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Sample records for st lawrence estuary

  1. Morphodynamics in sediment-starved inner-shelf submarine canyons (Lower St. Lawrence Estuary, Eastern Canada)

    E-print Network

    Morphodynamics in sediment-starved inner-shelf submarine canyons (Lower St. Lawrence Estuary Available online 3 September 2014 Keywords: Submarine canyons Inner-shelf Internal waves Slope failures in a series of inner-shelf submarine canyons located in the Lower St. Lawrence Estuary were examined using

  2. Submarine canyons and channels in the Lower St. Lawrence Estuary (Eastern Canada): Morphology, classification and recent sediment dynamics

    E-print Network

    Submarine canyons and channels in the Lower St. Lawrence Estuary (Eastern Canada): Morphology online 8 April 2015 Keywords: Submarine canyons Gravity flows St. Lawrence Estuary Seabed morphology Sedimentary processes Series of submarine canyons and channels observed in the Lower St. Lawrence Estuary

  3. Turbulent nitrate fluxes in the Lower St. Lawrence Estuary, Canada

    NASA Astrophysics Data System (ADS)

    Cyr, Frédéric; Bourgault, Daniel; Galbraith, Peter S.; Gosselin, Michel

    2015-03-01

    Turbulent vertical nitrate fluxes were calculated using new turbulent microstructure observations in the Lower St. Lawrence Estuary (LSLE), Canada. Two stations were compared: the head of the Laurentian Channel (HLC), where intense mixing occurs on the shallow sill that marks the upstream limit of the LSLE, and another station located about 100 km downstream (St. 23), more representative of the LSLE mean mixing conditions. Mean turbulent diffusivities and nitrate fluxes at the base of the surface layer for both stations were, respectively (with 95% confidence intervals): K¯HLC = 8.6>(3.2,19>) × 10-3 m2 s-1,K¯23 = 4.4>(2.3,7.6>) × 10-5 m2 s-1,F¯HLC = 95>(18,300>) mmol m-2 d-1, and F¯23 = 0.21>(0.12,0.33>) mmol m-2 d-1. Observations suggest that the interplay between large isopleth heaving near the sill and strong turbulence is the key mechanism to sustain such high turbulent nitrate fluxes at the HLC (two to three orders of magnitude higher than those at Station 23). Calculations also suggest that nitrate fluxes at the HLC alone can sustain primary production rates of 3.4>(0.6,11>) g C m-2 mo-1 over the whole LSLE, approximately enough to account for a large part of the phytoplankton bloom and for most of the postbloom production. Surfacing nitrates are also believed to be consumed within the LSLE, not leaving much to be exported to the rest of the Gulf of St. Lawrence. This article was corrected on 13 APR 2015. See the end of the full text for details.

  4. Cancer in beluga from the St. Lawrence estuary.

    PubMed Central

    Hammill, Mike O; Lesage, Véronique; Kingsley, Michael C S

    2003-01-01

    Martineau et al. (2002) reported that St. Lawrence beluga (SLB) have high cancer rates. Unfortunately, errors in their interpretation of the data have led them to overstate the importance of cancer and its links to environmental sources. PMID:12573920

  5. Late-Quaternary morpho-sedimentology and submarine mass movements of the Betsiamites area, Lower St. Lawrence Estuary, Quebec, Canada

    E-print Network

    St-Ong, Guillaume

    Late-Quaternary morpho-sedimentology and submarine mass movements of the Betsiamites area, Lower St 2008 Accepted 4 March 2008 Keywords: submarine mass movements morpho-sedimentology multibeam bathymetry seismic reflection earthquakes St. Lawrence Estuary Betsiamites River A complex submarine geomorphology

  6. Immunotoxicity in plaice exposed to marine sediments in Baie des Anglais on the St. Lawrence Estuary

    SciTech Connect

    Lacroix, A.; Nagler, J.; Lee, K.; Lebeuf, M.; Cyr, D.; Fournier, M.

    1995-12-31

    The sediments of Baie des Anglais on the St. Lawrence Estuary have a history of environmental contamination. The purpose of the present study was to determine whether or not the immune system of American Plaice (Hippoglossoides Platessoides) could be affected following in-situ exposure at three different sites in and near Baie des Anglais. These sites vary with their proximity to local industry, Sites 1 and 2 (within the bay) being the closest and Site 3 (outside the bay) the furthest away. Fishes placed in cages at each site for three weeks, displayed head kidney cell immune responses (i.e., phagocytosis) modifications indicating that Site 1 was most immunotoxic and site 3 the least. Sediment chemical analysis show a gradient in contaminant concentrations with the highest levels recorded at Site 1, about 10-fold less at Site 2 and 100-fold less at Site 3. Organics predominated (PAHs, PCBs, PCDFs) with heavy metal concentrations low and representative of background levels for the St. Lawrence Estuary. The results obtained indicate that contaminants present in the sediments are bioavailable to fish and significantly affect their immune system.

  7. Trophic interactions in the St. Lawrence Estuary (Canada): Must the blue whale compete for krill?

    NASA Astrophysics Data System (ADS)

    Savenkoff, C.; Comtois, S.; Chabot, D.

    2013-09-01

    Inverse methodology was used to construct a mass-balance model of the Lower St. Lawrence Estuary (LSLE) for the 2008-2010 time period. Our first objective was to make an overall description of community structure, trophic interactions, and the effects of fishing and predation on the vertebrate and invertebrate communities of the ecosystem. A second objective was to identify other important predators of krill, and to assess if these compete with blue whales, listed as endangered under the Canadian Species at Risk Act in 2005 (northwest Atlantic population). The Estuary and the Gulf of St. Lawrence are summer feeding grounds for blue whales and other marine mammals. Blue whales eat only euphausiids (krill) and require dense concentrations of prey to meet their energy requirements, which makes them particularly vulnerable to changes in prey availability. In the LSLE, many species from secondary producers (hyperiid amphipods, other macrozooplankton) to top predators (fish, birds, and marine mammals) consumed euphausiids. Consequently, krill predators were found at all consumer trophic levels. However, our results showed that only about 35% of the estimated euphausiid production was consumed by all predator species combined. Euphausiid did not seem to be a restricted resource in the LSLE ecosystem, at least during the study period. The blue whale did not appear to have to compete for krill in the LSLE.

  8. Hypoxia in the bottom water of the St. Lawrence Estuary: Is this ecosystem on borrowed time?

    NASA Astrophysics Data System (ADS)

    Lefort, S.; Gratton, Y.; Mucci, A.; Dadou, I.; Gilbert, D.

    2012-04-01

    When the rate of oxygen consumption in water exceeds the rate of supply, the oxygen concentration decreases and may reach levels that threaten the survival of many aquatic organisms. Waters with such low oxygen levels are termed severely hypoxic ([O2] < 62.5 µmol L-1). In 2011, the World Resources Institute identified 479 hypoxic coastal zones around the world, including fjords, estuaries, bays, shelves, as well as enclosed and semi-enclosed seas. These hypoxic environments are mainly found in coastal areas as a result of industrial and agricultural fertilizer discharge (i.e. eutrophication), and they develop during summer when the water column is strongly stratified; but hypoxia may also occur naturally and persist year-round. Historical records reveal that the dissolved oxygen concentration has progressively decreased in the bottom water of the Lower St. Lawrence Estuary (LSLE) during the last century and reached the severe hypoxic threshold in the 1980s where it has hovered ever since. The development of severe hypoxia in the LSLE has been mostly attributed to a gradual change in the properties (e.g. higher temperature, lower dissolved oxygen concentration) of the bottom water that enters the Laurentian Channel (Gulf of St. Lawrence, Eastern Canada). In addition, evidence of eutrophication has been reported in the LSLE, possibly increasing the oxygen demand in the water column and sediment. Increased respiration rates in the bottom water, in response to warming (from 3.3 to 5°C), has also been proposed to explain the increased depletion of oxygen in the Gulf. Nevertheless, whether hypoxia in the bottom water of the Laurentian Channel results from anthropogenic or natural forcings or both remain unclear. This presentation will examine the processes that govern the spatial distribution of dissolved oxygen in the water column and identify the causes that led to the development of large-scale hypoxia in the bottom waters of the LSLE. A laterally integrated advection-diffusion two-dimensional model was implemented to simulate the spatial distribution of dissolved oxygen and the development of hypoxic conditions in the deep waters of the Laurentian Channel (Estuary and Gulf of St. Lawrence). Our simulations reveal that the horizontal distribution of dissolved oxygen in the bottom waters of the Laurentian Channel is determined by a combination of physical and biogeochemical processes, whereas its vertical distribution is governed by the deep water circulation. This result strongly suggests that the physics of the system and the source water properties are mostly responsible for the oxygen depletion and its distribution pattern in the deep water column.

  9. Hypoxia in the St. Lawrence Estuary: How a Coding Error Led to the Belief that “Physics Controls Spatial Patterns”

    PubMed Central

    2015-01-01

    Two fundamental sign errors were found in a computer code used for studying the oxygen minimum zone (OMZ) and hypoxia in the Estuary and Gulf of St. Lawrence. These errors invalidate the conclusions drawn from the model, and call into question a proposed mechanism for generating OMZ that challenges classical understanding. The study in question is being cited frequently, leading the discipline in the wrong direction. PMID:26397371

  10. Oceanography and Quaternary geology of the St. Lawrence Estuary and the Saguenay Fjord This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-print Network

    St-Ong, Guillaume

    Oceanography and Quaternary geology of the St. Lawrence Estuary and the Saguenay Fjord This article of the St. Lawrence Estuary and the Saguenay Fjord Anne de Vernal1 , Guillaume St-Onge2 and Denis Gilbert3 1, the Laurentian Channel (Figure 1) and the Saguenay Fjord are valleys resulting from glacial erosion [6

  11. Electrolyte changes of serum and muscle, and related mortalities in maturing Anguilla rostrata migrating down the St. Lawrence Estuary (Canada)

    NASA Astrophysics Data System (ADS)

    Dutil, J.-D.

    1984-03-01

    This study was made to investigate changes in serum and muscle ion concentrations and related mortalities in maturing Anguilla rostrata migrating down the St. Lawrence Estuary. Mortalities take place in the freshwater portion of the St. Lawrence. Electrolyte concentrations of moribund eels taken in freshwater were compared to those of freshwater and salt water controls. Moribund eels had a much lower serum osmolality (270 mOsm/kg) than the controls (328 and 358 mOsm/kg). This resulted from low sodium (125 mEq/l) and particularly low chloride (69 mEq/l) contents in the moribund eels compared to the freshwater controls (153 and 117 mEq/l) and the salt water controls (179 and 137 mEq/l). There was also a general decrease in muscle ion concentrations in moribund eels though the percentage water was similar to that of the freshwater controls (64.0 and 63.7%). The changes measured between the freshwater controls and the salt water controls in nature are similar to those measured on Anguilla anguilla in laboratory. These results suggest that mortalities are related to failure by some of the maturing eels to maintain their mineral balance in freshwater. Hypothesis is made that maturing eels migrating long distances in freshwater or retarded by physical or chemical barriers, start to excrete sodium and chloride under hormonal control before they have reached brackish water. In the conditions that prevail in the St. Lawrence Estuary, this results in mineral unbalance and possibly in mortalities.

  12. Cancer in wildlife, a case study: beluga from the St. Lawrence estuary, Québec, Canada.

    PubMed Central

    Martineau, Daniel; Lemberger, Karin; Dallaire, André; Labelle, Philippe; Lipscomb, Thomas P; Michel, Pascal; Mikaelian, Igor

    2002-01-01

    A population of approximately 650 beluga (Delphinapterus leucas) inhabits a short segment of the St. Lawrence estuary (SLE). Over 17 years (1983-1999), we have examined 129 (or 49%) of 263 SLE beluga carcasses reported stranded. The major primary causes of death were respiratory and gastrointestinal infections with metazoan parasites (22%), cancer (18%), and bacterial, viral, and protozoan infections (17%). We observed cancer in 27% of examined adult animals found dead, a percentage similar to that found in humans. The estimated annual rate (AR) of all cancer types (163/100,000 animals) is much higher than that reported for any other population of cetacean and is similar to that of humans and to that of hospitalized cats and cattle. The AR of cancer of the proximal intestine, a minimum figure of 63 per 100,000 animals, is much higher than that observed in domestic animals and humans, except in sheep in certain parts of the world, where environmental contaminants are believed to be involved in the etiology of this condition. SLE beluga and their environment are contaminated by polycyclic aromatic hydrocarbons (PAHs) produced by the local aluminum smelters. The human population living in proximity of the SLE beluga habitat is affected by rates of cancer higher than those found in people in the rest of Québec and Canada, and some of these cancers have been epidemiologically related to PAHs. Considered with the above observations, the exposure of SLE beluga to PAHs and their contamination by these compounds are consistent with the hypothesis that PAHs are involved in the etiology of cancer in these animals. PMID:11882480

  13. Polychlorinated dibenzo-p-dioxins and dibenzofurans in sediments and biota of the Saguenay Fjord and the St. Lawrence Estuary

    SciTech Connect

    Brochu, C.; Moore, S.; Pelletier, E.

    1995-12-31

    Sediment samples and marine organisms were collected in the Saguenay Fjord and at two selected sites of the St. Lawrence Estuary in 1991. Total PCDDs and total PCDFs ranged from 22 to 352 ng kg{sup {minus}1} and 29 to 188 ng kg{sup {minus}1}, respectively in Saguenay sediments, while total PCDFs reached, 287 ng kg{sup {minus}1} in Baie des Anglais, a small and deep bay of the St. Lawrence Estuary impacted by PCBs during the 1970s. All biological samples contained detectable amounts of chlorinated dibenzodioxins and dibenzofurans, apart from the North Atlantic cod (Gadus morhua). The highest concentrations (up to 59.7 ng kg{sup {minus}1} total PCDFs and 2.54 ng kg{sup {minus}1} 2,3,7,8T4CDD Equivalent (TCDD TEQ)) were observed in crab (Chionoecetes opilio) caught in Saguenay Fjord and in crab and whelk (Buccinwn undatwn) collected in Baie des Anglais. Nordic shrimp (Pandalus borealis) is less contaminated with a maximum total PCDDs and PCDFs concentration of 14.0 ng kg{sup {minus}1} and TCDD TEQ never exceeding 0.7 ng kg{sup {minus}1}. Greenland halibut (Reinhardtius hippoglossoides) caught in the Saguenay Fjord contained only 2,3,7,8 substituted congeners in their tissues leading to a low average TCDD TEQ of 1.66 ng kg{sup {minus}1}. Based upon this first series of results, benthic organisms and fish from the Saguenay Fjord and the north shore of the St. Lawrence Estuary are exposed to low levels of PCDDs and PCDFs, and carry tissue concentrations well below international guidelines for fisheries products.

  14. Immune competence of rats fed with beluga whale blubber from the contaminated St. Lawrence estuary

    SciTech Connect

    Brousseau, P.; Lapierre, P.; Guise, S. De; Beland, P.; Martineau, D.; Fournier, M.

    1995-12-31

    Over the last decades, high concentrations of environmental contaminants such as PCBs have been measured in the tissues of many species of marine mammals from different parts of the world. Even though many deleterious effects of these compounds have been reported in laboratory animals, the overall risk associated with these contaminants in wild animals is still not clearly understood. However, necropsy of St. Lawrence belugas showed numerous severe and disseminated infections with rather mildly pathogenic bacteria. Moreover, 37% of all the tumors reported in cetaceans were observed in St. Lawrence beluga whales. Indeed, both observations suggest immunosuppression. The aim of the study was to determine if contaminants present in fat tissues of belugas might provoke deleterious effect to their immune system if, under some circumstances, they are released into the circulation. To assess their immunotoxic potential, rats were fed for two months on a diet in which the lipids originated from the blubber of either highly polluted St. Lawrence belugas or relatively uncontaminated arctic belugas. Then, multiple immune responses were monitored. Those include phagocytosis, plaque forming cells, oxidative burst, natural killer cells, immunophenotyping and mitogenic assay. The results obtained show that only the humoral response of rats was impaired by the treatment. By combining all this information, the authors propose possible mechanisms of action to explain potential long-term consequences of environmental pollution.

  15. Stable isotope evidence for glacial lake drainage through the St. Lawrence Estuary, eastern Canada, ~13.1-12.9 ka

    USGS Publications Warehouse

    Cronin, T. M.; Rayburn, J.A.; Guilbault, J.-P.; Thunell, R.; Franzi, D.A.

    2012-01-01

    Postglacial varved and rhythmically-laminated clays deposited during the transition from glacial Lake Vermont (LV) to the Champlain Sea (CS) record hydrological changes in the Champlain-St. Lawrence Valley (CSLV) at the onset of the Younger Dryas ?13.1–12.9 ka linked to glacial lake drainage events. Oxygen isotope (?18O) records of three species of benthic foraminifera (Cassidulina reniforme, Haynesina orbiculare, Islandiella helenae) from six sediment cores and the freshwater ostracode Candona from one core were studied. Results show six large isotope excursions (?0.5 to >2‰) in C. reniforme ?18O values, five excursions in H. orbiculare (<0.5 to ?1.8‰), and five smaller changes in I. helenae (<0.5‰). ?18O values in Candona show a 1.5–2‰ increase in the same interval. These isotopic excursions in co-occurring marine and freshwater species in varve-like sediments indicate complex hydrological changes in the earliest Champlain Sea, including brief (sub-annual) periods of complete freshening. One hypothesis to explain these results is that multiple abrupt freshwater influx events caused surface-to-bottom freshening of the Champlain Sea over days to weeks. The most likely source of freshwater would have been drainage of the Morehead Phase of glacial Lake Agassiz, perhaps in a series of floods, ultimately draining out the St. Lawrence Estuary.

  16. Habitat use and movements of postfledging American black ducks (Anas rubripes) in the St. Lawrence estuary, Quebec

    USGS Publications Warehouse

    Clugston, D.A.; Longcore, J.R.; McAuley, D.G.; Dupuis, P.

    1994-01-01

    We used radiotelemetry to determine habitat use and movements of 38 female juvenile American black ducks (Anas rubripes) on the north shore of the St. Lawrence estuary, Quebec, from 28 August to 15 November 1991. Ducks separated into three groups based on habitat use: inland, estuarine, and those using a mixture of habitats. Ducks using mixed habitats used the greatest variety of habitat types, flew the greatest distances and most often between night roosts and day foraging areas, and were unlikely to be shot. The mean distance flown between night-use and day-use areas for all ducks increased nearly 50% after the hunting season began (overall mean = 6104 m, range 1500 - 26384 m). Mean home range size was 27.6 t 6.5 (SE) km2. Ducks exhibited stronger fidelity to wetlands used at night than to those used during the day. Ducks that were shot spent a high percentage of their time on the estuary (90.1 t 7.4 %) and exhibited high fidelity to a day-use area before the hunting season (73 t 7.3 %).

  17. Land use and nitrogen loading in seven estuaries along the southern Gulf of St. Lawrence, Canada

    NASA Astrophysics Data System (ADS)

    McIver, Reba; Milewski, Inka; Lotze, Heike K.

    2015-11-01

    Nitrogen loading from coastal watersheds is a principal factor associated with the decline in eelgrass bed health and cover in estuaries worldwide. We apply the Nitrogen Loading Model (NLM) framework developed in Waquoit Bay, Massachusetts to 7 estuaries in eastern New Brunswick. Using watershed-specific information on human population, wastewater production, atmospheric deposition, and land use in each watershed we estimate annual input of Total Dissolved Nitrogen (TDN) from point and non-point sources. We also estimate flushing time of each estuary using available hydrodynamic and bathymetric data incorporated in a tidal prism model. Finally, we validate the NLM results by testing the link between estimated nitrogen loading, flushing time and nitrogen signals in eelgrass tissue including nitrogen content and stable isotopes. Overall, total nitrogen load (kg TDN yr-1) was strongly dependent on watershed and estuary size, while loading rate per unit watershed area (yield) was linked to watershed population density. Atmospheric deposition was the largest contributor of nitrogen to all estuaries except one, where seafood processing effluent was the greatest source. Stable isotope analysis of eelgrass tissue reflected this distinction, with high ?15N values of 8-10‰ related to high wastewater loading, compared to 2-6.5‰ in the other estuaries that receive proportionally more atmospheric deposition. Tissue nitrogen content was positively related to nitrogen yields and loading rate per volume of estuary, highlighting the influence of variable watershed:estuary size ratio. Multiple regression analysis identified a significant interaction between nitrogen yield and flushing time on eelgrass tissue nitrogen content and isotopes, pointing to the mitigating effect an estuary's quick flushing time can have on the expression of nitrogen enrichment in primary producers. The compilation of new information on nitrogen loading to east Canadian estuaries is a novel contribution from a region where human influences are still at a relatively low level, and hence will add to existing information from cold temperate, mainly forested watershed-estuary environments.

  18. Spatial distribution and viability of Alexandrium tamarense resting cysts in surface sediments from the St. Lawrence Estuary, Eastern Canada

    NASA Astrophysics Data System (ADS)

    Gracia, Stéphanie; Roy, Suzanne; Starr, Michel

    2013-04-01

    The dinoflagellate Alexandrium tamarense Group 1 (as defined by Lilly et al., 2007) is responsible for recurrent outbreaks of paralytic shellfish poisoning (PSP) in the St. Lawrence Estuary (SLE), Eastern Canada. In August 2008, a major bloom of A. tamarense developed in the SLE and caused major mortality of fish, seabirds and marine mammals notably in the vicinity of a marine park. Eleven months later, surface (0-5 cm) and deeper (5-10 cm) sediments were sampled to determine resting cysts concentrations, locate prospective cyst seedbeds and examine if these had changed following this major bloom. This information is thought to be important to understand inter-annual patterns in algal toxicity, cyst abundance being a good predictor of subsequent bloom magnitude in some regions. Surface cyst distribution was heterogeneous and it confirmed the location of the cyst seedbed previously reported on the north shore near the Manicouagan/aux-Outardes Rivers (>500 cysts cm-3). A zone of cyst accumulation was also observed on the south shore of the SLE (maximum of 1200 cysts cm-3), with higher concentrations relative to previous cyst mapping in the 1980s. A mismatch was observed between the zones with high surface cyst concentrations and those where the highest PSP toxins were detected (used as a proxy for vegetative cells in the water column). Cyst concentrations were negatively correlated with PSP levels from the same sites, suggesting that cysts were formed and deposited away from the major sites of toxicity. Deposition likely took place near the end of the bloom, once it had reached the eastern boundary of the SLE. PSP toxicity was worse near the peak of the bloom, which occurred westward of this region. This highlights the dynamic behaviour of local blooms, influenced by the estuarine and mesoscale circulation. Interestingly, the major bloom of August 2008 was not followed by particularly large cyst deposition or by any major bloom in 2009 in this region. Cyst viability was also examined, using Sytox Green, and found to be highest (nearly 100%) in the sites where cyst concentrations were maximum. Our results call for further investigation of the cyst mapping hypothesis in the St. Lawrence, where the local circulation seems to have an overriding influence on cyst deposition patterns.

  19. A twenty-one year temporal trend of persistent organic pollutants in St. Lawrence Estuary beluga, Canada.

    PubMed

    Lebeuf, Michel; Measures, Lena; Noël, Michelle; Raach, Meriem; Trottier, Steve

    2014-07-01

    Persistent organic pollutants (POPs) were measured in blubber from 144 stranded adult belugas (Delphinapterus leucas) found on the shores of the St. Lawrence Estuary (SLE) between 1987 and 2007. Temporal trends of POP concentrations (ln transformed) in beluga were described by three models, zero slope (ZS), linear (L) and two-segment piecewise (PW). Often two but sometimes all three models were equivalent in describing temporal trends based on Akaike's Information Criterion for small sample sizes. Over this 21-year time period, concentrations of most legacy POPs, including PCBs, DDTs and HCHs, exhibited relatively weak (?11% per year) but significant decreasing trends in beluga. For PBDEs, temporal trends were best described by a PW model, characterizing a rapid increase until 1997-1998 followed by a slower increase for males and a steady-state for females. Potential cofactors such as blubber lipid content and carcass state of preservation did not show any significant temporal trends over the time period considered. Nitrogen stable isotope ratios (?(15)N) in beluga liver, a proxy of trophic level, could not be associated to any effect on temporal trends of POP concentrations in beluga. Several POPs exhibited significant relationships with age of beluga and data were age-adjusted. Temporal trends of POP concentrations adjusted for age of beluga were reassessed but results were essentially identical as those obtained with the original POP data. Overall, POP temporal trends observed in SLE beluga are consistent with changes expected from regulations and restrictions in the use of these compounds in developed countries. PMID:24742546

  20. Recent transfer of coastal sediments to the Laurentian Channel, Lower St. Lawrence Estuary (Eastern Canada),

    E-print Network

    St-Ong, Guillaume

    (Eastern Canada), through submarine canyon and fan systems Hubert Gagné & Patrick Lajeunesse & Guillaume St to study the activity of submarine canyons and fans near the city of Les Escou- mins, on the North Shore. Introduction Submarine canyons are initiated by failures on depositional oversteepenings of continental slopes

  1. Immune functions in the Fisher rat fed beluga whale (Delphinapterus leucas) blubber from the contaminated St. Lawrence estuary

    SciTech Connect

    Lapierre, P.; Guise, S. De; Muir, D.C.G.; Norstrom, R.; Beland, P.; Fournier, M.

    1999-02-01

    In order to assess the immunotoxic potential of food naturally contaminated with PCBs and other organohalogens, Fisher rats were fed a diet in which the lipids originated from the blubber of either a highly polluted St. Lawrence beluga or a relatively uncontaminated Arctic beluga. After a period of 2 months, different immune functions were evaluated, including lymphoblastic transformation, natural killer cell activity, plaque-forming cells, phagocytosis, oxidative burst, and immunophenotyping. For all assays, rats fed at St. Lawrence beluga blubber diet or a mixture of Arctic and St. Lawrence beluga blubber diet were not different from control rats fed a diet containing Arctic beluga blubber. These results are inconsistent with the well-known immunosuppressive effects of organochlorines in numerous species and with the lesions suggestive of organochlorine-related immunosuppression that are observed in St. Lawrence belugas. The lack of observable immunotoxic effects in rats fed contaminated beluga blubber might be explained by antagonistic effects in the organohalogen mixture, by a response specific to the rat, by a strain-related lack of sensitivity to organochlorines, or by insufficient dose due to the shortness of the exposure period or the route of exposure.

  2. Submarine canyons and channels in the Lower St. Lawrence Estuary (Eastern Canada): Morphology, classification and recent sediment dynamics

    NASA Astrophysics Data System (ADS)

    Normandeau, Alexandre; Lajeunesse, Patrick; St-Onge, Guillaume

    2015-07-01

    Series of submarine canyons and channels observed in the Lower St. Lawrence Estuary (LSLE) provide an opportunity to analyze in great detail the morphology, spatial distribution and modern activity of such systems in a relatively shallow (? 300 m) semi-enclosed basin. Based on their geomorphology and physical settings, the canyons and channels were classified into four categories according to their feeding sources (ancient or recent): glacially-fed, river-fed, longshore drift-fed and sediment-starved systems. Their activity was interpreted based on geomorphological characteristics such as the presence of bedforms related to gravity flows, backscatter intensity, axial incision and the presence of rapidly deposited layers in surficial sediments. River-fed deltas were interpreted as inactive, mainly because suspended sediment concentrations at river mouths are low, preventing the generation of hyperpycnal currents or delta-lip failures related to high sediment supply. Longshore drift-fed canyons, present where the coastal shelf narrows, were found to be episodically active probably due to earthquakes or extreme storm events. Unlike other longshore drift-fed canyons observed elsewhere in the world, they are active infrequently because of the modern low rates of sediment supply to their heads. The most active canyons are the sediment-starved type and were observed near Pointe-des-Monts. Their activity is probably due to slope failures and to the presence of strong hydrodynamic processes. Therefore, sediment supply is not the main mechanism responsible for modern canyon and channel activity in the LSLE. However, sediment supply has been an important factor during the formation of the submarine channels and canyons. Their quasi-exclusive occurrence on the Québec North Shore is attributed to its larger watershed and important sedimentary delivery during deglaciation. The Québec North Shore watershed is 20 times greater than the Québec South Shore watershed, which favored the transport of greater volumes of sediment during the early-Holocene. Moreover, the slope proximity to the shore led to the formation of longshore-drift fed systems on the North Shore when sediment supplied to rivers were transferred on a narrow shelf.

  3. Cyclic steps in proglacial delta fronts: New insights from Upper Pleistocene-Holocene successions, St. Lawrence Estuary and Gulf, Québec, Canada

    NASA Astrophysics Data System (ADS)

    Dietrich, Pierre; Ghienne, Jean-François; Normandeau, Alexandre; Lajeunesse, Patrick

    2015-04-01

    Proglacial delta fronts in both present-day systems and in the sedimentary record frequently include sand-sized, upstream-migrating bedforms. Although several studies have recently monitored their sediment dynamics, their formative processes are still matter to debate. Here we report on two Pleistocene-Holocene proglacial deltaic successions located on the North Shore of the St. Lawrence Estuary and Gulf, Québec, Canada. Owing to a well-constrained pattern of glacio-isostatic rebound, these now-emerged successions are characterized by accurate palaeo-bathymetric reconstructions. In our case study, we describe backstepping (upstream-migrating) cross strata lying on delta foresets at shallow bathymetries ranging from 10 m to deeper part, reaching in places 50 m. Cross strata, interpreted as being deposited by Froude-supercritical cyclic steps, are characterized by steep mean dips (up to 13°) and short-wavelength (10-20 m) undulations. They form backstepping assemblages of massive to faintly laminated sand bounded on either side by downslope-dipping erosive surfaces on which strata onlap and are truncated upslope and downslope respectively. Graded sand beds, sheared flamed mud layers, matrix- to clasts-supported pebbles or sand intraclasts occasionally occur. In a first case study located in the St. Lawrence Estuary (Portneuf), cyclic steps are borne by gently-sloped (2-3°) foresets deposits at depositional depth less than 50 m. Related sand includes graded beds, thin (5-10 mm) muddy interbeds and terrestrial organic debris. In a second delta located in the Gulf of St. Lawrence (Moisie River), backstepping, faintly laminated gravelly sand beds are directly overlain by pebbly topsets constituted by the subaqueous termination of a sandur. They are in addition either sharply truncated or are passing gradually downslope to regular, steep-sloped gilbert-like delta foresets. Scour infills with backsets are commonly associated with these strata that were deposited at very shallow bathymetries (10 m) as inferred from the stratigraphic architecture. These features suggest that river outflow directly derived from proglacial distributary channel(s) on the delta plain is responsible for the genesis of cyclic steps on delta foresets. The outflow maintained its inherited supercritical state without experiencing a hydraulic jump while entering the sea. This scenario is an alternative to depositional models linking cyclic steps generation and mass-wasting processes related to mouth bars oversteepening. We argue that either meltwater outburst flows issuing from a nearby ice-margin or spring low tide condition, or a combination of both, can produce adequate flow conditions, in terms of water and sediment discharge, for creating supercritical flow and related depositional structures in delta front settings.

  4. Investigation into the response of the auditory and acoustic communications systems in the Beluga whale (Delphinapterus leucas) of the St. Lawrence River Estuary to noise, using vocal classification

    NASA Astrophysics Data System (ADS)

    Scheifele, Peter Martin

    2003-06-01

    Noise pollution has only recently become recognized as a potential danger to marine mammals in general, and to the Beluga Whale (Delphinapterus leucas) in particular. These small gregarious Odontocetes make extensive use of sound for social communication and pod cohesion. The St. Lawrence River Estuary is habitat to a small, critically endangered population of about 700 Beluga whales who congregate in four different sites in its upper estuary. The population is believed to be threatened by the stress of high-intensity, low frequency noise. One way to determine whether noise is having an effect on an animal's auditory ability might be to observe a natural and repeatable response of the auditory and vocal systems to varying noise levels. This can be accomplished by observing changes in animal vocalizations in response to auditory feedback. A response such as this observed in humans and some animals is known as the Lombard Vocal Response, which represents a reaction of the auditory system directly manifested by changes in vocalization level. In this research this population of Beluga Whales was tested to determine whether a vocalization-as-a-function-of-noise phenomenon existed by using Hidden Markhov "classified" vocalizations as targets for acoustical analyses. Correlation and regression analyses indicated that the phenomenon does exist and results of a human subjects experiment along with results from other animal species known to exhibit the response strongly implicate the Lombard Vocal Response in the Beluga.

  5. Mid and late Holocene dust deposition in eastern Canada - a preliminary multi-proxy record from the Baie bog (St. Lawrence Estuary, Quebec)

    NASA Astrophysics Data System (ADS)

    Pratte, Steve; Garneau, Michelle; De Vleeschouwer, François

    2014-05-01

    Atmospheric mineral dust plays an important role in the Earth's climate through parameters such as atmospheric radiation, cloud properties and biogeochemical cycles. However, the high spatial and temporal variability of mineral dust and a lack of terrestrial archives in certain regions limit our understanding global dust-climate interactions. Ombrotrophic peatlands (bogs; atmospherically-fed only) are increasingly recognized as archives of atmospheric dust deposition. Their global distribution and high accumulation rates (i.e. high resolution) over the Holocene make them suitable substitute to marine and/or ice records. The Baie bog, located along the St. Lawrence Estuary (North Shore region, Quebec, Canada), was sampled to investigate dust deposition/palaeowinds in north eastern North America over the mid and late Holocene. The core was subsampled for elemental and isotopic geochemistry as well as particle size analyses, 210Pb and radiocarbon dating. Radiocarbon dating of the base of the peat sequence yielded an age of about 4300 yr cal BP. Initial results show periods of increased dust flux, calculated from REE concentrations, between 1000-1500 yr cal BP and 100-500 yr cal BP in the peat profile from 0.5 to 4 g m-2 yr-1. Higher dust fluxes usually occur in combination with greater particle size suggesting either stronger winds or a change of source. Periods of increased dust fluxes in the profile also correspond with changes in the macrofossil assemblages. A first attempt at source tracing through preliminary radiogenic isotopes analyses (Pb, Nd; ongoing) will also be discussed.

  6. 14C and 13C Contents of Dissolved Organic Matter in the St. Lawrence Estuary and in a Hydroelectric Reservoir From the Boreal Forest (Quebec)

    NASA Astrophysics Data System (ADS)

    Lamontagne, J.; Hélie, J.; Hillaire-Marcel, C.

    2004-05-01

    In this study we examine the 14C and 13C contents of Dissolved Organic Matter (DOM) in the St. Lawrence River, at its outlet near Quebec City, and in a large hydroelectric reservoir, from the Canadian Boreal forest (Robert-Bourassa reservoir) as a mean to document the origin and residence time of DOM in such large catchments. Samples of DOM were collected bi-weekly at the Quebec City station from November 2001 until November 2002, as part of a geochemical monitoring program of the river, carried out since 1997. At the Robert-Bourassa reservoir, sampling operations took place from July 15 to July 26, 2001. All samples were filtered and acidified on site, and preserved in brown glass bottles at 4° C. Prior to their isotopic analysis, DOM samples were freeze-dried. 13C analyses were made at GEOTOP whereas 14C measurements were performed at the Lawrence Livermore National Laboratory, for samples coming from the St. Lawrence River, and at the Laboratoire d'Hydrologie et de géochimie isotopique of University Paris XI for samples originating from the Robert-Bourassa reservoir. Results are expressed respectively in ‰ vs. V-PDB and in % of modern carbon (% MC; i.e. 13.56 dpm/g C in 1950, for d13C=-25 ‰ ). D13C values averaging -26.3 ± 0.2 ‰ in the St. Lawrence, and -27.1 ± 0.2 ‰ at the Robert-Bourassa reservoir, indicate that DOC originates from terrestrial production, although a slight influence of aquatic DOC is seen in the St. Lawrence river during low water level episodes. In the river, DOC-14C activities range from 97.7 to 106.7 ± 0.5 %, with a mean value of 103.9 ± 0.5 %, whereas samples from Robert-Bourassa reservoir show a range of values between 108.5 and 110.5 ± 0.9 %, with a mean of 109.5 ± 0.9 %. In comparison, measurements made during the late 80's, in a small brook of Ontario, yielded 14C-DOM activities ranging from 113 to 118 % MC (Schiff et al., 1990). Meanwhile, 14C-activity of atmospheric CO2 has decreased of approximately the same proportion. We conclude that soil-derived DOC represents the production of immediately preceding years, notably in the Boreal Forest reservoir, but that contribution of longer residence time DOC from the Great Lakes likely accounts for the slightly lower 14C-DOC values found in the St. Lawrence River. In conclusion, 14C and 13C contents indicate an overall short DOM residence time, thus that the primary production at its origin, and its degradation and transport in the drainage network are fast processes. Reference: Schiff, S. L., R. Aravena, S. E. Trumbore et P. J. Dillon. 1990. Dissolved organic carbon cycling in forested watersheds : a carbon isotope approach. Water Resources Research, 26, no 12, 2949-2957.

  7. Holocene development of maritime ombrotrophic peatlands of the St. Lawrence North Shore in eastern Canada

    E-print Network

    : Ombrotrophic peatland Vegetation succession Macrofossil analyses Peat stratigraphy Holocene Fen­bog transition successions within ombrotrophic peatlands (bogs) from the northern shorelines of the St. Lawrence Estuary data show that treeless Sphagnum-dominated bogs have persisted over millennia and that fires had few

  8. Sivuqam Ungipaghaatangi (St. Lawrence Island Legends).

    ERIC Educational Resources Information Center

    Slwooko, Grace

    Transmitted orally for generations until the Eskimo language became a written one, the eleven St. Lawrence Island legends compiled in this volume for high school students tell of feats that were accomplished through supernatural power. Meant for both entertainment and instruction, the tales convey wise council indirectly through the conversations…

  9. St. Lawrence Island Eskimo Phonology and Orthography

    ERIC Educational Resources Information Center

    Krauss, Michael E.

    1975-01-01

    Central Siberian Yupik Eskimo is the language both of the natives of St. Lawrence Island and of the facing Siberian mainland, with few minor variations. A history of the language is given as it evolved in both countries, as well as a phonological analysis and orthographic developments on both sides. (SCC)

  10. Stratigraphic architecture and morphostructures of a recent glacio-isostatically forced-regressive delta: implications in terms of proglacial fluvial dynamics, North Shore of the St-Lawrence Estuary, Québec, Canada

    NASA Astrophysics Data System (ADS)

    Dietrich, Pierre; Ghienne, Jean-François; Schuster, Mathieu; Lajeunesse, Patrick; Deschamps, Rémy; Nutz, Alexis; Roquin, Claude; Duringer, Philippe

    2015-04-01

    Proglacial deltaic systems provide information about ice margins evolution, related glacio-isostatic rebound and proglacial fluvial dynamic during ice-sheet retreat. Here, we document a case study based on the North Shore of the St-Lawrence Estuary, Québec, Canada, recording the recession of the Laurentide Ice Sheet after the Last Glacial Maximum (Upper Wisconsinian-Holocene). The entire deltaic succession is exposed throughout coastal cliffs and river-cut terraces. Field investigations involve sedimentary logs, 14C dating and the characterization of morphosedimentary structures in the hinterlands. The delta initiates around 11 kyr Cal BP during an ice-front stabilization. Marine invasion on isostatically flexured lowlands led to the development of the Goldthwait Sea that reached a marine limit at the present-day 140 m elevation. At this time, ice contact and glaciomarine sediments were emplaced at the mouth of the major structural valleys. The subsequent glacial retreat farther inland turned the structural valleys into fjords into which deltas develop. The rapid fulfilling of these depocenters by glaciogenic sediments led to the emergence and coalescence of the deltas on the open sea. Lower delta front deposits are made up of mud while sand-sized, turbiditic deposits including facies related to supercritical flows (chutes, cyclic steps) prevail in the upper reaches. The delta plain is composed of gravelly facies deposited by braided streams. The progradation of the proglacial deltaic complex was about 10 km (thickness > 100 m) in only 1000 years in the open coast setting while the sea-level fall due to the glacio-isostatic rebound was up to 10 cm/yrs. This system remains active until the melting of the ice margins out of the catchment area at 10 kyr Cal BP. Sedimentary suites associated with the later paraglacial evolution comprise nearshore sand wedge (spit platform) and foreshore complexes. Throughout the entire proglacial deltaic development, no major fluvial incision occurred in spite of significant rates of sea-level fall (50m/1000 yrs). This owes to a fluvial equilibrium profile steeper than the descending regressive shoreline trajectory mainly due to an important glaciogenic sediment supply. Alternatively, fluvial entrenchment actively arose as soon as the ice margins retreated out of the catchment area in a context enduring lesser rates of sea-level fall. Fluvial entrenchment processes are explored, including buffer/buttress incision processes and the key role of bedrock thresholds, rate of sea level-fall and the drawdown of the glaciogenic/paraglacial sediment supply.

  11. Methylsulfone polychlorinated biphenyl and 2,2-bis(chlorophenyl)-1,1-dichloroethylene metabolites in beluga whale (Delphinapterus leucas) from the St. Lawrence River estuary and western Hudson Bay, Canada

    SciTech Connect

    Letcher, R.J.; Norstrom, R.J.; Muir, D.C.G.; Sandau, C.D.; Koczanski, K.; Michaud, R.; De Guise, S.; Beland, P.

    2000-05-01

    Knowledge is limited regarding methylsulfone (MeSO{sub 2})-polychlorinated biphenyl (PCB), and especially MeSo{sub 2}-2,2-bis(chlorophenyl)-1,1-dichloroethylene (DDE), metabolites in cetacean species. The authors hypothesized that the ability of beluga whale (Delphinapterus leucas) to biotransform PCB and DDE compounds, and to form and degrade their MeSO{sub 2}-PCB and -DDE metabolites, is related to the capacity for xenobiotic metabolism. Adipose biopsies were collected from male and female beluga whale from distinct populations in the St. Lawrence River estuary (STL) and western Hudson Bay (WHB), Canada, which are contrasted by the exposure to different levels of cytochrome P450 enzyme-inducing, chlorinated hydrocarbon contaminants. The PCBs, DDTs, DDEs, 28 MeSO{sub 2} metabolites of 14 meta-para chlorine-unsubstituted PCBs, and four MeSO{sub 2} metabolites of 4,4{prime}- and 2,4{prime}-DDE were determined. The mean concentrations of total ({Sigma}-) MeSO{sub 2}-PCB in male STL beluga (230 ng/g), and ratios of {Sigma}-MeSO{sub 2}-PCB to {Sigma}-PCB (0.05) and {Sigma}-precursor-PCB (0.17) were approximately twofold higher, whereas the {Sigma}-precursor-PCB to {Sigma}-PCB ratio was approximately twofold lower, than in male WHB beluga. Both populations had a low formation capacity for MeSO{sub 2}-PCBs with {le} six chlorines (<4% of {Sigma}-MeSO{sub 2}-PCBs). The congener patterns were dominated by trichloro- and tetrachloro-MeSO{sub 2}-PCBs, and tetrachloro- and pentachloro-MeSO{sub 2}-PCBs in WHB and STL animals, respectively. In addition to 2- and 3-MeSO{sub 2}-4,4{prime}-DDE, two unknown MeSO{sub 2}-2,4{prime}-DDEs were detected. The mean 3-MeSO{sub 2}-4,4{prime}-DDE concentration in STL beluga (1.2 ng/g) was much greater than in WHB animals. The concentrations of 4,4{prime}-DDE, and not 3-MeSO{sub 2}-4,4{prime}-DDE, increased with age in male STL animals. The authors demonstrated that sulfone formation and clearance is related to metabolic capacity, and thus PCB, DDE, and MeSO{sub 2}-PCB and -DDE toxicokinetics differ for STL and WHB beluga. In the past, the capacity of odontocetes for PCB and DDE biotransformation leading to persistent sulfone formation and clearance is related to metabolic capacity, and thus PCB, DDE, and MeSO{sub 2}-PCB and -DDE toxicokinetics differ for STL and WHB beluga. In the past, the capacity of odontocetes for PCB and DDE biotransformation leading to persistent sulfone metabolites has been underestimated. More information is needed for other cetacean species and marine mammals. The results of this study indicate that MeSO{sub 2}-PCBs and -DDEs need to be included in the toxicologic risk assessment of PCB and DDT exposure in odontocetes, and perhaps for cetaceans in general.

  12. Evaluating long-term regional climate variability in the maritime region of the St. Lawrence North Shore

    E-print Network

    (bogs) along the north shore of the Estuary and the Gulf of St. Lawrence in eastern Canada. Past water at the regional scale suggests a common climatic influence on bog paleohydrology but there are inconsistencies). The surface drying and increased hydrological variability after 3000 cal a BP in the studied bogs coincide

  13. Credit: Michael Anderson. NOAA Selects St. Louis River Estuary as

    E-print Network

    Credit: Michael Anderson. NOAA Selects St. Louis River Estuary as Habitat Focus Area The St. Louis scale. A Watershed in Need The St. Louis River runs along the border of Minnesota and Wisconsin will be an important addition to the restoration effort. The objectives we have identified in the St. Louis River

  14. Indication of a Lombard vocal response in the St. Lawrence River beluga

    NASA Astrophysics Data System (ADS)

    Scheifele, P. M.; Andrew, S.; Cooper, R. A.; Darre, M.; Musiek, F. E.; Max, L.

    2005-03-01

    Noise pollution is recognized as a potential danger to marine mammals in general, and to the St. Lawrence beluga in particular. One method of determining the impacts of noise on an animal's communication is to observe a natural and repeatable response of the vocal system to variations in noise level. This is accomplished by observing intensity changes in animal vocalizations in response to environmental noise. One such response observed in humans, songbirds, and some primates is the Lombard vocal response. This response represents a vocal system reaction manifested by changes in vocalization level in direct response to changes in the noise field. In this research, a population of belugas in the St. Lawrence River Estuary was tested to determine whether a Lombard response existed by using hidden Markhov-classified vocalizations as targets for acoustical analyses. Correlation and regression analyses of signals and noise indicated that the phenomenon does exist. Further, results of human subjects experiments [Egan, J. J. (1966), Ph.D. dissertation; Scheifele, P. M. (2003), Ph.D. dissertation], along with previously reported data from other animal species, are similar to those exhibited by the belugas. Overall, findings suggest that typical noise levels in the St. Lawrence River Estuary have a detectable effect on the communication of the beluga. .

  15. NAME: St. Lucie River Oyster Reef Habitat Restoration Project LOCATION: St. Lucie Estuary, Martin County, Florida

    E-print Network

    US Army Corps of Engineers

    NAME: St. Lucie River Oyster Reef Habitat Restoration Project LOCATION: St. Lucie Estuary, Martin of the restored habitat to document short- and long-term project success. EXPECTED BENEFITS: The proposed restoration of 2 acres of oyster reef in the St. Lucie Estuary will provide habitat for approximately 3

  16. Adapting to Climate Change and Variability in the Great Lakes-St. Lawrence Basin Great Lakes-St. Lawrence Basin Project

    E-print Network

    Adapting to Climate Change and Variability in the Great Lakes-St. Lawrence Basin 52 Great Lakes learned in the Great Lakes- St. Lawrence Basin (GLSLB) Project, we realized that it was in May 1992-St. Lawrence Basin Project: What Have We Learned? Linda Mortsch Environmental Adaptation Research Group

  17. Stocking young Atlantic salmon in St. Lawrence River system

    USGS Multimedia Gallery

    Thousands of young Atlantic salmon are released into the St. Regis River system (a tributary of the St. Lawrence River) in an effort to restore this diminished Lake Ontario fish population. The salmon were reared at the USGS Tunison Laboratory in Cortland, N.Y., and are released by USGS scienti...

  18. Evaluation of the contamination of marine algae (seaweed) from the St. Lawrence River and likely to be consumed by humans

    SciTech Connect

    Phaneuf, D.; Cote, I.; Dumas, P.; Ferron, L.A.; LeBlanc, A.

    1999-02-01

    The goal of the study was to assess the contamination of marine algae (seaweeds) growing in the St. Lawrence River estuary and Gulf of St. Lawrence and to evaluate the risks to human health from the consumption of these algae. Algae were collected by hand at low tide. A total of 10 sites on the north and south shores of the St. Lawrence as well as in Baie des Chaleurs were sampled. The most frequently collected species of algae were Fucus vesiculosus, Ascophyllum nodosum, Laminaria Longicruris, Palmaria palmata, Ulva lactuca, and Fucus distichus. Alga samples were analyzed for metals iodine, and organochlorines. A risk assessment was performed using risk factors. In general, concentrations in St. Lawrence algae were not very high. Consequently, health risks associated with these compounds in St. Lawrence algae were very low. Iodine concentration, on the other hand, could be of concern with regard to human health. Regular consumption of algae, especially of Laminaria sp., could result in levels of iodine sufficient to cause thyroid problems. For regular consumers, it would be preferable to choose species with low iodine concentrations, such as U. lactuca and P. palmata, in order to prevent potential problems. Furthermore, it would also be important to assess whether preparation for consumption or cooking affects the iodine content of algae. Algae consumption may also have beneficial health effects. Scientific literature has shown that it is a good source of fiber and vitamins, especially vitamin B{sub 12}.

  19. Influence of St. Lawrence River discharge on the circulation and hydrography in Canadian Atlantic waters

    NASA Astrophysics Data System (ADS)

    Ohashi, Kyoko; Sheng, Jinyu

    2013-04-01

    This study examines the effects of freshwater discharge from the St. Lawrence River (SLR) on the three-dimensional circulation and hydrography in Canada's Atlantic waters using a regional shelf circulation model based on the Princeton Ocean Model. The study region comprises the Gulf of St. Lawrence, the Scotian Shelf, and the Gulf of Maine. The model forcing includes atmospheric forcing at the sea surface; tidal elevation and currents at the lateral open boundaries; and freshwater discharge from the SLR and other major rivers in the region. The forcing at the lateral open boundaries also includes non-tidal currents as well as temperature and salinity fields produced by a coarse-resolution circulation model for the northwest Atlantic. The shelf circulation model is integrated for 5 years (1999-2003); the simulated hydrography and circulation during the last 4 years are compared to observations to assess the model's performance. Three additional model runs are made, called the climate, wet, and dry runs, in which the SLR discharge values specified in the model are respectively the long-term mean and the long-term mean plus or minus 3.5 standard deviations. Model results from the climate run demonstrate that the variability of freshwater flux in the St. Lawrence Estuary takes ˜100 days to reach Cabot Strait; ˜160 days to reach the central Scotian Shelf; and ˜220 days to reach the eastern Gulf of Maine. Within the Gulf of St. Lawrence, an increase in the SLR discharge results in a stronger Gaspé Current (up to ˜0.1 m s-1 stronger in the wet run than in the dry run) as well as lower salinity in the western part of the gulf. In the winter, the effect of a higher SLR discharge extends along the Scotian Shelf and into the Gulf of Maine, with salinity in both areas lower by ˜0.1 psu in the wet run than in the dry run.

  20. A Study of the St. Lawrence River Ecological Habitat

    ERIC Educational Resources Information Center

    Mesires, Maria

    2010-01-01

    Save the River, a grassroots advocacy group established in 1978, lobbies for policies to preserve the upper St. Lawrence River and uses the community's help to keep an eye on the existing habitats. Recently, they procured the Fresh Sound Foundation grant to support the development of new K-12 ecology curricula by local area teachers to educate…

  1. Spending Time and Money: Memories of Life in St. Lawrences

    ERIC Educational Resources Information Center

    Abraham, Jane; Cooper, Mabel; Ferris, Gloria

    2010-01-01

    Mabel Cooper and Gloria Ferris spent their early adult life in St. Lawrence's Hospital in Caterham. This was in the late 1950s to early 1970s. This is their memories of how they spent their time. It includes the work they did and leisure. They also write about the tokens that were used in the hospital instead of money.

  2. RAPID COMMUNICATION Microplastic pollution in St. Lawrence River sediments

    E-print Network

    Ricciardi, Anthony

    RAPID COMMUNICATION Microplastic pollution in St. Lawrence River sediments Rowshyra A. Castañeda ecosystems, microplastic pollution has only recently been documented in freshwater environments, almost exclusively in surface waters. Here, we report microplastics (polyethylene microbeads, 0.40­ 2.16 mm diameter

  3. St. Lawrence River Freeze-Up Forecast Procedure.

    ERIC Educational Resources Information Center

    Assel, R. A.

    A standard operating procedure (SOP) is presented for calculating the date of freeze-up on the St. Lawrence River at Massena, N.Y. The SOP is based on two empirical temperature decline equations developed for Kingston, Ontario, and Massena, N.Y., respectively. Input data needed to forecast freeze-up consist of the forecast December flow rate and…

  4. The influence of wind and ice on spring walrus hunting success on St. Lawrence Island, Alaska

    E-print Network

    Zhang, Jinlun

    The influence of wind and ice on spring walrus hunting success on St. Lawrence Island, Alaska Henry Available online 14 March 2013 Keywords: Pacific walrus (Odobenus rosmarus divergens) Hunting St. Lawrence Yupik hunters on St. Lawrence Island, Alaska, take hundreds of Pacific walrus (Odobenus rosmarus

  5. Invasion by stages in the St Louis River estuary

    EPA Science Inventory

    The St. Louis River estuary is recognized as an invasive species “hotspot” - the harbor ranks among the top locations in the Great Lakes reporting the first occurrence of new, aquatic non-native species. To date, 18 non-native benthic invertebrate, 4 non-native crusta...

  6. A Seaway Acoustic Observatory in Action: The St. Lawrence Seaway.

    PubMed

    Simard, Yvan; Roy, Nathalie; Gervaise, Cédric; Giard, Samuel

    2016-01-01

    A setup for measuring spectral source levels (SSLs) of ships transiting along a seaway, the traffic density and shipping noise, is presented. The results feed shipping-noise modeling that reproduces the actual in situ observations to map shipping-noise variability over space and time for investigating its effects on aquatic organisms. The ship's SSL databank allows sorting the different contributors to total shipping noise for assisting in exploring mitigation approaches (e.g., fleet composition, rerouting). Such an acoustic observatory was deployed since November 2012 for a complete annual cycle of measurements in the deep downstream part of the St. Lawrence Seaway. PMID:26611065

  7. 77 FR 30443 - Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ...The Captain of the Port Buffalo has determined that fireworks...It would encompass all waters of St. Lawrence River...the Captain of the Port Buffalo or his on-scene representative...zone will encompass all waters of the St. Lawrence...the Captain of the Port Buffalo or his designated...

  8. 77 FR 38488 - Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    ...display will be held on the waters of the St. Lawrence...The Captain of the Port Buffalo has determined that fireworks...the Captain of the Port Buffalo has determined that a...zone will encompass all waters of the St. Lawrence...the Captain of the Port Buffalo or his designated...

  9. A Practical Grammar of the St. Lawrence Island/Siberian Yupik Eskimo Language. Preliminary Edition.

    ERIC Educational Resources Information Center

    Jacobson, Steven A.

    The grammar of the St. Lawrence Island/Siberian Yupik Eskimo language was written for college-level classes containing a mixture of Yupik speakers and non-speakers, and for students learning the language on their own. It uses only the Central Siberian Yupik dialect spoken on St. Lawrence Island (Alaska) and on a small portion of the Asian…

  10. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat...

  11. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat...

  12. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat...

  13. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat...

  14. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat...

  15. Impact of the Dreissena invasion on native unionid bivalves in the upper St. Lawrence River

    E-print Network

    Ricciardi, Anthony

    Impact of the Dreissena invasion on native unionid bivalves in the upper St. Lawrence River A and Dreissena bugensis) colonized native unionid bivalves in the upper St. Lawrence River in the early 1990s et Dreissena bugensis) introduites ont colonisé des bivalves de la famille des unionidés, indigènes

  16. NOAA Technical Memorandum ERL GLERL-104 GREAT LAKES AND ST. LAWRENCE RIVER MEDIUM RESOLUTION VECTOR

    E-print Network

    NOAA Technical Memorandum ERL GLERL-104 GREAT LAKES AND ST. LAWRENCE RIVER MEDIUM RESOLUTION VECTOR SHORELINE DATA D.H. LEE NOAA, Great Lakes Environmental Research Laboratory, Ann Arbor, MI C. MORSE, and S ............................................................................................................................................. 4 2. Great Lakes-St. Lawrence River Vector Shoreline Data

  17. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and...679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat Conservation Area Longitude Latitude 16824.00W...

  18. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and...679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat Conservation Area Longitude Latitude 16824.00W...

  19. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and...679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat Conservation Area Longitude Latitude 16824.00W...

  20. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and...679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat Conservation Area Longitude Latitude 16824.00W...

  1. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and...679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat Conservation Area Longitude Latitude 16824.00W...

  2. History of atmospheric trace metal deposition along the St. Lawrence Valley (Quebec) using peat bog

    E-print Network

    History of atmospheric trace metal deposition along the St. Lawrence Valley (Quebec) using peat bog and peat bogs. Among these archives, peat bogs have proven to be effective in reconstructing the history three peat bogs along the St. Lawrence Valley. Core chronologies were established using 210 Pb

  3. Parameterization, regionalization and radiative transfer coherence of optical measurements acquired in the St-Lawrence ecosystem

    NASA Astrophysics Data System (ADS)

    Cizmeli, Servet Ahmet

    In-water biogeochemical constituents and bio-optical properties of the St-Lawrence Gulf and Estuary were monitored during 5 cruises conducted between 1997-2001 accross different seasons. Measured inherent optical properties (IOPs) included vertical profiles of the absorption and attenuation coefficients and the volume scattering function as well as absorption by particles, non-algal particles, phytoplankton and coloured dissolved organic matter (CDOM). Apparent Optical parameters (AOPs) included vertical profiles of the upwelling radiance and downwelling irradiance. The spectral shape of the major IOPs like absorption by phytoplankton, CDOM and non-algal particles as well as the particulate backscattering were parameterized using conventional models and adaptations of conventional models. Descriptive statistics of each variable in the collected dataset were analysed and compared with previous findings in the literature. The optical coherence of the measurements was verified using a radiative transfer closure approach. A complete set of IOP cross-sections for optically significant biogeochemical variables were generated. The magnitude and the spatial, temporal and spectral variation exhibited by the optically significant inwater biogeochemical constituents as well as the bio-optical parameters was consistent with our current knowledge of the ecosystem. The variation of the bio-optical parameters throughout the seasons was also coherent with our expectations. All the measured and derived parameters were found to vary within the ranges reported in the literature. Evidence was presented wherein the Gulf waters, which are usually considered as case I waters could also behave like case II waters. Moreover, spectral signatures exhibited by the IOPs and AOPs were coherent with the variation detected in the concentrations of the measured (optically significant) constituents. The extracted IOP cross-sections were consistent with the results of similar studies previously performed and could eventually be used in the estimation of the biogeochemical constituent concentrations given the related component IOPs. First-order radiative transfer closure was achieved; this underscored the validity of our experimental dataset based on considerations of higher level, integrative, physics. We argue that the current data collection campaign succeeded as a comprehensive framework for describing the behavior of the St-Lawrence bio-optical provinces within the context of remote sensing objectives. This bio-optical dataset should provide the basis for the development of a rigorous, satellite-based, remote sensing algorithm for the retrieval of near surface chlorophyll, fine-tuned to the local characteristics of the St-Lawrence system. Keywords. Phytoplankcton, bio-optical parameter, coloured dissolved organic matter, Apparent Optical parameter, inherent optical properties, radiative transfert, case II waters, suspended matter.

  4. Characterization of St. Lawrence blue whale vocalizations and their correlation with field observations

    NASA Astrophysics Data System (ADS)

    Berchok, Catherine L.

    During four field seasons from 1998--2001, 115 hours of acoustic recordings were made in the presence of the well-studied St. Lawrence population of blue whales. The primary field site for this study was the estuary region of the St. Lawrence River (Quebec, Canada) with most recordings made between mid-August and late October. Effort was concentrated in the daylight hours, although occasionally extending past nightfall. An inexpensive and portable recording system was built that was easy to deploy and provided quality recordings in a variety of sea conditions. It consisted of a calibrated omni-directional hydrophone with a flat (+/-3dB) response from 5Hz to 800Hz; and a surface isolation buoy to minimize the vertical movement of the sensor. During the recording sessions detailed field notes were taken on all blue whales within sight, with individual identities confirmed through photo-identification work between sessions. Notes were also taken on all other species sighted during the recording sessions. Characterization of the more than one-thousand blue whale calls detected during this study revealed that the St. Lawrence repertoire is much more extensive than previously reported. Three infrasonic (<20Hz) and four audible range (30--200Hz) call types were detected in this study, with much time/frequency variation seen within each type. The infrasonic calls were long (5--30s) in duration and arranged into regularly patterned series. These calls were similar in call characteristics and spacing to those detected in the North Atlantic, but had much shorter and more variable patterned series. The audible call types were much shorter (1--4s), and occurred singly or in irregularly spaced clusters, although a special patterning was seen that contained both regular and irregular spaced components. Comparison of the daily, seasonal, and spatial distributions of calling behavior with those of several biological parameters revealed interesting differences between the three call types examined. The trends seen suggest a migratory, reproductive, or foraging context for the infrasonic calls. A closer-range social context is suggested for the audible downsweeps, which have been detected in foraging situations as well as in courtship displays. The audible mixed-pattern call type appears to have a primarily reproductive context.

  5. Earthquakes and Geological Structures of the St. Lawrence Rift System

    NASA Astrophysics Data System (ADS)

    Lamontagne, M.; Ranalli, G.

    2013-12-01

    The St. Lawrence Rift System (SLRS), which includes the Ottawa-Bonnechère and Saguenay grabens, is located well inside the North American plate. Most historic and the some 350 earthquakes recorded yearly occur in three main seismically active zones, namely Charlevoix (CSZ), Western Quebec (WQSZ), and Lower St. Lawrence (LSLSZ)). Outside these areas, most of the Canadian Shield and bordering regions have had a very low level of earthquake activity. In the SLRS, moderate to large earthquakes (Moment magnitude (M) 5.5 to M 7) are known to have occurred since 1663 causing landslides and damage mostly to unreinforced masonry elements of buildings located on ground capable of amplifying ground motions. Most earthquakes in these seismic zones share common characteristics such as mid- to upper crustal focal depths, no known surface ruptures and proximity to SLRS faults. Variations also exist such as vast seismically-active region (WQSZ and LSLSZ), presence of a large water body (CSZ and LSLSZ), and absence of SLRS faults near concentration of earthquakes (WQSZ). The CSZ is the best studied seismic zone and there, earthquakes occur in the Canadian Shield, mostly in a 30 X 85 km rectangle elongated along the trend of the St. Lawrence River with local variations in focal depth distribution. Faults related to the SLRS and to a meteor impact structure exist and earthquakes occur along the SLRS faults as well as in between these faults. Overall, the SLRS faults are probably reactivated by the larger earthquakes (M ? 4.5) of the 20th century (CSZ in 1925; WQCSZ in 1935 and 1944; Saguenay in 1988) for which we have focal mechanisms. We propose that caution be exercised when linking historical events that have uncertain epicentres with SLRS faults. Similarly, SLRS faults should not be necessarily considered to be the reactivated structures for most small to moderate earthquakes (M < 4.5). A good example of this is the earthquakes of the WQSZ that tend to concentrate in a well-defined NW-SE alignment with no obvious geological control, except perhaps, a hypothetical hotspot track. Two local factors can lead to the occurrence of SLRS earthquakes: weak faults or enhanced stress levels. We propose that local conditions, concentrated in a few seismic zones, can alter these factors and lead to the occurrence of earthquakes, especially those with M < 4.5. At a continent-wide scale, the correlation between the SLRS and earthquakes is appealing. We suggest, however, that pre-existing faults related to the SLRS do not explain all features of the seismicity. Seismicity is concentrated in more active areas, some with conspicuous normal faults and some with suspected weakening mechanisms such as intense pre-fracturing (e.g. due to a meteorite impact), the passage over a hot spot, or the presence of intrusions and lateral crustal density variations.

  6. Vertical distribution and diel migration of macrozooplankton in the St. Lawrence marine system (Canada) in relation with the cold intermediate layer thermal properties

    NASA Astrophysics Data System (ADS)

    Harvey, Michel; Galbraith, Peter S.; Descroix, Aurélie

    2009-01-01

    Vertical distribution of various species and stages of macrozooplankton (euphausiacea, chaetognatha, cnidaria, mysidacea, amphipoda) were determined for different times of the day and related to the physical environment. Stratified sampling with the BIONESS was carried out during seven cruises in spring and fall 1998, 2000, and 2001, and fall 1999, in two different habitats in the St. Lawrence marine system: the lower St. Lawrence Estuary and the NW Gulf of St. Lawrence. Our results indicate that the various macrozooplankton species were distributed throughout the whole water column including the surface layer, the cold intermediate layer (CIL), and the deep layer at different times of day and night in both areas during all periods. Moreover, three types of migrational patterns were observed within this zooplanktonic community: (1) nocturnal ascent by the whole population, (2) segregation into two groups; one which performed nocturnal accent and another which remained in the deep, and (3) no detectable migration. We also observed that the diel vertical migration (DVM) amplitude in most of the macrozooplankton species varied as a function of physical factors, in particular the spatio-temporal variations of the CIL thermal properties, including the upper and the lower limits of the CIL and the depth of the CIL core temperature. Finally, the different DVM patterns coupled with estuarine circulation patterns and bottom topography could place animals in different flow regimes by night and by day and contribute to their retention (aggregation) and/or dispersion in different areas, time of the day, and seasons.

  7. A threatened beluga (Delphinapterus leucas) population in the traffic lane: vessel-generated noise characteristics of the Saguenay-St. Lawrence Marine Park, Canada.

    PubMed

    McQuinn, Ian H; Lesage, Véronique; Carrier, Dominic; Larrivée, Geneviève; Samson, Yves; Chartrand, Sylvain; Michaud, Robert; Theriault, James

    2011-12-01

    The threatened resident beluga population of the St. Lawrence Estuary shares the Saguenay-St. Lawrence Marine Park with significant anthropogenic noise sources, including marine commercial traffic and a well-established, vessel-based whale-watching industry. Frequency-dependent (FD) weighting was used to approximate beluga hearing sensitivity to determine how noise exposure varied in time and space at six sites of high beluga summer residency. The relative contribution of each source to acoustic habitat degradation was estimated by measuring noise levels throughout the summer and noise signatures of typical vessel classes with respect to traffic volume and sound propagation characteristics. Rigid-hulled inflatable boats were the dominant noise source with respect to estimated beluga hearing sensitivity in the studied habitats due to their high occurrence and proximity, high correlation with site-specific FD-weighted sound levels, and the dominance of mid-frequencies (0.3-23 kHz) in their noise signatures. Median C-weighted sound pressure level (SPL(RMS)) had a range of 19 dB re 1 ?Pa between the noisiest and quietest sites. Broadband SPL(RMS) exceeded 120 dB re 1 ?Pa 8-32% of the time depending on the site. Impacts of these noise levels on St. Lawrence beluga will depend on exposure recurrence and individual responsiveness. PMID:22225023

  8. 50 CFR Figure 17 to Part 679 - Northern Bering Sea Research Area and St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Northern Bering Sea Research Area and St. Lawrence Island Habitat Conservation Area 17 Figure 17 to part 679 Wildlife and Fisheries FISHERY... Sea Research Area and St. Lawrence Island Habitat Conservation Area ER25JY08.011...

  9. The future of species invasions in the Great Lakes-St. Lawrence River basin Katie S. Pagnucco a,1

    E-print Network

    Ricciardi, Anthony

    The future of species invasions in the Great Lakes-St. Lawrence River basin Katie S. Pagnucco a,1 as the Great Lakes-St. Lawrence River basin. Over 180 non-native species have become established in the basin extent. Most notably, the continued warming of surface waters of the Great Lakes basin will lift thermal

  10. 50 CFR Figure 17 to Part 679 - Northern Bering Sea Research Area and St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Northern Bering Sea Research Area and St. Lawrence Island Habitat Conservation Area 17 Figure 17 to part 679 Wildlife and...Northern Bering Sea Research Area and St. Lawrence Island Habitat Conservation Area ER25JY08.011 [73 FR 43371,...

  11. Constraints on Lake Agassiz discharge through the late-glacial Champlain Sea (St. Lawrence Lowlands, Canada) using salinity proxies and an estuarine circulation model

    USGS Publications Warehouse

    Katz, B.; Najjar, R.G.; Cronin, T.; Rayburn, J.; Mann, M.E.

    2011-01-01

    During the last deglaciation, abrupt freshwater discharge events from proglacial lakes in North America, such as glacial Lake Agassiz, are believed to have drained into the North Atlantic Ocean, causing large shifts in climate by weakening the formation of North Atlantic Deep Water and decreasing ocean heat transport to high northern latitudes. These discharges were caused by changes in lake drainage outlets, but the duration, magnitude and routing of discharge events, factors which govern the climatic response to freshwater forcing, are poorly known. Abrupt discharges, called floods, are typically assumed to last months to a year, whereas more gradual discharges, called routing events, occur over centuries. Here we use estuarine modeling to evaluate freshwater discharge from Lake Agassiz and other North American proglacial lakes into the North Atlantic Ocean through the St. Lawrence estuary around 11.5 ka BP, the onset of the Preboreal oscillation (PBO). Faunal and isotopic proxy data from the Champlain Sea, a semi-isolated, marine-brackish water body that occupied the St. Lawrence and Champlain Valleys from 13 to 9 ka, indicate salinity fell about 7-8 (range of 4-11) around 11.5 ka. Model results suggest that minimum (1600 km3) and maximum (9500 km3) estimates of plausible flood volumes determined from Lake Agassiz paleoshorelines would produce the proxy-reconstructed salinity decrease if the floods lasted <1 day to 5 months and 1 month to 2 years, respectively. In addition, Champlain Sea salinity responds very quickly to the initiation (within days) and cessation (within weeks) of flooding events. These results support the hypothesis that a glacial lake flood, rather than a sustained routing event, discharged through the St. Lawrence Estuary during the PBO. ?? 2011 Elsevier Ltd.

  12. The Oligochaeta (Annelida, Clitellata) of the St. Lawrence Great Lakes region: An update

    USGS Publications Warehouse

    Spencer, Douglas R.; Hudson, Patrick L.

    2003-01-01

    An updated oligochaete species list for the Great Lakes region is provided. The list was developed through the reexamination of the taxa reported in a previous report in 1980, addition of new taxa or records collected from the region since 1980, and an update of taxonomy commensurate with systematic and nomenclatural changes over the intervening years since the last review. The authors found 74 papers mentioning Great Lakes oligochaete species. The majority of these papers were published in the 1980s. The literature review and additional collections resulted in 15 species being added to the previous list. Nine taxa were removed from the previous list due to misidentification, synonymies, level of identification, or inability to confirm the identity. Based on this review, 101 species of Oligochaeta are now known from the St. Lawrence Great Lakes watershed. Of these, 95 species are known from the St. Lawrence Great Lakes proper, with an additional 6 species recorded from the inland waters of the watershed. The greatest diversity of oligochaete species was found in the inland waters of the region (81) followed by Lake Huron (72), Lake Ontario (65), Lake Erie (64), Lake Superior (63), Lake Michigan (62), St. Marys River (60), Niagara River (49), Saginaw Bay (44), St. Clair River (37), Lake St. Clair (36), St. Lawrence River (27), and the Detroit River (21). Three species are suspected of being introduced, Branchiura sowerbyi, Gianius aquaedulcis, and Ripistes parasita, and two are believed to be endemic, Thalassodrilus hallae and Teneridrilus flexus.

  13. BIOREMEDIATION AND BIORESTORATION OF A CRUDE OIL CONTAMINATED FRESHWATER WETLAND ON THE ST. LAWRENCE RIVER

    EPA Science Inventory

    Biostimulation by nutrient enrichment and phytoremediation were studied for the restoration of an acutely stressed freshwater wetland experimentally exposed to crude oil. The research was carried out along the shores of the St. Lawrence River at Ste. Croix, Quebec, Canada. The ...

  14. POTASSIC MAGMATISM ON ST. LAWRENCE ISLAND, ALASKA, AND CAPE DEZHNEV, NORTHEAST RUSSIA

    E-print Network

    Toro, Jaime

    Cretaceous igneous rocks in the Bering Strait region (fig. 1) form part of a circum-Pacific magmatic, and geochronology of Cretaceous igneous rocks on St. Lawrence Island were initiated to elucidate the geologic rocks, Permian(?) to Triassic gabbroic rocks, Cretaceous plutonic and volcanic rocks, and Quaternary

  15. A Practical Grammar of the St. Lawrence Island/Siberian Yupik Eskimo Language. Second Edition.

    ERIC Educational Resources Information Center

    Jacobson, Steven A.

    This book deals with the Central Siberian Yupik Eskimo language as spoken on St. Lawrence Island, Alaska, an island near the Bering Strait and on the tip of the Asian mainland opposite Russia. This book has been used with college-level classes composed of a mixture of Yupik speakers and well-prepared non-speakers (people who have studied other,…

  16. 77 FR 38488 - Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    ...-366-9826. SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal..., St. Lawrence River, Alexandria Bay, NY in the Federal Register (77 FR 30443). We received no letters..., call or email LT Christopher Mercurio, Chief of Waterway Management, U.S. Coast Guard Sector...

  17. DAMAGE ASSESSMENT STUDIES FOLLOWING THE NEPCO 140 OIL SPILL ON THE ST. LAWRENCE RIVER

    EPA Science Inventory

    The primary objective of this two-and-one half year research effort was to determine the environmental and economic impacts of the NEPCO 140 oil spill. This spill occurred in the freshwater environment of the St. Lawrence River on June 23, 1976. The cleanup operation, which cost ...

  18. Time Series Analysis of Water Level and Temperature in the St Louis River Estuary

    EPA Science Inventory

    Pressure and temperature loggers were deployed at 9 sites in the St Louis River estuary between 6/23 10/31 2011. A reference sensor was place on the shore to correct pressure data. Sensors were paced at <1 m depth in Allouez Bay, Superior Bay, near Hearding Island, WLSSD Bay, th...

  19. Habitat use and trophic position effects on contaminant bioaccumulation in St. Louis River Estuary fishes

    EPA Science Inventory

    The objective of our study was to determine the relationship between fish tissue stable isotope composition and total mercury or polychlorinated biphenyl (PCB) concentrations in the St. Louis River estuary food web. We sampled two resident fishes, Yellow Perch (Perca flavescens) ...

  20. Distribution of submerged aquatic vegetation in the St. Louis River estuary: Maps and models

    EPA Science Inventory

    In late summer of 2011 and 2012 we used echo-sounding gear to map the distribution of submerged aquatic vegetation (SAV) in the St. Louis River Estuary (SLRE). From these data we produced maps of SAV distribution and we created logistic models to predict the probability of occurr...

  1. Marine geology of the St. Lawrence Estuary Guillaume St-Onge

    E-print Network

    of submarine canyons and channels to transfer sediments from the coast to the deeper marine environment of large submarine landslides during the Holocene, changes in sedimentation rates and the significant role were deposited by local sedimentary processes associated with submarine fans, mass wasting

  2. Influence of the St. Lawrence island Polynya upon the Bering Sea benthos

    SciTech Connect

    Grebmeier, J.M.; Cooper, L.W.

    1995-03-15

    The influence of a polynya, a persistent ice-free region, on water column production and subsequent transport to the shallow continental shelf benthos of the Bering Sea was evaluated by studying spatial patterns of organic material deposition, benthic biomass, community sediment metabolism, benthic population structure, and other potential indicators of enhanced organic carbon transport to benthic communities underlying the St. Lawrence Island Polynya. Despite suggestions that polynyas may be important localized centers of primary productions in polar waters, the authors found that the St. Lawrence Island Polynya does not obviously enhance the biomass of benthic communities directly below the polynya. However, southward flowing, baroclinic currents generated as a result of brine injection at the polynya edge do appear to have an influence on the biomass and ecological structure of Bering Sea benthic communities south of St. Lawrence Island. These currents appear to affect mean sediment oxygen consumption, surface organic carbon/nitrogen ratios, total organic content, and bottom water ammonia by sweeping phytodetrital matter south and to the west of the island. A particle-reactive, short-lived, natural radioisotope, {sup 7}Be, used as an indicator of rapid (days to weeks) deposition of particulate material from the water column, was detected only in surface sediments to the southwest of the island, indicating enhancement of particle deposition to the southwest of the island. Finally, the {sup 18}O content of tunicate cellulose was highest in the polynya region, consistent with increased filter feeding in the late winter when the polynya is present. The Anadyr Current, consisting of nutrient-rich, deeper Bering Sea water that is upwelled onto the shelf in the Gulf of Anadyr, flows west to east in the region south of St. Lawrence Island throughout the year and is the major forcing function for high production in the region. 76 refs., 13 figs., 5 tabs.

  3. Influence of the St. Lawrence Island Polynya upon the Bering Sea benthos

    NASA Astrophysics Data System (ADS)

    Grebmeier, Jacqueline M.; Cooper, Lee W.

    1995-03-01

    The influence of a polynya, a persistent ice-free region, on water column production and subsequent transport to the shallow continental shelf benthos of the Bering Sea was evaluated by studying spatial patterns of organic material deposition, benthic biomass, community sediment metabolism, benthic population structure, and other potential indicators of enhanced organic carbon transport to benthic communities underlying the St. Lawrence Island Polynya. Despite suggestions that polynyas may be important localized centers of primary production in polar waters, we found that the St. Lawrence Island Polynya does not obviously enhance the biomass of benthic communities directly below the polynya. However, southward flowing, baroclinic currents generated as a result of brine injection at the polynya edge do appear to have an influence on the biomass and ecological structure of Bering Sea benthic communities south of St. Lawrence Island. These currents appear to affect mean sediment oxygen consumption, surface organic carbon/nitrogen ratios, total organic content, and bottom water ammonia by sweeping phytodetrital matter south and to the west of the island. A particle-reactive, short-lived, natural radioisotope, 7Be, used as an indicator of rapid (days to weeks) deposition of particulate material from the water column, was detected only in surface sediments to the southwest of the island, indicating enhancement of particle deposition to the southwest of the island. Finally, the 18O content of tunicate cellulose was highest in the polynya region, consistent with increased filter feeding in the late winter when the polynya is present, and presumably promoting primary production in the open water. The Anadyr Current, consisting of nutrient-rich, deeper Bering Sea water that is upwelled onto the shelf in the Gulf of Anadyr, flows west to east in the region south of St. Lawrence Island throughout the year and is the major forcing function for high production in the region. The interaction of Anadyr Water with the winter/spring ephemeral polynya and associated baroclinic currents combine to positively influence benthic communities.

  4. Genetics and shell morphometrics of assimineids (Mollusca, Caenogastropoda, Truncatelloidea) in the St Lucia Estuary, South Africa

    PubMed Central

    Miranda, Nelson A. F.; van Rooyen, Ryan; MacDonald, Angus; Ponder, Winston; Perissinotto, Renzo

    2014-01-01

    Abstract The Assimineidae are a family of amphibious microgastropods that can be mostly found in estuaries and mangroves in South Africa. These snails often occur in great numbers and are ecologically important to the St Lucia Estuary, which forms a crucial part of the iSimangaliso Wetland Park, a UNESCO World Heritage Site. Genetic and shell morphometric analyses were conducted on individuals collected from nine localities distributed from the northern lake regions to the southern lake and the mouth of the St Lucia estuarine lake. Mitochondrial (COI) and nuclear (28S) DNA was used to construct Bayesian Inference, Neighbour-joining, Maximum Parsimony and Maximum Likelihood trees. Principal Component Analysis and Cluster Analysis were performed on standard shell parameter data. Results indicate that two different taxa are present in St Lucia. The taxon comprising individuals from the South Lake and St Lucia Estuary Mouth is identified as Assiminea cf. capensis Bartsch, in accordance with the latest taxonomic consensus. The taxon comprising assimineid individuals from False Bay, North Lake and South Lake, is here tentatively named “Assiminea” aff. capensis (Sowerby). These two taxa exhibit patterns of spatial overlap that appear to vary depending on environmental parameters, particularly salinity. The need to resolve the complex taxonomy of assimineids is highlighted. PMID:25061361

  5. Formation and distribution of sea ice in the Gulf of St. Lawrence: A process-oriented study using a coupled ocean-ice model

    NASA Astrophysics Data System (ADS)

    Urrego-Blanco, Jorge; Sheng, Jinyu

    2014-10-01

    A coupled ocean-ice model for the eastern Canadian shelf is used to examine main physical processes affecting sea ice conditions in the Gulf of St. Lawrence (GSL) and adjacent waters. The coupled model is based on NEMO and uses OPA9 as the ocean circulation component and LIM2 as the ice model. The coupled model is forced by atmospheric reanalysis fields produced by Large and Yeager (2004). The model results are used to examine the roles of thermodynamics and dynamics on sea ice distributions and patterns of ice production and melting, and the influence of ice capping on the circulation in the study region. Analysis of model results indicates that local production of sea ice is important in shallower areas over the northern and western GSL. Equatorward advection of sea ice from the St. Lawrence Estuary is affected significantly by the Gaspé Current. An index is used to quantify the relative importance of thermodynamic and dynamics of sea ice in the GSL. It is found that both thermodynamics and dynamics are important over most of the GSL, except for waters around Anticosti Island, in the southeastern Gulf, and over the eastern Scotian Shelf, where dynamics (or sea ice movements) are the most important mechanism for the presence of sea ice. The study also demonstrates that ice capping significantly reduces the strength of the winter circulation in the GSL.

  6. Mapping ecosystem services in the St. Louis River Estuary

    EPA Science Inventory

    Sustainable management of ecosystems for the perpetual flow of services beneficial to human communities requires reliable data about from where in the ecosystem services flow. Our objective is to map ecosystem services in the St. Louis River with the overarching U.S. EPA goal of ...

  7. Mapping ecosystem services in the St. Louis River estuary (presentation)

    EPA Science Inventory

    Management of ecosystems for sustainable provision of services beneficial to human communities requires reliable data about from where in the ecosystem services flow. Our objective is to map ecosystem services in the St. Louis River with the overarching EPA goal of community sust...

  8. Shark predation on migrating adult American eels (Anguilla rostrata) in the Gulf of St. Lawrence.

    PubMed

    Béguer-Pon, Mélanie; Benchetrit, José; Castonguay, Martin; Aarestrup, Kim; Campana, Steven E; Stokesbury, Michael J W; Dodson, Julian J

    2012-01-01

    In an attempt to document the migratory pathways and the environmental conditions encountered by American eels during their oceanic migration to the Sargasso Sea, we tagged eight silver eels with miniature satellite pop-up tags during their migration from the St. Lawrence River in Québec, Canada. Surprisingly, of the seven tags that successfully transmitted archived data, six were ingested by warm-gutted predators, as observed by a sudden increase in water temperature. Gut temperatures were in the range of 20 to 25°C-too cold for marine mammals but within the range of endothermic fish. In order to identify the eel predators, we compared their vertical migratory behavior with those of satellite-tagged porbeagle shark and bluefin tuna, the only endothermic fishes occurring non-marginally in the Gulf of St. Lawrence. We accurately distinguished between tuna and shark by using the behavioral criteria generated by comparing the diving behavior of these two species with those of our unknown predators. Depth profile characteristics of most eel predators more closely resembled those of sharks than those of tuna. During the first days following tagging, all eels remained in surface waters and did not exhibit diel vertical migrations. Three eels were eaten at this time. Two eels exhibited inverse diel vertical migrations (at surface during the day) during several days prior to predation. Four eels were eaten during daytime, whereas the two night-predation events occurred at full moon. Although tagging itself may contribute to increasing the eel's susceptibility to predation, we discuss evidence suggesting that predation of silver-stage American eels by porbeagle sharks may represent a significant source of mortality inside the Gulf of St. Lawrence and raises the possibility that eels may represent a reliable, predictable food resource for porbeagle sharks. PMID:23082131

  9. The influence of wind and ice on spring walrus hunting success on St. Lawrence Island, Alaska

    NASA Astrophysics Data System (ADS)

    Huntington, Henry P.; Noongwook, George; Bond, Nicholas A.; Benter, Bradley; Snyder, Jonathan A.; Zhang, Jinlun

    2013-10-01

    St. Lawrence Island Yupik hunters on St. Lawrence Island, Alaska, take hundreds of Pacific walrus (Odobenus rosmarus divergens) each year. The harvest and associated effort (hunting trips taken), however, are variable from year to year and also from day to day, influenced by physical environmental factors among other variables. We used data from 1996 to 2010 to construct generalized additive models (GAMs) to examine several relationships among the variables. Physical factors explained 18% of the variability in harvest in Savoonga and 25% of the variability in effort; the corresponding figures for Gambell were 24% and 32%. Effort alone explained 63% of the harvest in Savoonga and 59% in Gambell. Physical factors played a relatively smaller role in determining hunting efficiency (walrus taken per hunting trip), explaining 15% of the variability in efficiency in Savoonga and 22% in Gambell, suggesting that physical factors play a larger role in determining whether to hunt than in the outcome of the hunt once undertaken. Combining physical factors with effort explained 70% of the harvest variability in Savoonga and 66% in Gambell. Although these results indicate that other factors (e.g. fuel prices, socioeconomic conditions) collectively cause a greater share of variability in harvest and effort than ice and wind, at least as indicated by the measures used as predictors in the GAMs, they also suggest that environmental change is also likely to influence future harvest levels, and that climate models that yield appropriately scaled data on ice and wind around St. Lawrence Island may be of use in determining the magnitude and direction of those influences.

  10. Shark Predation on Migrating Adult American Eels (Anguilla rostrata) in the Gulf of St. Lawrence

    PubMed Central

    Béguer-Pon, Mélanie; Benchetrit, José; Castonguay, Martin; Aarestrup, Kim; Campana, Steven E.; Stokesbury, Michael J. W.; Dodson, Julian J.

    2012-01-01

    In an attempt to document the migratory pathways and the environmental conditions encountered by American eels during their oceanic migration to the Sargasso Sea, we tagged eight silver eels with miniature satellite pop-up tags during their migration from the St. Lawrence River in Québec, Canada. Surprisingly, of the seven tags that successfully transmitted archived data, six were ingested by warm-gutted predators, as observed by a sudden increase in water temperature. Gut temperatures were in the range of 20 to 25°C—too cold for marine mammals but within the range of endothermic fish. In order to identify the eel predators, we compared their vertical migratory behavior with those of satellite-tagged porbeagle shark and bluefin tuna, the only endothermic fishes occurring non-marginally in the Gulf of St. Lawrence. We accurately distinguished between tuna and shark by using the behavioral criteria generated by comparing the diving behavior of these two species with those of our unknown predators. Depth profile characteristics of most eel predators more closely resembled those of sharks than those of tuna. During the first days following tagging, all eels remained in surface waters and did not exhibit diel vertical migrations. Three eels were eaten at this time. Two eels exhibited inverse diel vertical migrations (at surface during the day) during several days prior to predation. Four eels were eaten during daytime, whereas the two night-predation events occurred at full moon. Although tagging itself may contribute to increasing the eel's susceptibility to predation, we discuss evidence suggesting that predation of silver-stage American eels by porbeagle sharks may represent a significant source of mortality inside the Gulf of St. Lawrence and raises the possibility that eels may represent a reliable, predictable food resource for porbeagle sharks. PMID:23082131

  11. Age and growth of lake sturgeon in the upper St. Lawrence River

    USGS Publications Warehouse

    Johnson, J.H.; Dropkin, D.S.; LaPan, S.R.; McKenna, J.E., Jr.; Klindt, R.M.

    1998-01-01

    The growth of lake sturgeon (Acipenser fulvescens) over time in the upper St. Lawrence River was examined. Growth of lake sturgeon collected during 1993 and 1994 below Robert Moses Dam near Massena, New York, was compared to that reported for the same population almost 25 years earlier. The data suggest that lake sturgeon growth was similar to that reported in the previous study. However, significant differences in the elevations of regression models between males and fish of unknown sex in both data sets suggest possible sexual dimorphism in growth at younger ages.

  12. Middle pleistocene mollusks from St. Lawrence Island and their significance for the paleo-oceanography of the Bering Sea

    USGS Publications Warehouse

    Hopkins, D.M.; Rowland, R.W.; Patton, W.W., Jr.

    1972-01-01

    Drift, evidently of Illinoian age, was deposited on St. Lawrence Island at the margin of an ice cap that covered the highlands of the Chukotka Peninsula of Siberia and spread far eastward on the continental shelf of northern Bering Sea. Underlying the drift on the northwestward part of the island are mollusk-bearing beds deposited during the Kotzebuan Transgression. A comparison of mollusk faunas from St. Lawrence Island, Chukotka Peninsula, and Kotzebue Sound suggests that the present northward flow through Bering and Anadyr Straits was reversed during the Kotzebuan Transgression. Cold arctic water penetrated southward and southwestward bringing an arctic fauna to the Gulf of Anadyr. Warmer Pacific water probably entered eastern Bering Sea, passed eastward and northeastward around eastern and northern St. Lawrence Island, and then became entrained in the southward currents that passed through Anadyr Strait. ?? 1972.

  13. Late Stage 5 Glacio-isostatic Sea in the St. Lawrence Valley, Canada and United States

    NASA Astrophysics Data System (ADS)

    Occhietti, Serge; Balescu, Sanda; Lamothe, Michel; Clet, Martine; Cronin, Thomas; Ferland, Pierre; Pichet, Pierre

    1996-03-01

    Although post-glacial marine sediments of late Wisconsinan and early Holocene age are common in eastern Canada and the northeastern United States, remnants of older Pleistocene marine sediments are scarce. A fossiliferous marine clay that predates the classical Wisconsinan was recently discovered in the St. Lawrence Valley. A dominantly estuarine environment is inferred from the geochemistry of the shells (? 18O = -7.1) and from benthic foraminifer and ostracode assemblages. The clay indicates a marine invasion (Cartier Sea) shallower and probably shorter than that during the upper late Wisconsinan Champlain Sea episode (12,000-9,500 yr B.P.). The pollen content shows that regional vegetation during the marine episode began as open tundra, then became a Betulaand Alnus crispaforest, reached a climatic optimum with Quercus, Corylus,and Abies,and concluded as a Pinus/Piceaboreal forest. A corrected infrared stimulated luminescence age of 98,000 ± 9000 yr is compatible with the epimerization ratio of shells. The Cartier Sea resulted from a post-glacial glacio-isostatic marine invasion in the St. Lawrence lowlands. It probably occurred during late stage 5 and is tentatively assigned to the transition of oxygen isotope substages 5b/5a. This marine episode dates to stage 5 of the preceding continental glacier which extended to middle latitudes in NE America.

  14. Organochlorine and metal contaminants in traditional foods from St. Lawrence Island, Alaska.

    PubMed

    Welfinger-Smith, Gretchen; Minholz, Judith L; Byrne, Sam; Waghiyi, Vi; Gologergen, Jesse; Kava, Jane; Apatiki, Morgan; Ungott, Eddie; Miller, Pamela K; Arnason, John G; Carpenter, David O

    2011-01-01

    Marine mammals (bowhead whale, walrus, and various seals) constitute the major component of the diet of the Yupik people of St. Lawrence Island, Alaska. St. Lawrence Island residents have higher serum concentrations of polychlorinated biphenyls (PCB) than in the general U.S. population. In order to determine potential sources, traditional food samples were collected from 2004 to 2009 and analyzed for PCBs, three chlorinated pesticides, and seven heavy metals (mercury, copper, zinc, arsenic, selenium, cadmium, and lead). Concentrations of PCB in rendered oils (193-421 ppb) and blubber (73-317 ppb) from all marine mammal samples were at levels that trigger advisories for severely restricted consumption, using U.S. Environmental Protection Agency (EPA) fish consumption advisories. Concentrations of pesticides were lower, but were still elevated. The highest PCB concentrations were found in polar bear (445 ppb) and the lowest in reindeer adipose tissue (2 ppb). Marine mammal and polar bear meat in general have PCB concentrations that were 1-5% of those in rendered oils or adipose tissue. PCB concentrations in organs were higher than meat. Concentrations of metals in oils and meats from all species were relatively low, but increased levels of mercury, cadmium, copper, and zinc were present in some liver and kidney samples. Mercury and arsenic were found in lipid-rich samples, indicating organometals. These results show that the source of the elevated concentrations of these contaminants in the Yupik population is primarily from consumption of marine mammal blubber and rendered oils. PMID:21797772

  15. Hindcast storm events in the Bering Sea for the St. Lawrence Island and Unalakleet Regions, Alaska

    USGS Publications Warehouse

    Erikson, Li H.; McCall, Robert T.; van Rooijen, Arnold; Norris, Benjamin

    2015-01-01

    This study provides viable estimates of historical storm-induced water levels in the coastal communities of Gambell and Savoonga situated on St. Lawrence Island in the Bering Sea, as well as Unalakleet located at the head of Norton Sound on the western coast of Alaska. Gambell, Savoonga, and Unalakleet are small Native Villages that are regularly impacted by coastal storms but where little quantitative information about these storms exists. The closest continuous water-level gauge is at Nome, located more than 200 kilometers from both St. Lawrence Island and Unalakleet. In this study, storms are identified and quantified using historical atmospheric and sea-ice data and then used as boundary conditions for a suite of numerical models. The work includes storm-surge (temporary rise in water levels due to persistent strong winds and low atmospheric pressures) modeling in the Bering Strait region, as well as modeling of wave runup along specified sections of the coast in Gambell and Unalakleet. Modeled historical water levels are used to develop return periods of storm surge and storm surge plus wave runup at key locations in each community. It is anticipated that the results will fill some of the data void regarding coastal flood data in western Alaska and be used for production of coastal vulnerability maps and community planning efforts.

  16. Late Stage 5 Glacio-isostatic Sea in the St. Lawrence Valley, Canada and United States

    USGS Publications Warehouse

    Occhietti, S.; Balescu, S.; Lamothe, M.; Clet, M.; Cronin, T.; Ferland, P.; Pichet, P.

    1996-01-01

    Although post-glacial marine sediments of late Wisconsinan and early Holocene age are common in eastern Canada and the northeastern United States, remnants of older Pleistocene marine sediments are scarce. A fossiliferous marine clay that predates the classical Wisconsinan was recently discovered in the St. Lawrence Valley. A dominantly estuarine environment is inferred from the geochemistry of the shells (??18O = -7.1) and from benthic foraminifer and ostracode assemblages. The clay indicates a marine invasion (Cartier Sea) shallower and probably shorter than that during the upper late Wisconsinan Champlain Sea episode (12,000-9,500 yr B.P.). The pollen content shows that regional vegetation during the marine episode began as open tundra, then became a Betula and Alnus crispa forest, reached a climatic optimum with Quercus, Corylus, and Abies, and concluded as a Pinus/Picea boreal forest. A corrected infrared stimulated luminescence age of 98,000 ?? 9000 yr is compatible with the epimerization ratio of shells. The Cartier Sea resulted from a post-glacial glacio-isostatic marine invasion in the St. Lawrence lowlands. It probably occurred during late stage 5 and is tentatively assigned to the transition of oxygen isotope substages 5b/5a. This marine episode dates to stage 5 of the preceding continental glacier which extended to middle latitudes in NE America. ?? 1996 University of Washington.

  17. Paleomagnetism of Fluorite Veins in the Devonian St. Lawrence Granite and Regional Tectonism of the Avalon Terrane, Newfoundland, Canada.

    NASA Astrophysics Data System (ADS)

    Kawasaki, K.; Symons, D. T.

    2008-05-01

    The St. Lawrence fluorite veins within the Devonian St. Lawrence Granite and its related porphyry dikes constitute a major high-grade resource of fluorspar in Canada. Paleomagnetic analysis of 359 specimens from 29 sites, including both fluorite veins and granite, shows that there is no statistically significant difference at 95% confidence between the site mean characteristic remanent magnetization (ChRM) directions carried by pyrrhotite and/or magnetite of the veins and the granite. There is no evidence of a post-emplacement metamorphic event in the granite or surrounding country rocks. Thus these concordant directions indicate that the granite and fluorite veins are coeval in origin and retain a primary remanence. However, the combined mean ChRM direction of 25 vein and granite sites yields a Middle Pennsylvanian paleopole of ~316 Ma on the North American apparent polar wander path at 35.6°N, 128.8°E (A95 = 3.5°) that is much younger than the 374±2 Ma Devonian U/Pb zircon age for the granite. Structural relationships of two intersecting vertical vein sets indicate that the St. Lawrence Granite has not been tilted since the fluorite veins were formed. Therefore, the difference between the measured and expected paleopoles is interpreted to be the result of a postemplacement counterclockwise rotation of the St. Lawrence Granite region about a vertical axis by ~ 17°. The analysis of Carboniferous paleopoles in the northern Appalachian Orogen indicates that this rotation is Late Devonian.

  18. Historical records of atmospheric metal deposition along the St. Lawrence Valley (eastern Canada) based on peat bog cores

    E-print Network

    ) based on peat bog cores Steve Pratte a,*, Alfonso Mucci a , Michelle Garneau b a GEOTOP and Department bogs Industrial Revolution Lead isotopes Northeastern America a b s t r a c t The recent history short cores collected at three peat bogs along the St. Lawrence Valley (SLV). The onset of industrial

  19. Effects of a major municipal effluent on the St. Lawrence River: A case study.

    PubMed

    Marcogliese, David J; Blaise, Christian; Cyr, Daniel; de Lafontaine, Yves; Fournier, Michel; Gagné, François; Gagnon, Christian; Hudon, Christiane

    2015-05-01

    The St. Lawrence River (SLR) is the second largest waterway in North America. The discharge of the City of Montreal wastewater treatment plant (WWTP) represents the largest volume of treated wastewaters being released into the river. It also ranks as the largest sewage treatment plant of its kind in North America. Over the last decade, intensive multidisciplinary research has focused on assessing the impacts of Montreal wastewater effluents on the SLR. We describe the major findings of these investigations, including the determination of the fate of contaminants, bioaccumulation in fish and invertebrates, ecotoxicological measurements of aquatic animal health, evaluation of endocrine disruption, parasitism in fish, and combined effects of multiple stressors on the SLR. Impacts of the effluents from the WWTP on aquatic organisms from the SLR are both toxicological and ecological, demonstrating the need for an integrated view of the impacts of municipal effluents on aquatic ecosystems. PMID:25416865

  20. Absence of cardiovascular benefits and sportfish consumption among St. Lawrence River anglers.

    PubMed

    Godin, Catherine; Shatenstein, Bryna; Paradis, Gilles; Kosatsky, Tom

    2003-11-01

    The benefits of sportfish consumption and omega-3 fatty acid (omega3-FA) intake for cardiovascular risk factors were evaluated in a sample of 112 male fishers from the St. Lawrence River in the Montreal area during the 1996 winter and fall fishing seasons. A questionnaire on fishing practices and fish consumption was administered, and fasting blood samples were collected for lipid and phospholipid determination. Linear regression analyses, which considered the confounding effect of major risk factors, did not show any significant association between measured omega3-FAs or reported fish intake and blood lipids or blood pressure. This study is limited by its low statistical power due to the small sample size and the possibility that the fish eaten by the participants were low in omega3-FAs or that the participants diets contained foods high in cholesterol-raising fat. PMID:14615233

  1. A survey of the St. Louis River estuary with emphasis on non-indigenous species and habitat structure

    EPA Science Inventory

    As part of a larger study to develop a monitoring network for aquatic non-indigenous species (NIS), a comprehensive multi-gear survey of larval fish and macroinvertebrates in the St. Louis River estuary was conducted during summer 2012. A total of 139 larval fish samples and 118...

  2. Shoreline Classification of the St. Louis River Estuary using Geographic Information Systems and Standard Landuse/Landcover Data Sets

    EPA Science Inventory

    The St. Louis River Estuary (SLRE) shoreline is ~300 km in length and borders MN and WI from the MN highway 23 downstream to Lake Superior. The shoreline is a complex and diverse mixture of many features from industrial docks and slips in the lower SLRE to complex wetlands and na...

  3. Trace metals in the Columbia River Estuary following the 18 May 1980 eruption of Mount St. Helens

    SciTech Connect

    Riedel, G.F.; Wilson, S.L.; Holton, R.L.

    1984-10-01

    Dissolved and suspended concentrations of cadmium, copper, iron, manganese, nickel, lead, and zinc were measured in the Columbia River Estuary following the 18 May 1980 eruption of Mount St. Helens. Soluble concentrations of these trace elements were not substantially elevated by the influx of volcanic ash and mud into the estuary during this period, except for somewhat higher than usual concentrations of manganese and copper. A laboratory experiment indicates that manganese leached from volcanic debris in fresh water and in the transition from fresh to slightly saline water probably caused the elevated Mn leaching from the material into fresh water.

  4. Establishment Patterns of Non-native Fishes: Lessons from the Duluth-Superior Harbor and Lower St. Louis River, an Invasion-prone Great Lakes Freshwater Estuary

    EPA Science Inventory

    The St. Louis River freshwater estuary which drains into western Lake Superior and includes the Duluth-Superior (MN-WI) harbor, has a long history of non-native fish introductions. From 1985 to 2002, seven new fishes were identified in the estuary, an unprecedented rate of non-n...

  5. Oceanography and Quaternary geology of the St. Lawrence Estuary and the Saguenay Fjord

    E-print Network

    resulting from glacial erosion [6]. In the present paper, we describe the main oceanographic features glacial activity. For example, the Laurentian Channel (Figure 1) and the Saguenay Fjord are valleys

  6. Bulk, molecular and spectroscopic analysis of organic matter reactivity classes isolated from St. Lawrence estuary sediment

    E-print Network

    reactivities have been identified within sediments: labile (degraded in oxic/anoxic conditions), non-hydrolyzable. The project then focused on one fraction of particular interest, non-hydrolyzable organic matter (NHOM

  7. Alternative nursery habitat for estuarine associated marine fish during prolonged closure of the St Lucia estuary, South Africa

    NASA Astrophysics Data System (ADS)

    Vivier, Leon; Cyrus, Digby P.

    2009-10-01

    The Mfolozi estuary, located on the east coast of South Africa, was historically directly linked to the adjacent St Lucia estuarine system, the largest estuarine system in Africa and a World Heritage Site. The Mfolozi used to be the main feeder system to maintain lake levels in St Lucia, but increased siltation from sugar cane farming in the Mfolozi floodplain led to artificial separation of the two systems in 1950. Reduced freshwater inflow due to drought conditions caused the St Lucia mouth to remain closed from June 2002 to present, coinciding with low lake levels and hypersaline conditions, except for a brief period during 2007 after the St Lucia mouth breached. These conditions led to disruption of larval recruitment into the system and major changes in biotic communities. Due to the importance of the St Lucia - Mfolozi System link, a study was initiated in 2007 on the fish community of the Mfolozi system, which was sampled using seine and gill nets. The 48 species recorded were dominated by juveniles of marine spawners, particularly Leiognathus equula and Valamugil cunnesius and the estuarine spawners Ambassis dussumieri and Ambassis natalensis. Estuarine dependent marine spawning species formed 68% of both the species numbers and CPUE, an indication of the regional importance of the Mfolozi estuary as an alternate refuge for juvenile marine fish during periods when the St Lucia system remained closed. Post-larval recruits of marine spawning species were particularly abundant, but low zoobenthic densities caused a rapid decline in numbers of benthic feeders shortly after their recruitment into the system. The importance of the Mfolozi estuary in maintaining marine brood stocks of estuarine dependent marine fish is discussed with particular reference to estuarine degradation and the ecological integrity of the St Lucia system.

  8. Novel brominated flame retardants and dechloranes in three fish species from the St. Lawrence River, Canada.

    PubMed

    Houde, Magali; Berryman, David; de Lafontaine, Yves; Verreault, Jonathan

    2014-05-01

    Restrictions in the utilization of polybrominated diphenyl ether (PBDE) mixtures have led to the increased usage of alternative flame retardant additives in a wide range of commercial applications. The present study examined the occurrence of established and emerging flame retardants (FRs) in fish from a densely-populated urbanized sector of the St. Lawrence River (Montreal, Quebec, Canada). Thirty-eight PBDE congeners and sixteen emerging FRs were determined in fish belonging to three predatory species (yellow perch, northern pike, and muskellunge). The ?PBDE in fish were up to 24,115 ng/g lipid weight (l.w.) in the apex predator muskellunge. Twelve emerging FRs including bis(2-ethylhexyl)-tetrabromophthalate (BEHTBP), pentabromoethylbenzene (PBEB), Dechlorane Plus (anti and syn), dechloranes (Dec) 602, Dec 604, Dec 604 Compound B (Dec 604 CB), and Chlordene Plus (CP) were detected (>0.01 ng/gl.w.) in the liver of muskellunge and northern pike but not in yellow perch homogenates. This is the first report of Dec 604 CB in any fish species. The bioavailability of these FRs in human-impacted aquatic ecosystems warrants further environmental assessment and toxicity testing. PMID:24534698

  9. Efficiency of sediment quality guidelines for predicting toxicity: the case of the St. Lawrence River.

    PubMed

    Desrosiers, Mélanie; Babut, Marc P; Pelletier, Magella; Bélanger, Caroll; Thibodeau, Suzie; Martel, Louis

    2010-04-01

    Multitiered frameworks that are designed for risk assessment of contaminated sediment rely on sediment quality guidelines (SQGs) at the first tier or screening level. In the case of contamination by multiple pollutants, results can be aggregated under indices such as the mean quotient. A decision is then reached (e.g., to dispose of dredged materials in open water) without further investigation, provided that the SQGs or the specific values of indices or quotients derived from the SQGs are not exceeded. In this way, SQGs and quotients play a critical role in environmental protection. As part of the development of a tiered framework to assess the environmental risk of materials dredged from the St. Lawrence River, we evaluated various quotients based on SQGs available for this river with a data set that matches chemistry and toxicity test endpoints. The overall efficiency of all tested quotients was rather low, and we then examined factors such as sediment grain size, nutrients, metal-binding phases (e.g., Al, Fe), and dissolved organic carbon to explain misclassified samples. This examination led to the design of a modified tier 1 framework in which SQGs are used in combination with decision rules based on certain explanatory factors. PMID:20821687

  10. Late Quaternary history of the southwestern St. Lawrence Lowlands and adjacent Adirondack Highlands

    SciTech Connect

    Pair, D.L. . Dept. of Geology)

    1993-03-01

    The reconstruction of Late Wisconsinan ice retreat, proglacial lakes, and Champlain Sea history from the northwest Adirondack slope and adjacent St. Lawrence Lowlands is critical to the synthesis of a regional picture of deglacial events in the eastern Great Lakes region. Unfortunately, these same areas are well known for their limited exposures, landforms covered by thick forest, large tracts of land inaccessible to detailed field mapping, and the overall paucity of glacial materials preserved on upland surfaces. Despite these limitations, a model which utilizes multiple and field-truthed evidence has been used to designate areas where ice border deposits indicate a substantial recessional position. It employs the following criteria in this analysis: sedimentology and morphostratigraphy of morainal landform segments and related sediments; orientation and continuity of ice border drainage channels; and the relationship of ice borders and drainage systems to well documented local and regional water bodies which accompanied ice retreat. The results of this approach have provided a unique regional picture of deglaciation. Despite the inherent limitations of working in upland areas to reconstruct glacial events, detailed morphostratigraphic correlations based on multiple lines of evidence can yield important information. The positions of five former ice borders have been reconstructed from the available data. These ice margins correspond closely with those documented previously by others adjoining areas. This type of study, utilizing multiple and field-truthed lines of evidence, constitutes a tangible step towards understanding the nature and history of ice retreat along this portion of the Laurentide Ice Sheet.

  11. Temporal changes in wetland landscapes of a section of the St. Lawrence River, Canada

    NASA Astrophysics Data System (ADS)

    Jean, Martin; Bouchard, André

    1991-03-01

    Historical aerial photographs (from 1946 through 1983) were used to study and describe the nature and extent of changes in wetland vegetation of a section of the St. Lawrence River and to evaluate the relative importance of water level, fire, and vegetational development as causal factors of these historical changes. Data were encoded and analyzed using a geographical information system, autocorrelation, and Mantel tests. Results show three temporal patterns in wetland dynamics. First, some wetland zones have been reduced by human activities (urbanization, landfilling, canal dredging). The second group consists of wetland areas that remain stable and do not change over time. They are generally protected sites artificially maintained by water-level control. A third situation has occurred in the Lake Saint-François National Wildlife Area, where no significant wetland losses were detected, but where landscape structure has changed greatly. Modeling with Mantel tests suggests that, in the latter case, these changes in wetland landscape are related to the suppression of burning (fires set deliberately by Indians) since the purchase of the territory by the Canadian federal government. This situation has caused rapid replacement of wet meadows by Alnus rugosa scrub and a possible decline in habitat diversity.

  12. Characterization of turbidity in Florida's Lake Okeechobee and Caloosahatchee and St. Lucie estuaries using MODIS-Aqua measurements.

    PubMed

    Wang, Menghua; Nim, Carl J; Son, Seunghyun; Shi, Wei

    2012-10-15

    This paper describes the use of ocean color remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to characterize turbidity in Lake Okeechobee and its primary drainage basins, the Caloosahatchee and St. Lucie estuaries from 2002 to 2010. Drainage modification and agricultural development in southern Florida transport sediments and nutrients from watershed agricultural areas to Lake Okeechobee. As a result of development around Lake Okeechobee and the estuaries that are connected to Lake Okeechobee, estuarine conditions have also been adversely impacted, resulting in salinity and nutrient fluctuations. The measurement of water turbidity in lacustrine and estuarine ecosystems allows researchers to understand important factors such as light limitation and the potential release of nutrients from re-suspended sediments. Based on a strong correlation between water turbidity and normalized water-leaving radiance at the near-infrared (NIR) band (nL(w)(869)), a new satellite water turbidity algorithm has been developed for Lake Okeechobee. This study has shown important applications with satellite-measured nL(w)(869) data for water quality monitoring and measurements for turbid inland lakes. MODIS-Aqua-measured water property data are derived using the shortwave infrared (SWIR)-based atmospheric correction algorithm in order to remotely obtain synoptic turbidity data in Lake Okeechobee and normalized water-leaving radiance using the red band (nL(w)(645)) in the Caloosahatchee and St. Lucie estuaries. We found varied, but distinct seasonal, spatial, and event driven turbidity trends in Lake Okeechobee and the Caloosahatchee and St. Lucie estuary regions. Wind waves and hurricanes have the largest influence on turbidity trends in Lake Okeechobee, while tides, currents, wind waves, and hurricanes influence the Caloosahatchee and St. Lucie estuarine areas. PMID:22858282

  13. Study on subtidal circulation and variability in the Gulf of St. Lawrence, Scotian Shelf, and Gulf of Maine using a nested-grid shelf circulation model

    NASA Astrophysics Data System (ADS)

    Urrego-Blanco, Jorge; Sheng, Jinyu

    2014-03-01

    This paper examines the subtidal circulation and associated variability in the Gulf of St. Lawrence, the Scotian Shelf, and the Gulf of Maine (GSL-SS-GOM) in 1988-2004 based on results produced by a nested-grid shelf circulation model. The model has a fine-resolution child model (˜ (1/12)°) embedded inside a coarse-resolution parent model (˜ (1/4)°) of the northwest Atlantic. The combination of the semi-prognostic method and the spectral nudging method is used to reduce the model seasonal bias and drift. The child model reproduces the general features of the observed circulation and hydrography over the study region during the study period. The child model results demonstrate that the time-mean circulation in the GSL is affected by the time-mean atmospheric forcing and inflow through the Strait of Belle Isle. The temporal variability in atmospheric forcing affects the outflow through western Cabot Strait, which in turn affects the transport of the Nova Scotian Current and the gulf-wide cyclonic circulation in the GOM. The simulated seasonal variability of salinity in the top 30 m of the GSL-SS-GOM is mainly affected by the equatorward advection of low-salinity waters from the lower St. Lawrence Estuary to the GOM through the Scotian Shelf. The simulated intraseasonal variability of circulation in the GSL is affected by the variability in the estuarine circulation in response to the temporal variability in atmospheric forcing. On the Scotian Shelf, the intraseasonal variability is mainly driven by the variability of wind forcing and mesoscale and nonlinear dynamics over the shelf break and slope region. The interannual variability in the simulated temperature and salinity are spatially coherent in the intermediate waters in the GSL, which is caused partially by the local response to atmospheric variability and partially by variabilities over the southern Newfoundland Shelf that enter the GSL through the eastern Cabot Strait. By comparison, on the Scotian Shelf, the interannual variability of simulated circulation is affected by anomalies produced by the nonlinear dynamics which are advected equatorwards by the shelf break jet.

  14. Modeling wave-ice interactions in the Gulf of St. Lawrence

    NASA Astrophysics Data System (ADS)

    Bismuth, E.; Dumont, D.; Neumeier, U.

    2013-12-01

    The Gulf of St. Lawrence (GSL) is a seasonally ice-covered basin located in eastern Canada that is subject to coastal erosion through the action of waves. Sea ice contributes in many ways to the prevailing wave conditions and to sediment transport at the coast. It reduces the fetch over which wind waves can grow and it selectively attenuates waves. Simulations of the future climate suggest that the maximum sea ice extent will decrease and that the winter season will shorten significantly, affecting the wave climate and the occurrence of extreme events. In this work we adapt and use a waves-in-ice model (WIM) to study how changing ice conditions will affect the wave conditions at the coast. WIM is an advection-attenuation model for waves propagating in sea ice that calculate the floe size distribution by way of floe breaking. It has been initially developed for swell waves impacting the arctic marginal ice zone (MIZ) and the generation of waves by the wind is not included. In order to simulate wave conditions in the GSL, wind wave generation is added to WIM and the wave spectrum at the coast is studied for various spatial distributions of sea ice and wind conditions. Obtained results are compared with observations from three acoustic wave and current (AWAC) profilers deployed in the GSL for three consecutive winters (2010-2013). This comparison allows us to assess the validity of the model and its parameterizations in seas that are covered with relatively thin ice and subject to modest wave conditions compared to the arctic MIZ.

  15. Anthropogenic stable cesium in water and sediment of a shallow estuary, St. Louis Bay, Mississippi

    NASA Astrophysics Data System (ADS)

    Bera, Gopal; Yeager, Kevin M.; Shim, MooJoon; Shiller, Alan M.

    2015-05-01

    St. Louis Bay (SLB), Mississippi, is a small, shallow estuary with moderate local residential and industrial development. Dissolved, stable Cs (i.e., 133Cs) was significantly enriched in bay waters (up to 1570 nM) as compared to river (<1 nM) and ocean waters (2.3 nM). A TiO2 refinery, located on the north shore of the bay, is the likely source of the Cs, given that the highest Cs concentrations were found in waters and in surface sediments (up to 49 ?g/g) near the refinery outfall. This setting presented a unique opportunity to study remobilization of Cs in a shallow estuarine system, where sediment resuspension is frequent. Remobilization (up to ?3 fold increase) of dissolved Cs was observed during sediment resuspension events. A weak correlation between Cs and clay %; strong correlations among Cs, silt % and particulate organic carbon (POC); and simple numerical approaches indicate that desorption from resuspended particulate matter is the likely mechanism of Cs remobilization. Cs-enriched SLB waters can be traced to nearshore Mississippi Sound waters, but not into Mississippi Bight waters further offshore. The findings from this study also suggest that caution needs to be taken when interpreting the radio-cesium distribution in shallow estuarine and coastal systems.

  16. Aquatic Vegetation of the St. Louis River Estuary: Initial Analysis of Point-intercept Data Collected in 2010 for Restoration Modeling.

    EPA Science Inventory

    A new effort to model aquatic vegetation patterns in the St. Louis River Estuary was initiated in summer of 2010 for the purpose of informing wetland restoration planning in the St. Louis River Area of Concern (AOC) at 40th Avenue West in Duluth. Aquatic vascular plants were doc...

  17. Holocene environmental and parasequence development of the St. Jones Estuary, Delaware (USA): Foraminiferal proxies of natural climatic and anthropogenic change

    USGS Publications Warehouse

    Leorri, E.; Martin, R.; McLaughlin, P.

    2006-01-01

    The benthic foraminiferal record of marshes located along western Delaware Bay (St. Jones Estuary, USA) reflects the response of estuaries to sea-level and paleoclimate change during the Holocene. System tracts are recognized and within them parasequences based on sedimentological and foraminiferal assemblages identification. The parasequences defined by foraminiferal assemblages appear correlative with rapid Holocene climate changes that are of worldwide significance: 6000-5000, 4200-3800, 3500-2500, 1200-1000, and 600??cal years BP. Following postglacial sea-level rise, modern subestuaries and marshes in the region began to develop between 6000 and 4000??years BP, depending on their proximity to the mouth of Delaware Bay and coastal geomorphology. Initial sediments were fluvial in origin, with freshwater marshes established around 4000??years BP. The subsequent sea-level transgression occurred sufficiently slowly that freshwater marshes alternated with salt marshes at the same sites to around 3000??years BP. Locally another two transgressions are identified at 1800 and 1000??years BP respectively. Marine influence increased in the estuaries until 600??years BP (Little Ice Age), when regression occurred. Sea-level began to rise again during the mid-19th Century at the end of the Little Ice Age, when marshes became established. The presence of a sand lens in the upper and middle estuary and the reduction in the number of tests in the top samples in cores from the same area also suggest an anthropogenic influence. The estuary infill resulted in a sharp transgressive sequence, represented by salt marsh foraminiferal assemblages in the upper part of the cores. The increase in marsh foraminifera in both areas suggests an increase in marine influence that might be due to the transgression beginning at the end of the Little Ice Age about 150-180??years ago coupled with anthropogenic straightening of the channel in 1913. ?? 2006 Elsevier B.V. All rights reserved.

  18. Development of a Halotolerant Community in the St. Lucia Estuary (South Africa) during a Hypersaline Phase

    PubMed Central

    Carrasco, Nicola K.; Perissinotto, Renzo

    2012-01-01

    Background The St. Lucia Estuary, Africa's largest estuarine lake, is currently experiencing unprecedented freshwater deprivation which has resulted in a northward gradient of drought effects, with hypersaline conditions in its northern lakes. Methodology/Principal Findings This study documents the changes that occurred in the biotic communities at False Bay from May 2010 to June 2011, in order to better understand ecosystem functioning in hypersaline habitats. Few zooplankton taxa were able to withstand the harsh environmental conditions during 2010. These were the flatworm Macrostomum sp., the harpacticoid copepod Cletocamptus confluens, the cyclopoid copepod Apocyclops cf. dengizicus and the ciliate Fabrea cf. salina. In addition to their exceptional salinity tolerance, they were involved in a remarkably simple food web. In June 2009, a bloom of an orange-pigmented cyanobacterium (Cyanothece sp.) was recorded in False Bay and persisted uninterruptedly for 18 months. Stable isotope analysis suggests that this cyanobacterium was the main prey item of F. cf. salina. This ciliate was then consumed by A. cf. dengizicus, which in turn was presumably consumed by flamingos as they flocked in the area when the copepods attained swarming densities. On the shore, cyanobacteria mats contributed to a population explosion of the staphylinid beetle Bledius pilicollis. Although zooplankton disappeared once salinities exceeded 130, many taxa are capable of producing spores or resting cysts to bridge harsh periods. The hypersaline community was disrupted by heavy summer rains in 2011, which alleviated drought conditions and resulted in a sharp increase in zooplankton stock and diversity. Conclusions/Significance Despite the current freshwater deprivation crisis, the False Bay region has shown to be resilient, harboring a unique biodiversity with species that are capable of enduring harsh environmental conditions. However, further freshwater deprivation may extend beyond the physiological thresholds of this community, as well as other unique biodiversity components which this system sustains. PMID:22238676

  19. Strike-slip interpretation of basin-bounding faults of the St. Lawrence lowlands basin the Quebec City area, Canada

    SciTech Connect

    Shaw, B.R. , Houston, TX )

    1993-05-01

    Traditional structural interpretations of faults identified in the autochthonous, Ordovician platform rocks of the St. Lawrence Lowlands basin of Quebec, Canada, assert that the primary sense of faulting is normal, extensional, and dip-slip in motion. Interpretation of field observations such as the offset of facies boundaries in outcrop, fault surface features, fracture patterns, and fault volume considerations lead directly to difficulties with a mobile crustal bulge model for normal faulting. Newly reprocessed seismic data and well-log correlations support this interpretation and indicate a need for a different model for the deformation of the platform margin. A left-lateral, basement-involved wrench system resolves stratigraphic discordances across fault zones, contradictions in the observed geometry of hanging-wall blocks, problems concerning timing of tectonic events, and the difficulty of using extensional deformation models in a compressional setting. This reinterpretation places the timing of the platform faulting just prior to the arrival of the Taconic thrust sheet. The lateral offset of subsurface and surface depositional facies, fault trace features, well correlations, and seismic expressions document approximately 60 km of left-lateral strike-slip motion in the St. Lawrence Lowlands basin. 30 refs., 14 figs., 1 tab.

  20. Forecasting the Major Influences of Predation and Environment on Cod Recovery in the Northern Gulf of St. Lawrence

    PubMed Central

    Bousquet, Nicolas; Chassot, Emmanuel; Duplisea, Daniel E.; Hammill, Mike O.

    2014-01-01

    The northern Gulf of St. Lawrence (NGSL) stock of Atlantic cod (Gadus morhua), historically the second largest cod population in the Western Atlantic, has known a severe collapse during the early 1990 s and is currently considered as endangered by the Committee on the Status of Endangered Wildlife in Canada. As for many fish populations over the world which are currently being heavily exploited or overfished, urgent management actions in the form of recovery plans are needed for restoring this stock to sustainable levels. Stochastic projections based on a statistical population model incorporating predation were conducted over a period of 30 years (2010–2040) to assess the expected outcomes of alternative fishing strategies on the stock recovery under different scenarios of harp seal (Pagophilus groenlandicus) abundance and environmental conditions. This sensitivity study shows that water temperature is key in the rebuilding of the NGSL cod stock. Model projections suggest that maintaining the current management practice under cooler water temperatures is likely to maintain the species in an endangered status. Under current or warmer conditions in the Gulf of St. Lawrence, partial recovery might only be achieved by significant reductions in both fishing and predation pressure. In the medium-term, a management strategy that reduces catch could be favoured over a complete moratorium so as to minimize socio-economic impacts on the industry. PMID:24523852

  1. Reconnaissance investigation of high-calcium marble in the Beaver Creek area, St. Lawrence County, New York

    USGS Publications Warehouse

    Brown, C. Ervin

    1978-01-01

    Three belts of marble of the Grenville Series were mapped in the Beaver Creek drainage basin, St. Lawrence County, N.Y. One of these, on the west side of Beaver Creek, consists of coarsely crystalline pure calcitic marble that occurs in a zone at least 10 by 0.8 km in extent. Samples of marble show CaCO3 content to be greater than 93 percent, and some samples contain greater than 96 percent, and only small amounts of MgO and Fe203 are present. Marble in two other belts to the east of Beaver Creek are variable in composition, but locally have high content of calcium carbonate material. The marble deposit west of Beaver Creek has a chemical composition favorable for specialized chemical, industrial, and metallurgical uses. Another favorable aspect of the deposit is its proximity to inexpensive water transportation on the St. Lawrence Seaway only 27.5 km away by road, at Ogdensburg, N.Y.

  2. Forecasting the major influences of predation and environment on cod recovery in the northern Gulf of St. Lawrence.

    PubMed

    Bousquet, Nicolas; Chassot, Emmanuel; Duplisea, Daniel E; Hammill, Mike O

    2014-01-01

    The northern Gulf of St. Lawrence (NGSL) stock of Atlantic cod (Gadus morhua), historically the second largest cod population in the Western Atlantic, has known a severe collapse during the early 1990 s and is currently considered as endangered by the Committee on the Status of Endangered Wildlife in Canada. As for many fish populations over the world which are currently being heavily exploited or overfished, urgent management actions in the form of recovery plans are needed for restoring this stock to sustainable levels. Stochastic projections based on a statistical population model incorporating predation were conducted over a period of 30 years (2010-2040) to assess the expected outcomes of alternative fishing strategies on the stock recovery under different scenarios of harp seal (Pagophilus groenlandicus) abundance and environmental conditions. This sensitivity study shows that water temperature is key in the rebuilding of the NGSL cod stock. Model projections suggest that maintaining the current management practice under cooler water temperatures is likely to maintain the species in an endangered status. Under current or warmer conditions in the Gulf of St. Lawrence, partial recovery might only be achieved by significant reductions in both fishing and predation pressure. In the medium-term, a management strategy that reduces catch could be favoured over a complete moratorium so as to minimize socio-economic impacts on the industry. PMID:24523852

  3. Distribution of submerged aquatic vegetation in the St. Louis River estuary: Maps and models (Presentation)

    EPA Science Inventory

    SAV provides the biophysical basis for several ecosystem services in Great Lakes estuaries including rearing and adult habitat for commercially and recreationally important fishes, foraging habit for waterfowl, and nutrient retention. Understanding sources of variation in SAV in ...

  4. Fossil brines preserved in the St-Lawrence Lowlands, Québec, Canada as revealed by their chemistry and noble gas isotopes

    NASA Astrophysics Data System (ADS)

    Pinti, Daniele L.; Béland-Otis, Catherine; Tremblay, Alain; Castro, Maria Clara; Hall, Chris M.; Marcil, Jean-Sébastien; Lavoie, Jean-Yves; Lapointe, Raynald

    2011-08-01

    Brines in Cambrian sandstones and Ordovician dolostones of the St-Lawrence Lowlands at Bécancour, Québec, Canada were sampled for analysis of all stable noble gases in order to trace their origin and migration path, in addition to quantifying their residence time. Major ion chemistry indicates that the brines are of Na-Ca-Cl type, possibly derived from halite dissolution. 87Sr/ 86Sr ratios and Ca excess indicate prolonged interactions with silicate rocks of the Proterozoic Grenville basement or the Cambrian Potsdam sandstone. The brines constrain a 2-3% contribution of mantle 3He and large amounts of nucleogenic 21Ne ? and 38Ar ? and radiogenic 4He and 40Ar ?. 4He/ 40Ar ? and 21Ne ?/ 40Ar ? ratios, corrected for mass fractionation during incomplete brine degassing, are identical to their production ratios in rocks. The source of salinity (halite dissolution), plus the occurrence of large amounts of 40Ar ? in brines constrain the residence time of Bécancour brines as being older than the Cretaceous. Evaporites in the St-Lawrence Lowlands likely existed only during Devonian-Silurian time. Brines might result from infiltration of Devonian water leaching halite, penetrating into or below the deeper Cambrian-Ordovician aquifers. During the Devonian, the basin reached temperatures higher than 250 °C, allowing for thermal maturation of local gas-prone source rocks (Utica shales) and possibly facilitating the release of radiogenic 40Ar ? into the brines. The last thermal event that could have facilitated the liberation of 40Ar ? into fluids and contributed to mantle 3He is the Cretaceous Monteregian Hills magmatic episode. For residence times younger than the Cretaceous, it is difficult to find an appropriate source of salinity and of nucleogenic/radiogenic gases to the Bécancour brines.

  5. Effects of zebra mussels, obtained from Lake Erie and St Lawrence River, as a food source on immune system of lesser scaup

    SciTech Connect

    Flipo, D.; Fournier, M.; Beaulieu, C.; Tessier, C.

    1995-12-31

    A feeding study was undertaken to assess the influence of a zebra mussel diet from Lake Erie and the St.Lawrence river on the immune system of lesser scaup. The Great lakes and the St.Lawrence river are known to be among the most contaminated waters found in the country. Analytical studies have shown that zebra mussels are contaminated by organochlorines and other pollutants. The occurrence of these toxicants in the food diet of lesser scaup can cause serious injuries. The immune system, in its capacity to destroy foreign particles and protect the host against diseases, can serve as a useful sentinel of the health status of these environmentally stressed organisms. Immune parameters of lesser scaup fed with zebra mussels from Lake Erie or the St. Lawrence river were evaluated. The duration of the feeding trial was nine weeks. Phagocytic activity and oxidative bursts of heterophils were evaluated by flow cytometry. Intracellular thiol levels of lymphocytes and heterophils were also determined by flow cytometry. The results showed a dimunition of phagocytic activity and bactericidal potential after 6 weeks of the zebra mussel diet compared to the control. These results may be associated with pathology problems encountered in treated groups at the end of the diet. Birds from the St. Lawrence River group (40%) and the Lake Erie group (40%) demonstrated variable degrees of pododermatitis compared to the control group. The intracellular level of thiol was consistently found to be elevated in lymphocytes and heterophyls from birds feeding with on the St. Lawrence River. In conclusion, flow cytometry assays like phagocytosis, oxidative burst and thiol staining can serve as biomarkers of the immune status of birds and can give important information for evaluating the health of birds exposed to environmental contamination.

  6. Spatial dynamics of biogeochemical processes in the St. Louis River freshwater estuary

    EPA Science Inventory

    In the Great Lakes, river-lake transition zones within freshwater estuaries are hydrologically and biogeochemically dynamic areas that regulate nutrient and energy fluxes between rivers and Great Lakes. The goal of our study was to characterize the biogeochemical properties of th...

  7. Natal origin of atlantic bluefin tuna (thunnus thynnus) from the gulf of st. lawrence using ?13c and ?18o in otoliths 

    E-print Network

    Schloesser, Ryan Walter

    2009-05-15

    ports which were grouped into 3 regions (Caraquet and Tignish = West, Havre Boucher and North Lake = East, St. Margarets Bay = Exterior; Fig. 5, Table 1). Approximately 80% of the specimens were known to be over 250 cm fork length (approximately 15.... Lawrence West GSL East GSL -60? -60? -70? 50 ? 50 ?-70? Caraquet Tignish Havre BoucherHavre Bouche North LakeNorth Lake St. St. Margarets Bay Exterior GSL 0 97 193 290 38648 Kilometers 50 ? 50 ? 20 Table 1. Number of T...

  8. Fish community changes in the St. Louis River estuary, Lake Superior, 1989-1996: Is it ruffe or population dynamics?

    USGS Publications Warehouse

    Bronte, Charles R.; Evrard, Lori M.; Brown, William P.; Mayo, Kathleen R.; Edwards, Andrew J.

    1998-01-01

    Ruffe (Gymnocephalus cernuus) have been implicated in density declines of native species through egg predation and competition for food in some European waters where they were introduced. Density estimates for ruffe and principal native fishes in the St. Louis River estuary (western Lake Superior) were developed for 1989 to 1996 to measure changes in the fish community in response to an unintentional introduction of ruffe. During the study, ruffe density increased and the densities of several native species decreased. The reductions of native stocks to the natural population dynamics of the same species from Chequamegon Bay, Lake Superior (an area with very few ruffe) were developed, where there was a 24-year record of density. Using these data, short- and long-term variations in catch and correlations among species within years were compared, and species-specific distributions were developed of observed trends in abundance of native fishes in Chequamegon Bay indexed by the slopes of densities across years. From these distributions and our observed trend-line slopes from the St. Louis River, probabilities of measuring negative change at the magnitude observed in the St. Louis River were estimated. Compared with trends in Chequamegon Bay, there was a high probability of obtaining the negative slopes measured for most species, which suggests natural population dynamics could explain, the declines rather than interactions with ruffe. Variable recruitment, which was not related to ruffe density, and associated density-dependent changes in mortality likely were responsible for density declines of native species.

  9. 77 FR 30443 - Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ..., issue of the Federal Register (73 FR 3316). Public Meeting We do not now plan to hold a public meeting... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Alexandria Bay Chamber of Commerce, St... during the Alexandria Bay Chamber of Commerce fireworks display. The safety zone established by...

  10. Historical records of atmospheric metal deposition along the St. Lawrence Valley (eastern Canada) based on peat bog cores

    NASA Astrophysics Data System (ADS)

    Pratte, Steve; Mucci, Alfonso; Garneau, Michelle

    2013-11-01

    The recent history of atmospheric As, Cd, Ni, Pb and Zn deposition and the stable Pb isotope signatures were reconstructed from short cores collected at three peat bogs along the St. Lawrence Valley (SLV). The onset of industrial activity was recorded around 1810-1850 AD. As, Cd, Pb and, to a certain extent, Ni deposition rates reached maxima between 1940 and the early 1970s. Trace metals likely originated from coal-burning and ore smelting between 1850 and 1950 AD, and were replaced thereafter, at least in the case of Pb, by the combustion of leaded gasolines until the mid-1980s. Trace metal contents and accumulation rates were greater in the two cores recovered from the southwestern SLV than further northeast, as expected from their proximity to urban and industrial centers of eastern Canada and the U.S. Mid-West and the direction of the prevalent winds. A rapid decrease in metal accumulation rates since the 1970s suggests that mitigation policies were effective in reducing atmospheric metal emissions. Nevertheless, metal accumulation rates and stable Pb isotope signatures have not yet returned to their pre-industrial values.

  11. Biomarkers in zebra mussels (Dreissena polymorpha) for the assessment and monitoring of water quality of the St Lawrence River (Canada).

    PubMed

    de Lafontaine Y; Gagné; Blaise; Costan; Gagnon; Chan

    2000-08-01

    Five biomarkers (MT: metallothionein-like proteins, EROD: ethoxyresorufin ortho-dééthylase, DNA strand breaks, LPO: peroxidation of lipids, VG: vitellogenin-like protiens) were measured in the soft tissues of zebra mussels (Dreissena polymorpha) in order to assess the spatial variation of exposure to contaminants along the St Lawrence River (Canada). Fifteen mussels >25 mm shell length were analyzed from each of the 13 sampling sites. Significant differences between sites were noted for all biomarkers, but the general level of variability was low. Three biomarkers (DNA, LPO and VG) exhibited a similar pattern of spatial variation while MT and EROD had distinct and specific patterns. MT had the strongest discriminating power and EROD showed the largest range of variation among sites. Highest biomarker responses were measured in specimens from local contaminated sites such as harbors and industrial sectors. A positive relationship was found between MT and copper (Cu), but no significant correlation was observed between other biomarker responses and the levels of ten trace metals bioaccumulating in the zebra mussels tissues. Results indicate that the measurement of biomarker responses is technically feasible. The performance of each biomarker is assessed in the context of the role and advantages of selecting a battery of biomarkers for detecting contamination problems. The use of zebra mussels as a sentinel species for biomonitoring potential toxic effects in situ is discussed. PMID:10930650

  12. Estimation, analysis, sources, and verification of consumptive water use data in the Great Lakes-St. Lawrence River basin

    USGS Publications Warehouse

    Snavely, D.S.

    1988-01-01

    The Great Lakes-St. Lawrence River basin provides water for many uses and for wildlife habitat; thus many groups have developed strategies to manage the basin 's water resource. The International Joint Commission (IJC) is reviewing and comparing available consumptive-use data to assess the magnitude and effect of consumptive uses under present projected economic and hydraulic conditions on lake levels. As a part of this effort, the U.S. Geological Survey compared its own estimates of consumptive use in the United States with those generated by (1) the International Great Lakes Diversions and (2) the IJC. The U.S. Geological Survey also developed two methods of calculating consumptive-use projections for 1980 through 2000; one method yields an estimate of 6,490 cu ft/s for the year 2000; the other yields an estimate of 8,330 cu ft/s. These two projections could be considered the upper and lower limits for the year 2000. The reasons for the varying estimates are differences in (1) methods by which base year values were developed, and (2) the methods or models that were used to project consumptive-use values for the future. Acquisition of consumptive-use data from water users or governmental agencies or ministries would be desirable to minimize reliance on estimates. (USGS)

  13. Shipping noise in whale habitat: characteristics, sources, budget, and impact on belugas in Saguenay-St. Lawrence Marine Park hub.

    PubMed

    Gervaise, Cédric; Simard, Yvan; Roy, Nathalie; Kinda, Bazile; Ménard, Nadia

    2012-07-01

    A continuous car ferry line crossing the Saguenay Fjord mouth and traffic from the local whale-watching fleet introduce high levels of shipping noise in the heart of the Saguenay-St. Lawrence Marine Park. To characterize this noise and examine its potential impact on belugas, a 4-hydrophone array was deployed in the area and continuously recorded for five weeks in May-June 2009. The source levels of the different vessel types showed little dependence on vessel size or speed increase. Their spectral range covered 33 dB. Lowest noise levels occurred at night, when ferry crossing pace was reduced, and daytime noise peaked during whale-watching tour departures and arrivals. Natural ambient noise prevailed 9.4% of the time. Ferry traffic added 30-35 dB to ambient levels above 1 kHz during crossings, which contributed 8 to 14 dB to hourly averages. The whale-watching fleet added up to 5.6 dB during peak hours. Assuming no behavioral or auditory compensation, half of the time, beluga potential communication range was reduced to less than ~30% of its expected value under natural noise conditions, and to less than ~15% for one quarter of the time, with little dependence on call frequency. The echolocation band for this population of belugas was also affected by the shipping noise. PMID:22779457

  14. Rewriting the history of an extinction-was a population of Steller's sea cows (Hydrodamalis gigas) at St Lawrence Island also driven to extinction?

    PubMed

    Crerar, Lorelei D; Crerar, Andrew P; Domning, Daryl P; Parsons, E C M

    2014-11-01

    The Kommandorskiye Islands population of Steller's sea cow (Hydrodamalis gigas) was extirpated ca 1768 CE. Until now, Steller's sea cow was thought to be restricted in historic times to Bering and Copper Islands, Russia, with other records in the last millennium from the western Aleutian Islands. However, Steller's sea cow bone has been obtained by the authors from St Lawrence Island, Alaska, which is significantly further north. Bone identity was verified using analysis of mitochondrial DNA. The nitrogen-15 (?(15)N)/carbon-13 (?(13)C) values for bone samples from St Lawrence Island were significantly (p ? 0.05) different from Bering Island samples, indicating a second population. Bone samples were dated to between 1030 and 1150 BP (approx. 800-920 CE). The samples date from close to the beginning of the mediaeval warm period, which could indicate that the population at St Lawrence Island was driven to extinction by climate change. A warming of the climate in the area may have changed the availability of kelp; alternatively or in addition, the animals may have been driven to extinction by the expansion of the Inuit from the Bering Strait region, possibly due to opening waterways, maybe following bowhead whales (Balaena mysticetus), or searching for iron and copper. This study provides evidence for a previously unknown population of sea cows in the North Pacific within the past 1000 years and a second Steller's sea cow extirpation event in recent history. PMID:25428930

  15. Rewriting the history of an extinction—was a population of Steller's sea cows (Hydrodamalis gigas) at St Lawrence Island also driven to extinction?

    PubMed Central

    Crerar, Lorelei D.; Crerar, Andrew P.; Domning, Daryl P.; Parsons, E. C. M.

    2014-01-01

    The Kommandorskiye Islands population of Steller's sea cow (Hydrodamalis gigas) was extirpated ca 1768 CE. Until now, Steller's sea cow was thought to be restricted in historic times to Bering and Copper Islands, Russia, with other records in the last millennium from the western Aleutian Islands. However, Steller's sea cow bone has been obtained by the authors from St Lawrence Island, Alaska, which is significantly further north. Bone identity was verified using analysis of mitochondrial DNA. The nitrogen-15 (?15N)/carbon-13 (?13C) values for bone samples from St Lawrence Island were significantly (p ? 0.05) different from Bering Island samples, indicating a second population. Bone samples were dated to between 1030 and 1150 BP (approx. 800–920 CE). The samples date from close to the beginning of the mediaeval warm period, which could indicate that the population at St Lawrence Island was driven to extinction by climate change. A warming of the climate in the area may have changed the availability of kelp; alternatively or in addition, the animals may have been driven to extinction by the expansion of the Inuit from the Bering Strait region, possibly due to opening waterways, maybe following bowhead whales (Balaena mysticetus), or searching for iron and copper. This study provides evidence for a previously unknown population of sea cows in the North Pacific within the past 1000 years and a second Steller's sea cow extirpation event in recent history. PMID:25428930

  16. From yellow perch to round goby: A review of double-crested cormorant diet and fish consumption at three St. Lawrence River colonies, 1999–2013

    USGS Publications Warehouse

    Johnson, James H.; Farquhar, James F; Klindt, Rodger M; Mazzocchi, Irene; Mathers, Alastair

    2015-01-01

    The number of double-crested cormorants (Phalacrocorax auritus) in the upper St. Lawrence River has increased markedly since the early 1990s. In 1999, a binational study was initiated to examine the annual diet composition and fish consumption of cormorants at colonies in the upper river. Since 1999, 14,032 cormorant pellets, collected from May through September each year, have been examined from St. Lawrence River colonies to estimate fish consumption and determine temporal and spatial variation in diet. Seasonal variation in diet composition within a colony was low. Prior to 2006 yellow perch was the primary fish consumed by cormorants in the upper St. Lawrence River. Round goby were first observed in cormorant diets in 2003 and by 2006 were the main fish consumed at two of the three colonies. The time interval it took from the first appearance of round goby in the diet at a colony to when goby were the dominant prey species varied by island, ranging from two to five years. Daily fish consumption at each cormorant colony increased significantly from the pre-round goby to post-round goby period. The mean annual biomass of yellow perch consumed decreased significantly during the post-round goby period at the three colonies. Reduced consumption of yellow perch by cormorants may alleviate suspected localized impacts on perch near some of the larger river colonies.

  17. Novel flame retardants in urban-feeding ring-billed gulls from the St. Lawrence River, Canada.

    PubMed

    Gentes, Marie-Line; Letcher, Robert J; Caron-Beaudoin, Elyse; Verreault, Jonathan

    2012-09-01

    This study investigated the occurrence of a comprehensive suite of polybrominated diphenyl ethers (PBDEs) and current-use flame retardants (FRs) in ring-billed gulls breeding in a highly industrialized section of the St. Lawrence River, downstream from Montreal (QC, Canada). Despite major point-sources and diffuse contamination by FRs, nearly no FR data have been reported in birds from this area. Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (BEHTBP) was detected in 89% of ring-billed gull livers (mean: 2.16 ng/g ww; max: 17.6 ng/g ww). To our knowledge, this is the highest detection frequency and highest concentrations reported thus far in any avian species or populations. Dechlorane Plus (DP) isomers were also particularly abundant (anti-DP detected in 100% and syn-DP in 93% of livers). Other detected FR compounds (3-14% detection) included 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB), hexachlorocyclopentenyl-dibromocyclooctane (HCDBCO) and ?-1,2-dibromo-4-(1.2-dibromoethyl)-cyclohexane (?-TBECH). Mean BDE-209 (57.2 ± 12.2 ng/g ww) in ring-billed gull livers was unexpectedly high for this midtrophic gull species, exceeding levels reported in several apex raptors such as peregrine falcons. BDE-209's relative contribution to ?PBDEs was on average 25% (exceeding BDE-47 and BDE-99) and contrasted with profiles typically reported for fish-eating gull species. The present study highlighted preoccupying gaps in upcoming FR regulations and stressed the need for further investigation of the sources of FR exposure in highly urbanized areas. PMID:22845168

  18. Hazard assessment of a simulated oil spill on intertidal areas of the St. Lawrence River with SPMD-TOX

    USGS Publications Warehouse

    Johnson, B.T.; Petty, J.D.; Huckins, J.N.; Lee, Kenneth; Gauthier, J.

    2004-01-01

    Phytoremediation in a simulated crude oil spill was studied with a "minimalistic" approach. The SPMD-TOX paradigm - a miniature passive sorptive device to collect and concentrate chemicals and microscale tests to detect toxicity - was used to monitor over time the bioavailability and potential toxicity of an oil spill. A simulated crude oil spill was initiated on an intertidal freshwater grass-wetland along the St. Lawrence River southwest of Quebec City, Quebec, Canada. Several phytoremediation treatments were investigated; to dissipate and ameliorate the spill, treatments included nutrient amendments with inorganic nitrogen sources (ammonium nitrate and sodium nitrate) and phosphate (super triple phosphate) with and without cut plants, with natural attenuation (no phytoremedial treatment) as a control. Sequestered oil residues were bioavailable in all oil-treated plots in Weeks 1 and 2. Interestingly, the samples were colored and fluoresced under ultraviolet light. In addition, microscale tests showed that sequestered residues were acutely toxic and genotoxic, as well as that they induced hepatic P450 enzymes. Analysis of these data suggested that polycyclic aromatic hydrocarbons were among the bioavailable residues sequestered. In addition, these findings suggested that the toxic bioavailable fractions of the oil spill and degradation products dissipated rapidly over time because after the second week the water column contained no oil or detectable degradation products in this riverine intertidal wetland. SPMD-TOX revealed no evidence of bioavailable oil products in Weeks 4, 6, 8, and 12. All phytoremediation efforts appeared to be ineffective in changing either the dissipation rate or the ability to ameliorate the oil toxicity. SPMD-TOX analysis of the water columns from these riverine experimental plots profiled the occurrence, dissipation, and influence of phytoremediation on the bioavailability and toxicity of oil products (parent or degradation products. ?? 2004 Wiley Periodicals, Inc.

  19. (222)Rn activity in groundwater of the St. Lawrence Lowlands, Quebec, eastern Canada: relation with local geology and health hazard.

    PubMed

    Pinti, Daniele L; Retailleau, Sophie; Barnetche, Diogo; Moreira, Floriane; Moritz, Anja M; Larocque, Marie; Gélinas, Yves; Lefebvre, René; Hélie, Jean-François; Valadez, Arisai

    2014-10-01

    One hundred ninety-eight groundwater wells were sampled to measure the (222)Rn activity in the region between Montreal and Quebec City, eastern Canada. The aim of this study was to relate the spatial distribution of (222)Rn activity to the geology and the hydrogeology of the study area and to estimate the potential health risks associated with (222)Rn in the most populated area of the Province of Quebec. Most of the groundwater samples show low (222)Rn activities with a median value of 8.6 Bq/L. Ninety percent of samples show (222)Rn activity lower than 100 Bq/L, the exposure limit in groundwater recommended by the World Health Organization. A few higher (222)Rn activities (up to 310 Bq/L) have been measured in wells from the Appalachian Mountains and from the magmatic intrusion of Mont-Saint-Hilaire, known for its high level of indoor radon. The spatial distribution of (222)Rn activity seems to be related mainly to lithology differences between U-richer metasediments of the Appalachian Mountains and magmatic intrusions and the carbonaceous silty shales of the St. Lawrence Platform. Radon is slightly enriched in sodium-chlorine waters that evolved at contact with clay-rich formations. (226)Ra, the parent element of (222)Rn could be easily adsorbed on clays, creating a favorable environment for the production and release of (222)Rn into groundwater. The contribution of groundwater radon to indoor radon or by ingestion is minimal except for specific areas near Mont-Saint-Hilaire or in the Appalachian Mountains where this contribution could reach 45% of the total radioactive annual dose. PMID:24973780

  20. Evaluation of liver histopathology and EROD activity in St. Lawrence lake sturgeon (Acipenser fulvescens) in comparison with a reference population

    SciTech Connect

    Rousseaux, C.G. ||; Branchaud, A.; Spear, P.A.

    1995-05-01

    In an attempt to evaluate the effects of contaminants on the lake sturgeon Acipenser fulvescens, fish were netted from two sites: Riviere des Prairies, confluent with the St. Lawrence River near Montreal, and a reference site on the upper reaches of the Ottawa River in the La Verendrye Park. Livers of fish collected from the Riviere des Prairies were difficult to homogenize, and they left behind strands of what appeared to be connective tissue. Suspecting hepatic fibrosis, the authors decided to evaluate the livers for histopathologic changes. Nineteen adult lake sturgeon (eleven male and eight female) were examined. Following fixation, routine processing, sectioning, and staining with hematoxylin and eosin, microscopic evaluation revealed the following: Sections taken from livers of fish from the Riviere des Prairies site showed excessive fat accumulation and often severe chronic-active cholangiohepatitis. Bile duct proliferation (p < 0.0001), periportal fibrosis (p < 0.0001), inflammation (p < 0.001), and fat accumulation (p < 0.05) were more pronounced in the fish from the Riviere des Prairies site. Melano-macrophage centers appeared to be both paler and gave the appearance of fewer numbers (p < 0.01). Livers from lake sturgeon taken from the reference site had a more normal appearance. The EROD levels were also significantly induced in these fish (reference 3.39 {+-} 0.57; Riviere des Prairies site 8.21 {+-} 0.87 pmol/mg protein/min; p < 0.0005). The EROD levels positively correlated with bile duct proliferation (r{sup 2} = 0.44; p = 0.001) and periportal fibrosis (r{sup 2} = 0.41; p = 0.002). Despite the statistical associations above, the authors cannot categorically state that contaminants are the sole cause of the lesions seen.

  1. Application of Acoustic and Optic Methods for Estimating Suspended-Solids Concentrations in the St. Lucie River Estuary, Florida

    USGS Publications Warehouse

    Patino, Eduardo; Byrne, Michael J.

    2004-01-01

    Acoustic and optic methods were applied to estimate suspended-solids concentrations in the St. Lucie River Estuary, southeastern Florida. Acoustic Doppler velocity meters were installed at the North Fork, Speedy Point, and Steele Point sites within the estuary. These sites provide varying flow, salinity, water-quality, and channel cross-sectional characteristics. The monitoring site at Steele Point was not used in the analyses because repeated instrument relocations (due to bridge construction) prevented a sufficient number of samples from being collected at the various locations. Acoustic and optic instruments were installed to collect water velocity, acoustic backscatter strength (ABS), and turbidity data that were used to assess the feasibility of estimating suspended-solids concentrations in the estuary. Other data collected at the monitoring sites include tidal stage, salinity, temperature, and periodic discharge measurements. Regression analyses were used to determine the relations of suspended-solids concentration to ABS and suspended-solids concentration to turbidity at the North Fork and Speedy Point sites. For samples used in regression analyses, measured suspended-solids concentrations at the North Fork and Speedy Point sites ranged from 3 to 37 milligrams per liter, and organic content ranged from 50 to 83 percent. Corresponding salinity for these samples ranged from 0.12 to 22.7 parts per thousand, and corresponding temperature ranged from 19.4 to 31.8 ?C. Relations determined using this technique are site specific and only describe suspended-solids concentrations at locations where data were collected. The suspended-solids concentration to ABS relation resulted in correlation coefficients of 0.78 and 0.63 at the North Fork and Speedy Point sites, respectively. The suspended-solids concentration to turbidity relation resulted in correlation coefficients of 0.73 and 0.89 at the North Fork and Speedy Point sites, respectively. The adequacy of the empirical equations seems to be limited by the number and distribution of suspended-solids samples collected throughout the expected concentration range at the North Fork and Speedy Point sites. Additionally, the ABS relations for both sites seem to overestimate at the low end and underestimate at the high end of the concentration range. Based on the sensitivity analysis, temperature had a greater effect than salinity on estimated suspended-solids concentrations. Temperature also appeared to affect ABS data, perhaps by changing the absorptive and reflective characteristics of the suspended material. Salinity and temperature had no observed effects on the turbidity relation at the North Fork and Speedy Point sites. Estimates of suspended-solids concentrations using ABS data were less 'erratic' than estimates using turbidity data. Combining ABS and turbidity data into one equation did not improve the accuracy of results, and therefore, was not considered.

  2. Glacially-megalineated limestone terrain of Anticosti Island, Gulf of St. Lawrence, Canada; onset zone of the Laurentian Channel Ice Stream

    NASA Astrophysics Data System (ADS)

    Eyles, Nick; Putkinen, Niko

    2014-03-01

    Anticosti is a large elongate island (240 km long, 60 km wide) in eastern Canada within the northern part of a deep water trough (Gulf of St. Lawrence) that terminates at the Atlantic continental shelf edge. The island's Pleistocene glaciological significance is that its long axis lay transverse to ice from the Quebec and Labrador sectors of the Laurentide Ice Sheet moving south from the relatively high-standing Canadian Shield. Recent glaciological reconstructions place a fast-flowing ice stream along the axis of the Gulf of St. Lawrence but supporting geologic evidence in terms of recognizing its hard-bedded onset zone and downstream streamlined soft bed is limited. Anticosti Island consists of gently southward-dipping limestone plains composed of Ordovician and Silurian limestones (Vaureal, Becscie and Jupiter formations) with north-facing escarpments transverse to regional ice flow. Glacial deposits are largely absent and limestone plains in the higher central plateau of the island retain a relict apparently ‘preglacial’ drainage system consisting of deeply-incised dendritic bedrock valleys. In contrast, the bedrock geomorphology of the lower lying western and eastern limestone plains of the island is strikingly different having been extensively modified by glacial erosion. Escarpments are glacially megalineated with a distinct ‘zig-zag’ planform reflecting northward-projecting bullet-shaped ‘noses’ (identified as rock drumlins) up to 2 km wide at their base and 4 km in length with rare megagrooved upper surfaces. Drumlins are separated by southward-closing, funnel-shaped ‘through valleys’ where former dendritic valleys have been extensively altered by the streaming of basal ice through gaps in the escarpments. Glacially-megalineated bedrock terrain such as on the western and eastern flanks of Anticosti Island is elsewhere associated with the hard-bedded onset zones of fast flowing ice streams and provides important ground truth for the postulated Laurentian Channel Ice Stream (LCIS) within the Gulf of St. Lawrence sector of the Laurentide Ice Sheet.

  3. 78 FR 40260 - International Joint Commission: Public Comment on a Proposal for Lake Ontario and St. Lawrence...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ...STATE [Public Notice 8369] International Joint Commission: Public Comment on a Proposal...Lawrence River Regulation The International Joint Commission (IJC) is inviting the public...the following addresses: International Joint Commission Secretary, U.S....

  4. Community-based participatory research projects and policy engagement to protect environmental health on St Lawrence Island, Alaska

    PubMed Central

    Miller, Pamela K.; Waghiyi, Viola; Welfinger-Smith, Gretchen; Byrne, Samuel Carter; Kava, Jane; Gologergen, Jesse; Eckstein, Lorraine; Scrudato, Ronald; Chiarenzelli, Jeff; Carpenter, David O.; Seguinot-Medina, Samarys

    2013-01-01

    Objectives This article synthesizes discussion of collaborative research results, interventions and policy engagement for St Lawrence Island (SLI), Alaska, during the years 2000–2012. Methods As part of on-going community-based participatory research (CBPR) studies on SLI, 5 discrete exposure-assessment projects were conducted: (a) a biomonitoring study of human blood serum; (b–d) 3 investigations of levels of contaminants in environmental media at an abandoned military site at Northeast Cape – using sediment cores and plants, semi-permeable membrane devices and blackfish, respectively; and (e) a study of traditional foods. Results Blood serum in residents of SLI showed elevated levels of polychlorinated biphenyls (PCBs) with higher levels among those exposed to the military site at Northeast Cape, an important traditional subsistence-use area. Environmental studies at the military site demonstrated that the site is a continuing source of PCBs to a major watershed, and that clean-up operations at the military site generated PCB-contaminated dust on plants in the region. Important traditional foods eaten by the people of SLI showed elevated concentrations of PCBs, which are primarily derived from the long-range transport of persistent pollutants that are transported by atmospheric and marine currents from more southerly latitudes to the north. Interventions An important task for all CBPR projects is to conduct intervention strategies as needed in response to research results. Because of the findings of the CBPR projects on SLI, the CBPR team and the people of the Island are actively engaging in interventions to ensure cleanup of the formerly used military sites; reform chemicals policy on a national level; and eliminate persistent pollutants internationally. The goal is to make the Island and other northern/Arctic communities safe for themselves and future generations. Conclusions As part of the CBPR projects conducted from 2000 to 2012, a series of exposure assessments demonstrate that the leaders of SLI have reason to be concerned about the health of people due to the presence of carcinogenic chemicals as measured in biomonitoring and environmental samples and important traditional foods. PMID:23977641

  5. CHINESE MITTEN CRABS (ERIOCHEIR SINENSIS) IN THE ST. LAWRENCE RIVER (CANADA): NEW RECORDS AND RISK OF INVASION

    EPA Science Inventory

    The Chinese mitten crab, Eriocheir sinensis, is an internationally renowned aquatic invader. Native to China and North/South Korea, this catadromous crab has successfully invaded several rivers and estuaries in eleven countries in Western Europe as well as the San Francisco Bay ...

  6. Trends of total cadmium, copper, and zinc in the zebra mussel (Dreissena polymorpha) along the upper reach of the St. Lawrence River: 1994-2005.

    PubMed

    Johns, Carolyn

    2012-09-01

    This study examines spatial and temporal variability of bioaccumulation of cadmium, copper, and zinc in tissues of zebra mussels in the upper reach of the St. Lawrence River which originates at the outflow of Lake Ontario. It was hypothesized that concentrations of these metals in mussel tissues would decline over time and decrease with increasing distance from the outlet of Lake Ontario as a result of on-going efforts to reduce contaminant discharges into the lake. Size of mussels was also evaluated as a factor influencing bioaccumulation. Mussels were collected annually in October from six sites from 1994 to 2005, including one site near a local industry. Individuals were grouped into five or more size classes per site in each year. Soft tissues were analyzed for total cadmium, copper and zinc. Concentrations of cadmium and copper in tissues varied significantly both spatially and temporally. Cadmium concentrations were elevated at most sites; copper concentrations were moderately elevated compared with other studies in the Lake Ontario basin and St. Lawrence River. Zinc showed the most uniformity in mussels possibly due to internal regulation and to low levels of environmental exposure. Animal size correlated with copper concentrations of tissues in approximately 30% of samples but infrequently for cadmium and zinc. Cadmium and copper levels were found to decline downstream over time. Inter-annual variability of metal concentrations in mussel tissues suggests utilization in long-term monitoring programs to discern significant trends. PMID:21922178

  7. Chlorinated hydrocarbons and mercury in sediments, red-winged blackbirds (Agelaius phoeniceus) and tree swallows (Tachycineta bicolor) from wetlands in the Great Lakes-St. Lawrence River basin

    SciTech Connect

    Bishop, C.A.; Koster, M.D.; Chek, A.A.; Hussell, D.J.T.; Jock, K.

    1995-03-01

    In 1991, the authors collected red-winged blackbird (Agelauis phoeniceus) eggs and tree swallow (Tachycineta bicolor) eggs and nestlings, and sediment samples from 2 wetland sites in the Great lakes and St. Lawrence River basin. They analyzed for chlorinated hydrocarbons and total mercury and found that biota contained contaminant concentrations which were one to two orders of magnitude above those in sediments. Maximum concentrations of contaminants were found in Akwesasne, St. Lawrence river (PCBs = 18,558.8 ng/g in red-winged blackbird eggs, oxychlordane = 58.8/g and mirex = 40.1 ng/g in tree swallow eggs); Mud Creek, Lake Erie and Cootes Paradise. Despite the migratory habits of red-winged blackbirds and tree swallows, agreement among biota and sediment in geographic variation of contaminant concentrations supports the use of these animals as biomonitors of persistent chemicals. Although chlorinated hydrocarbon concentrations in red-winged blackbird eggs were significantly correlated with sediment contamination, the local nature of the tree swallow chick diet suggests that nestlings would be the best indicator of local contaminant trends.

  8. Continuous analysis of dissolved gaseous mercury and mercury volatilization in the upper St. Lawrence River: exploring temporal relationships and UV attenuation.

    PubMed

    O'Driscoll, N J; Poissant, L; Canário, L; Ridal, J; Lean, D R S

    2007-08-01

    The formation and volatilization of dissolved gaseous mercury (DGM) is an important mechanism by which freshwaters may naturally reduce their mercury burden. Continuous analysis of surface water for diurnal trends in DGM concentration (ranging from 0 to 60.4 pg L(-1); n=613), mercury volatilization (ranging from 0.2 to 1.1 ng m(-2) h(-1); n=584), and a suite of physical and chemical measurements were performed during a 68 h period in the St. Lawrence River near Cornwall (Ontario, Canada) to examine the temporal relationships governing mercury volatilization. No lag-time was observed between net radiation and OGM concentrations (highest cross-correlation of 0.817), thus supporting previous research indicating faster photoreduction kinetics in rivers as compared to lakes. A significant lag-time (55-145 min; maximum correlation = 0.625) was observed between DGM formation and mercury volatilization, which is similar to surface water Eddy diffusion times of 42-132 min previously measured in the St. Lawrence River. A depth-integrated DGM model was developed using the diffuse integrated vertical attenuation coefficients for UVA and UVB (K(dI UVA) = 1.45 m(-1) K(dI UVB)= 3.20 m(-1)) Low attenuation of solar radiation was attributed to low concentrations of dissolved organic carbon (mean = 2.58 mg L(-1) and particulate organic carbon (mean = 0.58 mg L(-1) in the St. Lawrence River. The depth-integrated DGM model developed found that the top 0.3 m of the water column accounted for only 26% of the total depth-integrated DGM. A comparison with volatilization data indicated that a large portion (76% or 10.5 ng m(-2) of the maximum depth-integrated DGM (13.8 ng m(-2))is volatilized over a 24 h period. Therefore, at least 50% of all DGM volatilized was produced at depths below 0.3 m. These results highlight the importance of solar attenuation in regulating DGM formation with depth. The results also demonstrate both the fast formation of DGM in rivers and the importance of understanding DGM dynamics with depth as opposed to surface waters. PMID:17822100

  9. Changes in the northern Gulf of St. Lawrence ecosystem estimated by inverse modelling: Evidence of a fishery-induced regime shift?

    NASA Astrophysics Data System (ADS)

    Savenkoff, Claude; Castonguay, Martin; Chabot, Denis; Hammill, Mike O.; Bourdages, Hugo; Morissette, Lyne

    2007-07-01

    Mass-balance models have been constructed using inverse methodology for the northern Gulf of St. Lawrence for the mid-1980s, the mid-1990s, and the early 2000s to describe ecosystem structure, trophic group interactions, and the effects of fishing and predation on the ecosystem for each time period. Our analyses indicate that the ecosystem structure shifted dramatically from one previously dominated by demersal (cod, redfish) and small-bodied forage (e.g., capelin, mackerel, herring, shrimp) species to one now dominated by small-bodied forage species. Overfishing removed a functional group in the late 1980s, large piscivorous fish (primarily cod and redfish), which has not recovered 14 years after the cessation of heavy fishing. This has left only marine mammals as top predators during the mid-1990s, and marine mammals and small Greenland halibut during the early 2000s. Predation by marine mammals on fish increased from the mid-1980s to the early 2000s while predation by large fish on fish decreased. Capelin and shrimp, the main prey in each period, showed an increase in biomass over the three periods. A switch in the main predators of capelin from cod to marine mammals occurred, while Greenland halibut progressively replaced cod as shrimp predators. Overfishing influenced community structure directly through preferential removal of larger-bodied fishes and indirectly through predation release because larger-bodied fishes exerted top-down control upon other community species or competed with other species for the same prey. Our modelling estimates showed that a change in predation structure or flows at the top of the trophic system led to changes in predation at all lower trophic levels in the northern Gulf of St. Lawrence. These changes represent a case of fishery-induced regime shift.

  10. AFS Estuaries Section Newsletter Newsletter Editor Lee Benaka

    E-print Network

    Gopalakrishnan, K.

    1 AFS Estuaries Section Newsletter July 2014 Newsletter Editor ­ Lee Benaka NOAA, NMFS, F/ST4 1315--Secretary http://www.fisheriessociety.org/estuaries/ http://www.facebook.com/EstuariesSectionAFS PRESIDENT'S MESSAGE Happy Summer, Estuaries Section members! Warm weather has finally arrived on Cape Cod, and I took

  11. Speciation and transformation of phosphorus and its mixing behavior in the Bay of St. Louis estuary in the northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Lin, Peng; Chen, Min; Guo, Laodong

    2012-06-01

    Water samples were collected for measurements of dissolved, colloidal, and particulate inorganic and organic phosphorus (P) from the Bay of St. Louis estuary in the northern Gulf of Mexico during August 2008 and October 2009. Laboratory mixing experiments were also carried out using end-member river water and seawater to examine key processes and mechanisms controlling the behavior of P during estuarine mixing. Dissolved organic P (DOP) was the dominant species in the total dissolved P (TDP) pool in both lower (S < 10) and higher salinity (S > 25) regions, while dissolved inorganic P (DIP) predominated in mid-salinity regions (S of 10˜20) comprising up to 75% of the TDP. Both DIP and DOP behaved non-conservatively during estuarine mixing showing dramatic changes and transformation between different P species. The total particulate phosphorus (TPP) accounted for up to 85% of total phosphorus (TP = TDP + TPP) in the low-salinity areas but fell to about 38% in higher salinity regions. The quasi-negative correlation between TDP and TPP and the similarity in mixing behavior between field observations and laboratory experiments supported our hypothesis that physicochemical processes, such as dynamic repartitioning between water and particles or adsorption/desorption, are the predominant mechanisms controlling the biogeochemical cycling of P species in the Bay of St. Louis. River export fluxes of DIP could be significantly underestimated without the quantification of particulate P species, especially in more pristine river basins. The value of the distribution coefficient (in terms of logKd) ranged from 4.4 to 5.6 and decreased with increasing suspended particulate matter concentration and salinity, indicating that P is highly particle reactive and the presence of colloidal P may play an important role in the cycling of P in estuarine environments. Colloidal inorganic P (CIP) and colloidal organic P (COP), as quantified by an ultrafiltration permeation model, comprised 0-62% of the DIP and 34-93% of the DOP with the highest values in the river mouth area, suggesting a river source for colloidal P. The % CIP dropped to below the detection limit as salinity increased, whereas % COP first decreased but increased again with increasing salinity, reflecting different sources for CIP and COP in the lower estuary. The DOC/DOP ratio decreased rapidly with increasing salinity indicating a diagenetically older dissolved organic matter pool from the river and a dynamic change in sources and chemical speciation of P in the estuary.

  12. Putting oxygen and temperature thresholds of marine animals in context of environmental change in coastal seas: a regional perspective for the Scotian Shelf and Gulf of St. Lawrence

    NASA Astrophysics Data System (ADS)

    Brennan, Catherine E.; Blanchard, Hannah; Fennel, Katja

    2014-05-01

    We surveyed the literature in order to compile reported oxygen, temperature, salinity and depth preferences and thresholds of important marine species found in the Gulf of St. Lawrence and the Scotian Shelf regions of the northwest North Atlantic. We determined species importance based on the existence of a commercial fishery, a threatened or at risk status, or by meeting the following criteria: bycatch, baitfish, invasive, vagrant, important for ecosystem energy transfer, and predators and prey of the above species. Using the dataset compiled for the 53 regional fishes and macroinvertebrates, we rank species (including for different lifestages) by their maximum thermal limit, as well as by the lowest oxygen concentration tolerated before negative impacts (e.g. physiological stress), 50% mortality or 100% mortality are experienced. Additionally, we compare these thresholds to observed marine deoxygenation trends at multiple sites, and observed surface warming trends. This results in an assessment of which regional species are most vulnerable to future warming and oxygen depletion, and a first-order estimate of the consequences of thermal and oxygen stress on a highly productive marine shelf. If regional multi-decadal oxygen and temperature trends continue through the 21st century, many species will lose favorable oxygen conditions, experience oxygen-stress, or disappear due to insufficient oxygen. Future warming can additionally displace vulnerable species, though we note that large natural variability in environmental conditions may amplify or dampen the effects of anthropogenic surface warming trends. This dataset may be combined with regional ocean model predictions to map future species distributions.

  13. Export of biogenic carbon and structure and dynamics of the pelagic food web in the Gulf of St. Lawrence Part 1. Seasonal variations1

    NASA Astrophysics Data System (ADS)

    Savenkoff, C.; Vézina, A. F.; Roy, S.; Klein, B.; Lovejoy, C.; Therriault, J.-C.; Legendre, L.; Rivkin, R.; Bérubé, C.; Tremblay, J.-E.; Silverberg, N.

    2000-04-01

    The seasonal changes in photosynthetic production, respiration, sinking flux of organic carbon, and food web structure are described in the Gulf of St. Lawrence over a two-year period during the Canadian Joint Global Ocean Flux Study (JGOFS) program. The results show contrasts in net metabolism between periods of low (winter and spring) and high (summer and fall) vertical stability. The winter-spring period was associated with an autotrophic pelagic food web: predominance of large phytoplankton cells, large zooplankton, and high herbivorous potential transfers towards the zooplankton. The stratified summer-fall period was associated with a heterotrophic food web: dominance of small phytoplankton cells, replacement of the size class occupied by large phytoplankton with large heterotrophic dinoflagellates and ciliates, smaller zooplankton, and dominance of omnivorous transfers towards the zooplankton. Despite differences in algal size and composition as well as in size structure of the trophic compartments between winter-spring and summer-fall, the particulate organic carbon fluxes observed at 50 m depth was quantitatively similar during these two periods. Even though winter photosynthetic production was relatively low, the high chlorophyll a concentration, the size structure of the trophic compartments, and the high contribution of large phytoplankton cells (mainly diatoms) to biological activity were similar to those observed during the spring and could explain the high heterotrophic biomass observed during winter.

  14. Evaluation of a new Gulf of St. Lawrence coupled environmental prediction system based on the GEM atmospheric model and on the NEMO-CICE ocean-ice model

    NASA Astrophysics Data System (ADS)

    Pellerin, Pierre; Roy, François; Dick, Sarah; Smith, Greg; Dupont, Fred; Pilon, Mark; Senneville, Simon; Chanut, Jerome

    2015-04-01

    The Canadian operational Gulf of St. Lawrence (GSL) coupled environmental forecast system has been updated with a new ocean-ice component (NEMO-CICE) and coupling methodology. The use of NEMO-CICE will facilitate future advances toward an increase in resolution and the introduction of new scientific developments. Indeed NEMO and CICE are supported by a large scientific community and are based on more efficient computing technologies than the current system. An ensemble of hindcasts over previous years demonstrate that recent developments in the NEMO-CICE model make it possible to meet the high quality standards of the ocean model by Saucier et al. (2009) used in the previous operational system in terms of the tides, circulation and water mass properties. We present results from these hindcasts as well as from an experimental run for the winter of 2014 and compare them with the operational system. The experimental run includes a pseudo-analysis cycle producing daily initial ice-ocean conditions and their subsequent coupled atmosphere-ice-ocean 48 hr forecasts. We first examine extreme weather event cases, and then present results from a subjective evaluation as well as objective skill scores for SST analyses and for ice, surface air temperature and wind forecasts. The importance of the two-way coupling will also be assessed.

  15. Detection of viral hemorrhagic septicemia in round gobies in New York State (USA) waters of Lake Ontario and the St. Lawrence River

    USGS Publications Warehouse

    Groocock, G.H.; Getchell, R.G.; Wooster, G.A.; Britt, K.L.; Batts, W.N.; Winton, J.R.; Casey, R.N.; Casey, J.W.; Bowser, P.R.

    2007-01-01

    In May 2006 a large mortality of several thousand round gobies Neogobius melanostomus (Pallas, 1814) occurred in New York waters of the St. Lawrence River and Lake Ontario. Necropsies of sampled fish from these areas showed pallor of the liver and gills, and hemorrhagic areas in many organs. Histopathologic examination of affected tissues revealed areas of necrosis and hemorrhage. Inoculations of fathead minnow Pimephales promelas (Rafinesque, 1820) cell cultures with dilutions of tissue samples from the necropsied gobies produced a cytopathic effect within 5 d post-inoculation. Samples of cell culture supernatant were tested using RT-PCR and confirmed the presence of viral hemorrhagic septicemia virus (VHSV). Sequence analysis of the VHSV isolate resulted in its assignment to the type-IVb subgroup. The detection of VHSV in a relatively recent invasive fish species in the Great Lakes and the potential impact of VHSV on the ecology and economy of the area will require further investigation and careful management considerations. ?? Inter-Research 2007.

  16. St

    Cancer.gov

    St. Joseph Hospital Cancer Institute Physician Conditions of Participation A. PREAMBLE The vision of St. Joseph Hospital Cancer Institute is to attain the highest level of clinical excellence while providing an exceptional patient

  17. Annual dissolved nitrite plus nitrate and total phosphorous loads for the Susquehanna, St. Lawrence, Mississippi-Atchafalaya, and Columbia River basins, 1968-2004

    USGS Publications Warehouse

    Aulenbach, Brent T.

    2006-01-01

    Annual stream-water loads were calculated near the outlet of four of the larger river basins (Susquehanna, St. Lawrence, Mississippi-Atchafalaya, and Columbia) in the United States for dissolved nitrite plus nitrate (NO2 + NO3) and total phosphorus using LOADEST load estimation software. Loads were estimated for the period 1968-2004; although loads estimated for individual river basins and chemical constituent combinations typically were for shorter time periods due to limitations in data availability. Stream discharge and water-quality data for load estimates were obtained from the U.S. Geological Survey (USGS) with additional stream discharge data for the Mississippi-Atchafalaya River Basin from the U.S. Army Corps of Engineers. The loads were estimated to support national assessments of changes in stream nutrient loads that are periodically conducted by Federal agencies (for example, U.S. Environmental Protection Agency) and other water- and land-resource organizations. Data, methods, and results of load estimates are summarized herein; including World Wide Web links to electronic ASCII text files containing the raw data. The load estimates are compared to dissolved NO2 + NO3 loads for three of the large river basins from 1971 to 1998 that the USGS provided during 2001 to The H. John Heinz III Center for Science, Economics and the Environment (The Heinz Center) for a report The Heinz Center published during 2002. Differences in the load estimates are the result of using the most up-to-date monitoring data since the 2001 analysis, differences in how concentrations less than the reporting limit were handled by the load estimation models, and some errors and exclusions in the 2001 analysis datasets (which resulted in some inaccurate load estimates).

  18. Methane baseline concentrations and sources in shallow aquifers from the shale gas-prone region of the St. Lawrence lowlands (Quebec, Canada).

    PubMed

    Moritz, Anja; Hélie, Jean-Francois; Pinti, Daniele L; Larocque, Marie; Barnetche, Diogo; Retailleau, Sophie; Lefebvre, René; Gélinas, Yves

    2015-04-01

    Hydraulic fracturing is becoming an important technique worldwide to recover hydrocarbons from unconventional sources such as shale gas. In Quebec (Canada), the Utica Shale has been identified as having unconventional gas production potential. However, there has been a moratorium on shale gas exploration since 2010. The work reported here was aimed at defining baseline concentrations of methane in shallow aquifers of the St. Lawrence Lowlands and its sources using ?(13)C methane signatures. Since this study was performed prior to large-scale fracturing activities, it provides background data prior to the eventual exploitation of shale gas through hydraulic fracturing. Groundwater was sampled from private (n = 81), municipal (n = 34), and observation (n = 15) wells between August 2012 and May 2013. Methane was detected in 80% of the wells with an average concentration of 3.8 ± 8.8 mg/L, and a range of <0.0006 to 45.9 mg/L. Methane concentrations were linked to groundwater chemistry and distance to the major faults in the studied area. The methane ?(1)(3)C signature of 19 samples was > -50‰, indicating a potential thermogenic source. Localized areas of high methane concentrations from predominantly biogenic sources were found throughout the study area. In several samples, mixing, migration, and oxidation processes likely affected the chemical and isotopic composition of the gases, making it difficult to pinpoint their origin. Energy companies should respect a safe distance from major natural faults in the bedrock when planning the localization of hydraulic fracturation activities to minimize the risk of contaminating the surrounding groundwater since natural faults are likely to be a preferential migration pathway for methane. PMID:25751654

  19. Influence of late-summer storms on the horizontal variability of phytoplankton pigment determined by coastal zone color scanner images in the Gulf of St. Lawrence, Canada

    NASA Astrophysics Data System (ADS)

    Fuentes-Yaco, Cesar; Vezina, Alain F.; Gosselin, Michel; Gratton, Yves; Larouche, Pierre

    1997-02-01

    The western gulf of St. LAwrence (GSL) is characterized by high, persistent phytoplankton production and functions as the principal supplier of phytoplankton biomass for the central and eastern Gulf. The main objective of this study was to report on the evolution of a wind-induced phytoplankton bloom in this region. We used Coastal Zone Color Scanner images taken on 20, 22, 28, and 30 August 1980 to calculate phytoplankton pigment concentration, sea surface temperature and water reflectance fields. We coupled the satellite information with storm track, wind, air temperature, and bright sunshine data. A strong storm blew over the Gulf between 15 and 17 August, triggering upwelling and mixing processes that presumably made high nutrient concentrations available in the euphotic layer. High atmospheric pressure and southwesterly winds between 18 and 25 August allowed air and water temperatures to rise, stabilizing the water column and stimulating phytoplankton growth. A northern storm between 25 and 27 August associated with clear weather and low temperatures between 28 and 30 August, coinciding with the bloom decline. Water-normalized reflectance values suggested that the estuarine region was characterized by diatoms, the western-central GSL by a mixed composition of diatoms/small flagellates/coccolithophorids, and the eastern-central region by coccolithophorids and small flagellates. These blooms may be critical for fish recruitment. Cooling and warming of the water column by meteorological events seem to be intermittent but frequency at this time of year. The resulting nutrient input may support phytoplankton blooms of intensities similar to or higher than those recorded during spring in the western region of the Gulf.

  20. Detection and quantitation of benzo(a)pyrene-DNA adducts in brain and liver tissues of Beluga whales (Delphinapterus leucas) from the St. Lawrence and Mackenzie Estuaries

    SciTech Connect

    Shugart, L.R.

    1988-01-01

    It should be noted that there are few analytical techniques available for the detection and quantitation of chemical adducts in the DNA of living organisms. The reasons for this are: the analytical technique often has to accommodate the unique chemical and/or physical properties of the individual chemical or its metabolite; the percentage of total chemical that becomes most of the parent compound is usually detoxified and excreted; not all adducts that form between the genotoxic agent and DNA are stable or are involved in the development of subsequent deleterious events in the organism; and the amount of DNA available for analysis is often quite limited. 16 refs., 1 tab.

  1. The Betsiamites-Colombier slides along the St. Lawrence Estuary: linking a 7250 years BP submarine slide to a 1663 coastal landslide

    E-print Network

    the largest documented historic landslides in Canada. The presence of submarine scars, left by the early with subaerial and submarine landslide scars. The largest scars are identified in the vicinity of the Betsiamites submarine slide to a 1663 coastal landslide Locat, Jacques Université Laval, Département de géologie et

  2. Marine geology of the St. Lawrence Estuary This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-print Network

    of submarine canyons and channels to transfer sediments from the coast to the deeper marine environment of large submarine landslides during the Holocene, changes in sedimentation rates and the significant role

  3. PBDEs and PCBs in the liver of the St Lawrence Estuary beluga (Delphinapterus leucas): a comparison of levels and temporal trends with the blubber.

    PubMed

    Raach, Meriem; Lebeuf, Michel; Pelletier, Emilien

    2011-03-01

    Due to their lipophilic properties, persistent organic pollutants (POPs) are commonly assessed using the blubber of marine mammals. However, these chemicals are also accumulating in other tissues including the liver. Some pollutants, namely perfluorinated alkyl acids, are found predominately in the liver and blood of marine mammals, and thus monitored in those tissues. This raises the question whether any tissue would represent an identical trend of POPs in the SLE beluga. The current study reports the first temporal trends of PBDEs and PCBs in the liver of 65 SLE belugas. Neither ??PBDEs nor major individual PBDE-homolog group concentrations showed significant trends between 1993 and 2007. Also, ???PCBs did not change over years, although, tetra-, penta- and hepta-PCB decreased by 7.1, 6.8 and 8.5%, respectively, in males, whereas tetra-, penta- and octa-PCBs declined by 11, 12 and 12.9%, respectively, in females. In order to compare the distribution of POPs between liver and blubber, a lipid normalised concentration ratio R (blubber/liver) for PBDEs and PCBs was calculated for each individual beluga. For all PBDE and several PCB homolog groups, mean R values were not statistically different from unity indicating that the partitioning of these POPs is governed by the tissue lipid-content. Temporal trends of R ratios of PBDEs and PCBs were also examined. There were generally no significant temporal trends except for PBDEs in males where R increased in average by 12.7 ± 2.9% yearly. The stratification of the blubber into a metabolically active (inner) and less active layers (outer blubber) may result in a slower response time of the blubber (full depth) than the liver to the recent change of contamination in the environment and explain the time trend differences between both tissues. This study suggests that the liver is more representative of recent exposure to lipophilic contaminants. PMID:21270998

  4. Fault stability and CO2 storage in the Early Paleozoic sedimentary basin of the St. Lawrence Lowlands (Quebec, Canada): insight from coupled reservoir-geomechanical modeling

    NASA Astrophysics Data System (ADS)

    Konstantinovskaya, E.; Rutqvist, J.; Malo, M.

    2013-12-01

    A coupled reservoir-geomechanical (TOUGH-FLAC) modeling is applied to evaluate the potential shear failure along pre-existing high-angle normal faults and tensile failure in the caprock units (Utica Shale and Lorraine Group) associated with CO2 injection into the sandstone reservoir (Covey Hill Formation) of the Early Paleozoic sedimentary basin in the St. Lawrence Lowlands (Quebec, Canada). Field and subsurface data are used to estimate sealing properties of the faults. The spatial variations in fluid pressure, effective minimum horizontal stress and shear strain are calculated for different injection rates using a simplified 2D geological model of the Becancour area between Montreal and Quebec City. The simulation results show that the likelihood of reactivating two reservoir-bounding faults (Yamaska and Champlain Faults) strongly depends on reservoir pressure at the faults, which in turn depends on injection rate, hydrological properties of aquifers and the distance between the faults and the injection well. The Yamaska Fault, which is located closer (1.5 km) to the injection zone is easier reactivated than the more distant (4.4 km) Champlain Fault. In addition, fault permeability affects the timing, localization, rate and length of fault shear slip. If the fault is sealing, shear slip occurs later in time and it is localized along the fault segment (230 m) below the caprock units. If the fault is permeable, the fault reactivation starts earlier and shear slip is nucleated along the fault segment (50 m) in the caprock units subsequently progressing up to the surface. Sealing fault behaviour causes asymmetric fluid pressure build-up and lateral migration of CO2 plume away from the closer-to-injection Yamaska fault that reduces the overall risk of CO2 leakage along faults. The fluid-pressure induced tensile fracturing postdates shear failure along faults; it occurs only under extremely high reservoir pressure as a result of high injection rates, with fracturing being localized below the caprock units, which remain intact preventing upward CO2 migration. Fig. 1. Changes in effective shear strain occurred around the injection zone and along the Yamaska Fault during subsequent steps of experimental run, low injection rate, sealing fault behaviour. Fault slip occurs after 22.5 years of continued injection.

  5. Relationships among total recoverable and reactive metals and metalloid in St. Lawrence River sediment: bioaccumulation by chironomids and implications for ecological risk assessment.

    PubMed

    Desrosiers, Mélanie; Gagnon, Christian; Masson, Stéphane; Martel, Louis; Babut, Marc P

    2008-01-15

    The availability and bioaccumulation of metals and metalloids, and the geochemical interactions among them, are essential to developing an ecological risk assessment (ERA) framework and determining threshold concentrations for these elements. The purpose of this study was to explore the relationships among total recoverable and reactive metals and metalloid in sediment and their bioaccumulation by chironomids. In the fall of 2004 and 2005, 58 stations located in the three fluvial lakes of the St. Lawrence River and its largest harbour area in Montreal, Canada, were sampled. Nine total recoverable and reactive metals (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and one metalloid (As) were measured in whole sediment using two extraction methods: HCl/HNO(3) and HCl 1N, respectively. The bioaccumulation of six metals (Cd, Cr, Cu, Ni, Pb and Zn) and As by chironomids was evaluated in a subset of 22 stations. Strong collinearities were observed between some total recoverable or reactive metal concentrations in sediment; two principal clusters, including collinear metals, were obtained. The first one included metals of mainly geological origin (Al, Cr, Fe, Mn, Ni), while the second one included As, Cd, Cu, Pb and Zn, which likely derive mainly from point sources of anthropogenic contamination. Each element also showed strong collinearity between their total recoverable and reactive forms (0.65< or =r < or =0.97). We can conclude that both chemical forms are equivalent for use in statistical models needed to explain biological responses and also in screening risk assessment. However, these relationships are not always proportional. Lower availability percentages were observed for Cd, Cu and Zn in the highly mixed-contaminated area of the Montreal Harbour, even though concentrations in sediment were higher. We observed a significant correlation (0.50< or =r < or =0.56) between concentrations in chironomids and concentrations of both total recoverable and reactive Cr and Pb in sediment. Arsenic was an exception, with accumulation by chironomids being highly related to reactive sediment concentrations. Finally, we observed variable influences of explanatory factors (e.g. sediment grain size, Al, Fe, Mn, S, TOC), depending on which metal or metalloid was being predicted in chironomids. In this context, it is difficult to choose a universal predictive method to explain the bioaccumulation of specific metals, and more research is still needed into normalization procedures that consider a combination of explanatory factors. PMID:17900660

  6. Lawrence Residence 

    E-print Network

    Raiford Stripling Associates, Inc.; Stripling, Raiford L.

    1962-01-01

    .................................................................26 VI ACKNOWLEDGEMENTS I would like to the my advisor, Dr. Jennifer Pollack, and my committee members, Drs. Paul Montagna and Lee Smee for their help and guidance in completing this thesis. I would also like to thank the Coastal... General Land Grant, and NOAA for their generous contributions to this thesis. To everyone at the Texas A&M AgriLife Mariculture Research Lab, especially Dr. Addison Lawrence, Patty Beasley, Roger Anderson, Woody Lawson, Terrence Ussery and Jessica...

  7. Estuary Habitat Restoration INTRODUCTION

    E-print Network

    US Army Corps of Engineers

    1 Estuary Habitat Restoration STRATEGY 2012 INTRODUCTION The Estuary Restoration Act of 2000 (ERA agencies to maximize benefits derived from estuary habitat restoration projects and address the pressures facing our nation's estuaries. The ERA established an inter-agency Estuary Habitat Restoration Council

  8. Maturity, size at age and predator-prey relationships of winter skate Leucoraja ocellata in the southern Gulf of St Lawrence: potentially an undescribed endemic facing extirpation.

    PubMed

    Kelly, J T; Hanson, J M

    2013-03-01

    The goals of this study were to document the size and age structure, size at maturity, ovarian fecundity and diet of the endangered population of winter skate Leucoraja ocellata that resides in the southern Gulf of St Lawrence (SGSL). The maximum size observed for SGSL L. ocellata was 68?cm total length (LT ) but >99% of animals caught were <60?cm LT . Fifty per cent of male and female L. ocellata were fully mature at 40 and 42?cm LT , respectively, age c. 5?years. The oldest individual caught was age 11?years, but 98% of the 561 individuals examined were ?age 8?years, indicating a short reproductive life span. Ovarian fecundity was low; no more than 29 ova >10 mm diameter were ever observed. At 40?cm LT , the diet changed from one dominated by shrimp Crangon septemspinosa and gammarid amphipods to one dominated by fishes (mainly sand lance Ammodytes spp. and rainbow smelt Osmerus mordax) and Atlantic rock crab Cancer irroratus. Sufficient differences were observed between SGSL L. ocellata and other populations in their size-at-maturity pattern and maximum size to propose the taxonomic re-evaluation of the population. PMID:23464554

  9. ERNESTORLANDO LAWRENCE BERKELEY NATIONALLABORATORY

    E-print Network

    Korneev, Valeri A.

    . Department of Commerce 5285 Port Royal Road, Springfield, VA 22161 Ernest Orlando Lawrence Berkeley National-domainsolutionsfor nonlinear elastic 1-Dplane wave propagation Valeri A Korneev Earth Sciences Division Ernest OrlandoLawrenceERNESTORLANDO LAWRENCE BERKELEY NATIONALLABORATORY TimeDomain Solutions for Nodhear Elastic 1=D

  10. In vitro biotransformation of decabromodiphenyl ether (BDE-209) and Dechlorane Plus flame retardants: a case study of ring-billed gull breeding in a pollution hotspot in the St. Lawrence River, Canada.

    PubMed

    Chabot-Giguère, Bernice; Letcher, Robert J; Verreault, Jonathan

    2013-05-01

    Decabromodiphenyl ether (deca-BDE) mixture (~97% of BDE-209) is now facing usage restrictions worldwide, which is leading to increased utilization of a series of alternative, replacement flame retardant (FR) products. Among these, Dechlorane Plus (DP) is receiving growing attention as this FR is increasingly being detected in wildlife samples, including birds from North America, Europe and Asia. Recent survey conducted in a known FR hotspot in the St. Lawrence River basin near Montreal (QC, Canada) revealed unexpectedly high detection frequencies and concentrations of BDE-209 and DP isomers (syn- and anti-DP) in the liver of breeding ring-billed gulls (Larus delawarensis) (RBGUs). Despite the global distribution of these current-use FRs, there is to our knowledge no study that has addressed the in vitro biotransformation of BDE-209 and DP isomers in birds. This study aimed at understanding the in vitro metabolism of BDE-209 and syn- and anti-DP using liver microsomes of Montreal-breeding RBGUs. Although BDE-15 (positive assay control) was consistently and positively depleted over the 90-min time frame of the in vitro assay, no depletion was observed for BDE-209 and DP isomers. These results suggest that CYP isoenzyme-mediated reductive dehalogenation of BDE-209 and DP is not likely to be a substantial metabolic pathway in RBGUs. However, investigations on deiodinases (expression, activity) should be considered in future studies as these enzymes have been suggested to be involved in the sequential debromination of BDE-209 in fish and human studies. High levels of BDE-209 determined in liver of RBGUs that strongly correlated with those of known or suggested BDE-209 debromination products (hepta- through nona-BDEs) may thus be indicative of concomitant dietary (e.g., fish consumption) and environmental exposure in the greater Montreal area, combined with poor or lack of metabolic capability toward these FRs. PMID:23542572

  11. Introduction to Estuaries

    EPA Science Inventory

    Estuaries, although minor geographical features at the global scale, have major importance for society and the world’s economies. This chapter introduces estuaries by presenting an overview of definitions, origins, physical, chemical and ecological attributes, and the interaction...

  12. Distribution, abundance, and range of the round goby, Apollina melanostoma, in the Duluth-Superior Harbor and St. Louis River estuary, 1998-2004

    USGS Publications Warehouse

    Bergstrom, M.A.; Evrard, L.M.; Mensinger, A.F.

    2008-01-01

    Round gobies were first discovered in the Duluth-Superior Harbor, Lake Superior, in 1995. Anecdotal sightings by anglers and others suggested that the infestation was growing and expanding; however, direct evidence of the distribution and expansion rate in the harbor was largely unknown. Distribution and range of the round goby, Apollonia melanostoma, (formerly Neogobius melanostomus) was assessed using bottom trawl sampling throughout the Duluth-Superior Harbor, and portions of the lower St. Louis River from 1998 to 2004. Previous to 1998, round gobies only were reported to occupy the harbor between the two shipping entries (river kilometer 1 to 7). By 2004, they expanded throughout the harbor and upstream to river kilometer 13, but remained absent in western Lake Superior. The number of round gobies captured per 5 minutes of trawling (catch per unit effort, CPUE) increased from less than 1 fish in 1998 to an average 5.4 ?? 1.2 SE fish in 2004, indicating a large increase in the population. The median yearly fish total length varied from 56.0 to 81.5 mm and wet weight varied from 2.3 to 7.0 g. As nest guarding male round gobies were located in rocky habitats inaccessible to trawling, the initial years were dominated by female round gobies with a 16:1 female to male ratio, but by 2002 the maximum ratio was 2:1. The ratio change may be indicative of the increasing population forcing males from their preferred rocky habitat onto open substrates that were more accessible to trawling.

  13. Eutrophication of the St. Lawrence Great Lakes

    USGS Publications Warehouse

    Beeton, Alfred M.

    1965-01-01

    Lakes Huron, Michigan, and Superior are classified as oligotrophic lakes on the basis of their biological, chemical, and physical characteristics. Lake Ontario, although rich in nutrients, is morphometrically oligotrophic or mesotrophic because of its large area of deep water. Lake Erie, the most productive of the lakes and the shallowest, is eutrophic. Several changes commonly associated with eutrophication in small lakes have been observed in the Great Lakes. These changes apparently reflect accelerated eutrophication in the Great Lakes due to man's activity. Chemical data compiled from a number of sources, dating as early as 1854, indicate a progressive increase in the concentrations of various major ions and total dissolved solids in all of the lakes except Lake Superior. The plankton has changed somewhat in Lake Michigan and the plankton, benthos, and fish populations of Lake Erie are greatly different today from those of the past. An extensive area of hypolimnetic water of Lake Erie has developed low dissolved oxygen concentrations in late summer within recent years.

  14. ERNEST ORLANDO LAWRENCE BERKELEYNATIONALLABORATORY

    E-print Network

    Korneev, Valeri A.

    LBNL-41914 ERNEST ORLANDO LAWRENCE BERKELEYNATIONALLABORATORY Nonlinear Interaction of Plane Port Royal Road, Springfield, VA 22161 Ernest Orlando Lawrence Berkeley National Laboratory is an equalInteractionof Plane Elastic Waves Valeri A Korneev, Kurt T Nihei and Larry RMyer Earth Sciences Division Ernest

  15. Linking Species Traits to the Abiotic Template of Flowing Waters: Contrasting Eco physiologies Underlie Displacement of Zebra Mussels by Quagga Mussels in a Large River-Estuary

    NASA Astrophysics Data System (ADS)

    Casper, A. F.

    2005-05-01

    The St. Lawrence River-Estuary was the gateway of entry for dreissenids to North America and holds some of the oldest populations. The St. Lawrence also has four distinct physical-chemical water masses (a regional scale abiotic template) that both species inhabit. Despite their ecological similarities, quagga mussels are supplanting zebra mussels in much of their shared range. In order to try to better understand the changing distributions of these two species we compared glycogen, shell mass and tissue biomass in each of the water masses. This comparative physiological combined with experimental approaches (estuarine salinity experiments and reciprocal transplants) showed that while quagga mussels should dominate in most habitats, that abiotic/bioenergetic constraints in two regions (the Ottawa River plume and the freshwater-marine transition zone) might prevent them from dominating these locations. These findings are an example of how the interaction of landscape scale abiotic heterogeneity and a species-specific physiology can have strong impacts of distribution of biota large rivers.

  16. Learning Lessons from Estuaries

    ERIC Educational Resources Information Center

    Schnittka, Christine

    2006-01-01

    There is something that draws all people to the sea and especially to the fertile estuaries that nuzzle up to its shores. An estuary serves as both a nursery and a grave for sea creatures. If life evolved from some primordial sea, it may well have been an estuary--a place where ocean and rivers meet and fresh and salty waters mingle in the…

  17. Negroes of Lawrence

    E-print Network

    Goodnight, Lizzie E.

    1903-01-01

    ScholarWorks | The University of Kansas Pre-1923 Dissertations and Theses Collection Negroes of Lawrence 1903 by Lizzie E. Goodnight This work was digitized by the Scholarly Communications program staff in the KU Libraries’ Center for Digital Scholarship...

  18. Estuary Data Mapper

    EPA Science Inventory

    The U.S. Environmental Protection Agency (US EPA) is developing e-Estuary, a decision-support system for coastal management. E-Estuary has three elements: an estuarine geo-referenced relational database, watershed GIS coverages, and tools to support decision-making. To facilita...

  19. Estuary Restoration Act Estuary Habitat Restoration Council

    E-print Network

    US Army Corps of Engineers

    densiflora) ("Spartina") as part of a regional eradication program. 3. Eelgrass Restoration in Puget Sound estuary restoration efforts and to contribute to the Puget Sound Partnership's Action Agenda recovery goal, 2013 1. Grassy Flats Estuarine Habitat Restoration Project, FL This project will cap anoxic, fine

  20. Metaproteomics of aquatic microbial communities in a deep and stratified estuary.

    PubMed

    Colatriano, David; Ramachandran, Arthi; Yergeau, Etienne; Maranger, Roxane; Gélinas, Yves; Walsh, David A

    2015-10-01

    Here we harnessed the power of metaproteomics to assess the metabolic diversity and function of stratified aquatic microbial communities in the deep and expansive Lower St. Lawrence Estuary, located in eastern Canada. Vertical profiling of the microbial communities through the stratified water column revealed differences in metabolic lifestyles and in carbon and nitrogen processing pathways. In productive surface waters, we identified heterotrophic populations involved in the processing of high and low molecular weight organic matter from both terrestrial (e.g. cellulose and xylose) and marine (e.g. organic compatible osmolytes) sources. In the less productive deep waters, chemosynthetic production coupled to nitrification by MG-I Thaumarchaeota and Nitrospina appeared to be a dominant metabolic strategy. Similar to other studies of the coastal ocean, we identified methanol oxidation proteins originating from the common OM43 marine clade. However, we also identified a novel lineage of methanol-oxidizers specifically in the particle-rich bottom (i.e. nepheloid) layer. Membrane transport proteins assigned to the uncultivated MG-II Euryarchaeota were also specifically detected in the nepheloid layer. In total, these results revealed strong vertical structure of microbial taxa and metabolic activities, as well as the presence of specific "nepheloid" taxa that may contribute significantly to coastal ocean nutrient cycling. PMID:26223443

  1. Aging and sediment characteristics of northern Gulf of Mexico estuaries

    SciTech Connect

    Isphording, W.C. ); Imsand, F.D. ); Flowers, G.C. )

    1989-09-01

    Eight major estuarine systems present along the northern margin of the Gulf of Mexico serve as primary depositional basins for all rivers draining into the gulf from central Louisiana eastward to the Florida peninsula. These estuaries consist of Apalachicola Bay, St. Andrews Bay, Choctawhatchee Bay, Pensacola Bay, Perdido Bay, Mobile Bay, Mississippi sound, and Lake Pontchartrainn. Because each receives sediment from a different river system (or systems), each estuary is characterized by sediments that are both physically and mineralogically distinct. Estuaries in the eastern Gulf, for example, possess a clay mineral suite dominated by kaolinite (derived from deeply weathered piedmont rocks), whereas those from the western Gulf are rich in smectite and mixed layer clays (reflecting a Western Interior or provenance from Paleozoic or older coastal plain sources). Similarly, weathering of rocks in the southern piedmont has provided eastern Gulf estuarine sediments with a suite of largely metamorphic rock-derived heavy minerals, whereas those in the western Gulf contain a mixed suite of both igneous- and metamorphic-derived minerals. Equally distinctive, however, are the textures of the bottom sediments themselves for each estuary when plotted on standard sand-silt-clay ternary diagrams. The relative percentages of these components are uniquely different for most of the estuaries and reflect both natural and anthropogenic conditions that exist in the watershed areas that drain into each estuary.

  2. DELAWARE ESTUARY PCB MODEL

    EPA Science Inventory

    The Delaware River Basin Commission recently completed the first phase of a program to develop and implement Total Maximum Daily Loads (TMDLs) for toxic pollutants for the Delaware Estuary. This complex body of water extends from the head of tide at Trenton, NJ (River Mile 133.2...

  3. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL-58252 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Rationale for Measuring Duct thereof, or The Regents of the University of California. Ernest Orlando Lawrence Berkeley National Division Ernest Orlando Lawrence Berkeley National Laboratory University of California Berkeley, California

  4. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 58752 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Laboratory Evaluation of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. 3 #12;Abstract A testing program was undertaken at Lawrence Berkeley National Laboratory and an electric utility

  5. Ernest Orlando Lawrence Berkeley National Laboratory

    E-print Network

    2004 ALS ACTIVITY REPORT Ernest Orlando Lawrence Berkeley National Laboratory University. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. CSO 10508 #12;2004 ALS ACTIVITY REPORT July 2005 Ernest Orlando Lawrence Berkeley National Laboratory University

  6. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL-254E ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY ALDEHYDE AND OTHER VOLATILE ORGANIC of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. #12;LBNL Environment Department Environmental Energy Technologies Division Lawrence Berkeley National Laboratory

  7. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 53484 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Heat Recovery in Building Envelopes Environment Department Lawrence Berkeley National Laboratory Berkeley, CA. 94720, USA ABSTRACT Infiltration

  8. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 54767 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Duct Tape Durability Testing M of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. Legal

  9. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 43382 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Evaluation of PEGIT Duct Connection of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. 2 #12

  10. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 52084 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Experimental Evaluation of Gas of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. 2 #12

  11. THREE-DIMENSIONAL MODELING OF COHESIVE SEDIMENT TRANSPORT IN A PARTIALLY STRATIFIED MICRO-TIDAL ESTUARY TO ASSESS EFFECTIVENESS OF SEDIMENT TRAPS

    EPA Science Inventory

    The three-dimensional (3D) finite difference model Environmental Fluid Dynamics Code (EFDC) was used to simulate the hydrodynamics and sediment transport in a partially stratified micro-tidal estuary. The estuary modeled consisted of a 16-km reach of the St. Johns River, Florida,...

  12. Ecology of estuaries

    SciTech Connect

    Kennish, M.J. )

    1992-01-01

    Ecology of Estuaries: Anthropogenic Effects represents the most definitive and comprehensive source of reference information available on the human impact on estuarine ecosystems. The book discusses both acute and insidious pollution problems plaguing these coastal ecotones. It also provides a detailed examination of the deleterious and pervasive effects of human activities on biotic communities and sensitive habitat areas in estuaries. Specific areas covered include organic loading, oil pollution, polynuclear aromatic hydrocarbons, chlorinated hydrocarbons, heavy metals, dredging and dredge-spoil disposal, radionuclides, as well as other contaminants and processes. The diverse components of these anthropogenic influences are assembled in an organized framework and presented in a clear and concise style that will facilitate their understanding.

  13. Ecology of estuaries

    SciTech Connect

    Kennish, M.J.

    1986-01-01

    This book is a summary of information available on estuarine ecology, that reviews concepts and problems of estuaries and assesses the value of these coastal systems. It investigates such topics as water circulation and mixing, trace elements, nutrients, organic matter, and sedimentary processes, with reviews on more than two decades of intense study. Chapters reflect contributions from a variety of interdisciplinary sciences including botany, chemistry, ecology, geology, physics, and zoology.

  14. Monitoring and Managing Water Quality in the San Francisco Estuary San Francisco Estuary Institute and the

    E-print Network

    Monitoring and Managing Water Quality in the San Francisco Estuary San Francisco Estuary Institute and the Regional Monitoring Program for Water Quality in the San Francisco Estuary #12;www.sfei.org #12;Contribution 517 Monitoring and Managing Water Quality in the San Francisco Estuary San Francisco Estuary

  15. Estuary Restoration Act of 2000 Title I of Estuaries and Clean Waters Act of 2000

    E-print Network

    US Army Corps of Engineers

    Estuary Restoration Act of 2000 Title I of Estuaries and Clean Waters Act of 2000 Public Law 106 of the Estuary Restoration Act, Title I of P.L. 106-457 (Act). The contents reflect the views of the Estuary). Background: The purposes of the Act are to promote the restoration of estuary habitat; develop a national

  16. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL-56292 LBNL 56292 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Efficacy of Intermittent Government or any agency thereof, or The Regents of the University of California. Ernest Orlando Lawrence

  17. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 57330 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY State-of-the-art in Residential of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. 3 #12

  18. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 54005 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Register Closing Effects on Forced Government or any agency thereof, or The Regents of the University of California. Ernest Orlando Lawrence

  19. Joseph S. Miller Lawrence S. Moss

    E-print Network

    Miller, Joseph S.

    Joseph S. Miller Lawrence S. Moss The Undecidability of Iterated Modal Relativization Abstract and Lawrence S. Moss also assume that none of the children can see their own foreheads and that all children

  20. Toward delisting of the water quality beneficial use impairment in the St. Louis River, MN: A monitoring approach

    EPA Science Inventory

    Water quality in the St. Louis River Estuary (SLRE), a great lakes area of concern (AOC), is improving. A significant leap forward followed the opening of the Western Lake Superior Sanitary District in 1978. However, desire for continued improvement throughout the estuary was the...

  1. LAWRENCE BERKELEY NATIONAL LABORATORY REPORT NO. LBNL-59202 ERNEST ORLANDO LAWRENCE

    E-print Network

    LAWRENCE BERKELEY NATIONAL LABORATORY REPORT NO. LBNL- 59202 ERNEST ORLANDO LAWRENCE BERKELEY of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. #12;LAWRENCE BERKELEY NATIONAL LABORATORY REPORT NO. LBNL- 59202 Air Tightness of US Homes: Model Development1

  2. Seasonal dissolved inorganic nitrogen and phosphorus budgets for two sub-tropical estuaries in south Florida, USA

    NASA Astrophysics Data System (ADS)

    Buzzelli, C.; Wan, Y.; Doering, P. H.; Boyer, J. N.

    2013-02-01

    Interactions among watershed nutrient loading, circulation, and biogeochemical cycling determine the capacity of estuaries to accommodate introduced nutrients. Baseline quantification of loading, flushing time, export, and internal processes is essential to understand responses of sub-tropical estuaries to variable climate and nutrient loading. The goal of this study was to develop seasonal dissolved inorganic nitrogen (DIN) and phosphorus (DIP) budgets for the two estuaries in south Florida, the Caloosahatchee River Estuary (CRE) and the St. Lucie Estuary (SLE), from 2002-2008 spanning various climatic conditions. The Land Ocean Interactions in the Coastal Zone (LOICZ) Biogeochemical Model was used to generate water, salt, and (DIN and DIP) budgets. The predicted increase in internal DIN production for the CRE vs. the SLE was associated with increased external DIN loading. Water column DIN concentrations decreased and stabilized in both estuaries as flushing time increased to > 10 d. The CRE demonstrated heterotrophy or balanced metabolism across all seasonal budgets. Although the SLE was also sensitive to DIN loading, system autotrophy and net ecosystem metabolism increased with DIP loading to this estuary. This included a huge DIP consumption and bloom of a cyanobacterium (Microcystis aeruginosa) following hurricane-induced discharge in 2005. Additionally, while denitrification offered a loss pathway for inorganic nitrogen in the CRE, this potential was not evident for the smaller and more anthropogenically altered St. Lucie Estuary. Disparities between total and inorganic loading ratios suggested that management actions should examine the role of dissolved organic nitrogen (DON) in attempts to reduce both nitrogen and phosphorus inputs to the SLE. Establishment of quantitative loading limits for anthropogenically impacted estuaries requires an understanding of the inter-seasonal and inter-annual relationships for both N and P, circulation and flushing, variability in plankton community composition, and the dynamics of DON.

  3. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL-62078 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Air Leakage of U.S. Homes: Model of the University of California or any other sponsor. Ernest Orlando Lawrence Berkeley National Laboratory of the ventilation used to control IAQ. The Lawrence Berkeley National Laboratory has been gathering residential air

  4. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL-63193 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Multizone Age-of-Air Analysis MAX H thereof, or The Regents of the University of California. Ernest Orlando Lawrence Berkeley National Energy Performance of Buildings Group Lawrence Berkeley National Laboratory1 ABSTRACT Age of air

  5. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 57225 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Duct Tape and Sealant Performance I of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. Legal, it is important to understand how duct tape works for its ostensible purpose--to seal ducts. At the Lawrence

  6. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 59620 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Ventilation Behavior and Household the accuracy or adequacy of this information in this report. Ernest Orlando Lawrence Berkeley National and the Lawrence Berkeley National Laboratory under the sponsorship of the California Air Resources Board

  7. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    McCalley, James D.

    LBNL-4143E ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Power and Frequency Control of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. #12;Power a subcontract administered by the Lawrence Berkeley National Laboratory, which is operated by the University

  8. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 42127 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Distribution System Leakage Impacts of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. 1 #12, ventilation. Iain S. Walker is a staff scientist at Lawrence Berkeley National Laboratory, Berkeley, CA

  9. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 54496 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Houses Need to Breathe...Right? M Government or any agency thereof, or The Regents of the University of California. Ernest Orlando Lawrence Environment Department Lawrence Berkeley National Laboratory One Cyclotron Road Berkeley, CA 94720 October

  10. Estuary Restoration Act of 2000 Title I of Estuaries and Clean Waters Act of 2000

    E-print Network

    US Army Corps of Engineers

    Estuary Restoration Act of 2000 Title I of Estuaries and Clean Waters Act of 2000 Public Law 106 of Section 108 of the Estuary Restoration Act, Title I of P.L. 106-457 (Act). This report covers the fiscal years 2004 through 2006 and reflects the views of the Estuary Habitat Restoration Council (Council

  11. Dissolved oxygen in two Oregon estuaries: The importance of the ocean-estuary connection

    EPA Science Inventory

    We examined the role of the ocean –estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

  12. Dissolved oxygen in two Oregon estuaries: Importance of the ocean-estuary connection

    EPA Science Inventory

    We examined the role of the ocean –estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

  13. Dissolved oxygen in two Oregon estuaries: Importance of the ocean-estuary connection - March 2011

    EPA Science Inventory

    We examined the role of the ocean–estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO w...

  14. Secure Remote Login Lawrence Brown

    E-print Network

    Brown, Lawrie

    for Computer Security Research University College, UNSW, Australian Defence Force Academy Canberra ACT 2600Secure Remote Login Lawrence Brown lpb@cs.adfa.oz.au Department of Computer Science Centre. Australia. Abstract In this paper I discuss some alternative approaches to providing security in remote

  15. PECONIC ESTUARY EELGRASS HABITAT CRITERIA STUDY

    EPA Science Inventory

    PECONIC ESTUARY EELGRASS HABITAT CRITERIA STUDY The main objective of this study is to develop criteria for eelgrass habitat establishment and persistence within the Peconic Estuary utilizing various environmental analyses. The Program evaluated water and sediment quality data to...

  16. Application of microwave radiometers for wetlands and estuaries monitoring

    SciTech Connect

    Shutko, A.; Haldin, A.; Novichikhin, E.

    1997-06-01

    This paper presents the examples of experimental data obtained with airborne microwave radiometers used for monitoring of wetlands and estuaries located in coastal environments. The international team of researchers has successfully worked in Russia, Ukraine and USA. The data presented relate to a period of time between 1990 and 1995. They have been collected in Odessa Region, Black Sea coast, Ukraine, in Regions of Pittsville and Winfield, Maryland, USA, and in Region of St. Marks, Florida, USA. The parameters discussed are a soil moisture, depth to a shallow water table, vegetation index, salinity of water surface.

  17. PECONIC ESTUARY STORMWATER ASSESSMENT AND PLANNING TOOL

    EPA Science Inventory

    PECONIC ESTUARY STORMWATER ASSESSMENT AND PLANNING TOOL Horsley & Witten, Inc. was contracted by the Peconic Estuary Program to create a Regional Stormwater Runoff Management Plan designed to mitigate loadings of fecal coliform bacteria and nitrogen to the Peconic Estuary. The pu...

  18. KNOW YOUR ESTUARY: THE WATER THROUGH TIME

    EPA Science Inventory

    This presentation will focus on historical changes in water quality in the Yaquina Estuary, Oregon, and factors which influence water quality within this estuary. Topics presented will include the importance of ocean conditions on water quality in the estuary; historical changes...

  19. Assessing the application of an airborne intensified multispectral video camera to measure chlorophyll a in three Florida estuaries

    SciTech Connect

    Dierberg, F.E.; Zaitzeff, J.

    1997-08-01

    After absolute and spectral calibration, an airborne intensified, multispectral video camera was field tested for water quality assessments over three Florida estuaries (Tampa Bay, Indian River Lagoon, and the St. Lucie River Estuary). Univariate regression analysis of upwelling spectral energy vs. ground-truthed uncorrected chlorophyll a (Chl a) for each estuary yielded lower coefficients of determination (R{sup 2}) with increasing concentrations of Gelbstoff within an estuary. More predictive relationships were established by adding true color as a second independent variable in a bivariate linear regression model. These regressions successfully explained most of the variation in upwelling light energy (R{sup 2}=0.94, 0.82 and 0.74 for the Tampa Bay, Indian River Lagoon, and St. Lucie estuaries, respectively). Ratioed wavelength bands within the 625-710 nm range produced the highest correlations with ground-truthed uncorrected Chl a, and were similar to those reported as being the most predictive for Chl a in Tennessee reservoirs. However, the ratioed wavebands producing the best predictive algorithms for Chl a differed among the three estuaries due to the effects of varying concentrations of Gelbstoff on upwelling spectral signatures, which precluded combining the data into a common data set for analysis.

  20. Ecology of estuaries: Anthropogenic effects

    SciTech Connect

    Kennish, M.J.

    1992-01-01

    Estuaries and near-shore oceanic water are subjected to a multitude of human wastes. The principal objective of this book is to examine anthropogenic effects on estuaries, and it focuses primarily on contaminants in coastal systems. Covered within various chapters are the following topics: waste disposal strategies; definition and classification of pollutants (including organic loading, oil pollution, polynuclear aromatic hydrocarbons; chlorinated hydrocarbons; heavy metals; radionuclides) biological impacts; waste management; impacts of power plants; dredging and spoil disposal; case studies, primarily Chesapeake Bay. The book serves as a text and as a reference.

  1. HIGHLAND AVE OVERHILL ST

    E-print Network

    Mohaghegh, Shahab

    FORREST AVE BAIRD ST REID ST WATERST BEECHURSTAVE USHWY119HWY119 CHESTNUTST HIGHST WALNUT ST COURT ST Boreman Hall North 652 North High Street WVU Storage & Surplus Center PRT Station Walnut St. RFL House HICKO RY ST SAYERS ST TR IPLETT ST TR IPPETT ST KENTST OAK ST WALNUT ST NEW BASEBALL PARK Monongahela

  2. DELAWARE ESTUARY A MANAGEMENT PLAN FOR THE DELAWARE ESTUARY

    EPA Science Inventory

    Wise conservation and management of the Delaware Estuary is arguably the most important cooperative environmental initiative ever jointly undertaken by the States of New Jersey, Pennsylvania, and Delaware. While much has been accomplished over the past few decades to improve wate...

  3. Food Webs in an Estuary.

    ERIC Educational Resources Information Center

    Dunne, Barbara B.

    The Maryland Marine Science Education Project has produced a series of mini-units in marine science education for the junior high/middle school classroom. This unit focuses on food chains in an estuary. Although the unit specifically treats the Chesapeake Bay, it may be adapted for use with similar estuarine systems. In addition, the unit may be…

  4. Simulated Sampling of Estuary Plankton

    ERIC Educational Resources Information Center

    Fortner, Rosanne W.; Jenkins, Deborah Bainer

    2009-01-01

    To find out about the microscopic life in the valuable estuary environment, it is usually necessary to be near the water. This dry lab offers an alternative, using authentic data and a simulation of plankton sampling. From the types of organisms found in the sample, middle school students can infer relationships in the biological and physical…

  5. Variation of baroclinicity over the spring-neap cycle in the Sumjin River estuary, Korea

    NASA Astrophysics Data System (ADS)

    Cho, Eun-Byeol; Cho, Yang-Ki; Seo, Gwang-Ho; Tak, Yong-Jin; Kim, Bong-Kuk

    2015-04-01

    Vertical velocity profiles and hydrography were intensively observed using Acoustic Doppler Current Profilers and CTD to understand the variation of baroclinicity over the spring-neap tidal cycle in the Sumjin River estuary, Korea. The Sumjin River estuary is a natural estuary in Korea. The river is 212km long, a drainage area is nearly 4,896km2 and the yearly mean discharge is 86.3m3/s. The Sumjin River estuary experiences a transition from partially- or well-mixed during spring tides (St < 0.15), but stratified conditions during neap tides (St > 0.32) based on the stratification parameter (St) which is the salinity difference between surface and bottom (?S) divided by the depth averaged salinity . The CTD observation cruises were taken at flood and ebb during neap tide and spring tide. The horizontal density gradient changes over fortnightly tidal cycle. The horizontal density gradient is small during neap tide. However it during spring tide dramatically increases about six to ten times larger than neap tide. The mean flow in the Sumjin River estuary displayed typical estuarine circulation which the surface layer flows seaward and the bottom layer flows landward. However, the snapshots of the velocity profiles showed dramatic changes with the tide. Velocity shear is strong during spring tides when the tidal range was at a maximum, while velocity shear is weak during neap tides when the tidal range was at a minimum. The change of tidal range induces baroclinic variations. An analytical model was applied to evaluate the effect of horizontal density on the velocity profile variation. The velocity profiles are determined by river discharge, horizontal density variations, and tide. Density variations act as a baroclinic pressure gradient, whereas the river discharge and tides act as a horizontal barotropic pressure gradient. The velocity profiles calculated by the analytical model suggest that the variation of baroclinicity over the spring-neap cycle is mainly caused by the horizontal density gradient.

  6. MARSHALL ST. E. ADAMS ST.

    E-print Network

    McConnell, Terry

    ESTRY DR. SIMS DR. CAMPUSDRIVE MOUNT O LY M P U S D R IVE OSTROMAVE. EUCLID AVE. LIVINGSTONAVE Watson 804 S.U. Bookstore Walnut SCIS 400 Ostrom U.S. Post Office Bank Bank Mall University College Barry Park MEADOWBROOK DR . E. FAYETTE ST. ERIE BLVD. E. E. GENESEE ST. JAMES ST. LANCASTERAVE

  7. D.H. Lawrence and modern destructiveness.

    PubMed

    Gutierrez, D

    1980-01-01

    This article discusses twentieth century societal destructiveness as reflected in four key prose works by D.H. Lawrence--the novels Sons and Lovers, Women in Love, Lady Chatterley's Lover and the early travel book Twilight in Italy. Sons and Lovers, which projects the young Lawrence persona's struggle between life and death, partly accounts for a deepening sensitivity to life and death in modern society in Lawrence's subsequent works. It is seen that Lawrence's writings depict the perilous trends today towards the mechanization of our fundamental being, and the resultant life-threatening qualities of sensationalism and reduction of the individual inner life. PMID:7008281

  8. Macrobenthos composition, distribution and abundance within Sungai Pulai estuary, Johor, Malaysia

    NASA Astrophysics Data System (ADS)

    Shi, Guan Wan; Min, Lee Di; Ghaffar, Mazlan Abd; Ali, Masni Md; Cob, Zaidi Che

    2014-09-01

    Macrobenthos are very useful organisms for monitoring marine environmental and widely use in marine ecology research. They are able to monitor the difference phase in the recovery stage of disturbed sites by appear different species macrobenthos after the cessation of the impact. Univariate and multivariate methods were use to study the macrobenthos community within Sungai Pulai estuary, Johor, Malaysia. Five sub-samples were taken at each sampling sites by using 10 cm diameter corer. Crustaceans were the most abundant at Tanjung Adang (St. 1) and the station of non-seagrass area (St. 2) while polychaetes were the most abundant at Merambong Shoal (St. 3). Higher density of macrobenthos was found at St.3 followed by St. 1 and St. 2. The commonly used population indices such as diversity, richness, evenness and dominance were employed to determine the differences in diversity and abundance of macrobenthos. The diversity, richness and evenness index values showed slight increment from Station 1 to Station 3, while the dominance index decreasing trend from Station 1 to Station 3. A total 21 polychaete families were collected in Sungai Pulai estuary, which was dominated by the Spionidae, Capitellidae and Glyceridae. Cluster (Bray-Curtis similarities) analyses revealed that the Tanjung Adang and Merambong Shoal population were clearly separated from the station non-seagrass. For the time being factors that influence the pattern of distribution of the macrobenthos cannot be determined and subjected to further studies.

  9. Lawrence Livermore National Laboratory 2007 Annual Report

    SciTech Connect

    Chrzanowski, P; Walter, K

    2008-04-25

    Lawrence Livermore National Laboratory's many outstanding accomplishments in 2007 are a tribute to a dedicated staff, which is shaping the Laboratory's future as we go through a period of transition and transformation. The achievements highlighted in this annual report illustrate our focus on the important problems that affect our nation's security and global stability, our application of breakthrough science and technology to tackle those problems, and our commitment to safe, secure, and efficient operations. In May 2007, the Department of Energy (DOE) awarded Lawrence Livermore National Security, LLC (LLNS), a new public-private partnership, the contract to manage and operate the Laboratory starting in October. Since its inception in 1952, the Laboratory had been managed by the University of California (UC) for the DOE's National Nuclear Security Administration (NNSA) and predecessor organizations. UC is one of the parent organizations that make up LLNS, and UC's presence in the new management entity will help us carry forward our strong tradition of multidisciplinary science and technology. 'Team science' applied to big problems was pioneered by the Laboratory's co-founder and namesake, Ernest O. Lawrence, and has been our hallmark ever since. Transition began fully a year before DOE's announcement. More than 1,600 activities had to be carried out to transition the Laboratory from management by a not-for-profit to a private entity. People, property, and procedures as well as contracts, formal agreements, and liabilities had to be transferred to LLNS. The pre-transition and transition teams did a superb job, and I thank them for their hard work. Transformation is an ongoing process at Livermore. We continually reinvent ourselves as we seek breakthroughs that impact emerging national needs. An example is our development in the late 1990s of a portable instrument that could rapidly detect DNA signatures, research that started with a view toward the potential threat of terrorist use of biological weapons. As featured in our annual report, activities in this area have grown to many important projects contributing to homeland security and disease prevention and control. At times transformation happens in large steps. Such was the case when nuclear testing stopped in the early 1990s. As one of the nation's nuclear weapon design laboratories, Livermore embarked on the Stockpile Stewardship Program. The objectives are to ensure the safety, security, and reliability of the nation's nuclear weapons stockpile and to develop a science-based, thorough understanding of the performance of nuclear weapons. The ultimate goal is to sustain confidence in an aging stockpile without nuclear testing. Now is another time of major change for the Laboratory as the nation is resizing its nuclear deterrent and NNSA begins taking steps to transform the nuclear weapons complex to meet 21st-century national security needs. As you will notice in the opening commentary to each section of this report, the Laboratory's senior management team is a mixture of new and familiar faces. LLNS drew the best talent from its parent organizations--Bechtel National, UC, Babcock & Wilcox, the Washington Group Division of URS, and Battelle--to lead the Laboratory. We are honored to take on the responsibility and see a future with great opportunities for Livermore to apply its exceptional science and technology to important national problems. We will work with NNSA to build on the successful Stockpile Stewardship Program and transform the nation's nuclear weapons complex to become smaller, safer, more secure, and more cost effective. Our annual report highlights progress in many relevant areas. Laboratory scientists are using astonishing computational capabilities--including BlueGene/L, the world's fastest supercomputer with a revolutionary architecture and over 200,000 processors--to gain key insights about performance of aging nuclear weapons. What we learn will help us sustain the stockpile without nuclear testing. Preparations are underway to start experiments at

  10. 75 FR 34975 - Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ...Policy task force goals and in identifying focus areas for the estuary habitat restoration strategy, such as: climate adaptation restoration, socio-economic benefits of estuary habitat restoration, and geographic restoration...

  11. Comparison of Nutrient Drivers and Response Metrics in Oregon Estuaries

    EPA Science Inventory

    With the goal of assessing sensitivity to nutrient enrichment, we present a cross-estuary comparison of nutrient sources, levels, and biological responses (phytoplankton and macroalgae) for thirteen Oregon estuaries. Nitrogen levels in the upstream portions of the estuaries are ...

  12. MAPPING BATHYMETRY AND BOTTOM TYPE IN A SHALLOW ESTUARY

    EPA Science Inventory

    Bathymetry and bottom type are important in characterizing estuaries and their ecology but hard to map, especially in shallow estuaries. Acoustic backscattering was used to remotely sense these properties in the shallow Slocums River Estuary of Massachusetts. Acoustic pulses were...

  13. 14. Historic American Buildings Survey PHOTOCOPY OF EVERETT MILLS, LAWRENCE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Historic American Buildings Survey PHOTOCOPY OF EVERETT MILLS, LAWRENCE, MASS., INSURANCE SURVEY DRAWING n. d. From the collection of Factory Mutual Insurance Company, Norwood, Mass. - Lawrence Machine Shop, Union & Canal Streets, Lawrence, Essex County, MA

  14. Professor Charles E. Lawrence Division of Applied Mathematics

    E-print Network

    Professor Charles E. Lawrence Division of Applied Mathematics Center for Computational Molecular records (2014), Luan Lin, Deborah Khider, Lorraine E. Lisiecki, and Charles E. Lawrence, Paleoceanography, Rachel Maloney, Philipp Kapranov, Charles E. Lawrence, and Robert A. Reenan, Nature Structural

  15. 75 FR 34975 - Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... the Final Estuary Habitat Restoration Strategy (67 FR 71942). Section 106(f) of the Act authorizes the... National Oceanic and Atmospheric Administration RIN 0648-XX00 Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration Strategy; Request for Public Comment...

  16. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL 53811 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Ventilation Technologies Scoping of the United States Government or any agency thereof, or The Regents of the University of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. #12;VENTILATIONS STANDARDS

  17. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL-57236 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Review of Literature Related Government or any agency thereof, or The Regents of the University of California or any other sponsor. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. #12;Abstract This paper

  18. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    1 LBNL 57730 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Review of Residential Ventilation the Energy Commission passed upon the accuracy or adequacy of the information in this report. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. LBNL-57730 #12;3 Abstract

  19. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL-58713 LBNL-58713 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Report on Applicability of the United States Government or any agency thereof, or The Regents of the University of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. LBNL-58713 ii #12

  20. ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY

    E-print Network

    LBNL-59041 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Development of a Mathematical Air Government or any agency thereof, or The Regents of the University of California or any other sponsor. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. This work was also

  1. LAWRENCE RISK-BASED AIR SCREENING

    EPA Science Inventory

    The pediatric asthma rate in the city of Lawrence is the highest in the state of Massachusetts. This project will evaluate whether the cumulative risks due to the air pollution in Lawrence is contributing to the high asthma rates and other respiratory problems. The project will...

  2. Morphodynamic equilibrium of alluvial estuaries

    NASA Astrophysics Data System (ADS)

    Tambroni, Nicoletta; Bolla Pittaluga, Michele; Canestrelli, Alberto; Lanzoni, Stefano; Seminara, Giovanni

    2014-05-01

    The evolution of the longitudinal bed profile of an estuary, with given plan-form configuration, subject to given tidal forcing at the mouth and prescribed values of water and sediment supply from the river is investigated numerically. Our main goal is to ascertain whether, starting from some initial condition, the bed evolution tends to reach a unique equilibrium configuration asymptotically in time. Also, we investigate the morphological response of an alluvial estuary to changes in the tidal range and hydrologic forcing (flow and sediment supply). Finally, the solution helps characterizing the transition between the fluvially dominated region and the tidally dominated region of the estuary. All these issues play an important role also in interpreting how the facies changes along the estuary, thus helping to make correct paleo-environmental and sequence-stratigraphic interpretations of sedimentary successions (Dalrymple and Choi, 2007). Results show that the model is able to describe a wide class of settings ranging from tidally dominated estuaries to fluvially dominated estuaries. In the latter case, the solution is found to compare satisfactory with the analytical asymptotic solution recently derived by Seminara et al. (2012), under the hypothesis of fairly 'small' tidal oscillations. Simulations indicate that the system always moves toward an equilibrium configuration in which the net sediment flux in a tidal cycle is constant throughout the estuary and equal to the constant sediment flux discharged from the river. For constant width, the bed equilibrium profile of the estuarine channel is characterized by two distinct regions: a steeper reach seaward, dominated by the tide, and a less steep upstream reach, dominated by the river and characterized by the undisturbed bed slope. Although the latter reach, at equilibrium, is not directly affected by the tidal wave, however starting from an initial uniform stream with the constant 'fluvial' slope, the final equilibrium state is reached through an erosional wave, which leads to bed degradation of the upstream 'fluvial reach'. For a given river discharge, the length of the tidal reach increases quite rapidly with tidal amplitude, up to some threshold value of the tidal amplitude above which the length of the estuary becomes comparable with the length of the tidal wave. When the channel plan-form is convergent, deposition of sediments of fluvial origin in the funnel-shaped region drastically changes the equilibrium configuration. The effect of an increasing channel convergence is thus to induce bed aggradation close to the inlet. Nevertheless, tidal forcing only slightly changes the non-tidal profile. The effect of increasing tidal oscillations again leads to an increase of the bed slope at the inlet and to a general bed degradation upstream. The effects of varying sediment supply, flow discharge and river width in the upstream reach have also been investigated and play an important role. Further geomorphological implications of these results will be discussed at the meeting. References Dalrymple, R. W., and K. Choi (2007), Morphologic and facies trends through the fluvialmarine transition in tide-dominated depositional systems: A schematic framework for environmental and sequence-stratigraphic interpretation, Earth-Science Reviews, 81(3-4), 135-174, doi:10.1016/j.earscirev.2006.10.002. Seminara, G., M. Bolla Pittaluga, and N. Tambroni (2012), Morphodynamic equilibrium of tidal channels, Environmental Fluid Mechanics: Memorial Volume in Honour of Prof. Gerhard H. Jirka, 153-174

  3. A theoretical framework for analyzing the effect of external change on tidal dynamics in estuaries

    NASA Astrophysics Data System (ADS)

    CAI, H.; Savenije, H.; Toffolon, M.

    2013-12-01

    The most densely populated areas of the world are usually located in coastal areas near estuaries. As a result, estuaries are often subject to intense human interventions, such as dredging for navigation, dam construction and fresh water withdrawal etc., which in some areas has led to serious deterioration of invaluable ecosystems. Hence it is important to understand the influence of such interventions on tidal dynamics in these areas. In this study, we present one consistent theoretical framework for tidal hydrodynamics, which can be used as a rapid assessment technique that assist policy maker and managers to make considered decisions for the protection and management of estuarine environment when assessing the effect of human interventions in estuaries. Analytical solutions to the one-dimensional St. Venant equations for the tidal hydrodynamics in convergent unbounded estuaries with negligible river discharge can be cast in the form of a set of four implicit dimensionless equations for phase lag, velocity amplitude, damping, and wave celerity, as a function of two localized parameters describing friction and convergence. This method allows for the comparison of the different analytical approaches by rewriting the different solutions in the same format. In this study, classical and more recent formulations are compared, showing the differences and similarities associated to their specific simplifications. The envelope method, which is based on the consideration of the dynamics at high water and low water, can be used to derive damping equations that use different friction approximations. This results in as many analytical solutions, and thereby allows one to build a consistent theoretical framework. Analysis of the asymptotic behaviour of the equations shows that an equilibrium tidal amplitude exits reflecting the balance between friction and channel convergence. The framework is subsequently extended to take into account the effect of river discharge. Hence, the analytical solutions are applicable even in the upstream part of an estuary, where the influence of river discharge is remarkable. The proposed analytical solutions are transparent and practical, allowing a quantitative and qualitative assessment of human interventions (e.g., dredging, flow reduction) on tidal dynamics. Moreover, they are rapid assessment techniques that enable the users to set up a simple model and to understand the functioning of the system with a minimum of information required. The analytical model is illustrated in three large-scale estuaries with significant influence by human activities, i.e., the Scheldt estuary in the Netherlands, the Modaomen and the Yangtze estuaries in China. In these estuaries, the correspondence with observations is good, which suggests that the proposed model is a useful, yet realistic and reliable instrument for quick detection of the effect of human interventions on tidal dynamics and subsequent environmental issues, such as salt intrusion.

  4. NEW HAMPSHIRE ESTUARIES PROJECT MANAGEMENT PLAN, 2000

    EPA Science Inventory

    The Comprehensive Conservation and Management Plan of the New Hampshire Estuaries Project presents a broad framework and specific list of actions to protect and enhance the environmental quality of the estuaries of the State of New Hampshire. It is intended to be a guide for all ...

  5. NEW HAMPSHIRE ESTUARIES PROJECT MANAGEMENT PLAN

    EPA Science Inventory

    This Comprehensive Conservation and Management Plan of the New Hampshire Estuaries Project presents a broad framework and specific list of actions to protect and enhance the environmental quality of the estuaries of the State of New Hampshire. It is intended to be a guide for all...

  6. NEW HAMPSHIRE'S ESTUARIES, THE STATE OF

    EPA Science Inventory

    The State of the New Hampshire Estuary Report describes the region's valuable natural resources, explains how natural resources are linked to the cultural and economic well being of New Hampshire, and identifies threats to these resources. This State of the Estuaries Report summa...

  7. A Climate Ready Estuaries Vulnerability Assessment

    EPA Science Inventory

    The purpose of the the Climate Ready Estuaries program is to build capacity in the National Estuary Programs (NEPs) for local leadership and expertise to adapt to the effects of climate change through a joint effort with the NEPs and EPA.

    Background
    The Climate Ready...

  8. AFS Estuaries Section - A Successful Partnership

    EPA Science Inventory

    The Estuaries Section of the American Fisheries Society offers travel awards to students in support of their attendance and presentations at the AFS meeting. Since 2007, the Southern Association of Marine Laboratories has partnered with the Estuaries Section to sponsor two stude...

  9. Estuary Habitat Restoration Council ACTION PLAN

    E-print Network

    US Army Corps of Engineers

    Estuary Habitat Restoration Council ACTION PLAN 2012 The purpose of this Action Plan is to support the 2012 Estuary Habitat Restoration (EHR) Strategy by identifying specific actions and milestones Service (NRCS). Several federal agencies fund and implement coastal and estuarine habitat restoration

  10. Dissolved Oxygen Data for Coos Estuary (Oregon)

    EPA Science Inventory

    The purpose of this product is the transmittal of dissolved oxygen data collected in the Coos Estuary, Oregon to Ms. Molly O'Neill (University of Oregon), for use in her studies on the factors influencing spatial and temporal patterns in dissolved oxygen in this estuary. These d...

  11. HIGHLAND AVE OVERHILL ST

    E-print Network

    Mohaghegh, Shahab

    FORREST AVE BAIRD ST REID ST WATERST BEECHURSTAVE USHWY119HWY119 CHESTNUTST HIGHST WALNUT ST COURT ST Boreman Hall North 652 North High Street WVU Storage & Surplus Center PRT Station Walnut St. RFL House

  12. Dissolved oxygen in two Oregon estuaries: The importance of the ocean-estuary connection - May 16, 2011

    EPA Science Inventory

    We examined the role of the ocean –estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

  13. Lawrence Berkeley Lab Indexing Toolbox

    Energy Science and Technology Software Center (ESTSC)

    2003-09-08

    The Lawrence Berkeley Lab Indexing Toolbox is intended to be used in the context of X-ray crystallography experiments involving biological macromolecules. Macromolecules such as proteins form 3-dimensional periodic arrays (crystal) which in turn lead to lattice-like diffraction patterns when the crystal sample is irradiated with collimated X-rays from a synchrotron or other X-ray source. Once the diffraction pattern is captured on an imaging device the next step is to deduce the periodic nature of themore »crystal sample, along with its internal symmetry. this analysis, known as "indexing" is a well-studied problem. However, there are no other implementations designed to operate in an automated setting, in which the human experimentalist is not prosent to manually verify the results of indexing. In particular LABELIT uses three novel algorithms to facilitate automation: a more robust way to verify the position of the incident X-ray beam on the image, a better way to verify that the deduced lattice is consistent with the observed crystal lattice, and new method to deduce the internal symmetry from measurements of the lattice. Moreover, the algorithms are implemented in a Python framework that permits indexing to fail (in rare cases) without crashing the program, thus allowing the software to be incorporated in robotic systems where unattended operation is expected. It will be especially useful for high throughput operations at snychrotron beamlines.« less

  14. Salinity of the Delaware Estuary

    USGS Publications Warehouse

    Cohen, Bernard; McCarthy, Leo T., Jr.

    1962-01-01

    The purpose of this investigation was to obtain data on and study the factors affecting the salinity of the Delaware River from Philadelphia, Pa., to the Appoquinimink River, Del. The general chemical quality of water in the estuary is described, including changes in salinity in the river cross section and profile, diurnal and seasonal changes, and the effects of rainfall, sea level, and winds on salinity. Relationships are established of the concentrations of chloride and dissolved solids to specific conductance. In addition to chloride profiles and isochlor plots, time series are plotted for salinity or some quantity representing salinity, fresh-water discharge, mean river level, and mean sea level. The two major variables which appear to have the greatest effect on the salinity of the estuary are the fresh-water flow of the river and sea level. The most favorable combination of these variables for salt-water encroachment occurs from August to early October and the least favorable combination occurs between December and May.

  15. Water Column Methylation in Estuaries

    NASA Astrophysics Data System (ADS)

    Schartup, A. T.; Calder, R.; Soerensen, A. L.; Mason, R. P.; Balcom, P. H.; Sunderland, E. M.

    2014-12-01

    Methylmercury (MeHg) is a neurotoxin that bioaccumulates in aquatic food webs and affects humans and wildlife through fish consumption. Many studies have measured active methylation/demethylation in ocean margin sediments but few have reported similar rates for the marine water column. This presentation will review available evidence for water column methylation in estuaries, including new experimental measurements of methylation/demethylation rates from a deep subarctic fjord in Labrador Canada collected in Spring and Fall of 2012-2013. We used these and other data to construct a mass budget for MeHg in the estuary and show that water column methylation (with rates ranging from 1.5 to 2.8 % day-1), is the largest contributor, followed by inputs from rivers (4.9 mol year-1), to the in situ pool of MeHg available for uptake by biota. By contrast, the sediment in this system is a net sink for MeHg (-1.5 mol year-1). We discuss the relationship between observed MeHg and other ancillary environmental factors (organic carbon, sulfur and nutrients) as well as implications for the response time of fish to future changes in mercury inputs.

  16. Estimating bankfull discharge and depth in ungauged estuaries

    NASA Astrophysics Data System (ADS)

    Gisen, Jacqueline Isabella Anak; Savenije, Hubert H. G.

    2015-04-01

    It is difficult to measure river discharge accurately in an estuary, and particularly, in the region where the tidal flow dominates over the river discharge. River discharge is important for the morphology and hydrodynamics of estuaries as it influences the salt intrusion process, tidal dynamics, freshwater supply (water resources management), and the occurrence of floods. Here we try to derive river regime characteristics from the seaward end: the estuary. It is found that there are empirical relationships that link the geometry of an estuary to its river regime, which can be used to estimate river discharge characteristics with the least of data available. The aims of this study are: (1) to derive empirical relations between geometrical characteristics of estuaries and the bankfull discharge; (2) to explore a physical explanation for this relation; and (3) to estimate the bankfull discharge in estuaries. The physical connection between an estuary and its river regime is found by combining estuary shape analysis, tidal dynamic analysis, and Lacey's hydraulic geometry theory. The relationships found between the estuary depth, width, and bankfull river discharge have been tested in 23 estuaries around the world (including seven recently surveyed estuaries). From the analysis, it shows that the depth of an estuary is a function of the bankfull flood discharge to the power of 1/3, which is in agreement with Lacey's formula. This finding not only provides a method to estimate estuary depth, it also allows estimating flood discharge characteristics from readily available estuary shape indicators.

  17. EPA'S BENTHIC HABITAT DATA FOR YAQUINA ESTUARY

    EPA Science Inventory

    Scientists at EPA's National Health and Environmental Effects Research Laboratory, Western Ecology Division (WED) have been studying seafloor (benthic) habitats in Yaquina estuary for several years. Those studies were conducted as parts of several research projects, including: e...

  18. PECONIC ESTUARY PROGRAM TIDAL CREEK STUDY

    EPA Science Inventory

    EEA evaluated ten tidal creeks throughout the Peconic Estuary representing a wide range of watershed variables. Primary focus was directed towards the collection and analysis of the macrobenthic invertebrate communities of these ten tidal creeks. Analysis of the macrobenthic comm...

  19. Copper speciation in estuaries and coastal waters

    E-print Network

    Kogut, Megan Brook, 1972-

    2002-01-01

    The goals of this dissertation are to better understand the sources and the Cu binding ability of ligands that control Cu toxicity in estuaries and harbors, where elevated Cu concentrations have caused documented toxic ...

  20. The Peel Inlet-Harvey Estuary Study.

    ERIC Educational Resources Information Center

    Walker, Warren; Black, Ronald

    1979-01-01

    Describes how the department of physics of the Western Australian Institute of Technology (WAIT) has been involved in the Peel Inlet-Harvey Estuary study. An appendix which presents the departmental approach to curriculum matters is also included. (HM)

  1. Microplastic in three urban estuaries, China.

    PubMed

    Zhao, Shiye; Zhu, Lixin; Li, Daoji

    2015-11-01

    Estuarine Microplastics (MPs) are limited to know globally. By filtering subsurface water through 330 ?m nets, MPs in Jiaojiang, Oujiang Estuaries were quantified, as well as that in Minjiang Estuary responding to Typhoon Soulik. Polymer matrix was analyzed by Raman spectroscopy. MP (<5 mm) comprised more than 90% of total number plastics. The highest MPs density was found in Minjiang, following Jiaojiang and Oujiang. Fibers and granules were the primary shapes, with no pellets found. Colored MPs were the majority. The concentrations of suspended microplastics determine their bioavailability to low trophic organisms, and then possibly promoting the transfer of microplastic to higher trophic levels. Polypropylene and polyethylene were the prevalent types of MPs analyzed. Economic structures in urban estuaries influenced on MPs contamination levels. Typhoon didn't influence the suspended MP densities significantly. Our results provide basic information for better understanding suspended microplastics within urban estuaries and for managerial actions. PMID:26312741

  2. Health of white sucker within the St. Louis River area of concern associated with habitat usage as assessed using stable isotopes

    EPA Science Inventory

    In Spring 2011, 200 adult white sucker were collected in four areas of the St. Louis River Area of Concern (AOC), located in Minnesota and Wisconsin, USA. The areas included the upper AOC as a reference area, the upper estuary, St. Louis Bay and Superior Bay. Grossly visible abno...

  3. Mixing in the Amazon estuary

    NASA Astrophysics Data System (ADS)

    Bezerra, M. O.

    2010-05-01

    The research area of this work is located at the estuary of the Amazon River (Brazil), near the river mouth. The results of air movement analysis on the surface atmospheric circulation over the Mouth of the Amazonas River, salinity and temperature measures as well as measurements of currents, carried out along a longitudinal section in the navigation canal region of the Northern Bar of the Amazon River (Barra Norte do Rio Amazonas) in June 2006, during the river flood season in the quadrature tide. The dynamics effects affect hydrodynamic,meteorological and hydrographical parameters at the river mouth. The conclusion drawn include that: a) the saline wedge-type stratification can be detected approximately 100km away from the mouth of the Amazon River during the end of the rainy season in the quadrature tide; b) probably, at the Amazon estuary the quadrature entrainment processes are dominant and they are the ones responsible for increased salinity detected in the surface layer, whereas turbulence scattering mixing is not so important. c) The large flow of fresh water from the Amazon River at the end of the rainy season implies the displacement of the saline front position over the internal Amazon continental platform, and d) The tidal wave shows a positive asymmetry in the canal, with floods lasting less than in the ebb tide. This asymmetry decreases towards the ocean, eventually becoming reversed in the presence of a saline wedge. The speeds, however, have a negative asymmetry, with more intense ebb tides, due to the river flow and is more evident by the existence of quadrature tides.

  4. Estuaries.

    ERIC Educational Resources Information Center

    Awkerman, Gary L.

    This publication is designed for use in standard science curricula to develop oceanologic manifestations of certain science topics. Included are teacher guides, student activities, and demonstrations designed to impart ocean understanding to high school students. When the student has completed this unit, he should be able to: (1) define an…

  5. The Estuary Book: A Guide to Promoting Understanding and Regional Management of Maine's Estuaries and Embayments.

    ERIC Educational Resources Information Center

    Ruffing, Jenny

    The objective of this document is to provide information about estuaries, the impact of uses on the environmental health of an estuary, and what communities and concerned individuals can do to manage and protect their local estuarine resources successfully. Much of the information presented here pertains to other embayments along the Maine coast…

  6. Fish track wastewater pollution to estuaries.

    PubMed

    Schlacher, Thomas A; Liddell, Ben; Gaston, Troy F; Schlacher-Hoenlinger, Monika

    2005-08-01

    Excess nitrogen is a forceful agent of ecological change in coastal waters, and wastewater is a prominent source of nitrogen. In catchments where multiple sources of nitrogen pollution co-exist, biological indicators are needed to gauge the degree to which wastewater-N can propagate through the receiving food webs. The purpose of this study was to test whether estuarine fish are suitable as indicators of sewage-N pollution. Fish were analysed from three estuaries within a 100-km strip on the Australian East Coast. The estuaries differ substantially in wastewater loading: (1) the Maroochy Estuary receives a large fraction of the local shire's treated sewage, (2) the Mooloolah Estuary has no licensed treated wastewater outfalls but marinas/harbours and storm-water may contribute nitrogen, and (3) the Noosa Estuary which neither receives licensed discharges nor has suspected wastewater loads. Sampling for fish included both high rainfall ('wet' season) and low rainfall ('dry' season) periods. Muscle-delta15N was the variable predicted to respond to treated wastewater loading, reflecting the relative enrichment in 15N resulting from the treatment process and distinguishing it from alternative N sources such as fertiliser and natural nitrogen inputs (both 15N-depleted). Of the 19 fish species occurring in all three estuaries, those from the Maroochy Estuary had significantly elevated delta15N values (up to 9.9 per thousand), and inter-estuarine differences in fish-delta15N were consistent across seasons. Furthermore, not only did all fish from the estuary receiving treated wastewater carry a very distinctive sewage-N tissue signal, but enriched muscle-delta15N was also evident in all species sampled from the one estuary in which sewage contamination was previously only suspected (i.e. the Mooloolah Estuary: 0.2-4.8 per thousand enrichment over fish from reference system). Thus, fish-delta15N is a suitable indicator of wastewater-N not only in systems that receive large loads, but also for the detection of more subtle nitrogen inputs. Arguably, fish may be preferred indicators of sewage-N contamination because they: (1) integrate nitrogen inputs over long time periods, (2) have an element of 'ecological relevance' because fish muscle-delta15N reflect movement of sewage-N through the food chain, and (3) pollution assessments can usually be based on evidence from multiple species. PMID:15891851

  7. Estuaries. Estuaries are places where fresh and salt water mix. Typically they occur where rivers enter the sea. Estero Limantour, Drakes' Bay, Point Reyes National Seashore.

    E-print Network

    Richerson, Peter J.

    Estuaries Lecture 18 #12;Estuaries. Estuaries are places where fresh and salt water mix. Typically;Estuary development is quite pronounced in to today's world. During the Pleistocene, low sea level stands,000 years ago, these valleys flooded to form estuaries like the Chesapeake and Delaware Bays. If the sea

  8. MOBILE BAY NATIONAL ESTUARY PROGRAM COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

    EPA Science Inventory

    In simplest terms, an estuary is defined as an area where rivers meet the sea. They are transitional zones where freshwater rivers meet tidally influenced marine waters. Estuaries are considered environmentally and economically important because of their exceptional biological di...

  9. 78 FR 56610 - Drawbridge Operation Regulations; Reynolds Channel, Lawrence, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-13

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Reynolds Channel, Lawrence, NY... operation of the Atlantic Beach Bridge, mile 0.4, across Reynolds Channel, at Lawrence, New York. This... Atlantic Beach Bridge, across Reynolds Channel, mile 0.4, at Lawrence, New York, has a vertical...

  10. ACTIVITY REPORT Ernest Orlando Lawrence Berkeley National Laboratory

    E-print Network

    ACTIVITY REPORT 1997/98 March 1999 Ernest Orlando Lawrence Berkeley National Laboratory University. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. #12;ADVANCED LIGHT. DE-AC03-76SF00098. March 1999 Ernest Orlando Lawrence Berkeley National Laboratory University

  11. A PRIL 2000 Ernest Orlando Lawrence Berkeley National Laboratory

    E-print Network

    A PRIL 2000 Ernest Orlando Lawrence Berkeley National Laboratory University of California.S. Department of Commerce, 5285 Port Royal Road, Springfield,VA 22161. Ernest Orlando Lawrence Berkeley National00098. April 2000 Ernest Orlando Lawrence Berkeley National Laboratory University of California Berkeley

  12. Phytoplankton Ecology of North Carolina Estuaries Michael A. Mallin

    E-print Network

    Mallin, Michael

    Phytoplankton Ecology of North Carolina Estuaries Michael A. Mallin Estuaries, Vol. 17, No. 3. (Sep%3APEONCE%3E2.0.CO%3B2-H Estuaries is currently published by Estuarine Research Federation. Your use@jstor.org. http://www.jstor.org Wed Mar 26 15:41:46 2008 #12;Estuaries Vol. 17, No. 3, p. 561-574 September 1994

  13. Breaking ground in Canaan: African-American community in Lawrence, 1870-1920

    E-print Network

    Fowler III, Paul E.

    2014-04-01

    and initially dependent on the charity of the existing white and black communities of Lawrence. Prior to 1870, Missouri was the primary contributor to the black population of Kansas. By the mid- 1870s, Kentucky and Tennessee became the first states... when they voted to extend charity at a meeting held at Fraser Hall in 1879.15 John M. F. Stinger, a Kentucky Radical Republican, also wrote letters to Gov. St. John requesting he convince others in the North of their moral duty in assisting...

  14. Struggle for the Soul: John Lawrence Childs

    ERIC Educational Resources Information Center

    Stallones, Jared

    2010-01-01

    John Lawrence Childs was born in Eau Claire, Wisconsin on January 11, 1889, the second child of John Nelson Childs and Helen Janette (Nettie) Smith. In childhood Childs absorbed the values of industry, democracy, and a traditional, but socially conscious, religion. Childs was a Methodist and an intensely private person not given to talking about…

  15. SAN FRANCISCO ESTUARY PROJECT COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

    EPA Science Inventory

    The Estuary, a significant natural resource, San Francisco Bay and the Delta combine to form the West Coast's largest estuary. The Estuary conveys the waters of the Sacramento and San Joaquin Rivers to the Pacific Ocean. It encompasses roughly 1,600 square miles, drains over 40 p...

  16. UNCORRECTED 2 Iron isotope fractionation in subterranean estuaries

    E-print Network

    UNCORRECTED PROOF 1 2 Iron isotope fractionation in subterranean estuaries 3 Olivier Rouxel a estuaries, like their river-seawater counterparts, are strongly controlled by 10 non-conservative behavior estuary of Waquoit Bay on Cape Cod, USA demonstrate extensive precipitation of groundwater-borne dissolved

  17. Personal connections with rivers, estuaries and wetlands in Victoria

    E-print Network

    Roe, Paul

    Personal connections with rivers, estuaries and wetlands in Victoria Waterway My Victorian #12 importance of our rivers, creeks, wetlands and estuaries (i.e. waterways). The research, undertaken and estuaries · our knowledge of what makes a waterway healthy · what we Victorians do / are prepared to do

  18. The Estuary Guide. Level 3: High School. Draft.

    ERIC Educational Resources Information Center

    Alexander, Glen; And Others

    Estuaries are marine systems that serve as nurseries for animals, links in the migratory pathways, and habitat for a complex community of organisms. This curriculum guide intended for use at the high school level seeks to teach what estuaries are; provide opportunities to practice decision-making that affects estuaries; and encourage students to…

  19. Environmental flow assessments for transformed estuaries

    NASA Astrophysics Data System (ADS)

    Sun, Tao; Zhang, Heyue; Yang, Zhifeng; Yang, Wei

    2015-01-01

    Here, we propose an approach to environmental flow assessment that considers spatial pattern variations in potential habitats affected by river discharges and tidal currents in estuaries. The approach comprises four steps: identifying and simulating the distributions of critical environmental factors for habitats of typical species in an estuary; mapping of suitable habitats based on spatial distributions of the Habitat Suitability Index (HSI) and adopting the habitat aggregation index to understand fragmentation of potential suitable habitats; defining variations in water requirements for a certain species using trade-off analysis for different protection objectives; and recommending environmental flows in the estuary considering the compatibility and conflict of freshwater requirements for different species. This approach was tested using a case study in the Yellow River Estuary. Recommended environmental flows were determined by incorporating the requirements of four types of species into the assessments. Greater variability in freshwater inflows could be incorporated into the recommended environmental flows considering the adaptation of potential suitable habitats with variations in the flow regime. Environmental flow allocations should be conducted in conjunction with land use conflict management in estuaries. Based on the results presented here, the proposed approach offers flexible assessment of environmental flow for aquatic ecosystems that may be subject to future change.

  20. Estuaries and coastal waters need help

    SciTech Connect

    Levenson, H.

    1987-11-01

    For years, our marine environments-estuaries, coastal waters, and the open ocean-have been used extensively by coastal communities and industries for the disposal of various wastes. Historically, marine waste disposal has been relatively cheap and has solved some short-term waste-management problems; however, its consequences include a general trend toward environmental degradation, particularly in estuaries and coastal waters. Thus, without protective measures, the next few decades will witness degradation in many estuaries and some coastal waters around the country. The extent of current degradation varies greatly around the country. Although it is difficult to ascertain cause and effect relationships, enough evidence exists to conclude that the pollutants in question include disease-causing microorganisms, oxygen-demanding substances, particulate material, metals, and organic chemicals. Two statutes form the basis of most federal regulatory efforts to combat marine pollution: the Marine Protection, Research, and Sanctuaries Act (MPRSA) and the Clean Water Act (CWA). The MPRSA regulates the dumping of wastes in coastal and open-ocean waters, whereas the CWA has jurisdiction over pipeline discharges in all marine waters, wastes dumped in estuaries, and runoff. Many people consider that the passage and implementation of these two acts and their ensuing amendments established a statutory structure sufficient to protect the nation's waters from pollution. However, these provisions have not protected some estuaries and coastal waters from degradation.

  1. Prediction in ungauged estuaries: An integrated theory

    NASA Astrophysics Data System (ADS)

    Savenije, Hubert H. G.

    2015-04-01

    Many estuaries in the world are ungauged. The International Association of Hydrological Sciences completed its science decade on Prediction in Ungauged Basins (PUB) in 2012 (Hrachowitz et al.). Prediction on the basis of limited data is a challenge in hydrology, but not less so in estuaries, where data on fundamental processes are often lacking. In this paper, relatively simple, but science-based, methods are presented that allow researchers, engineers, and water managers to obtain first-order estimates of essential process parameters in estuaries, such as the estuary depth, the tidal amplitude, the tidal excursion, the phase lag, and the salt water intrusion, on the basis of readily obtainable information, such as topographical maps and tidal tables. These apparently simple relationships are assumed to result from the capacity of freely erodible water bodies to adjust themselves to external drivers and to dissipate the free energy from these drivers as efficiently as possible. Thus, it is assumed that these systems operate close to their thermodynamic limit, resulting in predictable patterns that can be described by relatively simple equations. Although still much has to be done to develop an overall physics-based theory, this does not prevent us from making use of the empirical "laws" that we observe in alluvial estuaries.

  2. Seasonal dissolved inorganic nitrogen and phosphorus budgets for two sub-tropical estuaries in south Florida, USA

    NASA Astrophysics Data System (ADS)

    Buzzelli, C.; Wan, Y.; Doering, P. H.; Boyer, J. N.

    2013-10-01

    Interactions among geomorphology, circulation, and biogeochemical cycling determine estuary responses to external nutrient loading. In order to better manage watershed nutrient inputs, the goal of this study was to develop seasonal dissolved inorganic nitrogen (DIN) and phosphorus (DIP) budgets for the two estuaries in south Florida, the Caloosahatchee River estuary (CRE) and the St. Lucie Estuary (SLE), from 2002 to 2008. The Land-Ocean Interactions in the Coastal Zone (LOICZ) approach was used to generate water, salt, and DIN and DIP budgets. Results suggested that internal DIN production increases with increased DIN loading to the CRE in the wet season. There were hydrodynamic effects as water column concentrations and ecosystem nutrient processing stabilized in both estuaries as flushing time increased to >10 d. The CRE demonstrated heterotrophy (net ecosystem metabolism or NEM < 0.0) across all wet and dry season budgets. While the SLE was sensitive to DIN loading, system autotrophy (NEM > 0.0) increased significantly with external DIP loading. This included DIP consumption and a bloom of a cyanobacterium (Microcystis aeruginosa) following hurricane-induced discharge to the SLE in 2005. Additionally, while denitrification provided a microbially-mediated N loss pathway for the CRE, this potential was not evident for the SLE where N2 fixation was favored. Disparities between total and inorganic loading ratios suggested that the role of dissolved organic nitrogen (DON) should be assessed for both estuaries. Nutrient budgets indicated that net internal production or consumption of DIN and DIP fluctuated with inter- and intra-annual variations in freshwater inflow, hydrodynamic flushing, and primary production. The results of this study should be included in watershed management plans in order to maintain favorable conditions of external loading relative to internal material cycling in both dry and wet seasons.

  3. St JamesSt JamesSt James ROADSCOTSWOOD ROAD

    E-print Network

    Newcastle upon Tyne, University of

    SCOTSW OOD RD St Nicholas Cathedral Castle Keep Black Gate & Moot Hall Guildhall St Mary's Heritage Terrace Jesmond Road Jesmond Road Bernicia Halls Bernicia Halls Joseph Cowen Halls Joseph Cowen Halls

  4. National Estuary Program after four years: A report to congress

    SciTech Connect

    Not Available

    1992-04-01

    The National Estuary Program After Four Years: A Report to Congress is a status report on the National Estuary Program (NEP) and the seventeen Management Conferences that are part of the NEP. The Report is divided into: Part I Meeting a Need: The National Estuary Program; Part II Understanding Estuaries: The Key to Better Management; Part III Managing Estuaries: The Best Methods; Part IV Assessing the NEP: What Has Been Learned; Part V Looking to the Future: Trends and Needs; and Part VI Moving Ahead: The NEP Projects.

  5. PECONIC ESTUARY: AN ASSESSMENT OF SHELLFISH RESOURCES IN THE TRIBUTARIES AND EMBAYMENTS OF THE PECONIC ESTUARY

    EPA Science Inventory

    Executive Summary Historically, the Peconic Estuary's shellfish resources have supported significant fisheries for a number of species including hard clams, oysters and bay scallops. However, distribution and abundance data for the tributaries and embayments within the Peconic Es...

  6. National estuary program guidance: Technical characterization in the National Estuary Program

    SciTech Connect

    Not Available

    1994-06-01

    Estuaries are waterways, such as bays and sounds, where fresh water drained from the surrounding watershed mixes with salt water from the ocean. Section 320 of the Clean Water Act established the National Estuary Program (NEP) to identify nationally significant estuaries threatened by pollution, development, or overuse and to promote the preparation of comprehensive management plans to ensure their ecological integrity. The program's goals are protection and improvement of water quality and enhancement of living resources. To reach these goals, the Administrator of the U.S. Environmental Protection Agency (EPA) convenes management conferences for each estuary in the NEP to provide a forum for consensus building and problem solving among interested agencies and user groups.

  7. Obituary: Lawrence Hugh Aller, 1913-2003

    NASA Astrophysics Data System (ADS)

    Kaler, James B.

    2003-12-01

    The announcement still lies in my inbox: ``Lawrence Aller died last Sunday." On 16 March 2003, one of the world's fine astronomers passed away at the age of 89, leaving behind a legacy that will ripple as long as there are students of the celestial science, one that incorporated observation, theory, education, care, decency, and kindness. Lawrence was born in the humblest of conditions in Tacoma, Washington, on 24 September 1913. His mother, Lella (Belle) Allen, was a homemaker and his father Leslie Aller, was an occassional printer and gold prospector who thought that the use of the mind was a waste of time. With fierce persistence and dedication, Lawrence pulled off a feat that would probably not be possible now: getting into college without having finished high school, the result of being dragged to work in his father's primitive gold mining camp. His interest, sparked by leaflets from the Astronomical Society of the Pacific and by Russell, Dugan, and Stewart's venerable textbook, led him to a correspondence, and finally a meeting, with Donald Menzel of Harvard, who persuaded the admissions director of the University of California at Berkeley to admit him in 1932. From there, Lawrence went on to graduate school at Harvard and the Harvard Society of Fellows, where he studied with Menzel and developed his interest in stellar and nebular astronomy. After working in the War effort, he made his professorial debut at Indiana University, where he stayed until 1948 before leaving for the University of Michigan. Residing there for the next 14 years, he established his research reputation and helped develop the Michigan graduate program. In 1962, the opportunity arose to return to California, to UCLA, where he again was instrumental in founding a PhD program. There he stayed, through his retirement in 1984, doing research right up to the end. Eight other schools received him as visiting professor. Lawrence knew that to make inroads into astronomy, he needed to apply physics to the observations, which he ardently sought. Little pleased him more than gathering photons, except perhaps for making atomic calculations with which he could analyze spectra. His real love was gaseous nebulae, specifically planetary nebulae (which he called his ``hobby"), the graceful shells of gas surrounding dying stars that are making their transitions to becoming white dwarfs. His range of simultaneous research projects was staggering. Having been an undergraduate student at Michigan in the late 1950s, I followed him to UCLA to work on my doctorate. When I arrived, I found him engaged in stellar spectroscopy, solar research, nebular theory, nebular observations (he tossed a box of plates at me and said in effect, ``here is your thesis"), and of all things Mie scattering theory to explain the zodiacal light! A list of his discoveries and influences is impressive. A sample: Lawrence played a major role in Menzel's group, which produced the famed ``Physical Processes in Gaseous Nebulae," an 18-part series that ran in the Astrophysical Journal from 1937 to 1945 and that explained nebular spectra. He was among the first to promulgate what in the 1940s was utter heresy, that the chemical compositions of stars could differ from one another. He was the first to observe gradients in spiral galaxies, which ultimately turned out to be the result of abundance variations. David Bohm and Lawrence established the existence of Maxwellian velocity distributions in nebular plasmas. Leo Goldberg, Edith Müller, and he were instrumental in establishing the chemical composition of the Sun. His observations of planetaries were legion. Never content with current observational and analytical capabilities, he sought out the latest equipment, from image tubes through CCDs to the best computers, ever looking ahead. His work was honored in 1992, when he received the American Astronomical Society's Russell Prize. Perhaps Lawrence's greatest legacy involved his teaching and writing. At Michigan, he taught a two-semester course in advanced general astronomy that

  8. Dr. Tom Lawrence: a life in chiropractic

    PubMed Central

    Keating, Joseph C

    2005-01-01

    He dwelt within the chiropractic orbit from the cradle to the grave. Second-generation chiropractor Tom Lawrence was a successful professional and family man who followed in his father’s footsteps and fought the good fight to improve chiropractic within his state and nation. His passing closes a chapter of living memory of the middle years of the first chiropractic century. PMID:17549212

  9. Lawrence Berkeley Laboratory 1993 Site Environmental Report

    SciTech Connect

    Not Available

    1994-05-01

    This annual Site Environmental Report summarizes Lawrence Berkeley Laboratory`s (LBL`s) environmental activities in calendar year (CY) 1993. The purpose of this report is to characterize site environmental management performance, confirm compliance status with environmental standards and requirements, and highlight significant programs and efforts. Its format and content are consistent with the requirements of the US Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

  10. Geothermal programs at Lawrence Livermore National Laboratory

    SciTech Connect

    Kasameyer, P.W.; Younker, L.W.

    1987-07-10

    Lawrence Livermore National Laboratory has a number of geothermal programs supported through two offices in the Department of Energy: the Office of Renewable Technologies, Geothermal Technologies Division, and the Office of Basic Energy Sciences, Division of Engineering, Mathematics and Geosciences. Within these programs, we are carrying out research in injection monitoring, optical instrumentation for geothermal wells, seismic imaging methods, geophysical and drilling investigations of young volcanic systems in California, and fundamental studies of the rock and mineral properties.

  11. Life sciences: Lawrence Berkeley Laboratory, 1988

    SciTech Connect

    Not Available

    1989-07-01

    Life Sciences Research at LBL has both a long history and a new visibility. The physics technologies pioneered in the days of Ernest O. Lawrence found almost immediate application in the medical research conducted by Ernest's brother, John Lawrence. And the tradition of nuclear medicine continues today, largely uninterrupted for more than 50 years. Until recently, though, life sciences research has been a secondary force at the Lawrence Berkeley Laboratory (LBL). Today, a true multi-program laboratory has emerged, in which the life sciences participate as a full partner. The LBL Human Genome Center is a contribution to the growing international effort to map the human genome. Its achievements represent LBL divisions, including Engineering, Materials and Chemical Sciences, and Information and Computing Sciences, along with Cell and Molecular Biology and Chemical Biodynamics. The Advanced Light Source Life Sciences Center will comprise not only beamlines and experimental end stations, but also supporting laboratories and office space for scientists from across the US. This effort reflects a confluence of scientific disciplines --- this time represented by individuals from the life sciences divisions and by engineers and physicists associated with the Advanced Light Source project. And finally, this report itself, the first summarizing the efforts of all four life sciences divisions, suggests a new spirit of cooperation. 30 figs.

  12. San Francisco Estuary Institute 7770 Pardee Road

    E-print Network

    San Francisco Estuary Institute 7770 Pardee Road Oakland, CA 94621 (510) 746­7334 www Drawbridge (Courtesy of UCB and UCSB) 1857 Near the mouth of Alameda Creek 1896 Development of modern salt the origin of many of the early Euro-American salt pond complexes. Management for salt production most likely

  13. INDICATORS OF ECOSYSTEM INTEGRITY FOR ESTUARIES

    EPA Science Inventory

    Jordan, Stephen J. and Lisa M. Smith. In press. Indicators of Ecosystem Integrity for Estuaries. In: Proceedings of the Estuarine Indicators Workshop, 29-31 October 2003, Sanibel Island, FL. Sanibel-Captiva Conservation Foundation, Sanibel, FL. 23 p. (ERL,GB 1194).

    Ideal ...

  14. TAMPA BAY ESTUARY PROGRAM, 2004 IMPLEMENTATION REVIEW

    EPA Science Inventory

    The Tampa Bay Estuary Program and its partners have made measurable progress toward implementation of the adopted CCMP goals. Progress has occurred in the following areas: bay habitats, with an increase in seagrass, estuarine habitat restoration and preservation; water and sedime...

  15. VOLUNTEER ESTUARY MONITORING: A METHOD MANUAL

    EPA Science Inventory

    Executive Summary: This manual focuses on volunteer estuary monitoring. As concern over the well-being of the environment has increased during the past couple of decades, volunteer monitoring has become an integral part of the effort to assess the health of our nation’s wat...

  16. DELAWARE ESTUARY PROGRAM IMPLEMENTATION STREAMLINE REVIEW, 2002

    EPA Science Inventory

    The primary purpose of the Delaware Estuary Program implementation review (formerly known as the biennial review) has been to assist EPA in. making funding decisions for those NEPs that are in the post-CCMP, or implementation, phase, and to evaluate implementation progress. The i...

  17. Estuaries and Tidal Marshes. Habitat Pac.

    ERIC Educational Resources Information Center

    Fish and Wildlife Service (Dept. of Interior), Washington, DC.

    This educational packet consists of an overview, three lesson plans, student data sheets, and a poster. The overview examines estuaries and tidal or salt marshes by discussing the plants and animals in these habitats, marsh productivity, benefits and management of the habitats, historical aspects, and development and pollution. A glossary and list…

  18. Listening to Estuary English in Singapore

    ERIC Educational Resources Information Center

    Deterding, David

    2005-01-01

    In Singapore, many people are not familiar with Estuary English (EE), the variety of English becoming popular in much of southern England. In the current study, when students listened to interviews with EE speakers and were asked to transcribe orthographically what they heard, most of them had severe problems. Features of pronunciation that…

  19. Padilla Bay: The Estuary Guide. Level 2.

    ERIC Educational Resources Information Center

    Friesem, Judy; Lynn, Valerie, Ed.

    Estuaries are marine systems that serve as nurseries for animals, links in the migratory pathways, and habitat for a complex community of organisms. This curriculum guide intended for use at the middle school level is designed for use with the on-site program developed by the Padilla Bay National Esturine Research Reserve (Washington). The guide…

  20. BCG Approaches for Improved Management of Estuaries

    EPA Science Inventory

    Estuaries and other complex aquatic systems are exposed to a variety of stressors that act at several scales, but are managed piecemeal - - often resulting in a “death by 1000 cuts” caused by cumulative impacts to these valued resources. To address this, managers need tools that...

  1. Climate change and its impacts on estuaries

    EPA Science Inventory

    Past, present, and future research by WED scientists in the TEP region will be described to lay the foundation for examination of potential climate change effects on estuaries and the broader coastal zone in the Pacific Northwest (PNW). Results from National Coastal Assessments,...

  2. MODELING FINE SEDIMENT TRANSPORT IN ESTUARIES

    EPA Science Inventory

    A sediment transport model (SEDIMENT IIIA) was developed to assist in predicting the fate of chemical pollutants sorbed to cohesive sediments in rivers and estuaries. Laboratory experiments were conducted to upgrade an existing two-dimensional, depth-averaged, finite element, coh...

  3. Kaua'i: Streams and Estuaries.

    ERIC Educational Resources Information Center

    Hawkins, John, Ed.; Murakami, Colleen, Ed.

    Designed to help teachers develop students' awareness and understanding of some of Hawaii's endangered aquatic resources, this module contains activities and instructional suggestions for use with intermediate as well as high school students. The module is divided into two sections which explore the streams and estuaries of Kauai. Activities in…

  4. THE ECOLOGICAL CONDITION OF VERACRUZ, MEXICO ESTUARIES

    EPA Science Inventory

    During June and July, 2002, forty-seven stations were sampled within estuaries along the gulf coast of the state of Veracruz, MX, using a probabilistic survey design and a common set of response indicators. The objective of the study was to collect information to assess the condi...

  5. Reversing circulation patterns in a tropical estuary

    NASA Astrophysics Data System (ADS)

    Valle-Levinson, Arnoldo; Bosley, Kathryn T.

    2003-10-01

    A combination of current velocity and water density measurements was used to characterize the basic patterns of water exchange in the Gulf of Fonseca, a tropical estuary on the Pacific Ocean side of Central America. The measurements were obtained during spring and neap tides in March (dry season) and June (wet season) of 2001 and consisted of profiles of current velocity and density along four transects. From mid-March to mid-April a time series of hourly surface current velocity maps was also obtained with a high-frequency radar system of two antennas. The sampling transects and the radar coverage concentrated in the portion of the estuary that has open communication with the ocean. During the dry season, water exchange at the entrance to the gulf suggested an inverse estuarine circulation that was more robust, and its dynamics were closer to geostrophy during neap than during spring tides. It is likely that salinity increased toward the tributaries of the system and then decreased within those tributaries because of the persistent influence of fresh water. In contrast, during the wet season, salinity decreased into the estuary, and the circulation resembled that of a typical estuary. In this season the fortnightly modulation of exchange flows was masked by wind effects, which also played a relevant role in the dynamics. The net volume inflows measured in both seasons suggested that the residence time of the Gulf of Fonseca varies from 2 weeks to 1 month.

  6. NE Pacific St. NE Pacific St.

    E-print Network

    Lake W ashington Ship Canal NE Pacific St. NE Pacific St. NE Boat St. 15th Ave NE 15thAveNE UniversityWayNE BrooklynAveNE NE Pacific St. MontlakeBlvdNE MontlakeBlvdNE Pacific Place NE University Burke-Gilman Trail METRO NW A CD D EF F GHI H J RR BB CC EE AA Rotunda Cafe Ocean Sciences Hitchcock

  7. Second International Symposium on the Biogeochemistry of Model Estuaries: Estuarine processes in global change. Final report

    SciTech Connect

    Windom, H.L.

    1991-12-31

    This report summarizes estuary events discussed at the symposium on biogeochemistry. Topics include; sedimentation, salinity, inputs and outputs of the estuary, effects of global change, and the need for effective sampling and modeling of estuaries.

  8. 78 FR 9887 - Proposed Information Collection; Comment Request; National Estuaries Restoration Inventory

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-12

    ...Collection; Comment Request; National Estuaries Restoration Inventory AGENCY: National...information collection. Collection of estuary habitat restoration project information...restoration project database mandated by the Estuary Restoration Act of 2000. The...

  9. 78 FR 46332 - Proposed Information Collection Request; Comment Request; National Estuary Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-31

    ...Collection Request; Comment Request; National Estuary Program AGENCY: Environmental Protection...collection request (ICR), ``National Estuary Program'' (EPA ICR No. 1500.08...comments to OMB. Abstract: The National Estuary Program (NEP) involves collecting...

  10. 75 FR 17382 - Small Takes of Marine Mammals Incidental to Specified Activities; Russian River Estuary Water...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-06

    ...Specified Activities; Russian River Estuary Water Level Management Activities, California...Authorization (IHA) to the Sonoma County Water Agency (herein after ``Agency...incidental to Russian River Estuary (Estuary) water level management and monitoring...

  11. Scales of variation in Pacific Northwest outer-coast estuaries This chapter provides an overview of the small, coastal-plain estuaries of the

    E-print Network

    Hickey, Barbara

    1 CHAPTER I Scales of variation in Pacific Northwest outer-coast estuaries This chapter provides an overview of the small, coastal-plain estuaries of the U.S. Pacific Northwest, a system of estuaries that, freshwater forcing, and tidal regime of these estuaries is described, with comparison to the more commonly

  12. ESTEEM - a New 'Hybrid Complexity' Model for Prediction of Estuary Morphological Evolution at Decadal to Centennial Scales

    NASA Astrophysics Data System (ADS)

    French, J.; Thornhill, G.; Burningham, H.

    2014-12-01

    Despite the wealth of historical and geological insights into coastal and estuarine landform behaviour, models capable of generating quantitative predictions at decadal to centennial scales are required if we are to meet the management challenges of the 21st century. Despite an emerging consensus that progress on this front is more likely to be made through models that are essentially synthesist in approach, the nature of marine forcing, especially in estuaries, means that it is frequently necessary to retain a degree of hydrodynamic complexity that can only be obtained via more reductionist models. We see great potential, therefore, in fusing these approaches rather than deploying them separately as end members of a modelling spectrum. This paper thus presents a novel approach to mesoscale estuary morphological evolution that combines physically complete 1-D simulation of tidal hydrodynamics, highly parameterised 2-D mechanistic representation of wave-driven tidal flat morphodynamics, and a largely empirical representation of 2-D variation in salt marsh deposition. This approach is embodied in the Estuary SpaTial LandscapE Evolution Model (ESTEEM) code, being developed in the UK as part of the NERC-funded iCOASST project. ESTEEM classifies an estuary into the distinct landform types (subtidal channel, tidal flat, etc), which are then simulated appropriately via one of the approaches highlighted above. Other notable aspects of the model architecture include use of a composite raster and vector data model and compatibility with the OpenMI external coupling standard. The paper describes the contrasting algorithmic approaches and presents illustrative 100-year simulations for a test case estuary.

  13. Population Structure of an Invasive Parthenogenetic Gastropod in Coastal Lakes and Estuaries of Northern KwaZulu-Natal, South Africa

    PubMed Central

    Miranda, Nelson A. F.; Perissinotto, Renzo; Appleton, Christopher C.

    2011-01-01

    Background Estuaries and coastal lakes receive little attention despite being heavily invaded by non-indigenous invasive species (NIS). In these situations, studies of population dynamics in invaded habitats can provide valuable insights into how NIS interact with new environments. Tarebia granifera is a prosobranch gastropod from south-east Asia which has invaded other sub-tropical parts of the world. This study addresses whether a small number of key environmental factors influences gastropod communities, and specifically how the population density and size structure of T. granifera were influenced by environmental change in estuaries and coastal lakes in southern Africa. Methodology/Principal Findings T. granifera's density, number of brooded juveniles and size structure were measured at the St. Lucia Estuary, Mgobozeleni Estuary, Lake Sibaya and Lake Nhlange. Size structure was classified according to shell height (SH). All dissected individuals were found to be female and free from trematode infection. Salinity, water depth, temperature, and pH were the main factors correlated with population density of gastropod communities. T. granifera often reached densities well over 1000 ind. m?2, displacing indigenous gastropods and becoming a dominant component of the benthic community. T. granifera successfully invaded estuaries despite frequent exposure to high salinity and desiccation, which could together eliminate >97% of the population. The persistence of T. granifera was ensured due to its high fecundity and the environmental tolerance of large adults (20–30 mm SH) which carried an average of 158±12.8 SD brooded juveniles. Repeat introductions were not essential for the success of this parthenogenetic NIS. Conclusion/Significance There is a need for a broader study on the reproductive biology of T. granifera (including the previously overlooked “brood pouch ecology”), which affects population dynamics and may be relevant to other parthenogenetic NIS, such as Melanoides tuberculata and Potamopyrgus antipodarum. PMID:21904629

  14. Lawrence Berkeley Laboratory 1994 site environmental report

    SciTech Connect

    1995-05-01

    The 1994 Site Environmental Report summarizes environmental activities at Lawrence Berkeley Laboratory (LBL) for the calendar year (CY) 1994. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the Laboratory`s environmental management programs when measured against regulatory standards and DOE requirements. The report also discusses significant highlight and planning efforts of these programs. The format and content of the report are consistent with the requirements of the U.S. Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

  15. Technology transfer at Lawrence Berkeley Laboratory

    SciTech Connect

    Johnson, D.

    1992-09-01

    Lawrence Berkeley Laboratory (LBL) is dedicated to commercializing new technology in such fields as advanced materials, biotechnology, and electronics. Technology transfer between national laboratories and the industrial community is important in maintaining America's competitive edge. This document examines opportunities to establish working relationships with LBL. Streamlined methods for technology transfer are available with the aid of the Technology Transfer Department and the Patent Department at LBL. Research activities at LBL are concentrated in three major program areas: Energy Sciences, General Sciences, and Biosciences. Each program area consists of three research divisions. LBL welcomes both requests for information and proposals to conduct research.

  16. Technology transfer at Lawrence Berkeley Laboratory

    SciTech Connect

    Johnson, D.

    1992-09-01

    Lawrence Berkeley Laboratory (LBL) is dedicated to commercializing new technology in such fields as advanced materials, biotechnology, and electronics. Technology transfer between national laboratories and the industrial community is important in maintaining America`s competitive edge. This document examines opportunities to establish working relationships with LBL. Streamlined methods for technology transfer are available with the aid of the Technology Transfer Department and the Patent Department at LBL. Research activities at LBL are concentrated in three major program areas: Energy Sciences, General Sciences, and Biosciences. Each program area consists of three research divisions. LBL welcomes both requests for information and proposals to conduct research.

  17. A fully predictive model for salt intrusion in estuaries applied to the Yangtze estuary

    NASA Astrophysics Data System (ADS)

    Cai, Huayang; Savenije, Hubert H. G.; Zuo, Shuhua; Jiang, Chenjuan; Chua, Vivien P.

    2015-04-01

    Understanding the way the salinity distribution in an estuary reacts to external drivers (e.g., tide, fresh water discharge, dredging etc.) is important for both water quality and water resources management in estuaries. The salinity distribution depends strongly on the geometry of an estuary, but also on the fresh water discharge that counteracts the salt intrusion. In estuaries it is notoriously hard to estimate this discharge and subsequently to predict the parameters that determine the mixing behaviour depending on it. Recently a method has been developed to predict the fresh water discharge on the basis of water level observations. In addition predictive equations for tidal mixing have been updated and revised. In this paper, these two predictive methods are combined and subsequently applied to the Yangtze estuary under a wide variation of fresh water discharge. The predicted salt distribution appears to be in good agreement with observations. To provide insight into the optimum use of water resources (e.g., to determine the amount of fresh water discharge required to maintain a specific salt intrusion length), we further studied the salt intrusion pattern under different fresh water discharge conditions.

  18. A predictive model for salt intrusion in estuaries applied to the Yangtze estuary

    NASA Astrophysics Data System (ADS)

    Cai, Huayang; Savenije, Hubert H. G.; Zuo, Shuhua; Jiang, Chenjuan; Chua, Vivien P.

    2015-10-01

    Understanding the way salinity distribution in an estuary reacts to external drivers (e.g., tide, fresh water discharge, dredging, etc.) is important for both water quality and water resources management in estuaries. The salinity distribution depends strongly on the geometry of an estuary, but also on the fresh water discharge that counteracts the salt intrusion. In estuaries it is notoriously hard to estimate this discharge and subsequently to predict the parameters that determine the mixing behaviour depending on it. Recently a method has been developed to predict the fresh water discharge on the basis of water level observations. In addition, predictive equations for tidal mixing have been updated and revised. In this paper, these two predictive methods are combined and subsequently applied to the Yangtze estuary under a wide variation of fresh water discharge. The predicted salt distribution appears to be in good agreement with observations. To provide insight into the optimum use of water resources (e.g., to determine the amount of fresh water discharge required to maintain a specific salt intrusion length), we further study the salt intrusion pattern under different tide and fresh water discharge conditions.

  19. Small estuary, big port - progress in the management of the Stour-Orwell Estuary system

    NASA Astrophysics Data System (ADS)

    Spearman, Jeremy; Baugh, John; Feates, Nigel; Dearnaley, Mike; Eccles, Dan

    2014-10-01

    Management of port development is increasingly challenging because of the competitive requirement for deeper channels and because of the need to preserve important coastal wetlands which function as both habitat and flood defence. This paper describes the management of the Stour/Orwell Estuary system, Eastern England, an estuary system which has experienced considerable development and morphological change. The estuary is internationally important for its wetland bird populations and the intertidal areas of the estuary system are protected under European legislation. It is also the location of the Port of Felixstowe. In 1998/2000 the approach channel to the Port of Felixstowe was deepened from -12.5 mCD to -14.5 mCD. This paper describes the effects of the approach channel deepening, the approach taken to identifying the potential impact to intertidal habitat resulting from the deepening, the sediment recycling implemented as mitigation to prevent increased loss of habitat and the subsequent response of the estuary system to this intervention.

  20. Tidal exchange between a freshwater tidal marsh and an impacted estuary: the Scheldt estuary, Belgium

    NASA Astrophysics Data System (ADS)

    Van Damme, Stefan; Frank, Dehairs; Micky, Tackx; Olivier, Beauchard; Eric, Struyf; Britta, Gribsholt; Oswald, Van Cleemput; Patrick, Meire

    2009-11-01

    Tidal marsh exchange studies are relatively simple tools to investigate the interaction between tidal marshes and estuaries. They have mostly been confined to only a few elements and to saltwater or brackish systems. This study presents mass-balance results of an integrated one year campaign in a freshwater tidal marsh along the Scheldt estuary (Belgium), covering oxygen, nutrients (N, P and Si), carbon, chlorophyll, suspended matter, chloride and sulfate. The role of seepage from the marsh was also investigated. A ranking between the parameters revealed that oxygenation was the strongest effect of the marsh on the estuarine water. Particulate parameters showed overall import. Export of dissolved silica (DSi) was more important than exchange of any other nutrient form. Export of DSi and import of total dissolved nitrogen (DIN) nevertheless contributed about equally to the increase of the Si:N ratio in the seepage water. The marsh had a counteracting effect on the long term trend of nutrient ratios in the estuary.

  1. Pressure safety program Lawrence Livermore National Laboratory

    SciTech Connect

    Borzileri, C.; Traini, M.

    1992-10-01

    The Lawrence Livermore National Laboratory (LLNL) is a Research and Development facility. Programs include research in: nuclear weapons, energy, environmental, biomedical, and other DOE funded programs. LLNL is managed by the University of California for the Department of Energy. Many research and development programs require the use of pressurized fluid systems. In the early 1960`s, courses were developed to train personnel to safely work with pressurized systems. These courses served as a foundation for the Pressure Safety Program. The Pressure Safety Program is administered by the Pressure Safety Manager through the Hazards Control Department, and responsibilities include: (1) Pressure Safety course development and training, (2) Equipment documentation, tracking and inspections/retests, (3) Formal and informal review of pressure systems. The program uses accepted codes and standards and closely follows the DOE Pressure Safety Guidelines Manual. This manual was developed for DOE by Lawrence Livermore National Laboratory. The DOE Pressure Safety Guidelines Manual defines five (5) basic elements which constitute this Pressure Safety Program. These elements are: (1) A Pressure Safety Manual, (2) A Safety Committee, (3) Personnel who are trained and qualified, (4) Documentation and accountability for each pressure vessel or system, (5) Control of the selection and the use of high pressure hardware.

  2. Saving Bays and Estuaries: A primer for establishing and managing Estuary programs. Appendices G, H, and I

    SciTech Connect

    Not Available

    1990-09-01

    The appendix of Saving Bays and Estuaries is: A Primer for Establishing and Managing Estuary Projects. The Primer, which describes the National Estuary Program's origin, statutary provisions, and approach, is designed for EPA's program and Regional offices, coastal States, and other interested parties. For more information, contact an EPA Regional office. Section 320 of the Clean Water Act provides for the development of Comprehensive Conservation and Management Plans (CCMPs) for estuaries of National significance. To ensure the greatest return on resources spent, it is often necessary to document the economic benefits associated with alternative management strategies.

  3. 78 FR 66265 - Drawbridge Operation Regulations; Reynolds Channel, Lawrence, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-05

    ... operations (78 FR 56610) is currently in effect. During ongoing rehabilitation of the bridge the contractor... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Reynolds Channel, Lawrence, NY... operation of the Atlantic Beach Bridge, mile 0.4, across Reynolds Channel, at Lawrence, New York....

  4. 78 FR 34893 - Drawbridge Operation Regulations; Reynolds Channel, Lawrence, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Reynolds Channel, Lawrence, NY... operation of the Atlantic Beach Bridge, mile 0.4, across Reynolds Channel, at Lawrence, New York. This...-9826. SUPPLEMENTARY INFORMATION: The Atlantic Beach Bridge, across Reynolds Channel, mile 0.4,...

  5. 5. Long view of east half of site from Lawrence ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Long view of east half of site from Lawrence General Hospital parking deck (former location of coating mill) showing north side of Clay Storage Silos and northeast block of Wilder Mill; view to southwest. - Champion-International Paper Company, West bank of Spicket River at Canal Street, Lawrence, Essex County, MA

  6. 4. Long view of west half of site from Lawrence ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Long view of west half of site from Lawrence General Hospital parking deck (former location of coating mill) showing north side of rear portion of Wilder Mill and Paper Machine Building; view to southwest. - Champion-International Paper Company, West bank of Spicket River at Canal Street, Lawrence, Essex County, MA

  7. 3. General view of site from Lawrence General Hospital parking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. General view of site from Lawrence General Hospital parking deck (former location of coating mill) showing north side of structures; view to southeast. - Champion-International Paper Company, West bank of Spicket River at Canal Street, Lawrence, Essex County, MA

  8. Measurements of shoaling internal waves and turbulence in an estuary

    E-print Network

    Kelley, Dan

    Measurements of shoaling internal waves and turbulence in an estuary Clark Richards,1 Daniel internal waves may represent an important source of mixing and transport in estuaries and coastal seas of the turbulent energetics, and two main features were studied. First, during a period of shoaling internal waves

  9. PECONIC ESTUARY PROGRAM COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

    EPA Science Inventory

    The Peconic Estuary, situated between the North and South Forks of eastern Long Island, New York, consists of more than 100 distinct bays, harbors, embayments, and tributaries. The area surrounding the Peconic Estuary's watershed is rich in rolling farmland, scenic beaches and cr...

  10. LOWER COLUMBIA RIVER ESTUARY PROGRAM COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

    EPA Science Inventory

    An estuary is the area where the fresh water of a river meets the salt water of an ocean. In the Columbia River system, this occurs in the lower 46 river miles. In an estuary, the river has a direct, natural connection with the open sea. This transition from fresh to salt water c...

  11. YAQUINA BAY AND BEYOND: WHAT SHAPE ARE OUR ESTUARIES IN?

    EPA Science Inventory

    The great natural beauty of Oregon's estuaries gives an impression of systems that are far less altered than those in other areas of the US. However, over the years, Yaquina Bay and other western estuaries have been variously affected by habitat loss and alteration, over harvest...

  12. Trace metal concentrations in estuaries and coastal regions

    SciTech Connect

    Hunt, C.D.

    1994-12-31

    Estuaries and coastal regions are highly variable in the physical and hydrographic conditions. As a result of heavy urbanization and industrialization of the head waters of most estuaries, there are substantial localized inputs of contaminants to the estuary. These factors combined with the flushing characteristics of individual estuaries to create relatively unique features that result in variation in the typical levels of trace metals for these systems. This makes intercomparison of the estuaries difficult. Comparability among estuaries becomes even more difficult when metals analyses are conducted without proper control of field and laboratory contamination, now firmly established in the trace metal analytical literature as a prerequisite for reliable marine trace metals analysis. This paper compares the concentrations of selected trace metal (Ag, Cd, Cu, Ni, Pb, and Zn) concentrations in the waters of several major estuaries of the United States. The basis of comparison is that all samples war collected under rigid trace metal clean collection and analysis procedures. Generally, metal concentrations within the estuaries are similar. Metal concentrations in the higher salinity coastal regions are more similar in concentration. The comparison provides a baseline of typical concentrations of these trace metals in the coastal waters against which future analytical results can be compared.

  13. Macroalgae, pore water sulfides and eelgrass in Yaquina estuary, Oregon

    EPA Science Inventory

    The hypothesis that relatively high nutrients in estuaries of the Pacific Northwest (PNW) can lead to eutrophication and degradation of critical eelgrass habitat was examined. Yaquina estuary was surveyed for cover and above-ground biomass of benthic macroalgae (Ulva spp.) and n...

  14. Nitrogen Source and Loading Data for EPA Estuary Data Mapper

    EPA Science Inventory

    Nitrogen source and loading data have been compiled and aggregated at the scale of estuaries and associated watersheds of the conterminous United States, using the spatial framework in EPA's Estuary Data Mapper (EDM) to provide system boundaries. Original sources of data include...

  15. FOOD PATHWAYS ASSOCIATED WITH PENAEID SHRIMPS IN A MANGROVEFRINGED ESTUARY

    E-print Network

    FOOD PATHWAYS ASSOCIATED WITH PENAEID SHRIMPS IN A MANGROVE·FRINGED ESTUARY ALLAN W. STONERl AND Ro estuaries has been attributed to high concentrations of mangrove-derived detritus in the nursery habitats. Examination of the diets ofPII7UUl'UIl noOO/is, P. subti/is, and P. braBiliensis in the mangrove

  16. WATER QUALITY MODELING IN THE RIO CHONE ESTUARY

    EPA Science Inventory

    Water quality in the Rio Chone Estuary, a seasonally inverse, tropical estuary, in Ecuador was characterized by modeling the distribution of biochemical oxygen demand (BOD) and dissolved inorganic nitrogen (DIN) within the water column. These two variables are modeled using modif...

  17. INDEX OF ESTUARINE BENTHIC INTEGRITY FOR GULF OF MEXICO ESTUARIES

    EPA Science Inventory

    A benthic index for northern Gulf of Mexico estuaries has been developed and successfully validated by the Environmental Monitoring and Assessment Program for Estuaries (EMAP-E) in the Louisianian Province. The benthic index is a useful indicator of estuarine condition that provi...

  18. ASSESSING THE ECOLOGICAL CONDITION OF SOUTHEAST U. S. ESTUARIES

    EPA Science Inventory

    As a means to assess ecological condition, 151 stations located in southeastern estuaries from Cape Henry, Virginia to Biscayne Bay, Florida were sampled by state agencies during the summer of 2000 using a probabilistic design. The design used 8 size classes of estuaries ranging ...

  19. NAME: Port Susan Bay Estuary Restoration LOCATION: Snohomish County, Washington

    E-print Network

    US Army Corps of Engineers

    Restoration Project proposes to reintroduce the full tidal prism and inundation regime to 150 acres of diked farmland in the Stillaguamish River estuary in Puget Sound. In doing this, self sustaining native tidal in the northeastern portion of Port Susan Bay will be increased. This project will restore estuary-scale sediment

  20. St. Petersburg Electrotechnical University " LETI" Prof. Popov st. 5, St. Petersburg, 197376, Russia

    E-print Network

    Nejdl, Wolfgang

    , Russia International Summer School @ ETU "LETI" St. Petersburg Electrotechnical University 4 MODULS Electrotechnical University " LETI" Prof. Popov st. 5, St. Petersburg, 197376, Russia International Summer School

  1. Public attitudes toward Lawrence Livermore National Laboratory

    SciTech Connect

    Not Available

    1990-05-01

    Charlton Research Company is pleased to present the following summary of findings report for research conducted under contract with Lawrence Livermore National Laboratory. This section provides a brief introduction to the specifications of the study, and a guide to the organization of this report. Although the most sophisticated procedures have been used to collect and analyze the information presented here, it must be remembered that qualitative and quantitative research are not predictions. They are designed to measure public opinion within identifiable statistical limits or accuracy at specific points in time. This research is in no way a prediction of opinion or action at any future point in time. Among the topics covered in the surveys are: openness; National Laboratory; health hazards; radioactivity; uses of plutonium; hazardous waste; groundwater pollution; nuclear weapons; Ballistic Missile Defense; and earthquakes.

  2. Adaptive Optics at Lawrence Livermore National Laboratory

    SciTech Connect

    Gavel, D T

    2003-03-10

    Adaptive optics enables high resolution imaging through the atmospheric by correcting for the turbulent air's aberrations to the light waves passing through it. The Lawrence Livermore National Laboratory for a number of years has been at the forefront of applying adaptive optics technology to astronomy on the world's largest astronomical telescopes, in particular at the Keck 10-meter telescope on Mauna Kea, Hawaii. The technology includes the development of high-speed electrically driven deformable mirrors, high-speed low-noise CCD sensors, and real-time wavefront reconstruction and control hardware. Adaptive optics finds applications in many other areas where light beams pass through aberrating media and must be corrected to maintain diffraction-limited performance. We describe systems and results in astronomy, medicine (vision science), and horizontal path imaging, all active programs in our group.

  3. Lawrence Berkeley Laboratory Affirmative Action Program. Revised

    SciTech Connect

    1995-06-01

    The Lawrence Berkeley Laboratory`s Affirmative Action Program (AAP) serves as a working document that describes current policies, practices, and results in the area of affirmative action. It represents the Laboratory`s framework for an affirmative approach to increasing the representation of people of color and women in segments of our work force where they have been underrepresented and taking action to increase the employment of persons with disabilities and special disabled and Vietnam era veterans. The AAP describes the hierarchy of responsibility for Laboratory affirmative action, the mechanisms that exist for full Laboratory participation in the AAP, the policies and procedures governing recruitment at all levels, the Laboratory`s plan for monitoring, reporting, and evaluating affirmative action progress, and a description of special affirmative action programs and plans the Laboratory has used and will use in its efforts to increase the representation and retention of groups historically underrepresented in our work force.

  4. St. John's Wort (image)

    MedlinePLUS

    The herb St. John's Wort is believed to be helpful in relieving mild to moderate depression, but should only be taken under a physician's supervision. St. John's Wort may clash with other medications or foods ...

  5. PECONIC ESTUARY: RECREATIONAL AND RESOURCE ECONOMIC VALUES FOR THE PECONIC ESTUARY SYSTEM

    EPA Science Inventory

    The environmental and natural resources ("natural assets") of the Peconic Estuary System--the bay waters, beaches, wetlands, ecosystems, habitats, and parks and watershed lands--provide many services to the public. Outdoor recreation, scenic views, and the productivity of wetland...

  6. Approaches for Development of Nutrient Criteria in Oregon Estuaries With a Focus on Tillamook Estuary

    EPA Science Inventory

    Development of nutrient criteria for all water body types of the US remains a top priority for EPA. Estuaries in the Pacific Northwest receive nutrients from both the watershed and the coastal ocean, and thus are particularly complex systems in which to establish water quality c...

  7. 1322004 Estuarine Research Federation Estuaries Vol. 27, No. 1, p. 132146 February 2004

    E-print Network

    North, Elizabeth W.

    1322004 Estuarine Research Federation Estuaries Vol. 27, No. 1, p. 132­146 February 2004 to a straight-channel estuary and enhanced with sediment transport, erosion, deposition, and burial components and wind. Although increases and decreases in river flow caused down- estuary and up-estuary (respectively

  8. Optimal Migration Routes of Dusky Canada Geese: Can They Indicate Estuaries in British Columbia

    E-print Network

    Optimal Migration Routes of Dusky Canada Geese: Can They Indicate Estuaries in British Columbia Routes of Dusky Canada Geese: Can They Indicate Estuaries in British Columbia for Conservation? Project threats, habitat loss, and degradation of British Columbian (BC) estuaries, the Pacific Estuary

  9. Thank you to our sponsors Thinking about healthy estuaries in the Year 2111 and

    E-print Network

    #12;Thank you to our sponsors #12;Thinking about healthy estuaries in the Year 2111 and assuming support and resources: What is your vision of what an estuary should look like? Think about: What do you value in an estuary? How do you use estuaries? #12;Why

  10. Continental Shelf Research 29 (2009) 136147 Initial growth of phytoplankton in turbid estuaries: A simple model

    E-print Network

    Horner-Devine, Alex

    2009-01-01

    Continental Shelf Research 29 (2009) 136­147 Initial growth of phytoplankton in turbid estuaries the dynamics of phytoplankton blooms in well-mixed, suspended sediment dominated estuaries. The model describes problem. The growth rates depend on the position in the estuary due to along-estuary variations

  11. AN APPROACH TO DEVELOPING NUTRIENT CRITERIA FOR PACIFIC NORTHWEST ESTUARIES: A CASE STUDY OF YAQUINA ESTUARY, OREGON

    EPA Science Inventory

    NHEERL scientists have developed an approach that could be used by the State of Oregon for development of nutrient and other water quality criteria for the Yaquina Estuary, Oregon. The principle objective in setting protective criteria is to prevent future degradation of estuari...

  12. PECONIC ESTUARY: AN INVENTORY OF SUBMERGED AQUATIC VEGETATION AND HARDENED SHORELINES FOR THE PECONIC ESTUARY, NEW YORK

    EPA Science Inventory

    Executive Summary The Peconic Estuary Program (PEP) is interested in the extent of eelgrass and other submerged aquatic vegetation and in documenting changes in the shorelines of the Peconic Estuary. The Suffolk County Department of Health Services' Office of Ecology provided fun...

  13. Global patterns and predictors of fish species richness in estuaries.

    PubMed

    Vasconcelos, Rita P; Henriques, Sofia; França, Susana; Pasquaud, Stéphanie; Cardoso, Inês; Laborde, Marina; Cabral, Henrique N

    2015-09-01

    1. Knowledge of global patterns of biodiversity and regulating variables is indispensable to develop predictive models. 2. The present study used predictive modelling approaches to investigate hypotheses that explain the variation in fish species richness between estuaries over a worldwide spatial extent. Ultimately, such models will allow assessment of future changes in ecosystem structure and function as a result of environmental changes. 3. A comprehensive worldwide data base was compiled of the fish assemblage composition and environmental characteristics of estuaries. Generalized Linear Models were used to quantify how variation in species richness among estuaries is related to historical events, energy dynamics and ecosystem characteristics, while controlling for sampling effects. 4. At the global extent, species richness differed among marine biogeographic realms and continents and increased with mean sea surface temperature, terrestrial net primary productivity and the stability of connectivity with a marine ecosystem (open vs. temporarily open estuaries). At a smaller extent (within a marine biogeographic realm or continent), other characteristics were also important in predicting variation in species richness, with species richness increasing with estuary area and continental shelf width. 5. The results suggest that species richness in an estuary is defined by predictors that are spatially hierarchical. Over the largest spatial extents, species richness is influenced by the broader distributions and habitat use patterns of marine and freshwater species that can colonize estuaries, which are in turn governed by history contingency, energy dynamics and productivity variables. Species richness is also influenced by more regional and local parameters that can further affect the process of community colonization in an estuary including the connectivity of the estuary with the adjacent marine habitat, and, over smaller spatial extents, the size of these habitats. In summary, patterns of species richness in estuaries across large spatial extents seem to reflect from global to local processes acting on community colonization. The importance of considering spatial extent, sampling effects and of combining history and contemporary environmental characteristics when exploring biodiversity is highlighted. PMID:25788236

  14. Missouri: St. Louis

    Atmospheric Science Data Center

    2014-05-15

    article title:  St. Louis, Missouri     View Larger Image St. Louis is tucked in a bend of the Mississippi River, just south of the point at ... camera on October 15, 2005. The urban areas of greater St. Louis show up as grey-white, including nearby Kirkwood, Webster Groves, ...

  15. Final report for sea-level rise response modeling for San Francisco Bay estuary tidal marshes

    USGS Publications Warehouse

    Takekawa, John Y.; Thorne, Karen M.; Buffington, Kevin J.; Spragens, Kyle A.; Swanson, Kathleen M.; Drexler, Judith Z.; Schoellhamer, David H.; Overton, Cory T.; Casazza, Michael L.

    2013-01-01

    The International Panel on Climate Change has identified coastal ecosystems as areas that will be disproportionally affected by climate change. Current sea-level rise projections range widely with 0.57 to 1.9 meters increase in mea sea level by 2100. The expected accelerated rate of sea-level rise through the 21st century will put many coastal ecosystems at risk, especially those in topographically low-gradient areas. We assessed marsh accretion and plant community state changes through 2100 at 12 tidal salt marshes around San Francisco Bay estuary with a sea-level rise response model. Detailed ground elevation, vegetation, and water level data were collected at all sites between 2008 and 2011 and used as model inputs. Sediment cores (taken by Callaway and others, 2012) at four sites around San Francisco Bay estuary were used to estimate accretion rates. A modification of the Callaway and others (1996) model, the Wetland Accretion Rate Model for Ecosystem Resilience (WARMER), was utilized to run sea-level rise response models for all sites. With a mean sea level rise of 1.24 m by 2100, WARMER projected that the vast majority, 95.8 percent (1,942 hectares), of marsh area in our study will lose marsh plant communities by 2100 and to transition to a relative elevation range consistent with mudflat habitat. Three marshes were projected to maintain marsh vegetation to 2100, but they only composed 4.2 percent (85 hectares) of the total marsh area surveyed.

  16. Phosphorous dynamics in a temperate intertidal estuary

    NASA Astrophysics Data System (ADS)

    Lillebø, A. I.; Neto, J. M.; Flindt, M. R.; Marques, J. C.; Pardal, M. A.

    2004-09-01

    Conservation and management of aquatic systems require detailed information of the processes that affect their functioning and development. The objectives of the present work were to describe the phosphorus dynamics during a complete tidal cycle and to quantify the relative contribution of the most common estuarine areas (e.g. seagrass beds, salt marshes, mud- and sand-flats without vegetation) to phosphorus net internal loading in a temperate intertidal estuary. Results show that phosphate efflux rates were higher during the first hours of tidal flood, and that phosphate concentrations were lowest at high tide. During tidal ebbing, ephemeral tide pools may cover a considerable percentage of the intertidal area. In these tide pools, water shallowness combined with enhanced temperatures stimulate the occurrence of high phosphate effluxes. The effluxes to the main water body during high tide contributed 57% of dissolved inorganic phosphorus and efflux during low tide contributed 43% to the net internal loading. Calculations of the phosphate net effluxes (kg P) indicate a strong contribution of the bare bottom mud-flats to the whole system internal phosphate loading, especially during the warmer periods. As a consequence of eutrophication, perennial benthic macrophytes are commonly replaced by fast-growing epiphytic macroalgae. Calculations showed that for a hypothetical intertidal estuary in a temperate region, management programs considering an eventual re-colonization of mud-flats by seagrasses or salt marsh plants may reduce the P-efflux by 13-16 kg ha -1. For example, in the small Mondego estuary, eutrophication has contributed to a reduction of the Zostera noltii meadows, leading to an increase in 190 kg of phosphorus net internal loading.

  17. Near coastal program plan for 1991: Estuaries

    SciTech Connect

    Not Available

    1990-11-01

    Environmental regulatory programs in the United States have been estimated to cost more than $70 billion annually. The Environmental Monitoring and Assessment Program (EMAP) is a nationwide initiative being implemented by EPA's Office of Research and Development (ORD). It was developed in response to the demand for information on the condition of the nation's ecological resources. The goal of EMAP is to assess and document the status and trends in the condition of the nation's forests, wetlands, estuaries, coastal waters, lakes, rivers, and streams, Great Lakes, agricultural lands, and arid lands on an integrated and continuing basis.

  18. Synthesis and Modelling of Intermittent Estuaries

    NASA Astrophysics Data System (ADS)

    Kjerfve, Bjürn

    Port Hacking is a small subtropical estuary, relatively unpolluted despite its location only 30 km south of Sydney on Australia's Pacific coast. It was the site of a 5-year (1973-1978) multidisciplinary ecosystem project, focusing on the flow of carbon into, within, and out of the estuarine system. The ultimate goal of the project was the formulation and implementation of a predictive model of the carbon dynamics. However, this book, which summarizes the project, reports that the scientific team failed in its effort to reach the goal of a predictive model.

  19. Polychlorinated biphenyl residues in some marine organisms from the Baie des Anglais (Baie-Comeau, Quebec, Saint-Lawrence Estuary

    SciTech Connect

    Delval, C.; Fournier, S.; Vigneault, Y.

    1986-12-01

    The main source of PCB's in the Baie des Anglais comes from a pseudo lagoon which is located upstream from the Anse au Moulin immediately below an aluminum plant. Organic matter in suspension coming from industrial wastes from baie-Comeau is likely responsible for the binding of PCB's. However due to hydrodynamic factors in the Baie des Anglais, contaminants stay only a short time in the littoral area and are evacuated to the southeast, where they accumulate at 80 m depth. Another source of contamination is the accumulation of dredging spoils at the entrance of the Anse au Moulin above the 40 m isobath. The contaminated sediments are resuspended by storm wave action. The work described in this paper was conducted in order to determine the extent of PCB bioaccumulation in two molluscs species (Mytilus edulis L. and Buccinum undatum L.) and two fish species (Clupea harengus harengus and Anguilla rostrata) from the Baie des Anglais (Baie-Comeau, Quebec).

  20. Magnitude and extent of sediment toxicity in selected estuaries of South Carolina and Georgia. Technical memo

    SciTech Connect

    Long, E.R.; Scott, G.I.; Kucklick, J.; Fulton, M.; Thompson, B.

    1998-04-01

    Surficial sediment samples were collected from 162 locations within five estuaries -- Charleston Harbor, Winyah Bay, Leadenwah Creek, Savannah River, and St. Simons Sound -- in coastal South Carolina and Georgia in a survey of sediment toxicity performed in 1993 and 1994. All samples were tested for toxicity with a battery of complimentary laboratory bioassays. The laboratory bioassays consisted of amphipod survival tests in solid-phase sediments, microbial bioluminescence (Microtox{trademark}) tests of organic solvent extracts, and sea urchin fertilization and embryo development tests of porewaters. Some samples also were tested in copepod reproduction and cytochrome P-450 RGS bioassays. Chemical analyses for a suite of trace metals, organic compounds, and sedimentological factors were performed with portions of most samples.

  1. Sources of Heavy Metal Pollution into the St. Louis River, Lake Superior Watershed

    NASA Astrophysics Data System (ADS)

    Sternberg, S. P.; Palokangas, C.

    2013-12-01

    The St. Louis River begins in Hoyt Lakes, Minnesota and enters Lake Superior between Duluth, Minnesota and Superior, Wisconsin. The Partridge River and the Embarrass River are two of its main tributaries. National Pollutant Discharge Elimination System (NPDES) permits are issued for surface water dischargers under the Clean Water Act. The Permit Compliance System (PCS) and the Integrated Compliance Information System (ICIS) is a tool allowing public access to information contained in NPDES permits. Along the way to Lake Superior, 19 facilities list the St. Louis River, St. Louis Bay, part of the St. Louis River estuary, or one of its tributaries as a receiving water. Of these 19 locations, four report discharging heavy metals into the receiving water. Copper and Lead are the metals most frequently discharged.

  2. Scavenging Rate Ecoassay: A Potential Indicator of Estuary Condition

    PubMed Central

    Porter, Augustine G.; Scanes, Peter R.

    2015-01-01

    Monitoring of estuary condition is essential due to the highly productive and often intensely impacted nature of these ecosystems. Assessment of the physico-chemical condition of estuaries is expensive and difficult due to naturally fluctuating water quality and biota. Assessing the vigour of ecosystem processes is an alternative method with potential to overcome much of the variability associated with physico-chemical measures. Indicators of estuary condition should have small spatial and temporal variability, have a predictable response to perturbation and be ecologically relevant. Here, we present tests of the first criterion, the spatio-temporal variability of a potential ecoassay measuring the rate of scavenging in estuaries. We hypothesised that the proposed scavenging ecoassay would not vary significantly among A) sites in an estuary, B) trips separated by weeks, or C) days in a trip. Because not all habitats are present in all estuaries, this test was undertaken in two habitats. When conducted over bare substrate there were occasional significant differences, but no discernible patterns, within levels of the experiment. When conducted over vegetated substrate, days within a trip did not vary significantly, but later trips experienced greater scavenging. This scavenging ecoassay shows potential as a tool for assessing the condition of estuarine ecosystems, and further exploration of this protocol is warranted by implementation in estuaries across a gradient of anthropogenic stress. PMID:26024225

  3. Geographic signatures of North American West Coast estuaries

    USGS Publications Warehouse

    Emmett, Robert; Llansó, Roberto; Newton, Jan; Thom, Ron; Hornberger, Michelle; Morgan, Cheryl; Levings, Colin; Copping, Andrea; Fishman, Paul

    2000-01-01

    West Coast estuaries are geologically young and composed of a variety of geomorphological types. These estuaries range from large fjords to shallow lagoons; from large to low freshwater flows. Natural hazards include E1 Niños, strong Pacific storms, and active tectonic activity. West Coast estuaries support a wide range of living resources: five salmon species, harvestable shellfish, waterfowl and marine birds, marine mammals, and a variety of algae and plants. Although populations of many of these living resources have declined (salmonids), others have increased (marine mammals). West Coast estuaries are also centers of commerce and increasingly large shipping traffic. The West Coast human population is rising faster than most other areas of the U.S. and Canada, and is distributed heavily in southern California, the San Francisco Bay area, around Puget Sound, and the Fraser River estuary. While water pollution is a problem in many of the urbanized estuaries, most estuaries do not suffer from poor water quality. Primary estuarine problems include habitat alterations, degradation, and loss; diverted freshwater flows; marine sediment contamination; and exotic species introductions. The growing West Coast economy and population are in part related to the quality of life, which is dependent on the use and enjoyment of abundant coastal natural resources.

  4. Lawrence Berkeley National Laboratory A Local-View Array

    E-print Network

    California at Berkeley, University of

    Space C++ Programs Amir Kamil, Yili Zheng, and Katherine Yelick Lawrence Berkeley Lab Berkeley, CA, USA for each timestep: // Copy ghost zones from previous timestep. for (int j = 0; j j++) allA[neighbors[j

  5. Annual environmental monitoring report of the Lawrence Berkeley Laboratory, 1980

    SciTech Connect

    Schleimer, G.E.

    1981-04-01

    The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data on air and water sampling and continuous radiation monitoring for 1980 are presented, and general trends are discussed.

  6. Poisson Compound and Empirical Bayes Estimation, Revisited1 Lawrence Brown

    E-print Network

    Brown, Lawrence D.

    . The approach we take is consistent with Robbins original empirical Bayes proposal. Write 1 Poisson Compound and Empirical Bayes Estimation, Revisited1 Lawrence investigate a classical non-parametric Poisson empirical Bayes estimation problem

  7. Lawrence Livermore National Laboratory Environmental Report 2010

    SciTech Connect

    Jones, H E; Bertoldo, N A; Campbell, C G; Cerruti, S J; Coty, J D; Dibley, V R; Doman, J L; Grayson, A R; MacQueen, D H; Wegrecki, A M; Armstrong, D H; Brigdon, S L; Heidecker, K R; Hollister, R K; Khan, H N; Lee, G S; Nelson, J C; Paterson, L E; Salvo, V J; Schwartz, W W; Terusaki, S H; Wilson, K R; Woods, J M; Yimbo, P O; Gallegos, G M; Terrill, A A; Revelli, M A; Rosene, C A; Blake, R G; Woollett, J S; Kumamoto, G

    2011-09-14

    The purposes of the Lawrence Livermore National Laboratory Environmental Report 2010 are to record Lawrence Livermore National Laboratory's (LLNL's) compliance with environmental standards and requirements, describe LLNL's environmental protection and remediation programs, and present the results of environmental monitoring at the two LLNL sites - the Livermore site and Site 300. The report is prepared for the U.S. Department of Energy (DOE) by LLNL's Environmental Protection Department. Submittal of the report satisfies requirements under DOE Order 231.1A, Environmental Safety and Health Reporting, and DOE Order 5400.5, Radiation Protection of the Public and Environment. The report is distributed electronically and is available at https://saer.llnl.gov/, the website for the LLNL annual environmental report. Previous LLNL annual environmental reports beginning in 1994 are also on the website. Some references in the electronic report text are underlined, which indicates that they are clickable links. Clicking on one of these links will open the related document, data workbook, or website that it refers to. The report begins with an executive summary, which provides the purpose of the report and an overview of LLNL's compliance and monitoring results. The first three chapters provide background information: Chapter 1 is an overview of the location, meteorology, and hydrogeology of the two LLNL sites; Chapter 2 is a summary of LLNL's compliance with environmental regulations; and Chapter 3 is a description of LLNL's environmental programs with an emphasis on the Environmental Management System including pollution prevention. The majority of the report covers LLNL's environmental monitoring programs and monitoring data for 2010: effluent and ambient air (Chapter 4); waters, including wastewater, storm water runoff, surface water, rain, and groundwater (Chapter 5); and terrestrial, including soil, sediment, vegetation, foodstuff, ambient radiation, and special status wildlife and plants (Chapter 6). Complete monitoring data, which are summarized in the body of the report, are provided in Appendix A. The remaining three chapters discuss the radiological impact on the public from LLNL operations (Chapter 7), LLNL's groundwater remediation program (Chapter 8), and quality assurance for the environmental monitoring programs (Chapter 9). The report uses System International units, consistent with the federal Metric Conversion Act of 1975 and Executive Order 12770, Metric Usage in Federal Government Programs (1991). For ease of comparison to environmental reports issued prior to 1991, dose values and many radiological measurements are given in both metric and U.S. customary units. A conversion table is provided in the glossary.

  8. Annual environmental monitoring report of the Lawrence Berkeley Laboratory

    SciTech Connect

    Schleimer, G.E.; Pauer, R.O.

    1990-08-01

    The Lawrence Berkeley Laboratory (LBL) is a multiprogram national laboratory managed by the University of California (UC) for the US Department of Energy (DOE). LBL's major role is to conduct basic and applied science research that is appropriate for an energy research laboratory. The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data for 1989 are presented, and general trends are discussed. 17 refs., 12 figs., 23 tabs.

  9. Astronauts Lawrence and Gregory debrief each other before new shift

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Astronauts Wendy B. Lawrence and William G. Gregory debrief each other on the flight deck of the Earth orbiting Space Shuttle Endeavour during the STS-67 mission. Lawrence, mission specialist and flight engineer, served as the pilot on the blue shift and Gregory filled that position for the red shift. The two, along with Stephen S. Oswald, mission commander, provided round-the-clock support to the ASTRO-2 payload's timelines, performing maneuvers to put Endeavour in the proper attitudes for onboard experiments.

  10. STS-67 Flight Engineer Wendy Lawrence Suites Up

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In the Operations and Checkout Building, STS-67 Mission Specialist and Flight Engineer Wendy B. Lawrence is donning her launch/entry suit with assistance from a suit technician. Lawrence -- who is about to make her first trip into space -- and six fellow crew members will soon depart for Launch Pad 39A, where the Space Shuttle Endeavour is being readied for liftoff during a launch window opening at 1:37 a.m. EST, March 2.

  11. Vulnerability Assessments in Support of the Climate Ready Estuaries Program: A Novel Approach Using Expert Judgment, Volume I: Results for the San Francisco Estuary Partnership (Final Report)

    EPA Science Inventory

    Cover of the San Francisco <span class=Estuary Partnership Climate Ready Estuaries Program Final Report"> As part of the Climate Ready Estuaries (CRE) pr...

  12. Use of the USEPA Estuary Nitrogen Model to Estimate Concentrations of Total Nitrogen in Estuaries Using Loads Calculated by Watershed Models and Monitoring Data

    EPA Science Inventory

    We use USEPA’s Estuary Nitrogen Model (ENM) to calculate annual average concentrations of total nitrogen (TN) in ten estuaries or sub-estuaries along the Atlantic coast from New Hampshire to Florida. These include a variety of systems, ranging from strongly-flushed bays to weakly...

  13. Radiation-induced carcinoma of the lung--the St. Lawrence tragedy.

    PubMed

    Wright, E S; Couves, C M

    1977-10-01

    This paper reviews the problem of radiation-induced carcinoma of the lung in the fluorspar mines of Newfoundland. Seventy-eight workers have died from this disease since commercial operation commenced in 1933. In 1959 the source of the radiation was identified as radon, and its daughter nucleotides present as contaminants in water seeping into the mines. Heavy smoking is probably a synergistic cocarcinogen. The histology in this group of patients with radiation-induced lung cancers is unusual, since squamous cell carcinoma accounts for 90 percent of all cases. There have been four patients with second primary lung cancers. Radical radiotherapy has been the primary mode of treatment based on the reluctance of the miners to undergo operation. Surprisingly good results have been obtained, with an average survival time of 34 months after treatment. Institution of improved ventilation has reduced radiation to safe levels, but an estimated 120 miners from the pre-1960 era are still at risk. PMID:904348

  14. POTASSIC MAGMATISM ON ST. LAWRENCE ISLAND, ALASKA, AND CAPE DEZHNEV, NORTHEAST RUSSIA

    E-print Network

    Amato, Jeff

    a syenite pluton at Cape Dezhnev on the Chukotka Peninsula of Russia. These geochemical data are used of larger-volume subalkaline magmatism between 110 and 100 Ma (and possibly younger). A nepheline syenite but less potassic than the syenites. It has Nd of -0.35 and initial 87Sr/86Sr of 0.7063, and a biotite from

  15. Optical dating of St. Lawrence Iroquoian ceramics from the Mailhot-Curran site, southern Quebec

    E-print Network

    periods (Fig. S1) are characterized by a mobile hunter- gatherers lifestyle. From the archaeological, the transition to a sedentary life- style is slow and gradual (Chapdelaine, 1993). The Mailhot-Curran site. The economy of this commu- nity is centred on horticulture exploitation, hunting, fishing and gathering

  16. Marine Mammal Strandings and Environmental Changes: A 15-Year Study in the St. Lawrence Ecosystem

    PubMed Central

    Truchon, Marie-Hélène; Measures, Lena; L’Hérault, Vincent; Brêthes, Jean-Claude; Galbraith, Peter S.; Harvey, Michel; Lessard, Sylvie; Starr, Michel; Lecomte, Nicolas

    2013-01-01

    Understanding the effects of climatic variability on marine mammals is challenging due to the complexity of ecological interactions. We used general linear models to analyze a 15-year database documenting marine mammal strandings (1994–2008; n?=?1,193) and nine environmental parameters known to affect marine mammal survival, from regional (sea ice) to continental scales (North Atlantic Oscillation, NAO). Stranding events were more frequent during summer and fall than other seasons, and have increased since 1994. Poor ice conditions observed during the same period may have affected marine mammals either directly, by modulating the availability of habitat for feeding and breeding activities, or indirectly, through changes in water conditions and marine productivity (krill abundance). For most species (75%, n?=?6 species), a low volume of ice was correlated with increasing frequency of stranding events (e.g. R2adj?=?0.59, hooded seal, Cystophora cristata). This likely led to an increase in seal mortality during the breeding period, but also to increase habitat availability for seasonal migratory cetaceans using ice-free areas during winter. We also detected a high frequency of stranding events for mysticete species (minke whale, Balaenoptera acutorostrata) and resident species (beluga, Delphinapterus leucas), correlated with low krill abundance since 1994. Positive NAO indices were positively correlated with high frequencies of stranding events for resident and seasonal migratory cetaceans, as well as rare species (R2adj?=?0.53, 0.81 and 0.34, respectively). This contrasts with seal mass stranding numbers, which were negatively correlated with a positive NAO index. In addition, an unusual multiple species mortality event (n?=?114, 62% of total annual mortality) in 2008 was caused by a harmful algal bloom. Our findings provide an empirical baseline in understanding marine mammal survival when faced with climatic variability. This is a promising step in integrating stranding records to monitor the consequences of environmental changes in marine ecosystems over long time scales. PMID:23544059

  17. 137Cs and 210Po in Pacific walrus and bearded seal from St. Lawrence Island, Alaska.

    PubMed

    Hamilton, Terry; Seagars, Dana; Jokela, Terry; Layton, David

    2008-06-01

    The activity concentration of Cesium-137 ((137)Cs) and naturally-occurring Polonium-210 ((210)Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea during May 1996. The mean (137)Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg(-1) (n=5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg(-1) (n=2, wet weight), respectively, in bearded seal. In general, (137)Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, (210)Po activity concentrations are more variable and appear to be higher level compared with mammal data from other regions. The mean (210)Po concentration in the muscle tissue, liver and kidney of Pacific walrus (n=5, wet weight) were 28.7, 189, and 174 Bq kg(-1), respectively. This compares with (210)Po concentration values (n=2, wet weight) of 27, 207 and 68 Bq kg(-1) measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated concentration factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for (210)Po that those of (137)Cs. We conclude from radiological dose estimates that ingestion of (137)Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessment of risks of Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic. PMID:18371988

  18. Citizens' Guide to Biomonitoring in the Great Lakes and St. Lawrence River.

    ERIC Educational Resources Information Center

    Great Lakes United, Buffalo, NY.

    The purpose of this report is to present the issues surrounding biomonitoring of wastewaters discharged into the Great Lakes Basin. Biomonitoring is the process of using organisms to monitor the toxicity of a substance. The report reflects an interest in seeing zero discharge of toxic pollutants in the Great Lakes region. The report is organized…

  19. Water resources data, Ohio: Water year 1991. Volume 2, St. Lawrence River Basin: Statewide project data

    SciTech Connect

    Shindel, H.L.; Klingler, J.H.; Mangus, J.P.; Trimble, L.E.

    1992-03-01

    The Water Resources Division of the US Geological Survey (USGS), in cooperation with State agencies, obtains a large amount of data pertaining to the water resources of Ohio each water year. These data, accumulated during many years, constitute a valuable data base for developing an improved understanding of the water resources of the State. To make these data readily available to interested parties outside the USGS, the data are published annually in this report series entitled ``Water Resources Data--Ohio.`` This report (in two volumes) includes records on surface water and ground water in the State. Specifically, it contains: (1) Discharge records for 131 streamflow-gaging stations, 95 miscellaneous sites; (2) stage and content records for 5 streams, lakes, and reservoirs; (3) water-quality for 40 streamflow-gaging stations, 378 wells, and 74 partial-record sites; and (4) water levels for 431 observation wells.

  20. 77 FR 42642 - Safety Zone; City of Ogdensburg Fireworks, St. Lawrence River, Ogdensburg, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    .... SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice... Christopher Mercurio, Chief of Waterways Management, U.S. Coast Guard Sector Buffalo; telephone 716- 843-9343, email SectorBuffaloMarineSafety@uscg.mil . If you have questions on viewing or submitting material...

  1. Shoreline retreat and coastal storms in the southern Gulf of St. Lawrence

    NASA Astrophysics Data System (ADS)

    Forbes, D. L.; Parkes, G.; Manson, G. K.; Ketch, L.; Solomon, S. M.

    2001-05-01

    Submerged fluvial channels and estuarine facies seaward of the sandy North Shore of Prince Edward Island (Canada) attest to long-term mean relative sea-level rise >2.5 mm/a driving coastal retreat at mean rates >0.5 m/a over the past six thousand years. The shoreface, nearshore multiple bar complexes, and beaches are sand-limited and sand is transferred landward into multidecadal to century-scale storage in coastal dune and flood-tidal delta sinks. Stringent quality control of tide-gauge records for Charlottetown (PEI) indicates mean relative sea-level rise of 3.2 mm/a since 1911. When differenced from tidal predictions, this record provides a decadal sequence of storm surge occurrence for comparison with wind, wave hindcast, and sea-ice data for the southern Gulf over the past several decades. Soft photogrammetric digital rectification of vertical air photographs (1935, 1958, 1968, 1980/1981, 1990) and ground surveys (1989-2001) show large spatial and temporal variance in coastal recession rates, poorly correlated with the overall storm record, in part because of wave suppression by sea ice. Retreat of low sandstone-till cliffs at <1 m/a shows no statistically significant decadal variance. Other sites with shoreline retreat rates typically between 0.5 and 1.5 m/a show localized acceleration after 1980, reflecting a combination of storm impacts, morphodynamic change and sand loss to adjacent tidal inlets. Individual large storms cause localized rapid erosion, from which recovery depends in part on local sand supply. Some barrier shores with dunes show high longshore and interdecadal variance, and extensive multidecadal healing of former inlet and washover gaps. In some areas, at least, this reflects recovery from an episode of widespread washover predating the 1935 photography.

  2. 137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

    SciTech Connect

    Hamilton, T F; Seagars, D J; Jokela, T; Layton, D

    2005-02-02

    The activity concentration of Cesium-137 ({sup 137}Cs) and naturally-occurring Polonium-210 ({sup 210}Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea. The mean {sup 137}Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg{sup -1} (N= 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg{sup -1} (N=2, wet weight), respectively, in bearded seal. In general, {sup 137}Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, {sup 210}Po activity concentrations appear to be higher than those reported elsewhere but a larger variation. The mean {sup 210}Po concentration in the muscle tissue, liver and kidney of Pacific walrus (N=5, wet weight) were 28.7, 189, and 174 Bq kg{sup -1}, respectively. This compares with {sup 210}Po concentration values (N=2, wet weight) of 27, 207, and 68 Bq kg{sup -1} measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated bioaccumulation factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for {sup 210}Po that those of {sup 137}Cs. We conclude from radiological dose estimates that ingestion of {sup 137}Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessing health risks to Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic.

  3. Structure and Dynamics of Minke Whale Surfacing Patterns in the Gulf of St. Lawrence, Canada

    PubMed Central

    Christiansen, Fredrik; Lusseau, David; Tscherter, Ursula

    2015-01-01

    Animal behavioral patterns can help us understand physiological and ecological constraints on animals and its influence on fitness. The surfacing patterns of aquatic air-breathing mammals constitute a behavioral pattern that has evolved as a trade-off between the need to replenish oxygen stores at the surface and the need to conduct other activities underwater. This study aims to better understand the surfacing pattern of a marine top predator, the minke whale (Balaenoptera acutorostrata), by investigating how their dive duration and surfacing pattern changes across their activity range. Activities were classified into resting, traveling, surface feeding and foraging at depth. For each activity, we classified dives into short and long dives and then estimated the temporal dependence between dive types. We found that minke whales modified their surfacing pattern in an activity-specific manner, both by changing the expression of their dives (i.e. density distribution) and the temporal dependence (transition probability) between dive types. As the depth of the prey layer increased between activities, the surfacing pattern of foraging whales became increasingly structured, going from a pattern dominated by long dives, when feeding at the surface, to a pattern where isolated long dives were followed by an increasing number of breaths (i.e. short dives), when the whale was foraging at depth. A similar shift in surfacing pattern occurred when prey handling time (inferred from surface corralling maneuvers) increased for surface feeding whales. The surfacing pattern also differed between feeding and non-feeding whales. Resting whales did not structure their surfacing pattern, while traveling whales did, possibly as a way to minimize cost of transport. Our results also suggest that minke whales might balance their oxygen level over multiple, rather than single, dive cycles. PMID:25970425

  4. DISTRIBUTION AND TRANSFORMATION OF ELEMENTAL MERCURY IN THE ST. LAWRENCE RIVER AND LAKE ONTARIO. (R827915)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  5. Marine mammal strandings and environmental changes: a 15-year study in the St. Lawrence ecosystem.

    PubMed

    Truchon, Marie-Hélène; Measures, Lena; L'Hérault, Vincent; Brêthes, Jean-Claude; Galbraith, Peter S; Harvey, Michel; Lessard, Sylvie; Starr, Michel; Lecomte, Nicolas

    2013-01-01

    Understanding the effects of climatic variability on marine mammals is challenging due to the complexity of ecological interactions. We used general linear models to analyze a 15-year database documenting marine mammal strandings (1994-2008; n?=?1,193) and nine environmental parameters known to affect marine mammal survival, from regional (sea ice) to continental scales (North Atlantic Oscillation, NAO). Stranding events were more frequent during summer and fall than other seasons, and have increased since 1994. Poor ice conditions observed during the same period may have affected marine mammals either directly, by modulating the availability of habitat for feeding and breeding activities, or indirectly, through changes in water conditions and marine productivity (krill abundance). For most species (75%, n?=?6 species), a low volume of ice was correlated with increasing frequency of stranding events (e.g. R(2)adj?=?0.59, hooded seal, Cystophora cristata). This likely led to an increase in seal mortality during the breeding period, but also to increase habitat availability for seasonal migratory cetaceans using ice-free areas during winter. We also detected a high frequency of stranding events for mysticete species (minke whale, Balaenoptera acutorostrata) and resident species (beluga, Delphinapterus leucas), correlated with low krill abundance since 1994. Positive NAO indices were positively correlated with high frequencies of stranding events for resident and seasonal migratory cetaceans, as well as rare species (R(2)adj?=?0.53, 0.81 and 0.34, respectively). This contrasts with seal mass stranding numbers, which were negatively correlated with a positive NAO index. In addition, an unusual multiple species mortality event (n?=?114, 62% of total annual mortality) in 2008 was caused by a harmful algal bloom. Our findings provide an empirical baseline in understanding marine mammal survival when faced with climatic variability. This is a promising step in integrating stranding records to monitor the consequences of environmental changes in marine ecosystems over long time scales. PMID:23544059

  6. St. Louis Sites Fact Sheet NORTH ST. LOUIS COUNTY

    E-print Network

    US Army Corps of Engineers

    St. Louis Sites Fact Sheet NORTH ST. LOUIS COUNTY SITES RECORD OF DECISION "Gateway to Excellence" U.S. Army Corps of Engineers St. Louis District The North St. Louis County Sites Record of Decision (ROD) was finalized on September 2, 2005. These sites consist of the St. Louis Airport Site (SLAPS

  7. St. Louis Sites Fact Sheet NORTH ST. LOUIS SITES

    E-print Network

    US Army Corps of Engineers

    St. Louis Sites Fact Sheet NORTH ST. LOUIS SITES REMEDIAL DESIGN/REMEDIAL ACTION "Gateway to Excellence" U.S. Army Corps of Engineers St. Louis District BACKGROUND Under contracts with the Manhattan from ore at the St. Louis Downtown Site (SLDS) in St. Louis, Missouri from 1942 to 1957. During

  8. MAPPING BURROWING SHRIMP AND SEAGRASS IN YAQUINA ESTUARY

    EPA Science Inventory

    Burrowing shrimp and seagrasses create extensive intertidal and shallow subtidal habitats within Pacific NW estuaries. Maps of their populations are useful to inform estuarine managers of locations that deserve special consideration for conservation, and to inform oyster farmers...

  9. CASCO BAY ESTUARY PROJECT TRIENNIAL IMPLEMENTATION REVIEW MARCH, 2004

    EPA Science Inventory

    The Casco Bay Estuary Project has seven primary goals/priorities which include: minimize pollutant loading from stormwater; open and protect shellfish beds; protect and restore habitat; reduce toxic pollution; promote responsible stewardship; sustain and promote the continued eff...

  10. SAN JUAN BAY ESTUARY PROGRAM IMPLEMENTATION REVIEW ATTACHMENTS

    EPA Science Inventory

    A compilation of attachments referenced in the San Juan Bay Estuary Program Implementation Review (2004). Materials include, entity reports, water and sediment quality action plans, progress reports, correspondence with local municipalities and Puerto Rican governmental agencies,...

  11. OXYGEN UPTAKE AND NUTRIENT REGENERATION IN THE PECONIC ESTUARY

    EPA Science Inventory

    EXECUTIVE SUMMARY: OXYGEN UPTAKE AND NUTRIENT REGENERATION IN THE PECONIC ESTUARY Rates of oxygen consumption and nutrient regeneration were measured annually throughout the Peconic Estuarine System. Sediment and water column oxygen uptake were measured to determine the potential...

  12. Mixing processes and hydraulic control in a highly stratified estuary

    E-print Network

    MacDonald, Daniel George, 1970-

    2003-01-01

    This thesis utilizes field data from the Fraser River Estuary, a highly stratified system located in southwestern British Columbia, Canada, to investigate the nature of mixing processes in a highly stratified environment, ...

  13. INTRODUCTION The euryhaline killifish Fundulus heteroclitus lives in estuaries and

    E-print Network

    Scott, Graham

    2450 INTRODUCTION The euryhaline killifish Fundulus heteroclitus lives in estuaries and salt been used extensively to understand fish osmoregulation (Wood and Marshall, 1994), the mechanisms for divergent physiological mechanisms of ion transport in freshwater between these two organs (Wood

  14. Landscape Thresholds and the Condition of Northeastern Estuaries

    EPA Science Inventory

    Anthropogenic impacts to northeastern estuaries have been well documented and many researchers have quantified the associations between broad scale human land uses in contributing landscapes and impacted estuarine condition. However, associations alone are not adequate for ident...

  15. FRESHWATER INFLOWS: WATER FOR HEALTHY ESTUARIES CONFERENCE (MX96476507

    EPA Science Inventory

    The grantee will hold an interstate workshop on Freshwater Inflow issues in the Gulf of Mexico coastal region. The conference will identify water management questions to be addressed regarding providing freshwater inflows to estuaries, update participants on the current scientif...

  16. BARNEGAT BAY ESTUARY PROGRAM - OCEAN COUNTY BUILD-OUT ANALYSIS

    EPA Science Inventory

    Rutgers University, under contract with NJDEP, using funds available through Section 320 of the Clean Water Act (National Estuary Program), has completed an analysis of possible future conditions of the Barnegat Bay watershed using existing zoning ordinances throughout Ocean Coun...

  17. Evaluating Causes of Ecological Impairments in the Estuaries of Ukraine

    EPA Science Inventory

    Ukrainian estuaries have not undergone a systematic evaluation of the causes of ecological impairments caused by anthropogenic contamination. The objective of this evaluation is to use recently developed diagnostic tools to determine the causes of benthic ecological impairments. ...

  18. BACTERIOPLANKTON DYNAMICS IN A SUBTROPICAL ESTUARY: EVIDENCE FOR SUBSTRATE LIMITATION

    EPA Science Inventory

    Bacterioplankton abundance and metabolic characteristics were measured along a transect in Pensacola Bay, Florida, USA, to examine the factors that control microbial water column processes in this subtropical estuary. The microbial measures included 3 H-L-leucine incorporation, e...

  19. HIGH CYANOBACTERIAL ABUNDANCE IN GULF OF MEXICO ESTUARIES

    EPA Science Inventory

    Aquatic phytoplankton comprise a wide variety of taxa spanning more than 2 orders of magnitude in size, yet studies of estuarine phytoplankton often overlook the picoplankton, particularly chroococcoid cyanobacteria (c.f. Synechocococcus). Three Gulf of Mexico estuaries (Apalachi...

  20. MODIS water quality algorithms for northwest Florida estuaries

    EPA Science Inventory

    Synoptic and frequent monitoring of water quality parameters from satellite is useful for determining the health of aquatic ecosystems and development of effective management strategies. Northwest Florida estuaries are classified as optically-complex, or waters influenced by chlo...

  1. DOWNSTREAM MIGRATION OF SALMONID SMOLTS IN OREGON RIVERS AND ESTUARIES

    EPA Science Inventory

    Migratory fish passage is an important designated use for many Oregon estuaries. Acoustic transmitters were implanted in coho smolts in 2004 and 2006 to evaluate how estuarine habitat, and habitat loss, might affect population health. Acoustic receivers that identified individu...

  2. NEKTON-HABITAT ASSOCIATIONS IN A PACIFIC NORTHWEST (USA) ESTUARY

    EPA Science Inventory

    Nekton?habitat associations were determined in Yaquina Bay, Oregon, United States, using a stratified-by-habitat, random, estuary-wide sampling design. Three habitats (intertidal eelgrass [Zostera marina], mud shrimp [Upogebia pugettensis], and ghost shrimp [Neotrypaea californie...

  3. Nutrients, hypoxia and Mass Fishkill events in Tapi Estuary, India

    NASA Astrophysics Data System (ADS)

    Ram, Anirudh; Jaiswar, Jiyalal Ram M.; Rokade, M. A.; Bharti, S.; Vishwasrao, C.; Majithiya, D.

    2014-07-01

    From 1983 to 2011, dissolved oxygen (DO) conditions in the Tapi Estuary changed from normoxic to hypoxic due to increased and untreated discharge of sewage. Both tidal and day-night variations of DO were best explained by hydrographic factors, sewage pollution and phytoplankton dynamics in upper, middle, lower estuary and the coastal water. Hypoxia/anoxia was associated with low-flow periods due to riverine restrictions and changing in climatic condition. The upper Tapi Estuary becomes anoxic during summer irrespective of tide while the middle estuary was anoxic (<0.2 mg O2 l-1) during post and premonsoon seasons and hypoxic (<2.0 mg O2 l-1) during monsoon season. Differences in the degree of stratification, sewage discharge and flushing accounted for differences in DO. Because of high nutrient concentrations (maximum NO3--N 103.1, NO2--N 26.0, NH4+-N 104.0 and PO43--P 99.0 ?mol l-1), the lower estuary remains DO deficient between 2.0 and 5.0 mg O2 l-1, most of the time. The environmental condition of Tapi Estuary has impacted the coastal water of the Arabian Sea in recent years with fish kills attributed to its hypoxic/anoxic condition. Enhanced concentrations of nutrients and organic matter from indiscriminate discharge of sewage into the Tapi Estuary and restricted flushing as a result of construction of a series of dams in the catchment area of the estuary are the primary factors that have lead to the development of hypoxia.

  4. Biological effects of anthropogenic contaminants in the San Francisco Estuary

    USGS Publications Warehouse

    Thompson, B.; Adelsbach, T.; Brown, C.; Hunt, J.; Kuwabara, J.; Neale, J.; Ohlendorf, H.; Schwarzbach, S.; Spies, R.; Taberski, K.

    2007-01-01

    Concentrations of many anthropogenic contaminants in the San Francisco Estuary exist at levels that have been associated with biological effects elsewhere, so there is a potential for them to cause biological effects in the Estuary. The purpose of this paper is to summarize information about biological effects on the Estuary's plankton, benthos, fish, birds, and mammals, gathered since the early 1990s, focusing on key accomplishments. These studies have been conducted at all levels of biological organization (sub-cellular through communities), but have included only a small fraction of the organisms and contaminants of concern in the region. The studies summarized provide a body of evidence that some contaminants are causing biological impacts in some biological resources in the Estuary. However, no general patterns of effects were apparent in space and time, and no single contaminant was consistently related to effects among the biota considered. These conclusions reflect the difficulty in demonstrating biological effects due specifically to contamination because there is a wide range of sensitivity to contaminants among the Estuary's many organisms. Additionally, the spatial and temporal distribution of contamination in the Estuary is highly variable, and levels of contamination covary with other environmental factors, such as freshwater inflow or sediment-type. Federal and State regulatory agencies desire to develop biological criteria to protect the Estuary's biological resources. Future studies of biological effects in San Francisco Estuary should focus on the development of meaningful indicators of biological effects, and on key organism and contaminants of concern in long-term, multifaceted studies that include laboratory and field experiments to determine cause and effect to adequately inform management and regulatory decisions. ?? 2006 Elsevier Inc. All rights reserved.

  5. Reprint of Water renewal timescales in the Scheldt Estuary

    NASA Astrophysics Data System (ADS)

    de Brye, Benjamin; de Brauwere, Anouk; Gourgue, Olivier; Delhez, Eric J. M.; Deleersnijder, Eric

    2013-12-01

    Using the concepts of the Constituent-oriented Age and Residence time Theory (CART), we compute timescales related to the water renewal in the Scheldt Estuary (The Netherlands/Belgium). Three different timescales are used to better understand and characterize the dynamics of the estuary: the age of the renewing water, the residence time and the exposure time. The residence time is the time taken by a water parcel to leave the estuary for the first time while the exposure time is the total time spent by a water parcel in the estuary including re-entries. The age of a renewing water parcel is defined as the time elapsed since it entered the estuary. The renewing water was split into three types: the water originating from the sea, the water originating from the upstream fresh tidal rivers and the water originating from the different canals and docks connected to the estuary. Every timescale is computed at any time and position by means of the finite-element, unstructured-mesh model SLIM. This results in movies of the timescale fields (shown as Supplementary material), allowing a detailed analysis of their spatial and temporal variabilities. The effect of the M2 tide and the discharge regime (winter, summer or average situation) on the timescales is also investigated.Tidally-averaged timescales vary little over the width of the estuary and hence exhibit a virtually one-dimensional behaviour. However, around these average values, the timescales can vary hugely over a tidal cycle, with amplitudes that significantly depend on the space coordinates. The reason thereof has yet to be elucidated. These results underscore the need for two- or three-dimensional models with high temporal resolution for investigating the dynamics of the Scheldt Estuary.

  6. Juvenile salmon usage of the Skeena River estuary.

    PubMed

    Carr-Harris, Charmaine; Gottesfeld, Allen S; Moore, Jonathan W

    2015-01-01

    Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2-8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations that use the estuary, then numerous fisheries would also be negatively affected. PMID:25749488

  7. Juvenile Salmon Usage of the Skeena River Estuary

    PubMed Central

    Carr-Harris, Charmaine; Gottesfeld, Allen S.; Moore, Jonathan W.

    2015-01-01

    Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2–8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations that use the estuary, then numerous fisheries would also be negatively affected. PMID:25749488

  8. Remote sensing of tidal chlorophyll-a variations in estuaries

    USGS Publications Warehouse

    Catts, Glenn P.; Khorram, Siamak; Cloern, James E.; Knight, Allen W.; Degloria, Stephen D.

    1985-01-01

    Knowledge of the distribution of phytoplankton and the location of this zone of high biomass is valuable in establishing management policies for this ecologically important estuary. Furthermore, the techniques used here may provide an alternative cost-effective method for assessing water-quality conditions and they may prove useful for studying spatial variations (patchiness) and seasonal variations in phytoplankton biomass in other estuaries and coastal waters.

  9. Continuous resistivity profiling data from the Corsica River Estuary, Maryland

    USGS Publications Warehouse

    Cross, V.A.; Bratton, J.F.; Worley, C.R.; Crusius, J.; Kroeger, K.D.

    2011-01-01

    Submarine groundwater discharge (SGD) into Maryland's Corsica River Estuary was investigated as part of a larger study to determine its importance in nutrient delivery to the Chesapeake Bay. The Corsica River Estuary represents a coastal lowland setting typical of much of the eastern bay. An interdisciplinary U.S. Geological Survey (USGS) science team conducted field operations in the lower estuary in April and May 2007. Resource managers are concerned about nutrients that are entering the estuary via SGD that may be contributing to eutrophication, harmful algal blooms, and fish kills. Techniques employed in the study included continuous resistivity profiling (CRP), piezometer sampling of submarine groundwater, and collection of a time series of radon tracer activity in surface water. A CRP system measures electrical resistivity of saturated subestuarine sediments to distinguish those bearing fresh water (high resistivity) from those with saline or brackish pore water (low resistivity). This report describes the collection and processing of CRP data and summarizes the results. Based on a grid of 67.6 kilometers of CRP data, low-salinity (high-resistivity) groundwater extended approximately 50-400 meters offshore from estuary shorelines at depths of 5 to >12 meters below the sediment surface, likely beneath a confining unit. A band of low-resistivity sediment detected along the axis of the estuary indicated the presence of a filled paleochannel containing brackish groundwater. The meandering paleochannel likely incised through the confining unit during periods of lower sea level, allowing the low-salinity groundwater plumes originating from land to mix with brackish subestuarine groundwater along the channel margins and to discharge. A better understanding of the spatial variability and geological controls of submarine groundwater flow beneath the Corsica River Estuary could lead to improved models and mitigation strategies for nutrient over-enrichment in the estuary and in other similar settings.

  10. Monitoring Rehabilitation in Temperate North American Estuaries

    SciTech Connect

    Rice, Casimir A.; Hood, W Gregory; Tear, Lucinda M.; Simenstad, Charles; Williams, Gregory D.; Johnson, L. L.; Feist, B. E.; Roni, P.

    2005-02-01

    In this chapter, we propose that monitoring rehabilitation in estuarine ecosystems by necessity requires quantifying relationships between dynamic estuarine processes and sensitive indicators of ecosystem function. While we do discuss temperate systems in general, emphasis is placed on anadromous salmon habitats in the Pacific Northwest because anadromous fishes are such a major focus of rehabilitation efforts, and present some of the greater challenges in linking function of one segment of their life history to conditions in a specific habitat. We begin with a basic overview of the ecological and socioeconomic significance of, as well as anthropogenic effects on, estuaries. Next, we briefly summarize the various kinds of estuarine rehabilitation historically practiced in temperate regions, and review estuarine rehabilitation monitoring design and methods, highlighting the unique challenges involved in monitoring estuarine systems. We then close with a summary and conclusions.

  11. Yeast community survey in the Tagus estuary.

    PubMed

    de Almeida, João M G C F

    2005-07-01

    The yeast community in the waters of the Tagus estuary, Portugal, was followed for over a year in order to assess its dynamics. Yeast occurrence and incidence were measured and this information was related to relevant environmental data. Yeast occurrence did not seem to depend upon tides, but river discharge had a dramatic impact both on the density and diversity of the community. The occurrence of some yeasts was partially correlated with faecal pollution indicators. Yeast isolates were characterized by microsatellite primed PCR (MSP-PCR) fingerprinting and rRNA gene sequencing. The principal species found were Candida catenulata, C. intermedia, C. parapsilosis, Clavispora lusitaniae, Debaryomyces hansenii, Pichia guilliermondii, Rhodotorula mucilaginosa and Rhodosporidium diobovatum. The incidence of these species was evaluated against the environmental context of the samples and the current knowledge about the substrates from which they are usually isolated. PMID:16329949

  12. Columbia Bay, Alaska: an 'upside down' estuary

    USGS Publications Warehouse

    Walters, R.A.; Josberger, E.G.; Driedger, C.L.

    1988-01-01

    Circulation and water properties within Columbia Bay, Alaska, are dominated by the effects of Columbia Glacier at the head of the Bay. The basin between the glacier terminus and the terminal moraine (sill depth of about 22 m) responds as an 'upside down' estuary with the subglacial discharge of freshwater entering at the bottom of the basin. The intense vertical mixing caused by the bouyant plume of freshwater creates a homogeneous water mass that exchanges with the far-field water through either a two- or a three-layer flow. In general, the glacier acts as a large heat sink and creates a water mass which is cooler than that in fjords without tidewater glaciers. The predicted retreat of Columbia Glacier would create a 40 km long fjord that has characteristics in common with other fjords in Prince William Sound. ?? 1988.

  13. Nonlinear interactions of waves and tides in a subterranean estuary

    NASA Astrophysics Data System (ADS)

    Xin, Pei; Wang, Shen S. J.; Lu, Chunhui; Robinson, Clare; Li, Ling

    2015-04-01

    Previous studies have revealed hysteretic behavior in subterranean estuaries in response to intensified wave conditions caused by offshore storm events, showing dependence of submarine groundwater discharge (SGD) and subsurface salt distribution on historic wave conditions. Although most shorelines worldwide are also exposed to tidal fluctuations, it is unclear how tides moderate wave-induced SGD and salinity distribution in subterranean estuaries. This study presents numerical simulations that explore the combined influence of intensified wave conditions and tides on groundwater flow and salt transport in a subterranean estuary. The results show that tides weaken the hysteretic wave effect on SGD, suggesting that a tidally influenced subterranean estuary is less sensitive to intensified wave conditions with respect to the water fluxes across the aquifer-sea interface. However, due to enhancement of salt-freshwater mixing, tides strengthen the hysteretic wave effect on the salt fluxes across the aquifer-sea interface, prolonging the recovery of salt distribution in the subterranean estuary to the prestorm state. These findings reveal the nonlinear, coupling nature of processes driven by oceanic oscillations at different time scales in subterranean estuaries.

  14. PCBs in the fish assemblage of a southern European estuary

    NASA Astrophysics Data System (ADS)

    Baptista, Joana; Pato, Pedro; Pereira, Eduarda; Duarte, Armando C.; Pardal, Miguel A.

    2013-02-01

    The Mondego estuary fish assemblage was studied for the accumulation of PCBs. Three sampling stations were visited along an estuarine salinity gradient, and, in total, 15 species were collected. Analysis of PCBs revealed no significant differences among the sampling stations, although differences were observed among the fish assemblages. Fish assemblages could be divided into three groups. The first group comprised those with higher concentration (more than 10 ng g- 1, dw), included the species Gobius niger, Sardina pilchardus, Anguilla anguilla, Pomatoschistus microps, Chelidonichthys lucerna and Liza ramada; the second group with medium concentration (5-10 ng g- 1, dw), included the species Pomatoschistus minutus, Dicentrarchus labrax, Atherina presbyter, Chelon labrosus, Diplodus vulgaris, Platichthys flesus and Cilata mustela; and a third group with low concentration (less than 5 ng g- 1, dw), included the species Solea solea and Callionymus lyra. A positive correlation was found between lipid content and PCB concentrations. To evaluate the influence of the residence time of species on the accumulation of PCBs, species were divided into two groups: species that spend more than 3 years in the estuary, and species that spend less than 3 years in the estuary. Species that spend more than 3 years in the estuary presented higher concentrations than species that spend less than 3 years in the estuary. CBs 138 and 153 had higher concentration, and tended to increase with time spent in the estuary.

  15. WESTERN BLVD HILLSBOROUGH ST

    E-print Network

    Barlaz, Morton A.

    MORRILL DR NEELEY ST M AIN CAM PUS DR CARLTONAVE OKELLY ST BRENT RD PRICEST VANDERBILT AVE GARDNERST Motor Pool Solar House BellTower Lee Lot 'RW' Zone West Deck Avent Ferry 'P' Zone Wolf Village North (Main) Lot Private Parking Deck Reclamation Zone Jeter Drive Bays Boney Drive Lot Mckimmon Vistor Lot

  16. 21st Century Scholars

    ERIC Educational Resources Information Center

    Clark, Terrence

    2009-01-01

    Bethpage Union Free School District in New York is a high-performing district by almost any current accountability measure. Yet administrators and teachers worried that they were not doing enough to prepare their students as critical thinkers for the 21st century. Inspired by the curriculum framework of the Partnership for 21st Century Skills, the…

  17. Ernest Orlando Lawrence (1901-1958), Cyclotron and Medicine

    SciTech Connect

    Chu, William T.

    2005-09-01

    On August 8, 2001, Lawrence Berkeley National Laboratory celebrated the centennial of the birth of its founder (and namesake), Ernest Orlando Lawrence. For the occasion, many speeches were given and old speeches were remembered. We recall the words of the late Luis Alvarez, a Nobel Laureate and one of the Lawrence's closest colleagues: ''Lawrence will always be remembered as the inventor of the cyclotron, but more importantly, he should be remembered as the inventor of the modern way of doing science''. J. L. Heilbron and R. W. Seidel, in the introduction of their book, ''Lawrence and His Laboratory'' stated, ''The motives and mechanisms that shaped the growth of the Laboratory helped to force deep changes in the scientific estate and in the wider society. In the entrepreneurship of its founder, Ernest Orlando Lawrence, these motives, mechanisms, and changes came together in a tight focus. He mobilized great and small philanthropists, state and local governments, corporations, and plutocrats, volunteers and virtuosos. The work they supported, from astrophysics and atomic bombs, from radiochemistry to nuclear medicine, shaped the way we observe, control, and manipulate our environment.'' Indeed, all over the civilized world, the ways we do science changed forever after Lawrence built his famed Radiation Laboratory. In this editorial, we epitomize his legacy of changing the way we do medicine, thereby affecting the health and well being of all humanity. This year marks the 75th anniversary of the invention of the cyclotron by Ernest Orlando Lawrence at the University of California at Berkeley. Lawrence conceived the idea of the cyclotron early in 1929 after reading an article by Rolf Wideroe on high-energy accelerators. In the spring of 1930 one of his students, Nels Edlefsen, constructed two crude models of a cyclotron. Later in the fall of the same year, another student, M. Stanley Livingston, constructed a 13-cm diameter model that had all the features of early cyclotrons, accelerating protons to 80,000 volts using less than 1,000 volts on a semi-circular accelerating electrode, now called the ''dee''. Following the discovery by J. D. Cockcroft and E. T. S. Walton of how to produce larger currents at higher voltages, Lawrence constructed the first two-dee 27-Inch (69-cm) Cyclotron, which produced protons and deuterons of 4.8 MeV. The 27-Inch Cyclotron was used extensively in early investigations of nuclear reactions involving neutrons and artificial radioactivity. In 1939, working with William Brobeck, Lawrence constructed the 60-Inch (150-cm) Cyclotron, which accelerated deuterons to 19 MeV. It was housed in the Crocker Laboratory, where scientists first made transmutations of some elements, discovered several transuranic elements, and created hundreds of radioisotopes of known elements. At the Crocker Laboratory the new medical modality called nuclear medicine was born, which used radioisotopes for diagnosis and treatment of human diseases. In 1939 Lawrence was awarded the Nobel Prize in Physics, and later element 103 was named ''Lawrencium'' in his honor.

  18. Obituary: Fred Lawrence Whipple, 1906-2004

    NASA Astrophysics Data System (ADS)

    Yeomans, Donald Keith

    2004-12-01

    Fred Whipple, one of the founding fathers of planetary science, died on August 30, 2004 just two months shy of his 98th birthday. The breadth of Fred's published research from 1927 through 2000 is quite extraordinary. Although his collected works were published in two massive volumes in 1972, shortly before his retirement, Fred's research contributions continued for another three decades - and another volume is planned. Fred Lawrence Whipple was born on November 5, 1906 on a farm in Red Oak Iowa. His parents were Harry Lawrence and Celestia (MacFarl) Whipple. At the age of fifteen, the Whipple family moved to California where Fred studied mathematics at Occidental College and the University of California at Los Angeles. As a graduate student at the University of California at Berkeley in 1930, he was one of the first to compute an orbit for the newly discovered planet Pluto. Upon receiving his PhD in 1931, he joined the staff of the Harvard College Observatory. He was Chairman of the Harvard Department of Astronomy (1949 - 1956), Director or the Smithsonian Astrophysical Observatory (1955 - 1973), Phillips Professor of Astronomy (1968 - 1977) and Emeritus Phillips Professor of astronomy (1977 - 2004). In 1928 he married Dorothy Woods and their son, Earle Raymond, survives him. The marriage ended in divorce in 1935. Eleven years later, he married Babette F. Samelson and she too survives him, as do their two daughters Laura and (Dorothy) Sandra. Shortly after arriving at Harvard in the early 1930's, Fred developed a photographic tracking network to determine meteor trajectories from simultaneous observations from two or more stations. The photographic trails, chopped by a rotating shutter, allowed their orbits in space to be determined accurately. With the strong involvement of Richard McCrosky and others, he concluded in the early 1960's that most of these meteors were on comet-like orbits and less than 1% of the naked eye, sporadic meteors could be traced to an origin outside the solar system. To fill the daytime gap when meteors could not be photographed, Fred organized a program for the radio detection of these objects. With the launch of Sputnik in October 1957, Whipple's visual network of amateur astronomers (Moon watch) was already in place to follow its progress and later on he developed an optical tracking system for meteors and artificial satellites using wide field, Baker-Nunn cameras. This latter system proved so successful that the precision tracking of these satellites could be used to model the Earth's shape and density variations from the observed gravitational effects upon these satellite orbits. He once noted that the highlight of his career was having his family and parents present at the White House while he received the President's Award for Distinguished Public Service from John F. Kennedy for this work. His seminal works in 1950-51 on the icy conglomerate model for the cometary nucleus prompted a complete paradigm switch. Until then, the current consensus model for a comet was a flying cloud of particles; it had been so since the second half of the nineteenth century when comets were identified with meteor showers. He envisaged the cometary nucleus as a conglomerate of ices (mostly water, ammonia, methane, carbon dioxide and carbon monoxide ices) embedded within, and covered over with, a nonvolatile matrix of meteoric material. Part of his rationale for developing this "dirty snowball" model for the cometary nucleus was to provide an explanation of the so-called nongravitational forces acting upon comets. The rocket-like thrusting of a comet when the ices vaporize near the sun introduced a small, but noticeable, thrust on the comet itself and when this effect was properly modeled, the motions of active comets could be predicted far more accurately. Subsequent spacecraft ultraviolet observations showing enormous cometary hydrogen atmospheres confirmed that the major cometary ice was likely to be water. The 1986 Giotto spacecraft images, revealing a solid cometary nucleus (albeit far blacker

  19. Connectivity, neutral theories and the assessment of species vulnerability to global change in temperate estuaries

    E-print Network

    Borges, Rita

    in temperate estuaries Guillem Chust a,*, Aitor Albaina b , Aizkorri Aranburu a , Ángel Borja a , Onno E 2013 Keywords: Zostera Cerastoderma diversity climate change estuary neutral theory a b s t r a c t One

  20. CLASSIFYING OREGON ESTUARIES BY HABITAT: ANALYSIS OF EXISTING DATA AND A PROPOSAL FOR A PILOT STUDY

    EPA Science Inventory

    Because many estuarine resources are linked to benthic habitats, classification of estuaries by habitat types may prove a relevant approach for grouping estuaries with similar ecological values and vulnerability to landscape alterations. As a first step, we evaluated whether pub...

  1. 76 FR 23306 - Takes of Marine Mammals Incidental to Specified Activities; Russian River Estuary Management...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-26

    ...water surface elevation management in the estuary-lagoon system. SCWA's estuary management activities generally...approximately during the lagoon management period (mid- May through...depending on river dynamics. Beach...

  2. Tidal asymmetry in estuaries with mixed semidiurnal/diurnal tides

    NASA Astrophysics Data System (ADS)

    Nidzieko, Nicholas J.

    2010-08-01

    Tidal asymmetry in estuaries with mixed, mainly semidiurnal tides arises from both the interaction of principal tides and the higher harmonics generated by distortions within the estuary. The duration asymmetry in rise and fall of water level caused by principal tides on the west coast of the continental United States is ebb-dominant, and so the tide entering estuaries is also ebb-dominant, prior to any internal distortions within the estuary. The interaction of higher harmonics with principal constituents either augments or cancels the duration asymmetry in the principal tides. In estuaries where tidal elevation and velocity phase are near quadrature (90° out of phase), the duration asymmetry in tidal elevation leads to asymmetries in tidal current magnitude. Asymmetry can be conveniently quantified in terms of the sample skewness, ?1, the normalized third sample moment about the mean. An analytic approximation to the skewness shows that traditional metrics of asymmetry, namely the ratio of constituent amplitudes and the relative constituent phase difference, arise from calculating the third sample moment. Observations from three California estuaries of different morphologies are presented as an illustration of how skewness can be used to quantify asymmetry in real systems. As in semidiurnal systems, morphology is a good predictor of whether higher harmonics engender ebb-dominance or flood-dominance, however asymmetry imposed by principal tides at the mouth must first be overcome and so there is a spatial evolution in the total asymmetry. Quantifying observations via skewness should be considered in addition to traditional metrics in estuaries with mixed tides.

  3. Hydrodynamic controls on oxygen dynamics in a riverine salt wedge estuary, the Yarra River estuary, Australia

    NASA Astrophysics Data System (ADS)

    Bruce, L. C.; Cook, P. L. M.; Teakle, I.; Hipsey, M. R.

    2014-04-01

    Oxygen depletion in coastal and estuarine waters has been increasing rapidly around the globe over the past several decades, leading to decline in water quality and ecological health. In this study we apply a numerical model to understand how salt wedge dynamics, changes in river flow and temperature together control oxygen depletion in a micro-tidal riverine estuary, the Yarra River estuary, Australia. Coupled physical-biogeochemical models have been previously applied to study how hydrodynamics impact upon seasonal hypoxia; however, their application to relatively shallow, narrow riverine estuaries with highly transient patterns of river inputs and sporadic periods of oxygen depletion has remained challenging, largely due to difficulty in accurately simulating salt wedge dynamics in morphologically complex areas. In this study we overcome this issue through application of a flexible mesh 3-D hydrodynamic-biogeochemical model in order to predict the extent of salt wedge intrusion and consequent patterns of oxygen depletion. The extent of the salt wedge responded quickly to the sporadic riverine flows, with the strength of stratification and vertical density gradients heavily influenced by morphological features corresponding to shallow points in regions of tight curvature ("horseshoe" bends). The spatiotemporal patterns of stratification led to the emergence of two "hot spots" of anoxia, the first downstream of a shallow region of tight curvature and the second downstream of a sill. Whilst these areas corresponded to regions of intense stratification, it was found that antecedent conditions related to the placement of the salt wedge played a major role in the recovery of anoxic regions following episodic high flow events. Furthermore, whilst a threshold salt wedge intrusion was a requirement for oxygen depletion, analysis of the results allowed us to quantify the effect of temperature in determining the overall severity and extent of hypoxia and anoxia. Climate warming scenarios highlighted that oxygen depletion is likely to be exacerbated through changes in flow regimes and warming temperatures; however, the increasing risk of hypoxia and anoxia can be mitigated through management of minimum flow allocations and targeted reductions in organic matter loading. A simple statistical model (R2 > 0.65) is suggested to relate riverine flow and temperature to the extent of estuary-wide anoxia.

  4. Columbia River Estuary Ecosystem Classification Ecosystem Complex

    USGS Publications Warehouse

    Cannon, Charles M.; Ramirez, Mary F.; Heatwole, Danelle W.; Burke, Jennifer L.; Simenstad, Charles A.; O'Connor, Jim E.; Marcoe, Keith Marcoe

    2012-01-01

    Estuarine ecosystems 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 Ecosystem 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 ecosystem 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) Ecosystem Province; (2) Ecoregion; (3) Hydrogeomorphic Reach; (4) Ecosystem 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 current 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.

  5. Columbia River Estuary Ecosystem Classification Geomorphic Catena

    USGS Publications Warehouse

    Cannon, Charles M.; Ramirez, Mary F.; Heatwole, Danelle W.; Burke, Jennifer L.; Simenstad, Charles A.; O'Connor, Jim E.; Marcoe, Keith

    2012-01-01

    Estuarine ecosystems 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 Ecosystem 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 ecosystem 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) Ecosystem Province; (2) Ecoregion; (3) Hydrogeomorphic Reach; (4) Ecosystem 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 current 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.

  6. Columbia River Estuary Ecosystem Classification Hydrogeomorphic Reach

    USGS Publications Warehouse

    Cannon, Charles M.; Ramirez, Mary F.; Heatwole, Danelle W.; Burke, Jennifer L.; Simenstad, Charles A.; O'Connor, Jim E.; Marcoe, Keith

    2012-01-01

    Estuarine ecosystems 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 Ecosystem 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 ecosystem 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) Ecosystem Province; (2) Ecoregion; (3) Hydrogeomorphic Reach; (4) Ecosystem 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 current 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.

  7. Community structure of epibenthic meiofauna in the St. Lucia Estuarine Lake (South Africa) during a drought phase

    NASA Astrophysics Data System (ADS)

    Pillay, D.; Perissinotto, R.

    2009-01-01

    The St. Lucia Estuary is Africa's largest estuarine system. It is a major component of the iSimangaliso (formerly Greater St. Lucia) Wetland Park, which was declared a World Heritage Site in 1999. The system has been severely affected by drought conditions which have culminated in the mouth of the system being cut off from the Indian Ocean since June 2002, for a period of almost five years. This study aimed to document the dynamics of meiofauna of the system during a drought phase, since (1) the effects of droughts on estuaries are poorly documented and understood and (2) because studies of meiofauna have never been undertaken in this system before. Meiofauna samples as well as physico-chemical data were collected at representative sites in February, April, August and October 2005. The drought had a major effect on the estuary, resulting in the development of hypersaline conditions (maximum 126 at Hells Gate), and to the complete evaporation of pelagic habitats, especially in the northern regions. The meiofauna of the St. Lucia Estuary was statistically separated into two distinct spatial clusters under drought conditions. The first cluster comprised sites in the Narrows and the southern region of South Lake, while the second comprised sites in the northern regions of South Lake and False Bay. Meiofauna of cluster 1, which was least affected by the drought, comprised nematodes, polychaetes, copepods, amphipods and ostracods, all of which accounted for 97% of meiofauna in this cluster. Cluster 2 on the other hand, which was more severely affected by the drought, was dominated by nematodes and copepods, which cumulatively contributed 97% to meiofauna in this group. Taxonomic richness and diversity of meiofauna were positively correlated with water depth, while abundance was inversely correlated with water temperature. The major effects of low water levels on the meiofauna of the system occurred through a negative impact on diversity and taxonomic richness, resulting in assemblages dominated by taxa most physiologically suited to such conditions. Secondly, at the peak of the drought, there was discontinuous water flow in the St. Lucia Estuary, resulting in parts of the northern and southern regions of the system being fragmented. This could have prevented the spread of meiofaunal taxa between the different basins of the system, and also explains the spatial separation of meiofauna into distinct clusters within the estuary.

  8. The Spectra of Somatic Mutations Across Many Tumor Types - Michael Lawrence, TCGA Scientific Symposium 2011

    Cancer.gov

    Home News and Events Multimedia Library Videos The Spectra of Somatic Mutations Across Many Tumor Types - Michael Lawrence The Spectra of Somatic Mutations Across Many Tumor Types - Michael Lawrence, TCGA Scientific Symposium 2011 You will need Adobe

  9. THE CATEGORY THEORETIC SOLUTION OF RECURSIVE PROGRAM SCHEMES STEFAN MILIUS AND LAWRENCE S. MOSS

    E-print Network

    Moss, Lawrence S.

    THE CATEGORY THEORETIC SOLUTION OF RECURSIVE PROGRAM SCHEMES STEFAN MILIUS AND LAWRENCE S. MOSS;2 STEFAN MILIUS AND LAWRENCE S. MOSS 1. Introduction The theory of recursive program schemes (see [C, G, N

  10. 75 FR 1010 - CSX Transportation, Inc.-Discontinuance of Service Exemption-in Clark, Floyd, Lawrence, Orange...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-07

    ..., Floyd, Lawrence, Orange, and Washington Counties, IN On December 18, 2009, CSX Transportation, Inc... Albany, in Clark, Floyd, Lawrence, Orange, and Washington Counties, IN.\\1\\ The line traverses...

  11. ST 744 D. Zhang ST 744: Categorical Data Analysis

    E-print Network

    Zhang, Daowen

    ST 744 D. Zhang ST 744: Categorical Data Analysis Daowen Zhang zhang@stat.ncsu.edu http://www4.stat.ncsu.edu/dzhang2 Slide 1 #12;TABLE OF CONTENTS ST744, D. Zhang Contents 1 Review of Likelihood Inference #12;CHAPTER 1 ST744, D. Zhang 1 Review of Likelihood Inference & Introduction I. Review of Likelihood

  12. 6. VIEW FROM CHESTNUT ST. (upper), WALNUT ST. (lower) THIRD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW FROM CHESTNUT ST. (upper), WALNUT ST. (lower) THIRD ST. (right) AND FOURTH ST. (left), SHOWING CARPENTERS HALL, FIRST BANK OF U.S. AND SECOND BANK OF U.S. - Independence National Historical Park, Walnut, Sixth, Chestnut & Second Streets, Philadelphia, Philadelphia County, PA

  13. Horizontal distribution and population dynamics of the dominant mysid Hyperacanthomysis longirostris along a temperate macrotidal estuary (Chikugo River estuary, Japan)

    NASA Astrophysics Data System (ADS)

    Suzuki, Keita W.; Nakayama, Kouji; Tanaka, Masaru

    2009-08-01

    The estuarine turbidity maximum (ETM) that develops in the lower salinity areas of macrotidal estuaries has been considered as an important nursery for many fish species. Mysids are one of the dominant organisms in the ETM, serving as a key food source for juvenile fish. To investigate the horizontal distribution and population dynamics of dominant mysids in relation to the fluctuation of physical conditions (temperature, salinity, turbidity, and freshwater discharge), we conducted monthly sampling (hauls of a ring net in the surface water) along the macrotidal Chikugo River estuary in Japan from May 2005 to December 2006. Hyperacanthomysis longirostris was the dominant mysid in the estuary, usually showing peaks of density and biomass in or close to the ETM (salinity 1-10). In addition, intra-specific differences (life-cycle stage, sex, and size) in horizontal distribution were found along the estuary. Larger males and females, particularly gravid females, were distributed upstream from the center of distribution where juveniles were overwhelmingly dominant. Juveniles increased in size toward the sea in marked contrast with males and females. The findings suggest a possible system of population maintenance within the estuary; gravid females release juveniles in the upper estuary, juveniles grow during downstream transport, young males and females mature during the upstream migration. Density and biomass were primarily controlled by seasonal changes of temperature, being high at intermediate temperatures (ca. 15-25 °C in late spring and fall) and being low at the extreme temperatures (ca. 10 °C in midwinter and 30 °C in midsummer). High density (up to 666 ind. m -3) and biomass (up to 168 mg dry weight m -3) of H. longirostris were considered to be comparable with those of copepods in the estuary.

  14. Sediment balance of intertidal mudflats in a macrotidal estuary

    NASA Astrophysics Data System (ADS)

    lafite, R.; Deloffre, J.; Lemoine, M.

    2012-12-01

    Intertidal area contributes widely to fine-grained sediment balance in estuarine environments. Their sedimentary dynamics is controlled by several forcing parameters including tidal range, river flow and swell, affected by human activities such as dredging, construction or vessels traffic leading to modify sediment transport pattern. Although the estuarine hydrodynamics is well documented, the link between forcing parameters and these sedimentary processes is weakly understood. One of the main reasons is the difficulty to integrate spatial (from the fluvial to the estuary mouth) and temporal (from swell in seconds to pluriannual river flow variability) patterns. This study achieved on intertidal mudflats distributed along the macrotidal Seine estuary (France) aims (i) to quantify the impact of forcing parameters on each intertidal area respect to its longitudinal position in the estuarine system and (ii) to assess the fine-grained sediment budget at estuarine scale. The Seine estuary is a macrotidal estuary developed over 160 km up the upstream limit of tidal wave penetration. With an average river flow of 450m3.s-1, 80% of the Suspended Particles Matter (SPM) annual flux is discharged during the flood period. In the downstream part, the Seine estuary Turbidity Maximum (TM) is the SPM stock located near the mouth. During their transfer toward the sea, the fine particles can be trapped in (i) the intertidal mudflats; preferential areas characterized by low hydrodynamics and generally sheltered of the tidal dominant flow, the main tidal current the Seine River and (ii) the TM. The Seine estuary is an anthropic estuary in order to secure navigation: one consequence of these developments is the tidal bore disappearance. Along the macrotidal Seine estuary hydrodynamics features and sedimentary fluxes were followed during at least 1 year using respectively Acoustic Doppler Velocimeter, Optical BackScatter and altimeter. Results in the fluvial estuary enhance the role of hydrological cycle that lead to (i) an increased mean water level and (ii) provide SPM from the continental area. This feature leads to significant accretion over intertidal area. In the middle and marine estuary the TM is the main SPM supplier. In these parts of the estuary deposition over these intertidal area is driven by (i) tidal cycle in particular fortnightly cycle link to maximum TM resuspension during (strongest) spring tide and (ii) TM location controlled by river inflow that varies following an annual and inter-annual variability. Outside sedimentation period, the erosion is driven by the combination of (i) progressive erosion driven by fortnightly cycle and (ii) sudden erosion controlled either by wave or boat generated waves respectively at the mouth and in the middle/upper estuary. This last is reinforced by the rheological characteristics of deposit that correspond to fluid/low consolidated mud. During most of the year, the Seine estuary mudflats record an erosion pattern. Significant and intensive sedimentation only occurs few days per year. This pattern is linked to highly variable hydrodynamics conditions (bottom shear stress ranging from 0.5 to 5 N.m-2) that control the sediment supply availability. In this infilling macrotidal anthropized system mudflats are close to equilibrium with an annual rate ranging between +/- 5cm.yrs-1: they act as temporal storage area of fined-grained sediments.

  15. Determination of water mass ages using radium isotopes as tracers: Implications for phytoplankton dynamics in estuaries

    E-print Network

    dynamics in estuaries Gabrielle Tomasky-Holmes a , Ivan Valiela a , Matthew A. Charette b, a The Ecosystem-enclosed estuaries, phytoplankton blooms in nutrient enriched systems are a common phenomenon. This poses of shallow estuaries, if the water residence times are similar to cell division times? To address

  16. 5612004 Estuarine Research Federation Estuaries Vol. 27, No. 4, p. 561570 August 2004

    E-print Network

    MacCready, Parker

    5612004 Estuarine Research Federation Estuaries Vol. 27, No. 4, p. 561­570 August 2004 Toward-averaged, width-averaged estuarine salinity and circulation in a rectangular estuary. Width and depth may vary-channel distribution of the diffusive fraction of up-estuary salt flux. It is shown that the Hansen and Rattray

  17. 78 FR 68995 - Safety Zone: Vessel Removal From the Oakland Estuary, Alameda, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ...Zone: Vessel Removal From the Oakland Estuary, Alameda, CA AGENCY: Coast Guard...in the navigable waters of the Oakland Estuary just north of the Park Street Bridge in Alameda, CA in support of the Oakland Estuary Closure for the Vessel Removal...

  18. An Idealized Model and Systematic Process Study of Oxygen Depletion in Highly Turbid Estuaries

    E-print Network

    Horner-Devine, Alex

    An Idealized Model and Systematic Process Study of Oxygen Depletion in Highly Turbid Estuaries S. A The sensitivity of oxygen depletion in turbid estuaries to parameters like freshwater discharge, depth module of dissolved oxygen (DO). Based on the analysis of field data collected in the Ems estuary

  19. Many fish species use estuaries of the southeastern United States as nurser-

    E-print Network

    443 Many fish species use estuaries of the southeastern United States as nurser- ies (e.g. Skud with respect to habitat in different estuaries. Associa- tions between abundance and habitat can assist inflows to estuaries of the southeast United States have been severely altered in the last 150 years

  20. 10102003 Estuarine Research Federation Estuaries Vol. 26, No. 4B, p. 10101031 August 2003

    E-print Network

    Hickey, Barbara

    10102003 Estuarine Research Federation Estuaries Vol. 26, No. 4B, p. 1010­1031 August 2003 Oceanography of the U.S. Pacific Northwest Coastal Ocean and Estuaries with Application to Coastal Ecology of planktonic larvae and to the development of harmful algal blooms. The coastal plain estuaries

  1. 8251999 Estuarine Research Federation Estuaries Vol. 22, No. 4, p. 825836 December 1999

    E-print Network

    Mallin, Michael

    8251999 Estuarine Research Federation Estuaries Vol. 22, No. 4, p. 825­836 December 1999 Alternation of Factors Limiting Phytoplankton Production in the Cape Fear River Estuary MICHAEL A. MALLIN1 Fear River Estuary, a riverine system originating in the North Carolina piedmont. Nutrient addition

  2. 7562001 Estuarine Research Federation Estuaries Vol. 24, No. 5, p. 756769 October 2001

    E-print Network

    North, Elizabeth W.

    7562001 Estuarine Research Federation Estuaries Vol. 24, No. 5, p. 756­769 October 2001 Retention, a two-layer response to wind forcing shifted the ETM up-estuary, while a high discharge event resulted in a down-estuary shift in the salt front and ETM location. In 1999, extremely low discharge rates shifted

  3. How Estuaries Work: A Charlotte Harbor Example R.H. Weisberg and L. Zheng

    E-print Network

    Meyers, Steven D.

    How Estuaries Work: A Charlotte Harbor Example by R.H. Weisberg and L. Zheng College of Marine: "How estuaries work." The venue is the Charlotte Harbor on Florida's west coast, and the analysis medium is the primitive equation ECOM3D-si model. We are motivated by an estuary classification dilemma

  4. Estuaries are highly productive habi-tats that support a diversity of spe-

    E-print Network

    186 Estuaries are highly productive habi- tats that support a diversity of spe- cies, but have coastline. Fjord estuaries differ from other estuar- ies by possessing a deep inner basin that is separated from continental shelf waters by a shallow sill near the mouth of the estuary. Although some

  5. FISH LARVAE OF THE ESTUARIES AND COAST OF CENTRAL MAINE STANLEY B. CHENOWETH'

    E-print Network

    FISH LARVAE OF THE ESTUARIES AND COAST OF CENTRAL MAINE STANLEY B. CHENOWETH' ABSTRACT Seasonal in the winter and early spring. These hatched from demersal eggs and were concentrated in the upper estuaries. There is little information on the species com- position and abundance of larval fishes in the numerous estuaries

  6. Estuaries are more and more called upon to act as repositories for immediate direct point

    E-print Network

    ! " # ! $ ! % & ' $ ( ) * + ,- , * Estuaries are more and more called upon to act as repositories and naturally suited set of tools to investigate and model the transport pathways, mixing and ocean-estuary residence time scales within the estuary? How dependent are exchanges and pathways on the existence

  7. PEER REVIEW OF PECONIC ESTUARY PROGRAM HYDRODYNAMIC AND WATER QUALITY (EUTROPHICATION) MODEL

    EPA Science Inventory

    The Peconic Estuary is located on the eastern end of Long Island, New York. Under the Federal Clean Water Act, the Peconic Estuary was named an "Estuary of National Significance" in 1992. Because of its high concentration of rare, threatened and endangered species and habitats,...

  8. Mapping exchange and residence time in a model of Willapa Bay, Washington, a branching, macrotidal estuary

    E-print Network

    Hickey, Barbara

    estuary N. S. Banas and B. M. Hickey School of Oceanography, University of Washington, Seattle, Washington with every tide, average retention times in the upper third of the estuary are 3­5 weeks. Citation: Banas, N input [Hickey and Banas, 2003] that we do not treat it as part of this series. These estuaries

  9. Photo: TH DeWitt, USEPA EPA's benthic habitat data for Yaquina estuary

    E-print Network

    Wright, Dawn Jeannine

    lower & mid estuary Intertidal submerged aquatic vegetation (seagrass & macroalgae) 1997, 1998, 2004/A HMSC, GP mill (Toledo)whole estuaryIntertidalJune2004 Seagrass cover & shoot density, macroalgae cover density by type, macroalgae cover and volume RM 1, RM 8lower estuary Intertidal & subtidalJuly-Aug2000

  10. A comparative study of carbon dioxide degassing in river-and marine-dominated estuaries

    E-print Network

    Cai, Wei-Jun

    .'' According to this definition, all river mouths and coastal brackish lagoons qualify as estuaries, although adopted the most widely held point of view that considers both river mouths and coastal brackish lagoons to be estuaries. The inclusion of coastal brackish lagoons as estuaries is also consistent with the fact

  11. Sediment Flushing at the Nakdong River Estuary Barrage ; P. Y. Julien, M.ASCE2

    E-print Network

    Julien, Pierre Y.

    accumulated sedi- ments behind estuary barrages. Estuary barrages are typically de- signed to prevent salt-water ; and S. K. Park, M.ASCE3 Abstract: The Nakdong River Estuary Barrage (NREB) prevents salt-water intrusion to annually rebuilding 300 large dams at an estimated cost of $9 billion to replace the worldwide storage loss

  12. A Simple Model of Nitrogen Concentration, Throughput, and Denitrification in Estuaries

    EPA Science Inventory

    The Estuary Nitrogen Model (ENM) is a mass balance model that includes calculation of nitrogen losses within bays and estuaries using system flushing time. The model has been used to demonstrate the dependence of throughput and denitrification of nitrogen in bays and estuaries on...

  13. Lawrence Livermore National Laboratory Annual Report 2006

    SciTech Connect

    Chrzanowski, P; Walter, K

    2007-05-24

    For the Laboratory and staff, 2006 was a year of outstanding achievements. As our many accomplishments in this annual report illustrate, the Laboratory's focus on important problems that affect our nation's security and our researchers breakthroughs in science and technology have led to major successes. As a national laboratory that is part of the Department of Energy's National Nuclear Security Administration (DOE/NNSA), Livermore is a key contributor to the Stockpile Stewardship Program for maintaining the safety, security, and reliability of the nation's nuclear weapons stockpile. The program has been highly successful, and our annual report features some of the Laboratory's significant stockpile stewardship accomplishments in 2006. A notable example is a long-term study with Los Alamos National Laboratory, which found that weapon pit performance will not sharply degrade from the aging effects on plutonium. The conclusion was based on a wide range of nonnuclear experiments, detailed simulations, theoretical advances, and thorough analyses of the results of past nuclear tests. The study was a superb scientific effort. The continuing success of stockpile stewardship enabled NNSA in 2006 to lay out Complex 2030, a vision for a transformed nuclear weapons complex that is more responsive, cost efficient, and highly secure. One of the ways our Laboratory will help lead this transformation is through the design and development of reliable replacement warheads (RRWs). Compared to current designs, these warheads would have enhanced performance margins and security features and would be less costly to manufacture and maintain in a smaller, modernized production complex. In early 2007, NNSA selected Lawrence Livermore and Sandia National Laboratories-California to develop ''RRW-1'' for the U.S. Navy. Design efforts for the RRW, the plutonium aging work, and many other stockpile stewardship accomplishments rely on computer simulations performed on NNSA's Advanced Simulation and Computing (ASC) Program supercomputers at Livermore. ASC Purple and BlueGene/L, the world's fastest computer, together provide nearly a half petaflop (500 trillion operations per second) of computer power for use by the three NNSA national laboratories. Livermore-led teams were awarded the Gordon Bell Prize for Peak Performance in both 2005 and 2006. The winning simulations, run on BlueGene/L, investigated the properties of materials at the length and time scales of atomic interactions. The computing power that makes possible such detailed simulations provides unprecedented opportunities for scientific discovery. Laboratory scientists are meeting the extraordinary challenge of creating experimental capabilities to match the resolution of supercomputer simulations. Working with a wide range of collaborators, we are developing experimental tools that gather better data at the nanometer and subnanosecond scales. Applications range from imaging biomolecules to studying matter at extreme conditions of pressure and temperature. The premier high-energy-density experimental physics facility in the world will be the National Ignition Facility (NIF) when construction is completed in 2009. We are leading the national effort to perform the first fusion ignition experiments using NIF's 192-beam laser and prepare to explore some of the remaining important issues in weapons physics. With scientific colleagues from throughout the nation, we are also designing revolutionary experiments on NIF to advance the fields of astrophysics, planetary physics, and materials science. Mission-directed, multidisciplinary science and technology at Livermore is also focused on reducing the threat posed by the proliferation of weapons of mass destruction as well as their acquisition and use by terrorists. The Laboratory helps this important national effort by providing its unique expertise, integration analyses, and operational support to the Department of Homeland Security. For this vital facet of the Laboratory's national security mission, we are developing advanced technologies, such as

  14. Potential intertidal habitat restoration sites in the Duwamish River estuary

    SciTech Connect

    Tanner, C.D.

    1991-12-01

    Restoration of wetland habitats in highly urbanized areas is generally constrained by scarcity of opportunity, adverse impacts of surrounding land use, and cost. Although areal wetland losses approach 98% in Seattle's Duwamish River estuary, the system continues to support important salmonid runs, as well as a variety of bird and mammal species. Estuarine-dependent organisms are likely limited by quality and quantity of intertidal habitat in the system. Because the long-range, estuary-wide benefit of site-specific mitigation and restoration projects is limited, it is imperative to develop estuary-wide restoration plans. Towards this end, an inventory and analysis of potential intertidal habitat restoration sites has been completed for the Duwamish River estuary. Twenty-four sites, ranging in size from 0.8 to 25 acres were identified and comparative functional potential assessed. The majority of these sites (18) occur in the upper estuary. Two sites are located in Elliott Bay, and four are located near the historic mouth of the river in the vicinity of Harbor Island. Spatial data have been developed in geographic information system (GIS) format. Other site-specific data relative to habitat restoration has also been assembled.

  15. Metals in sediments and benthic organisms in the Mersey estuary

    NASA Astrophysics Data System (ADS)

    Langston, W. J.

    1986-08-01

    Concentrations of twelve metals were determined in sediments, seaweed ( Fucus vesiculosus), winkles ( Littorina littorea), polychaetes ( Nereis diversicolor), suspension feeding bivalves ( Mytilus edulis, Cerastoderma edule) and deposit feeding bivalves ( Macoma balthica, Scrobicularia plana) collected from the Mersey estuary between April 1980 and June 1984. Sediments and organisms in the Mersey are moderately contaminated with most of the metals measured, but mercury concentrations are consistently higher than in other United Kingdom estuaries. Comparisons with other sites in the North West of England indicate that mercury residues in organisms, though primarily dependent on sediment concentrations, are also influenced by complexation with particulate organic matter which reduces the availability of mercury. The biological availability of arsenic in Mersey sediments is similarly influenced by complexation with iron oxyhydroxides. Nereis diversicolor and Macoma balthica are the most suitable indicator species in terms of abundance and widespread distribution along the estuary, and, for the majority of metals, tissue concentrations increase upstream, reflecting corresponding gradients in sediment contamination. However mid-estuarine peaks for tin, chromium copper and nickel in Nereis indicate more localised inputs to the estuary. Correlations between lead in sediments and organisms are poor; it is suggested that hydrophilic alkyl lead compounds may be the predominant biologically available forms. Progressive reductions in mercury contamination in sediments and mercury and lead in organisms have occurred in recent years, which coincide with efforts to reduce inputs of these metals to teh Mersey estuary.

  16. St. Vrain Creek

    USGS Multimedia Gallery

    St. Vrain Creek below Boulder Creek at Hwy 119 near Longmont, CO; Bob Brandle, Cory Stephens, Matt Nicotra, and Kevin Scofield measure discharge and install temporary streamgage replacing nearby damaged streamgage....

  17. St. John's wort

    MedlinePLUS

    ... not native to Australia and long considered a weed, St. John’s wort is now grown there as ... San Juan, Hypereikon, Hyperici Herba, Hypericum perforatum, Klamath Weed, Millepertuis, Millepertuis Perforé, Rosin Rose, Saynt Johannes Wort, ...

  18. St. Louis Encephalitis

    MedlinePLUS

    ... please visit this page: About CDC.gov . Saint Louis Encephalitis St. Louis Encephalitis Home Frequently Asked Questions Prevention Virus Transmission ... Equine Encephalitis West Nile Virus Yellow Fever Saint Louis encephalitis virus (SLEV) is transmitted to humans by ...

  19. St. John's wort

    MedlinePLUS

    ... in the dry ground of roadsides, meadows, and woods. Although not native to Australia and long considered ... of ADHD in children ages 6-17 years. Burning mouth syndrome. Taking St. John’s wort three times ...

  20. How Much Is Another Mammalian Genome Lee A. Newberg and Charles E. Lawrence

    E-print Network

    Newberg, Heidi

    How Much Is Another Mammalian Genome Worth? Lee A. Newberg and Charles E. Lawrence Bioinformatics Institute RECOMB Workshop on Regulatory Genomics, March 26, 2004 #12;Lee A. Newberg & Charles E. Lawrence are highly correlated. #12;Lee A. Newberg & Charles E. Lawrence, page 3 Overview The Questions How much do

  1. Lawrence Livermore National Laboratory Robin L. Newmark, S. Julio Friedmann, A.J. Simon,

    E-print Network

    Keller, Arturo A.

    Lawrence Livermore National Laboratory Robin L. Newmark, S. Julio Friedmann, A.J. Simon, Richard White, S. Carroll LLNL-PRES-411354 Lawrence Livermore National Laboratory, P. O. Box 808, Livermore, CA 94551 This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore

  2. Lawrence Livermore National Laboratory Dan Quinlan and Chunhua Liao and PERI tools

    E-print Network

    Dongarra, Jack

    Lawrence Livermore National Laboratory Dan Quinlan and Chunhua Liao and PERI tools Center for Applied Scientific Computing Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551 This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National

  3. Numerical modeling of circulation in high-energy estuaries: A Columbia River estuary benchmark

    NASA Astrophysics Data System (ADS)

    Kärnä, Tuomas; Baptista, António M.; Lopez, Jesse E.; Turner, Paul J.; McNeil, Craig; Sanford, Thomas B.

    2015-04-01

    Numerical modeling of three-dimensional estuarine circulation is often challenging due to complex flow features and strong density gradients. In this paper the skill of a specific model is assessed against a high-resolution data set, obtained in a river-dominated mesotidal estuary with autonomous underwater vehicles and a shipborne winched profiler. The measurements provide a detailed view of the salt wedge dynamics of the Columbia River estuary. Model skill is examined under contrasting forcing conditions, covering spring freshet and autumn low flow conditions, as well as spring and neap tides. The data set provides a rigorous benchmark for numerical circulation models. This benchmark is used herein to evaluate an unstructured grid circulation model, based on linear finite element and finite volume formulations. Advection of momentum is treated with an Eulerian-Lagrangian scheme. After the model's sensitivity to grid resolution and time step is examined, a detailed skill assessment is provided for the best model configuration. The simulations reproduce the timing and tidal asymmetry of salinity intrusion. Sharp density gradients, however, tend to be smoothed out affecting vertical mixing and gravitational circulation. We show that gravitational salt transport is underestimated in the model, but is partially compensated through tidal effects. The discrepancy becomes most pronounced when the stratification is strongest, i.e., under high river discharge and neap tide conditions.

  4. Astronaut Wendy Lawrence monitors the Protein Crystal Growth experiment

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Astronaut Wendy B. Lawrence, flight engineer and mission specialist for STS-67, scribbles notes on the margin of a checklist while monitoring an experiment on the Space Shuttle Endeavour's middeck. The experiment is the Protein Crystal Growth (PCG), which takes up locker space near the Commercial Materials Dispersion Apparatus Instruments Technology Associates Experiment (CMIX, see decal upper left).

  5. Essential Literacy Partnerships at the South Lawrence East Elementary School

    ERIC Educational Resources Information Center

    Toomey, Mary

    2007-01-01

    Since joining the Coalition of Essential Schools in February 1999, the South Lawrence East Elementary School has used the CES Common Principles as the foundation for enhancing its culture and ensuring student success. To help the teachers meet their literacy goals, the school began a partnership in the spring of 2000 with the Eliot-Pearson Center…

  6. A Useful Renormalization Argument Maury Bramson and Lawrence Gray 1

    E-print Network

    Gray, Lawrence

    A Useful Renormalization Argument Maury Bramson and Lawrence Gray 1 We define a collection authors partially supported by the National Science Foundation. #12; 2 BRAMSON AND GRAY in which], and then developed for more general use in continuous time by Gray and Griffeath [8], Bramson and Gray [4

  7. Management of hazardous wastes Lawrence Livermore National Laboratory

    SciTech Connect

    Jackson, C.S.

    1993-11-01

    Lawrence Livermore National Laboratory (LLNL), during the course of numerous research activities, generates hazardous, radioactive, and mixed (radioactive and hazardous) wastes. The management of these waste materials is highly regulated in the United States (US). This paper focuses on the hazardous waste regulations that limit and prescribe waste management at LLNL.

  8. MICROWAVE PROCESSING OF LUNAR SOIL Lawrence A. Taylor1

    E-print Network

    Taylor, Lawrence A.

    as your tea-water is heated. No lunar simulants exist to study these microwave effects; in fact, previous and microwave into hybrid heating can be used to form various structural and mechanical materials for use bothMICROWAVE PROCESSING OF LUNAR SOIL Lawrence A. Taylor1 and Thomas T. Meek2 The unique properties

  9. Face Recognition: A Hybrid Neural Network Approach Steve Lawrence

    E-print Network

    Giles, C. Lee

    and invariance to minor changes in the image sample, and the convolutional neural network provides for partial, a self-organizing map neural network, and a convolutional neural network. The self-organizing mapFace Recognition: A Hybrid Neural Network Approach Steve Lawrence ¢¡ £¥¤ , C. Lee Giles §¦ , Ah

  10. Lawrence Berkeley Laboratory Institutional Plan FY 1995--2000

    SciTech Connect

    1994-12-01

    This report presents the details of the mission and strategic plan for Lawrence Berkeley Laboratory during the fiscal years of 1995--2000. It presents summaries of current programs and potential changes; critical success factors such as human resources; management practices; budgetary allowances; and technical and administrative initiatives.

  11. LAWRENCE AVENUE UNDERFLOW SEWER SYSTEM. INTERIM REPORT: PLANNING AND CONSTRUCTION

    EPA Science Inventory

    A new and bold concept in design of urban drainage systems was developed as a step forward in the solution of combined sewer overflow problems. A deep tunnel in bed rock about 200 to 250 feet (61 to 76 m) below the surface was designed and constructed for the Lawrence Avenue drai...

  12. Lawrence v Fen Tigers: where now for nuisance?

    E-print Network

    Lees, Emma

    2014-01-01

    The recent decision of the Supreme Court in Lawrence v Fen Tigers 1 is significant, not least for the fact that it is one of few recent decisions of the highest court in relation to the tort of nuisance. In addition to giving general guidance...

  13. Intermediate valence in Yb Intermetallic compounds Jon Lawrence

    E-print Network

    Lawrence, Jon

    1 Intermediate valence in Yb Intermetallic compounds Jon Lawrence University of California, Irvine-based intermetallics. The ground state is that of a heavy mass Fermi liquid. The d.c. and optical conductivity reflect. Talk at LBL, 12 April 2006 #12;2 Intermediate Valence Compounds CeSn3 Fermi liquid (FL) YbAgCu4, Yb

  14. Nonparametric Regression in Exponential Families Lawrence D. Brown1

    E-print Network

    Brown, Lawrence D.

    Nonparametric Regression in Exponential Families Lawrence D. Brown1 , T. Tony Cai1 and Harrison H. Zhou2 University of Pennsylvania and Yale University Abstract Most results in nonparametric regression we consider nonparametric regression in exponential families with the main focus on the natural

  15. Nonparametric Regression in Exponential Families Lawrence D. Brown1

    E-print Network

    Zhou, Harrison Huibin

    Nonparametric Regression in Exponential Families Lawrence D. Brown1 , T. Tony Cai2 and Harrison H. Zhou3 University of Pennsylvania and Yale University Abstract Most results in nonparametric regression we consider nonparametric regression in exponential families which include, for example, Poisson

  16. Waste management study: Process development at Lawrence Livermore National Laboratory

    SciTech Connect

    Not Available

    1984-12-01

    This report presents the results of an evaluation of the present Toxic Waste Control Operations at the Lawrence Livermore National Laboratory, evaluates the technologies most applicable to the treatment of toxic and hazardous wastes and presents conceptual designs of processes for the installation of a new decontamination and waste treatment facility (DWTF) for future treatment of these wastes.

  17. LAWRENCE AVENUE UNDERFLOW SEWER SYSTEM: MONITORING AND EVALUATION

    EPA Science Inventory

    A new and bold concept in design of urban drainage systems was developed as a step forward in the solution of combined sewer overflow problems. A deep tunnel in bed rock about 200 to 250 feet (61 to 76 m) below the surface was designed and constructed for the Lawrence Avenue drai...

  18. Using Neural Networks to Forecast Stock Market Prices Ramon Lawrence

    E-print Network

    Lawrence, Ramon

    Using Neural Networks to Forecast Stock Market Prices Ramon Lawrence Department of Computer Science on the application of neural networks in forecasting stock market prices. With their ability to discover patterns in nonlinear and chaotic systems, neural networks offer the ability to predict market directions more

  19. Annual environmental monitoring report of the Lawrence Berkeley Laboratory, 1986

    SciTech Connect

    Schleimer, G.E.

    1987-04-01

    The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data for 1986 are presented and general trends are discussed. Topics include radiation monitoring, wastewater discharge monitoring, dose distribution estimates, and ground water monitoring. 9 refs., 8 figs., 20 tabs.

  20. Copyright in the Balance: LJ Talks with Lawrence Lessig.

    ERIC Educational Resources Information Center

    Albanese, Andrew Richard

    2002-01-01

    Discusses copyright issues of interest to librarians with Lawrence Lessig, a legal scholar on copyright, technology, and the Constitution. Topics include Eldred v. Ashcroft; copyright extensions; balancing interests of copyright owners with future creators and the public; privacy, fair use, and public domain; and the Digital Millennium Copyright…

  1. DASLL: design automation system at Lawrence Livermore. User's reference manual

    SciTech Connect

    Magnuson, W.G. Jr.; Willett, G.W.

    1980-04-01

    This manual shows how to use the DASLL system to lay out printed circuit boards using the OCTOPUS CDC 7600 computer system and other equipment at Lawrence Livermore Laboratory. This information will also be found very useful for those converting or analyzing the DASLL system.

  2. Environmental monitoring at the Lawrence Livermore Laboratory. 1979 annual report

    SciTech Connect

    Silver, W.J.; Lindeken, C.L.; White, J.H.; Buddemeir, R.W.

    1980-04-25

    Information on monitoring activities is reported in two sections for EDB/ERA/INIS. The first section covers all information reported except Appendix D, which gives details of sampling and analytical procedures for environmental monitoring used at Lawrence Livermore Laboratory. A separate abstract was prepared for Appendix D. (JGB)

  3. LUNAR MINERALS James Papike, Lawrence Taylor, and Steven Simon

    E-print Network

    Rathbun, Julie A.

    LUNAR MINERALS James Papike, Lawrence Taylor, and Steven Simon The lunar rocks described--make it easy to distinguish them from terrestrial rocks. However, the minerals that make up lunar rocks are (with a few notable exceptions) minerals that are also found on Earth. Both lunar and terrestrial rocks

  4. Jacob Lawrence's "The Migration Series": Art as Narrative History

    ERIC Educational Resources Information Center

    Laney, James D.

    2007-01-01

    Because art is a reflection of cultural heritage, a natural affinity exists between art and social studies. In Jacob Lawrence's "The Migration Series," art serves as narrative history, with visual images telling the story of the Great Migration, a movement of African American people from the South to the North around World War I. Social studies…

  5. Building Footprints (Shapefile) of University of Kansas, Lawrence Campus

    E-print Network

    Houser, Rhonda

    2011-02-18

    Data layer geneated with Intention to have basic building dataset for data analysis and generation of maps, for Lawrence Campus of the University of Kansas. Building outlines were digitized using ArcMap in ca. 2007 from aerial photograph to create...

  6. PHOTOCOPY OF HISTORIC PHOTOGRAPH, "LAWRENCE LEVERING BECKEL (BRIDGE BUILT BY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PHOTOCOPY OF HISTORIC PHOTOGRAPH, "LAWRENCE LEVERING BECKEL (BRIDGE BUILT BY HIM AND HIS FATHER, CHAS. N. BECKEL AT EASTON)," original ca. 1885, photographer unknown. Collection of Historic Bethlehem Inc., Bethlehem, PA, Negative Nos. 3550 or 4504. - Walnut Street Bridge, Formerly spanning Saucon Creek, Hellertown, Northampton County, PA

  7. The frictional nature of tidal propagation in channelized estuaries, with applications to a tidal marsh in Delaware

    E-print Network

    Kirby, James T.

    The frictional nature of tidal propagation in channelized estuaries, with applications to a tidal the variable width of the estuary with rising and falling tides. A field study was conducted on the main of an estuary dominated by tidal variations in channel depth, rather than variations in estuary width

  8. Impact of the Clean Water Act on the levels of toxic metals in urban estuaries: The Hudson River estuary revisited

    SciTech Connect

    Sanudo-Wilhelmy, S.A.; Gill, G.A.

    1999-10-15

    To establish the impact of the Clean Water Act on the water quality of urban estuaries, dissolved trace metals and phosphate concentrations were determined in surface waters collected along the Hudson River estuary between 1995 and 1997 and compared with samples collected in the mid-1970s by Klinkhammer and Bender. The median concentrations along the estuary have apparently declined 36--56% for Cu, 55--89% for Cd, 53--85% for Ni, and 53--90% for Zn over a period of 23 years. These reductions appear to reflect improvements in controlling discharges from municipal and industrial wastewater treatment plants since the Clean Water Act was enacted in 1972. In contrast, levels of dissolved nutrients (PO{sub 4}) have remained relatively constant during the same period of time, suggesting that wastewater treatment plant improvements in the New York/New Jersey Metropolitan area have not been as effective at reducing nutrient levels within the estuary. While more advanced wastewater treatment could potentially reduce the levels of Ag and PO{sub 4} along the estuary, these improvements would have a more limited effect on the levels of other trace metals.

  9. The geomorphology of UK estuaries: The role of geological controls, antecedent conditions and human activities

    NASA Astrophysics Data System (ADS)

    Pye, Kenneth; Blott, Simon J.

    2014-10-01

    This paper provides an overview of the geomorphological characteristics of UK estuaries and the factors which control them. Many of the features included in previous classifications of UK estuaries are not true estuaries since they do not possess significant river influence. The features considered in this paper to be 'true' estuaries are divided into 'restricted entrance' and 'unrestricted entrance' types on the grounds that the size and geometry of the estuary mouth exerts a critical influence on water levels, tidal currents, wave action, sediment transport and morphological evolution. An estuary which has a wide mouth, narrows and becomes shallower towards the head is likely to be flood dominated, especially if it has a large tidal range, whereas an estuary which has a narrow mouth and widens and/or becomes deeper towards the head is more likely to display ebb dominance, especially if it has a relatively small tidal range. Wide-mouthed estuaries are influenced to a greater degree by wave processes than estuaries with a narrow mouth. Previous authors have hypothesised that estuaries may maintain a state of dynamic equilibrium through alternating periods of flood and ebb dominance, but it is concluded that there is presently no substantive evidence to support this hypothesis. UK estuaries have been affected to varying degrees by embanking, land claim, dredging, sea wall breaching and managed realignment. Some estuaries have adjusted quickly to such perturbations, but others continue to show progressive change, either sedimentary infilling or erosion and sediment loss. The quantification of estuary morphometry, identification of change over time, and testing of hypotheses regarding the morphodynamics and stability of estuaries requires adequate bathymetric/topographic, hydrodynamic and sediment data. At present, such data are available for relatively few UK estuaries.

  10. Methane in surface waters of Oregon estuaries and rivers

    SciTech Connect

    de Angelis, M.A.; Lilley, M.D. )

    1987-05-01

    Methane concentrations in surface waters of Oregon rivers and estuaries were measured over a four-year period. Geographic variations in riverine CH{sub 4} were observed. Results from undisturbed forest streams indicate that rivers can contain high natural levels of CH{sub 4} not attributable to pollution. Lateral diffusion and runoff from saturated forest and fertilized agricultural soils may be important in determining methane levels in rivers. Methane concentrations in well-flushed estuaries appear to be controlled mainly by mixing between high CH{sub 4}-containing river water and low CH{sub 4}-containing seawater endmembers. Rivers and estuaries were found to be sources of methane to the atmosphere. Calculated daily fluxes to the atmosphere ranged from 1.2 to 71 mg CH{sub 4} sq m for rivers and from 0.04 to 21 mg CH{sub 4} sq m for estuarine samples. 24 refs., 4 figs., 3 tabs.

  11. Origin of carbon in organic matter in the Neva estuary.

    PubMed

    Golubkov, S M; Tiunov, A V

    2015-11-01

    Analysis of the isotopic composition of tissues of representatives of zoobenthos and organic matter of seston have shown that the major part of carbon participating in the biological turnover in the ecosystem of the upper part of the Neva estuary is of terrestrial origin. Obviously, it is discharged from the lake drainage area to the Lake Ladoga-Neva-Neva estuary system. The results have revealed an important role in aquatic ecosystems of the humid zone of allochthonous humic substances creating a supplementary stock of nutrients and enhancing the productivity of ecosystems. Detailed investigations of the role of various forms of allochthonous organic compounds of terrestrial origin are necessary for elaboration of efficient measures for alleviation of eutrophication of the Neva estuary. PMID:26725237

  12. Radium isotopes in the Orinoco estuary and Eastern Caribbean Sea

    SciTech Connect

    Moore, W.S.; Todd, J.F. )

    1993-02-15

    Radium isotopes provide a means of identifying the source of freshened waters in the ocean and determining the time elapsed since these waters were in the estuary. The authors present evidence that during April, waters from the Amazon mixing zone pass within 50 km of the mouth of the Orinoco River. These Amazon waters are characterized by a lower [sup 228]Ra/[sup 226]Ra activity ratio (AR) than are waters from the Orinoco at similar salinities. During autumn, the increased discharge of the Orinoco displaces the freshened Amazon waters seaward, yet the two can be distinguished clearly. Within the Caribbean Sea, waters of Orinoco origin carry a characteristic radium signature including excess activities of [sup 224]Ra. This isotope may be used to estimate the time elapsed since the waters were removed from contact with sediments. Current speeds based on [sup 224]Ra dating ranged from 15 to 33 cm/s during April. The radium isotopes also provide an assessment of sediment mixing in the estuary. During low discharge (April), considerable mixing of older sediment by physical or biological processes or dredging maintained high activities of [sup 228]Ra in the estuary and produced the highest [sup 228]Ra/[sup 226]Ra AR's yet measured in any estuary. During high discharge (September), a large fraction of the [sup 228]Ra was derived from desorption from fresh sediment rather than mixing of older sediments. Activities of [sup 224]Ra were high in the estuary during both high and low discharge, indicating that considerable mixing of recently introduced sediment must occur during each period. During April, [sup 224]Ra and [sup 228]Ra activities in the water were about equal, indicating that most of the sediment being resuspended had been stored in the estuary long enough to reestablish radioactive equilibrium in the [sup 232]Th decay series (i.e., 20 years). 19 refs., 11 figs., 3 tabs.

  13. Mud transport in the Microtidal San Jacinto Estuary

    NASA Astrophysics Data System (ADS)

    Salehi, M.; Strom, K. B.

    2012-12-01

    The overall objective of this research is to better understand the sediment transport processes in the microtidal San Jacinto Estuary (near Houston, TX) under variable hydrologic conditions. A numerical modeling approach is selected to answer the main question of; how will changes in freshwater input change the sedimentation pattern of the region? In this computational work, no new numerical method or code is developed, but rather an existing technology (MIKE 3D developed by DHI) is used to build a virtual San Jacinto Estuary laboratory where boundary conditions could be applied and altered to the domain to observe the general functional response of the system. Two synthetic freshwater inflows, simulating dry and wet conditions, were used in the numerical modeling experiments. Simulations showed that change in freshwater inflow has major impact on the salinity magnitude within the estuary. In dry conditions, the 5 ppt isohaline traveled all the way upstream of Morgans Point, almost to the confluence of San Jacinto River with Buffalo Bayou. During the extreme wet weather conditions, the 5 ppt isohaline of the surface water was pushed almost as far as Galveston Island. Overall erosion and deposition pattern showed little change between extreme dry and wet years. In general, part of the shallow areas experienced erosion whereas deeper parts of the estuary were under deposition. High freshwater inflow caused around 30% higher deposition in some parts of the channel compared with the low freshwater. Furthermore, examining the mass balance within the whole San Jacinto Estuary showed that around 28% of the input sediment was flushed out during the wet season. But in dry season, not only no sediment left the domain but also it received around 17% of the total available sediment within the estuary from the shelf.

  14. Mud transport in the Microtidal San Jacinto Estuary

    NASA Astrophysics Data System (ADS)

    Salehi, M.

    2013-12-01

    The overall objective of this research is to better understand the sediment transport processes in the microtidal San Jacinto Estuary (near Houston, TX) under variable hydrologic conditions. A numerical modeling approach is selected to answer the main question of; how will changes in freshwater input change the sedimentation pattern of the region? In this computational work, no new numerical method or code is developed, but rather an existing technology (MIKE 3D developed by DHI) is used to build a virtual San Jacinto Estuary laboratory where boundary conditions could be applied and altered to the domain to observe the general functional response of the system. Two synthetic freshwater inflows, simulating dry and wet conditions, were used in the numerical modeling experiments. Simulations showed that change in freshwater inflow has major impact on the salinity magnitude within the estuary. In dry conditions, the 5 ppt isohaline traveled all the way upstream of Morgans Point, almost to the confluence of San Jacinto River with Buffalo Bayou. During the extreme wet weather conditions, the 5 ppt isohaline of the surface water was pushed almost as far as Galveston Island. Overall erosion and deposition pattern showed little change between extreme dry and wet years. In general, part of the shallow areas experienced erosion whereas deeper parts of the estuary were under deposition. High freshwater inflow caused around 30% higher deposition in some parts of the channel compared with the low freshwater. Furthermore, examining the mass balance within the whole San Jacinto Estuary showed that around 28% of the input sediment was flushed out during the wet season. But in dry season, not only no sediment left the domain but also it received around 17% of the total available sediment within the estuary from the shelf.

  15. Impacts of pesticides in a Central California estuary.

    PubMed

    Anderson, Brian; Phillips, Bryn; Hunt, John; Siegler, Katie; Voorhees, Jennifer; Smalling, Kelly; Kuivila, Kathy; Hamilton, Mary; Ranasinghe, J Ananda; Tjeerdema, Ron

    2014-03-01

    Recent and past studies have documented the prevalence of pyrethroid and organophosphate pesticides in urban and agricultural watersheds in California. While toxic concentrations of these pesticides have been found in freshwater systems, there has been little research into their impacts in marine receiving waters. Our study investigated pesticide impacts in the Santa Maria River estuary, which provides critical habitat to numerous aquatic, terrestrial, and avian species on the central California coast. Runoff from irrigated agriculture constitutes a significant portion of Santa Maria River flow during most of the year, and a number of studies have documented pesticide occurrence and biological impacts in this watershed. Our study extended into the Santa Maria watershed coastal zone and measured pesticide concentrations throughout the estuary, including the water column and sediments. Biological effects were measured at the organism and community levels. Results of this study suggest the Santa Maria River estuary is impacted by current-use pesticides. The majority of water samples were highly toxic to invertebrates (Ceriodaphnia dubia and Hyalella azteca), and chemistry evidence suggests toxicity was associated with the organophosphate pesticide chlorpyrifos, pyrethroid pesticides, or mixtures of both classes of pesticides. A high percentage of sediment samples were also toxic in this estuary, and sediment toxicity occurred when mixtures of chlorpyrifos and pyrethroid pesticides exceeded established toxicity thresholds. Based on a Relative Benthic Index, Santa Maria estuary stations where benthic macroinvertebrate communities were assessed were degraded. Impacts in the Santa Maria River estuary were likely due to the proximity of this system to Orcutt Creek, the tributary which accounts for most of the flow to the lower Santa Maria River. Water and sediment samples from Orcutt Creek were highly toxic to invertebrates due to mixtures of the same pesticides measured in the estuary. This study suggests that the same pyrethroid and organophosphate pesticides that have been shown to cause water and sediment toxicity in urban and agriculture water bodies throughout California, have the potential to affect estuarine habitats. The results establish baseline data in the Santa Maria River estuary to allow evaluation of ecosystem improvement as management initiatives to reduce pesticide runoff are implemented in this watershed. PMID:24464329

  16. Physical biological coupling in the Pearl River Estuary

    NASA Astrophysics Data System (ADS)

    Harrison, Paul J.; Yin, Kedong; Lee, J. H. W.; Gan, Jianping; Liu, Hongbin

    2008-07-01

    The Pearl River Estuary is a subtropical estuary and the second largest in China based on discharge volume from the Pearl River. Processes in the estuary vary spatially and temporally (wet vs dry season). In the dry season at the head of the estuary, hypoxic and nearly anoxic conditions occur and NH 4 reaches >600 ?M, NO 3 is ˜300 ?M and nitrite is ˜60 ?M indicating that nitrification and denitrification may be important dry season processes in the region extending 40 km upstream of the Humen outlet. There are very few biological studies conducted in this upper section of the estuary in either the dry or wet seasons and hence there is a need for further research in this region of the river. In the wet season, the salinity wedge extends to the Hongqimen outlet and oxygen is low (35-80% saturation). Nitrate is ˜100 ?M, silicate ˜140 ?M; and phosphate is relatively low at ˜0.5 ?M, yielding an N:P ratio up to ˜200:1 in summer. Nutrients decrease in the lower estuary and primary productivity may become potentially P-limited. Eutrophication is not as severe as one would expect from the nutrient inputs from the Pearl River and from Hong Kong's sewage discharge. This estuary shows a remarkable capacity to cope with excessive nutrients. Physical processes such as river discharge, tidal flushing, turbulent dispersion, wind-induced mixing, and estuarine circulation play an important role in controlling the production and accumulation of algal blooms and the potential occurrence of hypoxia. Superimposed on the physical processes of the estuary are the chemical and biological processes involved in the production of the bloom. For example, the 100N:1P ratio indicates that P potentially limits the amount of algal biomass (and potential biological oxygen demand) in summer. While extended periods of hypoxia are rare in Hong Kong waters, episodic events have been reported to occur during late summer due to factors such as low wind, high rainfall and river discharge which result in strong density stratification that significantly dampens vertical mixing processes. Nutrient loads are likely to change over the next several decades and monitoring programs are essential to detect the response of the ecosystem due to the future changes in nutrient loading and the ratio of nutrients.

  17. Research, Monitoring, and Evaluation for the Federal Columbia River Estuary Program

    SciTech Connect

    Johnson, Gary E.; Diefenderfer, Heida L.; Ebberts, Blaine D.; Tortorici, Cathy; Yerxa, Tracey; Leary, J.; Skalski, John R.

    2008-02-05

    The purpose ofthis document is to describe research, monitoring, and evaluation (RME) for the Federal Columbia River Estuary Program. The intent of this RME effort is to provide data and information to evaluate progress toward meeting program goals and objectives and support decision-making in the Estuary Program. The goal of the Estuary Program is to understand, conserve, and restore the estuary ecosystem to improve the performance of listed salmonid populations. The Estuary Program has five general objectives, designed to fulfill the program goal, as follows. 1. Understand the primary stressors affecting ecosystem controlling factors, such as ocean conditions and invasive species. 2. Conserve and restore factors controlling ecosystem structures and processes, such as hydrodynamics and water quality. 3. Increase the quantity and quality of ecosystem structures, i.e., habitats, juvenile salmonids use during migration through the estuary. 4. Maintain the food web to benefit salmonid performance. 5. Improve salmonid performance in terms of life history diversity, foraging success, growth, and survival. The goal of estuary RME is to provide pertinent and timely research and monitoring information to planners, implementers, and managers of the Estuary Program. In conclusion, the estuary RME effort is designed to meet the research and monitoring needs of the estuary Program using an adaptive management process. Estuary RME's success and usefulness will depend on the actual conduct of adaptive management, as embodied in the objectives, implrementation, data, reporting, and synthesis, evaluation, and decision-making described herein.

  18. Large-scale spatial patterns in estuaries: estuarine macrobenthic communities in the Schelde estuary, NW Europe

    NASA Astrophysics Data System (ADS)

    Ysebaert, T.; Herman, P. M. J.; Meire, P.; Craeymeersch, J.; Verbeek, H.; Heip, C. H. R.

    2003-05-01

    Few macrobenthic studies have dealt simultaneously with the two major gradients in estuarine benthic habitats: the salinity gradient along the estuary (longitudinal) and the gradients from high intertidal to deep subtidal sites (vertical gradient). In this broad-scale study, a large data set (3112 samples) of the Schelde estuary allowed a thorough analysis of these gradients, and to relate macrobenthic species distributions and community structure to salinity, depth, current velocities and sediment characteristics. Univariate analyses clearly revealed distinct gradients in diversity, abundance, and biomass along the vertical and longitudinal gradients. In general, highest diversity and biomass were observed in the intertidal, polyhaline zone and decreased with decreasing salinity. Abundance did not show clear trends and varied between spring and autumn. In all regions, very low values for all measures were observed in the subtidal depth strata. Abundance in all regions was dominated by both surface deposit feeders and sub-surface deposit feeders. In contrast, the biomass of the different feeding guilds showed clear gradients in the intertidal zone. Suspension feeders dominated in the polyhaline zone and showed a significant decrease with decreasing salinity. Surface deposit feeders and sub-surface deposit feeders showed significantly higher biomass values in the polyhaline zone as compared with the mesohaline zone. Omnivores showed an opposite trend. Multivariate analyses showed a strong relationship between the macrobenthic assemblages and the predominant environmental gradients in the Schelde estuary. The most important environmental factor was depth, which reflected also the hydrodynamic conditions (current velocities). A second gradient was related to salinity and confirms the observations from the univariate analyses. Additionally, sediment characteristics (mud content) explained a significant part of the macrobenthic community structure not yet explained by the two other main gradients. The different assemblages are further described in terms of indicator species and abiotic characteristics. The results showed that at a large, estuarine scale a considerable fraction of the variation in abundance and biomass of the benthic macrofauna correlated very well with environmental factors (depth, salinity, tidal current velocity, sediment composition).

  19. Abandoned Channel Fill Sequences in Tidal Estuaries

    NASA Astrophysics Data System (ADS)

    Gray, A. B.; Pasternack, G. B.; Goni, M. A.; Watson, E. B.

    2014-12-01

    This study proposes a modification of the current model for abandoned channel fill stratigraphy produced in unidirectional flow river reaches to incorporate seasonal tidal deposition. Evidence supporting this concept came from a study of two consecutive channel abandonment sequences in Ropers Slough of the lower Eel River Estuary in northern California. Aerial photographs showed that Ropers Slough was abandoned around 1943, reoccupied after the 1964 flood, and abandoned again in 1974 with fill continuing to the present. Planform geomorphic characteristics derived from these images were used in conjunction with sub-cm resolution stratigraphic analyses to describe the depositional environment processes and their resultant sedimentary deposits. Results showed that both abandonment sequences recorded quasi-annual scale fluvial/tidal deposition couplets. In both cases tidal deposits contained very little sand, and were higher in organic and inorganic carbon content than the sandier fluvial through-flow deposits. However, the two abandonment fills differed significantly in terms of the temporal progression of channel narrowing and fluvial sediment deposition characteristics. The first abandonment sequence led to a more rapid narrowing of Ropers Slough and produced deposits with a positive relationship between grain size/deposit thickness and discharge. The second abandonment resulted in a much slower narrowing of Ropers Slough and generally thinner fluvial deposits with no clear relationship between grain size/deposit thickness and discharge. The ?13C values and organic nitrogen to organic carbon ratios of deposits from the first phase overlapped with Eel River suspended sediment characteristics found for low flows (1-5 times mean discharge), while those of the second phase were consistent suspended sediment from higher flows (7-10 times mean discharge). The abandoned channel fill sequences appeared to differ due to the topographic steering of bed sediment transport and deposition previously identified in rivers experiencing only unidirectional flow, while also expressing the seasonal dichotomy of fluvial and tidal deposits.

  20. APPENDIX C - ADDITIONAL INFORMATION ON FLUSHING IN ESTUARIES

    EPA Science Inventory

    Water residence time is an important determinant of the sensitivity of the response of estuaries and other water bodies to nutrient loading. A variety of terms such as residence time, flushing time, transit time, turnover time, and age are used to describe time scales for transpo...