread Pleistocene and Recent sea floor sediments. These sediments in turn are picked up by coastal <span class="hlt">currents</span> and distributed over the shelf regions by present day <span class="hlt">current</span> regimes. Studies of bottom <span class="hlt">currents</span> over the shelf regions and in Monterey Canyon have revealed patterns which vary with seasonal changes. <span class="hlt">Current</span> patterns during August and September exhibit remarkable symmetry about the axis of Monterey Submarine Canyon. Central Shelf <span class="hlt">currents</span> north and south of Monterey Canyon flowed northwest at an average rate of 0.2 knots and south at 0.3 knots respectively. On the North Shelf between January and March <span class="hlt">currents</span> flowed east to southeast at 0.3-0.5 knots with mirror image patterns above the South Shelf during the same period. Irregular <span class="hlt">current</span> flow in the canyon indicates a complex <span class="hlt">current</span> structure with frequent shifts in counterclockwise and clockwise direction over very short periods of time. Bottom topography of the canyon complex often causes localization of canyon <span class="hlt">currents</span>. One particular observation at a depth of 51 fathoms indicated up-canyon flow at a rate of 0.2 knots. Most of the observed <span class="hlt">currents</span> are related to seasonal variations, upwelling, ocean swell patterns, and to changes in the <span class="hlt">California</span> and Davidson <span class="hlt">currents</span>. Changes in <span class="hlt">current</span> regimes are reflected in the patterns of sediment distribution and transport. Sediment transport is chiefly parallel to the isobaths, particularly on the North and South Shelf regions. Complex dispersal patterns are observed near Monterey Canyon and Moss Landing Harbor jetties. Longshore <span class="hlt">currents</span> move sediments southward except near Monterey Canyon which acts as a physiographic barrier and the extreme southern end of the bay where <span class="hlt">currents</span> are non persistent. Some sediments are also transported offshore by rip <span class="hlt">currents</span> and other agencies and deposited in deeper, quieter waters. Supply of sediments to the canyon head results in over-filling and steepening with subsequent mass movement of sediments seaward followed by deposition in channels and on the broad deep sea fan. ?? 1970.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PrOce..79..366T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PrOce..79..366T"><span id="translatedtitle">Trophic modeling of the Northern Humboldt <span class="hlt">Current</span> <span class="hlt">Ecosystem</span>, Part II: Elucidating <span class="hlt">ecosystem</span> dynamics from 1995 to 2004 with a focus on the impact of ENSO</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taylor, Marc H.; Tam, Jorge; Blaskovic, Vernica; Espinoza, Pepe; Michael Balln, R.; Wosnitza-Mendo, Claudia; Argelles, Juan; Daz, Erich; Purca, Sara; Ochoa, Noemi; Ayn, Patricia; Goya, Elisa; Gutirrez, Dimitri; Quipuzcoa, Luis; Wolff, Matthias</p> <p>2008-10-01</p> <p>The Northern Humboldt <span class="hlt">Current</span> <span class="hlt">Ecosystem</span> is one of the most productive in the world in terms of fish production. Its location near to the equator permits strong upwelling under relatively low winds, thus creating optimal conditions for the development of plankton communities. These communities ultimately support abundant populations of grazing fish such as the Peruvian anchoveta, Engraulis ringens. The <span class="hlt">ecosystem</span> is also subject to strong inter-annual environmental variability associated with the El Nio Southern Oscillation (ENSO), which has major effects on nutrient structure, primary production, and higher trophic levels. Here our objective is to model the contributions of several external drivers (i.e. reconstructed phytoplankton changes, fish immigration, and fishing rate) and internal control mechanisms (i.e. predator-prey) to <span class="hlt">ecosystem</span> dynamics over an ENSO cycle. Steady-state models and time-series data from the Instituto del Mar del Per (IMARPE) from 1995 to 2004 provide the base data for simulations conducted with the program Ecopath with Ecosim. In simulations all three external drivers contribute to <span class="hlt">ecosystem</span> dynamics. Changes in phytoplankton quantity and composition (i.e. contribution of diatoms and dino- and silicoflagellates), as affected by upwelling intensity, were important in dynamics of the El Nio of 1997-98 and the subsequent 3 years. The expansion and immigration of mesopelagic fish populations during El Nio was important for dynamics in following years. Fishing rate changes were the most important of the three external drivers tested, helping to explain observed dynamics throughout the modeled period, and particularly during the post-El Nio period. Internal control settings show a mix of predator-prey control settings; however a wasp-waist control of the <span class="hlt">ecosystem</span> by small pelagic fish is not supported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PrOce.134..404L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PrOce.134..404L"><span id="translatedtitle">Large-scale forcing of environmental conditions on subarctic copepods in the northern <span class="hlt">California</span> <span class="hlt">Current</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Hui; Bi, Hongsheng; Peterson, William T.</p> <p>2015-05-01</p> <p>In the ocean, dominant physical processes often change at various spatial and temporal scales. Here, we examined associations between large-scale physical forcing indexed by the Pacific Decadal Oscillation (PDO), regional ocean conditions including alongshore <span class="hlt">currents</span> in relation to the abundance of two subarctic oceanic copepods, Neocalanus plumchrus, and N. cristatus in the offshore portions of the northern <span class="hlt">California</span> <span class="hlt">Current</span> (NCC) system in spring of 1998-2008. We found significant relationships between the abundance of copepods, water temperature, and alongshore <span class="hlt">currents</span> with a lag of two or four months in response to the PDO in the NCC system. During the growth season in March/April both subarctic copepod species displayed consistent cross-shelf patterns with shoreward decreasing gradient in abundance, and were negatively correlated with the PDO, sea water temperature, and alongshore <span class="hlt">currents</span>. Our studies highlight the responses of regional ocean conditions to large-scale physical forcing and illustrate the potential for Neocalanus copepods as unique vectors for a new understanding of the ecological response in the offshore oceanic waters of the NCC system to climate variability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5610248','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5610248"><span id="translatedtitle">/sup 234/Th: /sup 238/U disequilibria within the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Coale, K.H.; Bruland, K.W.</p> <p>1985-01-01</p> <p>Profiles of dissolved and particulate /sup 234/Th were determined at several stations within the <span class="hlt">California</span> <span class="hlt">Current</span>. Modeling of the disequilibria between the /sup 234/Th and /sup 238/U within the surface waters provides for estimates of the residence time of dissolved thorium with respect to particle scavenging, the particle residence time, and the particulate /sup 234/Th flux exiting the surface layer. The model-derived, first-order scavenging rate constant for dissolved thorium is observed to be proportional to the rate of primary production. Particle residence times seem to be governed by the rate of zooplankton grazing and the types of zooplankton present. Model-derived particulate /sup 234/Th fluxes are in good agreement with direct measurements by sediment traps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMOS53B1693M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMOS53B1693M"><span id="translatedtitle">Constraining the timing of turbidity <span class="hlt">current</span> driven sediment transport down Monterey Canyon, offshore <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McGann, M.; Stevens, T.; Paull, C. K.; Ussler, W.; Buylaert, J.</p> <p>2013-12-01</p> <p>Turbidity <span class="hlt">currents</span> are responsible for transport of sand down the Monterey Submarine Canyon, offshore <span class="hlt">California</span>, from the shoreline to Monterey Fan. However the timing of sediment transport events and their frequencies are not fully understood despite recent monitoring of canyon events and AMS 14C dating of foraminifera from hemipelagic sediments bracketing sand deposited during turbidity flows. Quartz optically stimulated luminescence (OSL) dating in sand sequences provides a complementary means of dating sand transport. OSL dates reflect the time interval since the sand grains were last exposed to sunlight. However, the technique has never been applied extensively to canyon sediments before. Here we report both quartz OSL ages of sand deposits and benthic foraminifera ages sampled from the axial channel within Monterey Submarine Canyon and Fan via ROV-collected vibracores. This allows a rare opportunity to directly test the frequency and timing of turbidity <span class="hlt">current</span> events at different points in the canyon. We use both single-grain and small (~2 mm area) single aliquot regeneration OSL approaches on vibracore samples from various water depths to determine sand transport frequency. Within the upper canyon (<2,000 m water depths) the OSL data require sub-decadal to decadal transit times. Sand bearing fining upward sequences yielding middle Holocene to last few hundred year ages indicate turbidity <span class="hlt">currents</span> occur at 150 to 250 year event frequencies within the fan channel out to 3,600 m water depth. We suggest that turbidity <span class="hlt">currents</span> have been active during the <span class="hlt">current</span> sea-level high stand and that the submarine fan has recorded turbidity <span class="hlt">currents</span> over the entire Holocene. The increased age spread in single grain OSL dates with water depth provides evidence of sediment mixing and reworking during turbidity flows. Apparently, sand is stored within the canyon for various amounts of time while it is in route to its <span class="hlt">current</span> location on the fan.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005DSRII..52..331B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005DSRII..52..331B"><span id="translatedtitle">Differences in dynamic response of <span class="hlt">California</span> <span class="hlt">Current</span> salmon species to changes in ocean conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Botsford, Louis W.; Lawrence, Cathryn A.; Forrest Hill, M.</p> <p>2005-01-01</p> <p>While changes in the northeast Pacific Ocean in the mid-1970s apparently caused changes in salmon population growth in the Gulf of Alaska and the <span class="hlt">California</span> <span class="hlt">Current</span>, the responses of <span class="hlt">California</span> <span class="hlt">Current</span> salmon species, coho salmon ( Oncorhynchus kisutch) and chinook salmon ( O. tshawytscha) differed. Coho salmon catches declined dramatically along the coasts of <span class="hlt">California</span>, Oregon and Washington, while chinook salmon catches did not. This provides an opportunity for comparative analysis, a rarity in the study of long-term changes in the ocean. Here we test one possible explanation for that difference, that chinook salmon populations are inherently more persistent because chinook salmon populations spawn over a range of ages, while coho salmon spawn predominantly at age 3 yr. We extended a previous theoretical approach that had been used to assess the long-term response of salmon populations with various spawning age structures to different means and variances in environmental variability. New results indicate that populations with environmental variability at the age of return to freshwater have the same characteristic identified earlier for populations with variability in the age of entry: populations spawning at multiple ages are more persistent, but that increased persistence is gained in the first few percent of departure from all spawning at a single age. Thus, in both cases the results are too sensitive to values of uncertain parameters to depend on as an explanation of the differences in response. We also approached this question by subjecting model populations with coho and chinook salmon spawning age structures to an empirical estimate of actual marine survival of coho salmon over the years 1970-2002, asking the question, if chinook salmon had been subjected to the same ocean survivals would they have experienced the same decline. The differences in spawning age structure made little difference in population responses. The dominant factor influencing the response of these species to a decline in ocean survival was the behavior of the freshwater spawner/smolt relationship at low abundance, a factor that has recently been intensively studied for coho salmon, but is poorly known for chinook salmon. These results suggest that the GLOBEC NEP should focus attention on the ocean phase of salmon life, to explain the observed difference in population response to changes in physical conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DSRII.112...91K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DSRII.112...91K"><span id="translatedtitle">Multi-satellite time series of inherent optical properties in the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kahru, Mati; Lee, Zhongping; Kudela, Raphael M.; Manzano-Sarabia, Marlenne; Greg Mitchell, B.</p> <p>2015-02-01</p> <p>Satellite ocean color radiometry is a powerful method to study ocean biology but the relationships between satellite measurements and the in situ ocean properties are not well understood. Moreover, the measurements made with one satellite sensor may not be directly compatible with similar measurements from another sensor. We estimate inherent optical properties (IOPs) in the <span class="hlt">California</span> <span class="hlt">Current</span> by applying empirically optimized versions of the Quasi-Analytical Algorithm (QAA) of Lee et al. (2002) to satellite remote sensing reflectance (Rrs) from four ocean color sensors (OCTS, SeaWiFS, MODISA and MERIS). The set of estimated IOPs includes the total absorption coefficient at 490 nm (a490), phytoplankton absorption coefficient at 440 nm (aph440), absorption by dissolved and detrital organic matter at 440 nm (adg440) and particle backscattering coefficient at 490 nm (bbp490). The empirical inversion models are created by minimizing the deviations between satellite match-ups with in situ measurements and between the estimates of individual overlapping satellite sensors. The derived empirical algorithms were then applied to satellite Level-3 daily Rrs to create merged multi-sensor time series of the near-surface optical characteristics in the <span class="hlt">California</span> <span class="hlt">Current</span> region for a time period of over 16 years (November 1996-December 2012). Due to the limited number of in situ match-ups and their uneven distribution as well as the large errors in the satellite-derived Rrs, the uncertainty in the retrieved IOPs is still significant and difficult to quantify. The merged time series show the dominant annual cycle but also significant variability at interannual time scales. The ratio of adg440 to aph440 is around 1 in the transition zone, is >1 in the coastal zone and generally <1 offshore. adg440 decreases towards south and towards offshore. The long-term (~16 years) trend in aph440, representative of phytoplankton biomass, shows a significant (P<0.01) increasing trend in a wide band (~500 km) along the coast and a significant decreasing trends in the oligotrophic North Pacific gyre. The trend of increasing aph440 in the upwelling areas off <span class="hlt">California</span> is positively correlated with the increasing wind speed along the coast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PrOce..83..107B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PrOce..83..107B"><span id="translatedtitle">Trophic structure and diversity in rocky intertidal upwelling <span class="hlt">ecosystems</span>: A comparison of community patterns across <span class="hlt">California</span>, Chile, South Africa and New Zealand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blanchette, C. A.; Wieters, E. A.; Broitman, B. R.; Kinlan, B. P.; Schiel, D. R.</p> <p>2009-12-01</p> <p>The Benguela, <span class="hlt">California</span>, and Humboldt represent three of the major eastern boundary upwelling <span class="hlt">ecosystems</span> in the world. Upwelling <span class="hlt">ecosystems</span> are highly productive, and this productivity forms the base of the food chain, potentially leading to <span class="hlt">ecosystems</span> similar in trophic structure and diversity among upwelling regions. Here we compare the biological and trophic structure of rocky intertidal communities in each of these major upwelling regions. Our comparison includes a fourth region, New Zealand, which spans a similar latitudinal range, and experiences intermittent upwelling. The influence of oceanographic conditions on these communities was evaluated by using the long-term mean and standard deviation of satellite-based sea surface temperature (SST). Large differences emerged in the taxonomic richness in each of these systems, with <span class="hlt">California</span> as the most and the Humboldt as the least taxonomically rich. Across all regions, richness tended to decrease progressively from lower trophic levels (macrophytes) to higher trophic levels (carnivores), and richness was inversely correlated with the proportion of variance in SST contained in the seasonal cycle, suggesting that strongly seasonal, predictable environments are relatively low in diversity. The functional and trophic structures were remarkably similar across these four regions of the world. Macrophytes were slightly dominant over filter-feeders in terms of space occupancy in all regions except the Benguela. Densities of herbivorous grazers were greatest in <span class="hlt">California</span> and Benguela and far outnumbered carnivore densities in all regions. Despite some similarities, the overall structure of the communities from these regions differed significantly supporting the hypothesis that the biological and ecological consequences of similar physical forcing mechanisms (e.g. upwelling) are likely to be context-dependent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70031952','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70031952"><span id="translatedtitle">Rapid formation of hyperpycnal sediment gravity <span class="hlt">currents</span> offshore of a semi-arid <span class="hlt">California</span> river</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Warrick, J.A.; Xu, Jie; Noble, M.A.; Lee, H.J.</p> <p>2008-01-01</p> <p>Observations of sediment dispersal from the Santa Clara River of southern <span class="hlt">California</span> during two moderately sized river discharge events suggest that river sediment rapidly formed a negatively buoyant (hyperpycnal) bottom plume along the seabed within hours of peak discharge. An array of acoustic and optical sensors were placed at three stations 1 km from the Santa Clara River mouth in 10-m water depth during January-February 2004. These combined observations suggest that fluid mud concentrations of suspended sediment (>10 g/l) and across-shore gravity <span class="hlt">currents</span> (???5 cm/s) were observed in the lower 20-40 cm of the water column 4-6 h after discharge events. Gravity <span class="hlt">currents</span> were wave dominated, rather than auto-suspending, and appeared to consist of silt-to-clay sized sediment from the river. Sediment mass balances suggest that 25-50% of the discharged river sediment was transported by these hyperpycnal <span class="hlt">currents</span>. Sediment settling purely by flocs (???1 mm/s) cannot explain the formation of the observed hyperpycnal plumes, therefore we suggest that some enhanced sediment settling from mixing, convective instabilities, or diverging plumes occurred that would explain the formation of the gravity <span class="hlt">currents</span>. These combined results provide field evidence that high suspended-sediment concentrations from rivers (>1 g/l) may rapidly form hyperpycnal sediment gravity <span class="hlt">currents</span> immediately offshore of river mouths, and these pathways can explain a significant portion of the river-margin sediment budget. The fate of this sediment will be strongly influenced by bathymetry, whereas the fate of the remaining sediment will be much more influenced by ocean <span class="hlt">currents</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSMNB21F..01L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSMNB21F..01L"><span id="translatedtitle">Towards Sustaining Water Resources and Aquatic <span class="hlt">Ecosystems</span>: Forecasting Watershed Risks to <span class="hlt">Current</span> and Future Land Use Change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lohse, K. A.; Newburn, D.; Opperman, J. J.; Brooks, C.; Merenlender, A.</p> <p>2005-05-01</p> <p>Sustaining aquatic resources requires managing existing threats and anticipating future impacts. Resource managers and planners often have limited understanding of the relative effects of human activities on stream conditions and how these effects will change over time. Here we assess and forecast the relative impacts of land use on sediment concentrations in Mediterranean-climate watersheds in <span class="hlt">California</span>. We focus on the Russian River basin, which supports threatened salmonid populations vulnerable to high levels of fine sediment. We ask the following questions: (1) What are the relative impacts of three different land uses (urban, exurban and agriculture) on the patterns of fine sediment in streams? (2) What is the relative contribution of past and <span class="hlt">current</span> changes in land use activities on these patterns? and (3) What are the effects of future development on these sediment levels? First, we characterized land use at the parcel scale to calibrate the relative impacts of exurban and urban land use on stream substrate quality, characterized by the concentration of fine sediment surrounding spawning gravels (`embeddedness') in 105 stream reaches. Second, we built multiple ordinal logistic regression models on a subset of watersheds (n=64) and then evaluated substrate quality predictions against observed data from another set of watersheds (n=41). Finally, we coupled these models with spatially explicit land use change models to project future stream conditions and associated uncertainties under different development scenarios for the year 2010. We found that the percent of urban housing and agriculture were significant predictors of in-stream embeddedness. Model results from parcel-level land use data indicated that changes in development were better predictors of fine sediment than total development in a single time period. In addition, our results indicate that exurban development is an important threat to stream systems; increases in the percent of total exurban development in a watershed significantly reduced the odds of observing low embeddedness. Our 2010 forecasts highlight the sensitivity of watersheds to small changes in exurban growth. In previously unimpaired watersheds, small increases in future exurban growth resulted in cumulative impacts on substrate quality not predicted by models lacking this land use type. Because most previous analyses have characterized land use at a resolution that cannot capture exurban development, these results suggest that many such models may be missing an important type of development that can adversely impacting aquatic <span class="hlt">ecosystems</span>. We suggest that parcel level data may be the fundamental unit for land use change analysis because it represents the economic decision unit for land owners and resolves issues of geographical scale and boundary issues that have long hampered progress in ecological forecasting.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JGRG..116.1031G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JGRG..116.1031G"><span id="translatedtitle">Ecological controls on net <span class="hlt">ecosystem</span> productivity of a mesic arctic tundra under <span class="hlt">current</span> and future climates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grant, R. F.; Humphreys, E. R.; Lafleur, P. M.; Dimitrov, D. D.</p> <p>2011-03-01</p> <p>Changes in arctic C stocks with climate are thought to be caused by rising net primary productivity (NPP) during longer and warmer growing seasons, offset by rising heterotrophic respiration (Rh) in warmer and deeper soil active layers. In this study, we used the process model ecosys to test hypotheses for these changes with CO2 and energy fluxes measured by eddy covariance over a mesic shrub tundra at Daring Lake, Canada, under varying growing seasons. These tests corroborated substantial rises in NPP, smaller rises in Rh, and, hence, rises in net <span class="hlt">ecosystem</span> productivity (NEP) from 17 to 45 g C m-2 yr-1 (net C sink), modeled with higher Ta and longer growing seasons. However, NEP was found to decline briefly during midsummer warming events (Ta > 20C). A model run under climate change predicted for Daring Lake indicated that rises in NPP would exceed those in Rh during the first 100 years, causing NEP to rise. Rises in NPP were driven by more rapid net N mineralization from more rapid Rh in warming soils. However, greater declines in NEP were modeled during more frequent and intense midsummer warming events as climate change progressed. Consequently, average annual NEP ( interannual variability) rose from 30 (13) g C m-2 yr-1 under <span class="hlt">current</span> climate to 57 (40) g C m-2 yr-1 after 90 years but declined to 44 (51) g C m-2 yr-1 after 150 years, indicating that gains in tundra NEP under climate change may not be indefinite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B43C0507W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B43C0507W"><span id="translatedtitle">Climatic impacts on phenology in chaparral- and coastal sage scrub-dominated <span class="hlt">ecosystems</span> in southern <span class="hlt">California</span> using MODIS-derived time series</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Willis, K. S.; Gillespie, T.; Okin, G. S.; MacDonald, G. M.</p> <p>2013-12-01</p> <p>Remote sensing monitoring of vegetation phenology can be an important tool for detecting the impacts of climate change on whole <span class="hlt">ecosystem</span> functioning at local to regional scales. This study elucidates climate-phenology relations and the changes occurring in the phenology of both chaparral and coastal sage scrub-dominated <span class="hlt">ecosystems</span> in southern <span class="hlt">California</span>. Whole <span class="hlt">ecosystem</span> phenology is monitored for the period 2001-2012 using the Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) derived from MODIS MOD13Q1. Changes in phenology are assessed through a comparison of the time series with temperature, precipitation, and Palmer Drought Severity Index (PDSI) data and by computing time series phenology metrics. Overall we find that the vegetation index values have fluctuated around a stable mean for vegetation types for the entire time period. However, interannual variability is high, likely due to annual variations in climate. The most significant statistical correlation in chaparral <span class="hlt">ecosystems</span> were found between NDVI and PDSI, indicating that chaparral phenology is likely driven by drought and soil water deficit at the multi-monthly timescale. However, coastal sage scrub correlations were highest between NDVI and temperature + precipitation combined with no time lag. This reflects a more immediate response by these shallow rooted and deciduous species. The start of the growing season in both plant communities occurred early in rainy years, and later in years with lower PDSI (drought-associated). This suggests that future predicted climate change in southern <span class="hlt">California</span> may cause increased interannual variability in chaparral phenology cycles, with early initiation of the growing season occurring in years following large rain events, and later initiation in drought years. Coastal sage scrub-dominated areas will be less influenced by lower frequency, long-term drought, but more immediately affected by discrete precipitation events and timing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PrOce..83...65M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PrOce..83...65M"><span id="translatedtitle">The Humboldt <span class="hlt">Current</span> System: <span class="hlt">Ecosystem</span> components and processes, fisheries, and sediment studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Montecino, Vivian; Lange, Carina B.</p> <p>2009-12-01</p> <p>In the Humboldt <span class="hlt">Current</span> System (HCS), biological and non-biological components, <span class="hlt">ecosystem</span> processes, and fisheries are known to be affected by multi-decadal, inter-annual, annual, and intra-seasonal scales. The interplay between atmospheric variability, the poleward undercurrent, the shallow oxygen minimum zone (OMZ), and the fertilizing effect of coastal upwelling and overall high primary production rates drive bio-physical interactions, the carbon biomass, and fluxes of gases and particulate and dissolved matter through the water column. Coastal upwelling (permanent and seasonally modulated off Peru and northern Chile, and markedly seasonal between 30S and 40S) is the key process responsible for the high biological productivity in the HCS. At present, the western coast of South America produces more fish per unit area than any other region in the world ocean (i.e. ?7.5 10 6 t of anchoveta were landed in 2007). Climate changes on different temporal scales lead to alterations in the distribution ranges of anchoveta and sardine populations and shifts in their dominance throughout the HCS. The factors affecting the coastal marine <span class="hlt">ecosystem</span> that reverberate in the fisheries are crucial from a social perspective, since the economic consequences of mismanagement can be severe. Fish remains are often well-preserved in sediment settings under the hypoxic conditions of the OMZ off Peru and Chile, and reveal multi-decadal variability and centennial-scale changes in fish populations. Sediment studies from the Chilean continental margin encompassing the last 20,000 years of deposition reveal changes in sub-surface conditions in the HCS during deglaciation, interpreted to include: a major reorganization of the OMZ; a deglacial increase in denitrification decoupled from local marine productivity; and higher deglacial and Holocene paleoproductivities compared to the Last Glacial Maximum in central-south Chile (35-37S) while this scheme is reversed for north-central Chile. Multi-scale, interdisciplinary approaches and focused research groups are needed to understand air-sea interactions, plankton dynamics, biomass removal by fisheries, and the transformation and fluxes of matter across the different HCS components. In this paper, we present a multidisciplinary synthesis of the HCS that covers its physics, atmosphere, primary and secondary production, medium and high trophic levels, fisheries including management aspects, and relevant sedimentary studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H31H0718C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H31H0718C"><span id="translatedtitle">Characterizing changes in streamflow under historical and <span class="hlt">current</span> climates for the Russian River, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Curtis, J.; Flint, L. E.</p> <p>2014-12-01</p> <p>Precipitation in <span class="hlt">California</span> is naturally more variable than elsewhere in the United States, and climate change is expected to increase the frequency and severity of precipitation and streamflow anomalies. As part of a larger effort to assess flow conditions under historical, <span class="hlt">current</span>, and future climates, we characterized the change in the Russian River's mainstem flows between two 30-year periods that represent historical (1951 to 1980) and <span class="hlt">current</span> (1981 to 2010) climate conditions. Analyses included measured data from one mainstem gage (Ukiah) that represents natural flow conditions, and three mainstem gages (Hopland, Healdsburg, and Guerneville) regulated by diversion into the Russian River from the adjacent Eel River and by reservoir storage. Analysis of natural flows at the Ukiah gage under the <span class="hlt">current</span> climate indicates statistically significant increases in low flow metrics that include: median monthly flows from July to October; number of zero flow days; and 1-, 3-, 5-, 7-, 30- and 90-day minimum flows. In contrast to the Ukiah gage, decreases in low flows under the <span class="hlt">current</span> climate at the three regulated-streamflow gages varied with distance downstream. Statistically significant declines in median monthly flows occurred during the second period (1981-2010) from August to November at Hopland, September to November at Healdsburg and in October at Guerneville. Although mean annual flow declined at all four gages during the second period and median monthly low flows declined at the downstream gages, median monthly low flows and minimum flows at the Ukiah gage which represents natural flows increased during the driest months (July to October). Results from this study will be used to support ecological studies and water resource planning within the Russian River watershed. The relative importance of climate and watershed response on the quality and quantity of streamflow under historical and <span class="hlt">current</span> climates will be assessed and results compared to analyses of unimpaired flows estimated using a basin-scale water balance model calibrated to low flow conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003DSRII..50.2583R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003DSRII..50.2583R"><span id="translatedtitle">Long-term change and stability in the <span class="hlt">California</span> <span class="hlt">Current</span> System: lessons from CalCOFI and other long-term data sets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rebstock, Ginger A.</p> <p>2003-08-01</p> <p>The <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS) is a highly variable system, both spatially and temporally, that is strongly affected by low-frequency climatic fluctuations. This paper reviews evidence for long-term (decadal-scale) change in the physics and biology of the CCS over the last 50-100 years, as well as evidence for stability in planktonic community structure and long-term persistence of populations. Increases in water temperature, thermocline depth and stratification in the CCS have been accompanied by changes in populations of kelp, diatoms, foraminifera, radiolarians, intertidal invertebrates, zooplankton, fish and seabirds. However, there is also evidence for stability in assemblages of larval fish, calanoid copepods and radiolarians. Statistical averaging (the portfolio effect) may explain some aspects of stability in assemblages. Advection of planktonic populations may account for rapid recovery of biomass and dominance structure following perturbations such as strong El Nio events. Planktonic populations in the CCS may be adapted to large-scale biotic and abiotic variability, through a combination of advection of populations and life history traits. Several lessons may be learned from the <span class="hlt">California</span> Cooperative Oceanic Fisheries Investigations and other long-term data sets: (1) long time series are needed to understand the dynamics of the <span class="hlt">ecosystem</span>; (2) life histories are important determinants of species responses to environmental forcing, even in the plankton; and (3) the CCS is simultaneously variable and stable, and these properties are not necessarily in conflict.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PrOce..83..386T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PrOce..83..386T"><span id="translatedtitle">Interannual variability in chlorophyll concentrations in the Humboldt and <span class="hlt">California</span> <span class="hlt">Current</span> Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomas, Andrew C.; Brickley, Peter; Weatherbee, Ryan</p> <p>2009-12-01</p> <p>SeaWiFS data provide the first systematic comparison of 10 years (1997-2007) of chlorophyll interannual variability over the <span class="hlt">California</span> (CCS) and Humboldt (HCS) <span class="hlt">Current</span> Systems. Dominant signals are adjacent to the coast in the wind-driven upwelling zone. Maximum anomalies in both systems are negative signals during the 1997-1998 El Nio that persist into 1999 at most latitudes. Thereafter, anomalies primarily appear to be associated with shifts in phenology, with those in the CCS stronger than those of the HSC. Prominent signals in the CCS are positive anomalies in 2001-2002 at latitudes >35N and <30N, and in 2005-2006 from ?30 to 45N that persist at latitudes >40N into 2007. In the HCS, latitudinally extensive positive events occur in austral summers of 2002-2003, 2003-2004. Relationships of chlorophyll anomalies to forcing are explored through correlations to local upwelling anomalies and three indices of Pacific Ocean basin-scale variability, the Multivariate El Nio Index (MEI), the Pacific Decadal Oscillation (PDO) and the North Pacific Gyre Oscillation (NPGO). These show that each system has strong latitudinal regionality in linkage to forcing. At higher latitudes, correlations follow expected relationships of increased (decreased) chlorophyll with positive upwelling and NPGO (MEI and PDO). At specific latitudes, notably the Southern <span class="hlt">California</span> Bight and off Peru, where circulation and/or chlorophyll phenology differ from canonical EBUS patterns, correlations weaken or oppose those expected. Correlations excluding the El Nio period remain similar in the CCS but substantially changed in the HCS, indicating much stronger domination of El Nio conditions on HCS anomaly relationships over this 10-year period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21265453','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21265453"><span id="translatedtitle">Estimating the impacts of fishing on dependent predators: a case study in the <span class="hlt">California</span> <span class="hlt">Current</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Field, J C; MacCall, A D; Bradley, R W; Sydeman, W J</p> <p>2010-12-01</p> <p>Juvenile rockfish (Sebastes spp.) are important prey to seabirds in the <span class="hlt">California</span> <span class="hlt">Current</span> System, particularly during the breeding season. Both seabird breeding success and the abundance of pelagic juvenile rockfish show high interannual variability. This covariation is largely a response to variable ocean conditions; however, fishing on adult rockfish may have had consequences for seabird productivity (e.g., the number of chicks fledged per breeding pair) by reducing the availability of juvenile rockfish to provisioning seabird parents. We tested the hypothesis that fishing has decreased juvenile rockfish availability and thereby limited seabird productivity over the past 30 years. We quantified relationships between observed juvenile rockfish relative abundance and seabird productivity, used fisheries stock assessment approaches to estimate the relative abundance of juvenile rockfish in the absence of fishing, and compared the differences in seabird productivity that would have resulted without rockfish fisheries. We examined the abundance of juvenile rockfish and the corresponding productivity of three seabird species breeding on Southeast Farallon Island (near San Francisco, <span class="hlt">California</span>, USA) from the early 1980s to the present. Results show that while the relative abundance of juvenile rockfish has declined to approximately 50% of the estimated unfished biomass, seabirds achieved 75-95% of the estimated un-impacted levels of productivity, depending upon the species of bird and various model assumptions. These results primarily reflect seabirds with "conservative" life histories (one egg laid per year) and may be different for species with more flexible life history strategies (greater reproductive effort). Our results are consistent with the premise that the impacts of local rockfish fisheries on seabird productivity are less than impacts that have occurred to the prey resources themselves due to ocean climate and the ability of seabirds to buffer against changes in prey availability through prey-switching and other behavioral mechanisms. PMID:21265453</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6720942','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6720942"><span id="translatedtitle">Energy from <span class="hlt">California</span> agriculture and forest resources: <span class="hlt">current</span> and future potential and constraints</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sachs, R.H.</p> <p>1981-01-01</p> <p>More than 0.3 Quad of energy in the form of liquid, solid, and gaseous fuels can be produced from <span class="hlt">California</span> forests and farms without altering significantly the supply of food, feed or fiber. The costs of biomass to fuels via direct combustion and gasification conversion systems is now lower than the petroleum or natural gas-derived fuels that they would replace. Yields of 10 tons dry matter per acre per year would be expected from all irrigated agricultural regions if the most productive crops such as corn, sorghum, sugar beets, certain forages and tree crops are grown. Double cropping, e.g., winter grain followed by corn or sorghum in the summer, may increase yields above 10 tons dry matter per year. As much as 4 tons per acre should be available as residues from corn or sorghum for energy conversion systems. With selected crop acreage and utilization schemes up to 5 billion gallons of fermentation ethanol can be produced annually from high starch and sugar crops. With little change in <span class="hlt">current</span> crop production and utilization over 1 billion gallons of ethanol and methanol can be produced by conversion of <span class="hlt">current</span> collectable crop, forestry and urban residues.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DSRI..100..127W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DSRI..100..127W"><span id="translatedtitle">Transport patterns of Pacific sardine Sardinops sagax eggs and larvae in the <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weber, Edward D.; Chao, Yi; Chai, Fei; McClatchie, Sam</p> <p>2015-06-01</p> <p>We simulated transport of Pacific sardine eggs captured offshore of <span class="hlt">California</span> in spring of 2001-2012 using a regional ocean circulation model. Eggs were assumed to have developed into larvae within a few days and were modeled using five behavioral patterns: passive transport, diel vertical migration, diel vertical migration combined with swimming against the <span class="hlt">current</span>, diel migration combined with migration toward shore, and diel migration combined with migration toward the best habitat. Simulated larvae with no swimming behavior were advected far offshore to poor habitat where they were unlikely to survive. Diel vertical migration resulted in less offshore transport because larvae were less affected by surface <span class="hlt">currents</span> during the day. However, in half the years simulated nearly all juveniles were also located in poor habitat by late summer in this scenario. Swimming against the <span class="hlt">current</span> combined with diel vertical migration resulted in similar transport patterns to the diel-vertical-migration scenario because <span class="hlt">currents</span> dominated the transport of eggs and small larvae during the spring and early summer. Migration toward shore resulted in a large fraction of juveniles being located in appropriate habitat during late summer in all years. Migration toward the best habitat was the best strategy modeled. This strategy resulted in a slightly greater proportion of larvae being located in appropriate habitat at the end of summer than the swimming-toward-shore scenario, despite the fact that most larvae were located farther offshore. These results suggest that larval sardine might use directed horizontal swimming behavior to remain in suitable habitat conditions. A large fraction of larvae were transported south into Mexican waters by late summer in all five scenarios. Surveying juvenile sardines in fall near the border of the U.S. and Mexico may be an efficient means of estimating recruitment because the advection pattern of eggs and larvae to the south is opposite the adult migration pattern to the north. This pattern may cause juveniles to be spatially segregated from adults at the time they are being recruited.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70030038','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70030038"><span id="translatedtitle">Development of the <span class="hlt">California</span> <span class="hlt">Current</span> during the past 12,000 yr based on diatoms and silicoflagellates</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Barron, John A.; Bukry, David</p> <p>2007-01-01</p> <p>Detailed diatom and silicoflagellates records in three cores from the offshore region of southern Oregon to central <span class="hlt">California</span> reveal the evolution of the northern part of the <span class="hlt">California</span> <span class="hlt">Current</span> during the past 12,000 yr. The early Holocene, prior to ∼ 9 ka, was characterized by relatively warm sea surface temperatures (SST), owing to enhanced northerly flow of the subtropical waters comparable to the modern Davidson <span class="hlt">Current</span>. Progressive strengthening of the North Pacific High lead to intensification of the southward flow of the <span class="hlt">California</span> <span class="hlt">Current</span> at ∼ 8 ka, resulting in increased coastal upwelling and relatively cooler SST which persisted until ∼ 5 ka. Reduced southward flow of the <span class="hlt">California</span> <span class="hlt">Current</span> between ∼ 4.8 ka and 3.6 ka may have been responsible for a period of decreased upwelling. Modern seasonal oceanographic cycles, as evidenced by increased spring–early summer coastal upwelling and warming of early fall SST evolved between 3.5 and 3.2 ka. Widespread occurrence of paleoceanographic and paleoclimatic change between ∼ 3.5–3.0 ka along the eastern margins of the North Pacific was likely a response to increasing ENSO variability in the tropical Pacific.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70161741','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70161741"><span id="translatedtitle">Fire effects on aquatic <span class="hlt">ecosystems</span>: an assessment of the <span class="hlt">current</span> state of the science</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Rebecca J. Bixby; Scott D. Cooper; Gresswell, Bob; Lee E. Brown; Clifford N. Dahm; Kathleen A. Dwire</p> <p>2015-01-01</p> <p>Fire is a prevalent feature of many landscapes and has numerous and complex effects on geological, hydrological, ecological, and economic systems. In some regions, the frequency and intensity of wildfire have increased in recent years and are projected to escalate with predicted climatic and landuse changes. In addition, prescribed burns continue to be used in many parts of the world to clear vegetation for development projects, encourage desired vegetation, and reduce fuel loads. Given the prevalence of fire on the landscape, authors of papers in this special series examine the complexities of fire as a disturbance shaping freshwater <span class="hlt">ecosystems</span> and highlight the state of the science. These papers cover key aspects of fire effects that range from vegetation loss and recovery in watersheds to effects on hydrology and water quality with consequences for communities (from algae to fish), food webs, and <span class="hlt">ecosystem</span> processes (e.g., organic matter subsidies, nutrient cycling) across a range of scales. The results presented in this special series of articles expand our knowledge of fire effects in different biomes, water bodies, and geographic regions, encompassing aquatic population, community, and <span class="hlt">ecosystem</span> responses. In this overview, we summarize each paper and emphasize its contributions to knowledge on fire ecology and freshwater <span class="hlt">ecosystems</span>. This overview concludes with a list of 7 research foci that are needed to further our knowledge of fire effects on aquatic <span class="hlt">ecosystems</span>, including research on: 1) additional biomes and geographic regions; 2) additional habitats, including wetlands and lacustrine <span class="hlt">ecosystems</span>; 3) different fire severities, sizes, and spatial configurations; and 4) additional response variables (e.g., <span class="hlt">ecosystem</span> processes) 5) over long (>5 y) time scales 6) with more rigorous study designs and data analyses, and 7) consideration of the effects of fire management practices and policies on aquatic <span class="hlt">ecosystems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016BGeo...13..675Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016BGeo...13..675Y"><span id="translatedtitle">How have past fire disturbances contributed to the <span class="hlt">current</span> carbon balance of boreal <span class="hlt">ecosystems</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yue, C.; Ciais, P.; Zhu, D.; Wang, T.; Peng, S. S.; Piao, S. L.</p> <p>2016-02-01</p> <p>Boreal fires have immediate effects on regional carbon budgets by emitting CO2 into the atmosphere at the time of burning, but they also have legacy effects by initiating a long-term carbon sink during post-fire vegetation recovery. Quantifying these different effects on the <span class="hlt">current</span>-day pan-boreal (44-84° N) carbon balance and quantifying relative contributions of legacy sinks by past fires is important for understanding and predicting the carbon dynamics in this region. Here we used the global dynamic vegetation model ORCHIDEE-SPITFIRE (Organising Carbon and Hydrology In Dynamic <span class="hlt">Ecosystems</span> - SPread and InTensity of FIRE) to attribute the contributions by fires in different decades between 1850 and 2009 to the carbon balance of 2000-2009, taking into account the atmospheric CO2 change and climate change since 1850. The fire module of ORCHIDEE-SPITFIRE was turned off for each decade in turn and was also turned off before and after the decade in question in order to model the legacy carbon trajectory by fires in each past decade. We found that, unsurprisingly, fires that occurred in 2000-2009 are a carbon source (-0.17 Pg C yr-1) for the carbon balance of 2000-2009, whereas fires in all decades before 2000 contribute carbon sinks with a collective contribution of 0.23 Pg C yr-1. This leaves a net fire sink effect of 0.06 Pg C yr-1, or 6.3 % of the simulated regional carbon sink (0.95 Pg C yr-1). Further, fires with an age of 10-40 years (i.e., those that occurred during 1960-1999) contribute more than half of the total sink effect of fires. The small net sink effect of fires indicates that <span class="hlt">current</span>-day fire emissions are roughly balanced out by legacy sinks. The future role of fires in the regional carbon balance remains uncertain and will depend on whether changes in fires and associated carbon emissions will exceed the enhanced sink effects of previous fires, both being strongly affected by global change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PrOce.102...19R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PrOce.102...19R"><span id="translatedtitle">Interannual variability in the Northern <span class="hlt">California</span> <span class="hlt">Current</span> food web structure: Changes in energy flow pathways and the role of forage fish, euphausiids, and jellyfish</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ruzicka, James J.; Brodeur, Richard D.; Emmett, Robert L.; Steele, John H.; Zamon, Jeannette E.; Morgan, Cheryl A.; Thomas, Andrew C.; Wainwright, Thomas C.</p> <p>2012-09-01</p> <p>The Northern <span class="hlt">California</span> <span class="hlt">Current</span> (NCC) is a seasonally productive and open <span class="hlt">ecosystem</span>. It is home to both a diverse endemic community and to seasonally transient species. Productivity and food web structure vary seasonally, interannually, and decadally due to variability in coastal upwelling, climate-scale physical processes, and the migratory species entering the system. The composition of the pelagic community varies between years, including changes to mid-trophic level groups that represent alternate energy-transfer pathways between lower and upper trophic levels (forage fishes, euphausiids, jellyfish). Multiple data sets, including annual spring and summer mesoscale surveys of the zooplankton, pelagic fish, and seabird communities, were used to infer NCC trophic network arrangements and develop end-to-end models for each of the 2003-2007 upwelling seasons. Each model was used to quantify the interannual variability in energy-transfer efficiency from bottom to top trophic levels. When each model was driven under an identical nutrient input rate, substantial differences in the energy available to each functional group were evident. Scenario analyses were used to examine the roles of forage fishes, euphausiids, and jellyfish (small gelatinous zooplankton and large carnivorous jellyfish) as alternate energy transfer pathways. Euphausiids were the more important energy transfer pathway; a large proportion of the lower trophic production consumed was transferred to higher trophic levels. In contrast, jellyfish acted as a production loss pathway; little of the production consumed was passed upwards. Analysis of the range of <span class="hlt">ecosystem</span> states observed interannually and understanding system sensitivity to variability among key trophic groups improves our ability to predict NCC <span class="hlt">ecosystem</span> response to short- and long-term environmental change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMS...146...99C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMS...146...99C"><span id="translatedtitle">Temporal and sex-specific variability in Rhinoceros Auklet diet in the central <span class="hlt">California</span> <span class="hlt">Current</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carle, Ryan D.; Beck, Jessie N.; Calleri, David M.; Hester, Michelle M.</p> <p>2015-06-01</p> <p>We used stable isotopes (δ15N and δ13C) and compared prey provided to chicks by each sex to evaluate seasonal and sex-specific diets in Rhinoceros Auklets (Cerorhinca monocerata) in the central <span class="hlt">California</span> <span class="hlt">Current</span> system during 2012-2013. Mixing models indicated northern anchovy (Engraulis mordax) were important prey for adults during fall/winter and juvenile rockfishes (Sebastes spp.) were important prey during incubation both years. Adult trophic level increased between incubation and chick-rearing periods in both years. During 2012, δ15N and δ13C of chick-rearing males and females differed significantly; mixing models indicated that females ate more Pacific saury (Cololabis saira) and less market squid (Doryteuthis opalescens) than males. Likewise, females delivered significantly more Pacific saury and less market squid to chicks than males during 2012. Chick growth (g d- 1) and chick survival to fledging were significantly lower during 2012 than 2013, likely because chicks were fed lesser quality prey or fed less frequently in 2012. Lesser body mass of females during incubation in 2012 indicated sex-specific diet differences may have been related to female energetic constraints. The observed variability in Rhinoceros Auklet diet underscores the importance of managing multiple prey populations in this system so that generalist predators have sufficient resources through changing conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70015716','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70015716"><span id="translatedtitle">Emergence of burrowing urchins from <span class="hlt">California</span> continental shelf sediments-A response to alongshore <span class="hlt">current</span> reversals?</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nichols, F.H.; Cacchione, D.A.; Drake, D.E.; Thompson, J.K.</p> <p>1989-01-01</p> <p>Two sequences of bottom photographs taken every two or four hours for two months during the Coastal Ocean Dynamics Experiment (CODE) off the Russian River, <span class="hlt">California</span>, reveal the dynamic nature of interations between the water column, the sediments, and benthic organisms in the mid-shelf silt deposit. Time-lapse photographs taken between late spring and early summer in 1981 and 1982 show that the subsurface-dwelling urchin Brisaster latifrons (one of the largest invertebrates found in shelf-depth fine sediment off the U.S. Pacific coast) occasionally emerged from the sediment, plowed the sediment surface during the course of a few hours to several days, then buried themselves again. Frame-by-frame study of the film sequences shows that the urchins typically emerged following relaxation of coastal upwelling, periods characterized by <span class="hlt">current</span> direction reversals and increases in bottom water turbidity. Among the possible causes of the emergence of urchins and the consequent bioturbation of the upper few cm of sediment, a response to an enhanced food supply seems most plausible. Circumstantial evidence suggests the possibility that phytoplankton sedimentation during periods of upwelling relaxation could provide a new source of food at the sediment surface. ?? 1989.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740004025','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740004025"><span id="translatedtitle"><span class="hlt">California</span> coast nearshore processes study. [nearshore <span class="hlt">currents</span>, sediment transport, estuaries, and river discharge</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pirie, D. M.; Steller, D. D. (Principal Investigator)</p> <p>1973-01-01</p> <p>The author has identified the following significant results. Large scale sediment plumes from intermittent streams and rivers form detectable seasonal patterns on ERTS-1 imagery. The ocean <span class="hlt">current</span> systems, as plotted from three <span class="hlt">California</span> coast ERTS mosaics, were identified. Offshore patterns of sediment in areas such as the Santa Barbara Channel are traceable. These patterns extend offshore to heretofore unanticipated ranges as shown on the ERTS-1 imagery. Flying spot scanner enhancements of NASA tapes resulted in details of subtle and often invisible (to the eye) nearshore features. The suspended sediments off San Francisco and in Monterey Bay are emphasized in detail. These are areas of extremely changeable offshore sediment transport patterns. Computer generated contouring of radiance levels resulted in maps that can be used in determining surface and nearsurface suspended sediment distribution. Tentative calibrations of ERTS-1 spectral brightness against sediment load have been made using shipboard measurements. Information from the combined enhancement and interpretation techniques is applicable to operational coastal engineering programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMNH11A1342W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMNH11A1342W"><span id="translatedtitle">Comparison of Strong <span class="hlt">Currents</span> and Impacts on the <span class="hlt">California</span> (USA) Maritime Communities from the 2010 Chile and 2011 Japan Teletsunamis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilson, R. I.; Miller, K.; Davenport, C.; Nicolini, T.; Dengler, L.; Admire, A. R.; Synolakis, C.; Barberopoulou, A.; Borrero, J. C.; Lynett, P. J.; Jaffe, B. E.; Curtis, E.</p> <p>2011-12-01</p> <p>The February 27, 2010 Chile and March 11, 2011 Japan tsunamis caused dramatic loss of life and damage in the near-source region, and notable impacts in distant coastal regions like <span class="hlt">California</span>. Comprehensive post-tsunami surveys and the availability of hundreds of videos within harbors and marinas allow for detailed documentation of these two events by the State of <span class="hlt">California</span> Tsunami Program. Although neither event caused significant inundation of dry land in <span class="hlt">California</span> because peak arrival occurred during low tide, damage to docks, harbor infrastructure, and boats was noteworthy. The 2010 Chile tsunami caused approximately 3-million in damage to a dozen harbors, primarily in central and southern <span class="hlt">California</span> locations like Santa Cruz Harbor, Ventura Harbor and San Diego Bay. The 2011 Japan tsunami caused over 50-million in damage to more than two dozen harbors along the entire coast of <span class="hlt">California</span>, most extensively to harbors/marinas in Crescent City, Noyo River, and Santa Cruz. During both events, strong tsunami <span class="hlt">currents</span>, with some observed estimates greater than 15 knots, were generated at harbor entrances and along inside bends and narrows within harbors. Preliminary evaluations of harbor infrastructure and the interaction of boats indicate that drag along the base of large ships exacerbated the damage to docks to which the ships were tied. Evaluation of tsunami <span class="hlt">currents</span> and damage will help in the validation/calibration of numerical tsunami model <span class="hlt">currents</span> with the ultimate goal of developing tsunami <span class="hlt">current</span> hazard maps for harbors statewide. These hazard maps will improve emergency response and infrastructure planning within harbors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014DSRI...92...11F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014DSRI...92...11F"><span id="translatedtitle">Biogeography and phenology of satellite-measured phytoplankton seasonality in the <span class="hlt">California</span> <span class="hlt">current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Foukal, Nicholas P.; Thomas, Andrew C.</p> <p>2014-10-01</p> <p>Thirteen years (1998-2010) of satellite-measured chlorophyll a are used to establish spatial patterns in climatological phytoplankton biomass seasonality across the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS) and its interannual variability. Multivariate clustering based on the shape of the local climatological seasonal cycle divides the study area into four groups: two with spring-summer maxima representing the northern and southern coastal upwelling zones, one with a summer minimum offshore in mid-latitudes and a fourth with very weak seasonality in between. Multivariate clustering on the seasonal cycles from all 13 years produces the same four seasonal cycle types and provides a view of the interannual variability in seasonal biogeography. Over the study period these seasonal cycles generally appear in similar locations as the climatological clusters. However, considerable interannual variability in the geography of the seasonal cycles is evident across the CCS, the most spatially extensive of which are associated with the 1997-1999 El Nio-Southern Oscillation (ENSO) signal and the 2005 delayed spring transition off the Oregon and northern and central <span class="hlt">California</span> coasts. We quantify linear trends over the study period in the seasonal timing of the two seasonal cycles that represent the biologically productive coastal upwelling zones using four different metrics of phenology. In the northern upwelling region, the date of the spring maximum is delaying (1.34 days yr-1) and the central tendency of the summer elevated chlorophyll period is advancing (0.63 days yr-1). In the southern coastal upwelling region, both the initiation and cessation of the spring maximum are delaying (1.78 days yr-1 and 2.44 days yr-1, respectively) and the peak is increasing in duration over the study period. Connections between observed interannual shifts in phytoplankton seasonality and physical forcing, expressed as either basin-scale climate signals or local forcing, show phytoplankton seasonality in the CCS to be influenced by changes in the seasonality of the wind mixing power offshore, coastal upwelling in the near-shore regions and basin-scale signals such as ENSO across the study area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PrOce..84..242A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PrOce..84..242A"><span id="translatedtitle">Top-down and bottom-up factors affecting seabird population trends in the <span class="hlt">California</span> <span class="hlt">current</span> system (1985-2006)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ainley, David G.; David Hyrenbach, K.</p> <p>2010-03-01</p> <p>To characterize the environmental factors affecting seabird population trends in the central portion of the <span class="hlt">California</span> <span class="hlt">current</span> system (CCS), we analyzed standardized vessel-based surveys collected during the late spring (May-June) upwelling season over 22 yr (1985-2006). We tested the working hypothesis that population trends are related to species-specific foraging ecology, and predicted that temporal variation in population size should be most extreme in diving species with higher energy expenditure during foraging. We related variation in individual species abundance (number km -2) to seasonally lagged (late winter, early spring, late spring) and concurrent ocean conditions, and to long-term trends (using a proxy variable: year) during a multi-decadal period of major fluctuations in the El Niño-Southern oscillation (ENSO) and the Pacific decadal oscillation (PDO). We considered both remote (Multivariate ENSO Index, PDO) and local (coastal upwelling indices and sea-surface temperature) environmental variables as proxies for ocean productivity and prey availability. We also related seabird trends to those of potentially major trophic competitors, humpback ( Megaptera novaeangliae) and blue ( Balaenoptera musculus) whales, which increased in number 4-5-fold midway during our study. Cyclical oscillations in seabird abundance were apparent in the black-footed albatross ( Phoebastria nigripes), and decreasing trends were documented for ashy storm-petrel ( Oceanodroma homochroa), pigeon guillemot ( Cepphus columbus), rhinoceros auklet ( Cerorhinca monocerata), Cassin’s auklet ( Ptychoramphus aleuticus), and western gull ( Larus occidentalis); the sooty shearwater ( Puffinus griseus), exhibited a marked decline before signs of recovery at the end of the study period. The abundance of nine other focal species varied with ocean conditions, but without decadal or long-term trends. Six of these species have the largest global populations in the CCS, and four are highly energetic, diving foragers. Furthermore, three of the diving species trends were negatively correlated with the abundance of humpback whales in the study area, a direct competitor for the same prey. Therefore, on the basis of literature reviewed, we hypothesize that the seabirds were affected by the decreasing carrying capacity of the CCS, over-exploitation of some prey stocks and interference competition from the previously exploited, but now increasing, baleen whale populations. Overall, our study highlights the complexity of the ecological factors driving seabird population trends in the highly variable and rapidly changing CCS <span class="hlt">ecosystem</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DSRII.112...79P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DSRII.112...79P"><span id="translatedtitle">Covariability of zooplankton gradients with glider-detected density fronts in the Southern <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Powell, Jesse R.; Ohman, Mark D.</p> <p>2015-02-01</p> <p>Fronts represent sharp boundaries between water masses, but seasonal and interannual variation in their occurrence and effects on the distributions of pelagic organisms are poorly understood. This study reports results from six years of ocean front observations (2006-2011) along two transect lines across the Southern <span class="hlt">California</span> <span class="hlt">Current</span> System (SCCS) using autonomous Spray ocean gliders. During this time, 154 positive near-surface density fronts were identified within 124 completed transects consisting of nearly 23,000 vertical profiles. The incidence of surface density fronts showed distinct seasonality along line 80 off Pt. Conception, with fewer fronts occurring during winter months and more numerous fronts in the nearshore and during spring, summer and fall. On line 90, fronts were the least common nearshore and most frequent in a transitional region offshore. Horizontal density gradients in the surface layer (0-50 m) were significantly correlated with horizontal gradients in surface layer Chlorophyll-a (Chl-a) fluorescence, as well as with mean volume backscatter (MVBS) recorded by a 750 kHz acoustic Doppler profiler. Density fronts were not only zones of rapidly changing phytoplankton and zooplankton biomass concentrations, but also more likely to be zones of enhanced acoustic backscatter and Chl-a fluorescence than regions flanking the fronts. MVBS and Chl-a gradients were significantly correlated with gradients in other hydrographic variables such as temperature, salinity, and spiciness, and weakly with cross-track <span class="hlt">current</span> velocity, though density gradients remained the single best predictor of strong MVBS and fluorescence gradients. Large mobile predators foraging in the vicinity of such features could locate habitat with higher zooplankton biomass concentrations up to 85% of the time by traveling up local density gradients (i.e., toward rather than away from denser surface waters). We discuss implications of these results in the context of long-term trends in ocean fronts in the SCCS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=116500&keyword=floods&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=57506970&CFTOKEN=61056637','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=116500&keyword=floods&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=57506970&CFTOKEN=61056637"><span id="translatedtitle">MICROBIAL INDICATORS OF AQUATIC <span class="hlt">ECOSYSTEM</span> CHANGE: <span class="hlt">CURRENT</span> APPLICATIONS TO EUTROPHICATION STUDIES. (R828677C001)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p><p>Human encroachment on aquatic <span class="hlt">ecosystems</span> is increasing at an unprecedented rate. The impacts of human pollution and habitat alteration are most evident and of greatest concern at the microbial level, where a bulk of production and nutrient cycling takes place. Aquatic ecosyste...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010107999','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010107999"><span id="translatedtitle">Bio-Optical Measurement and Modeling of the <span class="hlt">California</span> <span class="hlt">Current</span> and Polar Oceans</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mitchell, B. Greg; Fargion, Giulietta S. (Technical Monitor)</p> <p>2001-01-01</p> <p>The principal goals of our research are to validate standard or experimental products through detailed bio-optical and biogeochemical measurements, and to combine ocean optical observations with advanced radiative transfer modeling to contribute to satellite vicarious radiometric calibration and advanced algorithm development. To achieve our goals requires continued efforts to execute complex field programs globally, as well as development of advanced ocean optical measurement protocols. We completed a comprehensive set of ocean optical observations in the <span class="hlt">California</span> <span class="hlt">Current</span>, Southern Ocean, Indian Ocean requiring a large commitment to instrument calibration, measurement protocols, data processing and data merger. We augmented separately funded projects of our own, as well as others, to acquire ill situ data sets we have collected on various global cruises supported by separate grants or contracts. In collaboration with major oceanographic ship-based observation programs funded by various agencies (CalCOFI, US JGOFS, NOAA AMLR, INDOEX and Japan/East Sea) our SIMBIOS effort has resulted in data from diverse bio-optical provinces. For these global deployments we generate a high-quality, methodologically consistent, data set encompassing a wide-range of oceanic conditions. Global data collected in recent years have been integrated with our on-going CalCOFI database and have been used to evaluate SeaWiFS algorithms and to carry out validation studies. The combined database we have assembled now comprises more than 700 stations and includes observations for the clearest oligotrophic waters, highly eutrophic blooms, red-tides and coastal case 2 conditions. The data has been used to validate water-leaving radiance estimated with SeaWiFS as well as bio-optical algorithms for chlorophyll pigments. The comprehensive data is utilized for development of experimental algorithms (e.g. high-low latitude pigment transition, phytoplankton absorption, and cDOM). During this period we completed 9 peer-reviewed publications in high quality journals, and presented aspects of our work at more than 10 scientific conferences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020016073&hterms=eutrophic+oceans&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Deutrophic%2Boceans','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020016073&hterms=eutrophic+oceans&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Deutrophic%2Boceans"><span id="translatedtitle">Bio-Optical Measurement and Modeling of the <span class="hlt">California</span> <span class="hlt">Current</span> and Polar Oceans. Chapter 13</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mitchell, B. Greg</p> <p>2001-01-01</p> <p>This Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) project contract supports in situ ocean optical observations in the <span class="hlt">California</span> <span class="hlt">Current</span>, Southern Ocean, Indian Ocean as well as merger of other in situ data sets we have collected on various global cruises supported by separate grants or contracts. The principal goals of our research are to validate standard or experimental products through detailed bio-optical and biogeochemical measurements, and to combine ocean optical observations with advanced radiative transfer modeling to contribute to satellite vicarious radiometric calibration and advanced algorithm development. In collaboration with major oceanographic ship-based observation programs funded by various agencies (CalCOFI, US JGOFS, NOAA AMLR, INDOEX and Japan/East Sea) our SIMBIOS effort has resulted in data from diverse bio-optical provinces. For these global deployments we generate a high-quality, methodologically consistent, data set encompassing a wide-range of oceanic conditions. Global data collected in recent years have been integrated with our on-going CalCOFI database and have been used to evaluate Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) algorithms and to carry out validation studies. The combined database we have assembled now comprises more than 700 stations and includes observations for the clearest oligotrophic waters, highly eutrophic blooms, red-tides and coastal case two conditions. The data has been used to validate water-leaving radiance estimated with SeaWiFS as well as bio optical algorithms for chlorophyll pigments. The comprehensive data is utilized for development of experimental algorithms (e.g., high-low latitude pigment transition, phytoplankton absorption, and cDOM).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/wri/1988/4027/report.pdf','USGSPUBS'); return false;" href="http://pubs.usgs.gov/wri/1988/4027/report.pdf"><span id="translatedtitle">Tides, and tidal and residual <span class="hlt">currents</span> in Suisun and San Pablo bays, <span class="hlt">California</span>; results of measurements, 1986</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gartner, J.W.; Yost, B.T.</p> <p>1988-01-01</p> <p><span class="hlt">Current</span> meter data collected at 11 stations and water level data collected at one station in Suisun and San Pablo Bays, <span class="hlt">California</span>, in 1986 are compiled in this report. <span class="hlt">Current</span>-meter measurements include <span class="hlt">current</span> speed and direction, and water temperature and salinity (computed from temperature and conductivity). For each of the 19 <span class="hlt">current</span>-meter records, data are presented in two forms. These are: (1) results of harmonic analysis; and (2) plots of tidal <span class="hlt">current</span> speed and direction versus time and plots of temperature and salinity versus time. Spatial distribution of the properties of tidal <span class="hlt">currents</span> are given in graphic form. In addition, Eulerian residual <span class="hlt">currents</span> have been compiled by using a vector-averaging technique. Water level data are presented in the form of a time-series plot and the results of harmonic analysis. (USGS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900042574&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2528sea%2Blevel%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900042574&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2528sea%2Blevel%2529"><span id="translatedtitle">Continuous assimilation of Geosat altimetric sea level observations into a numerical synoptic ocean model of the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>White, Warren B.; Tai, Chang-Kou; Holland, William R.</p> <p>1990-01-01</p> <p>The Geosat altimetric sea level observations for the period from January to December 1987 were continuously assimilated into a realistic wind-driven numerical synoptic ocean model of the <span class="hlt">California</span> <span class="hlt">Current</span> in order to evaluate the effectiveness of using a realistic synoptic ocean model for interpolating (dynamically) real altimetric sea level observations onto a regular grid. The accuracy of dynamical interpolation was tested by comparing the gridded sea level residuals to ones estimated from in situ observations (by expendable bathythermographs) collected in the <span class="hlt">California</span> <span class="hlt">Current</span> region during the same period. The comparison yielded nearly exact agreement at low frequency (i.e., semiannual cycle), but less agreement on month-to-month time scales of variability, possibly due to the unfiltered nature of the in situ estimates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EurSS..48..664R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EurSS..48..664R"><span id="translatedtitle"><span class="hlt">Current</span> stage of the restoration of Chernozems in rangeland <span class="hlt">ecosystems</span> of the steppe zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rusanov, A. M.</p> <p>2015-06-01</p> <p>The results of two rounds of soil and geobotanic surveys of rangeland <span class="hlt">ecosystems</span> in the steppe zone are presented. The same sites with southern chernozems (Calcic Chernozems) under steppe plant communities at different stages of pasture degradation were investigated at the end of the 1980s, when they suffered maximum anthropogenic loads, and in 2011-2013, after a long period of relative rest. In the 1980s, degradation of soil physical properties in rangeland <span class="hlt">ecosystems</span> under the impact of long-term unsustainable management was noted. At the same time, it was found that the major qualitative and quantitative properties of humus in the chernozems were preserved independently from the level of pasture degradation. The following period of moderate grazing pressure had a favorable effect on the soil properties. Owing to the good characteristics of the soil humus, the restoration of the physical properties of chernozems-including their structural state, water permeability, and bulk density-took place in a relatively short period. It is argued that the soil bulk density is a natural regulator of the species composition of steppe vegetation, because true grasses (Poaceae)-typical representatives of the steppe flora-have a fibrous root system requiring the soils with low density values. The improvement of the properties of chernozems is related to the development of secondary <span class="hlt">ecosystems</span> with a higher portion of grasses in place of damaged rangelands and to the increase in the area of nominal virgin phytocenoses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992JGR....9712535T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992JGR....9712535T"><span id="translatedtitle">Observations of the geostrophic <span class="hlt">current</span> and water mass characteristics off Point Sur, <span class="hlt">California</span>, from May 1988 through November 1989</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tisch, Timothy D.; Ramp, Steven R.; Collins, Curtis A.</p> <p>1992-08-01</p> <p>The Point Sur transect (POST) has been occupied 6-8 times per year since 1988 to resolve the flow in the <span class="hlt">California</span> <span class="hlt">Current</span> system at seasonal and interannual time scales. The POST extends offshore, normal to bottom topography, along 3620'N, to 12301.7'W where it doglegs southwest along the <span class="hlt">California</span> Cooperative Fisheries Investigation (CalCOFI) line 67. Hydrographic observations from seven cruises over 2 years have been used to study variations of alongshore geostrophic velocities and water mass characteristics within these time scales. The <span class="hlt">California</span> Undercurrent was a prominent feature in six of the seven sections analyzed and was very weak during a period of strong equatorward wind stress. The position of the undercurrent core varied from 12 to 42 km from shore while its strength varied from less than 5 cm s-1 to 35 cm s-1, with the maximum flow occurring in winter. The undercurrent (core) over the continental slope was found from 70 to 460 m depth throughout these seven cruises. The nature of the alongshore geostrophic velocities and the location and spatial extent of the <span class="hlt">California</span> Undercurrent appear strongly related to specific wind events, both local and remote. Remote wind forcing from the south was believed to cause anomalous, strong poleward flow throughout the entire water column above 1000 dbar during a period of local equatorward wind stress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B44C..08K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B44C..08K"><span id="translatedtitle">Quantifying radaition and energy balances at a heterogeneous oak savanna <span class="hlt">ecosystem</span> in <span class="hlt">California</span>: a three dimensional modeling appraoch</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kobayashi, H.; Baldocchi, D. D.; Ryu, Y.; Chen, Q.; Ma, S.; Osuna, J. L.; Ustin, S.</p> <p>2010-12-01</p> <p>Most land surface and <span class="hlt">ecosystem</span> models assume that a vegetated canopy can be abstracted as a turbid medium when they compute mass, energy, and carbon exchange. Since savanna <span class="hlt">ecosystems</span> are inherently complex and spatially heterogeneous, a turbid media models fail to simulate radiation environments at savanna <span class="hlt">ecosystems</span>. In this study, we describe a three dimensional radiation budget model (Forest Light Environmental Simulator, FLiES) coupled with a soil and canopy energy balance and canopy physiology model (CANOAK). The model was able to simulate spatial and diurnal patterns of radiation properties both shortwave and longwave radiation as well as latent and sensible heat, and tree canopy photosynthesis. Explicit consideration of woody elements (branches and stems) is crucial for realistic computation of radiation environments in savanna <span class="hlt">ecosystems</span> because of its nature of low LAI and a relatively high fraction of woody elements. We found that the heat storage term of woody elements could be non-negligible amount (12-17% of total net radiation). We found that all woodland components (tree leaves, understory grasses, woody materials, and the soil) cannot be negligible for modeling the radiation and energy balances as they all absorb a significant amount of the solar radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhDT.......178L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhDT.......178L"><span id="translatedtitle">The importance of a Mediterranean type <span class="hlt">ecosystem</span> in trace gas fluxes from the chaparral of Southern <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luo, Hongyan</p> <p></p> <p>Carbon flux measurements over a ca. 100-year old-growth chamise-dominated chaparral shrub <span class="hlt">ecosystem</span> using eddy covariance techniques were conducted from 1996 to 2003. Results indicate carbon sinks, from -96 to -155 g C m-2 yr-1, under normal climate conditions, but were a weak sink of -18 g C m-2 yr-1 to a strong source of 207 g C m-2yr-1 as a consequence of a severe drought. The annual sink strength of carbon averaged -52 g C m -2 yr-1, which is comparable to many other <span class="hlt">ecosystems</span> and indicates that, in contrast to previous thought, the old-growth chaparral shrub <span class="hlt">ecosystem</span> can be a significant sink of carbon and, therefore, an important component of the global carbon budget. In the comparison experiments, a ca. 100-year chaparral stand (96 to 102-year old) demonstrated a substantial cumulative carbon sink of -391 g C m-2, while a ca. 10-year old chaparral (5 to 11-year old) stand exhibited a moderate carbon source of 114 g C m -2 over the measurement period. This caused the rejection to our hypothesis that young stand would be more productive than the old stand. The cumulative ET at the old stand was 2657 mm, which was higher than the value of 1885 mm at the young stand confirming earlier assumptions of lower water use in young stands. NEE and ET difference between the young stand and the old stand was likely due to the significantly higher soil temperature and higher soil moisture at the young stand than at the old stand. Measurements over the ca. 100-year chaparral <span class="hlt">ecosystem</span> demonstrated that carbon uptake was largest in the growing season, but constrained in both the dry and winter seasons. The variability of water availability was the primary control on the intra and inter-annual variation of <span class="hlt">ecosystem</span> carbon and water exchange. Air temperature increase resulted in a linear increase in seasonal carbon fixation and water loss during daytime. Nighttime <span class="hlt">ecosystem</span> respiration increased as an exponential function with soil temperature in all seasons. <span class="hlt">Ecosystem</span> dark respiration rates were similar in all seasons. The maximum carbon uptake rate was far larger in the growing season than other seasons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGeo...10.4419I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGeo...10.4419I"><span id="translatedtitle">Air-sea exchange of CO2 at a Northern <span class="hlt">California</span> coastal site along the <span class="hlt">California</span> <span class="hlt">Current</span> upwelling system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ikawa, H.; Faloona, I.; Kochendorfer, J.; Paw U, K. T.; Oechel, W. C.</p> <p>2013-07-01</p> <p>It is not well understood whether coastal upwelling is a net CO2 source to the atmosphere or a net CO2 sink to the ocean due to high temporal variability of air-sea CO2 exchange (CO2 flux) in coastal upwelling zones. Upwelling transports heterotrophic, CO2 enriched water to the surface and releases CO2 to the atmosphere, whereas the presence of nutrient-rich water at the surface supports high primary production and atmospheric CO2 uptake. To quantify the effects of upwelling on CO2 flux, we measured CO2 flux at a coastal upwelling site off of Bodega Bay, <span class="hlt">California</span>, with the eddy covariance technique during the summer of 2007 and the fall of 2008, and the bulk method with partial pressure of CO2 of surface water (pCO2) data from November 2010 to July 2011. Variations in sea surface temperatures (SST) and alongshore wind velocity suggest that the measurement period in 2007 coincided with a typical early summer upwelling period and the measurement period in 2008 was during a typical fall relaxation period. A strong source of CO2 (~ 1.5 7 SD (standard deviation) g C m-2 day-1) from the ocean to the atmosphere during the upwelling period was concurrent with high salinity, low SST, and low chlorophyll density. In contrast, a weak source of CO2 flux (~ 0.2 3 SD g C m-2 day-1) was observed with low salinity, high SST and high chlorophyll density during the relaxation period. Similarly, the sink and source balance of CO2 flux was highly related to salinity and SST during the pCO2 measurement periods; high salinity and low SST corresponded to high pCO2, and vice versa. We estimated that the coastal area off Bodega Bay was likely an overall source of CO2 to the atmosphere based on the following conclusions: (1) the overall CO2 flux estimated from both eddy covariance and pCO2 measurements showed a source of CO2; (2) although the relaxation period during the 2008 measurements were favorable to CO2 uptake, CO2 flux during this period was still a slight source; (3) salinity and SST were found to be good predictors of the CO2 flux for both eddy covariance and pCO2 measurements, and 99% of the historical SST and salinity data available between 1988 and 2011 fell within the range of our observations in May-June 2007, August-September 2008 and November 2010-July~2011, which indicates that our data set was representative of the annual variations in the sea state. Based on the developed relationship between pCO2, SST and salinity, the study area between 1988 and 2011 was estimated to be an annual source of CO2 of ~ 35 mol C m-2 yr-1. The peak monthly CO2 flux of ~ 7 mol C m-2 month-1 accounted for almost 30% of the dissolved inorganic carbon in the surface mixed layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=201093','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=201093"><span id="translatedtitle">MULTILOCUS SIMPLE SEQUENCE REPEATS AND SINGLE NUCLEOTIDE POLYMORPHISM MARKERS FOR GENOTYPING AND ASSESSING GENETIC DIVERSITY OF XYLELLA FASTIDIOSA IN <span class="hlt">CALIFORNIA</span></span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>To develop effective disease management strategies, we need to understand population structure and genetic diversity of pathogens in agricultural <span class="hlt">ecosystems</span>. <span class="hlt">Current</span> information regarding population structure and genetic diversity of Xylella fastidiosa (Xf) in <span class="hlt">California</span> is insufficient to adequate...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSMNB32C..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSMNB32C..05L"><span id="translatedtitle">An Examination of References for <span class="hlt">Ecosystems</span> in a Watershed Context: Results of a Scientific Pulse in Redwood National and State Parks, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lisle, T. E.; Cummins, K.; Madej, M. A.</p> <p>2005-05-01</p> <p>A multidisciplinary pulse examined three pristine streams in old-growth redwood forests in northern <span class="hlt">California</span> to motivate discussions about the characteristics of reference sites for stream and riparian <span class="hlt">ecosystems</span>. We concluded that useful reference sites need not be pristine, but must be rich in data linking physical and biological processes and frame conditions in a watershed context. It is particularly important that the data constitute the present status of an historical array. Not requiring pristine conditions allows data-rich watersheds with a spectrum of conditions to be incorporated into a regional reference framework. Reference watersheds offer real-world examples of how <span class="hlt">ecosystems</span> function over time. Reference parameters taken from various locations in a region offer first-cut comparisons that can lead to deeper, more contextual analyses. Analytical references can reveal disturbance-related departures from conditions predicted with simple assumptions about some aspects of system behavior. All three reference types (reference sites, reference parameters, analytical references) have their strengths and weaknesses and can be used in combination to inform management decisions regarding these complex systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1174257','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1174257"><span id="translatedtitle">Using a Regional Cluster of AmeriFlux Sites in Central <span class="hlt">California</span> to Advance Our Knowledge on Decadal-Scale <span class="hlt">Ecosystem</span>-Atmosphere Carbon Dioxide Exchange</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Baldocchi, Dennis</p> <p>2015-03-24</p> <p>Continuous eddy convariance measurements of carbon dioxide, water vapor and heat were measured continuously between an oak savanna and an annual grassland in <span class="hlt">California</span> over a 4 year period. These systems serve as representative sites for biomes in Mediterranean climates and experience much seasonal and inter-annual variability in temperature and precipitation. These sites hence serve as natural laboratories for how whole <span class="hlt">ecosystem</span> will respond to warmer and drier conditions. The savanna proved to be a moderate sink of carbon, taking up about 150 gC m-2y-1 compared to the annual grassland, which tended to be carbon neutral and often a source during drier years. But this carbon sink by the savanna came at a cost. This <span class="hlt">ecosystem</span> used about 100 mm more water per year than the grassland. And because the savanna was darker and rougher its air temperature was about 0.5 C warmer. In addition to our flux measurements, we collected vast amounts of ancillary data to interpret the site and fluxes, making this site a key site for model validation and parameterization. Datasets consist of terrestrial and airborne lidar for determining canopy structure, ground penetrating radar data on root distribution, phenology cameras monitoring leaf area index and its seasonality, predawn water potential, soil moisture, stem diameter and physiological capacity of photosynthesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PrOce..83..369L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PrOce..83..369L"><span id="translatedtitle">Influence of a multiyear event of low salinity on the zooplankton from Mexican eco-regions of the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lavaniegos, Bertha E.</p> <p>2009-12-01</p> <p>Data are presented from the southern part of the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS) for the period 1997-2007, derived from the IMECOCAL monitoring program. Apart from El Niño 1997 to 1998, and La Niña 1998-1999 the strongest perturbation occurred in 2002 due to an intrusion of subarctic water affecting all the CCS. The response of zooplankton biomass to the strong cooling and freshening of the upper layer was an immediate drop followed by a progressive recovery between 2003 and 2007. Though the low salinity influence ended in 2006, the increased zooplankton trend continued, reinforced by increased upwelling activity beginning 2005 off north Baja <span class="hlt">California</span> region (30-32°N) and beginning 2006 off central Baja <span class="hlt">California</span> (24-30°N). Multiple regression analysis was done between regional variables and Upwelling Index (UI) and two basin-scale proxies: the North Pacific Gyre Oscillation (NPGO), and Pacific Decadal Oscillation (PDO). The significant influence of the NPGO on surface salinity, salinity stratification, zooplankton volume and secondary consumers (zooplankton carnivores) suggests a basin scale control on these variables more than local mechanisms. The signature of the NPGO was also evident in the base of the trophic web, but more related to the group of crustacean herbivores in the north eco-region, and the tunicates in central Baja <span class="hlt">California</span>. In this last region, the effect from NPGO on the zooplankton volume and tunicates was antagonist with UI indicative of similar importance of basin and local processes. However, when the time interval is limited to the post-subarctic intrusion (2003-2007) the significance of multiple regression models and physical variables was lost. Therefore, though data and bio-physical coupling analysis off Baja <span class="hlt">California</span> suggest a better relation with NPGO compared to PDO, it is still not sufficient to explain the magnitude of the perturbation observed in 2002.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PrOce..49..309S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PrOce..49..309S"><span id="translatedtitle">Climate change, reproductive performance and diet composition of marine birds in the southern <span class="hlt">California</span> <span class="hlt">Current</span> system, 1969 1997</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sydeman, William J.; Hester, Michelle M.; Thayer, Julie A.; Gress, Franklin; Martin, Paige; Buffa, Joelle</p> <p></p> <p>We studied the effects of low-frequency climate change on the reproductive performance of 11 species of marine bird in the southern <span class="hlt">California</span> <span class="hlt">Current</span> system, 1969-1997. Reproductive performance of Brown Pelican ( Pelecanus occidentalis) and Double-crested Cormorant ( Phalacrocrax auritus) in southern <span class="hlt">California</span> demonstrated an increase in the 1970s and early 1980s, attributable to recovery from organochlorine contamination (primarily DDE). Brandt's Cormorant ( Phalacrocorax penicillatus) in central <span class="hlt">California</span> was the only species to demonstrate a secular increase in performance through time, a pattern that remains unexplained. Ashy Storm-petrel ( Oceanodroma homochroa) and Pelagic Cormorant ( Phalacrocorax pelagicus) demonstrated curvilinear patterns of change, with decreasing reproductive performance in the past decade. All other species including Western Gull ( Larus occidentalis), Pigeon Guillemot ( Cepphus columba), Xantus's Murrelet ( Synthiloboramphus hypoleucus), Common Murre ( Uria aalge), Cassin's Auklet ( Ptychoramphus aleuticus) and Rhinoceros Auklet ( Cerorhinca monocerata) showed diminishing reproductive performance through time. Patterns of change for the murre and auklets were not significant, presumably because of a lack of reproductive variation for these species, which display a conservative breeding effort (i.e. single-egg clutches). Changes in the birds' abilities to provision young and maintain chick survival during May-July each year appeared most closely related to overall changes in reproductive performance. Dietary change indicated a decline in use of juvenile rockfish ( Sebastes spp.) by marine birds in central <span class="hlt">California</span>. There was also significant interannual variability in consumption of juvenile rockfish and the euphausiid Thysanoessa spinifera. Patterns of change in marine bird reproductive performance were generally concordant between southern and central <span class="hlt">California</span> after considering the period of recovery for Brown Pelican and Double-crested Cormorant. The decline in reproductive performance and changes in diet composition do not appear directly related to the polarity reversal of the Pacific Decadal Oscillation in 1976/1977. Instead, reproductive performance and dietary characteristics indicate substantial change in the late 1980s, suggesting another regime-shift at that time.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70020579','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70020579"><span id="translatedtitle">Changes in production and respiration during a spring phytoplankton bloom in San Francisco Bay, <span class="hlt">California</span>, USA: Implications for net <span class="hlt">ecosystem</span> metabolism</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Caffrey, J.M.; Cloern, J.E.; Grenz, C.</p> <p>1998-01-01</p> <p>We present results of an intensive sampling program designed to measure weekly changes in <span class="hlt">ecosystem</span> respiration (oxygen consumption in the water column and sediments) around the 1996 spring bloom in South San Francisco Bay, <span class="hlt">California</span>, USA. Measurements were made at a shallow site (2 m, where mean photic depth was 60% of the water column height) and a deep site (15 m, mean photic depth was only 20% of the water column). We also estimated phytoplankton primary production weekly at both sites to develop estimates of net oxygen flux as the sum of pelagic production (PP), pelagic respiration (PR) and benthic respiration (BR). Over the 14 wk period from February 5 to May 14, PP ranged from 2 to 210, PR from 9 to 289, and BR from 0.1 to 48 mmol O2 m-2 d-1, illustrating large variability of estuarine oxygen fluxes at the weekly time scale. Pelagic production exceeded total respiration at the shallow site, but not at the deep site, demonstrating that the shallow domains are net autotrophic but the deep domains are net heterotrophic, even during the period of the spring bloom. If we take into account the potential primary production by benthic microalgae, the estuary as a whole is net autotrophic during spring, net heterotrophic during the nonbloom seasons, and has a balanced net metabolism over a full annual period. The seasonal shift from net autotrophy to heterotrophy during the transition from spring to summer was accompanied by a large shift from dominance by pelagic respiration to dominance by benthic respiration. This suggests that changes in net <span class="hlt">ecosystem</span> metabolism can reflect changes in the pathways of energy flow in shallow coastal <span class="hlt">ecosystems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGeo...10.7395S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGeo...10.7395S"><span id="translatedtitle">Measurements of nitrite production in and around the primary nitrite maximum in the central <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Santoro, A. E.; Sakamoto, C. M.; Smith, J. M.; Plant, J. N.; Gehman, A. L.; Worden, A. Z.; Johnson, K. S.; Francis, C. A.; Casciotti, K. L.</p> <p>2013-11-01</p> <p>Nitrite (NO2-) is a substrate for both oxidative and reductive microbial metabolism. NO2- accumulates at the base of the euphotic zone in oxygenated, stratified open-ocean water columns, forming a feature known as the primary nitrite maximum (PNM). Potential pathways of NO2- production include the oxidation of ammonia (NH3) by ammonia-oxidizing bacteria and archaea as well as assimilatory nitrate (NO3-) reduction by phytoplankton and heterotrophic bacteria. Measurements of NH3 oxidation and NO3- reduction to NO2- were conducted at two stations in the central <span class="hlt">California</span> <span class="hlt">Current</span> in the eastern North Pacific to determine the relative contributions of these processes to NO2- production in the PNM. Sensitive (< 10 nmol L-1), precise measurements of [NH4+] and [NO2-] indicated a persistent NH4+ maximum overlying the PNM at every station, with concentrations as high as 1.5 ?mol L-1. Within and just below the PNM, NH3 oxidation was the dominant NO2- producing process, with rates of NH3 oxidation to NO2- of up to 31 nmol L-1 d-1, coinciding with high abundances of ammonia-oxidizing archaea. Though little NO2- production from NO3- was detected, potentially nitrate-reducing phytoplankton (photosynthetic picoeukaryotes, Synechococcus, and Prochlorococcus) were present at the depth of the PNM. Rates of NO2- production from NO3- were highest within the upper mixed layer (4.6 nmol L-1 d-1) but were either below detection limits or 10 times lower than NH3 oxidation rates around the PNM. One-dimensional modeling of water column NO2- production agreed with production determined from 15N bottle incubations within the PNM, but a modeled net biological sink for NO2- just below the PNM was not captured in the incubations. Residence time estimates of NO2- within the PNM ranged from 18 to 470 days at the mesotrophic station and was 40 days at the oligotrophic station. Our results suggest the PNM is a dynamic, rather than relict, feature with a source term dominated by ammonia oxidation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PrOce..79..352T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PrOce..79..352T"><span id="translatedtitle">Trophic modeling of the Northern Humboldt <span class="hlt">Current</span> <span class="hlt">Ecosystem</span>, Part I: Comparing trophic linkages under La Nia and El Nio conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tam, Jorge; Taylor, Marc H.; Blaskovic, Vernica; Espinoza, Pepe; Michael Balln, R.; Daz, Erich; Wosnitza-Mendo, Claudia; Argelles, Juan; Purca, Sara; Ayn, Patricia; Quipuzcoa, Luis; Gutirrez, Dimitri; Goya, Elisa; Ochoa, Noem; Wolff, Matthias</p> <p>2008-10-01</p> <p>The El Nio of 1997-98 was one of the strongest warming events of the past century; among many other effects, it impacted phytoplankton along the Peruvian coast by changing species composition and reducing biomass. While responses of the main fish resources to this natural perturbation are relatively well known, understanding the <span class="hlt">ecosystem</span> response as a whole requires an ecotrophic multispecies approach. In this work, we construct trophic models of the Northern Humboldt <span class="hlt">Current</span> <span class="hlt">Ecosystem</span> (NHCE) and compare the La Nia (LN) years in 1995-96 with the El Nio (EN) years in 1997-98. The model area extends from 4S-16S and to 60 nm from the coast. The model consists of 32 functional groups of organisms and differs from previous trophic models of the Peruvian system through: (i) division of plankton into size classes to account for EN-associated changes and feeding preferences of small pelagic fish, (ii) increased division of demersal groups and separation of life history stages of hake, (iii) inclusion of mesopelagic fish, and (iv) incorporation of the jumbo squid ( Dosidicus gigas), which became abundant following EN. Results show that EN reduced the size and organization of energy flows of the NHCE, but the overall functioning (proportion of energy flows used for respiration, consumption by predators, detritus and export) of the <span class="hlt">ecosystem</span> was maintained. The reduction of diatom biomass during EN forced omnivorous planktivorous fish to switch to a more zooplankton-dominated diet, raising their trophic level. Consequently, in the EN model the trophic level increased for several predatory groups (mackerel, other large pelagics, sea birds, pinnipeds) and for fishery catch. A high modeled biomass of macrozooplankton was needed to balance the consumption by planktivores, especially during EN condition when observed diatoms biomass diminished dramatically. Despite overall lower planktivorous fish catches, the higher primary production required-to-catch ratio implied a stronger ecological impact of the fishery and stresses the need for precautionary management of fisheries during and after EN. During EN energetic indicators such as the lower primary production/total biomass ratio suggest a more energetically efficient <span class="hlt">ecosystem</span>, while reduced network indicators such as the cycling index and relative ascendency indicate of a less organized state of the <span class="hlt">ecosystem</span>. Compared to previous trophic models of the NHCE we observed: (i) a shrinking of <span class="hlt">ecosystem</span> size in term of energy flows, (ii) slight changes in overall functioning (proportion of energy flows used for respiration, consumption by predators and detritus), and (iii) the use of alternate pathways leading to a higher ecological impact of the fishery for planktivorous fish.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED496306.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED496306.pdf"><span id="translatedtitle">Keeping <span class="hlt">California</span> School Districts Fiscally Healthy: <span class="hlt">Current</span> Practices and Ongoing Challenges. Report</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>EdSource, 2007</p> <p>2007-01-01</p> <p>When people talk about school district efficiency, their first thoughts are about financial management. Are districts balancing their budgets, paying bills on time, and maximizing their revenues? This report takes a closer look at financial management in <span class="hlt">California</span> school districts. The report is a summary of the 2006 research study, "School…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=259502','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=259502"><span id="translatedtitle">PACIFIC AREA-WIDE PROGRAM: <span class="hlt">CURRENT</span> STATUS OF THE <span class="hlt">CALIFORNIA</span> PERENNIAL NURSERY SECTOR</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>The perennial crop nursery industry supplies over 60% of the total fruit, nut, and rose plants sold in the USA. Although methyl bromide (MB) use has decreased in many <span class="hlt">California</span> industries due to the phaseout, perennial nursery producers largely continue to use MB under Critical Use Exemptions (CUE)...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70142976','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70142976"><span id="translatedtitle"><span class="hlt">Ecosystem</span> consequences of changing inputs of terrestrial dissolved organic matter to lakes: <span class="hlt">current</span> knowledge and future challenges</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Solomon, Christopher T.; Jones, Stuart E.; Weidel, Brian C.; Buffam, Ishi; Fork, Megan L; Karlsson, Jan; Larsen, Soren; Lennon, Jay T.; Read, Jordan S.; Sadro, Steven; Saros, Jasmine E.</p> <p>2015-01-01</p> <p>Lake <span class="hlt">ecosystems</span> and the services that they provide to people are profoundly influenced by dissolved organic matter derived from terrestrial plant tissues. These terrestrial dissolved organic matter (tDOM) inputs to lakes have changed substantially in recent decades, and will likely continue to change. In this paper, we first briefly review the substantial literature describing tDOM effects on lakes and ongoing changes in tDOM inputs. We then identify and provide examples of four major challenges which limit predictions about the implications of tDOM change for lakes, as follows: First, it is <span class="hlt">currently</span> difficult to forecast future tDOM inputs for particular lakes or lake regions. Second, tDOM influences <span class="hlt">ecosystems</span> via complex, interacting, physical-chemical-biological effects and our holistic understanding of those effects is still rudimentary. Third, non-linearities and thresholds in relationships between tDOM inputs and <span class="hlt">ecosystem</span> processes have not been well described. Fourth, much understanding of tDOM effects is built on comparative studies across space that may not capture likely responses through time. We conclude by identifying research approaches that may be important for overcoming those challenges in order to provide policy- and management-relevant predictions about the implications of changing tDOM inputs for lakes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25201299','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25201299"><span id="translatedtitle">Is tourism damaging <span class="hlt">ecosystems</span> in the Andes? <span class="hlt">Current</span> knowledge and an agenda for future research.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barros, Agustina; Monz, Christopher; Pickering, Catherine</p> <p>2015-03-01</p> <p>Despite the popularity of tourism and recreation in the Andes in South America and the regions conservation value, there is limited research on the ecological impacts of these types of anthropogenic use. Using a systematic quantitative literature review method, we found 47 recreation ecology studies from the Andes, 25 of which used an experimental design. Most of these were from the Southern Andes in Argentina (13 studies) or Chile (eight studies) with only four studies from the Northern Andes. These studies documented a range of impacts on vegetation, birds and mammals; including changes in plant species richness, composition and vegetation cover and the tolerance of wildlife of visitor use. There was little research on the impacts of visitors on soils and aquatic systems and for some ecoregions in the Andes. We identify research priorities across the region that will enhance management strategies to minimise visitor impacts in Andean <span class="hlt">ecosystems</span>. PMID:25201299</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950029611&hterms=pigment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpigment','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950029611&hterms=pigment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpigment"><span id="translatedtitle">Comparison of the seasonal and interannual variability of phytoplankton pigment concentrations in the Peru and <span class="hlt">California</span> <span class="hlt">Current</span> systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomas, A. C.; Huang, F.; Strub, P. T.; James, C.</p> <p>1994-01-01</p> <p>Monthly composite images from the global coastal zone color scanner (CZCS) data set are used to provide an initial illustration and comparison of seasonal and interannual variability of phytoplankton pigment concentration along the western coasts of South and North America in the Peru <span class="hlt">Current</span> system (PCS) and <span class="hlt">California</span> <span class="hlt">Current</span> system (CCS). The analysis utilizes the entire time series of available data (November 1978 to June 1986) to form a mean annual cycle and an index of interannual variability for a series of both latitudinal and cross-shelf regions within each <span class="hlt">current</span> system. Within 100 km of the coast, the strongest seasonal cycles in the CCS are in two regions, one between 34 deg and 45 deg N and the second between 24 deg and 29 deg N, each with maximum concentrations (greater than 3.0 mg m(exp-3)) in May-June. Weaker seasonal variability is present north of 45 deg N and in the Southern <span class="hlt">California</span> Bight region (32 deg N). Within the PCS, in the same 100-km-wide coastal region, highest (greater than 45 deg S) and lowest (less than 20 deg S) latitude regions have a similar seasonal cycle with maximum concentrations (greater than 1.5 mg m(exp -3)) during the austral spring, summer, and fall, matching that evident throughout the CCS. Between these regions, off northern and central Chile, the seasonal maximum occurs during July-August (austral winter), contrary to the influence of upwelling favorable winds. Within the CCS, the dominant feature of interannual variability in the 8-year time series is a strong negative concentration anomaly in 1983, an El Nino year. The relative value of this negative anomaly is strongest off central <span class="hlt">California</span> and is followed by an even stronger negative anomaly is strongest off central <span class="hlt">California</span> and is followed by an even stronger negative anomaly in 1984 off Baja, <span class="hlt">California</span>. In the PCS, strong negative anomalies during the 1982-1983 El Nino period are evident only off the Peruvian coast and are evident there only in the regions 100 km or more from the coast. Although negative anomalies associated with the El Nino were not present at higher latitudes (more than approximately 20 deg S) in the PCS, the extremely sparse sampling weakens our confidence in the results of the interannual analysis in this region. An upper estimate of the systematic winter bias remaining in the global CZCS data after reprocessing with the multiple scattering algorithm is given in the appendix.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PrOce..53..283B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PrOce..53..283B"><span id="translatedtitle">Patterns of co-variability among <span class="hlt">California</span> <span class="hlt">Current</span> chinook salmon, coho salmon, Dungeness crab, and physical oceanographic conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Botsford, L. W.; Lawrence, C. A.</p> <p></p> <p>One of the primary motivations for the GLOBEC NEP program was the apparent inverse relationship between the increase in salmon populations in the Gulf of Alaska since the mid-1970s and concurrent declines in salmon populations in the <span class="hlt">California</span> <span class="hlt">Current</span>. The increase in abundance of some salmon species in the Gulf of Alaska can be plausibly explained based on mechanisms involving changes in physical structure, biological productivity, and salmon survival. To assess concurrent changes in salmon populations in the <span class="hlt">California</span> <span class="hlt">Current</span> and their possible physical and biological bases we examined temporal and spatial patterns of co-variability between biological variables and physical descriptors along the coasts of Washington, Oregon and <span class="hlt">California</span>, from 1950 to 1990. The biological variables were catch records of coho salmon, chinook salmon and an ecologically related species, Dungeness crab. The physical variables were sea surface temperature, sea surface height (SSH) and the upwelling index (UWI). We found that while <span class="hlt">California</span> <span class="hlt">Current</span> coho salmon declined uniformly in the mid-1970s, consistent with the proposed inverse relationship, chinook salmon did not. All three species appear to be driven by the dominant mode of co-variability in the three physical variables, an indicator of warm/cool water conditions, but in different ways. In general, warm conditions have a negative effect on salmon at the age of ocean entry and spawning return, and Dungeness crab during the larval stage, while cool conditions have a positive effect. Differences in spatio-temporal variability between the two salmon species suggest they may respond to ocean conditions differently: coho salmon vary synchronously along the coast on annual time scales, while chinook salmon vary on slightly longer time scales in a specific spatial pattern. Dungeness crab vary on 10-year time scales, synchronously along the coast, except for the most southern areas (central <span class="hlt">California</span>) where populations collapsed in the late 1950s. The dominant, warm/cool mode of physical co-variability, which drives these populations regionally, is related to basin-scale indices; it appeared to follow these indices in the 1950s and 1975-1990, but differs from them1960-1975, in ways that may be biologically important.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/ofr20141041','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/ofr20141041"><span id="translatedtitle">Measurements of slope <span class="hlt">currents</span> and internal tides on the Continental Shelf and slope off Newport Beach, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Rosenberger, Kurt J.; Noble, Marlene A.; Norris, Benjamin</p> <p>2014-01-01</p> <p>An array of seven moorings housing <span class="hlt">current</span> meters and oceanographic sensors was deployed for 6 months at 5 sites on the Continental Shelf and slope off Newport Beach, <span class="hlt">California</span>, from July 2011 to January 2012. Full water-column profiles of <span class="hlt">currents</span> were acquired at all five sites, and a profile of water-column temperature was also acquired at two of the five sites for the duration of the deployment. In conjunction with this deployment, the Orange County Sanitation District deployed four bottom platforms with <span class="hlt">current</span> meters on the San Pedro Shelf, and these meters provided water-column profiles of <span class="hlt">currents</span>. The data from this program will provide the basis for an investigation of the interaction between the deep water flow over the slope and the internal tide on the Continental Shelf.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.B51A0190P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.B51A0190P"><span id="translatedtitle">Dissolved Organic Carbon and Nitrogen Leaching From Soil Formed in Grass, Oak and Pine <span class="hlt">Ecosystems</span> of <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pittiglio, S. L.; Zasoski, R. J.</p> <p>2005-12-01</p> <p>Dissolved organic matter (DOM) leaching from decomposing detritus accumulated above mineral soils is an important carbon (C) and nitrogen (N) flux that influences biogeochemical processes, C sequestration and the health of individual <span class="hlt">ecosystems</span>. This study compared the retention and transformation of DOM leached through soils formed under three contrasting vegetation types. In a laboratory study, columns of surface soil (10 cm diameter, 10 cm height) from either a grass, oak or pine site were leached with DOM derived from either grass, oak or pine litter. In the field, the laboratory study was replicated by burying columns of soil from the grass, oak and pine sites under the organic horizon at each sites. Leachates from in-situ field columns were collected biweekly beginning in January 2005. Samples were analyzed for volume, pH, total N, NO3-, NH4+, DON and DOC. In the laboratory leaching studies soils retained DOC derived from its native <span class="hlt">ecosystem</span> to a greater extent. These results suggest that the microbial community from each <span class="hlt">ecosystem</span> is adapted to consume the native DOC. No clear trends were found with DOC in the field study. Leachates from the field columns did show significantly lower levels of DON from pine soil columns at all sampling dates and sites. Similar results were found in the laboratory study with pine soil decreasing initial total N inputs from 32.9 to 3.6 mg kg-1. While all three sites contain kaolinite, vermiculite and chlorite, soil from the pine site also has high levels of iron oxides and gibbsite. The greater iron content likely contributes to higher DON retention since these minerals are know to have high affinities for the retention of DOM. The results from the field and laboratory experiments show that both soil minerals and the soil microbial communities play an important role in DOM retention in the subsoil.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10159978','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10159978"><span id="translatedtitle">Preliminary evaluation of the performance, water use, and <span class="hlt">current</span> application trends of evaporative coolers in <span class="hlt">California</span> climates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Huang, Y.J.; Hanford, J.W.; Wu, H.F.</p> <p>1992-09-01</p> <p>This paper describes the latest results of an ongoing analysis investigating the potential for evaporative cooling as an energy-efficient alternative to standard air-conditioning in <span class="hlt">California</span> residences. In particular, the study uses detailed numerical models of evaporative coolers linked with the DOE-2 building energy simulation program to study the issues of indoor comfort, energy and peak demand savings with and without supplemental air-conditioning and consumptive water use. In addition, limited surveys are used to assess the <span class="hlt">current</span> market availability of evaporative cooling in <span class="hlt">California</span>, typical contractor practices and costs, and general acceptance of the technology among engineers, contractors, and manufacturers. The results show that evaporative coolers can provide significant energy and peak demand savings in <span class="hlt">California</span> residences, but the impact of the increased indoor humidity on human comfort remains an unanswered question that requires further research and clarification. Evaluated against ASHRAE comfort standards developed primarily for air-conditioning both direct and two-stage evaporative coolers would not maintain comfort at peak cooling conditions due to excessive humidity. However, using bioclimatic charts that place human comfort at the 80% relative humidity line, the study suggests that direct evaporative coolers will work in mild coastal climates, while two-stage models should provide adequate comfort in Title 24 houses throughout <span class="hlt">California</span>, except in the Imperial Valley. The study also shows that evaporative coolers will increase household water consumption by less than 6% on an annual basis, and as much as 23% during peak cooling months, and that the increases in water cost are minimal compared to the electricity savings. Lastly, a survey of engineers and contractors revealed generally positive experiences with evaporative coolers, with operational cost savings, improved comfort, unproved air quality as the primary benefits in their use.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PrOce.106...16E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PrOce.106...16E"><span id="translatedtitle">Interannual variability in bottom-up processes in the upstream range of the <span class="hlt">California</span> <span class="hlt">Current</span> system: An isotopic approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El-Sabaawi, Rana W.; Trudel, Marc; Mackas, David L.; Dower, John F.; Mazumder, Asit</p> <p>2012-11-01</p> <p>The abundance and composition of zooplankton, fish and seabirds show dramatic interannual variability in temperate coastal regions. Understanding links between this variability and bottom-up processes is an important goal for biological oceanographers. Because zooplankton stable isotopes (?15N and ?13C) are potentially influenced by variability in phytoplankton nutrient utilization, primary production, and zooplankton trophic structure, they have the potential to elucidate links between bottom-up processes, food web structure, and abundance or species composition of higher trophic levels. Here we measure correlations between zooplankton stable isotopes and oceanographic variables in two time series from the west coast of Vancouver Island, upstream of the <span class="hlt">California</span> <span class="hlt">Current</span> upwelling system. We then relate interannual variability in zooplankton stable isotopes to interannual variability in zooplankton species composition. Zooplankton stable isotopes show striking patterns of seasonal, regional and interannual variability. A strong positive correlation between annual averages of zooplankton ?15N and sea-surface temperature is evident in both time series. Zooplankton ?15N is also negatively correlated with interannual anomalies of subarctic copepod biomass in both time series. We propose two different mechanisms to explain these correlations: variability in the strength and direction of horizontal advection, or local fluctuations nutrient availability. We conclude that they are most likely caused by local, temperature-driven fluctuations in nitrate concentrations and primary production. We show that the positive correlation between zooplankton ?15N and temperature is widespread, extending to regions outside of the <span class="hlt">California</span> <span class="hlt">Current</span> system. Our findings suggest that interannual variability in zooplankton composition is linked with bottom-up variability in nitrate availability and primary production in the upstream portion of the <span class="hlt">California</span> <span class="hlt">Current</span> system. Our results also highlight the potential of integrating biochemical parameters in zooplankton time series for elucidating links between bottom-up processes and the survival of higher trophic levels in the ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25517729','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25517729"><span id="translatedtitle">Does the <span class="hlt">current</span> fungicide risk assessment provide sufficient protection for key drivers in aquatic <span class="hlt">ecosystem</span> functioning?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zubrod, Jochen P; Englert, Dominic; Feckler, Alexander; Koksharova, Natalia; Konschak, Marco; Bundschuh, Rebecca; Schnetzer, Nadja; Englert, Katja; Schulz, Ralf; Bundschuh, Mirco</p> <p>2015-01-20</p> <p>The level of protection provided by the present environmental risk assessment (ERA) of fungicides in the European Union for fungi is unknown. Therefore, we assessed the structural and functional implications of five fungicides with different modes of action (azoxystrobin, carbendazim, cyprodinil, quinoxyfen, and tebuconazole) individually and in mixture on communities of aquatic hyphomycetes. This is a polyphyletic group of fungi containing key drivers in the breakdown of leaf litter, governing both microbial leaf decomposition and the palatability of leaves for leaf-shredding macroinvertebrates. All fungicides impaired leaf palatability to the leaf-shredder Gammarus fossarum and caused structural changes in fungal communities. In addition, all compounds except for quinoxyfen altered microbial leaf decomposition. Our results suggest that the European Union’s first-tier ERA provides sufficient protection for the tested fungicides, with the exception of tebuconazole and the mixture, while higher-tier ERA does not provide an adequate level of protection for fungicides in general. Therefore, our results show the need to incorporate aquatic fungi as well as their functions into ERA testing schemes to safeguard the integrity of aquatic <span class="hlt">ecosystems</span>. PMID:25517729</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1170076','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1170076"><span id="translatedtitle">Metagenomic analysis of microbial consortium from natural crude oil that seeps into the marine <span class="hlt">ecosystem</span> offshore Southern <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hawley, Erik R.; Piao, Hailan; Scott, Nicole M.; Malfatti, Stephanie; Pagani, Ioanna; Huntemann, Marcel; Chen, Amy; del Rio, Tijana G.; Foster, Brian; Copeland, A.; Jansson, Janet K.; Pati, Amrita; Gilbert, Jack A.; Tringe, Susannah G.; Lorenson, Thomas D.; Hess, Matthias</p> <p>2014-01-02</p> <p>Crude oils can be major contaminants of the marine <span class="hlt">ecosystem</span> and microorganisms play a significant role in the degradation of the main constituents of crude oil. To increase our understanding of the microbial hydrocarbon degradation process in the marine <span class="hlt">ecosystem</span>, we collected crude oil from an active seep area located in the Santa Barbara Channel (SBC) and generated a total of about 52 Gb of raw metagenomic sequence data. The assembled data comprised ~500 Mb, representing ~1.1 million genes derived primarily from chemolithoautotrophic bacteria. Members of Oceanospirillales, a bacterial order belonging to the Deltaproteobacteria, recruited less than 2% of the assembled genes within the SBC metagenome. In contrast, the microbial community associated with the oil plume that developed in the aftermath of the Deepwater Horizon (DWH) blowout in 2010, was dominated by Oceanospirillales, which comprised more than 60% of the metagenomic data generated from the DWH oil plume. This suggests that Oceanospirillales might play a less significant role in the microbially mediated hydrocarbon conversion within the SBC seep oil compared to the DWH plume oil. We hypothesize that this difference results from the SBC oil seep being mostly anaerobic, while the DWH oil plume is aerobic. Within the Archaea, the phylum Euryarchaeota, recruited more than 95% of the assembled archaeal sequences from the SBC oil seep metagenome, with more than 50% of the sequences assigned to members of the orders Methanomicrobiales and Methanosarcinales. These orders contain organisms capable of anaerobic methanogenesis and methane oxidation (AOM) and we hypothesize that these orders and their metabolic capabilities may be fundamental to the ecology of the SBC oil seep.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4149020','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4149020"><span id="translatedtitle">Metagenomic analysis of microbial consortium from natural crude oil that seeps into the marine <span class="hlt">ecosystem</span> offshore Southern <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hawley, Erik R.; Piao, Hailan; Scott, Nicole M.; Malfatti, Stephanie; Pagani, Ioanna; Huntemann, Marcel; Chen, Amy; Glavina del Rio, Tijana; Foster, Brian; Copeland, Alex; Jansson, Janet; Pati, Amrita; Tringe, Susannah; Gilbert, Jack A.; Lorenson, Thomas D.; Hess, Matthias</p> <p>2014-01-01</p> <p>Crude oils can be major contaminants of the marine <span class="hlt">ecosystem</span> and microorganisms play a significant role in the degradation of its main constituents. To increase our understanding of the microbial hydrocarbon degradation process in the marine <span class="hlt">ecosystem</span>, we collected crude oil from an active seep area located in the Santa Barbara Channel (SBC) and generated a total of about 52 Gb of raw metagenomic sequence data. The assembled data comprised ~500 Mb, representing ~1.1 million genes derived primarily from chemolithoautotrophic bacteria. Members of Oceanospirillales, a bacterial order belonging to the Deltaproteobacteria, recruited less than 2% of the assembled genes within the SBC metagenome. In contrast, the microbial community associated with the oil plume that developed in the aftermath of the Deepwater Horizon (DWH) blowout in 2010, was dominated by Oceanospirillales, which comprised more than 60% of the metagenomic data generated from the DWH oil plume. This suggests that Oceanospirillales might play a less significant role in the microbially mediated hydrocarbon conversion within the SBC seep oil compared to the DWH plume oil. We hypothesize that this difference results from the SBC oil seep being mostly anaerobic, while the DWH oil plume is aerobic. Within the Archaea, the phylum Euryarchaeota, recruited more than 95% of the assembled archaeal sequences from the SBC oil seep metagenome, with more than 50% of the sequences assigned to members of the orders Methanomicrobiales and Methanosarcinales. These orders contain organisms capable of anaerobic methanogenesis and methane oxidation (AOM) and we hypothesize that these orders – and their metabolic capabilities – may be fundamental to the ecology of the SBC oil seep. PMID:25197496</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRC..120.3913L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRC..120.3913L"><span id="translatedtitle">Modeling long-term change of planktonic <span class="hlt">ecosystems</span> in the northern South China Sea and the upstream Kuroshio <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Qian P.; Wang, Yanjun; Dong, Yuan; Gan, Jianping</p> <p>2015-06-01</p> <p>Field studies suggested that the biogeochemical settings and community structures are substantial different between the central Northern South China Sea (NSCS) and the upstream Kuroshio <span class="hlt">Current</span> (KC). In particular, the water column of KC is characterized by substantially lower nutrients and productivity but higher Trichodesmium abundance and nitrogen fixation compared to the NSCS. The mechanism driving the difference of the two marine <span class="hlt">ecosystems</span>, however, remains inadequately understood. Here, a one-dimensional biogeochemical model was developed to simulate the long-term variability of lower-trophic planktonic <span class="hlt">ecosystem</span> for two pelagic stations in the NSCS and the KC near the Luzon Strait. The physical model included the vertical mixing driven by air-sea interaction and the Ekman pumping induced by wind stress curl. The biological model was constructed by modifying a nitrogen-based NPZD model with the incorporation of phosphorus cycle and diazotroph nitrogen fixation. After validation by several field data sets, the model was used to study the impact of long-term physical forcing on <span class="hlt">ecosystem</span> variability in the two distinct stations. Our results suggested that nutrient transport above nitracline during summer was largely controlled by vertical turbulent mixing, while Ekman pumping was important for nutrient transport below the nitracline. Our results also indicated that diazotroph community structure and N2 fixation in the NSCS and the KC could be strongly influenced by physical processes through the impacts on vertical nutrient fluxes. The disadvantage of diazotroph in the NSCS in compared to the KC during the summer could be attributed to its high nitrate fluxes from subsurface leading to outcompete of diazotrophs by faster growing nondiazotroph phytoplankton.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/70305','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/70305"><span id="translatedtitle">Climate warming and the decline of zooplankton in the <span class="hlt">California</span> <span class="hlt">current</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roemmich, D.; McGowan, J.</p> <p>1995-03-03</p> <p>Since 1951, the biomass of macrozooplankton in waters off southern <span class="hlt">California</span> has decreased by 80 percent. During the same period, the surface layer warmed-by more than 1.5{degrees}C in some places-and the temperature differences across the thermocline increased. Increased stratification resulted in less lifting of the thermocline by wind-driven upwelling. A shallower source of upwelled waters provided less inorganic nutrient for new biological production and hence supported a smaller zooplankton population. Continued warming could lead to further decline of zooplankton. 10 refs., 5 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ocgy...55..871A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ocgy...55..871A"><span id="translatedtitle">Marine environmental monitoring in the shelf zone of the Black Sea: Assessment of the <span class="hlt">current</span> state of the pelagic <span class="hlt">ecosystem</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arashkevich, E. G.; Louppova, N. E.; Nikishina, A. B.; Pautova, L. A.; Chasovnikov, V. K.; Drits, A. V.; Podymov, O. I.; Romanova, N. D.; Stanichnaya, R. R.; Zatsepin, A. G.; Kuklev, S. B.; Flint, M. V.</p> <p>2015-11-01</p> <p>The state of the shelf pelagic <span class="hlt">ecosystem</span> has been assessed based on multidisciplinary monitoring performed in the northeastern Black Sea in 2005-2014. Seasonal and interannual variations in sea surface temperature (SST) and chlorophyll a (Chl-a) concentration have been analyzed along with the concentration of nutrients (silicate, nitrogen, and phosphate), biomass, and taxonomic compositions of phytoplankton, zooplankton, and gelatinous macroplankton. The linear trend shows an increase in the annual average SST by 0.9°C over the last decade. An increase in the winter SST is accompanied by a decrease in the concentration of silicates in spring ( p < 0.05) and an increase in summer SST, by a decrease in Chl-a concentration and biomass of diatoms in the period of summer to fall ( p < 0.05). A decrease in the phosphate concentration also has a negative effect on the development of diatoms ( p < 0.01). The decrease in diatom biomass caused a decrease in herbivorous zooplankton biomass in the second half of the year ( p = 0.05). Correlation analysis shows no significant dependence between the biomass of gelatinous top predators and mesozooplankton biomass. The assessed <span class="hlt">current</span> state of the shelf pelagic <span class="hlt">ecosystem</span> is regarded as stable; however, trends of a decrease in biomass and a change in the taxonomic composition of phytoplankton and zooplankton are observed during the last 2 years; the latter is likely to result from both direct and indirect effects of temperature increase in the upper sea layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A33F..06T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A33F..06T"><span id="translatedtitle">Decadal Changes in Ozone and Emissions in Central <span class="hlt">California</span> and <span class="hlt">Current</span> Issues</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanrikulu, S.; Beaver, S.; Soong, S.; Tran, C.; Cordova, J.; Palazoglu, A.</p> <p>2011-12-01</p> <p>The relationships among ozone, emissions, and meteorology are very complex in central <span class="hlt">California</span>, and must be well studied and understood in order to facilitate better air quality planning. Factors significantly impacting changes in emissions such as economic and population growth, and adopted emission controls make the matter even more complex. Here we review the history of ozone pollution in central <span class="hlt">California</span> since the 1970s to plan for the future. Since the 1970s, changes in emissions have been accompanied by likewise dramatic changes in region-to-region differences in air quality. We focus on the coastal San Francisco Bay Area (SFBA) and the inland San Joaquin Valley (SJV). In the 1970s, the SFBA population was approaching 5 million people while the considerably larger and more rural SJV population remained below 2 million. The SFBA population was mostly confined to coastal locations. Peak ozone levels occurred mostly around the population centers and especially over the Bay itself. Hourly average ozone levels routinely approached 160 ppb. These high ozone levels promoted regulations under which SFBA emissions were continuously reduced through the present. By the 1990s, SFBA emissions had been reduced considerably despite the region's population growing to around 6 million. Relative to the 1970s, in 1990s the SFBA had lower peak ozone levels that were shifted to inland locations where much of the population growth was occurring. The SFBA still exceeded the federal 1-hour standard. A rapidly changing economic landscape in the 1970s promoted vast changes in the central <span class="hlt">California</span> population distribution. In the SJV, the OPEC oil crisis promoted significant development of petroleum resources. Meanwhile, family farms were quickly being replaced with commercial-scale farming operations. The SJV population rapidly expanded to around 3 million people by the early 1990s. During this time, SJV emissions increased considerably, largely from increases in mobile source activities. The previously sparsely populated SJV had quickly developed an even more severe ozone problem than previous years. From 1990 to 2010, the SFBA population expanded to inland locations and then even further into the sheltered SJV. SFBA emissions for ROG and NOx were decreased around 40% and 15%, respectively during this period. High ozone levels became rather infrequent for coastal SFBA locations. During the same period, the SJV population continued to expand rapidly while emissions decreased, especially for ROG. Peak ozone levels remained around 100 ppb and shifted to locations downwind of Fresno and Bakersfield. Central <span class="hlt">California</span> has experienced perhaps the most dramatic population growth and shifts in the United States during the contemporary economic era. These changes in population have led to some of the most difficult air quality management problems faced by regulators in the United States. Lessons learned from central <span class="hlt">California</span> highlight the potential benefits of acting early and also the necessity for a long-term, flexible approach using sustained regulations to accompany population changes.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008QSRv...27.2530K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008QSRv...27.2530K"><span id="translatedtitle">Wildfire and abrupt <span class="hlt">ecosystem</span> disruption on <span class="hlt">California</span>'s Northern Channel Islands at the llerd-Younger Dryas boundary (13.0-12.9 ka)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kennett, D. J.; Kennett, J. P.; West, G. J.; Erlandson, J. M.; Johnson, J. R.; Hendy, I. L.; West, A.; Culleton, B. J.; Jones, T. L.; Stafford, Thomas W., Jr.</p> <p>2008-12-01</p> <p>Sedimentary records from <span class="hlt">California</span>'s Northern Channel Islands and the adjacent Santa Barbara Basin (SBB) indicate intense regional biomass burning (wildfire) at the llerd-Younger Dryas boundary (13.0-12.9 ka) (All age ranges in this paper are expressed in thousands of calendar years before present [ka]. Radiocarbon ages will be identified and clearly marked " 14C years".). Multiproxy records in SBB Ocean Drilling Project (ODP) Site 893 indicate that these wildfires coincided with the onset of regional cooling and an abrupt vegetational shift from closed montane forest to more open habitats. Abrupt <span class="hlt">ecosystem</span> disruption is evident on the Northern Channel Islands at the llerd-Younger Dryas boundary with the onset of biomass burning and resulting mass sediment wasting of the landscape. These wildfires coincide with the extinction of Mammuthus exilis [pygmy mammoth]. The earliest evidence for human presence on these islands at 13.1-12.9 ka (11,000-10,900 14C years) is followed by an apparent 600-800 year gap in the archaeological record, which is followed by indications of a larger-scale colonization after 12.2 ka. Although a number of processes could have contributed to a post 18 ka decline in M. exilis populations (e.g., reduction of habitat due to sea-level rise and human exploitation of limited insular populations), we argue that the ultimate demise of M. exilis was more likely a result of continental scale <span class="hlt">ecosystem</span> disruption that registered across North America at the onset of the Younger Dryas cooling episode, contemporaneous with the extinction of other megafaunal taxa. Evidence for <span class="hlt">ecosystem</span> disruption at 13-12.9 ka on these offshore islands is consistent with the Younger Dryas boundary cosmic impact hypothesis [Firestone, R.B., West, A., Kennett, J.P., Becker, L., Bunch, T.E., Revay, Z.S., Schultz, P.H., Belgya, T., Kennett, D.J., Erlandson, J.M., Dickenson, O.J., Goodyear, A.A., Harris, R.S., Howard, G.A., Kloosterman, J.B., Lechler, P., Mayewski, P.A., Montgomery, J., Poreda, R., Darrah, T., Que Hee, S.S., Smith, A.R., Stich, A., Topping, W., Wittke, J.H. Wolbach, W.S., 2007. Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and Younger Dryas cooling. Proceedings of the National Academy of Sciences 104, 16016-16021.].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/wri/1992/4064/report.pdf','USGSPUBS'); return false;" href="http://pubs.usgs.gov/wri/1992/4064/report.pdf"><span id="translatedtitle">Tidal and residual <span class="hlt">currents</span> measured by an acoustic doppler <span class="hlt">current</span> profiler at the west end of Carquinez Strait, San Francisco Bay, <span class="hlt">California</span>, March to November 1988</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Burau, J.R.; Simpson, M.R.; Cheng, R.T.</p> <p>1993-01-01</p> <p>Water-velocity profiles were collected at the west end of Carquinez Strait, San Francisco Bay, <span class="hlt">California</span>, from March to November 1988, using an acoustic Doppler <span class="hlt">current</span> profiler (ADCP). These data are a series of 10-minute-averaged water velocities collected at 1-meter vertical intervals (bins) in the 16.8-meter water column, beginning 2.1 meters above the estuary bed. To examine the vertical structure of the horizontal water velocities, the data are separated into individual time-series by bin and then used for time-series plots, harmonic analysis, and for input to digital filters. Three-dimensional graphic renditions of the filtered data are also used in the analysis. Harmonic analysis of the time-series data from each bin indicates that the dominant (12.42 hour or M2) partial tidal <span class="hlt">currents</span> reverse direction near the bottom, on average, 20 minutes sooner than M2 partial tidal <span class="hlt">currents</span> near the surface. Residual (nontidal) <span class="hlt">currents</span> derived from the filtered data indicate that <span class="hlt">currents</span> near the bottom are pre- dominantly up-estuary during the neap tides and down-estuary during the more energetic spring tides.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.C42A1011M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.C42A1011M"><span id="translatedtitle">Soil nitrogen dynamics during seasonal transitions: N retention and loss in <span class="hlt">ecosystems</span> of the Sierra Nevada, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miller, A. E.; Sickman, J. O.; Schimel, J. P.; Melack, J. M.; Meixner, T.</p> <p>2003-12-01</p> <p>The maintenance of nitrogen (N) limitation in many terrestrial <span class="hlt">ecosystems</span> may be mediated by N losses that occur during seasonal transitions. In the southern Sierra Nevada, short-duration nitrate pulses associated with spring snowmelt in the alpine, and with fall rains at lower elevations, may account for greater than 90% of annual DIN export. To evaluate the role of microbial processes in mediating such losses of N, we examined overwinter variation in soil N dynamics at a high (2800 m) and low (750 m) elevation site. The fall transition marked a period of intense nitrifier activity at both sites: field incubations showed five-fold to 30-fold increases in soil NO3- pools with the onset of fall freeze-thaw and rewetting events, followed by 60%-75% decreases in total soil inorganic N and net N mineralization rates. Nitrogen held in microbial biomass decreased significantly at the alpine site but recovered to growing-season levels under snowpack, indicating biotic sequestration of N. With the onset of spring snowmelt, microbial biomass again decreased, producing an increase in soil inorganic N concentrations and a shift from net N2O consumption to production. These results, paired with results of laboratory incubations, indicate that physical disturbances incurred during seasonal transitions may enhance nitrification and gaseous losses from soil, and that large fluctuations in microbial biomass may regulate N production and export in these systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880067901&hterms=Offshore+Power+Systems&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DOffshore%2BPower%2BSystems','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880067901&hterms=Offshore+Power+Systems&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DOffshore%2BPower%2BSystems"><span id="translatedtitle">Variability of pigment biomass in the <span class="hlt">California</span> <span class="hlt">Current</span> system as determined by satellite imagery. I - Spatial variability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, Raymond C.; Zhang, Xueyun; Michaelsen, Joel</p> <p>1988-01-01</p> <p>Spatial variability of chlorophyll in the <span class="hlt">California</span> <span class="hlt">Current</span> system was analyzed using Coastal Zone Color Scanner (CZCS) imagery. A total of 48 images were analyzed to produce seasonal averages and variances, gradients, and power spectra. Roughly one third to one half of the variance in pigment biomass can be explained by consistent, large-scale gradients. In general, biomass is higher in the north and in nearshore areas. Nearshore areas also have proportionally more small-scale variability than the areas offshore. Slopes of the power spectra for nearshore areas are about -2.2 (for spatial scales of 10-100 km), while slopes for offshore areas are about -3. In addition, the power spectra show evidence of a change in slope at about 10 km, with slopes of about -1 for shorter-length scales. This may indicate that biological processes dominate the smaller scales, while mesoscale eddies and geostrophic <span class="hlt">currents</span> dominate the larger scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70019505','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70019505"><span id="translatedtitle">Recovery strategies for the <span class="hlt">California</span> clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine <span class="hlt">ecosystem</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Foin, T.C.; Garcia, E.J.; Gill, R.E.; Culberson, S.D.; Collins, J.N.</p> <p>1997-01-01</p> <p>The <span class="hlt">California</span> clapper rail (Rallus longirostris obsoletus), a Federal- and State-listed endangered marsh bird, has a geographic range restricted to one of the most heavily-urbanized estuaries in the world. The rail population has long been in a state of decline, although the exact contribution of each of the many contributing causes remains unclear. The rail is one of the key targets of emerging plans to conserve and restore tidal marshlands. Reduction of tidal marsh habitat, estimated at 85-95%, has been the major historical cause of rail decline. Increased predation intensity may be the more important present problem, because habitat fragmentation and alteration coupled with the invasion of the red fox have made the remaining populations more vulnerable to predators. Population viability analysis shows that adult survivorship is the key demographic variable; reversals in population fate occur over a narrow range of ecologically realistic values. Analysis of habitat requirements and population dynamics of the clapper rail in the San Francisco Estuary shows that decreased within-marsh habitat quality, particularly reduction of tidal flows and alteration of drainage, is an important barrier to population recovery. Management and restoration activities should emphasize the development of well-channelized high tidal marsh, because this is the key requirement of rail habitat. Developing effective restoration programs depends upon having information that field research will not provide. The effect of spatial pattern of reserves requires accurate estimation of the effects of predation and inter-marsh movement, both of which are practically impossible to measure adequately. It will be necessary to develop and use simulation models that can be applied to geographic data to accomplish this task.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/ofr20131133','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/ofr20131133"><span id="translatedtitle">Salton Sea <span class="hlt">ecosystem</span> monitoring and assessment plan</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Case(compiler), H. L., III; Boles, Jerry; Delgado, Arturo; Nguyen, Thang; Osugi, Doug; Barnum, Douglas A.; Decker, Drew; Steinberg, Steven; Steinberg, Sheila; Keene, Charles; White, Kristina; Lupo, Tom; Gen, Sheldon; Baerenklau, Ken A.</p> <p>2013-01-01</p> <p>The Salton Sea, <span class="hlt">Californias</span> largest lake, provides essential habitat for several fish and wildlife species and is an important cultural and recreational resource. It has no outlet, and dissolved salts contained in the inflows concentrate in the Salton Sea through evaporation. The salinity of the Salton Sea, which is <span class="hlt">currently</span> nearly one and a half times the salinity of ocean water, has been increasing as a result of evaporative processes and low freshwater inputs. Further reductions in inflows from water conservation, recycling, and transfers will lower the level of the Salton Sea and accelerate the rate of salinity increases, reduce the suitability of fish and wildlife habitat, and affect air quality by exposing lakebed playa that could generate dust. Legislation enacted in 2003 to implement the Quantification Settlement Agreement (QSA) stated the Legislatures intent for the State of <span class="hlt">California</span> to undertake the restoration of the Salton Sea <span class="hlt">ecosystem</span>. As required by the legislation, the <span class="hlt">California</span> Resources Agency (now <span class="hlt">California</span> Natural Resources Agency) produced the Salton Sea <span class="hlt">Ecosystem</span> Restoration Study and final Programmatic Environmental Impact Report (PEIR; <span class="hlt">California</span> Resources Agency, 2007) with the stated purpose to develop a preferred alternative by exploring alternative ways to restore important ecological functions of the Salton Sea that have existed for about 100 years. A decision regarding a preferred alternative <span class="hlt">currently</span> resides with the <span class="hlt">California</span> State Legislature (Legislature), which has yet to take action. As part of efforts to identify an <span class="hlt">ecosystem</span> restoration program for the Salton Sea, and in anticipation of direction from the Legislature, the <span class="hlt">California</span> Department of Water Resources (DWR), <span class="hlt">California</span> Department of Fish and Wildlife (CDFW), U.S. Bureau of Reclamation (Reclamation), and U.S. Geological Survey (USGS) established a team to develop a monitoring and assessment plan (MAP). This plan is the product of that effort. The goal of the MAP is to provide a guide for data collection, analysis, management, and reporting to inform management actions for the Salton Sea <span class="hlt">ecosystem</span>. Monitoring activities are directed at species and habitats that could be affected by or drive future restoration activities. The MAP is not intended to be a prescriptive document. Rather, it is envisioned to be a flexible, program-level guide that articulates high-level goals and objectives, and establishes broad sideboards within which future project-level investigations and studies will be evaluated and authorized. As such, the MAP, by design, does not, for example, include detailed protocols describing how investigations will be implemented. It is anticipated that detailed study proposals will be prepared as part of an implementation plan that will include such things as specific sampling objectives, sampling schemes, and statistical and spatial limits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70022617','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70022617"><span id="translatedtitle">Subtidal <span class="hlt">currents</span> over the central <span class="hlt">California</span> slope: Evidence for offshore veering of the undercurrent and for direct, wind-driven slope <span class="hlt">currents</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Noble, M.A.; Ramp, S.R.</p> <p>2000-01-01</p> <p>In February 1991, an array of six <span class="hlt">current</span>-meter moorings was deployed for one year across the central <span class="hlt">California</span> outer shelf and slope. The main line of the array extended 30 km offshore of the shelf break, out to water depths of 1400 m. A more sparsely-instrumented line, displaced 30 km to the northwest, extended 14 km offshore. Though shorter, the northern line spanned similar water depths because the gradient of the topography steepened in the northern region. A poleward flow pattern, typical of the <span class="hlt">California</span> undercurrent, was seen across both lines in the array over most of the year. The poleward flow was surface intensified. In general, the portion of the undercurrent that crossed the southern line had larger amplitudes and penetrated more deeply into the water column than the portion that crossed the northern line. Transport over the year ranged from 0 to 2.5 Sverdrups (Sv) poleward across the southern line; 0 to 1 Sv poleward across the northern line. We suggest the difference in transport was caused by topographic constraints, which tended to force the poleward flow offshore of the northern measurement sites. The slope of the topography steepened too abruptly to allow the poleward flow to follow isobaths when <span class="hlt">currents</span> were strong. When <span class="hlt">current</span> velocities lessened, a more coherent flow pattern was seen across both lines in the array. In general, the poleward flow patterns in the undercurrent were not affected by local winds or by the local alongshore pressure gradient. Nor was a strong seasonal pattern evident. Rather unexpectedly, a small but statistically significant fraction of the <span class="hlt">current</span> variance over the mid- and outer slope was driven by the surface wind stress. An alongshelf wind stress caused <span class="hlt">currents</span> to flow along the slope, parallel to the wind field, down to depths of 400 m below the surface and out to distances of 2 Rossby radii past the shelf break. The transfer functions were weak, 3-4 cm/s per dyn cm-2, but comparable to wind-driven <span class="hlt">current</span> amplitudes of 4-6 cm/s per unit wind stress over the middle shelf. Equatorward, alongshelf winds also caused water from 200-300 m over the slope to upwell onto the shelf as the surface water moved offshore.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BGD....1214833Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGD....1214833Y"><span id="translatedtitle">How past fire disturbances have contributed to the <span class="hlt">current</span> carbon balance of boreal <span class="hlt">ecosystems</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yue, C.; Ciais, P.; Zhu, D.; Wang, T.; Peng, S. S.; Piao, S. L.</p> <p>2015-09-01</p> <p>Boreal fires have immediate effects on regional carbon budgets by emitting CO2 into the atmosphere at the time of burning, but also have legacy effects by initiating a long-term carbon sink during post-fire vegetation recovery. Quantifying these different effects on the <span class="hlt">current</span>-day pan-boreal (44-84 N) carbon balance and relative contributions of legacy sinks by past fires is important for understanding and predicting the carbon dynamics in this region. Here we used the global dynamic vegetation model ORCHIDEE-SPITFIRE to attribute the contributions by fires in different decades of 1850-2009 to the carbon balance of 2000-2009, taking into account the atmospheric CO2 change and climate change since 1850. The fire module of ORCHIDEE-SPITFIRE was turned off in each decade sequentially, and turned on before and after, to model the legacy carbon trajectory by fires in each past decade. We found that, unsurprisingly, fires that occured in 2000-2009 are a carbon source (-0.17 Pg C yr-1) for the 2000s-decade carbon balance, whereas fires in all decades before 2000 contribute carbon sinks with a collective contribution of 0.23 Pg C yr-1. This leaves a net fire sink effect of 0.06 Pg C yr-1, or 6.3 % of the simulated regional carbon sink (0.95 Pg C yr-1). Further, fires with an age of 10-40 years (i.e. those occurred during 1960-1999) contribute more than half of the total sink effect of fires. The small net sink effect of fires indicates that <span class="hlt">current</span>-day fire emissions are roughly in balance with legacy sinks. The future role of fires in the regional carbon balance remains uncertain and will depend on whether changes in fires and associated carbon emissions will exceed the enhanced sink effects of previous fires, both being strongly affected by global change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880067902&hterms=pigment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dpigment','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880067902&hterms=pigment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dpigment"><span id="translatedtitle">Variability of pigment biomass in the <span class="hlt">California</span> <span class="hlt">Current</span> system as determined by satellite imagery. II - Temporal variability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Michaelsen, Joel; Zhang, Xueyun; Smith, Raymond C.</p> <p>1988-01-01</p> <p>Characteristics of temporal variability in the <span class="hlt">California</span> <span class="hlt">Current</span> system are analyzed using a 30-month time series of CZCS imagery. About 20-25 percent of the variance is produced by a periodic annual cycle with peak values in winter. Analysis of ship-based chlorophyll measurements indicates that the winter peak is only characteristic of the upper portion of the euphotic zone and that total water column chlorophyll peaks during the spring upwelling season. Satellite studies of intraannual variability are modulated by strong 5- to 6-day oscillation in the availability of usable imagery, resulting from a combination of satellite orbital dynamics, which produces images of the study area roughly 4 out of every 6 days, and an oscillation in cloud cover, which controls the availability of clear imagery. The cloud cover oscillation, which is also present in coastal winds, undoubtedly affects the ocean surface and biases the data obtained by satellites. Analysis of data using a 5-day time step indicates that the predominant mode of nonseasonal variability is characterized by in-phase fluctuations throughout the southern and central <span class="hlt">California</span> coastal region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMS...146...50E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMS...146...50E"><span id="translatedtitle">Changes in forage fish community indicated by the diet of the Brandt's cormorant (Phalacrocorax penicillatus) in the central <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elliott, Meredith L.; Bradley, Russell W.; Robinette, Dan P.; Jahncke, Jaime</p> <p>2015-06-01</p> <p>The population, productivity and diet of two Brandt's cormorant (Phalacrocorax penicillatus) colonies located in the central <span class="hlt">California</span> <span class="hlt">Current</span> were compared. The offshore colony on Southeast Farallon Island has experienced a declining population over time and anomalously low productivity in recent years. The nearshore colony near Point Arguello has been increasing and its productivity has remained stable. The diets of cormorants at the two colonies elucidated by analysis of regurgitated pellets, while different, have shown similar decreases in the consumption of northern anchovy (Engraulis mordax) since 2008, followed by increased consumption of rockfish (Sebastes spp.) and flatfish (order Pleuronectiformes). By using the diet results from another seabird nesting in central <span class="hlt">California</span>, the rhinoceros auklet (Cerorhinca monocerata), and one from which whole fish can be obtained, we found that the rockfish species assemblage has changed with offshore rockfish species decreasing while nearshore ones have increased. This change in the rockfish species has negatively impacted Brandt's cormorants at the offshore colony by forcing them to make longer foraging trips to meet energy needs of themselves and their chicks; this has led to low breeding success and a declining population at this site. On the other hand, the nearshore colony has abundant nearby food resources, and it has prospered. These results underscore the value of using seabird data from multiple colonies to better understand changes occurring in the marine environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.9309B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.9309B"><span id="translatedtitle">Landscape anthropogenic disturbance in the Mediterranean <span class="hlt">ecosystem</span>: is the <span class="hlt">current</span> landscape sustainable?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Biondi, Guido; D'Andrea, Mirko; Fiorucci, Paolo; Franciosi, Chiara; Lima, Marco</p> <p>2013-04-01</p> <p>Mediterranean landscape during the last centuries has been subject to strong anthropogenic disturbances who shifted natural vegetation cover in a cultural landscape. Most of the natural forest were destroyed in order to allow cultivation and grazing activities. In the last century, fast growing conifer plantations were introduced in order to increase timber production replacing slow growing natural forests. In addition, after the Second World War most of the grazing areas were changed in unmanaged mediterranean conifer forest frequently spread by fires. In the last decades radical socio economic changes lead to a dramatic abandonment of the cultural landscape. One of the most relevant result of these human disturbances, and in particular the replacement of deciduous forests with coniferous forests, has been the increasing in the number of forest fires, mainly human caused. The presence of conifers and shrubs, more prone to fire, triggered a feedback mechanism that makes difficult to return to the stage of potential vegetation causing huge economic, social and environmental damages. The aim of this work is to investigate the sustainability of the <span class="hlt">current</span> landscape. A future landscape scenario has been simulated considering the natural succession in absence of human intervention assuming the <span class="hlt">current</span> fire regime will be unaltered. To this end, a new model has been defined, implementing an ecological succession model coupled with a simply Forest Fire Model. The ecological succession model simulates the vegetation dynamics using a rule-based approach discrete in space and time. In this model Plant Functional Types (PFTs) are used to describe the landscape. Wildfires are randomly ignited on the landscape, and their propagation is simulated using a stochastic cellular automata model. The results show that the success of the natural succession toward a potential vegetation cover is prevented by the frequency of fire spreading. The actual landscape is then unsustainable because of the high cost of fire fighting activities. The right path to success consists in development of suitable land use planning and forest management to mitigate the consequences of past anthropogenic disturbances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED564026.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED564026.pdf"><span id="translatedtitle">Examining <span class="hlt">Current</span> and Proposed Home Language Surveys in <span class="hlt">California</span> in Relation to Initial English Language Proficiency Assessment Results: An Exploratory Study</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Haas, Eric; Tran, Loan; Linquanti, Robert; Bailey, Alison</p> <p>2015-01-01</p> <p>The purpose of this exploratory study was to examine the extent to which a proposed home language survey in <span class="hlt">California</span> could better identify possible English learner and multilingual students than the <span class="hlt">current</span> home language survey. The responses to a proposed and <span class="hlt">current</span> survey were examined for students registering for kindergarten through grade…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70161987','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70161987"><span id="translatedtitle">Phytoplankton bloom dynamics in coastal <span class="hlt">ecosystems</span>: A review with some general lessons from sustained investigation of San Francisco Bay, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cloern, James E.</p> <p>1996-01-01</p> <p>Phytoplankton blooms are prominent features of biological variability in shallow coastal <span class="hlt">ecosystems</span> such as estuaries, lagoons, bays, and tidal rivers. Long-term observation and research in San Francisco Bay illustrates some patterns of phytoplankton spatial and temporal variability and the underlying mechanisms of this variability. Blooms are events of rapid production and accumulation of phytoplankton biomass that are usually responses to changing physical forcings originating in the coastal ocean (e.g., tides), the atmosphere (wind), or on the land surface (precipitation and river runoff). These physical forcings have different timescales of variability, so algal blooms can be short-term episodic events, recurrent seasonal phenomena, or rare events associated with exceptional climatic or hydrologic conditions. The biogeochemical role of phytoplankton primary production is to transform and incorporate reactive inorganic elements into organic forms, and these transformations are rapid and lead to measurable geochemical change during blooms. Examples include the depletion of inorganic nutrients (N, P, Si), supersaturation of oxygen and removal of carbon dioxide, shifts in the isotopic composition of reactive elements (C, N), production of climatically active trace gases (methyl bromide, dimethylsulfide), changes in the chemical form and toxicity of trace metals (As, Cd, Ni, Zn), changes in the biochemical composition and reactivity of the suspended particulate matter, and synthesis of organic matter required for the reproduction and growth of heterotrophs, including bacteria, zooplankton, and benthic consumer animals. Some classes of phytoplankton play special roles in the cycling of elements or synthesis of specific organic molecules, but we have only rudimentary understanding of the forces that select for and promote blooms of these species. Mounting evidence suggests that the natural cycles of bloom variability are being altered on a global scale by human activities including the input of toxic contaminants and nutrients, manipulation of river flows, and translocation of species. This hypothesis will be a key component of our effort to understand global change at the land-sea interface. Pursuit of this hypothesis will require creative approaches for distinguishing natural and anthropogenic sources of phytoplankton population variability, as well as recognition that the modes of human disturbance of coastal bloom cycles operate interactively and cannot be studied as isolated processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996RvGeo..34..127C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996RvGeo..34..127C"><span id="translatedtitle">Phytoplankton bloom dynamics in coastal <span class="hlt">ecosystems</span>: A review with some general lessons from sustained investigation of San Francisco Bay, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cloern, James E.</p> <p>1996-05-01</p> <p>Phytoplankton blooms are prominent features of biological variability in shallow coastal <span class="hlt">ecosystems</span> such as estuaries, lagoons, bays, and tidal rivers. Long-term observation and research in San Francisco Bay illustrates some patterns of phytoplankton spatial and temporal variability and the underlying mechanisms of this variability. Blooms are events of rapid production and accumulation of phytoplankton biomass that are usually responses to changing physical forcings originating in the coastal ocean (e.g., tides), the atmosphere (wind), or on the land surface (precipitation and river runoff). These physical forcings have different timescales of variability, so algal blooms can be short-term episodic events, recurrent seasonal phenomena, or rare events associated with exceptional climatic or hydrologic conditions. The biogeochemical role of phytoplankton primary production is to transform and incorporate reactive inorganic elements into organic forms, and these transformations are rapid and lead to measurable geochemical change during blooms. Examples include the depletion of inorganic nutrients (N, P, Si), supersaturation of oxygen and removal of carbon dioxide, shifts in the isotopic composition of reactive elements (C, N), production of climatically active trace gases (methyl bromide, dimethylsulfide), changes in the chemical form and toxicity of trace metals (As, Cd, Ni, Zn), changes in the biochemical composition and reactivity of the suspended particulate matter, and synthesis of organic matter required for the reproduction and growth of heterotrophs, including bacteria, zooplankton, and benthic consumer animals. Some classes of phytoplankton play special roles in the cycling of elements or synthesis of specific organic molecules, but we have only rudimentary understanding of the forces that select for and promote blooms of these species. Mounting evidence suggests that the natural cycles of bloom variability are being altered on a global scale by human activities including the input of toxic contaminants and nutrients, manipulation of river flows, and translocation of species. This hypothesis will be a key component of our effort to understand global change at the land-sea interface. Pursuit of this hypothesis will require creative approaches for distinguishing natural and anthropogenic sources of phytoplankton population variability, as well as recognition that the modes of human disturbance of coastal bloom cycles operate interactively and cannot be studied as isolated processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ECSS...85..265Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ECSS...85..265Q"><span id="translatedtitle"><span class="hlt">Current</span> status and historical trends of organochlorine pesticides in the <span class="hlt">ecosystem</span> of Deep Bay, South China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qiu, Yao-Wen; Zhang, Gan; Guo, Ling-Li; Cheng, Hai-Rong; Wang, Wen-Xiong; Li, Xiang-Dong; Wai, Onyx W. H.</p> <p>2009-11-01</p> <p>To characterize the <span class="hlt">current</span> status and historical trends in organochlorine pesticides (OCPs) contamination in Deep Bay, an important water body between Hong Kong and mainland China with a Ramsar mangrove wetland (Maipo), samples from seawater, suspended particulate matter (SPM), surface sediment, sediment core and fish were collected to determine the OCPs concentrations. Sediment core dating was accomplished using the 210Pb method. The average concentrations of DDTs, HCHs and chlordanes in water were 1.96, 0.71, 0.81 ng l -1, while in SPM were 36.5, 2.5, 35.7 ng g -1 dry weight, in surface sediment were 20.2, 0.50, 2.4 ng g -1 dry weight, and in fish were 125.4, 0.43, 13.1 ng g -1 wet weight, respectively. DDTs concentrations in various matrices of Deep Bay were intermediate compared with those in other areas. Temporal trends of the targeted OCPs levels in sediment core generally increased from 1948 to 2004, with the highest levels in top or sub-surface sediment. Both DDT composition and historical trends indicated an ongoing fresh DDT input. A positive relationship between the bioconcentration factor (BCF) of target chemicals and the corresponding octanol-water partition coefficient ( Kow), and between the biota-sediment accumulation factors (BSAF) and the Kow were observed in the Bay. The risk assessment indicated that there were potential ecological and human health risks for the target OCPs in Deep Bay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSMOS51A..02L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSMOS51A..02L"><span id="translatedtitle"><span class="hlt">Currents</span> at the sills bounding Delfin Basin in the northern Gulf of <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lopez, M.; Candela, J.</p> <p>2013-05-01</p> <p>One-year-long <span class="hlt">currents</span> at the two sills bounding Delfin basin (maximum depth 900 m), are analyzed. The Delfin (DEL) sill (400 m depth) has the largest mean velocities near the bottom in an overflow that discharges water into the Delfin Basin (roughly towards the head of the gulf), whereas the Ballenas Channel (BC) sill (600 m depth) has the largest mean velocities close to the surface which also flow towards the head of the gulf. The energy of the subinertial <span class="hlt">current</span> fluctuations is also quite different. Most of the energy at the DEL sill is concentrated in the lowest frequencies (periods > 15 days). In the case of the BC sill, the spectra are not red and much of the energy is concentrated at periods ? 15 days except close to the surface, where most the energy is also concentrated in the lowest frequencies associated with the <span class="hlt">current</span> fluctuations of the mean near-surface <span class="hlt">current</span> towards the head of the gulf. Near-bottom <span class="hlt">current</span> fluctuations towards the head of the gulf at the overflow of the DEL sill are well correlated with intermediate and deeper <span class="hlt">currents</span> towards the mouth of the gulf, as well as with surface <span class="hlt">currents</span> towards the head of the gulf at the BC sill for periods ? 20 days. Transport of the overflow also has the largest coherences with near-surface <span class="hlt">currents</span> at the BC sill for periods ? 20 days, but there is also significant coherence with deeper <span class="hlt">currents</span> at the same low frequencies. The relationship between the overflow and the exchange at the BC sill is also clearly borne out by the first empirical mode of <span class="hlt">currents</span> at both locations. This is interpreted as part of the exchange of the northern gulf by which fluctuations of the near-bottom flow into the deepest basins are compensated by fluctuations of the near-surface flow out of the same basins. In addition, near-bottom transport and <span class="hlt">currents</span> at the DEL sill are coherent with deep <span class="hlt">currents</span> at the CB sill at the shorter periods of 10 and 3.2 days. At these periods, there is also good coherence between <span class="hlt">currents</span> at the DEL and CB sills, with temperature fluctuations at the latter site. The overflow has a significant fortnightly modulation, which may not be the result of direct forcing by tidal <span class="hlt">currents</span> but rather, a fortnightly tidal modulation of the <span class="hlt">currents</span> and transport at the San Esteban sill, which lies about 140 km to the southeast and supplies the water for the overflow at the DEL sill.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70164423','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70164423"><span id="translatedtitle">On Lagrangian residual <span class="hlt">currents</span> with applications in south San Francisco Bay, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cheng, Ralph T.; Casulli, Vincenzo</p> <p>1982-01-01</p> <p>The Lagrangian residual circulation has often been introduced as the sum of the Eulerian residual circulation and the Stokes' drift. Unfortunately, this definition of the Lagrangian residual circulation is conceptually incorrect because both the Eulerian residual circulation and the Stokes' drift are Eulerian variables. In this paper a classification of various residual variables are reviewed and properly defined. The Lagrangian residual circulation is then studied by means of a two-stage formulation of a computer model. The tidal circulation is first computed in a conventional Eulerian way, and then the Lagrangian residual circulation is determined by a method patterned after the method of markers and cells. To demonstrate properties of the Lagrangian residual circulation, application of this approach in South San Francisco Bay, <span class="hlt">California</span>, is considered. With the aid of the model results, properties of the Eulerian and Lagrangian residual circulation are examined. It can be concluded that estimation of the Lagrangian residual circulation from Eulerian data may lead to unacceptable error, particularly in a tidal estuary where the tidal excursion is of the same order of magnitude as the length scale of the basin. A direction calculation of the Lagrangian residual circulation must be made and has been shown to be feasible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24493768','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24493768"><span id="translatedtitle">Kaiser Permanente Northern <span class="hlt">California</span>: <span class="hlt">current</span> experiences with internet, mobile, and video technologies.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pearl, Robert</p> <p>2014-02-01</p> <p>The US health care system has been slow to adopt Internet, mobile, and video technologies, which have the capability to engage patients in their own care, increase patients' access to providers, and possibly improve the quality of care while reducing costs. Nevertheless, there are some pockets of progress, including Kaiser Permanente Northern <span class="hlt">California</span> (KPNC). In 2008 KPNC implemented an inpatient and ambulatory care electronic health record system for its 3.4 million members and developed a suite of patient-friendly Internet, mobile, and video tools. KPNC has achieved many successes. For example, the number of virtual "visits" grew from 4.1 million in 2008 to an estimated 10.5 million in 2013. This article describes KPNC's experience with Internet, mobile, and video technologies and the obstacles faced by other health care providers interested in embracing them. The obstacles include the predominant fee-for-service payment model, which does not reimburse for virtual visits; the considerable investment needed to deploy these technologies; and physician buy-in. PMID:24493768</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IJBm..tmp..138M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IJBm..tmp..138M"><span id="translatedtitle">Dynamically downscaling predictions for deciduous tree leaf emergence in <span class="hlt">California</span> under <span class="hlt">current</span> and future climate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Medvigy, David; Kim, Seung Hee; Kim, Jinwon; Kafatos, Menas C.</p> <p>2015-10-01</p> <p>Models that predict the timing of deciduous tree leaf emergence are typically very sensitive to temperature. However, many temperature data products, including those from climate models, have been developed at a very coarse spatial resolution. Such coarse-resolution temperature products can lead to highly biased predictions of leaf emergence. This study investigates how dynamical downscaling of climate models impacts simulations of deciduous tree leaf emergence in <span class="hlt">California</span>. Models for leaf emergence are forced with temperatures simulated by a general circulation model (GCM) at ~200-km resolution for 1981-2000 and 2031-2050 conditions. GCM simulations are then dynamically downscaled to 32- and 8-km resolution, and leaf emergence is again simulated. For 1981-2000, the regional average leaf emergence date is 30.8 days earlier in 32-km simulations than in ~200-km simulations. Differences between the 32 and 8 km simulations are small and mostly local. The impact of downscaling from 200 to 8 km is ~15 % smaller in 2031-2050 than in 1981-2000, indicating that the impacts of downscaling are unlikely to be stationary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020045387','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020045387"><span id="translatedtitle">Seasonal to Decadal-Scale Variability in Satellite Ocean Color and Sea Surface Temperature for the <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mitchell, B. Greg; Kahru, Mati; Marra, John (Technical Monitor)</p> <p>2002-01-01</p> <p>Support for this project was used to develop satellite ocean color and temperature indices (SOCTI) for the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS) using the historic record of CZCS West Coast Time Series (WCTS), OCTS, WiFS and AVHRR SST. The ocean color satellite data have been evaluated in relation to CalCOFI data sets for chlorophyll (CZCS) and ocean spectral reflectance and chlorophyll OCTS and SeaWiFS. New algorithms for the three missions have been implemented based on in-water algorithm data sets, or in the case of CZCS, by comparing retrieved pigments with ship-based observations. New algorithms for absorption coefficients, diffuse attenuation coefficients and primary production have also been evaluated. Satellite retrievals are being evaluated based on our large data set of pigments and optics from CalCOFI.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.A41E0111T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.A41E0111T"><span id="translatedtitle">Fog as an <span class="hlt">ecosystem</span> service: Quantifying fog-mediated reductions in maximum temperature across coastal to inland transects in northern <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Torregrosa, A.; Flint, L. E.; Flint, A. L.; Combs, C.; Peters, J.</p> <p>2013-12-01</p> <p>Several studies have documented the human benefits of temperature cooling derived from coastal fog such as the reduction in the number of hospital visits/emergency response requests from heat stress-vulnerable population sectors or decreased energy consumption during periods when summer maximum temperatures are lower than normal. In this study we quantify the hourly, daily, monthly and seasonal thermal effect of fog and low clouds (FLC) hours on maximum summer temperatures across a northern <span class="hlt">California</span> landscape. The FLC data summaries are calculated from the CIRA (Cooperative Institute for Research in the Atmosphere) 10 year archive that were derived from hourly night and day images using channels 1 (Visible), 2 (3.6 ?m) and 4 (10.7 ?m) NOAA GOES (Geostationary Operational Environmental Satellite). The FLC summaries were analyzed with two sets of site based data, meteorological (met) station-based measurements and downscaled interpolated PRISM data for selected point locations spanning a range of coastal to inland geographic conditions and met station locations. In addition to finding a 0.4 degree C per hour of FLC effect, our results suggest variability related to site specific thermal response. For example, sites closest to the coast have less thermal variability between low cloud and sunny days than sites further from the coast suggesting a much stronger influence of ocean temperature than of FLC thermal dynamics. The thermal relief provided by summertime FLC is equivalent in magnitude to the temperature increase projected by the driest and hottest of regional downscaled climate models using the A2 ('worst') IPCC scenario. Extrapolating these thermal calculations can facilitate future quantifications of the <span class="hlt">ecosystem</span> service provided by summertime low clouds and fog.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PApGe.171.3385A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PApGe.171.3385A"><span id="translatedtitle">Observed and Modeled <span class="hlt">Currents</span> from the Tohoku-oki, Japan and other Recent Tsunamis in Northern <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Admire, Amanda R.; Dengler, Lori A.; Crawford, Gregory B.; Uslu, Burak U.; Borrero, Jose C.; Greer, S. Dougal; Wilson, Rick I.</p> <p>2014-12-01</p> <p>We investigate the <span class="hlt">currents</span> produced by recent tsunamis in Humboldt Bay and Crescent City, <span class="hlt">California</span>. The region is susceptible to both near-field and far-field tsunamis and has a historic record of damaging events. Crescent City Harbor, located approximately 100 kms north of Humboldt Bay, suffered US 28 million in damages from strong <span class="hlt">currents</span> produced by the 2006 Kuril Islands tsunami and an additional US 26 million from the 2011 Japan tsunami. In order to better evaluate these <span class="hlt">currents</span> in northern <span class="hlt">California</span>, we deployed a Nortek Aquadopp 600 kHz 2D acoustic Doppler <span class="hlt">current</span> profiler (ADCP) with a 1-min sampling interval in Humboldt Bay, near the existing National Oceanic and Atmospheric Administration (NOAA) National Ocean Service (NOS) tide gauge station. The instrument recorded the tsunamis produced by the Mw 8.8 Chile earthquake on February 27, 2010 and the Mw 9.0 Japan earthquake on March 11, 2011. One other tsunami was recorded on the Humboldt Bay tide gauge during the period of ADCP operation, but was not visible on the ADCP, suggesting a threshold water level value of about 0.2 m to produce an observable ADCP record. The 2010 tsunami <span class="hlt">currents</span> persisted in Humboldt Bay for approximately 30 h with peak amplitudes of about 0.35 m/s. The 2011 tsunami signal lasted for over 40 h with peak amplitude of 0.84 m/s. The strongest <span class="hlt">currents</span> corresponded to the maximum change in water level approximately 67 min after the initial wave arrival. No damage was observed in Humboldt Bay for either event. In Crescent City, <span class="hlt">currents</span> for the first three and one-half hours of the 2011 Japan tsunami were estimated using security camera video footage from the Harbor Master, approximately 70 m away from the NOAA-NOS tide gauge station. The largest amplitude tide gauge water-level oscillations and most of the damage occurred within this time window. The <span class="hlt">currents</span> reached a velocity of approximately 4.5 m/s and six cycles exceeded 3 m/s during this period. Measured <span class="hlt">current</span> velocities both in Humboldt Bay and in Crescent City were compared to calculated velocities from the Method of Splitting Tsunamis (MOST) numerical model. The frequency and pattern of <span class="hlt">current</span> amplification and decay at both locations are replicated by the MOST model for the first several hours after the tsunami onset. MOST generally underestimates 2011 peak <span class="hlt">current</span> velocities by about 10-30 %, with a few peaks by as much as 50 %. At Humboldt Bay, MOST predicted attenuation of the signal after 4 h but the actual signal persisted at a nearly constant level for at least twice as long. The results from this project demonstrate that ADCPs can effectively record tsunami <span class="hlt">currents</span> for small to moderate events and can be used to calibrate and validate models (i.e., MOST) in order to better understand hazardous tsunami conditions within harbors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRC..119.5123G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRC..119.5123G"><span id="translatedtitle">Effect of coastal-trapped waves and wind on <span class="hlt">currents</span> and transport in the Gulf of <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gutirrez, Manuel O.; Lpez, Manuel; Candela, Julio; Castro, Rubn.; Mascarenhas, Affonso; Collins, Curtis A.</p> <p>2014-08-01</p> <p>Subsurface pressure (SsP) observations from stations inside and outside of the Gulf of <span class="hlt">California</span> (GC) are used to analyze the relationship between low-frequency <span class="hlt">currents</span>, temperature, and transport inside the GC and intraseasonal coastal-trapped waves (CTWs), which propagate poleward along the coast toward the GC. Correlation functions and coherences of SsP stations were consistent with intraseasonal CTWs splitting in two at the mouth of the gulf: one part enters the gulf, propagates around the gulf, and eventually, toward the mouth, and another part that appears to "jump" the mouth of the gulf and travels poleward along the west coast of the peninsula. The correlation and coherence estimates of SsP at Manzanillo with <span class="hlt">currents</span> showed that downwelling CTWs generated along-gulf <span class="hlt">current</span> anomalies toward the head of the gulf at the mainland shelf of the mouth, whereas at Ballenas Channel sill (San Lorenzo sill) these waves generated <span class="hlt">current</span> anomalies toward the mouth near the surface (bottom). At the San Lorenzo (SL) sill, downwelling CTWs increased the near-bottom (400 m) temperature and reduced the bottom transport of deep, fresher, and colder water that flows toward the head of the gulf. Cross-Calibrated Multiplatform winds were used to investigate their relationship with <span class="hlt">currents</span>. The first empirical orthogonal function of the along-gulf wind stress showed that wind blowing toward the head of the gulf generated a reduction of bottom transport toward the head of the gulf through the SL sill, and intensified surface geostrophic <span class="hlt">current</span> fluctuations toward the head of the gulf. There was also significant correlation between inflow bottom transport and outflow surface geostrophic velocities averaged across the gulf, consistent with the exchange pattern for the Northern Gulf.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010108854','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010108854"><span id="translatedtitle">Biogeochemical Response to Mesoscale Physical Forcing in the <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Niiler, Pearn P.; Letelier, Ricardo; Moisan, John R.; Marra, John A. (Technical Monitor)</p> <p>2001-01-01</p> <p>In the first part of the project, we investigated the local response of the coastal ocean <span class="hlt">ecosystems</span> (changes in chlorophyll, concentration and chlorophyll, fluorescence quantum yield) to physical forcing by developing and deploying Autonomous Drifting Ocean Stations (ADOS) within several mesoscale features along the U.S. west coast. Also, we compared the temporal and spatial variability registered by sensors mounted in the drifters to that registered by the sensors mounted in the satellites in order to assess the scales of variability that are not resolved by the ocean color satellite. The second part of the project used the existing WOCE SVP Surface Lagrangian drifters to track individual water parcels through time. The individual drifter tracks were used to generate multivariate time series by interpolating/extracting the biological and physical data fields retrieved by remote sensors (ocean color, SST, wind speed and direction, wind stress curl, and sea level topography). The individual time series of the physical data (AVHRR, TOPEX, NCEP) were analyzed against the ocean color (SeaWiFS) time-series to determine the time scale of biological response to the physical forcing. The results from this part of the research is being used to compare the decorrelation scales of chlorophyll from a Lagrangian and Eulerian framework. The results from both parts of this research augmented the necessary time series data needed to investigate the interactions between the ocean mesoscale features, wind, and the biogeochemical processes. Using the historical Lagrangian data sets, we have completed a comparison of the decorrelation scales in both the Eulerian and Lagrangian reference frame for the SeaWiFS data set. We are continuing to investigate how these results might be used in objective mapping efforts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70156405','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70156405"><span id="translatedtitle">Analysis of <span class="hlt">current</span>-use pesticides in aquatic and terrestrial organisms collected throughout <span class="hlt">California</span>, USA</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Smalling, Kelly L.; Kuivila, Kathyrn M.</p> <p>2010-01-01</p> <p>A wide variety of pesticides are applied concurrently in agricultural and urban areas and transported off site dissolved in water and bound to sediments. But the exposure of aquatic and terrestrial organisms to <span class="hlt">current</span>-use pesticides and the resulting effects are not well understood. One approach is to directly analyze tissue concentrations of contaminants. The overall objective of this study was to develop a sensitive method to analyze <span class="hlt">current</span>-use pesticides with a wide range of Kow's in tissue to better understand the accumulation of these contaminants in different aquatic and terrestrial organisms. This method was then used to analyze <span class="hlt">current</span>-use pesticides in tissues from a variety of organisms from sites with different land-use practices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003DSRII..50.2537H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003DSRII..50.2537H"><span id="translatedtitle">Ocean warming and seabird communities of the southern <span class="hlt">California</span> <span class="hlt">Current</span> System (1987-98): response at multiple temporal scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hyrenbach, K. David; Veit, Richard R.</p> <p>2003-08-01</p> <p>Declines in ocean productivity and shifts in species assemblages along the West Coast of North America during the second half of the XXth century have been attributed to the concurrent warming of the <span class="hlt">California</span> <span class="hlt">Current</span>. This paper addresses changes in the avifauna off southern <span class="hlt">California</span> between May 1987 and September 1998, in response to shifting water mass distributions over short (<1 year) and long (interannual) temporal scales. More specifically, our research focuses on the relative importance of distinct foraging guilds and species assemblages with an affinity for warm and cold water. Over the long term, the avifauna off southern <span class="hlt">California</span> shifted from a 'high-productivity' community typical of eastern boundary upwelling systems, to a 'low-productivity' assemblage similar to those inhabiting the subtropical gyres. Overall seabird abundance decreased; the relative importance of cold-water seabirds that dive in pursuit of prey declined; and warm-water species that feed at the surface and plunge to capture prey became more numerous. These community-level changes are consistent with the northward shifts in species ranges and the declining ocean productivity anticipated as a result of global warming. However, the response of individual taxa with an affinity for warm-water and cold-water conditions has been more difficult to predict, due to differences in species-specific responses to ocean warming. The three cold-water species investigated (Sooty Shearwater Puffinus griseus, Cassin's Auklet Ptychoramphus aleuticus, and Rhinoceros Auklet Cerorhinca monocerata) decreased in abundance during this study. On the other hand, only one of the six warm-water species considered (Pink-footed Shearwater, Puffinus creatopus) increased significantly over the long term. Yet, the warm-water Leach's Storm-petrel ( Oceanodroma leucorhoa) increased between 1987 and 1993, and then declined between 1994 and 1998. Moreover, cross-correlations between seasonally adjusted anomalies of bird abundance and ocean temperature revealed that seabirds responded differently to ocean warming over intermediate (1-8 years), and long (8-12 years) time scales. We hypothesize that this nonlinear behavior of seabird populations in response to ocean warming is caused by the juxtaposition of distinct behavioral and demographic responses operating at different temporal scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10179469','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10179469"><span id="translatedtitle">Modeling the response of the <span class="hlt">California</span> <span class="hlt">Current</span> system to global greenhouse warming. Final report to the National Institute for Global Environmental Change (August 1993)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pares-Sierra, A.; Somerville, R.C.J.</p> <p>1993-12-31</p> <p>This is the final report for the project ``Modeling the Response of the <span class="hlt">California</span> <span class="hlt">Current</span> System to Global Greenhouse Warming,`` supported 1990 and 1991 by NIGEC. The scientists involved are Dr. Richard C.J. Somerville and Alejandro Paries-Sierra of Scripps Institution of Oceanography, UCSD. A copy of papers submitted to the Journal of Physical Oceanography, and Geofisica Internacional that were supported in part or whole by WEST-GEC, as well as a summary of a talk delivered at the XX General Assembly of the IUGG, Vienna (1991) are appended to this report. The objective of the research was to improve the understanding of the response of the <span class="hlt">California</span> <span class="hlt">Current</span> system to the large-scale anomalous forcing thought to be associated with greenhouse warming. The authors viewed this as a necessary initial step in the study of the <span class="hlt">California</span> climate response to global change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMS...147...94K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMS...147...94K"><span id="translatedtitle">Optimized multi-satellite merger of primary production estimates in the <span class="hlt">California</span> <span class="hlt">Current</span> using inherent optical properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kahru, Mati; Jacox, Michael G.; Lee, Zhongping; Kudela, Raphael M.; Manzano-Sarabia, Marlenne; Mitchell, B. Greg</p> <p>2015-07-01</p> <p>Building a multi-decadal time series of large-scale estimates of net primary production (NPP) requires merging data from multiple ocean color satellites. The primary product of ocean color sensors is spectral remote sensing reflectance (Rrs). We found significant differences (13-18% median absolute percent error) between Rrs estimates at 443 nm of different satellite sensors. These differences in Rrs are transferred to inherent optical properties and further on to estimates of NPP. We estimated NPP for the <span class="hlt">California</span> <span class="hlt">Current</span> region from three ocean color sensors (SeaWiFS, MODIS-Aqua and MERIS) using a regionally optimized absorption based primary production model (Aph-PP) of Lee et al. (2011). Optimization of the Aph-PP model was required for each individual satellite sensor in order to make NPP estimates from different sensors compatible with each other. While the concept of Aph-PP has advantages over traditional chlorophyll-based NPP models, in practical application even the optimized Aph-PP model explained less than 60% of the total variance in NPP which is similar to other NPP algorithms. Uncertainties in satellite Rrs estimates as well as uncertainties in parameters representing phytoplankton depth distribution and physiology are likely to be limiting our <span class="hlt">current</span> capability to accurately estimate NPP from space. Introducing a generic vertical profile for phytoplankton improved slightly the skill of the Aph-PP model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS33B1350E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS33B1350E"><span id="translatedtitle">Seasonal and Interannual Variability in the <span class="hlt">California</span> <span class="hlt">Current</span> System over the Washington Continental Slope observed with Seagliders</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eriksen, C. C.; Lee, C. M.; Perry, M. J.</p> <p>2008-12-01</p> <p>Nearly continuous Seaglider repeat sections over the Washington continental slope since August 2003 reveal seasonal and interannual patterns of circulation, oxygen and phytoplankton distribution. Structure in the upper 1 km of the water column has been resolved to ~5 km along sections completed roughly fortnightly using Seaglider long-range autonomous underwater vehicles. More than 11,000 profiles of temperature, salinity, dissolved oxygen, chlorophyll fluorescence and optical backscatter on over 25,000 km of survey track have been collected in 5 years along a pair of sections normal to the coast. Both seasonal and interannual signals are prominent in the observations. Isopycnal tilts delineating the equatorward <span class="hlt">California</span> <span class="hlt">Current</span> offshore and the poleward inshore countercurrent reverse seasonally. Alongshore <span class="hlt">current</span> fluctuations as well as property surfaces tend to propagate offshore near the speed of a gravest mode long Rossby wave. Annual signals are nearly oppositely phased from the continental shelf edge to the end of the survey track, 220-240 km offshore. Interannual differences in water type and depth averaged transport in the upper 1 km are apparent. Alongshore transport variations are strongly interannual, amounting to a few Sverdrups poleward or equatorward in different years. A particularly large equatorward transport pulse was observed over a several month episode centered on January 2007, where average transports exceeded 10 Sverdrups with a few fortnightly estimates exceeding 20 Sverdrups.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3701056','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3701056"><span id="translatedtitle"><span class="hlt">Current</span> Status and Future Prospects for the Assessment of Marine and Coastal <span class="hlt">Ecosystem</span> Services: A Systematic Review</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liquete, Camino; Piroddi, Chiara; Drakou, Evangelia G.; Gurney, Leigh; Katsanevakis, Stelios; Charef, Aymen; Egoh, Benis</p> <p>2013-01-01</p> <p>Background Research on <span class="hlt">ecosystem</span> services has grown exponentially during the last decade. Most of the studies have focused on assessing and mapping terrestrial <span class="hlt">ecosystem</span> services highlighting a knowledge gap on marine and coastal <span class="hlt">ecosystem</span> services (MCES) and an urgent need to assess them. Methodology/Principal Findings We reviewed and summarized existing scientific literature related to MCES with the aim of extracting and classifying indicators used to assess and map them. We found 145 papers that specifically assessed marine and coastal <span class="hlt">ecosystem</span> services from which we extracted 476 indicators. Food provision, in particular fisheries, was the most extensively analyzed MCES while water purification and coastal protection were the most frequently studied regulating and maintenance services. Also recreation and tourism under the cultural services was relatively well assessed. We highlight knowledge gaps regarding the availability of indicators that measure the capacity, flow or benefit derived from each <span class="hlt">ecosystem</span> service. The majority of the case studies was found in mangroves and coastal wetlands and was mainly concentrated in Europe and North America. Our systematic review highlighted the need of an improved <span class="hlt">ecosystem</span> service classification for marine and coastal systems, which is herein proposed with definitions and links to previous classifications. Conclusions/Significance This review summarizes the state of available information related to <span class="hlt">ecosystem</span> services associated with marine and coastal <span class="hlt">ecosystems</span>. The cataloging of MCES indicators and the integrated classification of MCES provided in this paper establish a background that can facilitate the planning and integration of future assessments. The final goal is to establish a consistent structure and populate it with information able to support the implementation of biodiversity conservation policies. PMID:23844080</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B22C..04P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B22C..04P"><span id="translatedtitle">Seasonal and spatial variation of bug flux in a northern <span class="hlt">California</span> drainage network under a Mediterranean climate: implications for reciprocal subsidies between coupled <span class="hlt">ecosystems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Power, M. E.; Moreno-Mateos, D.; Uno, H.; Bode, C.; Rainey, W.</p> <p>2010-12-01</p> <p>Background/Question/Methods. Network configuration of river drainages affects ecological exchange between mainstem channels and smaller tributaries, and between coupled terrestrial and aquatic habitats. Seasonal complementarity of fluxes may enhance predator densities and persistence in linked habitats under continental climate regimes (Nakano and Murakami 2001). In a Mediterranean watershed (the upper South Fork Eel River of Northern <span class="hlt">California</span> (39°44’N, 123°37’W)), we studied spatial and seasonal patterns in insect fluxes among river, wetland, and forest habitats. We quantified insect emergence with vertical traps, and lateral fluxes between six wetland and eight river reaches and the upland forest adjacent to each. Insect horizontal fluxes were sampled using sticky traps along 50-150 m transects from the moister to the dryer habitats. We also studied vertical gradients of insect fluxes over rivers (up to 7 m) and in the forest (up to 40 m). Ca. 1800 traps and 40,000 insects were quantified. Results/Conclusions. In contrast to linked forest-river <span class="hlt">ecosystems</span> in Hokkaido, peaks of insect fluxes in aquatic versus terrestrial habitats of the Eel River basin were less offset, and the seasonality of terrestrial versus river peaks was reversed. From late April through May, when the whole landscape was moist, there was no spatial variation in insect abundance-activity along forest, wetland, or river transects, and abundances averaged 315 insects m-2d-1. As the uplands dried out, from June to September, insect abundance peaked in wetlands and near the river, but dropped in the forest to average 32 insects m-2d-1 . The wetlands, with three abundance peaks distributed through spring, summer, and fall, maintained insect fluxes when river and forest fluxes were low. Vertically arrayed sticky traps over the river documented maximal insect activity-abundance near the water surface. In some positions, movements appeared random (equal downstream and upstream fluxes), but at other sites movements were strongly directional. For example, Amaletus mayflies that reared as larvae in the productive mainstem swarmed as adults into a small, dark, steep tributary, where extensive crusts of dead adults over tributary pools suggested that they mated and died. We are investigating how insectivorous birds and bats track and respond to these seasonal shifts in food supply points and spatial fluxes through the basin network of linked habitats.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPA21A..02V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPA21A..02V"><span id="translatedtitle">Is it restoration or reconciliation? <span class="hlt">California</span>'s experience restoring the Sacramento - San Joaquin River Delta provides lessons learned and pathways forward to sustain critical <span class="hlt">ecosystem</span> functions and services in a highly managed riverine delta.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Viers, J. H.; Kelsey, R.</p> <p>2014-12-01</p> <p>Reconciling the needs of nature and people in <span class="hlt">California</span>'s Sacramento - San Joaquin River Delta represents one of the most critical <span class="hlt">ecosystem</span> management imperatives in western North America. Over 150 years the Delta has been managed for near-term human benefits and in the process 95% of riverine and deltaic wetlands have been lost throughout the region. Despite extensive land conversion and alteration of hydrological and physical processes, the Delta remains important habitat for migratory birds and is home to over 60% of <span class="hlt">California</span>'s native fish species. It is also the waterwheel for the state's vast water distribution network and is maintained by a system of constructed levees that are at risk from catastrophic failure due to sea level rise, floods, and/or seismic activity. Such a collapse would have dire consequences for > 25M humans and world's 10th largest economy that depend on its freshwater. Thus, the ultimate cost of this <span class="hlt">ecosystem</span> alteration and simplification is a riverscape that is no longer reliable for nature or people. For 30 years, attempts to 'restore' Delta <span class="hlt">ecosystems</span> and improve reliability have met with mixed results. For example, reconnection of floodplains to floodwaters has resulted in improved ecological health for native fishes and recharge to localized aquifers. Uncoordinated releases of discharges below dams, however, have resulted in diminished water quality and populations of indicator species. Attempts to create wildlife friendly farms have been countered by an increase in perennial agriculture and commensurate increases in irrigation water demand. From these lessons learned, we demonstrate three key components of a reconciled Delta that will be necessary in the future: 1) full restoration of critical habitats, reconnecting land and water to rebuild <span class="hlt">ecosystem</span> function; 2) landscape redesign, incorporating natural and engineered infrastructure to create a biologically diverse, resilient landscape to support both agriculture and natural <span class="hlt">ecosystems</span>, while reducing the impacts of climate change; and 3) recognition that some <span class="hlt">ecosystem</span> components, including less resilient species, may be lost and other novel components may emerge. These findings serve to reconcile conflicting demands and restoring <span class="hlt">ecosystem</span> functions in highly altered wetland landscapes worldwide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1715606M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1715606M"><span id="translatedtitle">Is the <span class="hlt">current</span> increase in fire recurrence causing a shift in the soil fertility of Iberian <span class="hlt">ecosystems</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mayor, Ángeles G.; Keizer, Jan Jacob; González-Pelayo, Óscar; Valdecantos, Alejandro; Vallejo, Ramón; de Ruiter, Peter</p> <p>2015-04-01</p> <p>Since the mid of the last century fire recurrence has increased in the Iberian peninsula and the overall Mediterranean basin due to changes in land use and climate. The warmer and drier climate projected for this region will further increase the risk of wildfire occurrence and of increasing fire recurrence. Although the impact of wildfires on soil nutrient content in this region has been extensively studied, still few works have assessed this impact on the basis of fire recurrence. This study assesses the changes in soil nutrient status of two Iberian <span class="hlt">ecosystems</span>, Várzea (N Portugal) and Valencia (E Spain), affected by different levels of fire recurrence and where short inter-fire periods have promoted a transition from pine woodlands to shrublands. Trends towards soil fertility loss with increasing fire recurrence (one, two, three or four fires in 37 years) were observed in the two study sites. The sites differed when soil fertility of areas burned several times were compared with long unburned references. In Valencia, overall soil fertility of the surface mineral soil was lower in areas burned two or three times than in long unburned areas, twenty and eight years after the last fire, respectively. On the contrary, total organic matter in Várzea was higher in burned than in unburned soils one year after the occurrence of one or four fires. However, a negative impact of fire was observed for integrated indicators of soil quality, such as hot-water carbon and potentially mineralizable nitrogen, suggesting that fire also had an adverse effect on substrate quality in Várzea. Our results suggest that the <span class="hlt">current</span> trend of increasing fire recurrence in Southern Europe may result in losses or alterations of soil organic matter, particularly when fire promotes a transition from pine woodland to shrubland.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP53B1215H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP53B1215H"><span id="translatedtitle">Linkages Between Upwelling and Shell Characteristics of Mytilus californianus: Morphology and Stable Isotope (δ13C, δ18O) Signatures of a Carbonate Archive from the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hosfelt, J. D.; Hill, T. M.; Russell, A. D.; Bean, J. R.; Sanford, E.; Gaylord, B.</p> <p>2014-12-01</p> <p>Many calcareous organisms are known to record the ambient environmental conditions in which they grow, and their calcium carbonate skeletons are often valuable archives of climate records. Mytilus californianus, a widely distributed species of intertidal mussel, experiences a spatial mosaic of oceanographic conditions as it grows within the <span class="hlt">California</span> <span class="hlt">Current</span> System. Periodic episodes of upwelling bring high-CO2 waters to the surface, during which <span class="hlt">California</span> coastal waters are similar to projected conditions and act as a natural analogue to future ocean acidification. To examine the link between upwelling and shell characteristics of M. californianus, we analyzed the morphology and stable isotope (δ13C, δ18O) signatures of mussel specimens collected live from seven study sites within the <span class="hlt">California</span> <span class="hlt">Current</span> System. Morphometric analyses utilized a combination of elliptic Fourier analysis and shell thickness measurements to determine the influence of low pH waters on the growth morphology and ecological fitness of M. californianus. These geochemical and morphological analyses were compared with concurrent high-resolution environmental (T, S, pH, TA, DIC) records from these seven study sites from 2010-2013. With appropriate calibration, new archives from modern M. californianus shells could provide a valuable tool to enable environmental reconstructions within the <span class="hlt">California</span> <span class="hlt">Current</span> System. These archives could in turn be used to predict the future consequences of continuing ocean acidification, as well as reconstruct past (archeological) conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/sir/2009/5090/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/sir/2009/5090/"><span id="translatedtitle">Direct-<span class="hlt">Current</span> Resistivity Profiling at the Pecos River <span class="hlt">Ecosystem</span> Project Study Site near Mentone, Texas, 2006</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Teeple, Andrew P.; McDonald, Alyson K.; Payne, Jason D.; Kress, Wade H.</p> <p>2009-01-01</p> <p>The U.S. Geological Survey, in cooperation with Texas A&M University AgriLife, did a surface geophysical investigation at the Pecos River <span class="hlt">Ecosystem</span> Project study site near Mentone in West Texas intended to determine shallow (to about 14 meters below the water [river] surface) subsurface composition (lithology) in and near treated (eradicated of all saltcedar) and control (untreated) riparian zone sites during June-August 2006. Land-based direct-<span class="hlt">current</span> resistivity profiling was applied in a 240-meter section of the riverbank at the control site, and waterborne direct-<span class="hlt">current</span> continuous resistivity profiling (CRP) was applied along a 2.279-kilometer reach of the river adjacent to both sites to collect shallow subsurface resistivity data. Inverse modeling was used to obtain a nonunique estimate of the true subsurface resistivity from apparent resistivity calculated from the field measurements. The land-based survey showed that the sub-surface at the control site generally is of relatively low resis-tivity down to about 4 meters below the water surface. Most of the section from about 4 to 10 meters below the water surface is of relatively high resistivity. The waterborne CRP surveys convey essentially the same electrical representation of the lithology at the control site to 10 meters below the water surface; but the CRP surveys show considerably lower resistivity than the land-based survey in the subsection from about 4 to 10 meters below the water surface. The CRP surveys along the 2.279-kilometer reach of the river adjacent to both the treated and control sites show the same relatively low resistivity zone from the riverbed to about 4 meters below the water surface evident at the control site. A slightly higher resistivity zone is observed from about 4 to 14 meters below the water surface along the upstream approximately one-half of the profile than along the downstream one-half. The variations in resistivity could not be matched to variations in lithology because sufficient rock samples were not available.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70147344','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70147344"><span id="translatedtitle">Analysis of projected water availability with <span class="hlt">current</span> basin management plan, Pajaro Valley, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hanson, Randall T.; Lockwood, Brian; Schmid, Wolfgang</p> <p>2014-01-01</p> <p>The analysis of projected supply and demand for the Pajaro Valley indicate that the <span class="hlt">current</span> water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations and assumptions of 2009 urban water demand and land use. Water supplied directly from precipitation, and indirectly from reuse, captured local runoff, and groundwater is necessary but inadequate to satisfy agricultural demand without coastal and regional storage depletion that facilitates seawater intrusion. These facilities reduce potential seawater intrusion by about 45% with groundwater levels in the four regions served by the CDS projected to recover to levels a few feet above sea level. The projected recoveries are not high enough to prevent additional seawater intrusion during dry-year periods or in the deeper aquifers where pumpage is greater. While these facilities could reduce coastal pumpage by about 55% of the historical 2000–2009 pumpage for these regions, and some of the water is delivered in excess of demand, other coastal regions continue to create demands on coastal pumpage that will need to be replaced to reduce seawater intrusion. In addition, inland urban and agricultural demands continue to sustain water levels below sea level causing regional landward gradients that also drive seawater intrusion. Seawater intrusion is reduced by about 45% but it supplies about 55% of the recovery of groundwater levels in the coastal regions served by the CDS. If economically feasible, water from summer agricultural runoff and tile-drain returnflows could be another potential local source of water that, if captured and reused, could offset the imbalance between supply and demand as well as reducing discharge of agricultural runoff into the National Marine Sanctuary of Monterey Bay. A BMP update (2012) identifies projects and programs that will fund a conservation program and will provide additional, alternative water sources to reduce or replace coastal and inland pumpage, and to replenish the aquifers with managed aquifer recharge in an inland portion of the Pajaro Valley.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PrOce.134...77P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PrOce.134...77P"><span id="translatedtitle">Changes in zooplankton habitat, behavior, and acoustic scattering characteristics across glider-resolved fronts in the Southern <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Powell, Jesse R.; Ohman, Mark D.</p> <p>2015-05-01</p> <p>We report cross-frontal changes in the characteristics of plankton proxy variables measured by autonomous Spray ocean gliders operating within the Southern <span class="hlt">California</span> <span class="hlt">Current</span> System (SCCS). A comparison of conditions across the 154 positive frontal gradients (i.e., where density of the surface layer decreased in the offshore direction) identified from six years of continuous measurements showed that waters on the denser side of the fronts typically showed higher Chl-a fluorescence, shallower euphotic zones, and higher acoustic backscatter than waters on the less dense side. Transitions between these regions were relatively abrupt. For positive fronts the amplitude of Diel Vertical Migration (DVM), inferred from a 3-beam 750 kHz acoustic Doppler profiler, increased offshore of fronts and covaried with optical transparency of the water column. Average interbeam variability in acoustic backscatter also changed across many positive fronts within 3 depth strata (0-150 m, 150-400 m, and 400-500 m), revealing a front-related change in the acoustic scattering characteristics of the assemblages. The extent of vertical stratification of distinct scattering assemblages was also more pronounced offshore of positive fronts. Depth-stratified zooplankton samples collected by Mocness nets corroborated the autonomous measurements, showing copepod-dominated assemblages and decreased zooplankton body sizes offshore and euphausiid-dominated assemblages with larger median body sizes inshore of major frontal features.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IzPSE..52..117B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IzPSE..52..117B"><span id="translatedtitle">The evolution of the stress state in Southern <span class="hlt">California</span> based on the geomechanical model and <span class="hlt">current</span> seismicity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bondur, V. G.; Garagash, I. A.; Gokhberg, M. B.; Rodkin, M. V.</p> <p>2016-01-01</p> <p>A three-dimensional geomechanical model of Southern <span class="hlt">California</span>, which includes the mountain topography, fault tectonics, and main structural boundaries (the top of the lower crust and the Moho), is developed. The main stress state of the model is determined by the own weight of the rocks and by the horizontal tectonic motions identified from the GPS observations. The model enables tracking the changes which occur in the stress-strain state of the crust due to the evolution of the seismic process. As the input data, the model uses the <span class="hlt">current</span> seismicity and treats each earthquake as a new defect in the Earth's crust which brings about the redistribution of strains, elastic energy density, and yield stress of the crust. Monitoring the variations in the stress state of the crust and lithosphere arising in response to the seismic process shows that the model is suitable for forecasting the enhancement in seismic activity of the region and delineating the earthquake-prone areas with a reasonable probability on a given time interval.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRC..120.4654B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRC..120.4654B"><span id="translatedtitle">Enhanced silica ballasting from iron stress sustains carbon export in a frontal zone within the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brzezinski, Mark A.; Krause, Jeffrey W.; Bundy, Randelle M.; Barbeau, Katherine A.; Franks, Peter; Goericke, Ralf; Landry, Michael R.; Stukel, Michael R.</p> <p>2015-07-01</p> <p>Nutrient dynamics, phytoplankton rate processes, and export were examined in a frontal region between an anticyclone and a pair of cyclones 120 km off the coast in the southern <span class="hlt">California</span> <span class="hlt">Current</span> System (sCCS). Low silicic acid: nitrate ratios (Si:N) and high nitrate to iron ratios (N:Fe) characteristic of Fe-limiting conditions in the sCCS were associated with the northern cyclone and with the transition zone between the cyclones and the anticyclone. Phytoplankton growth in low-Si:N, high-N:Fe waters responded strongly to added Fe, confirming growth limitation by Fe of the diatom-dominated phytoplankton community. Low Si:N waters had low biogenic silica content, intermediate productivity, but high export compared to intermediate Si:N waters indicating increased export efficiency under Fe stress. Biogenic silica and particulate organic carbon (POC) export were both high beneath low Si:N waters with biogenic silica export being especially enhanced. This suggests that relatively high POC export from low Si:N waters was supported by silica ballasting from Fe-limited diatoms. Higher POC export efficiency in low Si:N waters may have been further enhanced by lower rates of organic carbon remineralization due to reduced grazing of more heavily armored diatoms growing under Fe stress. The results imply that Fe stress can enhance carbon export, despite lowering productivity, by driving higher export efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH13A3726A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH13A3726A"><span id="translatedtitle">Measuring Possible Tsunami <span class="hlt">Currents</span> from the April 1, 2014 Mw 8.2 Chile Earthquake in Crescent City, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Admire, A. R.; Crawford, G. B.; Dengler, L. A.</p> <p>2014-12-01</p> <p>Crescent City, <span class="hlt">California</span> has a long history of damaging tsunamis. Thirty-nine tsunamis have been recorded since 1933, including five that caused damage. Crescent City's harbor and small boat basin are particularly vulnerable to strong <span class="hlt">currents</span>. Humboldt State University has installed Acoustic Doppler Profilers (ADPs) in order to directly measure water pressure fluctuations and <span class="hlt">currents</span> caused by tsunamis. An instrument in Humboldt Bay, ~100 km south of Crescent City, recorded tsunamis generated by the 2010 Mw 8.7 Chile and 2011 Mw 9.0 Japan earthquakes and demonstrated the usefulness of ADPs in measuring tsunami <span class="hlt">currents</span>. In 2013, an ADP was deployed in Crescent City's harbor adjacent to the NOAA tide gauge. On April 1, 2014, a Mw 8.2 earthquake occurred in northern Chile, producing a modest Pacific-wide tsunami and a 16 cm peak amplitude on the Crescent City tide gauge. We analyze the ADP data before and during the expected arrival of the April 2 tsunami to see if a tsunami signal is present. Tidal <span class="hlt">currents</span> are generally small (5 cm/s or less). For two months before the tsunami, intermittent, high-frequency variability is present in velocity and pressure at periods on the order of 20, 9 and 5 min, which compare favorably to modal periods predicted using some simplified models of open-ended basins. For several hours after the tsunami arrival on April 2, spectral power levels in velocity and pressure around the 20 min period are notably enhanced. These results suggest that: (1) the observed periods of enhanced variability represent the first three modes (n=0, 1 and 2) of free oscillations in the harbor, (2) the dominant period of (non-tidal) oscillations observed during the April 2, 2014 tsunami (~20 min) and during previous tsunamis (e.g., the water level record for the March 11, 2011 tsunami; also ~20 min) represents harbor resonance corresponding to the lowest order mode, and (3) this event is very near the ADP limit of detectability with peak tsunami <span class="hlt">currents</span> of 5-10 cm/s and higher frequency variability and instrument noise root-mean-squared amplitude of 4-5 cm/s.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JHyd..519..131H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JHyd..519..131H"><span id="translatedtitle">Analysis of projected water availability with <span class="hlt">current</span> basin management plan, Pajaro Valley, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hanson, R. T.; Lockwood, B.; Schmid, Wolfgang</p> <p>2014-11-01</p> <p>The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within “water-balance subregions” (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori. The analysis of projected supply and demand for the Pajaro Valley indicate that the <span class="hlt">current</span> water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations and assumptions of 2009 urban water demand and land use. Water supplied directly from precipitation, and indirectly from reuse, captured local runoff, and groundwater is necessary but inadequate to satisfy agricultural demand without coastal and regional storage depletion that facilitates seawater intrusion. These facilities reduce potential seawater intrusion by about 45% with groundwater levels in the four regions served by the CDS projected to recover to levels a few feet above sea level. The projected recoveries are not high enough to prevent additional seawater intrusion during dry-year periods or in the deeper aquifers where pumpage is greater. While these facilities could reduce coastal pumpage by about 55% of the historical 2000-2009 pumpage for these regions, and some of the water is delivered in excess of demand, other coastal regions continue to create demands on coastal pumpage that will need to be replaced to reduce seawater intrusion. In addition, inland urban and agricultural demands continue to sustain water levels below sea level causing regional landward gradients that also drive seawater intrusion. Seawater intrusion is reduced by about 45% but it supplies about 55% of the recovery of groundwater levels in the coastal regions served by the CDS. If economically feasible, water from summer agricultural runoff and tile-drain returnflows could be another potential local source of water that, if captured and reused, could offset the imbalance between supply and demand as well as reducing discharge of agricultural runoff into the National Marine Sanctuary of Monterey Bay. A BMP update (2012) identifies projects and programs that will fund a conservation program and will provide additional, alternative water sources to reduce or replace coastal and inland pumpage, and to replenish the aquifers with managed aquifer recharge in an inland portion of the Pajaro Valley.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006DSRII..53..399Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006DSRII..53..399Y"><span id="translatedtitle">Spring-time distributions of migratory marine birds in the southern <span class="hlt">California</span> <span class="hlt">Current</span>: Oceanic eddy associations and coastal habitat hotspots over 17 years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yen, P. P. W.; Sydeman, W. J.; Bograd, S. J.; Hyrenbach, K. D.</p> <p>2006-02-01</p> <p>We used a 17-year time series of shipboard observations to address the hypothesis that marine birds associate with persistent hydrographic features in the southern <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS). Overall, approximately 27,000 km of ocean habitat were surveyed, averaging 1600 km per cruise. We identified mesoscale features (eddy centers and the core of the <span class="hlt">California</span> <span class="hlt">Current</span>), based on dynamic height anomalies, and considered habitat associations for seven migratory seabird species: black-footed albatross ( Phoebastria nigripes), Cook's petrel ( Pterodroma cookii), Leach's storm-petrel ( Oceanodroma leucorhoa), dark shearwaters (mainly sooty shearwater Puffinus griseus, with a few short-tailed shearwaters Puffinus tenuirostris), northern fulmar ( Fulmarus glacialis), red phalarope ( Phalaropus fulicaria), and red-necked phalarope ( Phalaropus lobatus). We explored associations (presence/absence and density relationships) of marine birds with mesoscale features (eddies, <span class="hlt">current</span> jet) and metrics of primary productivity (chlorophyll a and nitrate concentrations). Mesoscale eddies were consistently identified in the study region, but were spatially and temporally variable. The resolved eddies were large-scale features associated with meanders of the equatorward-flowing <span class="hlt">California</span> <span class="hlt">Current</span>. Cook's petrel was found offshore with no specific habitat affinities. Black-footed albatross, red phalarope, and Leach's storm petrel were found in association with offshore eddies and/or the core of the <span class="hlt">California</span> <span class="hlt">Current</span>, but the functional relationship for these species varied, possibly reflecting differences in flight capabilities. The more coastal species, including the shearwaters, fulmar, and red-necked phalarope, were positively associated with proxies of primary productivity. Of the hydrographic habitats considered, the upwelling region of Point Conception appears to be an important "hotspot" of sustained primary production and marine bird concentrations. Point Conception and other similar coastal locations (upwelling cells) may warrant protection as key foraging grounds for seabirds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PrOce.137..103A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PrOce.137..103A"><span id="translatedtitle">Anomalous ichthyoplankton distributions and concentrations in the northern <span class="hlt">California</span> <span class="hlt">Current</span> during the 2010 El Nio and La Nia events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Auth, Toby D.; Brodeur, Richard D.; Peterson, Jay O.</p> <p>2015-09-01</p> <p>In late spring of 2010, the northern <span class="hlt">California</span> <span class="hlt">Current</span> (NCC) experienced a transition from El Nio to La Nia conditions resulting in anomalous distributions and concentrations within the ichthyoplankton community. We analyzed larval fish data collected during the four months before and after this transition and compared them to data from three previous studies conducted in the NCC. In one comparison, concentrations of larvae collected during winter from stations 2 to 46 km offshore along the central Oregon coast were higher in 2010 than in any other year from 1998 to 2011. In a second comparison of nearshore larvae collected during six periods (1971-1972, 1978, 1983, 1998, 1999-2002, and 2003-2005) previous to 2010, concentrations of total larvae and most dominant larval taxa were higher during the winter/spring and lower during the summer/fall seasons in 2010 (corresponding to the shift from El Nio to La Nia conditions) than during similar seasons in any other annual period. In a third comparison, larvae collected from stations 21 to 102 km offshore along the southern Washington to south-central Oregon coast in May 2010, at the end of the El Nio event, were found in higher concentrations than during any May from 2004 to 2009 and 2011. The high concentration of larvae in the winter and spring of 2010 was likely the direct result of El Nio and warm-ocean conditions (high values of the MEI, NOI, and PDO) along with strong downwelling and onshore transport that increased the abundance of offshore taxa over the shelf. Continued monitoring of the NCC is warranted as El Nio effects on larval fish observed in the past may not be indicative of future effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4201512','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4201512"><span id="translatedtitle">Carbon and Nitrogen Isotopes from Top Predator Amino Acids Reveal Rapidly Shifting Ocean Biochemistry in the Outer <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ruiz-Cooley, Rocio I.; Koch, Paul L.; Fiedler, Paul C.; McCarthy, Matthew D.</p> <p>2014-01-01</p> <p>Climatic variation alters biochemical and ecological processes, but it is difficult both to quantify the magnitude of such changes, and to differentiate long-term shifts from inter-annual variability. Here, we simultaneously quantify decade-scale isotopic variability at the lowest and highest trophic positions in the offshore <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS) by measuring δ15N and δ13C values of amino acids in a top predator, the sperm whale (Physeter macrocephalus). Using a time series of skin tissue samples as a biological archive, isotopic records from individual amino acids (AAs) can reveal the proximate factors driving a temporal decline we observed in bulk isotope values (a decline of ≥1 ‰) by decoupling changes in primary producer isotope values from those linked to the trophic position of this toothed whale. A continuous decline in baseline (i.e., primary producer) δ15N and δ13C values was observed from 1993 to 2005 (a decrease of ∼4‰ for δ15N source-AAs and 3‰ for δ13C essential-AAs), while the trophic position of whales was variable over time and it did not exhibit directional trends. The baseline δ15N and δ13C shifts suggest rapid ongoing changes in the carbon and nitrogen biogeochemical cycling in the offshore CCS, potentially occurring at faster rates than long-term shifts observed elsewhere in the Pacific. While the mechanisms forcing these biogeochemical shifts remain to be determined, our data suggest possible links to natural climate variability, and also corresponding shifts in surface nutrient availability. Our study demonstrates that isotopic analysis of individual amino acids from a top marine mammal predator can be a powerful new approach to reconstructing temporal variation in both biochemical cycling and trophic structure. PMID:25329915</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25329915','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25329915"><span id="translatedtitle">Carbon and nitrogen isotopes from top predator amino acids reveal rapidly shifting ocean biochemistry in the outer <span class="hlt">California</span> <span class="hlt">Current</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ruiz-Cooley, Rocio I; Koch, Paul L; Fiedler, Paul C; McCarthy, Matthew D</p> <p>2014-01-01</p> <p>Climatic variation alters biochemical and ecological processes, but it is difficult both to quantify the magnitude of such changes, and to differentiate long-term shifts from inter-annual variability. Here, we simultaneously quantify decade-scale isotopic variability at the lowest and highest trophic positions in the offshore <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS) by measuring δ15N and δ13C values of amino acids in a top predator, the sperm whale (Physeter macrocephalus). Using a time series of skin tissue samples as a biological archive, isotopic records from individual amino acids (AAs) can reveal the proximate factors driving a temporal decline we observed in bulk isotope values (a decline of ≥1 ‰) by decoupling changes in primary producer isotope values from those linked to the trophic position of this toothed whale. A continuous decline in baseline (i.e., primary producer) δ15N and δ13C values was observed from 1993 to 2005 (a decrease of ∼4‰ for δ15N source-AAs and 3‰ for δ13C essential-AAs), while the trophic position of whales was variable over time and it did not exhibit directional trends. The baseline δ15N and δ13C shifts suggest rapid ongoing changes in the carbon and nitrogen biogeochemical cycling in the offshore CCS, potentially occurring at faster rates than long-term shifts observed elsewhere in the Pacific. While the mechanisms forcing these biogeochemical shifts remain to be determined, our data suggest possible links to natural climate variability, and also corresponding shifts in surface nutrient availability. Our study demonstrates that isotopic analysis of individual amino acids from a top marine mammal predator can be a powerful new approach to reconstructing temporal variation in both biochemical cycling and trophic structure. PMID:25329915</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP33A1204A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP33A1204A"><span id="translatedtitle">Links between carbonate productivity and ENSO variability in the southern <span class="hlt">California</span> <span class="hlt">Current</span> System for the past 2 Kyrs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abella-Gutiérrez, J. L.; Herguera, J. C.</p> <p>2014-12-01</p> <p>San Lázaro Basin (SLB) is a suboxic basin characteristic for its very high sedimentation rates (1mm/yr) and is located in the dynamic southern boundary of the <span class="hlt">California</span> <span class="hlt">Current</span> System (CCS). This southern boundary of the CCS generally extends further south during spring into early summer and retracts towards the north during fall and winter, and this pattern is further amplified or reduced on different time scales, (e.i. interannual timescales by El Niño and La Niña events, or multidecadal ones by the Pacific Decadal Oscillation (PDO)). These oceanographic conditions are related with important differences in the base of the food chain; when the boundary migrates to northern latitudes, the presence of relatively warmer tropical and subtropical waters further stratify the water column, a period when coccolithophorids dominate the microplankton web structure. On the other side, diatoms flourish when the wind-driven circulation expand the subarctic water masses of the CCS to the south and upwelling cells are generated. We find in our cores XRF Ca counts (1 mm resolution) highly correlate with CaCO3 measurements (R=0.56), this last one showing a general decreasing trend over the past 2 Kyrs. The Ca spectrum analysis shows significant peaks for periods centered at 28, 40, 60, 120 yr. The centennial mode of variability of the Ca record shows correlations with Drought area Index from North America. When the variance of this mode is considered, similarities arises with intensity and number of ENSO events from Equatorial archives. Decadal variations of the record are highly correlated (R>0.8) with instrumental measurements of Kaplan sea surface temperature, and the PDO. We will discuss the implications of these periods in the carbonate record and the links between them and other paleoceanographic records in the Pacific.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H24F..04E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H24F..04E"><span id="translatedtitle">Water Management Adaptations for Aquatic <span class="hlt">Ecosystem</span> Services Under a Changing Climate. Analytical Framework and Case Study for Chinook Salmon in <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Escobar, M.; Mosser, C. M.; Thompson, L. C.; Purkey, D.; Moyle, P. B.</p> <p>2010-12-01</p> <p>Spring-run Chinook salmon (Oncorhynchus tshawytscha) are vulnerable to climate change because, before spawning in autumn, adults hold in river pools where temperature increases during summer. As these species naturally experience temperatures close to tolerable thresholds, climate-induced flow and temperature changes can increase their vulnerability. Our objective was to assemble an analytical framework to assess temperature and streamflow thresholds that would lead to critical reductions in spring-run Chinook salmon abundance, and to evaluate management adaptations to ameliorate these impacts. The analytical framework coupled climate data with watershed hydrology and salmon population dynamics models. We used WEAP, an integrated watershed hydrology, water management, and temperature model; and SALMOD, a spatially explicit and size/stage structured model that predicts population dynamics of salmon in freshwater systems. The models simulated weekly mean streamflow, temperature, and salmon abundance in Butte Creek, <span class="hlt">California</span>. We calibrated and validated the models to adequately fit historical data. With the analytical framework built, we used bias-corrected and spatially downscaled climate data from six General Circulation Models and two emission scenarios for the period 2010 - 2099 to run the two linked models, and generated a range of potential future outcomes. WEAP predicted that summer base flows were lower, and water temperatures were higher for climate scenarios vs. historical conditions. SALMOD predicted increased summer thermal mortality of adult salmon; the population was predicted to decline for all climate scenarios and model combinations. We tested management adaptations, including cessation of water diverted for power production, and storage of cold reservoir water upstream for release during hot weather. Some adaptations resulted in cooler temperatures, more adults surviving to spawn, and extended population survival time. The coupled models, together with climate data, constitute a framework able to predict streamflow- and temperature-related mortality of spring-run Chinook salmon, and to evaluate water management adaptations to ameliorate negative climate impacts on fish in <span class="hlt">current</span> or future scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/ofr20131170G','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/ofr20131170G"><span id="translatedtitle">SAFRR tsunami scenario: impacts on <span class="hlt">California</span> <span class="hlt">ecosystems</span>, species, marine natural resources, and fisheries: Chapter G in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Brosnan, Deborah; Wein, Anne; Wilson, Rick</p> <p>2014-01-01</p> <p>We evaluate the effects of the SAFRR Tsunami Scenario on California’s <span class="hlt">ecosystems</span>, species, natural resources, and fisheries. We discuss mitigation and preparedness approaches that can be useful in Tsunami planning. The chapter provides an introduction to the role of <span class="hlt">ecosystems</span> and natural resources in tsunami events (Section 1). A separate section focuses on specific impacts of the SAFRR Tsunami Scenario on California’s <span class="hlt">ecosystems</span> and endangered species (Section 2). A section on commercial fisheries and the fishing fleet (Section 3) documents the plausible effects on California’s commercial fishery resources, fishing fleets, and communities. Sections 2 and 3 each include practical preparedness options for communities and suggestions on information needs or research. Our evaluation indicates that many low-lying coastal habitats, including beaches, marshes and sloughs, rivers and waterways connected to the sea, as well as nearshore submarine habitats will be damaged by the SAFRR Tsunami Scenario. Beach erosion and complex or high volumes of tsunami-generated debris would pose major challenges for ecological communities. Several endangered species and protected areas are at risk. Commercial fisheries and fishing fleets will be affected directly by the tsunami and indirectly by dependencies on infrastructure that is damaged. There is evidence that in some areas intact <span class="hlt">ecosystems</span>, notably sand dunes, will act as natural defenses against the tsunami waves. However, <span class="hlt">ecosystems</span> do not provide blanket protection against tsunami surge. The consequences of ecological and natural resource damage are estimated in the millions of dollars. These costs are driven partly by the loss of <span class="hlt">ecosystem</span> services, as well as cumulative and follow-on impacts where, for example, increased erosion during the tsunami can in turn lead to subsequent damage and loss to coastal properties. Recovery of <span class="hlt">ecosystems</span>, natural resources and fisheries is likely to be lengthy and expensive. Preparedness is key to enhancing resilience to ecological impacts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012NatCC...2..151H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012NatCC...2..151H"><span id="translatedtitle"><span class="hlt">Ecosystem</span> services: Valuing <span class="hlt">ecosystems</span> for climate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hungate, Bruce A.; Hampton, Haydee M.</p> <p>2012-03-01</p> <p><span class="hlt">Ecosystems</span> regulate climate through biogeochemistry and biophysics, but <span class="hlt">current</span> policies only recognize biogeochemical influences. A new proposal to include biophysical effects changes the climate value of <span class="hlt">ecosystems</span>, and sets the stage to expand the suite of climate regulation services considered in global policies and carbon markets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GBioC..29..476W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GBioC..29..476W"><span id="translatedtitle">Predicting long-term carbon sequestration in response to CO2 enrichment: How and why do <span class="hlt">current</span> <span class="hlt">ecosystem</span> models differ?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walker, Anthony P.; Zaehle, Snke; Medlyn, Belinda E.; De Kauwe, Martin G.; Asao, Shinichi; Hickler, Thomas; Parton, William; Ricciuto, Daniel M.; Wang, Ying-Ping; Wrlind, David; Norby, Richard J.</p> <p>2015-04-01</p> <p>Large uncertainty exists in model projections of the land carbon (C) sink response to increasing atmospheric CO2. Free-Air CO2 Enrichment (FACE) experiments lasting a decade or more have investigated <span class="hlt">ecosystem</span> responses to a step change in atmospheric CO2 concentration. To interpret FACE results in the context of gradual increases in atmospheric CO2 over decades to centuries, we used a suite of seven models to simulate the Duke and Oak Ridge FACE experiments extended for 300 years of CO2 enrichment. We also determine key modeling assumptions that drive divergent projections of terrestrial C uptake and evaluate whether these assumptions can be constrained by experimental evidence. All models simulated increased terrestrial C pools resulting from CO2 enrichment, though there was substantial variability in quasi-equilibrium C sequestration and rates of change. In two of two models that assume that plant nitrogen (N) uptake is solely a function of soil N supply, the net primary production response to elevated CO2 became progressively N limited. In four of five models that assume that N uptake is a function of both soil N supply and plant N demand, elevated CO2 led to reduced <span class="hlt">ecosystem</span> N losses and thus progressively relaxed nitrogen limitation. Many allocation assumptions resulted in increased wood allocation relative to leaves and roots which reduced the vegetation turnover rate and increased C sequestration. In addition, self-thinning assumptions had a substantial impact on C sequestration in two models. Accurate representation of N process dynamics (in particular N uptake), allocation, and forest self-thinning is key to minimizing uncertainty in projections of future C sequestration in response to elevated atmospheric CO2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1209197-predicting-long-term-carbon-sequestration-response-co2-enrichment-how-why-do-current-ecosystem-models-differ','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1209197-predicting-long-term-carbon-sequestration-response-co2-enrichment-how-why-do-current-ecosystem-models-differ"><span id="translatedtitle">Predicting long-term carbon sequestration in response to CO2 enrichment: How and why do <span class="hlt">current</span> <span class="hlt">ecosystem</span> models differ?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Walker, Anthony P.; Zaehle, Sönke; Medlyn, Belinda E.; De Kauwe, Martin G.; Asao, Shinichi; Hickler, Thomas; Parton, William; Ricciuto, Daniel M.; Wang, Ying -Ping; Wårlind, David; et al</p> <p>2015-04-27</p> <p>Large uncertainty exists in model projections of the land carbon (C) sink response to increasing atmospheric CO2. Free-Air CO2 Enrichment (FACE) experiments lasting a decade or more have investigated <span class="hlt">ecosystem</span> responses to a step change in atmospheric CO2 concentration. To interpret FACE results in the context of gradual increases in atmospheric CO2 over decades to centuries, we used a suite of seven models to simulate the Duke and Oak Ridge FACE experiments extended for 300 years of CO2 enrichment. We also determine key modeling assumptions that drive divergent projections of terrestrial C uptake and evaluate whether these assumptions can bemore » constrained by experimental evidence. All models simulated increased terrestrial C pools resulting from CO2 enrichment, though there was substantial variability in quasi-equilibrium C sequestration and rates of change. In two of two models that assume that plant nitrogen (N) uptake is solely a function of soil N supply, the net primary production response to elevated CO2 became progressively N limited. In four of five models that assume that N uptake is a function of both soil N supply and plant N demand, elevated CO2 led to reduced <span class="hlt">ecosystem</span> N losses and thus progressively relaxed nitrogen limitation. Many allocation assumptions resulted in increased wood allocation relative to leaves and roots which reduced the vegetation turnover rate and increased C sequestration. Additionally, self-thinning assumptions had a substantial impact on C sequestration in two models. As a result, accurate representation of N process dynamics (in particular N uptake), allocation, and forest self-thinning is key to minimizing uncertainty in projections of future C sequestration in response to elevated atmospheric CO2.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMPP11C1848O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMPP11C1848O"><span id="translatedtitle">Foraminiferal area density as a proxy for ocean acidification over the last 200 years in the <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Osborne, E.; Thunell, R.</p> <p>2013-12-01</p> <p>Anthropogenic activities have resulted in an increase in atmospheric CO2 from 280 ppm to 400 ppm over the last 250 years. It is estimated that approximately one-third of this anthropogenically produced CO2 is sequestered in the global ocean, increasing the inventory of bicarbonate (HCO3-) and hydrogen ions (H+) and consuming carbonate (CO32-) as a result of carbonate buffering reactions. This increase in [H+] lowers seawater pH, the phenomenon known as ocean acidification (OA). Estimates indicate that mean seawater pH has already decreased by 0.1 pH units since 1750 and IPCC reports indicate it is likely that CO2 concentrations will reach 790 ppm by 2100 further reducing pH by 0.3 units. Marine calcifiers, such as foraminifera, utilize CO32- dissolved in seawater during calcification, a process that is highly sensitive to changes in pH due to the chemical reactions described above. The reduction in surface ocean carbonate ion concentration ([CO32-]) caused by OA has impaired calcification of planktonic foraminifera and other marine calcifiers. It has been proposed that planktonic foraminiferal shell weight or shell thickness is positively correlated with ambient [CO32-] and has been used as proxy to reconstruct past changes in the surface ocean carbonate system. An ideal location for the application of this proxy is the <span class="hlt">California</span> <span class="hlt">Current</span> System (CSS), an Eastern Boundary Upwelling System (EBUS), which is characterized as having naturally lower pH. Upwelling introduces CO2-enriched bottom waters to the surface ocean, intensifying the effects of increasing dissolved CO2 as a result of anthropogenic activities. Upwelling produces a wide range of surface water [CO32-] making the Santa Barbara Basin (SBB) an ideal site to carry out a foraminiferal shell weight calibration study. Area density (?A) is a new method for collecting size-normalized shell weights that will be used in this study. Species-specific calibrations have been derived for two symbiont-barren planktonic foraminifera, N. pachyderma (dextral) and G. bulloides. ?A measurements of these species collected from 35 months of sediment trap material are regressed with corresponding calcification depth-specific [CO32-]. Preliminary results show that ?A for both species demonstrate a positive linear relationship with ambient [CO32-]. Seasonal upwelling patterns are clearly recorded in ?A measurements with lower values occurring during periods of peak upwelling, which typically initiates in early spring. Preliminary observations suggest that distinguishing different morphotypes and ontogenic stages of the planktonic foraminifera used in this study could optimize the calibration equations. Final calibration equations will be applied to ?A measurements for a 200-year core record collected near the sediment trap mooring in the SBB. This reconstruction will quantify changes in [CO32-] as a result of OA since the onset of the industrial revolution, providing insights for future reduction in calcification efficiency of foraminifera as a result of OA and increasing carbon emissions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/of/2010/1040/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/of/2010/1040/"><span id="translatedtitle"><span class="hlt">Ecosystem</span> Health in Mineralized Terrane-Data from Podiform Chromite (Chinese Camp Mining District, <span class="hlt">California</span>), Quartz Alunite (Castle Peak and Masonic Mining Districts, Nevada/<span class="hlt">California</span>), and Mo/Cu Porphyry (Battle Mountain Mining District, Nevada) Deposits</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Blecker, Steve W.; Stillings, Lisa L.; Amacher, Michael C.; Ippolito, James A.; DeCrappeo, Nicole M.</p> <p>2010-01-01</p> <p>The myriad definitions of soil/<span class="hlt">ecosystem</span> quality or health are often driven by <span class="hlt">ecosystem</span> and management concerns, and they typically focus on the ability of the soil to provide functions relating to biological productivity and/or environmental quality. A variety of attempts have been made to create indices that quantify the complexities of soil quality and provide a means of evaluating the impact of various natural and anthropogenic disturbances. Though not without their limitations, indices can improve our understanding of the controls behind <span class="hlt">ecosystem</span> processes and allow for the distillation of information to help link scientific and management communities. In terrestrial systems, indices were initially developed and modified for agroecosystems; however, the number of studies implementing such indices in nonagricultural systems is growing. Soil quality indices (SQIs) are typically composed of biological (and sometimes physical and chemical) parameters that attempt to reduce the complexity of a system into a metric of a soil's ability to carry out one or more functions. The indicators utilized in SQIs can be as varied as the studies themselves, reflecting the complexity of the soil and <span class="hlt">ecosystems</span> in which they function. Regardless, effective soil quality indicators should correlate well with soil or <span class="hlt">ecosystem</span> processes, integrate those properties and processes, and be relevant to management practices. Commonly applied biological indicators include measures associated with soil microbial activity or function (for example, carbon and nitrogen mineralization, respiration, microbial biomass, enzyme activity. Cost, accessibility, ease of interpretation, and presence of existing data often dictate indicator selection given the number of available measures. We employed a large number of soil biological, chemical, and physical measures, along with measures of vegetation cover, density, and productivity, in order to test the utility and sensitivity of these measures within various mineralized terranes. We were also interested in examining these relations in the context of determining appropriate reference conditions with which to compare reclamation efforts. The purpose of this report is to present the data used to develop indices of soil and <span class="hlt">ecosystem</span> quality associated with mineralized terranes (areas enriched in metal-bearing minerals), specifically podiform chromite, quartz alunite, and Mo/Cu porphyry systems. Within each of these mineralized terranes, a nearby unmineralized counterpart was chosen for comparison. The data consist of soil biological, chemical, and physical parameters, along with vegetation measurements for each of the sites described below. Synthesis of these data and index development will be the subject of future publications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=economy&pg=5&id=ED515629','ERIC'); return false;" href="http://eric.ed.gov/?q=economy&pg=5&id=ED515629"><span id="translatedtitle"><span class="hlt">California</span> Workforce: <span class="hlt">California</span> Faces a Skills Gap</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Public Policy Institute of California, 2011</p> <p>2011-01-01</p> <p><span class="hlt">California</span>'s education system is not keeping up with the changing demands of the state's economy--soon, <span class="hlt">California</span> will face a shortage of skilled workers. Projections to 2025 suggest that the economy will continue to need more and more highly educated workers, but that the state will not be able to meet that demand. If <span class="hlt">current</span> trends persist,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=market%2bof%2bmedicines%2bdemand&id=ED515629','ERIC'); return false;" href="http://eric.ed.gov/?q=market%2bof%2bmedicines%2bdemand&id=ED515629"><span id="translatedtitle"><span class="hlt">California</span> Workforce: <span class="hlt">California</span> Faces a Skills Gap</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Public Policy Institute of California, 2011</p> <p>2011-01-01</p> <p><span class="hlt">California</span>'s education system is not keeping up with the changing demands of the state's economy--soon, <span class="hlt">California</span> will face a shortage of skilled workers. Projections to 2025 suggest that the economy will continue to need more and more highly educated workers, but that the state will not be able to meet that demand. If <span class="hlt">current</span> trends persist,</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS13H..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS13H..03M"><span id="translatedtitle">Climatic Impacts and resilience of coastal <span class="hlt">ecosystems</span> and fisheries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Micheli, F.</p> <p>2012-12-01</p> <p>Marine and coastal <span class="hlt">ecosystems</span> and human communities around the world are impacted by local anthropogenic pressures and by climate change, resulting in decreased ocean productivity, altered food web dynamics, habitat degradation, economic losses, and health and safety risks as a consequence of the changing and more variable climate. Climatic impacts occur both through altered physical conditions and variability, e.g., seawater temperature and sea level, and through a suite of chemical changes, including ocean acidification and hypoxia. In particular, time series analyses have highlighted declines in dissolved oxygen (DO) concentration in the ocean over the last several decades. In addition to these global trends of decreasing DO, hypoxic conditions have been documented at several coastal locations within productive upwelling-driven <span class="hlt">ecosystems</span>, including the <span class="hlt">California</span> <span class="hlt">Current</span> region, resulting in high mortality of ecologically and commercially important nearshore marine species and significant economic losses. The capacity of local <span class="hlt">ecosystems</span> and associated human communities to adapt to these pressures depends on their resilience, that is the ability of <span class="hlt">ecosystems</span> to absorb disturbance while retaining function and continuing to provide <span class="hlt">ecosystem</span> services, and the ability of people to adapt to change in their environment by altering their behaviors and interactions. I will present global assessments of the cumulative impacts of climatic and local anthropogenic pressures on marine <span class="hlt">ecosystems</span>, and results of interdisciplinary research investigating the <span class="hlt">current</span> impacts of climate change on coastal marine <span class="hlt">ecosystems</span> and human communities of the Pacific coast of Baja <span class="hlt">California</span>, Mexico, and the influences of local and global feedbacks on the resilience and adaptive capacity of these systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1048304','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1048304"><span id="translatedtitle"><span class="hlt">Ecosystem</span> feedbacks to climate change in <span class="hlt">California</span>: Development, testing, and analysis using a coupled regional atmosphere and land-surface model (WRF3-CLM3.5)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Subin, Z.M.; Riley, W.J.; Kueppers, L.M.; Jin, J.; Christianson, D.S.; Torn, M.S.</p> <p>2010-11-01</p> <p>A regional atmosphere model [Weather Research and Forecasting model version 3 (WRF3)] and a land surface model [Community Land Model, version 3.5 (CLM3.5)] were coupled to study the interactions between the atmosphere and possible future <span class="hlt">California</span> land-cover changes. The impact was evaluated on <span class="hlt">California</span>'s climate of changes in natural vegetation under climate change and of intentional afforestation. The ability of WRF3 to simulate <span class="hlt">California</span>'s climate was assessed by comparing simulations by WRF3-CLM3.5 and WRF3-Noah to observations from 1982 to 1991. Using WRF3-CLM3.5, the authors performed six 13-yr experiments using historical and future large-scale climate boundary conditions from the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (GFDL CM2.1). The land-cover scenarios included historical and future natural vegetation from the Mapped Atmosphere-Plant-Soil System-Century 1 (MC1) dynamic vegetation model, in addition to a future 8-million-ha <span class="hlt">California</span> afforestation scenario. Natural vegetation changes alone caused summer daily-mean 2-m air temperature changes of -0.7 to +1 C in regions without persistent snow cover, depending on the location and the type of vegetation change. Vegetation temperature changes were much larger than the 2-m air temperature changes because of the finescale spatial heterogeneity of the imposed vegetation change. Up to 30% of the magnitude of the summer daily-mean 2-m air temperature increase and 70% of the magnitude of the 1600 local time (LT) vegetation temperature increase projected under future climate change were attributable to the climate-driven shift in land cover. The authors projected that afforestation could cause local 0.2-1.2 C reductions in summer daily-mean 2-m air temperature and 2.0-3.7 C reductions in 1600 LT vegetation temperature for snow-free regions, primarily because of increased evapotranspiration. Because some of these temperature changes are of comparable magnitude to those projected under climate change this century, projections of climate and vegetation change in this region need to consider these climate-vegetation interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMIN33E..01F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMIN33E..01F"><span id="translatedtitle">Facilitating Next Generation Science Collaboration: Respecting and Mediating Vocabularies with Semantics in <span class="hlt">Ecosystems</span> Assessments.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fox, P. A.; Maffei, A. R.; Ecoop Team</p> <p>2011-12-01</p> <p>A newly funded initiative is developing and deploying an integrated <span class="hlt">ecosystem</span> assessment (IEA) system using an information science and semantic technologies. The intention is to advance the capacity of an IEA to provide the foundation for synthesis and quantitative analysis of natural and socio-economic <span class="hlt">ecosystem</span> information to support <span class="hlt">ecosystem</span>-based management. In particular, the initiative is create the capacity to assess the impacts of changing climate on two large marine <span class="hlt">ecosystems</span>: the northeast U.S. and the <span class="hlt">California</span> <span class="hlt">Current</span>. These assessments will be essential parts of the science-based decision-support tools used to develop adaptive management measures. Enhanced collaboration is required to achieve these goals: interaction and information sharing within and among diverse data providers, analysis tool developers and user groups that constitute the broader coastal and marine <span class="hlt">ecosystem</span> science application community. This presentation indicates how semantic solutions are fundamental to this initiative.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMNH24A..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMNH24A..02B"><span id="translatedtitle"><span class="hlt">Current</span> progress in using multiple electromagnetic indicators to determine location, time, and magnitude of earthquakes in <span class="hlt">California</span> and Peru (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bleier, T. E.; Dunson, C.; Roth, S.; Heraud, J.; Freund, F. T.; Dahlgren, R.; Bryant, N.; Bambery, R.; Lira, A.</p> <p>2010-12-01</p> <p>Since ultra-low frequency (ULF) magnetic anomalies were discovered prior to the 1989 Loma Prieta, Ca. M7.0 earthquake, QuakeFinder, a small R&D group based in Palo Alto <span class="hlt">California</span> has systematically monitored ULF magnetic signals with a network of 3-axis induction magnetometers since 2000 in <span class="hlt">California</span>. This raw magnetometer data was collected at 20-50 samples per sec., with no preprocessing, in an attempt to collect an accurate time history of electromagnetic waveforms prior to, during, and after large earthquakes within 30 km. of these sensors. Finally in October 2007, the QuakeFinder team observed a series of strange magnetic pulsations at the Alum Rock, <span class="hlt">California</span> site, 14 days prior to M5.4 earthquake. These magnetic signals observed were relatively short, random pulsations, not continuous waveform signals like Pc1 or Pc3 micropulsations. The magnetic pulses have a characteristic uni-polar shapes and 0.5 sec. to 30 sec. durations, much longer than lightning signals. In May of 2010, very similar pulses were observed at Tacna, Peru, 13 days prior to a M6.2 earthquake, using a QuakeFinder station jointly operated under collaboration with the Catholic University in Lima Peru (PUCP). More examples of these pulsations were sought, and a historical review of older <span class="hlt">California</span> magnetic data discovered fewer but similar pulsations occurred at the Hollister, Ca. site operated by UC Berkeley (e.g. San Juan Bautista M5.1 earthquake on August 12, 1998). Further analysis of the direction of arrival of the magnetic pulses showed an interesting “azimuth clustering” observed in both Alum Rock, Ca. and Tacna, Peru data. The complete time series of the Alum Rock data allowed the team to analyze subsequent changes observed in magnetometer “filter banks” (0.001 Hz to 10 Hz filter bands, similar to those used by Fraser-Smith in 1989), but this time using time-adjusted limits based on time of day, time of year, Kp, and site background noise. These site-customized limits showed similar increases in 30 minute averaged energy excursions, but the 30 minute averages had a disadvantage in that they reduced the signal to noise ratio over the individual pulse counting method. In other electromagnetic monitoring methods, air conductivity instrumentation showed major changes in positive air-borne ions observed near the Alum Rock and Tacna sites, peaking during the 24 hours prior to the earthquake. The use of GOES (geosynchronous) satellite infra red (IR) data showed that an unusual apparent “night time heating” occurred in an extended area within 40+ km. of the Alum Rock site, and this IR signature peaked around the time of the magnetic pulse count peak. The combination of these 3 indicators (magnetic pulse counts, air conductivity, and IR night time heating) may be the start in determining the time (within 1-2 weeks), location (within 20-40km) and magnitude (within +/- 1 increment of Richter magnitude) of earthquake greater than M5.4</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=32974&keyword=lugo&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=49478049&CFTOKEN=29128973','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=32974&keyword=lugo&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=49478049&CFTOKEN=29128973"><span id="translatedtitle">CARBON DIOXIDE SEQUESTRATION IN TERRESTRIAL <span class="hlt">ECOSYSTEMS</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The terrestrial biosphere plays a prominent role in the global carbon (C) cycle. errestrial <span class="hlt">ecosystems</span> are <span class="hlt">currently</span> accumulating C and it appears feasible to manage existing terrestrial (forest, agronomic, desert) <span class="hlt">ecosystems</span> to maintain or increase C storage. orest <span class="hlt">ecosystems</span> ca...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17591729','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17591729"><span id="translatedtitle"><span class="hlt">Current</span> status of the greenhouse whitefly, Trialeurodes vaporariorum, susceptibility to neonicotinoid and conventional insecticides on strawberries in southern <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bi, Jian L; Toscano, Nick C</p> <p>2007-08-01</p> <p>Since 1998, the greenhouse whitefly, Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae), has emerged as a major insect pest of many horticultural crops in coastal <span class="hlt">California</span>. Control of this pest has been heavily dependent upon chemical insecticides. Objectives of this study were to determine the status of the greenhouse whitefly susceptibility to neonicotinoid and conventional insecticides on strawberries in Oxnard/Ventura, a year-round intensive horticultural production area of southern <span class="hlt">California</span>. For bioassay tests, adult whiteflies were collected from commercial strawberry crops, and immatures were directly developed from eggs laid by these adults. LD(50) values of soil-applied imidacloprid, thiamethoxam and dinotefuran were respectively 8.7, 3.2 and 4.9 times higher for the adults, 1.8, 1.2 and 1.5 times higher for the first-instar nymphs and 89.4, 390 and 10.4 times higher for the third-instar nymphs than their top label rates. LC(50) values of foliar-applied imidacloprid, thiamethoxam and acetamiprid were respectively 6.1, 6.0 and 1.7 times higher for the adults and 3.8, 8.7 and 4.4 times higher for the second-instar nymphs than their top label rates. For the adults, LC(90) values of endosulfan, malathion, methomyl, bifenthrin and fenpropathrin were 2.2, 1.2, 1.9, 2.3 and 4.9 times lower than their respective top label rates. Chlorpyrifos was not very effective against the adults, as indicated by its LC(90) being 120% higher than its top label rate. The present results strongly emphasize the need to develop resistance management strategies in the region. PMID:17591729</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DSRII.112...61J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DSRII.112...61J"><span id="translatedtitle">Trapped diurnal internal tides, propagating semidiurnal internal tides, and mixing estimates in the <span class="hlt">California</span> <span class="hlt">Current</span> System from sustained glider observations, 2006-2012</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnston, T. M. Shaun; Rudnick, Daniel L.</p> <p>2015-02-01</p> <p>From 2006-2012, along 3 repeated cross-shore transects (<span class="hlt">California</span> Cooperative Oceanic Fisheries Investigations lines 66.7, 80, and 90) in the <span class="hlt">California</span> <span class="hlt">Current</span> System, 33 609 shear and 39 737 strain profiles from 66 glider missions are used to estimate mixing via finescale parameterizations from a dataset containing over 52 000 profiles. Elevated diffusivity estimates and energetic diurnal (D1) and semidiurnal (D2) internal tides are found: (a) within 100 km of the coast on lines 66.7 and 80 and (b) over the Santa Rosa-Cortes Ridge (SRCR) in the Southern <span class="hlt">California</span> Bight (SCB) on line 90. While finding elevated mixing near topography and associated with internal tides is not novel, the combination of resolution and extent in this ongoing data collection is unmatched in the coastal ocean to our knowledge. Both D1 and D2 internal tides are energy sources for mixing. At these latitudes, the D1 internal tide is subinertial. On line 90, D1 and D2 tides are equally energetic over the SRCR, the main site of elevated mixing within the SCB. Numerous sources of internal tides at the rough topography in the SCB produce standing and/or partially-standing waves. On lines 66.7 and 80, the dominant energy source below about 100 m for mixing is the D1 internal tide, which has an energy density of the D2 internal tide. On line 80, estimated diffusivity, estimated dissipation, and D1 energy density peak in summer. The D1 energy density shows an increasing trend from 2006 to 2012. Its amplitude and phase are mostly consistent with topographically-trapped D1 internal tides traveling with the topography on their right. The observed offshore decay of the diffusivity estimates is consistent with the exponential decay of a trapped wave with a mode-1 Rossby radius of 20-30 km. Despite the variable mesoscale, it is remarkable that coherent internal tidal phase is found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003GeoRL..30.1896P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003GeoRL..30.1896P"><span id="translatedtitle">A new climate regime in northeast pacific <span class="hlt">ecosystems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peterson, William T.; Schwing, Franklin B.</p> <p>2003-09-01</p> <p>Following a strong El Nio, the climate of the North Pacific underwent a rapid and striking transition in late 1998. Upwelling-favorable winds strengthened over the <span class="hlt">California</span> <span class="hlt">Current</span> (CC), and winds weakened in the Gulf of Alaska (GOA). Coastal waters of the CC and GOA cooled by several degrees, and the Pacific Decadal Oscillation (PDO) reversed sign and remained negative through summer 2002. Zooplankton biomass in the northern CC doubled and switched from warm to cold water species dominance, coho and chinook salmon stocks rebounded, and anchovy and osmeriids increased. Persistent changes in atmosphere and upper ocean fields and <span class="hlt">ecosystem</span> structure suggest a climate regime shift has occurred, similar (opposite) to shifts observed in 1947 (1925 and 1976). If the 1998 regime shift in the northern CC is completely analogous to earlier shifts, then <span class="hlt">ecosystem</span> structure should have changed in the GOA. Recent surveys indicate this <span class="hlt">ecosystem</span> has transformed as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6201581','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6201581"><span id="translatedtitle">Variability in biomass yields of large marine <span class="hlt">ecosystems</span> (LMEs) during climate change</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sherman, K. )</p> <p>1993-06-01</p> <p>Results of <span class="hlt">ecosystem</span> studies relating to variations in biomass yields are examined in relation to principle driving forces including climate change, coastal pollution, habitat degradation, and overexploitation of living marine resources. Among the <span class="hlt">ecosystems</span> compared with regard to the different prime driving forces, affecting sustainability of biomass yields, are the Black Sea, the Baltic Sea, the Barents Sea, Kuroshio <span class="hlt">Current</span>, <span class="hlt">California</span> <span class="hlt">Current</span>, Great Barrier Reef, Gulf of Mexico, Yellow Sea, Icelandic Shelf, and Northeast US Shelf <span class="hlt">ecosystems</span>. The designation and management of large marine <span class="hlt">ecosystems</span> (LMEs) is, at present, an evolving scientific and geopolitical process. Sufficient progress has been made to allow for useful comparisons among different processes influencing large-scale changes in the biomass yields of LMEs. The most severely impacted LMEs are off the coasts of the continents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H51D0854C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H51D0854C"><span id="translatedtitle">Effects of Recent Debris Flows on Stream <span class="hlt">Ecosystems</span> and Food Webs in Small Watersheds in the Central Klamath Mountains, NW <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cover, M. R.; de La Fuente, J.</p> <p>2008-12-01</p> <p>Debris flows are common erosional processes in steep mountain areas throughout the world, but little is known about the long-term ecological effects of debris flows on stream <span class="hlt">ecosystems</span>. Based on debris flow histories that were developed for each of ten tributary basins, we classified channels as having experienced recent (1997) or older (pre-1997) debris flows. Of the streams classified as older debris flow streams, three streams experienced debris flows during floods in 1964 or 1974, while two streams showed little or no evidence of debris flow activity in the 20th century. White alder (Alnus rhombifolia) was the dominant pioneer tree species in recent debris flow streams, forming localized dense patches of canopy cover. Maximum temperatures and daily temperature ranges were significantly higher in recent debris flow streams than in older debris flow streams. Debris flows resulted in a shift in food webs from allochthonous to autochthonous energy sources. Primary productivity, as measured by oxygen change during the day, was greater in recent debris flow streams, resulting in increased abundances of grazers such as the armored caddisfly Glossosoma spp. Detritivorous stoneflies were virtually absent in recent debris flow streams because of the lack of year-round, diverse sources of leaf litter. Rainbow trout (Oncorhynchus mykiss) were abundant in four of the recent debris flow streams. Poor recolonizers, such as the Pacific giant salamander (Dicamptodon tenebrosus), coastal tailed frog (Ascaphus truei), and signal crayfish (Pacifistacus leniusculus), were virtually absent in recent debris flow streams. Forest and watershed managers should consider the role of forest disturbances, such as road networks, on debris flow frequency and intensity, and the resulting ecological effects on stream <span class="hlt">ecosystems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/925916','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/925916"><span id="translatedtitle">Chemical Speciation of Sulfur in Marine Cloud Droplets and Particles: Analysis of Individual Particles from Marine Boundary Layer over the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>William R. Wiley Environmental Sciences Laboratory, Pacific Northwest National Laboratory; Gilles, Mary K; Hopkins, Rebecca J.; Desyaterik, Yury; Tivanski, Alexei V.; Zaveri, Rahul A.; Berkowitz, Carl M.; Tyliszczak, Tolek; Gilles, Mary K.; Laskin, Alexander</p> <p>2008-03-12</p> <p>Detailed chemical speciation of the dry residue particles from individual cloud droplets and interstitial aerosol collected during the Marine Stratus Experiment (MASE) was performed using a combination of complementary microanalysis techniques. Techniques include computer controlled scanning electron microscopy with energy dispersed analysis of X-rays (CCSEM/EDX), time-of-flight secondary ionization mass spectrometry (TOF-SIMS), and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Samples were collected at the ground site located in Point Reyes National Seashore, approximately 1 km from the coast. This manuscript focuses on the analysis of individual particles sampled from air masses that originated over the open ocean and then passed through the area of the <span class="hlt">California</span> <span class="hlt">current</span> located along the northern <span class="hlt">California</span> coast. Based on composition, morphology, and chemical bonding information, two externally mixed, distinct classes of sulfur containing particles were identified: chemically modified (aged) sea salt particles and secondary formed sulfate particles. The results indicate substantial heterogeneous replacement of chloride by methanesulfonate (CH3SO3-) and non-sea salt sulfate (nss-SO42-) in sea-salt particles with characteristic ratios of nss-S/Na>0.10 and CH3SO3-/nss-SO42->0.6.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70012809','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70012809"><span id="translatedtitle">COMPARISON OF RECORDING <span class="hlt">CURRENT</span> METERS USED FOR MEASURING VELOCITIES IN SHALLOW WATERS OF SAN FRANCISCO BAY, <span class="hlt">CALIFORNIA</span>.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gartner, Jeffrey W.; Oltmann, Richard N.</p> <p>1985-01-01</p> <p>The authors determine the feasibility of collecting reliable <span class="hlt">current</span>-meter data in shallow water under natural conditions. The study involved field testing four types of recording <span class="hlt">current</span> meters (different speed sensors) and comparing data recorded by the meters under different field conditions. Speeds recorded by the <span class="hlt">current</span> meters at slack water and during maximum flows were compared during calm and windy conditions at various tide levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22527455','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22527455"><span id="translatedtitle">Comparative bioaccumulation of trace metals using six filter feeder organisms in a coastal lagoon <span class="hlt">ecosystem</span> (of the central-east Gulf of <span class="hlt">California</span>).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jara-Marini, M E; Tapia-Alcaraz, J N; Dumer-Gutirrez, J A; Garca-Rico, L; Garca-Hernndez, J; Pez-Osuna, F</p> <p>2013-02-01</p> <p>The Tobari Lagoon, located in the central-east coast of the Gulf of <span class="hlt">California</span>, receives effluents from the Yaqui Valley, one of the most extensive agricultural areas of Mxico. The Tobari Lagoon also receives effluents from nearby shrimp farms and untreated municipal sewage. Surface sediment samples and six different species of filter feeders (Crassostrea corteziensis, Crassostrea gigas, Chione gnidia, Anadara tuberculosa, Chione fluctifraga, and Fistulobalanus dentivarians) were collected during the dry and the rainy seasons and analyzed to determine concentrations of cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn). Seasonal variations in metal concentrations in sediment were evident, especially for Cd, Cu, Hg, and Zn. The total and bioavailable concentrations of the five metals are not elevated in comparison to other areas around the world. The percentages of bioavailable respect to total concentrations of the metals varied from 0.6 % in Hg to 50.2 % for Cu. In the organisms, Hg showed the lowest concentrations (ranged from 0.22 to 0.65 ?g/g) while Zn showed the highest (ranged from 36.6 to 1,702 ?g/g). Linear correlations between the levels of Cu, Pb, and Zn in the soft tissues of C. fluctifraga and C. gnidia, and A. tuberculosa and C. gnidia were found. Seasonal and interspecies variations in the metal levels in filter feeders were found; F. dentivarians, C. corteziensis, and C. gigas exhibited the highest levels, could be used as biomonitors of metals contamination in this area. PMID:22527455</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/sir/2008/5094/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/sir/2008/5094/"><span id="translatedtitle">Connections Among the Spatial and Temporal Structures in Tidal <span class="hlt">Currents</span>, Internal Bores, and Surficial Sediment Distributions Over the Shelf off Palos Verdes, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Noble, Marlene A.; Rosenberger, Kurt J.; Xu, Jingping; Signell, Richard P.; Steele, Alex</p> <p>2009-01-01</p> <p>The topography of the Continental Shelf in the central portion of the Southern <span class="hlt">California</span> Bight has rapid variations over relatively small spatial scales. The width of the shelf off the Palos Verdes peninsula, just northwest of Los Angeles, <span class="hlt">California</span>, is only 1 to 3 km. About 7 km southeast of the peninsula, the shelf within San Pedro Bay widens to about 20 km. In 2000, the Los Angeles County Sanitation District began deploying a dense array of moorings in this complex region of the central Southern <span class="hlt">California</span> Bight to monitor local circulation patterns. Moorings were deployed at 13 sites on the Palos Verdes shelf and within the northwestern portion of San Pedro Bay. At each site, a mooring supported a string of thermistors and an adjacent bottom platform housed an Acoustic Doppler <span class="hlt">Current</span> Profiler. These instruments collected vertical profiles of <span class="hlt">current</span> and temperature data continuously for one to two years. The variable bathymetry in the region causes rapid changes in the amplitudes and spatial structures of barotropic tidal <span class="hlt">currents</span>, internal tidal <span class="hlt">currents</span>, and in the associated nonlinear baroclinic <span class="hlt">currents</span> that occur at approximate tidal frequencies. The largest barotropic tidal constituent is M2, the principal semidiurnal tide. The amplitude of this tidal <span class="hlt">current</span> changes over fairly short along-shelf length scales. Tidal-<span class="hlt">current</span> amplitudes are largest in the transition region between the two shelves; they increase from about 5 cm/s over the northern San Pedro shelf to nearly 10 cm/s on the southern portion of the Palos Verdes Shelf. Tidal-<span class="hlt">current</span> amplitudes are then reduced to less than 2 cm/s over the very narrow section of the northern Palos Verdes shelf that lies just 6 km upcoast of the southern sites. Models suggest that the amplitude of the barotropic M2 tidal <span class="hlt">currents</span>, which propagate toward the northwest primarily as a Kelvin wave, is adjusting to the short topographic length scales in the region. Semidiurnal sea-level oscillations are, as expected, independent of these topographic variations; they have a uniform amplitude and phase structure over the entire region. Because the cross-shelf angle of the seabed over most of the Palos Verdes shelf is 1 to 3 degrees, which is critical for the local generation and/or enhancement of nonlinear characteristics in semidiurnal internal tides, some internal tidal-<span class="hlt">current</span> events have strong asymmetric <span class="hlt">current</span> oscillations that are enhanced near the seabed. Near-bottom <span class="hlt">currents</span> in these events are directed primarily offshore with amplitudes that exceed 30 cm/s. The spatial patterns in these energetic near-bottom <span class="hlt">currents</span> have fairly short-length scales. They are largest over the inner shelf and in the transition region between the Palos Verdes and San Pedro shelves. This spatial pattern is similar to that found in the barotropic tidal <span class="hlt">currents</span>. Because these baroclinic <span class="hlt">currents</span> have an approximate tidal frequency, an asymmetric vertical structure, and a somewhat stable phase, they can produce a non-zero depth-mean flow for periods of a few months. These baroclinic <span class="hlt">currents</span> can interact with the barotropic tidal <span class="hlt">current</span> and cause an apparent increase (or decrease) in the estimated barotropic tidal-<span class="hlt">current</span> amplitude. The apparent amplitude of the barotropic tidal <span class="hlt">current</span> may change by 30 to 80 percent or more in a <span class="hlt">current</span> record that is less than three months long. The <span class="hlt">currents</span> and surficial sediments in this region are in dynamic equilibrium in that the spatial patterns in bottom stresses generated by near-bed <span class="hlt">currents</span> from surface tides, internal tides, and internal bores partly control the spatial patterns in the local sediments. Coarser sediments are found in the regions with enhanced bottom stresses (that is, over the inner shelf and in the region between the Palos Verdes and San Pedro shelves). Finer sediments are found over the northwestern portion of the Palos Verdes shelf, where near-bottom <span class="hlt">currents</span> are relatively weak. The nonlinear asymmetries in the i</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PrOce..77..127T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PrOce..77..127T"><span id="translatedtitle">The late 1980s regime shift in the <span class="hlt">ecosystem</span> of Tsushima warm <span class="hlt">current</span> in the Japan/East Sea: Evidence from historical data and possible mechanisms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tian, Yongjun; Kidokoro, Hideaki; Watanabe, Tatsuro; Iguchi, Naoki</p> <p>2008-05-01</p> <p>A climatic regime shift, an abrupt change from cooling to warming in the Japan/East Sea (JES), particularly in the Tsushima warm <span class="hlt">current</span> (TWC) region, occurred in the late 1980s. The <span class="hlt">ecosystem</span> of the JES responded strongly to the changing thermal regime. Many, but not all biological components of the <span class="hlt">ecosystem</span>, spanning from plankton to predatory fishes, and including both warm-water pelagic and cold-water demersal species responded to this late 1980s climatic regime shift in the JES. Diatom abundance (cell number) in spring from a monitoring line located in the central part of JES showed decadal variations with a step change from positive to negative anomalies in 1991. Zooplankton biomass in spring and autumn was high in the 1970s, declined during the 1980s, and returned to higher, but quite variable levels during the 1990s. Japanese sardine catch increased after 1974 to its peak level in 1989 and then declined dramatically to 1974 levels by 1997 with step changes in 1979 and 1994. Conversely, catches of other small pelagic species such as Japanese anchovy and common squid, and several higher-trophic fishes, such as yellowtail and tunas increased markedly in the 1990s compared to the early-mid 1980s. Step changes were detected in these pelagic species during 1989-1992. Catch of demersal species (crab, pink shrimp, Pacific cod and walleye pollock) were high during most of the 1970-1980s, but declined at various times in the late 1980s to generally low catches in the 1990s. Detailed analysis of the demersal fish assemblage composition, abundance and distribution indicated a shift in the late 1980s with several years lag in the time of change. Cold-water species (e.g., walleye pollock, Pacific cod) decreased in abundance and the regions in which their abundances remained high became greatly reduced in extent. Conversely, warm-water species (e.g., pointhead flounder, shotted halibut) increased in abundance and/or extended their spatial range (as indicated by trawl catch) during the warm 1990s. A principal component analysis for pelagic and demersal fish assemblages, suggested decadal variation patterns with a step change during 1986-1988. Abundance changes were identified not only in the plankton, but also in small pelagic fishes, and in predatory fishes. These changes were reflected in fish community indicators, and suggest an <span class="hlt">ecosystem</span> regime shift occurred in the TWC region as a result of the late 1980s climatic regime shift. A hypothesis on the ecological response process to the late 1980s climatic regime shift was proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PrOce.137..299A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PrOce.137..299A"><span id="translatedtitle">Diet diversity of jack and chub mackerels and <span class="hlt">ecosystem</span> changes in the northern Humboldt <span class="hlt">Current</span> system: A long-term study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alegre, Ana; Bertrand, Arnaud; Espino, Marco; Espinoza, Pepe; Dioses, Teobaldo; Ñiquen, Miguel; Navarro, Iván; Simier, Monique; Ménard, Frédéric</p> <p>2015-09-01</p> <p>Jack mackerel Trachurus murphyi (JM) and chub mackerel Scomber japonicus (CM) are medium size pelagic fish predators and highly exploited resources. Here we investigated the spatiotemporal patterns of JM and CM diet composition using a large dataset of stomach samples collected from 1973 to 2013 along the Peruvian coast. In total 47,535 stomachs (18,377 CM and 29,158 JM) were analysed, of which 23,570 (12,476 CM and 11,094 JM) were non-empty. Results show that both species are opportunistic and present a trophic overlap. However, despite their smaller maximal size, CM consumed more fish than JM. Both diets presented high spatiotemporal variability. Spatially, the shelf break appears as a strong biogeographical barrier affecting prey species distribution and thus CM and JM diet. Opportunistic foragers are often considered as actual indicators of <span class="hlt">ecosystem</span> changes; we show here that diet composition of CM and JM reveal <span class="hlt">ecosystem</span> changes but is not always a good indicator of changes in prey biomass as prey accessibility and energy content can also play an important role. In addition we found that El Niño events have a surprisingly weak effect on stomach fullness and diet. Finally our results show that the classic paradigm of positive correlation between diversity and temperature is unlikely to occur in the Humboldt <span class="hlt">Current</span> system where productivity seems to be the main driver. We show how energy content of forage species and the strength of the oxygen minimum zone most likely play an important role prey diversity and accessibility, and thus in fish foraging behaviour.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987EOSTr..68....1C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987EOSTr..68....1C"><span id="translatedtitle">The Central <span class="hlt">California</span> Coastal Circulation Study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chelton, Dudley B.; Bernstein, Robert L.; Bratkovich, Alan; Kosro, P. Michael</p> <p></p> <p>The Central <span class="hlt">California</span> Coastal Circulation Study (CCCCS) was an 18-month field program designed to study the variability of water mass characteristics and the velocity field on the continental shelf and upper continental slope of <span class="hlt">California</span> from Point Conception to San Francisco. This study was funded by the U.S. Department of Interior, Minerals Management Service (MMS), as part of an overall assessment of the impact of development of oil and gas resources on the <span class="hlt">ecosystem</span> of coastal <span class="hlt">California</span>. The Santa Maria Basin area, which extends from Point Conception to Point Buchon (100 km to the north) and about 50 km offshore, is of particular interest, as this area will be the focus of oil and gas exploration and production over the next decade. However, MMS is also interested in how the ocean variability in this region relates to the large-scale flow of the <span class="hlt">California</span> <span class="hlt">Current</span> System. The field work for CCCCS was conducted from February 1984 through July 1985 by Raytheon Service Company. This paper summarizes some of the preliminary results from analysis of the CCCCS data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19731261','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19731261"><span id="translatedtitle">The integrated control concept and its relevance to <span class="hlt">current</span> integrated pest management in <span class="hlt">California</span> fresh market grapes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bentley, Walter J</p> <p>2009-12-01</p> <p>The foundation of an integrated pest management program involves valid treatment thresholds, accurate and simple monitoring methods, effective natural controls, selective pesticides and trained individuals who can implement the concept. The Integrated Control Concept written by Stern, Smith, van den Bosch and Hagen elucidated each of these points in an alfalfa <span class="hlt">ecosystem</span>. Alfalfa hay (Medicago sativa L.) has a low per acre value, requires little hand labor and is primarily marketed in the USA. In contrast, fresh market table grape (Vitis vinifera L.) has a high per acre value, requires frequent hand labor operations, suffers unacceptable cosmetic damage and is marketed throughout both the USA and the world. Each of the components of a working IPM program is present in table grape production. Marketing grapes to foreign countries presents special problems with pests considered invasive and where residue tolerances for some selective insecticides are lacking. However, fresh market grape farmers are still able to deal with these special problems and utilize an IPM program that has resulted in a 42% reduction in broad-spectrum insecticide use from 1995 to 2007. PMID:19731261</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25103902','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25103902"><span id="translatedtitle">Persistent organic pollutants in forage fish prey of rhinoceros auklets breeding in Puget Sound and the northern <span class="hlt">California</span> <span class="hlt">Current</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Good, Thomas P; Pearson, Scott F; Hodum, Peter; Boyd, Daryle; Anulacion, Bernadita F; Ylitalo, Gina M</p> <p>2014-09-15</p> <p>Organochlorine contaminants in upper trophic-level consumers inhabiting Puget Sound are consistently higher than in those species inhabiting other west coast locations. We analyzed persistent organic pollutants (POPs) in the six most common fish prey of rhinoceros auklets breeding on Protection Island (Puget Sound), Tatoosh Island (WA coast), and Destruction Island (WA coast). Wet-weight concentrations of POPs ranged widely (PCBs: 1.6-25.0 ng/g; DDTs: 0.2-56.0 ng/g; PBDEs:<LOQ-49.0 ng/g), but overall patterns showed fish from Puget Sound were 2-4 times more contaminated and had similar contaminant profiles compared to fish from the outer coast. Unexpectedly elevated PCB and PBDE concentrations in Chinook salmon from the outer coast likely reflected Columbia River. Calculating contaminant loads for auklet nestlings magnified differences observed between inland and outer coast fish prey. Monitoring of breeding auklets, their prey and other resident marine birds is needed to assess biomagnification impacts in the Puget Sound marine <span class="hlt">ecosystem</span>. PMID:25103902</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PrOce..91...74M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PrOce..91...74M"><span id="translatedtitle">The Regional Ocean Modeling System (ROMS) 4-dimensional variational data assimilation systems . Part III - Observation impact and observation sensitivity in the <span class="hlt">California</span> <span class="hlt">Current</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, Andrew M.; Arango, Hernan G.; Broquet, Gregoire; Edwards, Chris; Veneziani, Milena; Powell, Brian; Foley, Dave; Doyle, James D.; Costa, Dan; Robinson, Patrick</p> <p>2011-10-01</p> <p>The critical role played by observations during ocean data assimilation was explored when the Regional Ocean Modeling System (ROMS) 4-dimensional variational (4D-Var) data assimilation system was applied sequentially to the <span class="hlt">California</span> <span class="hlt">Current</span> circulation. The adjoint of the 4D-Var gain matrix was used to quantify the impact of individual observations and observation platforms on different aspects of the 4D-Var circulation estimates during both analysis and subsequent forecast cycles. In this study we focus on the alongshore and cross-shore transport of the <span class="hlt">California</span> <span class="hlt">Current</span> System associated with wind-induced coastal upwelling along the central <span class="hlt">California</span> coast. The majority of the observations available during any given analysis cycle are from satellite platforms in the form of SST and SSH, and on average these data exert the largest controlling influence on the analysis increments and forecast skill of coastal transport. However, subsurface in situ observations from Argo floats, CTDs, XBTs and tagged marine mammals often have a considerable impact on analyses and forecasts of coastal transport, even though these observations represent a relatively small fraction of the available data at any particular time. During 4D-Var the observations are used to correct for uncertainties in the model control variables, namely the initial conditions, surface forcing, and open boundary conditions. It is found that correcting for uncertainties in both the initial conditions and surface forcing has the largest impact on the analysis increments in alongshore transport, while the cross-shore transport is controlled mainly by the surface forcing. The memory of the circulation associated with the control variable increments was also explored in relation to 7 day forecasts of the coastal circulation. Despite the importance of correcting for surface forcing uncertainties during analysis cycles, the coastal transport during forecast cycles initialized from the analyses has less memory of the surface forcing corrections, and is controlled primarily by the analysis initial conditions. Using the adjoint of the entire 4D-Var system we have also explored the sensitivity of the coastal transport to changes in the observations and the observation array. A single integration of the adjoint of 4D-Var can be used to predict the change that occurs when observations from different platforms are omitted from the 4D-Var analysis. Thus observing system experiments can be performed for each data assimilation cycle at a fraction of the computational cost that would be required to repeat the 4D-Var analyses when observations are withheld. This is the third part of a three part series describing the ROMS 4D-Var systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/sir/2009/5264/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/sir/2009/5264/"><span id="translatedtitle">Field Surveys of Rare Plants on Santa Cruz Island, <span class="hlt">California</span>, 2003-2006: Historical Records and <span class="hlt">Current</span> Distributions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McEachern, A. Kathryn; Chess, Katherine A.; Niessen, Ken</p> <p>2010-01-01</p> <p>Santa Cruz Island is the largest of the northern Channel Islands located off the coast of <span class="hlt">California</span>. It is owned and managed as a conservation reserve by The Nature Conservancy and the Channel Islands National Park. The island is home to nine plant taxa listed in 1997 as threatened or endangered under the federal Endangered Species Act, because of declines related to nearly 150 years of ranching on the island. Feral livestock were removed from the island as a major conservation step, which was part of a program completed in early 2007 with the eradication of pigs and turkeys. For the first time in more than a century, the rare plants of Santa Cruz Island have a chance to recover in the wild. This study provides survey information and living plant materials needed for recovery management of the listed taxa. We developed a database containing information about historical collections of the nine taxa and used it to plan a survey strategy. Our objectives were to relocate as many of the previously known populations as possible, with emphasis on documenting sites not visited in several decades, sites that were poorly documented in the historical record, and sites spanning the range of environmental conditions inhabited by the taxa. From 2003 through 2006, we searched for and found 39 populations of the taxa, indicating that nearly 80 percent of the populations known earlier in the 1900s still existed. Most populations are small and isolated, occupying native-dominated habitat patches in a highly fragmented and invaded landscape; they are still at risk of declining through population losses. Most are not expanding beyond the edges of their habitat patches. However, most taxa appeared to have good seed production and a range of size classes in populations, indicating a good capacity for plant recruitment and population growth in these restricted sites. For these taxa, seed collection and outplanting might be a good strategy to increase numbers of populations for species recovery. Several taxa have particular problems evidenced by lack of fruit set, very small population sizes, or unstable habitats. We collected seeds of all but two taxa for seed banking, and live cuttings of two clonal shrubs for cultivation at the Santa Barbara Botanic Garden. The survey data, seeds and cuttings provide a baseline and a foundation for planning, conducting, and tracking recovery of the nine federally listed plant taxa of Santa Cruz Island.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/sim3306','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/sim3306"><span id="translatedtitle"><span class="hlt">California</span> State Waters Map Series: offshore of San Gregorio, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cochrane, Guy R.; Dartnell, Peter; Greene, H. Gary; Watt, Janet T.; Golden, Nadine E.; Endris, Charles A.; Phillips, Eleyne L.; Hartwell, Stephen R.; Johnson, Samuel Y.; Kvitek, Rikk G.; Erdey, Mercedes D.; Bretz, Carrie K.; Manson, Michael W.; Sliter, Ray W.; Ross, Stephanie L.; Dieter, Bryan E.; Chin, John L.; Cochran, Susan A.</p> <p>2014-01-01</p> <p>In 2007, the <span class="hlt">California</span> Ocean Protection Council initiated the <span class="hlt">California</span> Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of <span class="hlt">California</span>'s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. The Offshore of San Gregorio map area is located in northern <span class="hlt">California</span>, on the Pacific coast of the San Francisco Peninsula about 50 kilometers south of the Golden Gate. The map area lies offshore of the Santa Cruz Mountains, part of the northwest-trending Coast Ranges that run roughly parallel to the San Andreas Fault Zone. The Santa Cruz Mountains lie between the San Andreas Fault Zone and the San Gregorio Fault system. The nearest significant onshore cultural centers in the map area are San Gregorio and Pescadero, both unincorporated communities with populations well under 1,000. Both communities are situated inland of state beaches that share their names. No harbor facilities are within the Offshore of San Gregorio map area. The hilly coastal area is virtually undeveloped grazing land for sheep and cattle. The coastal geomorphology is controlled by late Pleistocene and Holocene slip in the San Gregorio Fault system. A westward bend in the San Andreas Fault Zone, southeast of the map area, coupled with right-lateral movement along the San Gregorio Fault system have caused regional folding and uplift. The coastal area consists of high coastal bluffs and vertical sea cliffs. Coastal promontories in the northern and southern parts of the map area are the result of right-lateral motion on strands of the San Gregorio Fault system. In the south, headlands near Pescadero Point have been uplifted by motion along the west strand of the San Gregorio Fault (also called the Frijoles Fault), which separates rocks of the Pigeon Point Formation south of the fault from rocks of the Purisima Formation north of the fault. The regional uplift in this map area has caused relatively shallow water depths within <span class="hlt">California</span>'s State Waters and, thus, little accommodation space for sediment accumulation. Sediment is observed offshore in the central part of the map area, in the shelter of the headlands north of the east strand of the San Gregorio Fault (also called the Coastways Fault) around Miramontes Point (about 5 km north of the map area) and also on the outer half of the <span class="hlt">California</span>'s State Waters shelf in the south where depths exceed 40 m. Sediment in the outer shelf of <span class="hlt">California</span>'s State Waters is rippled, indicating some mobility. The Offshore of San Gregorio map area lies within the cold-temperate biogeographic zone that is called either the "Oregonian province" or the "northern <span class="hlt">California</span> ecoregion." This biogeographic province is maintained by the long-term stability of the southward-flowing <span class="hlt">California</span> <span class="hlt">Current</span>, an eastern limb of the North Pacific subtropical gyre that flows from Oregon to Baja <span class="hlt">California</span>. At its midpoint off central <span class="hlt">California</span>, the <span class="hlt">California</span> <span class="hlt">Current</span> transports subarctic surface (0–500 m deep) waters southward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the <span class="hlt">California</span> <span class="hlt">Current</span>, generate coastal upwelling. The south end of the Oregonian province is at Point Conception (about 350 km south of the map area), although its associated phylogeographic group of marine fauna may extend beyond to the area offshore of Los Angeles in southern <span class="hlt">California</span>. The ocean off of central <span class="hlt">California</span> has experienced a warming over the last 50 years that is driving an <span class="hlt">ecosystem</span> shift away from the productive subarctic regime towards a depopulated subtropical environment. Seafloor habitats in the Offshore of San Gregorio map area, which lies within the Shelf (continental shelf) megahabitat, range from significant rocky outcrops that support kelp-forest communities nearshore to rocky-reef communities in deep water. Biological productivity resulting from coastal upwelling supports diverse populations of sea birds such as Sooty Shearwater, Western Gull, Common Murre, Cassin's Auklet, and many other less populous bird species. In addition, an observable recovery of Humpback and Blue Whales has occurred in the area; both species are dependent on coastal upwelling to provide nutrients. The large extent of exposed inner shelf bedrock supports large forests of "bull kelp," which is well adapted for high wave-energy environments. Common fish species found in the kelp beds and rocky reefs include lingcod and various species of rockfish and greenling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ecosystems&pg=3&id=EJ853256','ERIC'); return false;" href="http://eric.ed.gov/?q=ecosystems&pg=3&id=EJ853256"><span id="translatedtitle"><span class="hlt">Ecosystem</span> Jenga!</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Umphlett, Natalie; Brosius, Tierney; Laungani, Ramesh; Rousseau, Joe; Leslie-Pelecky, Diandra L.</p> <p>2009-01-01</p> <p>To give students a tangible model of an <span class="hlt">ecosystem</span> and have them experience what could happen if a component of that <span class="hlt">ecosystem</span> were removed; the authors developed a hands-on, inquiry-based activity that visually demonstrates the concept of a delicately balanced <span class="hlt">ecosystem</span> through a modification of the popular game Jenga. This activity can be…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ecosystems&pg=6&id=EJ721634','ERIC'); return false;" href="http://eric.ed.gov/?q=ecosystems&pg=6&id=EJ721634"><span id="translatedtitle"><span class="hlt">Ecosystem</span> Journalism</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Robertson, Amy; Mahlin, Kathryn</p> <p>2005-01-01</p> <p>If the organisms in a prairie <span class="hlt">ecosystem</span> created a newspaper, what would it look like? What important news topics of the <span class="hlt">ecosystem</span> would the organisms want to discuss? Imaginative and enthusiastic third-grade students were busy pondering these questions as they tried their hands at "<span class="hlt">ecosystem</span> journalism." The class had recently completed a study of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70047601','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70047601"><span id="translatedtitle">Natural <span class="hlt">ecosystems</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fleishman, Erica; Belnap, Jayne; Cobb, Neil; Enquist, Carolyn A.F.; Ford, Karl; MacDonald, Glen; Pellant, Mike; Schoennagel, Tania; Schmit, Lara M.; Schwartz, Mark; van Drunick, Suzanne; Westerling, Anthony LeRoy; Keyser, Alisa; Lucas, Ryan</p> <p>2013-01-01</p> <p>Natural <span class="hlt">Ecosystems</span> analyzes the association of observed changes in climate with changes in the geographic distributions and phenology (the timing of blossoms or migrations of birds) for Southwestern <span class="hlt">ecosystems</span> and their species, portraying <span class="hlt">ecosystem</span> disturbances—such as wildfires and outbreaks of forest pathogens—and carbon storage and release, in relation to climate change.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ecosystems&pg=2&id=EJ853256','ERIC'); return false;" href="http://eric.ed.gov/?q=ecosystems&pg=2&id=EJ853256"><span id="translatedtitle"><span class="hlt">Ecosystem</span> Jenga!</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Umphlett, Natalie; Brosius, Tierney; Laungani, Ramesh; Rousseau, Joe; Leslie-Pelecky, Diandra L.</p> <p>2009-01-01</p> <p>To give students a tangible model of an <span class="hlt">ecosystem</span> and have them experience what could happen if a component of that <span class="hlt">ecosystem</span> were removed; the authors developed a hands-on, inquiry-based activity that visually demonstrates the concept of a delicately balanced <span class="hlt">ecosystem</span> through a modification of the popular game Jenga. This activity can be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=science+AND+journalism&pg=3&id=EJ721634','ERIC'); return false;" href="http://eric.ed.gov/?q=science+AND+journalism&pg=3&id=EJ721634"><span id="translatedtitle"><span class="hlt">Ecosystem</span> Journalism</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Robertson, Amy; Mahlin, Kathryn</p> <p>2005-01-01</p> <p>If the organisms in a prairie <span class="hlt">ecosystem</span> created a newspaper, what would it look like? What important news topics of the <span class="hlt">ecosystem</span> would the organisms want to discuss? Imaginative and enthusiastic third-grade students were busy pondering these questions as they tried their hands at "<span class="hlt">ecosystem</span> journalism." The class had recently completed a study of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70027808','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70027808"><span id="translatedtitle">Comparison of shelf <span class="hlt">currents</span> off central <span class="hlt">California</span> prior to and during the 1997-1998 El Nino</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ryan, H.F.; Noble, M.A.</p> <p>2005-01-01</p> <p>Moored <span class="hlt">current</span>, temperature, salinity, and pressure data were collected at three sites that transect the narrow continental shelf offshore of Davenport, CA, starting in August 1996 and continuing to the spring of 1998. This data set allowed a comparison of oceanographic conditions prior to (8/96-3/97) and during (8/97-3/98) the last major El Nin??o. During this El Nin??o, mean temperatures over the 8-month time period were about 3??C warmer than during the prior year at all of the sites. Correlations between near-surface and near-bottom temperatures, and between near-surface temperature and wind stress decreased during the El Nin??o compared to conditions the year before. The mean alongshore <span class="hlt">currents</span> were more strongly poleward during El Nin??o at sites over the mid-shelf and near the shelf break. There was a general tendency for the energy in alongshore <span class="hlt">currents</span> to move toward lower frequencies during the El Nin??o, particularly at the sites farther offshore. The processes that forced the shelf flows changed in relative importance throughout the study. The local alongshore wind stress was less important in driving shelf <span class="hlt">currents</span> during the El Nin??o when much of the wind-induced upwelling was confined to less than 5 km of the coast. The observed strong poleward shelf <span class="hlt">currents</span> on the mid- to outer-shelf were not clearly tied to local forcing, but were remotely driven, most likely by slope <span class="hlt">currents</span>. The response of the Davenport shelf to an El Nin??o event may differ from other areas since the shelf is narrow, the wind forcing is weaker than areas to the north and south, and the shelf may be at times isolated by fronts that form at strong upwelling centers. In the winter, strong storm-related winds are important in driving <span class="hlt">currents</span> at periods not only in the synoptic wind band, but also for periods on the order of 20 d and longer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/985029','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/985029"><span id="translatedtitle">Chemical Speciation of Sulfur in Marine Cloud Droplets and Particles: Analysis of Individual Particles from the Marine Boundary Layer Over the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hopkins, Rebecca J.; Desyaterik, Yury; Tivanski, Alexei V.; Zaveri, Rahul A.; Berkowitz, Carl M.; Tyliszczak, T.; Gilles, Marry K.; Laskin, Alexander</p> <p>2008-02-27</p> <p>Detailed chemical speciation of the dry residue particles from individual cloud droplets and interstitial aerosol collected during the Marine Stratus Experiment (MASE) was performed using a complementary combination of microanalysis techniques. Techniques include computer controlled scanning electron microscopy with energy dispersed analysis of X-rays (CCSEM/EDX), time-of-flight secondary ionization mass spectrometry (TOFSIMS), and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Samples were collected at the ground site located in Point Reyes National Seashore, approximately 1 km from the coast. This manuscript focuses on the analysis of individual particles sampled from an air mass that originated over the open ocean and then passed through the area of the <span class="hlt">California</span> <span class="hlt">current</span> located along the northern <span class="hlt">California</span> coast. Based on composition, morphology, and chemical bonding information, two externally mixed, distinct classes of sulfur containing particles were identified: chemically modified (aged) sea salt particles and secondary formed sulfate particles. The results indicate substantial heterogeneous replacement of chloride by methanesulfonate (CH3SO3 -) and non-sea salt sulfate (nss-SO4 2-) in sea-salt particles with the characteristic ratios of CH3SO3 ?/nss-SO4 2?> 0.6. Although this value seems too high for a mid-latitude site, our model calculations suggest that high CH3SO3 -/nss-SO4 2- ratios are expected during the early stages of dimethyl sulfide (DMS) oxidation when CH3SO3H forms more rapidly than H2SO4.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70025434','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70025434"><span id="translatedtitle">Long-term, high-frequency <span class="hlt">current</span> and temperature measurements along central <span class="hlt">California</span>: Insights into upwelling/relaxation and internal waves on the inner shelf</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Storlazzi, C.D.; McManus, M.A.; Figurski, J.D.</p> <p>2003-01-01</p> <p>Thermistor chains and acoustic Doppler <span class="hlt">current</span> profilers were deployed at the northern and southern ends of Monterey Bay to examine the thermal and hydrodynamic structure of the inner (h ??? 20 m) shelf of central <span class="hlt">California</span>. These instruments sampled temperature and <span class="hlt">current</span> velocity at 2-min intervals over a 13-month period from June 2000 to July 2001. Time series of these data, in conjunction with SST imagery and CODAR sea surface <span class="hlt">current</span> maps, helped to establish the basic hydrography for Monterey Bay. Analysis of time series data revealed that depth integrated flow at both sites was shore parallel (northwest-southeast) with net flows out of the Bay (northwest). The <span class="hlt">current</span> and temperature records were dominated by semi-diurnal and diurnal tidal signals that lagged the surface tides by 3 h on average. Over the course of an internal tidal cycle these flows were asymmetric, with the flow during the flooding internal tide to the southeast typically lasting only one-third as long as the flow to the northwest during the ebbing internal tide. The transitions from ebb to flood were rapid and bore-like in nature; they were also marked by rapid increases in temperature and high shear. During the spring and summer, when thermal stratification was high, we observed almost 2000 high-frequency (Tp ??? 4-20 min) internal waves in packets of 8-10 following the heads of these bore-like features. Previous studies along the West Coast of the US have concluded that warm water bores and high-frequency internal waves may play a significant role in the onshore transport of larvae.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70164424','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70164424"><span id="translatedtitle">On tide-induced Lagrangian residual <span class="hlt">current</span> and residual transport: 2. Residual transport with application in south San Francisco Bay, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Feng, Shizuo; Cheng, Ralph T.; Pangen, Xi</p> <p>1986-01-01</p> <p>The transports of solutes and other tracers are fundamental to estuarine processes. The apparent transport mechanisms are convection by tidal <span class="hlt">current</span> and <span class="hlt">current</span>-induced shear effect dispersion for processes which take place in a time period of the order of a tidal cycle. However, as emphasis is shifted toward the effects of intertidal processes, the net transport is mainly determined by tide-induced residual circulation and by residual circulation due to other processes. The commonly used intertidal conservation equation takes the form of a convection-dispersion equation in which the convective velocity is the Eulerian residual <span class="hlt">current</span>, and the dispersion terms are often referred to as the phase effect dispersion or, sometimes, as the “tidal dispersion.” The presence of these dispersion terms is merely the result of a Fickian type hypothesis. Since the actual processes are not Fickian, thus a Fickian hypothesis obscures the physical significance of this equation. Recent research results on residual circulation have suggested that long-term transport phenomena are closely related to the Lagrangian residual <span class="hlt">current</span> or the Lagrangian residual transport. In this paper a new formulation of an intertidal conservation equation is presented and examined in detail. In a weakly nonlinear tidal estuary the resultant intertidal transport equation also takes the form of a convection-dispersion equation without the ad hoc introduction of phase effect dispersion in a form of dispersion tensor. The convective velocity in the resultant equation is the first-order Lagrangian residual <span class="hlt">current</span> (the sum of the Eulerian residual <span class="hlt">current</span> and the Stokes drift). The remaining dispersion terms are important only in higher-order solutions; they are due to shear effect dispersion and turbulent mixing. There exists a dispersion boundary layer adjacent to shoreline boundaries. An order of magnitude estimate of the properties in the dispersion boundary layer is given. The present treatment of intertidal transport processes is illustrated by an analytical solution for an amphidromic system and by a numerical application in South San Francisco Bay, <span class="hlt">California</span>. The present formulation reveals that the mechanism for long-term transport of solutes is mainly convection due to the Lagrangian residual <span class="hlt">current</span> in the interior of a tidal estuary. This result also points out the weakness in the tidal dispersion formulation, and explains the large variability of the observed values for tidal dispersion coefficients. Further research on properties of the dispersion boundary layer is needed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26763697','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26763697"><span id="translatedtitle">Resilience and stability of a pelagic marine <span class="hlt">ecosystem</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lindegren, Martin; Checkley, David M; Ohman, Mark D; Koslow, J Anthony; Goericke, Ralf</p> <p>2016-01-13</p> <p>The accelerating loss of biodiversity and <span class="hlt">ecosystem</span> services worldwide has accentuated a long-standing debate on the role of diversity in stabilizing ecological communities and has given rise to a field of research on biodiversity and <span class="hlt">ecosystem</span> functioning (BEF). Although broad consensus has been reached regarding the positive BEF relationship, a number of important challenges remain unanswered. These primarily concern the underlying mechanisms by which diversity increases resilience and community stability, particularly the relative importance of statistical averaging and functional complementarity. Our understanding of these mechanisms relies heavily on theoretical and experimental studies, yet the degree to which theory adequately explains the dynamics and stability of natural <span class="hlt">ecosystems</span> is largely unknown, especially in marine <span class="hlt">ecosystems</span>. Using modelling and a unique 60-year dataset covering multiple trophic levels, we show that the pronounced multi-decadal variability of the Southern <span class="hlt">California</span> <span class="hlt">Current</span> System (SCCS) does not represent fundamental changes in <span class="hlt">ecosystem</span> functioning, but a linear response to key environmental drivers channelled through bottom-up and physical control. Furthermore, we show strong temporal asynchrony between key species or functional groups within multiple trophic levels caused by opposite responses to these drivers. We argue that functional complementarity is the primary mechanism reducing community variability and promoting resilience and stability in the SCCS. PMID:26763697</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/964265','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/964265"><span id="translatedtitle">Annual Report to the Bonneville Power Administration, Reporting Period: April 2008 - February 2009 [re: "Survival and Growth in the Columbia River Plume and north <span class="hlt">California</span> <span class="hlt">Current</span>"].</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Northwest Fisheries Science Center, NOAA Fisheries; Cooperative Institute for Marine Resources Studies, Oregon State University; OGI School of Science & Engineering, Oregon Health Sciences University.</p> <p>2009-07-17</p> <p>We have made substantial progress toward our objectives outlined in our BPA supported proposal entitled 'Columbia River Basin Juvenile Salmonids: Survival and Growth in the Columbia River Plume and northern <span class="hlt">California</span> <span class="hlt">Current</span>' which we report on herein. During 2008, we were able to successfully conduct 3 mesoscale cruises. We also were able to conduct 7 biweekly predator cruises, along with substantial shore-based visual observations of seabirds. Detailed results of the mesoscale cruises are available in the Cruise Reports and summarized in the next section. We have taken a proactive approach to getting the results of our research to fisheries managers and the general public. We have begun to make annual predictions based on ocean conditions of the relative survival of juvenile coho and Chinook salmon well before they return as adults. This is based on both biological and physical indicators that we measure during our surveys or collect from outside data sources. Examples of our predictions for 2009 and 2010 are available on the following web site: http://www.nwfsc.noaa.gov/research/divisions/fed/oeip/a-ecinhome.cfm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/gallery/california_fires_2008','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/gallery/california_fires_2008"><span id="translatedtitle"><span class="hlt">California</span> Fires</span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2014-05-15</p> <p>article title: Smoke Blankets Northern <span class="hlt">California</span> View Larger Image ... strikes sparked more than a thousand fires in northern <span class="hlt">California</span>. This image was captured by the Multi-angle Imaging ... June 27, 2008 - Smoke from fires in northern <span class="hlt">California</span>. project: MISR category: gallery ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=163145&keyword=books&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=55626065&CFTOKEN=29957652','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=163145&keyword=books&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=55626065&CFTOKEN=29957652"><span id="translatedtitle">AQUATIC <span class="hlt">ECOSYSTEMS</span>,</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Aquatic <span class="hlt">ecosystems</span> are a vital part of the urban water cycle (and of urban areas more broadly), and, if healthy, provide a range of goods and services valued by humans (Meyer 1997). For example, aquatic <span class="hlt">ecosystems</span> (e.g., rivers, lakes, wetlands) provide potable water, food resou...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5097130','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5097130"><span id="translatedtitle">Agricultural <span class="hlt">ecosystems</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kindscher, K.</p> <p>1984-01-01</p> <p>The agricultural <span class="hlt">ecosystem</span> concept promotes a distinctive set of ecological principles that give diversity and stability to the food production process. This system allows people to work more closely with nature and to feel a spiritual connection with the earth. Agricultural <span class="hlt">ecosystems</span> can be designed to provide numerous advantages. They can be energy conserving, more permanent, make better use of space, reduce and eliminate the need for pesticides, tillage, and chemical fertilizers, and provide food for the local community. The agricultural <span class="hlt">ecosystem</span> model presented is most suitable for a small-scale farmer or market gardener, but the principles can also be applied on a larger or smaller acreage. The agricultural <span class="hlt">ecosystem</span> concept is a model-building process that will go through successional stages to a more mature food-producing plant community. The agricultural <span class="hlt">ecosystem</span> concept expresses permanence and ecology, and is a step toward sustainable agriculture. 55 references, 4 figures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B33A0156G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B33A0156G"><span id="translatedtitle">Hydrological Controls on <span class="hlt">Ecosystem</span> CO2 and CH4 Exchange in a MIXED Tundra and a FEN within an Arctic Landscape UNDER <span class="hlt">Current</span> and Future Climates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grant, R. F.; Humphreys, E.; Lafleur, P.</p> <p>2014-12-01</p> <p>Variation in CO2 and CH4 exchange in years with contrasting weather is strongly affected by hydrology in landscapes underlain by permafrost. Hypotheses for this variation were incorporated into the <span class="hlt">ecosystem</span> model ecosys which simulated CO2 and CH4 fluxes along a topographic gradient within an arctic landscape at Daring Lake, NWT, Canada. Fluxes modelled at mixed tundra and fen sites within the gradient were compared with CO2 fluxes measured at eddy covariance towers from 2006 to 2009, and with CH4 fluxes measured with surface chambers in 2008. Slopes and correlation coefficients from regressions of modelled vs. measured CO2 fluxes were 1.0 0.1 and 0.7 - 0.8 for both sites in all years. At the mixed tundra site, rises in net CO2 uptake in warmer years with earlier snowmelt were constrained by midafternoon declines in CO2 influxes when vapor pressure deficits (D) exceeded 1.5 kPa, and by rises in CO2 effluxes with greater active layer depth (ALD). Consequently annual net CO2 uptake at this site rose little with warming. At the fen site, CO2 influxes declined less with D and CO2 effluxes rose less with warming, so that rises in net CO2 uptake in warmer years were greater than those at the mixed tundra site. The greater declines in CO2 influxes with warming at the mixed tundra site were modelled from greater soil-plant-atmosphere water potential gradients that developed in drier soil, and the smaller rises in CO2 effluxes with warming at the fen site were modelled from O2 constraints to heterotrophic and below-ground autotrophic respiration that limited their responses to greater ALD. Modelled and measured CH4 exchange during July and August indicated very small influxes at the mixed tundra site, and larger emissions at the fen site. Emissions of CH4 modelled during soil freezing in October - November contributed about one-third of the annual total, and so should be included in estimates of annual emissions. These contrasting responses to warming under <span class="hlt">current</span> climate modelled and measured at the mixed tundra and fen sites were apparent in their contrasting responses modelled under long-term climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGD....10.5803S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGD....10.5803S"><span id="translatedtitle">Measurements of nitrite production and nitrite-producing organisms in and around the primary nitrite maximum in the central <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Santoro, A. E.; Sakamoto, C. M.; Smith, J. M.; Plant, J. N.; Gehman, A. L.; Worden, A. Z.; Johnson, K. S.; Francis, C. A.; Casciotti, K. L.</p> <p>2013-03-01</p> <p>Nitrite (NO2-) is a substrate for both oxidative and reductive microbial metabolism. NO2- accumulates at the base of the euphotic zone in oxygenated, stratified open ocean water columns, forming a feature known as the primary nitrite maximum (PNM). Potential pathways of NO2- production include the oxidation of ammonia (NH3) by ammonia-oxidizing bacteria or archaea and assimilatory nitrate (NO3-) reduction by phytoplankton or heterotrophic bacteria. Measurements of NH3 oxidation and NO3- reduction to NO2- were conducted at two stations in the central <span class="hlt">California</span> <span class="hlt">Current</span> in the eastern North Pacific to determine the relative contributions of these processes to NO2- production in the PNM. Sensitive (< 10 nmol L-1), high-resolution measurements of [NH4+] and [NO2-] indicated a persistent NH4+ maximum overlying the PNM at every station, with concentrations as high as 1.5 ?mol L-1. Within and just below the PNM, NH3 oxidation was the dominant NO2- producing process with rates of NH3 oxidation of up to 50 nmol L-1 d-1, coinciding with high abundances of ammonia-oxidizing archaea. Though little NO2- production from NO3- was detected, potentially nitrate-reducing phytoplankton (photosynthetic picoeukaryotes, Synechococcus, and Prochlorococcus) were present at the depth of the PNM. Rates of NO2- production from NO3- were highest within the upper mixed layer (4.6 nmol L-1 d-1) but were either below detection limits or 10 times lower than NH3 oxidation rates around the PNM. One-dimensional modeling of water column NO2- profiles supported direct rate measurements of a net biological sink for NO2- just below the PNM. Residence time estimates of NO2- within the PNM were similar at the mesotrophic and oligotrophic stations and ranged from 150-205 d. Our results suggest the PNM is a dynamic, rather than relict, feature with a source term dominated by ammonia oxidation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15940400','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15940400"><span id="translatedtitle">Phreatophytic vegetation and groundwater fluctuations: a review of <span class="hlt">current</span> research and application of <span class="hlt">ecosystem</span> response modeling with an emphasis on great basin vegetation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Naumburg, Elke; Mata-Gonzalez, Ricardo; Hunter, Rachael G; McLendon, Terry; Martin, David W</p> <p>2005-06-01</p> <p>Although changes in depth to groundwater occur naturally, anthropogenic alterations may exacerbate these fluctuations and, thus, affect vegetation reliant on groundwater. These effects include changes in physiology, structure, and community dynamics, particularly in arid regions where groundwater can be an important water source for many plants. To properly manage <span class="hlt">ecosystems</span> subject to changes in depth to groundwater, plant responses to both rising and falling groundwater tables must be understood. However, most research has focused exclusively on riparian <span class="hlt">ecosystems</span>, ignoring regions where groundwater is available to a wider range of species. Here, we review responses of riparian and other species to changes in groundwater levels in arid environments. Although decreasing water tables often result in plant water stress and reduced live biomass, the converse is not necessarily true for rising water tables. Initially, rising water tables kill flooded roots because most species cannot tolerate the associated low oxygen levels. Thus, flooded plants can also experience water stress. Ultimately, individual species responses to either scenario depend on drought and flooding tolerance and the change in root system size and water uptake capacity. However, additional environmental and biological factors can play important roles in the severity of vegetation response to altered groundwater tables. Using the reviewed information, we created two conceptual models to highlight vegetation dynamics in areas with groundwater fluctuations. These models use flow charts to identify key vegetation and <span class="hlt">ecosystem</span> properties and their responses to changes in groundwater tables to predict community responses. We then incorporated key concepts from these models into EDYS, a comprehensive <span class="hlt">ecosystem</span> model, to highlight the potential complexity of predicting community change under different fluctuating groundwater scenarios. Such models provide a valuable tool for managing vegetation and groundwater use in areas where groundwater is important to both plants and humans, particularly in the context of climate change. PMID:15940400</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=power+AND+electronic&pg=7&id=ED563166','ERIC'); return false;" href="http://eric.ed.gov/?q=power+AND+electronic&pg=7&id=ED563166"><span id="translatedtitle">Female Superintendent Longevity in <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rohlfing, Tracy</p> <p>2011-01-01</p> <p>The purpose of this study was to investigate, through narrative inquiry (Clandinin & Connelly, 2000), the leadership evolution of five female superintendents in <span class="hlt">California</span> with longevity of 5 or more years in their <span class="hlt">current</span> school district positions. The research question addressed was, "How do <span class="hlt">California</span> female superintendents evolve to…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=leadership+AND+theories&pg=6&id=ED563166','ERIC'); return false;" href="http://eric.ed.gov/?q=leadership+AND+theories&pg=6&id=ED563166"><span id="translatedtitle">Female Superintendent Longevity in <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rohlfing, Tracy</p> <p>2011-01-01</p> <p>The purpose of this study was to investigate, through narrative inquiry (Clandinin & Connelly, 2000), the leadership evolution of five female superintendents in <span class="hlt">California</span> with longevity of 5 or more years in their <span class="hlt">current</span> school district positions. The research question addressed was, "How do <span class="hlt">California</span> female superintendents evolve to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED072757.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED072757.pdf"><span id="translatedtitle">Financing Postsecondary Education in <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>California State Legislature, Sacramento. Joint Committee on the Master Plan for Higher Education.</p> <p></p> <p>This document presents an overview of the financial aspects of postsecondary educational institutions in <span class="hlt">California</span> and suggests some recommendations for the alleviation of financial problems. The study consisted of extensive research of the <span class="hlt">current</span> literature on financing, gathering key data on the <span class="hlt">California</span> system, reviewing the pertinent…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7025823','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7025823"><span id="translatedtitle">Freshwater <span class="hlt">ecosystems</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Straskraba, M.; Gnauck, A.H.</p> <p>1985-01-01</p> <p><span class="hlt">Ecosystem</span> analysis and ecological modelling is a rapidly developing interdisciplinary branch of science used in theoretical developments in ecology and having practical applications in environmental protection. In this book, the authors introduce new holistic, particularly cybernetic, concepts into <span class="hlt">ecosystem</span> theory and modelling, and provide a concise treatment of mathematical modelling of freshwater <span class="hlt">ecosystems</span> which covers methods, subsystem models, applications and theoretical developments. Part 1 begins with a brief introduction to the principles of systems theory and their applications to <span class="hlt">ecosystems</span>, and provides a summary of various methods of systems analysis. In Part 11 emphasis is laid on the pelagic processes in standing water, characterised by relatively uninvolved structures from which models can be readily developed. Part 111 describes applications of the technique of modelling to solutions of theoretical and practical problems, with different modelling methods and objectives being used in the various chapters. More recent developments in the methods and theory of <span class="hlt">ecosystem</span> modelling are covered in Part 1V which also includes a discussion of future trends.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19659684','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19659684"><span id="translatedtitle">Obscuring <span class="hlt">ecosystem</span> function with application of the <span class="hlt">ecosystem</span> services concept.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peterson, Markus J; Hall, Damon M; Feldpausch-Parker, Andrea M; Peterson, Tarla Rai</p> <p>2010-02-01</p> <p>Conservationists commonly have framed ecological concerns in economic terms to garner political support for conservation and to increase public interest in preserving global biodiversity. Beginning in the early 1980s, conservation biologists adapted neoliberal economics to reframe <span class="hlt">ecosystem</span> functions and related biodiversity as <span class="hlt">ecosystem</span> services to humanity. Despite the economic success of programs such as the Catskill/Delaware watershed management plan in the United States and the creation of global carbon exchanges, today's marketplace often fails to adequately protect biodiversity. We used a Marxist critique to explain one reason for this failure and to suggest a possible, if partial, response. Reframing <span class="hlt">ecosystem</span> functions as economic services does not address the political problem of commodification. Just as it obscures the labor of human workers, commodification obscures the importance of the biota (<span class="hlt">ecosystem</span> workers) and related abiotic factors that contribute to <span class="hlt">ecosystem</span> functions. This erasure of work done by <span class="hlt">ecosystems</span> impedes public understanding of biodiversity. Odum and Odum's radical suggestion to use the language of <span class="hlt">ecosystems</span> (i.e., emergy or energy memory) to describe economies, rather than using the language of economics (i.e., services) to describe <span class="hlt">ecosystems</span>, reverses this erasure of the <span class="hlt">ecosystem</span> worker. Considering the <span class="hlt">current</span> dominance of economic forces, however, implementing such solutions would require social changes similar in magnitude to those that occurred during the 1960s. Niklas Luhmann argues that such substantive, yet rapid, social change requires synergy among multiple societal function systems (i.e., economy, education, law, politics, religion, science), rather than reliance on a single social sphere, such as the economy. Explicitly presenting <span class="hlt">ecosystem</span> services as discreet and incomplete aspects of <span class="hlt">ecosystem</span> functions not only allows potential economic and environmental benefits associated with <span class="hlt">ecosystem</span> services, but also enables the social and political changes required to ensure valuation of <span class="hlt">ecosystem</span> functions and related biodiversity in ways beyond their measurement on an economic scale. PMID:19659684</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://gallery.usgs.gov/photos/02_24_2010_y17Gxk3WVq_02_24_2010_1','SCIGOVIMAGE-USGS'); return false;" href="http://gallery.usgs.gov/photos/02_24_2010_y17Gxk3WVq_02_24_2010_1"><span id="translatedtitle"><span class="hlt">California</span> Condor</span></a></p> <p><a target="_blank" href="http://gallery.usgs.gov/">USGS Multimedia Gallery</a></p> <p></p> <p></p> <p><span class="hlt">California</span> condors are one of the most endangered birds in North America. In the early 1990s, captive-bred condors were reintroduced into the wild in <span class="hlt">California</span>. As of January 2010, about 190 condors now live in the wild and more reintroductions are being considered. To facilitate this, USGS researc...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1629036','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1629036"><span id="translatedtitle">Conservation Planning for <span class="hlt">Ecosystem</span> Services</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chan, Kai M. A; Shaw, M. Rebecca; Cameron, David R; Underwood, Emma C; Daily, Gretchen C</p> <p>2006-01-01</p> <p>Despite increasing attention to the human dimension of conservation projects, a rigorous, systematic methodology for planning for <span class="hlt">ecosystem</span> services has not been developed. This is in part because flows of <span class="hlt">ecosystem</span> services remain poorly characterized at local-to-regional scales, and their protection has not generally been made a priority. We used a spatially explicit conservation planning framework to explore the trade-offs and opportunities for aligning conservation goals for biodiversity with six <span class="hlt">ecosystem</span> services (carbon storage, flood control, forage production, outdoor recreation, crop pollination, and water provision) in the Central Coast ecoregion of <span class="hlt">California</span>, United States. We found weak positive and some weak negative associations between the priority areas for biodiversity conservation and the flows of the six <span class="hlt">ecosystem</span> services across the ecoregion. Excluding the two agriculture-focused servicescrop pollination and forage productioneliminates all negative correlations. We compared the degree to which four contrasting conservation network designs protect biodiversity and the flow of the six services. We found that biodiversity conservation protects substantial collateral flows of services. Targeting <span class="hlt">ecosystem</span> services directly can meet the multiple <span class="hlt">ecosystem</span> services and biodiversity goals more efficiently but cannot substitute for targeted biodiversity protection (biodiversity losses of 44% relative to targeting biodiversity alone). Strategically targeting only biodiversity plus the four positively associated services offers much promise (relative biodiversity losses of 7%). Here we present an initial analytical framework for integrating biodiversity and <span class="hlt">ecosystem</span> services in conservation planning and illustrate its application. We found that although there are important potential trade-offs between conservation for biodiversity and for <span class="hlt">ecosystem</span> services, a systematic planning framework offers scope for identifying valuable synergies. PMID:17076586</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Income+AND+tax&pg=4&id=ED561986','ERIC'); return false;" href="http://eric.ed.gov/?q=Income+AND+tax&pg=4&id=ED561986"><span id="translatedtitle"><span class="hlt">California</span>'s Future: Higher Education</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Johnson, Hans</p> <p>2015-01-01</p> <p><span class="hlt">California</span>'s higher education system is not keeping up with the changing economy. Projections suggest that the state's economy will continue to need more highly educated workers. In 2025, if <span class="hlt">current</span> trends persist, 41 percent of jobs will require at least a bachelor's degree and 36 percent will require some college education short of a bachelor's</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/822264','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/822264"><span id="translatedtitle">Review of <span class="hlt">current</span> Southern <span class="hlt">California</span> edison load management programs and proposal for a new market-driven, mass-market, demand-response program</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weller, G.H.</p> <p>2002-01-01</p> <p>Utility load management programs, including direct load control and interruptible load programs, constitute a large installed base of controllable loads that are employed by utilities as system reliability resources. In response to energy supply shortfalls expected during the summer of 2001, the <span class="hlt">California</span> Public Utilities Commission in spring 2001 authorized new utility load management programs as well as revisions to existing programs. This report provides an independent review of the designs of these new programs for a large utility (Southern <span class="hlt">California</span> Edison) and suggests possible improvements to enhance the price responsiveness of the customer actions influenced by these programs. The report also proposes a new program to elicit a mass-market demand response to utility price signals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3440624','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3440624"><span id="translatedtitle">Stable Isotope Analysis Challenges Wasp-Waist Food Web Assumptions in an Upwelling Pelagic <span class="hlt">Ecosystem</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Madigan, Daniel J.; Carlisle, Aaron B.; Dewar, Heidi; Snodgrass, Owyn E.; Litvin, Steven Y.; Micheli, Fiorenza; Block, Barbara A.</p> <p>2012-01-01</p> <p>Eastern boundary <span class="hlt">currents</span> are often described as ‘wasp-waist’ <span class="hlt">ecosystems</span> in which one or few mid-level forage species support a high diversity of larger predators that are highly susceptible to fluctuations in prey biomass. The assumption of wasp-waist control has not been empirically tested in all such <span class="hlt">ecosystems</span>. This study used stable isotope analysis to test the hypothesis of wasp-waist control in the southern <span class="hlt">California</span> <span class="hlt">Current</span> large marine <span class="hlt">ecosystem</span> (CCLME). We analyzed prey and predator tissue for δ13C and δ15N and used Bayesian mixing models to provide estimates of CCLME trophic dynamics from 2007–2010. Our results show high omnivory, planktivory by some predators, and a higher degree of trophic connectivity than that suggested by the wasp-waist model. Based on this study period, wasp-waist models oversimplify trophic dynamics within the CCLME and potentially other upwelling, pelagic <span class="hlt">ecosystems</span>. Higher trophic connectivity in the CCLME likely increases <span class="hlt">ecosystem</span> stability and resilience to perturbations. PMID:22977729</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PrOce.138..348R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PrOce.138..348R"><span id="translatedtitle">Demonstration of a fully-coupled end-to-end model for small pelagic fish using sardine and anchovy in the <span class="hlt">California</span> <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rose, Kenneth A.; Fiechter, Jerome; Curchitser, Enrique N.; Hedstrom, Kate; Bernal, Miguel; Creekmore, Sean; Haynie, Alan; Ito, Shin-ichi; Lluch-Cota, Salvador; Megrey, Bernard A.; Edwards, Chris A.; Checkley, Dave; Koslow, Tony; McClatchie, Sam; Werner, Francisco; MacCall, Alec; Agostini, Vera</p> <p>2015-11-01</p> <p>We describe and document an end-to-end model of anchovy and sardine population dynamics in the <span class="hlt">California</span> <span class="hlt">Current</span> as a proof of principle that such coupled models can be developed and implemented. The end-to-end model is 3-dimensional, time-varying, and multispecies, and consists of four coupled submodels: hydrodynamics, Eulerian nutrient-phytoplankton-zooplankton (NPZ), an individual-based full life cycle anchovy and sardine submodel, and an agent-based fishing fleet submodel. A predator roughly mimicking albacore was included as individuals that consumed anchovy and sardine. All submodels were coded within the ROMS open-source community model, and used the same resolution spatial grid and were all solved simultaneously to allow for possible feedbacks among the submodels. We used a super-individual approach and solved the coupled models on a distributed memory parallel computer, both of which created challenging but resolvable bookkeeping challenges. The anchovy and sardine growth, mortality, reproduction, and movement, and the fishing fleet submodel, were each calibrated using simplified grids before being inserted into the full end-to-end model. An historical simulation of 1959-2008 was performed, and the latter 45 years analyzed. Sea surface height (SSH) and sea surface temperature (SST) for the historical simulation showed strong horizontal gradients and multi-year scale temporal oscillations related to various climate indices (PDO, NPGO), and both showed responses to ENSO variability. Simulated total phytoplankton was lower during strong El Nino events and higher for the strong 1999 La Nina event. The three zooplankton groups generally corresponded to the spatial and temporal variation in simulated total phytoplankton. Simulated biomasses of anchovy and sardine were within the historical range of observed biomasses but predicted biomasses showed much less inter-annual variation. Anomalies of annual biomasses of anchovy and sardine showed a switch in the mid-1990s from anchovy to sardine dominance. Simulated averaged weights- and lengths-at-age did not vary much across decades, and movement patterns showed anchovy located close to the coast while sardine were more dispersed and farther offshore. Albacore predation on anchovy and sardine was concentrated near the coast in two pockets near the Monterey Bay area and equatorward of Cape Mendocino. Predation mortality from fishing boats was concentrated where sardine age-1 and older individuals were located close to one of the five ports. We demonstrated that it is feasible to perform multi-decadal simulations of a fully-coupled end-to-end model, and that this can be done for a model that follows individual fish and boats on the same 3-dimensional grid as the hydrodynamics. Our focus here was on proof of principle and our results showed that we solved the major technical, bookkeeping, and computational issues. We discuss the next steps to increase computational speed and to include important biological differences between anchovy and sardine. In a companion paper (Fiechter et al., 2015), we further analyze the historical simulation in the context of the various hypotheses that have been proposed to explain the sardine and anchovy cycles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.6437F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.6437F"><span id="translatedtitle">Facilitating Next Generation Science Collaboration: Respecting and Mediating Vocabularies with Information Model Driven Semantics in <span class="hlt">Ecosystems</span> Assessments.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fox, P.; Maffei, A.</p> <p>2012-04-01</p> <p>In Earth and space science, there is steady evolution away from isolated and single purpose data 'systems' toward systems of systems, data <span class="hlt">ecosystems</span>, or data frameworks that provide access to highly heterogeneous data repositories. As a result, common informatics approaches are being sought for the development and implementation of newer architectures. One clear need is a repeatable method for modeling, implementing and evolving the information architectures. A newly funded U.S. initiative is developing and deploying integrated <span class="hlt">ecosystem</span> assessment (IEA) capability for marine <span class="hlt">ecosystems</span> using an information science and semantic technologies. The intention is to advance the capacity of an IEA to provide the foundation for synthesis and quantitative analysis of natural and socio-economic <span class="hlt">ecosystem</span> information to support <span class="hlt">ecosystem</span>-based management. The initiative is creating capacity to assess the impacts of changing climate on two large marine <span class="hlt">ecosystems</span>: the northeast U.S. and the <span class="hlt">California</span> <span class="hlt">Current</span>. These assessments will be essential parts of the science-based decision-support tools used to develop adaptive management measures. Enhanced collaboration is required to achieve these goals: interaction and information sharing within and among diverse data providers, analysis tool developers and user groups that constitute the broader coastal and marine <span class="hlt">ecosystem</span> science application community. This presentation outlines new component design approaches and sets of information model and semantic encodings for mediation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1209197','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1209197"><span id="translatedtitle">Predicting long-term carbon sequestration in response to CO<sub>2</sub> enrichment: How and why do <span class="hlt">current</span> <span class="hlt">ecosystem</span> models differ?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Walker, Anthony P.; Zaehle, Sönke; Medlyn, Belinda E.; De Kauwe, Martin G.; Asao, Shinichi; Hickler, Thomas; Parton, William; Ricciuto, Daniel M.; Wang, Ying -Ping; Wårlind, David; Norby, Richard J.</p> <p>2015-04-27</p> <p>Large uncertainty exists in model projections of the land carbon (C) sink response to increasing atmospheric CO<sub>2</sub>. Free-Air CO<sub>2</sub> Enrichment (FACE) experiments lasting a decade or more have investigated <span class="hlt">ecosystem</span> responses to a step change in atmospheric CO<sub>2</sub> concentration. To interpret FACE results in the context of gradual increases in atmospheric CO<sub>2</sub> over decades to centuries, we used a suite of seven models to simulate the Duke and Oak Ridge FACE experiments extended for 300 years of CO<sub>2</sub> enrichment. We also determine key modeling assumptions that drive divergent projections of terrestrial C uptake and evaluate whether these assumptions can be constrained by experimental evidence. All models simulated increased terrestrial C pools resulting from CO<sub>2</sub> enrichment, though there was substantial variability in quasi-equilibrium C sequestration and rates of change. In two of two models that assume that plant nitrogen (N) uptake is solely a function of soil N supply, the net primary production response to elevated CO<sub>2</sub> became progressively N limited. In four of five models that assume that N uptake is a function of both soil N supply and plant N demand, elevated CO<sub>2</sub> led to reduced <span class="hlt">ecosystem</span> N losses and thus progressively relaxed nitrogen limitation. Many allocation assumptions resulted in increased wood allocation relative to leaves and roots which reduced the vegetation turnover rate and increased C sequestration. Additionally, self-thinning assumptions had a substantial impact on C sequestration in two models. As a result, accurate representation of N process dynamics (in particular N uptake), allocation, and forest self-thinning is key to minimizing uncertainty in projections of future C sequestration in response to elevated atmospheric CO<sub>2</sub>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/gallery/california_fires_2009','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/gallery/california_fires_2009"><span id="translatedtitle"><span class="hlt">California</span> Fires</span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2014-05-15</p> <p>article title:  Smoke from Station Fire Blankets Southern <span class="hlt">California</span>     ... 105,000 acres (164 square miles) of the Angeles National Forest by mid-day August 31, destroying at least 21 homes and threatening more ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24421878','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24421878"><span id="translatedtitle">Quantifying water flow within aquatic <span class="hlt">ecosystems</span> using load cell sensors: a profile of <span class="hlt">currents</span> experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Johansen, Jacob L</p> <p>2014-01-01</p> <p><span class="hlt">Current</span> velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these <span class="hlt">currents</span> has proven difficult. This study utilises a simple and inexpensive instrument (<$150) to provide a detailed <span class="hlt">current</span> velocity profile of the coral-reef system around Lizard Island (Great Barrier Reef, Australia) at a spatial and temporal scale relevant to the ecology of individual benthos and fish. The instrument uses load-cell sensors to provide a correlation between sensor output and ambient <span class="hlt">current</span> velocity of 99%. Each instrument is able to continuously record <span class="hlt">current</span> velocities to >500 cms? and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.060.04%, and accuracy of 0.510.65% (mean S.D.). Each instrument is also pressure rated to 120 m and shear stresses ?20 kNm? allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m), mid-slope (6 m) and deep-slope (9 m depth) of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that <span class="hlt">currents</span> over the reef slope and crest varies immensely depending on depth and exposure: <span class="hlt">currents</span> differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that <span class="hlt">currents</span> around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to <span class="hlt">currents</span> of 0 to >82 cms?, while tidal <span class="hlt">currents</span> rarely exceed 5.5 cms?. Rather, <span class="hlt">current</span> velocity increases exponentially as a function of wave height (0 to 1.6 m) and frequency (0.54 to 0.20 Hz), emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats. PMID:24421878</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED474908.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED474908.pdf"><span id="translatedtitle"><span class="hlt">California</span>'s Accountability System and the API. Expert Report. Submitted for: Eliezer Williams vs. State of <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Russell, Michael</p> <p></p> <p>This paper was presented as expert testimony in the Williams vs. State of <span class="hlt">California</span> class action lawsuit. That case, filed on behalf of <span class="hlt">California</span> public schoolchildren, charged the State with denying thousands of students the basic tools for a sound education. This paper addresses whether <span class="hlt">California</span>'s <span class="hlt">current</span> output-based accountability system…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3885433','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3885433"><span id="translatedtitle">Quantifying Water Flow within Aquatic <span class="hlt">Ecosystems</span> Using Load Cell Sensors: A Profile of <span class="hlt">Currents</span> Experienced by Coral Reef Organisms around Lizard Island, Great Barrier Reef, Australia</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Johansen, Jacob L.</p> <p>2014-01-01</p> <p><span class="hlt">Current</span> velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these <span class="hlt">currents</span> has proven difficult. This study utilises a simple and inexpensive instrument (<$150) to provide a detailed <span class="hlt">current</span> velocity profile of the coral-reef system around Lizard Island (Great Barrier Reef, Australia) at a spatial and temporal scale relevant to the ecology of individual benthos and fish. The instrument uses load-cell sensors to provide a correlation between sensor output and ambient <span class="hlt">current</span> velocity of 99%. Each instrument is able to continuously record <span class="hlt">current</span> velocities to >500 cms−1 and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.). Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm−2 allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m), mid-slope (6 m) and deep-slope (9 m depth) of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that <span class="hlt">currents</span> over the reef slope and crest varies immensely depending on depth and exposure: <span class="hlt">Currents</span> differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that <span class="hlt">currents</span> around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to <span class="hlt">currents</span> of 0 to >82 cms−1, while tidal <span class="hlt">currents</span> rarely exceed 5.5 cms−1. Rather, <span class="hlt">current</span> velocity increases exponentially as a function of wave height (0 to 1.6 m) and frequency (0.54 to 0.20 Hz), emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats. PMID:24421878</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMGC33C..04L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMGC33C..04L"><span id="translatedtitle">Climate change adaptation potential for water in <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lund, J. R.</p> <p>2008-12-01</p> <p><span class="hlt">California</span> has an extensive, diverse, and highly interconnected water management system which serves a wide variety of purposes. Climatic change can have many effects on this system and there are many means to manage <span class="hlt">California</span>'s water systems with climatic change. Many studies of climate change in <span class="hlt">California</span> support several conclusions that will be the focus of the talk. But more work is needed. Climatic change's effects on <span class="hlt">California</span>'s water system will coincide with significant population growth, economic change, technology development, and continuing evolution of water management for these and other reasons. <span class="hlt">California</span>'s large and highly-interconnected water infrastructure system provides many options for responding to climatic and other changes, and its decentralized water management system, while noisy, can provide a more responsive and thorough means of responding to climatic change. Large amounts of surface and groundwater storage significantly dampen the water supply effects of a seasonal shift in runoff. While a seasonal shift in runoff is inconvenient and adds costs for water supply, it is probably not the most vulnerable to climate warming. The water supply system is more vulnerable to long- term reductions in streamflow or persistent droughts, drier forms of climate change. The <span class="hlt">current</span> water conveyance system is also highly vulnerable to sea level rise in the Sacramento-San Joaquin Delta. The flood management system is less well studied for climate change, but appears to be far more vulnerable to climate warming, especially wetter forms of climate warming. Revising reservoir flood operations manuals is like to be needed, along with changes to downstream infrastructure and land use. The <span class="hlt">ecosystem</span> is probably the most vulnerable major water use to climatic change. Warmer marine and inland water temperatures combined with seasonal shifts and continued loss of habitat will increase challenges to native species, and in some cases these challenges are likely to be overwhelming.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JMS...132....1L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JMS...132....1L"><span id="translatedtitle">Pelagic amphipod assemblage associated with subarctic water off the West Coast of the Baja <span class="hlt">California</span> peninsula</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lavaniegos, Bertha E.</p> <p>2014-04-01</p> <p>The <span class="hlt">California</span> <span class="hlt">Current</span> system is a large marine <span class="hlt">ecosystem</span> with transition gradients between subarctic and tropical biomes containing diverse habitats. Biogeographic species groups must be carefully analyzed in order to detect tendencies shifting the <span class="hlt">ecosystem</span> toward a more temperate or tropical state. Species composition of hyperiid amphipods was analyzed in July 2002 for evidence of subarctic water intrusion and for signals of the El Niño event developing in the equatorial Pacific. Multivariate analysis showed a dominance of “transition zone” species typical of the <span class="hlt">California</span> <span class="hlt">Current</span>. The main evidence of subarctic water intrusion was the extended distribution of Themisto pacifica, which reached as far south as 27°N, with particularly high abundances at 30-32°N. The intrusion of subarctic water took place despite evidence that an El Niño event was in progress. The zonal advection due to El Niño intersected the equatorward flow of the subarctic intrusion and probably produced a large cyclonic eddy off Baja <span class="hlt">California</span>. This eddy maintained a limited El Niño influence at a few offshore stations near its southern boundary. The main environmental variables influencing the amphipod assemblage structure were water temperature and the abundance of salps. T. pacifica, a species with cool water affinity, was more sensitive to temperature, whereas subtropical species, such as Vibilia armata, were strongly correlated with the availability of salps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740022685&hterms=streams+california&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dstreams%2Bcalifornia','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740022685&hterms=streams+california&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dstreams%2Bcalifornia"><span id="translatedtitle"><span class="hlt">California</span> coastal processes study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pirie, D. M.; Steller, D. D.</p> <p>1974-01-01</p> <p>Preliminary findings are presented and applications derived from ERTS-1 satellite imagery of the nearshore coastal processes of the <span class="hlt">California</span> coast. The objectives were to analyze nearshore <span class="hlt">currents</span>, sediment transport, and estuarine and river discharges along the <span class="hlt">California</span> coast through the use of synoptic and repetitive imagery from ERTS as well as aircraft underflights and surface data. The major conclusions are: (1) Distinct seasonal patterns for sediment transport as a function of the oceanic <span class="hlt">current</span> systems and coastal morphology have been identified. (2) Large scale sediment plumes from intermittent streams and rivers extend offshore to previously unanticipated ranges. (3) Computer generated contouring of radiance levels from computer-compatible tapes result in charts that can be used for determination of surface and nearsurface suspended sediment distribution. (4) Flying spot scanner enhancements result in details of nearshore features. (5) Data is providing significant information for coastal planning and construction projects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=142396&keyword=concentrated+AND+animal+AND+feed+AND+operation&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=55662948&CFTOKEN=73318936','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=142396&keyword=concentrated+AND+animal+AND+feed+AND+operation&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=55662948&CFTOKEN=73318936"><span id="translatedtitle"><span class="hlt">CALIFORNIA</span> DAIRIES</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>These dairy records were collected by the <span class="hlt">California</span> Department of Food and Agriculture (CDFA) as part of a trial for disease surveillance and prevention purposes. Some records contain GPS coordinates, while the remaining records were obtained through address matching methods u...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/gallery/california_fires_2003','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/gallery/california_fires_2003"><span id="translatedtitle"><span class="hlt">California</span> Fires</span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2014-05-15</p> <p>article title: Wildfires Rage in Southern <span class="hlt">California</span> ... Image Large plumes of smoke rising from devastating wildfires burning near Los Angeles and San Diego on Sunday, October 26, 2003, ... at JPL October 26, 2003 - Smoke from wildfires near Los Angeles and San Diego. project: MISR ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=QAS&pg=6&id=EJ960784','ERIC'); return false;" href="http://eric.ed.gov/?q=QAS&pg=6&id=EJ960784"><span id="translatedtitle"><span class="hlt">California</span> Dreaming</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Olson, Cathy Applefeld</p> <p>2011-01-01</p> <p>After getting her master's degree from UCLA, Nancy Wills dreamed of starting a school-based guitar program so she could teach students to make music on the instrument she'd loved since she was a kid growing up outside of Yosemite, <span class="hlt">California</span>. She had a strong belief that guitar was perfect for schools, ideal for individualized playing but also…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=playing+AND+guitar&id=EJ960784','ERIC'); return false;" href="http://eric.ed.gov/?q=playing+AND+guitar&id=EJ960784"><span id="translatedtitle"><span class="hlt">California</span> Dreaming</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Olson, Cathy Applefeld</p> <p>2011-01-01</p> <p>After getting her master's degree from UCLA, Nancy Wills dreamed of starting a school-based guitar program so she could teach students to make music on the instrument she'd loved since she was a kid growing up outside of Yosemite, <span class="hlt">California</span>. She had a strong belief that guitar was perfect for schools, ideal for individualized playing but also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/gallery/california_dust','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/gallery/california_dust"><span id="translatedtitle"><span class="hlt">California</span> Dust</span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2014-05-15</p> <p>... in this image is a blue-gray smoke plume from a small fire located near the southern flank of Palomar Mountain in Southern <span class="hlt">California</span>. ... location:  United States region:  Western United States Order:  37 thumbnail:  ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6486307','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6486307"><span id="translatedtitle">What next for <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lang, P.</p> <p>1982-11-01</p> <p>The effect of Governor Jerry Brown on the solar industry in <span class="hlt">California</span> is reviewed. It is pointed out that <span class="hlt">currently</span> there are 7000 solar businesses; before Gov. Brown's administration there were virtually none. The effect of Gov. Brown's administration on the use of solar and renewable energy sources, as well as energy conservation are reviewed. Specific topics include: (1) political action; (2) business sense; (3) increased competition; (4) marketing; and (5) consumer protection. (MJJ)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70042741','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70042741"><span id="translatedtitle">A perspective on modern pesticides, pelagic fish declines, and unknown ecological resilience in highly managed <span class="hlt">ecosystems</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Scholz, Nathaniel L.; Fleishman, Erica; Brown, Larry; Werner, Inge; Johnson, Michael L.; Brooks, Marjorie L.; Mitchelmore, Carys L.; Schlenk, Daniel</p> <p>2012-01-01</p> <p>Pesticides applied on land are commonly transported by runoff or spray drift to aquatic <span class="hlt">ecosystems</span>, where they are potentially toxic to fishes and other nontarget organisms. Pesticides add to and interact with other stressors of <span class="hlt">ecosystem</span> processes, including surface-water diversions, losses of spawning and rearing habitats, nonnative species, and harmful algal blooms. Assessing the cumulative effects of pesticides on species or ecological functions has been difficult for historical, legal, conceptual, and practical reasons. To explore these challenges, we examine <span class="hlt">current</span>-use (modern) pesticides and their potential connections to the abundances of fishes in the San Francisco Estuary (<span class="hlt">California</span>). Declines in delta smelt (Hypomesus transpacificus), Chinook salmon (Oncorhynchus tshawytscha), and other species have triggered mandatory and expensive management actions in the urbanizing estuary and agriculturally productive Central Valley. Our inferences are transferable to other situations in which toxics may drive changes in ecological status and trends.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B51H0447H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B51H0447H"><span id="translatedtitle">Gaseous N fluxes in Mediterranean catchments: from low elevation chaparral to high elevation subalpine <span class="hlt">ecosystems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Homyak, P. M.; Sickman, J. O.</p> <p>2010-12-01</p> <p>Recent studies on gaseous N emissions from soils in semiarid <span class="hlt">ecosystems</span> have highlighted the importance of these losses for terrestrial <span class="hlt">ecosystems</span>. Losses tend to be relatively large during seasonal transitions where soil rewetting results in a “hot moment” of increased biological nitrification and gaseous N flux. To gain better understanding of chaparral N-dynamics, we measured NO and N2O emissions for one year in a chamise-dominated watershed located in the foothills of the Sierra Nevada (<span class="hlt">California</span>) whose previous nitrogen budget suggested net N retention (i.e., N inputs from atmospheric deposition > hydrologic outputs). We are also making additional gas flux measurements along an elevational gradient (300 to 2800 m) to determine if NO and N2O fluxes vary across <span class="hlt">ecosystems</span> (chaparral, mixed conifer, and subalpine) with varying capacity for assimilation of N deposition. Gaseous N fluxes measured at the chaparral site through the one-year period are in agreement with other studies of semiarid <span class="hlt">ecosystems</span> showing a pulse of NO (as high as 100 ng N m-2 s-1) immediately after rewetting of dry soils. The hot moment decreases by about half 24-hours after rewetting and decreases in magnitude with increasing frequency of rewetting episodes during the winter rainy season. As with other studies in semiarid <span class="hlt">ecosystems</span>, NO emissions decreased significantly with decreases in temperature averaging about 0.03 ng N m-2 s-1 and sometimes becoming negative during the cool winter. Measurements of the magnitude of the hot moment along the altitudinal gradient are in progress, and to the best of our knowledge, will be the first field measurement to include nitric oxide fluxes in subalpine <span class="hlt">ecosystems</span>. Based on our <span class="hlt">current</span> data, it is clear that gaseous N fluxes are an important component in N budgets for <span class="hlt">ecosystems</span> experiencing a strong seasonal transition in soil physico-chemical conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PalOc..30.1168T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PalOc..30.1168T"><span id="translatedtitle">The <span class="hlt">California</span> <span class="hlt">Current</span> System as a transmitter of millennial scale climate change on the northeastern Pacific margin from 10 to 50 ka</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taylor, M. A.; Hendy, I. L.; Pak, D. K.</p> <p>2015-09-01</p> <p>A high-resolution record of ?18O and Mg/Ca-based temperatures spanning 10-50 ka has been reconstructed from the Vancouver margin of the northeastern Pacific Ocean (MD02-2496) from two planktonic foraminiferal species, Neogloboquadrina pachyderma (s.) and Globigerina bulloides. While ?18Ocalcite appears synchronous with Dansgaard-Oeschger Interstadials throughout the record, millennial scale variability in sea surface temperatures and reconstructed ?18Oseawater are frequently out of phase with Greenland climate. Changes in water mass characteristics such as ?18Ocalcite and enriched ?15N events apparently responded to millennial-scale climate change during Marine Isotope Stage 3 (MIS 3), such that negative ?18Ocalcite excursions coincided with heavier ?15N. These water mass characteristic shifts are suggestive of the presence of surface water advected from the Eastern Tropical North Pacific by relative strengthening of the <span class="hlt">California</span> Undercurrent (CUC) bringing warm, salty tropical waters poleward. The linkage between the strength of the CUC on the NE Pacific margin and millennial-scale climate change may be related to increased sea surface heights off Central America as the Intertropical Convergence Zone shifted northward in response to changes in North Atlantic Ocean circulation. Poor correlations between proxies exist through late MIS 3 into MIS 2. Ice sheet growth could have disrupted the linkage between CUC and the NE Pacific margin as the Laurentide Ice sheet disrupted atmospheric circulation and the Cordilleran Ice Sheet increasingly influenced regional paleoceanography.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70024737','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70024737"><span id="translatedtitle">Fish communities of the Sacramento River Basin: Implications for conservation of native fishes in the Central Valley, <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>May, J.T.; Brown, L.R.</p> <p>2002-01-01</p> <p>The associations of resident fish communities with environmental variables and stream condition were evaluated at representative sites within the Sacramento River Basin, <span class="hlt">California</span> between 1996 and 1998 using multivariate ordination techniques and by calculating six fish community metrics. In addition, the results of the <span class="hlt">current</span> study were compared with recent studies in the San Joaquin River drainage to provide a wider perspective of the condition of resident fish communities in the Central Valley of <span class="hlt">California</span> as a whole. Within the Sacramento drainage, species distributions were correlated with elevational and substrate size gradients; however, the elevation of a sampling site was correlated with a suite of water-quality and habitat variables that are indicative of land use effects on physiochemical stream parameters. Four fish community metrics - percentage of native fish, percentage of intolerant fish, number of tolerant species, and percentage of fish with external anomalies - were responsive to environmental quality. Comparisons between the <span class="hlt">current</span> study and recent studies in the San Joaquin River drainage suggested that differences in water-management practices may have significant effects on native species fish community structure. Additionally, the results of the <span class="hlt">current</span> study suggest that index of biotic integrity-type indices can be developed for the Sacramento River Basin and possibly the entire Central Valley, <span class="hlt">California</span>. The protection of native fish communities in the Central Valley and other arid environments continues to be a conflict between human needs for water resources and the requirements of aquatic <span class="hlt">ecosystems</span>; preservation of these <span class="hlt">ecosystems</span> will require innovative management strategies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JGRC..109.1029M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JGRC..109.1029M"><span id="translatedtitle">Southern Antarctic Circumpolar <span class="hlt">Current</span> Front to the northeast of South Georgia: Horizontal advection of krill and its role in the <span class="hlt">ecosystem</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murphy, E. J.; Watkins, J. L.; Meredith, M. P.; Ward, P.; Trathan, P. N.; Thorpe, S. E.</p> <p>2004-01-01</p> <p>During December 2000 and January 2001 we conducted a high-resolution hydrographic and bioacoustic transect (RRS James Clark Ross cruise 57) that extended across the South Georgia shelf from close to Cumberland Bay, across the shelf break and slope and into the deep waters of the Georgia Basin beyond. We observed a high biomass of zooplankton between 53.8° and 53.4°S associated with the inshore, northwestward flow of the Southern Antarctic Circumpolar <span class="hlt">Current</span> Front (SACCF) that occurred in around 2500 m of water close to the base of the slope. There was very little zooplankton biomass present in the more offshore, eastward flowing waters where a second manifestation of the SACCF was also present on the section. The region of enhanced zooplankton biomass was over 50 km in horizontal extent with the highest densities (>10 g m-3) in the area of strongest flow (>35 cm s-1). The majority of the zooplankton present on the section was Antarctic krill and most of it occurred in the upper 100 m. The rate of physically mediated transport of Antarctic krill across the off-shelf sections (˜10 km) of the transect showed marked variation, with highest rates (>106 g s-1) associated with the northwestward flow of the SACCF. Farther offshore, where the krill biomass and flow rates were much reduced, the flux of krill was very low. The integrated horizontal flux of krill across the offshore sections was large (192 × 103 t d-1) and to the northwest. A second occupation of the transect showed that the krill flux is highly variable, and we discuss the various physical and biological factors that will generate such variability. We show that horizontal flux of krill in ocean <span class="hlt">currents</span> is a major factor in determining the abundance of krill around South Georgia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AAS...204.1206N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AAS...204.1206N"><span id="translatedtitle">Astronomical <span class="hlt">Ecosystems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neuenschwander, D. E.; Finkenbinder, L. R.</p> <p>2004-05-01</p> <p>Just as quetzals and jaguars require specific ecological habitats to survive, so too must planets occupy a tightly constrained astronomical habitat to support life as we know it. With this theme in mind we relate the transferable features of our elementary astronomy course, "The Astronomical Basis of Life on Earth." Over the last five years, in a team-taught course that features a spring break field trip to Costa Rica, we have introduced astronomy through "astronomical <span class="hlt">ecosystems</span>," emphasizing astronomical constraints on the prospects for life on Earth. Life requires energy, chemical elements, and long timescales, and we emphasize how cosmological, astrophysical, and geological realities, through stabilities and catastrophes, create and eliminate niches for biological life. The linkage between astronomy and biology gets immediate and personal: for example, studies in solar energy production are followed by hikes in the forest to examine the light-gathering strategies of photosynthetic organisms; a lesson on tides is conducted while standing up to our necks in one on a Pacific beach. Further linkages between astronomy and the human timescale concerns of biological diversity, cultural diversity, and environmental sustainability are natural and direct. Our experience of teaching "astronomy as habitat" strongly influences our "Astronomy 101" course in Oklahoma as well. This "inverted astrobiology" seems to transform our student's outlook, from the universe being something "out there" into something "we're in!" We thank the SNU Science Alumni support group "The Catalysts," and the SNU Quetzal Education and Research Center, San Gerardo de Dota, Costa Rica, for their support.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/885687','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/885687"><span id="translatedtitle">Sustaining the Landscape: A Method for Comparing <span class="hlt">Current</span> and Desired Future Conditions of Forest <span class="hlt">Ecosystems</span> in the North Cumberland Plateau and Mountains</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Druckenbrod, D.L.</p> <p>2004-12-22</p> <p>This project initiates an integrated-landscape conservation approach within the Northern Cumberlands Project Area in Tennessee and Kentucky. The mixed mesophytic forests within the Cumberland Plateau and Mountains are among the most diverse in North America; however, these forests have been impacted by and remain threatened from changes in land use across this landscape. The integrated-landscape conservation approach presented in this report outlines a sequence of six conservation steps. This report considers the first three of these steps in two, successive stages. Stage 1 compares desired future conditions (DFCs) and <span class="hlt">current</span> prevailing conditions (CPCs) at the landscape-scale utilizing remote sensing imagery, remnant forests, and descriptions of historical forest types within the Cumberland Plateau. Subsequently, Stage 2 compares DFCs and CPCs for at-risk forest types identified in Stage 1 utilizing structural, compositional, or functional attributes from USFS Forest Inventory and Analysis data. Ecological indicators will be developed from each stage that express the gaps between these two realizations of the landscape. The results from these first three steps will directly contribute to the final three steps of the integrated-landscape conservation approach by providing guidance for the generation of new conservation strategies in the Northern Cumberland Plateau and Mountains.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23886247','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23886247"><span id="translatedtitle">Refocusing Mussel Watch on contaminants of emerging concern (CECs): the <span class="hlt">California</span> pilot study (2009-10).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maruya, Keith A; Dodder, Nathan G; Schaffner, Rebecca A; Weisberg, Stephen B; Gregorio, Dominic; Klosterhaus, Susan; Alvarez, David A; Furlong, Edward T; Kimbrough, Kimani L; Lauenstein, Gunnar G; Christensen, John D</p> <p>2014-04-30</p> <p>To expand the utility of the Mussel Watch Program, local, regional and state agencies in <span class="hlt">California</span> partnered with NOAA to design a pilot study that targeted contaminants of emerging concern (CECs). Native mussels (Mytilus spp.) from 68 stations, stratified by land use and discharge scenario, were collected in 2009-10 and analyzed for 167 individual pharmaceuticals, industrial and commercial chemicals and <span class="hlt">current</span> use pesticides. Passive sampling devices (PSDs) and caged Mytilus were co-deployed to expand the list of CECs, and to assess the ability of PSDs to mimic bioaccumulation by Mytilus. A performance-based quality assurance/quality control (QA/QC) approach was developed to ensure a high degree of data quality, consistency and comparability. Data management and analysis were streamlined and standardized using automated software tools. This pioneering study will help shape future monitoring efforts in <span class="hlt">California</span>'s coastal <span class="hlt">ecosystems</span>, while serving as a model for monitoring CECs within the region and across the nation. PMID:23886247</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B51H0451V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B51H0451V"><span id="translatedtitle">A 115-year ?15N record of cumulative nitrogen pollution in <span class="hlt">California</span> serpentine grasslands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vallano, D.; Zavaleta, E. S.</p> <p>2010-12-01</p> <p>Until the 1980s, <span class="hlt">Californias</span> biodiverse serpentine grasslands were threatened primarily by development and protected by reserve creation. However, nitrogen (N) fertilization due to increasing fossil fuel emissions in the expanding Bay Area is thought to be contributing to rapid, recent invasion of these <span class="hlt">ecosystems</span> by exotic annual grasses that are displacing rare and endemic serpentine species. Documenting the cumulative effects of N deposition in this <span class="hlt">ecosystem</span> can direct policy and management actions to mitigate the role of N deposition in its transformation. Natural abundance stable isotopes of N in vegetation have been increasingly used as bio-indicators of N deposition patterns and subsequent changes to plant N cycling and assimilation. However, the long-term record of atmospheric reactive N enrichment and the resulting changes in <span class="hlt">ecosystem</span> N dynamics have yet to be adequately reconstructed in many <span class="hlt">ecosystems</span>. Museum archives of vascular plant tissue are valuable sources of materials to reconstruct temporal and spatial isotopic patterns of N inputs to <span class="hlt">ecosystems</span>. Here, we present N stable isotope data from archived and <span class="hlt">current</span> specimens of an endemic <span class="hlt">California</span> serpentine grassland species, leather oak (Quercus durata), since 1895 across the greater San Francisco Bay region. We measured spatial and temporal trends in stable isotope composition (?15N and ?13C) and concentration (%N and %C) of historical and <span class="hlt">current</span> samples of leather oak leaves from sites within the Bay Area, impacted by increasing development, and sites northeast of the Bay Area, with significantly lower rates of urbanization and industrialization. Specifically, we sampled dry museum and fresh leaf specimens from serpentine sites within Lake (n=27) and Santa Clara (n=30) counties dating from 1895 to 2010. Leaf ?15N values were stable from 1895 to the 1950s and then decreased strongly throughout the last 50 years as fossil fuel emissions rapidly increased in the Bay Area, indicating that N pollution is being retained in serpentine grassland <span class="hlt">ecosystems</span>. Leaf ?15N values in the high-deposition region declined at a rate of -0.041 yr-1, while leaf ?15N values in the low-deposition region did not show a strong pattern. In both regions, leaf ?13C values declined through time as atmospheric CO2 concentrations increased in response to fossil fuel combustion (the Suess effect). Leaf %N and %C values did not present any clear patterns at sites within or outside of the Bay Area. We conclude that using natural abundance stable isotope values in leaves can indicate variation in N pollution inputs across wide spatial and temporal scales and that archived plant samples can provide valuable baselines against which to assess changes in regional N cycling and subsequent ecological impacts on vegetation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/fs20123132','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/fs20123132"><span id="translatedtitle">Understanding pesticides in <span class="hlt">California</span>'s Delta</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kuivila, Kathryn M.; Orlando, James L.</p> <p>2012-01-01</p> <p>The Sacramento-San Joaquin River Delta (Delta) is the hub of <span class="hlt">Californias</span> water system and also an important habitat for imperiled fish and wildlife. Aquatic organisms are exposed to mixtures of pesticides that flow through the maze of Delta water channels from sources including agricultural, landscape, and urban pest-control applications. While we do not know all of the effects pesticides have on the <span class="hlt">ecosystem</span>, there is evidence that they cause some damage to organisms in the Delta. Decades of USGS research have provided a good understanding of when, where, and how pesticides enter the Delta. However, pesticide use is continually changing. New field studies and methods are needed so that scientists can analyze which pesticides are present in the Delta, and at what concentrations, enabling them to estimate exposure and ultimate effects on organisms. Continuing research will provide resource managers and stakeholders with crucial information to manage the Delta wisely.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70168703','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70168703"><span id="translatedtitle">Endangered species management and <span class="hlt">ecosystem</span> restoration: Finding the common ground</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Casazza, Michael L.; Overton, Cory T.; Bui, Thuy-Vy D.; Hull, Joshua M.; Albertson, Joy D.; Bloom, Valary K.; Bobzien, Steven; McBroom, Jennifer; Latta, Marilyn; Olofson, Peggy; Rohmer, Tobias M.; Schwarzbach, Steven E.; Strong, Donald R.; Grijalva, Erik; Wood, Julian K.; Skalos, Shannon; Takekawa, John</p> <p>2016-01-01</p> <p>Management actions to protect endangered species and conserve <span class="hlt">ecosystem</span> function may not always be in precise alignment. Efforts to recover the <span class="hlt">California</span> Ridgway’s Rail (Rallus obsoletus obsoletus; hereafter, <span class="hlt">California</span> rail), a federally and state-listed species, and restoration of tidal marsh <span class="hlt">ecosystems</span> in the San Francisco Bay estuary provide a prime example of habitat restoration that has conflicted with species conservation. On the brink of extinction from habitat loss and degradation, and non-native predators in the 1990s, <span class="hlt">California</span> rail populations responded positively to introduction of a non-native plant, Atlantic cordgrass (Spartina alterniflora). <span class="hlt">California</span> rail populations were in substantial decline when the non-native Spartina was initially introduced as part of efforts to recover tidal marshes. Subsequent hybridization with the native Pacific cordgrass (Spartina foliosa) boosted <span class="hlt">California</span> rail populations by providing greater cover and increased habitat area. The hybrid cordgrass (S. alterniflora × S. foliosa) readily invaded tidal mudflats and channels, and both crowded out native tidal marsh plants and increased sediment accretion in the marsh plain. This resulted in modification of tidal marsh geomorphology, hydrology, productivity, and species composition. Our results show that denser <span class="hlt">California</span> rail populations occur in invasive Spartina than in native Spartina in San Francisco Bay. Herbicide treatment between 2005 and 2012 removed invasive Spartina from open intertidal mud and preserved foraging habitat for shorebirds. However, removal of invasive Spartina caused substantial decreases in <span class="hlt">California</span> rail populations. Unknown facets of <span class="hlt">California</span> rail ecology, undesirable interim stages of tidal marsh restoration, and competing management objectives among stakeholders resulted in management planning for endangered species or <span class="hlt">ecosystem</span> restoration that favored one goal over the other. We have examined this perceived conflict and propose strategies for moderating harmful effects of restoration while meeting the needs of both endangered species and the imperiled native marsh <span class="hlt">ecosystem</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=188338&keyword=mechanics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=54221219&CFTOKEN=51667831','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=188338&keyword=mechanics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=54221219&CFTOKEN=51667831"><span id="translatedtitle">Fishing for Novel Approaches to <span class="hlt">Ecosystem</span> Service Forecasts</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The <span class="hlt">ecosystem</span> service concept provides a powerful framework for conserving species and the environments they depend upon. Describing <span class="hlt">current</span> distributions of <span class="hlt">ecosystem</span> services and forecasting their future distributions have therefore become central objectives in many conservati...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70118896','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70118896"><span id="translatedtitle">Valuation of rangeland <span class="hlt">ecosystem</span> services</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gascoigne, W.R.</p> <p>2011-01-01</p> <p>Economic valuation lends itself well to the anthropocentric orientation of <span class="hlt">ecosystem</span> services. An economic perspective on <span class="hlt">ecosystems</span> portrays them as natural assets providing a flow of goods and services valuable to individuals and society collectively. A few examples include the purification of drinking water, reduced risk from flooding and other extreme events, pollination of agricultural crops, climate regulation, and recreation opportunities from plant and animal habitat maintenance, among many others. Once these goods and services are identified and quantified, they can be monetized to complete the valuation process. The monetization of <span class="hlt">ecosystem</span> goods and services (in the form of dollars) provides a common metric that allows for cross-comparison of attributes and evaluation of differing ecological scenarios. Complicating the monetization process is the fact that most of these goods and services are public and non-market in nature; meaning they are non-rival and non-exclusive and are typically not sold in a traditional market setting where monetary values are revealed. Instead, one must employ non-market valuation techniques, with primary valuation methods typically being very time and resource consuming, intimidating to non-economists, and often impractical. For these reasons, benefit transfer methods have gained popularity. This methodology harnesses the primary collection results of existing studies to make inferences about the economic values of non-market goods and services at an alternative policy site (in place and/or in time). For instance, if a primary valuation study on oak reestablishment on rangelands in southern <span class="hlt">California</span> yielded a value of $30 per-acre associated with water regulation, this result can be transferred, with some adjustments, to say something about the value of an acre of oaks on rangelands in northern portions of the state. The economic valuation of rangeland <span class="hlt">ecosystem</span> services has many roles. Economic values may be used as input into analyzing the costs and benefits associated with policies being proposed, or possibly already implemented. For example, with monetized values acting as a common metric, one could compare the 'benefits' of converting a rangeland <span class="hlt">ecosystem</span> for commercial development (perhaps estimated at the market value of the developed land) with the foregone <span class="hlt">ecosystem</span> service values (in addition to any land income lost) resulting from that land conversion. Similarly, <span class="hlt">ecosystem</span> service values can be used to determine the level of return on an investment. rhis is a primary objective for private land conservation organizations who typically have very limited resources. <span class="hlt">Ecosystem</span> service valuation can also have a role in damage assessments from incidents that require compensation such as oil spills. Additionally, valuation can be very informative when investigating regulatory programs that trade ecological assets such as wetland mitigation programs. Typically these programs are based simply on an 'acre for acre' criterion, and do not take into consideration varying welfare values associated with that <span class="hlt">ecosystem</span>. Lastly, and most fundamental, <span class="hlt">ecosystem</span> service valuation serves as a recognition tool for people of all backgrounds. Identifying and valuing <span class="hlt">ecosystem</span> goods and services on rangelands brings to light the value these natural assets have to human welfare that often remain hidden do to their public and non-market attributes. This type of recognition is vital to the preservation of rangeland <span class="hlt">ecosystems</span> in the future and the many ecological benefits they provide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25733875','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25733875"><span id="translatedtitle">Anthropogenic warming has increased drought risk in <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Diffenbaugh, Noah S; Swain, Daniel L; Touma, Danielle</p> <p>2015-03-31</p> <p><span class="hlt">California</span> is <span class="hlt">currently</span> in the midst of a record-setting drought. The drought began in 2012 and now includes the lowest calendar-year and 12-mo precipitation, the highest annual temperature, and the most extreme drought indicators on record. The extremely warm and dry conditions have led to acute water shortages, groundwater overdraft, critically low streamflow, and enhanced wildfire risk. Analyzing historical climate observations from <span class="hlt">California</span>, we find that precipitation deficits in <span class="hlt">California</span> were more than twice as likely to yield drought years if they occurred when conditions were warm. We find that although there has not been a substantial change in the probability of either negative or moderately negative precipitation anomalies in recent decades, the occurrence of drought years has been greater in the past two decades than in the preceding century. In addition, the probability that precipitation deficits co-occur with warm conditions and the probability that precipitation deficits produce drought have both increased. Climate model experiments with and without anthropogenic forcings reveal that human activities have increased the probability that dry precipitation years are also warm. Further, a large ensemble of climate model realizations reveals that additional global warming over the next few decades is very likely to create ∼ 100% probability that any annual-scale dry period is also extremely warm. We therefore conclude that anthropogenic warming is increasing the probability of co-occurring warm-dry conditions like those that have created the acute human and <span class="hlt">ecosystem</span> impacts associated with the "exceptional" 2012-2014 drought in <span class="hlt">California</span>. PMID:25733875</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4386330','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4386330"><span id="translatedtitle">Anthropogenic warming has increased drought risk in <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Diffenbaugh, Noah S.; Swain, Daniel L.; Touma, Danielle</p> <p>2015-01-01</p> <p><span class="hlt">California</span> is <span class="hlt">currently</span> in the midst of a record-setting drought. The drought began in 2012 and now includes the lowest calendar-year and 12-mo precipitation, the highest annual temperature, and the most extreme drought indicators on record. The extremely warm and dry conditions have led to acute water shortages, groundwater overdraft, critically low streamflow, and enhanced wildfire risk. Analyzing historical climate observations from <span class="hlt">California</span>, we find that precipitation deficits in <span class="hlt">California</span> were more than twice as likely to yield drought years if they occurred when conditions were warm. We find that although there has not been a substantial change in the probability of either negative or moderately negative precipitation anomalies in recent decades, the occurrence of drought years has been greater in the past two decades than in the preceding century. In addition, the probability that precipitation deficits co-occur with warm conditions and the probability that precipitation deficits produce drought have both increased. Climate model experiments with and without anthropogenic forcings reveal that human activities have increased the probability that dry precipitation years are also warm. Further, a large ensemble of climate model realizations reveals that additional global warming over the next few decades is very likely to create ∼100% probability that any annual-scale dry period is also extremely warm. We therefore conclude that anthropogenic warming is increasing the probability of co-occurring warm–dry conditions like those that have created the acute human and <span class="hlt">ecosystem</span> impacts associated with the “exceptional” 2012–2014 drought in <span class="hlt">California</span>. PMID:25733875</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70046245','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70046245"><span id="translatedtitle">Columbia River Estuary <span class="hlt">Ecosystem</span> Classification <span class="hlt">Ecosystem</span> Complex</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cannon, Charles M.; Ramirez, Mary F.; Heatwole, Danelle W.; Burke, Jennifer L.; Simenstad, Charles A.; O'Connor, Jim E.; Marcoe, Keith Marcoe</p> <p>2012-01-01</p> <p>Estuarine <span class="hlt">ecosystems</span> are controlled by a variety of processes that operate at multiple spatial and temporal scales. Understanding the hierarchical nature of these processes will aid in prioritization of restoration efforts. This hierarchical Columbia River Estuary <span class="hlt">Ecosystem</span> Classification (henceforth "Classification") of the Columbia River estuary is a spatial database of the tidally-influenced reaches of the lower Columbia River, the tidally affected parts of its tributaries, and the landforms that make up their floodplains for the 230 kilometers between the Pacific Ocean and Bonneville Dam. This work is a collaborative effort between University of Washington School of Aquatic and Fishery Sciences (henceforth "UW"), U.S. Geological Survey (henceforth "USGS"), and the Lower Columbia Estuary Partnership (henceforth "EP"). Consideration of geomorphologic processes will improve the understanding of controlling physical factors that drive <span class="hlt">ecosystem</span> evolution along the tidal Columbia River. The Classification is organized around six hierarchical levels, progressing from the coarsest, regional scale to the finest, localized scale: (1) <span class="hlt">Ecosystem</span> Province; (2) Ecoregion; (3) Hydrogeomorphic Reach; (4) <span class="hlt">Ecosystem</span> Complex; (5) Geomorphic Catena; and (6) Primary Cover Class. For Levels 4 and 5, we mapped landforms within the Holocene floodplain primarily by visual interpretation of Light Detection and Ranging (LiDAR) topography supplemented with aerial photographs, Natural Resources Conservation Service (NRCS) soils data, and historical maps. Mapped landforms are classified as to their <span class="hlt">current</span> geomorphic function, the inferred process regime that formed them, and anthropogenic modification. Channels were classified primarily by a set of depth-based rules and geometric relationships. Classification Level 5 floodplain landforms ("geomorphic catenae") were further classified based on multivariate analysis of land-cover within the mapped landform area and attributed as "sub-catena". The extent of detailed mapping is the interpreted Holocene geologic floodplain of the tidal Columbia River and its tributaries to the estimated head of tide. The extent of this dataset also includes tributary valleys that are not mapped in detail. The upstream extents of tributary valleys are an estimation of the limit of Columbia River influence and are for use as containers in future analyses. The geologic floodplain is the geomorphic surface that is actively accumulating sediment through occasional overbank deposition. Most features within the geologic floodplain are considered to be formed during the recent (Holocene-epoch) climatic regime. There are bedrock and pre-Holocene sedimentary deposits included where they are surrounded by Holocene sediment accumulations or have been shaped by Holocene floods. In some places, Holocene landforms such as landslides, tributary fans, and coastal dunes are mapped that extend outside of the modern floodplain. This map is not a floodplain hazard map or delineation of actual flood boundaries. Although wetlands are included in the Classification, they are based on different criteria than jurisdictional wetlands. The extent of mapping may differ from the actual limit of tidal influence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15201908','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15201908"><span id="translatedtitle">Upwelling-driven nearshore hypoxia signals <span class="hlt">ecosystem</span> and oceanographic changes in the northeast Pacific.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Grantham, Brian A; Chan, Francis; Nielsen, Karina J; Fox, David S; Barth, John A; Huyer, Adriana; Lubchenco, Jane; Menge, Bruce A</p> <p>2004-06-17</p> <p>Seasonal development of dissolved-oxygen deficits (hypoxia) represents an acute system-level perturbation to ecological dynamics and fishery sustainability in coastal <span class="hlt">ecosystems</span> around the globe. Whereas anthropogenic nutrient loading has increased the frequency and severity of hypoxia in estuaries and semi-enclosed seas, the occurrence of hypoxia in open-coast upwelling systems reflects ocean conditions that control the delivery of oxygen-poor and nutrient-rich deep water onto continental shelves. Upwelling systems support a large proportion of the world's fisheries, therefore understanding the links between changes in ocean climate, upwelling-driven hypoxia and ecological perturbations is critical. Here we report on the unprecedented development of severe inner-shelf (<70 m) hypoxia and resultant mass die-offs of fish and invertebrates within the <span class="hlt">California</span> <span class="hlt">Current</span> System. In 2002, cross-shelf transects revealed the development of abnormally low dissolved-oxygen levels as a response to anomalously strong flow of subarctic water into the <span class="hlt">California</span> <span class="hlt">Current</span> System. Our findings highlight the sensitivity of inner-shelf <span class="hlt">ecosystems</span> to variation in ocean conditions, and the potential impacts of climate change on marine communities. PMID:15201908</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70157548','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70157548"><span id="translatedtitle">Re-establishing marshes can return carbon sink functions to a <span class="hlt">current</span> carbon source in the Sacramento-San Joaquin Delta of <span class="hlt">California</span>, USA</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Miller, Robin L.; Fujii, Roger</p> <p>2011-01-01</p> <p>The Sacramento-San Joaquin Delta in <span class="hlt">California</span> was an historic, vast inland freshwater wetland, where organic soils almost 20 meters deep formed over the last several millennia as the land surface elevation of marshes kept pace with sea level rise. A system of levees and pumps were installed in the late 1800s and early 1900s to drain the land for agricultural use. Since then, land surface has subsided more than 7 meters below sea level in some areas as organic soils have been lost to aerobic decomposition. As land surface elevations decrease, costs for levee maintenance and repair increase, as do the risks of flooding. Wetland restoration can be a way to mitigate subsidence by re-creating the environment in which the organic soils developed. A preliminary study of the effect of hydrologic regime on carbon cycling conducted on Twitchell Island during the mid-1990s showed that continuous, shallow flooding allowing for the growth of emergent marsh vegetation re-created a wetland environment where carbon preservation occurred. Under these conditions annual plant biomass carbon inputs were high, and microbial decomposition was reduced. Based on this preliminary study, the U.S. Geological Survey re-established permanently flooded wetlands in fall 1997, with shallow water depths of 25 and 55 centimeters, to investigate the potential to reverse subsidence of delta islands by preserving and accumulating organic substrates over time. Ten years after flooding, elevation gains from organic matter accumulation in areas of emergent marsh vegetation ranged from almost 30 to 60 centimeters, with average annual carbon storage rates approximating 1 kg/m2, while areas without emergent vegetation cover showed no significant change in elevation. Differences in accretion rates within areas of emergent marsh vegetation appeared to result from temporal and spatial variability in hydrologic factors and decomposition rates in the wetlands rather than variability in primary production. Decomposition rates were related to differences in hydrologic conditions, including water temperature, pH, dissolved oxygen concentration, and availability of alternate electron acceptors. The study showed that marsh re-establishment with permanent, low energy, shallow flooding can limit oxidation of organic soils, thus, effectively turning subsiding land from atmospheric carbon sources to carbon sinks, and at the same time reducing flood vulnerability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/pp/pp1692/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/pp/pp1692/"><span id="translatedtitle">Eruptive History and Chemical Evolution of the Precaldera and Postcaldera Basalt-Dacite Sequences, Long Valley, <span class="hlt">California</span>: Implications for Magma Sources, <span class="hlt">Current</span> Seismic Unrest, and Future Volcanism</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bailey, Roy A.</p> <p>2004-01-01</p> <p>The Long Valley Volcanic Field in east-central <span class="hlt">California</span> straddles the East Sierran frontal fault zone, overlapping the Sierra Nevada and western Basin and Range Provinces. The volcanic field overlies a mature mid-Tertiary erosional surface that truncates a basement composed mainly of Mesozoic plutons and associated roof pendants of Mesozoic metavolcanic and Paleozoic metasedimentary rocks. Long Valley volcanism began about 4 Ma during Pliocene time and has continued intermittently through the Holocene. The volcanism is separable into two basalt-rhyolite episodes: (1) an earlier, precaldera episode related to Long Valley Caldera that climaxed with eruption of the Bishop Tuff and collapse of the caldera; and (2) a later, postcaldera episode structurally related to the north-south-trending Mono-Inyo Craters fissure system, which extends from the vicinity of Mammoth Mountain northward through the west moat of the caldera to Mono Lake. Eruption of the basalt-dacite sequence of the precaldera basalt-rhyolite episode peaked volumetrically between 3.8 and 2.5 Ma; few basalts were erupted during the following 1.8 m.y. (2.5?0.7 Ma). Volcanism during this interval was dominated by eruption of the voluminous rhyolites of Glass Mountain (2.2?0.8 Ma) and formation of the Bishop Tuff magma chamber. Catastrophic rupture of the roof of this magma chamber caused eruption of the Bishop Tuff and collapse of Long Valley Caldera (760 ka), after which rhyolite eruptions resumed on the subsided caldera floor. The earliest postcaldera rhyolite flows (700?500 ka) contain quenched globular basalt enclaves (mafic magmatic inclusions), indicating that basaltic magma had reentered shallow parts of the magmatic system after a 1.8-m.y. hiatus. Later, at about 400 ka, copious basalts, as well as dacites, began erupting from vents mainly in the west moat of the caldera. These later eruptions initiated the postcaldera basalt-rhyolite episode related to the Mono-Inyo Craters fissure system, which has been active through late Pleistocene and Holocene time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=simulation+AND+history&pg=6&id=ED515651','ERIC'); return false;" href="http://eric.ed.gov/?q=simulation+AND+history&pg=6&id=ED515651"><span id="translatedtitle">Pathways for School Finance in <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rose, Heather; Sonstelie, Jon; Weston, Margaret</p> <p>2010-01-01</p> <p><span class="hlt">California</span>'s budget crisis has diminished educational resources for the state's <span class="hlt">current</span> cohort of public school students. Because school districts have less revenue, class sizes are larger and struggling students receive less assistance. Under these circumstances, it seems beside the point to suggest that <span class="hlt">California</span> should begin planning for the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=college+AND+groups+AND+leaders&pg=6&id=EJ981001','ERIC'); return false;" href="http://eric.ed.gov/?q=college+AND+groups+AND+leaders&pg=6&id=EJ981001"><span id="translatedtitle">Multicultural Graduation Requirements among <span class="hlt">California</span>'s Community Colleges</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hess, Shelly L.; Uerling, Donald F.; Piland, William E.</p> <p>2012-01-01</p> <p>This examination of the <span class="hlt">current</span> status of multicultural education among <span class="hlt">California</span> community colleges emerged from a perspective that the inclusion of multicultural education has become a major goal of <span class="hlt">California</span>'s leaders within the past five years. The literature revealed minority students tend to have lower retention rates because they become</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=199527&keyword=High+AND+tide&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=63707502&CFTOKEN=52180903','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=199527&keyword=High+AND+tide&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=63707502&CFTOKEN=52180903"><span id="translatedtitle">Measuring the contribution of benthic <span class="hlt">ecosystem</span> engineering species to the <span class="hlt">ecosystem</span> services of an estuary: A case study of burrowing shrimps in Yaquina Estuary, Oregon</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Burrowing shrimps are regarded as <span class="hlt">ecosystem</span> engineering species in many coastal <span class="hlt">ecosystems</span> worldwide, including numerous estuaries of the west coast of North America (Baja <span class="hlt">California</span> to British Columbia). In estuaries of the U.S. Pacific Northwest, two species of large burrowing...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=205451&keyword=High+AND+tide&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=63707502&CFTOKEN=52180903','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=205451&keyword=High+AND+tide&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=63707502&CFTOKEN=52180903"><span id="translatedtitle">Measuring the contribution of benthic <span class="hlt">ecosystem</span> engineering species to the <span class="hlt">ecosystem</span> services of an estuary: A case study of burrowing shrimps in Yaquina Estuary, Oregon - April 2009</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Burrowing shrimps are regarded as <span class="hlt">ecosystem</span> engineering species in many coastal <span class="hlt">ecosystems</span> worldwide, including numerous estuaries of the west coast of North America (Baja <span class="hlt">California</span> to British Columbia). In estuaries of the U.S. Pacific Northwest, two species of large burrowing...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUSMOS22B..03G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSMOS22B..03G"><span id="translatedtitle">Oceanographic Observations in the Mexican Pacific Ocean to Understand the Pelagic <span class="hlt">Ecosystem</span> Response to the Climate Variability and Climate Change (1997-2006)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gaxiola-Castro, G.; Lavaniegos, B.; Durazo, R.; Lara-Lara, R.; Aguirre-Gomez, R.; Gomez-Valdez, J.; Carriquiry, J.; Pares-Sierra, A.</p> <p>2007-05-01</p> <p>In the northeastern Pacific Ocean we are developing a long-term oceanographic program (IMECOCAL) to understand the pelagic <span class="hlt">ecosystem</span> response to the climate variability and climate change. The IMECOCAL program began in October 1997, and we are expecting to continue until at least 2008 year, with the CONACYT (Mexican Council of Science and Technology) and CICESE supports. The IMECOCAL program is quarterly visiting an oceanographic area of the southern <span class="hlt">California</span> <span class="hlt">Current</span> region off Baja <span class="hlt">California</span>, with approximately 80 hydrographic stations. Also, we are planning two continuous sampling sites, one in northern, and another in the south of the Baja <span class="hlt">California</span> Peninsula. One of our main goals is understand the interannual variability of the physical-biological interactions in the pelagic <span class="hlt">ecosystem</span>, with the study of major oceanic physical processes, together with temporal changes of temperature and salinity in the water column, and their relationships with plankton fluctuations. Also, we are searching the long term signature of the climate change over the ocean, with sediments analysis collected at San Lazaro Basin, one of the few anoxic basins of the eastern Pacific Ocean. The program will be modeled the effects of climate variability on the structure of the pelagic <span class="hlt">ecosystem</span>, selecting some planktonic key species. Also, using hydrographic and remote sensed information (SST, Color, and SSH), global models will be feed with local estimated phytoplankton photosynthetic parameters, to realize statistical analyses in order to define spatial and temporal variability of plankton biomass and primary production in this area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70033696','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70033696"><span id="translatedtitle">Are hotspots of evolutionary potential adequately protected in southern <span class="hlt">California</span>?</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Vandergast, A.G.; Bohonak, A.J.; Hathaway, S.A.; Boys, J.; Fisher, R.N.</p> <p>2008-01-01</p> <p>Reserves are often designed to protect rare habitats, or "typical" exemplars of ecoregions and geomorphic provinces. This approach focuses on <span class="hlt">current</span> patterns of organismal and <span class="hlt">ecosystem</span>-level biodiversity, but typically ignores the evolutionary processes that control the gain and loss of biodiversity at these and other levels (e.g., genetic, ecological). In order to include evolutionary processes in conservation planning efforts, their spatial components must first be identified and mapped. We describe a GIS-based approach for explicitly mapping patterns of genetic divergence and diversity for multiple species (a "multi-species genetic landscape"). Using this approach, we analyzed mitochondrial DNA datasets from 21 vertebrate and invertebrate species in southern <span class="hlt">California</span> to identify areas with common phylogeographic breaks and high intrapopulation diversity. The result is an evolutionary framework for southern <span class="hlt">California</span> within which patterns of genetic diversity can be analyzed in the context of historical processes, future evolutionary potential and <span class="hlt">current</span> reserve design. Our multi-species genetic landscapes pinpoint six hotspots where interpopulation genetic divergence is consistently high, five evolutionary hotspots within which genetic connectivity is high, and three hotspots where intrapopulation genetic diversity is high. These 14 hotspots can be grouped into eight geographic areas, of which five largely are unprotected at this time. The multi-species genetic landscape approach may provide an avenue to readily incorporate measures of evolutionary process into GIS-based systematic conservation assessment and land-use planning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23233477','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23233477"><span id="translatedtitle">Brown v. Plata: prison overcrowding in <span class="hlt">California</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Newman, William J; Scott, Charles L</p> <p>2012-01-01</p> <p><span class="hlt">California</span>'s prisons are <span class="hlt">currently</span> designed to house approximately 85,000 inmates. At the time of the U.S. Supreme Court's 2011 decision in Brown v. Plata, the <span class="hlt">California</span> prison system housed nearly twice that many (approximately 156,000 inmates). The Supreme Court held that <span class="hlt">California</span>'s prison system violated inmates' Eighth Amendment rights. The Court upheld a three-judge panel's order to decrease the population of <span class="hlt">California</span>'s prisons by an estimated 46,000 inmates. They determined that overcrowding was the primary cause of the inmates' inadequate medical and mental health care. As a result, the <span class="hlt">California</span> Department of Corrections and Rehabilitation (CDCR) has been working to redistribute inmates and parolees safely and decrease the overall population to the mandated levels. These large-scale adjustments to <span class="hlt">California</span>'s penal system create potential opportunities to study the long-term effects on affected inmates. PMID:23233477</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70026823','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70026823"><span id="translatedtitle"><span class="hlt">California</span> earthquake history</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Toppozada, T.; Branum, D.</p> <p>2004-01-01</p> <p>This paper presents an overview of the advancement in our knowledge of <span class="hlt">California</span>'s earthquake history since ??? 1800, and especially during the last 30 years. We first review the basic statewide research on earthquake occurrences that was published from 1928 through 2002, to show how the <span class="hlt">current</span> catalogs and their levels of completeness have evolved with time. Then we review some of the significant new results in specific regions of <span class="hlt">California</span>, and some of what remains to be done. Since 1850, 167 potentially damaging earthquakes of M ??? 6 or larger have been identified in <span class="hlt">California</span> and its border regions, indicating an average rate of 1.1 such events per year. Table I lists the earthquakes of M ??? 6 to 6.5 that were also destructive since 1812 in <span class="hlt">California</span> and its border regions, indicating an average rate of one such event every ??? 5 years. Many of these occurred before 1932 when epicenters and magnitudes started to be determined routinely using seismographs in <span class="hlt">California</span>. The number of these early earthquakes is probably incomplete in sparsely populated remote parts of <span class="hlt">California</span> before ??? 1870. For example, 6 of the 7 pre-1873 events in table I are of M ??? 7, suggesting that other earthquakes of M 6.5 to 6.9 occurred but were not properly identified, or were not destructive. The epicenters and magnitudes (M) of the pre-instrumental earthquakes were determined from isoseismal maps that were based on the Modified Mercalli Intensity of shaking (MMI) at the communities that reported feeling the earthquakes. The epicenters were estimated to be in the regions of most intense shaking, and values of M were estimated from the extent of the areas shaken at various MMI levels. MMI VII or greater shaking is the threshold of damage to weak buildings. Certain areas in the regions of Los Angeles, San Francisco, and Eureka were each shaken repeatedly at MMI VII or greater at least six times since ??? 1812, as depicted by Toppozada and Branum (2002, fig. 19).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=266779','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=266779"><span id="translatedtitle">Postharvest dried apricot color degradation of three <span class="hlt">California</span> apricot accessions</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p><span class="hlt">Californias</span> dry apricot industry has provided high quality products for nearly a century, annually accounting for approximately 20% of available tonnage. The Patterson cultivar <span class="hlt">currently</span> dominates <span class="hlt">California</span> dry apricot sales, but the cultivar is not without faults. Newer cultivars and breeding a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Johnson&pg=6&id=ED515619','ERIC'); return false;" href="http://eric.ed.gov/?q=Johnson&pg=6&id=ED515619"><span id="translatedtitle">Pathways for School Finance in <span class="hlt">California</span>. Technical Appendix</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rose, Heather; Sonstelie, Jon; Weston, Margaret</p> <p>2010-01-01</p> <p>This is a technical appendix for the report, "Pathways for School Finance in <span class="hlt">California</span>" (ED515651). "Pathways for School Finance in <span class="hlt">California</span>" simulates alternatives to <span class="hlt">California</span>'s <span class="hlt">current</span> school finance system. This appendix provides more information about the revenues used in those simulations. The first section describes the districts and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=moral+AND+mandates&pg=4&id=EJ557608','ERIC'); return false;" href="http://eric.ed.gov/?q=moral+AND+mandates&pg=4&id=EJ557608"><span id="translatedtitle">Character Education Comes to <span class="hlt">California</span>: Implications for Teacher Educators.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>DeRoche, Edward</p> <p>1997-01-01</p> <p>Provides a brief historical background for the <span class="hlt">current</span> character education movement. Identifies mandates and support for character education in <span class="hlt">California</span>'s schools and shares implications of the character education movement for <span class="hlt">California</span> teachers. Includes a list of <span class="hlt">California</span>'s Standards for the Teaching Profession regarding character</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=finance&pg=2&id=ED515619','ERIC'); return false;" href="http://eric.ed.gov/?q=finance&pg=2&id=ED515619"><span id="translatedtitle">Pathways for School Finance in <span class="hlt">California</span>. Technical Appendix</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rose, Heather; Sonstelie, Jon; Weston, Margaret</p> <p>2010-01-01</p> <p>This is a technical appendix for the report, "Pathways for School Finance in <span class="hlt">California</span>" (ED515651). "Pathways for School Finance in <span class="hlt">California</span>" simulates alternatives to <span class="hlt">California</span>'s <span class="hlt">current</span> school finance system. This appendix provides more information about the revenues used in those simulations. The first section describes the districts and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26437633','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26437633"><span id="translatedtitle">Biodiversity and Resilience of <span class="hlt">Ecosystem</span> Functions.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Oliver, Tom H; Heard, Matthew S; Isaac, Nick J B; Roy, David B; Procter, Deborah; Eigenbrod, Felix; Freckleton, Rob; Hector, Andy; Orme, C David L; Petchey, Owen L; Proena, Vnia; Raffaelli, David; Suttle, K Blake; Mace, Georgina M; Martn-Lpez, Berta; Woodcock, Ben A; Bullock, James M</p> <p>2015-11-01</p> <p>Accelerating rates of environmental change and the continued loss of global biodiversity threaten functions and services delivered by <span class="hlt">ecosystems</span>. Much <span class="hlt">ecosystem</span> monitoring and management is focused on the provision of <span class="hlt">ecosystem</span> functions and services under <span class="hlt">current</span> environmental conditions, yet this could lead to inappropriate management guidance and undervaluation of the importance of biodiversity. The maintenance of <span class="hlt">ecosystem</span> functions and services under substantial predicted future environmental change (i.e., their 'resilience') is crucial. Here we identify a range of mechanisms underpinning the resilience of <span class="hlt">ecosystem</span> functions across three ecological scales. Although potentially less important in the short term, biodiversity, encompassing variation from within species to across landscapes, may be crucial for the longer-term resilience of <span class="hlt">ecosystem</span> functions and the services that they underpin. PMID:26437633</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988EnMan..12..445S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988EnMan..12..445S"><span id="translatedtitle"><span class="hlt">Ecosystem</span> health: I. Measuring <span class="hlt">ecosystem</span> health</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schaeffer, David J.; Herricks, Edwin E.; Kerster, Harold W.</p> <p>1988-07-01</p> <p><span class="hlt">Ecosystem</span> analysis has been advanced by an improved understanding of how <span class="hlt">ecosystems</span> are structured and how they function. Ecology has advanced from an emphasis on natural history to consideration of energetics, the relationships and connections between species, hierarchies, and systems theory. Still, we consider <span class="hlt">ecosystems</span> as entities with a distinctive character and individual characteristics. <span class="hlt">Ecosystem</span> maintenance and preservation form the objective of impact analysis, hazard evaluation, and other management or regulation activities. In this article we explore an approach to <span class="hlt">ecosystem</span> analysis which identifies and quantifies factors which define the condition or state of an <span class="hlt">ecosystem</span> in terms of health criteria. We relate <span class="hlt">ecosystem</span> health to human/nonhuman animal health and explore the difficulties of defining <span class="hlt">ecosystem</span> health and suggest criteria which provide a functional definition of state and condition. We suggest that, as has been found in human/nonhuman animal health studies, disease states can be recognized before disease is of clinical magnitude. Example disease states for <span class="hlt">ecosystems</span> are functionally defined and discussed, together with test systems for their early detection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.B41E0251G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.B41E0251G"><span id="translatedtitle">Modeling soil moisture memory in savanna <span class="hlt">ecosystems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gou, S.; Miller, G. R.</p> <p>2011-12-01</p> <p>Antecedent soil conditions create an <span class="hlt">ecosystem</span>'s "memory" of past rainfall events. Such soil moisture memory effects may be observed over a range of timescales, from daily to yearly, and lead to feedbacks between hydrological and <span class="hlt">ecosystem</span> processes. In this study, we modeled the soil moisture memory effect on savanna <span class="hlt">ecosystems</span> in <span class="hlt">California</span>, Arizona, and Africa, using a system dynamics model created to simulate the ecohydrological processes at the plot-scale. The model was carefully calibrated using soil moisture and evapotranspiration data collected at three study sites. The model was then used to simulate scenarios with various initial soil moisture conditions and antecedent precipitation regimes, in order to study the soil moisture memory effects on the evapotranspiration of understory and overstory species. Based on the model results, soil texture and antecedent precipitation regime impact the redistribution of water within soil layers, potentially causing deeper soil layers to influence the <span class="hlt">ecosystem</span> for a longer time. Of all the study areas modeled, soil moisture memory of <span class="hlt">California</span> savanna <span class="hlt">ecosystem</span> site is replenished and dries out most rapidly. Thus soil moisture memory could not maintain the high rate evapotranspiration for more than a few days without incoming rainfall event. On the contrary, soil moisture memory of Arizona savanna <span class="hlt">ecosystem</span> site lasts the longest time. The plants with different root depths respond to different memory effects; shallow-rooted species mainly respond to the soil moisture memory in the shallow soil. The growing season of grass is largely depended on the soil moisture memory of the top 25cm soil layer. Grass transpiration is sensitive to the antecedent precipitation events within daily to weekly timescale. Deep-rooted plants have different responses since these species can access to the deeper soil moisture memory with longer time duration Soil moisture memory does not have obvious impacts on the phenology of woody plants, as these can maintain transpiration for a longer time even through the top soil layer dries out.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMNH33A1640R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMNH33A1640R"><span id="translatedtitle"><span class="hlt">California</span> Tsunami Policy Working Group</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Real, C. R.; Johnson, L. A.</p> <p>2012-12-01</p> <p><span class="hlt">California</span> has established a Tsunami Policy Working Group of specialists from government and industry, from diverse fields including tsunami, seismic, and flood hazards, local and regional planning, structural engineering, natural hazard policy, and coastal engineering that have come together to facilitate the development of policy recommendations for tsunami hazard mitigation. The group is acting on findings from two major efforts: the USGS SAFRR (Science Application for Risk Reduction) Project - Tsunami Scenario, a comprehensive impact analysis of a large credible tsunami originating from a M 9.0 earthquake on the Aleutian Islands striking <span class="hlt">California</span>'s Coastline, and the State's Tsunami Hazard Mitigation and Education Program carried out by the <span class="hlt">California</span> Emergency Management Agency and the <span class="hlt">California</span> Geological Survey. The latter program is <span class="hlt">currently</span> involved with several projects to help coastal communities reduce their tsunami risk, including two pilot projects (Crescent City in Del Norte County and the City of Huntington Beach in Orange County) where tsunami risk is among the highest in <span class="hlt">California</span>, and a third pilot study focusing on the maritime community. The pilot projects are developing and testing probabilistic tsunami hazard products that will assist land-use and construction decisions for coastal development. The role of the policy group is to identify gaps and issues in <span class="hlt">current</span> tsunami hazard mitigation, make recommendations that will help eliminate these impediments and to provide advice that will assist in the development and implementation of effective tsunami hazard products that will help coastal communities improve tsunami resiliency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008EnMan..41..820L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008EnMan..41..820L"><span id="translatedtitle">The Greater Yellowstone <span class="hlt">Ecosystem</span>: Challenges for Regional <span class="hlt">Ecosystem</span> Management</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lynch, Heather J.; Hodge, Stephanie; Albert, Christian; Dunham, Molly</p> <p>2008-06-01</p> <p>An adaptive management approach is necessary but not sufficient to address the long-term challenges of the Greater Yellowstone <span class="hlt">Ecosystem</span> (GYE). Adaptive management, in turn, has its own particular challenges, of which we focus on two: science input, and stakeholder engagement. In order to frame our discussion and subsequent recommendations, we place the <span class="hlt">current</span> management difficulties into their historical context, with special emphasis on the 1990 Vision document, which attempted a broad synthesis of management goals for the <span class="hlt">ecosystem</span>. After examining these two key challenges in the context of the GYE, we make several recommendations that would allow for more effective <span class="hlt">ecosystem</span> management in the long term. First, we recommend adoption of the GYE as a site for long-term science research and monitoring with an emphasis on integrative research, long-term federal funding, and public dissemination of data. Second, we conclude that a clearer prioritization of legislative mandates would allow for more flexible <span class="hlt">ecosystem</span> management in the GYE, a region where conflicting mandates have historically led to litigation antithetical to effective <span class="hlt">ecosystem</span> management. Finally, we recommend a renewed attempt at an updated Vision for the Future that engages stakeholders (including local landholders) substantively from the outset.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B51H0446L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B51H0446L"><span id="translatedtitle">A nitrogen mass balance for <span class="hlt">California</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liptzin, D.; Dahlgren, R. A.</p> <p>2010-12-01</p> <p>Human activities have greatly altered the global nitrogen cycle and these changes are apparent in water quality, air quality, <span class="hlt">ecosystem</span> and human health. However, the relative magnitude of the sources of new reactive nitrogen and the fate of this nitrogen is not well established. Further, the biogeochemical aspects of the nitrogen cycle are often studied in isolation from the economic and social implications of all the transformations of nitrogen. The <span class="hlt">California</span> Nitrogen Assessment is an interdisciplinary project whose aim is evaluating the <span class="hlt">current</span> state of nitrogen science, practice, and policy in the state of <span class="hlt">California</span>. Because of the close proximity of large population centers, highly productive and diverse agricultural lands and significant acreage of undeveloped land, <span class="hlt">California</span> is a particularly interesting place for this analysis. One component of this assessment is developing a mass balance of nitrogen as well as identifying gaps in knowledge and quantifying uncertainty. The main inputs of new reactive nitrogen to the state are 1) synthetic nitrogen fertilizer, 2) biological nitrogen fixation, and 3) atmospheric nitrogen deposition. Permanent losses of nitrogen include 1) gaseous losses (N2, N2O, NHx, NOy), 2) riverine discharge, 3) wastewater discharge to the ocean, and 4) net groundwater recharge. A final term is the balance of food, feed, and fiber to support the human and animal populations. The largest input of new reactive nitrogen to <span class="hlt">California</span> is nitrogen fertilizer, but both nitrogen fixation and atmospheric deposition contribute significantly. Non-fertilizer uses, such as the production of nylon and polyurethane, constitutes about 5% of the synthetic N synthesized production. The total nitrogen fixation in <span class="hlt">California</span> is roughly equivalent on the 400,000 ha of alfalfa and the approximately 40 million ha of natural lands. In addition, even with highly productive agricultural lands, the large population of livestock, in particular dairy cows, requires a net influx of N in feed to the state. In terms of exports, the riverine N loads are smaller than many more mesic climates. Because many of the large population centers are on the coast, N discharged directly from wastewater treatment plants into the ocean is almost four times greater than the N discharge of all of the watersheds in the state combined. Gas losses are estimated through a combination of bottom up approaches using field data, emissions inventories, and numerical models. The largest uncertainties are in emissions of N2 and NH3. Calculated by difference, groundwater N loading represents the largest loss term in the mass balance. Contamination of groundwater with nitrates is a serious concern in many areas of the state. Given the long residence time of groundwater in many aquifers like the Central Valley the <span class="hlt">current</span> and past N inputs to groundwater pose a hazard to drinking water supplies for decades to come. These calculations along with the analysis of management and policy tools will help elucidate the spatial location or activities that would be best to target to reduce the negative consequences of human alteration of the nitrogen cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=142418&keyword=conservation+AND+status+AND+small+OR+less+AND+well+AND+known+AND+groups+AND+New+AND+Zealand+AND+terrestrial+AND+invertebrates&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=58637976&CFTOKEN=35257766','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=142418&keyword=conservation+AND+status+AND+small+OR+less+AND+well+AND+known+AND+groups+AND+New+AND+Zealand+AND+terrestrial+AND+invertebrates&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=58637976&CFTOKEN=35257766"><span id="translatedtitle"><span class="hlt">CALIFORNIA</span> RCRA TSD FACILITY BOUNDARIES</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Polygon coverage of RCRA TSD facility boundaries in <span class="hlt">California</span>. These are derived from original maps and descriptions located in the US EPA Region 9 Records Center files. <span class="hlt">Current</span> TSD facility designations were extracted from the ARIS (RCRIS) database in June 1998. Auxiliary tabl...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED450293.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED450293.pdf"><span id="translatedtitle">The <span class="hlt">California</span> School Psychologist, 2000.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Jimerson, Shane R., Ed.; Wilson, Marilyn, Ed.</p> <p>2000-01-01</p> <p>This publication of the <span class="hlt">California</span> Association of School Psychologists reflects a broad array of topics for those who serve a diverse group of students with a range of needs. The articles in this volume address several <span class="hlt">current</span> topics, including cognitive assessment with bilingual students; cultural considerations when working with parents;</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED469197.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED469197.pdf"><span id="translatedtitle">The <span class="hlt">California</span> School Psychologist, 2002.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Jimerson, Shane R., Ed.</p> <p>2002-01-01</p> <p>This volume of the journal for the <span class="hlt">California</span> Association of School Psychologists provides <span class="hlt">current</span> information on a broad array of topics related to the work of school psychologists. Articles in this volume provide information addressing an assortment of important issues in the field, including: the translations and validation of an assessment for…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li>