Sample records for affect aquatic biota

  1. Pesticides in stream sediment and aquatic biota: distribution, trends, and governing factors

    USGS Publications Warehouse

    Nowell, Lisa H.; Capel, Peter D.

    1999-01-01

    More than 20 years after the ban of DDT and other organochlorine pesticides, pesticides continue to be detected in air, rain, soil, surface water, bed sediment, and aquatic and terrestrial biota throughout the world. Recent research suggests that low levels of some of these pesticides may have the potential to affect the development, reproduction, and behavior of fish and wildlife, and possibly humans. Pesticides in Stream Sediment and Aquatic Biota: Distribution, Trends, and Governing Factors assesses the occurrence and behavior of pesticides in bed sediment and aquatic biota-the two major compartments of the hydrologic system where organochlorine pesticides are most likely to accumulate. This book collects, for the first time, results from several hundred monitoring studies and field experiments, ranging in scope from individual sites to the entire nation. Comprehensive tables provide concise summaries of study locations, pesticides analyzed, and study outcomes. Comprehensive and extensively illustrated, Pesticides in Stream Sediment and Aquatic Biota: Distribution, Trends, and Governing Factors evaluates the sources, environmental fate, geographic distribution, and long-term trends of pesticides in bed sediment and aquatic biota. The book focuses on organochlorine pesticides, but also assesses the potential for currently used pesticides to be found in bed sediment and aquatic biota. Topics covered in depth include the effect of land use on pesticide occurrence, mechanisms of pesticide uptake and accumulation by aquatic biota, and the environmental significance of observed levels of pesticides in stream sediment and aquatic biota.

  2. Biota connect aquatic habitats throughout freshwater ecosystem mosaics

    USGS Publications Warehouse

    Schofield, Kate A.; Alexander, Laurie C.; Ridley, Caroline E.; Vanderhoof, Melanie; Fritz, Ken M.; Autrey, Bradley; DeMeester, Julie; Kepner, William G.; Lane, Charles R.; Leibowitz, Scott; Pollard, Amina I.

    2018-01-01

    Freshwater ecosystems are linked at various spatial and temporal scales by movements of biota adapted to life in water. We review the literature on movements of aquatic organisms that connect different types of freshwater habitats, focusing on linkages from streams and wetlands to downstream waters. Here, streams, wetlands, rivers, lakes, ponds, and other freshwater habitats are viewed as dynamic freshwater ecosystem mosaics (FEMs) that collectively provide the resources needed to sustain aquatic life. Based on existing evidence, it is clear that biotic linkages throughout FEMs have important consequences for biological integrity and biodiversity. All aquatic organisms move within and among FEM components, but differ in the mode, frequency, distance, and timing of their movements. These movements allow biota to recolonize habitats, avoid inbreeding, escape stressors, locate mates, and acquire resources. Cumulatively, these individual movements connect populations within and among FEMs and contribute to local and regional diversity, resilience to disturbance, and persistence of aquatic species in the face of environmental change. Thus, the biological connections established by movement of biota among streams, wetlands, and downstream waters are critical to the ecological integrity of these systems. Future research will help advance our understanding of the movements that link FEMs and their cumulative effects on downstream waters.

  3. Pharmaceuticals in biota in the aquatic environment: analytical methods and environmental implications.

    PubMed

    Huerta, B; Rodríguez-Mozaz, S; Barceló, D

    2012-11-01

    The presence of pharmaceuticals in the aquatic environment is an ever-increasing issue of concern as they are specifically designed to target specific metabolic and molecular pathways in organisms, and they may have the potential for unintended effects on nontarget species. Information on the presence of pharmaceuticals in biota is still scarce, but the scientific literature on the subject has established the possibility of bioaccumulation in exposed aquatic organisms through other environmental compartments. However, few studies have correlated both bioaccumulation of pharmaceutical compounds and the consequent effects. Analytical methodology to detect pharmaceuticals at trace quantities in biota has advanced significantly in the last few years. Nonetheless, there are still unresolved analytical challenges associated with the complexity of biological matrices, which require exhaustive extraction and purification steps, and highly sensitive and selective detection techniques. This review presents the trends in the analysis of pharmaceuticals in aquatic organisms in the last decade, recent data about the occurrence of these compounds in natural biota, and the environmental implications that chronic exposure could have on aquatic wildlife.

  4. Use of the Biotic Ligand Model to predict metal toxicity to aquatic biota in areas of differing geology

    USGS Publications Warehouse

    Smith, Kathleen S.

    2005-01-01

    This work evaluates the use of the biotic ligand model (BLM), an aquatic toxicity model, to predict toxic effects of metals on aquatic biota in areas underlain by different rock types. The chemical composition of water, soil, and sediment is largely derived from the composition of the underlying rock. Geologic source materials control key attributes of water chemistry that affect metal toxicity to aquatic biota, including: 1) potentially toxic elements, 2) alkalinity, 3) total dissolved solids, and 4) soluble major elements, such as Ca and Mg, which contribute to water hardness. Miller (2002) compiled chemical data for water samples collected in watersheds underlain by ten different rock types, and in a mineralized area in western Colorado. He found that each rock type has a unique range of water chemistry. In this study, the ten rock types were grouped into two general categories, igneous and sedimentary. Water collected in watersheds underlain by sedimentary rock has higher mean pH, alkalinity, and calcium concentrations than water collected in watersheds underlain by igneous rock. Water collected in the mineralized area had elevated concentrations of calcium and sulfate in addition to other chemical constituents. Miller's water-chemistry data were used in the BLM (computer program) to determine copper and zinc toxicity to Daphnia magna. Modeling results show that waters from watersheds underlain by different rock types have characteristic ranges of predicted LC 50 values (a measurement of aquatic toxicity) for copper and zinc, with watersheds underlain by igneous rock having lower predicted LC 50 values than watersheds underlain by sedimentary rock. Lower predicted LC 50 values suggest that aquatic biota in watersheds underlain by igneous rock may be more vulnerable to copper and zinc inputs than aquatic biota in watersheds underlain by sedimentary rock. For both copper and zinc, there is a trend of increasing predicted LC 50 values with increasing dissolved

  5. Recent changes in aquatic biota in subarctic Fennoscandia - the role of global and local environmental variables

    NASA Astrophysics Data System (ADS)

    Weckström, Jan; Leppänen, Jaakko; Sorvari, Sanna; Kaukolehto, Marjut; Weckström, Kaarina; Korhola, Atte

    2013-04-01

    The Arctic, representing a fifth of the earth's surface, is highly sensitive to the predicted future warming and it has indeed been warming up faster than most other regions. This makes the region critically important and highlights the need to investigate the earliest signals of global warming and its impacts on the arctic and subarctic aquatic ecosystems and their biota. It has been demonstrated that many Arctic freshwater ecosystems have already experienced dramatic and unpreceded regime shifts during the last ca. 150 years, primarily driven by climate warming. However, despite the indisputable impact of climate-related variables on freshwater ecosystems other, especially local-scale catchment related variables (e.g. geology, vegetation, human activities) may override the climate signal and become the primary factor in shaping the structure of aquatic ecosystems. Although many studies have contributed to an improved understanding of limnological and hydrobiological features of Artic and subarctic lakes, much information is still needed especially on the interaction between the biotic and abiotic components, i.e. on factors controlling the food web dynamics in these sensitive aquatic ecosystems. This is of special importance as these lakes are of great value in water storage, flood prevention, and maintenance of biodiversity, in addition to which they are vital resources for settlement patterns, food production, recreation, and tourism. In this study we compare the pre-industrial sediment assemblages of primary producers (diatoms and Pediastrum) and primary consumers (cladoceran and chironomids) with their modern assemblages (a top-bottom approach) from 50 subarctic Fennoscandian lakes. We will evaluate the recent regional pattern of changes in aquatic assemblages, and assess how coherent the lakes' responses are across the subarctic area. Moreover, the impact of global (e.g. climate, precipitation) and local (e.g. lake and its catchment characteristics) scale

  6. Responses of selected aquatic biota to discharges from Colbert Steam Plant, Tennessee River, 1978 and 1979

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dycus, D.L.; Harned, R.D.; Laborde, S.M.

    1981-06-01

    Results of studies of hydrothermodynamics, water quality, nonfisheries and fisheries biology, supplemented by water chemistry, phytoplankton, periphyton, zooplankton, and benthic macroinvertebrate collections are presented and evaluated. The objective was to examine the effects of thermal discharges from the Colbert Steam Electric Plant, situated in northwest Alabama on Pickwick Reservoir of the Tennessee River, on the aquatic biota of the Tennessee River. (ACR)

  7. Responses of selected aquatic biota to discharges from Colbert Steam Plant, Tennessee River, 1978 and 1979. Volume 2, appendices

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1979-01-01

    Results of studies of hydrothermodynamics, water quality, nonfisheries and fisheries biology, supplemented by water chemistry, phytoplankton, periphyton, zooplankton, and benthic macroinvertebrate collections are presented. The objective was to examine the effects of thermal discharges from the Colbert Steam Electric Plant, situated in northwest Alabama on Pickwick Reservoir of the Tennessee River, on the aquatic biota of the Tennessee River. (ACR)

  8. Trace elements and organic compounds in streambed sediment and aquatic biota from the Sacramento River Basin, California, October and November 1995

    USGS Publications Warehouse

    MacCoy, Dorene E.; Domagalski, Joseph L.

    1999-01-01

    Elevated levels of trace elements and hydrophobic organic compounds were detected in streambed sediments and aquatic biota [Asiatic clam (Corbicula fluminea) or bottom-feeding fish] of the Sacramento River Basin, California, during October and November 1995. Trace elements detected included cadmium, copper, mercury, lead, and zinc. Elevated levels of cadmium, copper, and zinc in the upper Sacramento River are attributed to a mining land use, and elevated levels of zinc and lead in an urban stream, and possibly in the lower Sacramento River, are attributed to urban runoff processes. Elevated levels of mercury in streambed sediment are attributed to either past mercury mining or to the use of mercury in past gold mining operations. Mercury mining was an important land use within the Coast Ranges in the past and gold mining was an important land use of the Sierra Nevada in the past. Mercury was the only trace element found in elevated levels in the tissue of aquatic biota, and those levels also could be attributed to either mining or urban runoff. Hydrophobic organic compounds also were detected in streambed sediments and aquatic biota. The most frequently detected compounds were DDT and its breakdown products, dieldrin, oxychlordane, and toxaphene. Differences were found in the types of compounds detected at agricultural sites and the urban site. Although both types of sites had measurable concentrations of DDT or its breakdown products, the urban site also had measurable concentrations of pesticides used for household pest control. Few semivolatile compounds were detected in the streambed sediments of any site. The semivolatile compound p-cresol, a coal-tar derivative associated with road maintenance, was found in the highest concentration.

  9. Concentration of 129I in aquatic biota collected from a lake adjacent to the spent nuclear fuel reprocessing plant in Rokkasho, Japan.

    PubMed

    Ueda, Shinji; Kakiuchi, Hideki; Hasegawa, Hidenao; Kawamura, Hidehisa; Hisamatsu, Shun'ichi

    2015-11-01

    The spent nuclear fuel reprocessing plant in Rokkasho, Japan, has been undergoing final testing since March 2006. During April 2006-October 2008, that spent fuel was cut and chemically processed, the plant discharged (129)I into the atmosphere and coastal waters. To study (129)I behaviour in brackish Lake Obuchi, which is adjacent to the plant, (129)I concentrations in aquatic biota were measured by accelerator mass spectrometry. Owing to (129)I discharge from the plant, the (129)I concentration in the biota started to rise from the background concentration in 2006 and was high during 2007-08. The (129)I concentration has been rapidly decreasing after the fuel cutting and chemically processing were finished. The (129)I concentration factors in the biota were higher than those reported by IAEA for marine organisms and similar to those reported for freshwater biota. The estimated annual committed effective dose due to ingestion of foods with the maximum (129)I concentration in the biota samples was 2.8 nSv y(-1). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Explaining the Spatial Variability in Stream Acid Buffering Chemistry and Aquatic Biota in the Neversink River Watershed, Catskill Mountains, New York State

    NASA Astrophysics Data System (ADS)

    Harpold, A. A.; Walter, M. T.

    2009-12-01

    The Neversink River Watershed (NRW) originates at the highest point in the Catskill Mountains and is sensitive to changing patterns in acidic deposition, precipitation, and air temperature. Despite reductions in fossil fuel emission since the Clean Air Act, past acidic deposition has accelerated the leaching of cations from the soil and reduced the stores of base cations necessary for buffering stream acidity. The goal of this study was to investigate connections between different watershed ‘features’ and the apparently complex spatial patterns of stream buffering chemistry (specifically, acid neutralizing capacity ANC and Ca concentrations) and aquatic biota (macroinvertebrate and fish populations). The ten nested NRW watersheds (2.0 km^2 to 176.0 km^2) have relatively homogeneous bedrock geology, forested cover, and soil series; therefore, we hypothesized that differing distributions of hydrological flowpaths between the watersheds control the variability in stream buffering chemistry and aquatic biota. However because the flowpath distributions are not directly measurable, this study used step-wise linear regression to develop relationships between watershed ‘features’ and buffering chemistry. The regression results showed that the mean ratio of precipitation to stream runoff (or runoff ratio) from twenty non-winter storm events explained more than 81% of the variability in mean summer ANC and Ca concentrations. The results also suggested that steeper (higher mean slope) more channelized watersheds (larger drainage density) are more susceptible to stream acidity and negative impacts on biota. A simple linear relationship (using no discharge or water chemistry measurements) was able to explain buffering chemistry and aquatic biota populations in 17 additional NRW watersheds (0.3 km^2 to 160.0 km^2), including 60-80% of the variability in macroinvertebrate populations (EPT richness and BAP) and 50-60% of the variability in fish density and species richness

  11. Upper Clear Creek watershed aquatic chemistry and biota surveys, 2004-5, Whiskeytown National Recreation Area, Shasta County, California

    USGS Publications Warehouse

    Wulff, Marissa L.; May, Jason T.; Brown, Larry R.

    2012-01-01

    The U.S. Geological Survey, in cooperation with the National Park Service and Whiskeytown National Recreation Area, performed a comprehensive aquatic biota survey of the upper Clear Creek watershed, Shasta County, California, during 2004-5. Data collected in this study can provide resource managers with information regarding aquatic resources, watershed degradation, and regional biodiversity within Whiskeytown National Recreation Area. Surveys of water chemistry, bed-sediment chemistry, algae assemblages, benthic macroinvertebrate assemblages, aquatic vertebrate assemblages, in-stream habitat characteristics, and sediment heterogeneity were conducted at 17 stream sites during both 2004 and 2005, with an additional 4 sites surveyed in 2005. A total of 67 bed-sediment samples were analyzed for major and trace inorganic element concentrations. Forty-six water samples were analyzed for trace metals and nutrients. A total of 224 taxa of invertebrates were collected during these surveys. Eleven fish species, seven of which were native, and two species of larval amphibians, were collected. A total of 24 genera of soft algae and 159 taxa of diatoms were identified. To date, this survey represents the most comprehensive inventory of aquatic resources within Whiskeytown National Recreation Area, and this information can serve as a baseline for future monitoring efforts and to inform management decisions.

  12. Effects of flow dynamics on the aquatic-terrestrial transition zone (ATTZ) of lower Missouri river sandbars with implications for selected biota

    USGS Publications Warehouse

    Tracy-Smith, Emily; Galat, David L.; Jacobson, Robert B.

    2012-01-01

    Sandbars are an important aquatic terrestrial transition zone (ATTZ) in the active channel of rivers that provide a variety of habitat conditions for riverine biota. Channelization and flow regulation in many large rivers have diminished sandbar habitats and their rehabilitation is a priority. We developed sandbar-specific models of discharge-area relationships to determine how changes in flow regime affect the area of different habitat types within the submerged sandbar ATTZ (depth) and exposed sandbar ATTZ (elevation) for a representative sample of Lower Missouri River sandbars. We defined six different structural habitat types within the sandbar ATTZ based on depth or exposed elevation ranges that are important to different biota during at least part of their annual cycle for either survival or reproduction. Scenarios included the modelled natural flow regime, current managed flow regime and two environmental flow options, all modelled within the contemporary river active channel. Thirteen point and wing-dike sandbars were evaluated under four different flow scenarios to explore the effects of flow regime on seasonal habitat availability for foraging of migratory shorebirds and wading birds, nesting of softshell turtles and nursery of riverine fishes. Managed flows provided more foraging habitat for shorebirds and wading birds and more nursery habitat for riverine fishes within the channelized reach sandbar ATTZ than the natural flow regime or modelled environmental flows. Reduced summer flows occurring under natural and environmental flow alternatives increased exposed sandbar nesting habitat for softshell turtle hatchling emergence. Results reveal how management of channelized and flow regulated large rivers could benefit from a modelling framework that couples hydrologic and geomorphic characteristics to predict habitat conditions for a variety of biota.

  13. Predicting the vulnerability of streams to episodic acidification and potential effects on aquatic biota in Shenandoah National Park, Virginia

    USGS Publications Warehouse

    Rice, Karen C.; Deviney, Frank A.; Hornberger, George M.; Webb, James R.

    2006-01-01

    Acidic deposition is one of the most serious environmental problems affecting Shenandoah National Park in north-central Virginia. The park is the third most contaminated park in the National Park System because of the deposition of acid rain. Acid rain affects headwater streams in the park by temporarily reducing the acid-neutralizing capacity (ANC) of the water, a process termed episodic acidification. In turn, the increase in acidic components in streamwater can have deleterious effects on the aquatic biota.Although acidic deposition to the park is relatively uniform across its land area, the water-quality response of streamwater during rain events varies substantially. This response is a function of the underlying geology and topographic attributes of watersheds.Geologic and topographic data for the park's 231 watersheds are readily available; however, long-term (years and tens of years) measurements of streamwater ANC and accompanying discharge are not and would be prohibitively expensive to collect. Modeled predictions of the vulnerability of the park's streams to episodic acidification are an alternative to long-term water-quality monitoring. These predictions can aid park officials in making management decisions.

  14. Mercury bioaccumulation in aquatic biota along a salinity gradient in the Saint John River estuary.

    PubMed

    Reinhart, Bethany L; Kidd, Karen A; Curry, R Allen; O'Driscoll, Nelson J; Pavey, Scott A

    2018-06-01

    Although estuaries are critical habitats for many aquatic species, the spatial trends of toxic methylmercury (MeHg) in biota from fresh to marine waters are poorly understood. Our objective was to determine if MeHg concentrations in biota changed along a salinity gradient in an estuary. Fourspine Stickleback (Apeltes quadracus), invertebrates (snails, amphipods, and chironomids), sediments, and water were collected from ten sites along the Saint John River estuary, New Brunswick, Canada in 2015 and 2016, with salinities ranging from 0.06 to 6.96. Total mercury (proxy for MeHg) was measured in whole fish and MeHg was measured in a subset of fish, pooled invertebrates, sediments, and water. Stable sulfur (δ 34 S), carbon (δ 13 C), and nitrogen (δ 15 N) isotope values were measured to assess energy sources (S, C) and relative trophic level (N). There were increases in biotic δ 13 C and δ 34 S from fresh to more saline sites and these measures were correlated with salinity. Though aqueous MeHg was higher at the freshwater than more saline sites, only chironomid MeHg increased significantly with salinity. In the Saint John River estuary, there was little evidence that MeHg and its associated risks increased along a salinity gradient. Copyright © 2018. Published by Elsevier B.V.

  15. GROUP REPORT: PHYSIOLOGICAL AND ECOLOGICAL EFFECTS OF ACIDIFICATION ON AQUATIC BIOTA

    EPA Science Inventory

    Acidification affects all components of biological communities in lakes and streams: microbes, algae, macrophytes, invertebrates, fish, amphibians, and other vertebrates that rely on aquatic ecosystems for habitat or food. echanisms of effect are both direct (toxic responses to c...

  16. Synthesis and interpretation of surface-water quality and aquatic biota data collected in Shenandoah National Park, Virginia, 1979-2009

    USGS Publications Warehouse

    Jastram, John D.; Snyder, Craig D.; Hitt, Nathaniel P.; Rice, Karen C.

    2013-01-01

    Shenandoah National Park in northern and central Virginia protects 777 square kilometers of mountain terrain in the Blue Ridge physiographic province and more than 90 streams containing diverse aquatic biota. Park managers and visitors are interested in the water quality of park streams and its ability to support healthy coldwater communities and species, such as the native brook trout (Salvelinus fontinalis), that are at risk in the eastern United States. Despite protection from local stressors, however, the water quality of streams in the park is at risk from many regional stressors, including atmospheric pollution, decline in the health of the surrounding forests because of invasive forest pests, and global climate change. In 2010, the U.S. Geological Survey, in cooperation with the National Park Service, undertook a study to compile, analyze, and synthesize available data on water quality, aquatic macroinvertebrates, and fish within Shenandoah National Park. Specifically, the effort focused on creating a comprehensive water-resources database for the park that can be used to evaluate temporal trends and spatial patterns in the available data, and characterizing those data to better understand interrelations among water quality, aquatic macroinvertebrates, fish, and the landscape.

  17. A conceptual framework for assessing impacts of roads on aquatic biota

    Treesearch

    Paul L. Angermeier; Andrew P. Wheeler; Amanda E. Rosenberger

    2004-01-01

    Roads are pervasive in modern landscapes and adversely affect many aquatic ecosystems. Conventional environmental assessments of roads focus on construction impacts but ignore subsequent impacts. A comprehensive framework for considering all impacts of roads would enable scientists and managers to develop assessment tools that more accurately inform stakeholders and...

  18. Spring-fen habitat islands in a warming climate: Partitioning the effects of mesoclimate air and water temperature on aquatic and terrestrial biota.

    PubMed

    Horsák, Michal; Polášková, Vendula; Zhai, Marie; Bojková, Jindřiška; Syrovátka, Vít; Šorfová, Vanda; Schenková, Jana; Polášek, Marek; Peterka, Tomáš; Hájek, Michal

    2018-09-01

    Climate warming and associated environmental changes lead to compositional shifts and local extinctions in various ecosystems. Species closely associated with rare island-like habitats such as groundwater-dependent spring fens can be severely threatened by these changes due to a limited possibility to disperse. It is, however, largely unknown to what extent mesoclimate affects species composition in spring fens, where microclimate is buffered by groundwater supply. We assembled an original landscape-scale dataset on species composition of the most waterlogged parts of isolated temperate spring fens in the Western Carpathian Mountains along with continuously measured water temperature and hydrological, hydrochemical, and climatic conditions. We explored a set of hypotheses about the effects of mesoclimate air and local spring-water temperature on compositional variation of aquatic (macroinvertebrates), semi-terrestrial (plants) and terrestrial (land snails) components of spring-fen biota, categorized as habitat specialists and other species (i.e. matrix-derived). Water temperature did not show a high level of correlation with mesoclimate. For all components, fractions of compositional variation constrained to temperature were statistically significant and higher for habitat specialists than for other species. The importance of air temperature at the expense of water temperature and its fluctuation clearly increased with terrestriality, i.e. from aquatic macroinvertebrates via vegetation (bryophytes and vascular plants) to land snails, with January air temperature being the most important factor for land snails and plant specialists. Some calcareous-fen specialists with a clear distribution centre in temperate Europe showed a strong affinity to climatically cold sites in our study area and may hence be considered as threatened by climate warming. We conclude that prediction models solely based on air temperature may provide biased estimates of future changes in

  19. Effects of acidification on metal availability to aquatic biota, with special reference to filamentous algae.

    PubMed

    Stokes, P M; Bailey, R C; Groulx, G R

    1985-11-01

    A survey of 34 shield lakes in Ontario and Quebec, pH 4.4 to 7.1, was made to evaluate which metals should be considered of concern as a risk to aquatic biota or consumers when lakes are acid stressed. A set of predictions, concerning the mobilization by man, the mobility, the chemical speciation, and the toxicity or bioaccumulation of metals in acid-stressed waters, were used as a basis for designing the study and organizing the results. Attached algae were used as biomonitors to assess metal bioavailability. The study concluded that zinc, lead, aluminum, and mercury were of concern in acid-stressed lakes, while the situation for manganese was unresolved, and cadmium was not studied. Nickel and copper were of concern only when a point source was involved. The study also concluded that the attached algal community had some value as a biomonitor, for metals in acid-stressed as well as metal-polluted surface waters.

  20. Effects of acidification on metal availability to aquatic biota, with special reference to filamentous algae.

    PubMed Central

    Stokes, P M; Bailey, R C; Groulx, G R

    1985-01-01

    A survey of 34 shield lakes in Ontario and Quebec, pH 4.4 to 7.1, was made to evaluate which metals should be considered of concern as a risk to aquatic biota or consumers when lakes are acid stressed. A set of predictions, concerning the mobilization by man, the mobility, the chemical speciation, and the toxicity or bioaccumulation of metals in acid-stressed waters, were used as a basis for designing the study and organizing the results. Attached algae were used as biomonitors to assess metal bioavailability. The study concluded that zinc, lead, aluminum, and mercury were of concern in acid-stressed lakes, while the situation for manganese was unresolved, and cadmium was not studied. Nickel and copper were of concern only when a point source was involved. The study also concluded that the attached algal community had some value as a biomonitor, for metals in acid-stressed as well as metal-polluted surface waters. PMID:4076097

  1. Modeled and monitored variation in space and time of PCB-153 concentrations in air, sediment, soil and aquatic biota on a European scale.

    PubMed

    Hauck, Mara; Huijbregts, Mark A J; Hollander, Anne; Hendriks, A Jan; van de Meent, Dik

    2010-08-15

    We evaluated various modeling options for estimating concentrations of PCB-153 in the environment and in biota across Europe, using a nested multimedia fate model coupled with a bioaccumulation model. The most detailed model set up estimates concentrations in air, soil, fresh water sediment and fresh water biota with spatially explicit environmental characteristics and spatially explicit emissions to air and water in the period 1930-2005. Model performance was evaluated with the root mean square error (RMSE(log)), based on the difference between estimated and measured concentrations. The RMSE(log) was 5.4 for air, 5.6-6.3 for sediment and biota, and 5.5 for soil in the most detailed model scenario. Generally, model estimations tended to underestimate observed values for all compartments, except air. The decline in observed concentrations was also slightly underestimated by the model for the period where measurements were available (1989-2002). Applying a generic model setup with averaged emissions and averaged environmental characteristics, the RMSE(log) increased to 21 for air and 49 for sediment. For soil the RMSE(log) decreased to 3.5. We found that including spatial variation in emissions was most relevant for all compartments, except soil, while including spatial variation in environmental characteristics was less influential. For improving predictions of concentrations in sediment and aquatic biota, including emissions to water was found to be relevant as well. Copyright 2009 Elsevier B.V. All rights reserved.

  2. Surface-water-quality assessment of the Yakima River basin in Washington; spatial and temporal distribution of trace elements in water, sediment, and aquatic biota, 1987-91; with a section on geology

    USGS Publications Warehouse

    Fuhrer, Gregory J.; Cain, Daniel J.; McKenzie, Stuart W.; Rinella, Joseph F.; Crawford, J. Kent; Skach, Kenneth A.; Hornberger, Michelle I.; Gannett, Marshall W.

    1999-01-01

    The report describes the distribution of trace elements in sediment, water, and aquatic biota in the Yakima River basin, Washington. Trace elements were determined from streambed sediment, suspended sediment, filtered and unfiltered water samples, aquatic insects, clams, fish livers, and fish fillets between 1987 and 1991. The distribution of trace elements in these media was related to local geology and anthropogenic sources. Additionally, annual and instantaneous loads were estimated for trace elements associated with suspended sediment and trace elements in filtered water samples. Trace elements also were screened against U.S. Environmental Protection Agency guidelines established for the protection of human health and aquatic life.

  3. Ethoprophos fate on soil-water interface and effects on non-target terrestrial and aquatic biota under Mediterranean crop-based scenarios.

    PubMed

    Leitão, Sara; Moreira-Santos, Matilde; Van den Brink, Paul J; Ribeiro, Rui; José Cerejeira, M; Sousa, José Paulo

    2014-05-01

    The present study aimed to assess the environmental fate of the insecticide and nematicide ethoprophos in the soil-water interface following the pesticide application in simulated maize and potato crops under Mediterranean agricultural conditions, particularly of irrigation. Focus was given to the soil-water transfer pathways (leaching and runoff), to the pesticide transport in soil between pesticide application (crop row) and non-application areas (between crop rows), as well as to toxic effects of the various matrices on terrestrial and aquatic biota. A semi-field methodology mimicking a "worst-case" ethoprophos application (twice the recommended dosage for maize and potato crops: 100% concentration v/v) in agricultural field situations was used, in order to mimic a possible misuse by the farmer under realistic conditions. A rainfall was simulated under a slope of 20° for both crop-based scenarios. Soil and water samples were collected for the analysis of pesticide residues. Ecotoxicity of soil and aquatic samples was assessed by performing lethal and sublethal bioassays with organisms from different trophic levels: the collembolan Folsomia candida, the earthworm Eisenia andrei and the cladoceran Daphnia magna. Although the majority of ethoprophos sorbed to the soil application area, pesticide concentrations were detected in all water matrices illustrating pesticide transfer pathways of water contamination between environmental compartments. Leaching to groundwater proved to be an important transfer pathway of ethoprophos under both crop-based scenarios, as it resulted in high pesticide concentration in leachates from Maize (130µgL(-1)) and Potato (630µgL(-1)) crop scenarios, respectively. Ethoprophos application at the Potato crop scenario caused more toxic effects on terrestrial and aquatic biota than at the Maize scenario at the recommended dosage and lower concentrations. In both crop-based scenarios, ethoprophos moved with the irrigation water flow to the

  4. Predicting toxic effects of copper on aquatic biota in mineralized areas by using the Biotic Ligand Model

    USGS Publications Warehouse

    Smith, Kathleen S.; Ranville, James F.; Adams, M.; Choate, LaDonna M.; Church, Stan E.; Fey, David L.; Wanty, Richard B.; Crock, James G.

    2006-01-01

    The chemical speciation of metals influences their biological effects. The Biotic Ligand Model (BLM) is a computational approach to predict chemical speciation and acute toxicological effects of metals on aquatic biota. Recently, the U.S. Environmental Protection Agency incorporated the BLM into their regulatory water-quality criteria for copper. Results from three different laboratory copper toxicity tests were compared with BLM predictions for simulated test-waters. This was done to evaluate the ability of the BLM to accurately predict the effects of hardness and concentrations of dissolved organic carbon (DOC) and iron on aquatic toxicity. In addition, we evaluated whether the BLM and the three toxicity tests provide consistent results. Comparison of BLM predictions with two types of Ceriodaphnia dubia toxicity tests shows that there is fairly good agreement between predicted LC50 values computed by the BLM and LC50 values determined from the two toxicity tests. Specifically, the effect of increasing calcium concentration (and hardness) on copper toxicity appears to be minimal. Also, there is fairly good agreement between the BLM and the two toxicity tests for test solutions containing elevated DOC, for which the LC50 is 3-to-5 times greater (less toxic) than the LC50 for the lower-DOC test water. This illustrates the protective effects of DOC on copper toxicity and demonstrates the ability of the BLM to predict these protective effects. In contrast, for test solutions with added iron there is a decrease in LC50 values (increase in toxicity) in results from the two C. dubia toxicity tests, and the agreement between BLM LC50 predictions and results from these toxicity tests is poor. The inability of the BLM to account for competitive iron binding to DOC or DOC fractionation may be a significant shortcoming of the BLM for predicting site- specific water-quality criteria in streams affected by iron-rich acidic drainage in mined and mineralized areas.

  5. DEVELOPMENT OF A DISTURBANCE INDEX TO ASSESS THE CONDITION OF AQUATIC ECOSYSTEMS

    EPA Science Inventory

    An objective of aquatic monitoring is to assess the condition of aquatic habitats and biota. To rationally interpret aquatic condition, we must identify the range of human activities and the risks they pose to aquatic ecosystems. Placing stream reaches and their watersheds on a...

  6. Microplastics in aquatic environments: Implications for Canadian ecosystems.

    PubMed

    Anderson, Julie C; Park, Bradley J; Palace, Vince P

    2016-11-01

    Microplastics have been increasingly detected and quantified in marine and freshwater environments, and there are growing concerns about potential effects in biota. A literature review was conducted to summarize the current state of knowledge of microplastics in Canadian aquatic environments; specifically, the sources, environmental fate, behaviour, abundance, and toxicological effects in aquatic organisms. While we found that research and publications on these topics have increased dramatically since 2010, relatively few studies have assessed the presence, fate, and effects of microplastics in Canadian water bodies. We suggest that efforts to determine aquatic receptors at greatest risk of detrimental effects due to microplastic exposure, and their associated contaminants, are particularly warranted. There is also a need to address the gaps identified, with a particular focus on the species and conditions found in Canadian aquatic systems. These gaps include characterization of the presence of microplastics in Canadian freshwater ecosystems, identifying key sources of microplastics to these systems, and evaluating the presence of microplastics in Arctic waters and biota. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  7. Rivers and streams: Physical setting and adapted biota

    USGS Publications Warehouse

    Wilzbach, Margaret A.; Cummins, K.W.

    2008-01-01

    Streams and rivers are enormously important, with their ecological, and economic value, greatly outweighing their significance on the landscape. Lotic ecology began in Europe with a focus on the distribution, abundance, and taxonomic composition of aquatic organisms and in North American with a focus on fishery biology. Since 1980, stream/river research has been highly interdisciplinary, involving fishery biologists, aquatic entomologists, algologists, hydrologists, geomorphologists, microbiologists, and terrestrial plant ecologists. Stream and river biota evolved in response to, and in concert with, the physical and chemical setting. Streams/rivers transport water and move sediments to the sea as part of the hydrologic cycle that involves evaporation, plant evapotranspiration, and precipitation. Ephemeral streams flow only in the wettest year, intermittent streams flow predictably every year during capture of surface runoff, and perennial streams flow continuously during wet and dry periods, receiving both stormflow and groundwater baseflow. The lotic biota, for example, algae, macrophytes, benthic invertebrates, and fishes, have evolved adaptations to their running-water setting. Dominant physical features of this setting are current, substrate, and temperature. Key chemical constituents are dissolved gases, dissolved inorganic ions and compounds, particulate inorganic material, particulate organic material, and dissolved organic ions (nitrogen and phosphorus) and compounds.

  8. ENANTIOMERIC COMPOSITION OF CHIRAL POLYCHLORINATED BIPHENYL ATROPISOMERS IN AQUATIC AND RIPARIAN BIOTA

    EPA Science Inventory

    The enantiomeric composition of polychlorinated biphenyl (PCB) atropisomers was measured in river and riparian biota (fish, bivalves, crayfish, water snakes, barn swallows) from selected sites throughout the United States by using chiral gas chromatography/mass spectrometry. Nonr...

  9. Temporal monitoring of perfluorooctane sulfonate accumulation in aquatic biota downstream of historical aqueous film forming foam use areas.

    PubMed

    Lanza, Heather A; Cochran, Rebecca S; Mudge, Joseph F; Olson, Adric D; Blackwell, Brett R; Maul, Jonathan D; Salice, Christopher J; Anderson, Todd A

    2017-08-01

    Perfluoroalkyl substances (PFAS) have recently received increased research attention, particularly concerning aquatic organisms and in regions of exposure to aqueous film forming foams (AFFFs). Air Force bases historically applied AFFFs in the interest of fire training exercises and have since expressed concern for PFAS contamination in biota from water bodies surrounding former fire training areas. Six PFAS were monitored, including perfluorooctane sulfonate (PFOS), in aquatic species from 8 bayou locations at Barksdale Air Force Base in Bossier City, Louisiana (USA) over the course of 1 yr. The focus was to evaluate temporal and spatial variability in PFAS concentrations from historic use of AFFF. The PFOS concentrations in fish peaked in early summer, and also increased significantly downstream of former fire training areas. Benthic organisms had lower PFOS concentrations than pelagic species, contrary to previous literature observations. Bioconcentration factors varied with time but were reduced compared with previously reported literature values. The highest concentration of PFOS in whole fish was 9349 ng/g dry weight, with 15% of samples exceeding what is believed to be the maximum whole fish concentration reported to date of 1500 ng/g wet weight. Further studies are ongoing, to measure PFAS in larger fish and tissue-specific partitioning data to compare with the current whole fish values. The high concentrations presently observed could have effects on higher trophic level organisms in this system or pose a potential risk to humans consuming contaminated fish. Environ Toxicol Chem 2017;36:2022-2029. © 2016 SETAC. © 2016 SETAC.

  10. Assessing the attributable risks, relative risks, and regional extents of aquatic stressors

    EPA Science Inventory

    A major goal of the national aquatic surveys being conducted by the Environmental Protection Agency in partnership with the states and tribes is to assess the relative importance, at a regional scale, of stressors that impact aquatic biota. The Wadeable Streams Assessment (WSA) w...

  11. Assessing the suitability of stream water for five different uses and its aquatic environment.

    PubMed

    Fulazzaky, Mohamad Ali

    2013-01-01

    Surface water is one of the essential resources for supporting sustainable development. The suitability of such water for a given use depends both on the available quantity and tolerable quality. Temporary status for a surface water quality has been identified extensively. Still the suitability of the water for different purposes needs to be verified. This study proposes a water quality evaluation system to assess the aptitude of the Selangor River water for aquatic biota, drinking water production, leisure and aquatic sport, irrigation use, livestock watering, and aquaculture use. Aptitude of the water has been classified in many parts of the river segment as unsuitable for aquatic biota, drinking water production, leisure and aquatic sport as well as aquaculture use. The water quality aptitude classes of the stream water for nine locations along the river are evaluated to contribute to decision support system. The suitability of the water for five different uses and its aquatic ecosystem are verified.

  12. Baseline assessment of physical characteristics, aquatic biota, and selected water-quality properties at the reach and mesohabitat scale for three stream reaches in the Big Cypress Basin, northeastern Texas, 2010-11

    USGS Publications Warehouse

    Braun, Christopher L.; Moring, James B.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Northeast Texas Municipal Water District and the Texas Commission on Environmental Quality, did a baseline assessment in 2010-11 of physical characteristics and selected aquatic biota (fish and mussels) collected at the mesohabitat scale for three stream reaches in the Big Cypress Basin in northeastern Texas for which environmental flows have been prescribed. Mesohabitats are visually distinct units of habitat within the stream with unique depth, velocity, slope, substrate, and cover. Mesohabitats in reaches of Big Cypress, Black Cypress, and Little Cypress Bayous were evaluated to gain an understanding of how fish communities and mussel populations varied by habitat. Selected water-quality properties were also measured in isolated pools in Black Cypress and Little Cypress. All of the data were collected in the context of the prescribed environmental flows. The information acquired during the study will support the long-term monitoring of biota in relation to the prescribed environmental flows.

  13. Surface-water-quality assessment of the Yakima River basin, Washington; distribution of pesticides and other organic compounds in water, sediment, and aquatic biota, 1987-91; with a section on dissolved organic carbon in the Yakima River basin

    USGS Publications Warehouse

    Rinella, Joseph F.; McKenzie, Stuart W.; Crawford, J. Kent; Foreman, William T.; Fuhrer, Gregory J.; Morace, Jennifer L.; Aiken, George R.

    1999-01-01

    During 1987-91, chemical data were collected for pesticides and other organic compounds in surface water, streambed sediment, suspended sediment, agricultural soil, and aquatic biota to determine the occurrence, distribution, transport, and fate of organic compounds in the Yakima River basin in Washington. The report describes the chemical and physical properties of the compounds most frequently detected in the water column; organochlorine compounds including DDT, organophosphorus compounds, thiocarbamate and sulfite compounds, acetamide and triazine compounds, and chlorophenoxy-acetic acid and benzoic compounds. Concentrations are evaluated relative to chronic-toxicity water quality criteria and guidelines for the protection of human health and freshwater aquatic life.

  14. Carbon-14 Specific Activity Model Validation for Biota in Wetland Environments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yankovich, T.L.; Sharp, K.J.; Benz, M.L.

    2008-01-15

    {sup 14}C in resident Duke Swamp biota were compared to levels measured in environmental media (including moss, soil and air) to determine whether concentrations in such media reflect animal exposure, for application in routine environmental monitoring programs on the CRL site. In general, for most types of receptor animals, {sup 14}C specific activities were found to be similar to or less than those measured in air, soil and surface vegetation at all locations sampled, suggesting that in most cases, estimates of {sup 14}C levels in animals could either be realistically or conservatively predicted based on the values measured in environmental media. In the case of fungi, receptor-to-media {sup 14}C specific activity ratios fell between 0.04 and 0.23 relative to air, between 0.03 and 0.70 relative to soil, and between 0.078 and 0.31 relative to moss. Small mammal specific activities also generally fell well below those that would be predicted based on specific activities measured in environmental media, with ratios ranging from 0.11 to 0.36 relative to air, from 0.17 to 0.85 relative to soil and from 0.21 to 0.58 relative to moss. Similar ratios were also established for snakes; however, a notable exception occurred for amphibians, a type of animal that tends to spend relatively more time in aquatic environments than the other species tested. In the case of Duke Swamp amphibians, animal-to-air {sup 14}C specific activity ratios ranged from 0.40 to 2.3, animal-to-soil ratios ranged from 0.81 to 3.4 and animal-to-moss ratios ranged from 1.5 to 2.4. These higher {sup 14}C levels in amphibians relative to the environmental media may be due to increased {sup 14}C exposure of aquatic or amphibious animals that occupy systems receiving inputs via groundwater. In such systems, {sup 14}C is incorporated in aquatic plants and animals, and later transferred to higher predatory species, such as amphibians, that consume them. Therefore, with the exception of amphibians and other

  15. Changes in Benthic Biota between Mountain and Urban Streams

    NASA Astrophysics Data System (ADS)

    Sato, H.; Iijima, A.

    2016-12-01

    It is well known that the benthic biota in the river ecosystem changes drastically between the mountain and urban streams. However, there are few studies demonstrating the changes in biota by using quantitative techniques. In this study, field research on benthic species (mainly aquatic insects) was carried out at 6 different sites in the Kanna River in Japan. After that, we compared the biota quantitatively by using an EPT (Ephemeroptera, Plecoptera, and Trichoptera) index and a pollution index (Pantle-Buck Method). Moreover, we applied a cluster analysis to determine the statistical difference in the benthic biota among the sites. The monitoring stations (St.1-St.6 in order from the upper stream) were placed in the reaches of the Kanna River that is one of the headstreams flowing into the Tone River (fig.1-a). In those monitoring stations, St.1-3 are located in the mountain area, and St.4-6 are in the urban area. Field research was carried out every other month during February 2012 to January 2013 by a Beck-Tsuda β method. In total, we identified 7879 benthos of 153 species (fig.1-b). The EPT index tended to decrease toward the lower reaches (fig.1-c). Moreover, there were significant changes in the composition of EPT species between the mountain (St.1-3) and urban (St.4-6) area. In particular, Plecoptera species which has no pollution tolerance decreased drastically in the urban stream. The values of pollution index tended to increase toward the lower reaches (fig.1-d). In fact, the lower reaches of the Kanna River has a large population who has insufficient sewage treatment system. This is consistent with the changes in the EPT species. Cluster analysis demonstrated that the benthic biota in the Kanna River has been divided between St.3 and 4. Consequently, the water contamination in the urban stream is supposed to be the main cause of significant changes in benthic biota in the Kanna River's ecosystem.

  16. Chesapeake Bay Low Freshwater Inflow Study. Biota Assessment. Phase I. Volume I.

    DTIC Science & Technology

    1980-08-01

    Percentage as Larvae Containing Food Item . . . 70 111-9. Submerged Aquatic Vegetation Found in Maryland and Virginia Waters of the Chesapeake Bay ... .... 74...Composition or the 1977 and 1978 Water - fowl Hunting Kill for Maryland and Virginia. . . . 117 IV-1. Annual Mean Freshwater Inflow to Chesapeake Bay...15C IV-3. Sumary of Water Quality Factors Impacting the Low Freshwater Inflow on Biota .. ............. 163 IV-4. Ranked Relative Importance of

  17. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in and near Stillwater Wildlife Management Area, Churchill County, Nevada, 1986-87

    USGS Publications Warehouse

    Hoffman, R.J.; Hallock, R.J.; Rowe, T.G.; Lico, M.S.; Burge, H.L.; Thompson, S.P.

    1990-01-01

    A reconnaissance was initiated in 1986 to determine whether the quality of irrigation-drainage water in and near the Stillwater Wildlife Management Area, Nevada, has caused or has potential to cause harmful effects on human health, fish, wildlife, or other beneficial uses of water. Samples of surface and groundwater, bottom sediment, and biota were collected from sites upstream and downstream from the Fallon agricultural area in the Carson Desert, and analyzed for potentially toxic trace elements. Other analysis included radioactive substances, major dissolved constituents, and nutrients in water, and pesticide residues in bottom sediment and biota. In areas affected by irrigation drainage, the following constituents were found to commonly exceed baseline concentrations or recommended criteria for protection of aquatic life or propagation of wildlife: In water, arsenic, boron, dissolved solids, molybdenum, sodium, and un-ionized ammonia; in bottom sediments, arsenic, lithium, mercury, molybdenum, and selenium; and in biota, arsenic, boron, chromium, copper, mercury, selenium, and zinc. In some wetlands, selenium and mercury appeared to be biomagnified, and arsenic bioaccumulated. Pesticides contamination in bottom sediments and biota was insignificant. Adverse biological effects observed during this reconnaissance included gradual vegetative changes and species loss, fish die-offs, waterfowl disease epidemics, and persistent and unexplained deaths of migratory birds. (USGS)

  18. Environmental Setting and the Effects of Natural and Human-Related Factors on Water Quality and Aquatic Biota, Oahu, Hawaii

    USGS Publications Warehouse

    Oki, Delwyn S.; Brasher, Anne M.D.

    2003-01-01

    -use patterns on Oahu reflected increases in population and decreases in large-scale agricultural operations over time. The last two remaining sugarcane plantations on Oahu closed in the mid-1990's, and much of the land that once was used for sugarcane now is urbanized or used for diversified agriculture. Although two large pineapple plantations continue to operate in central Oahu, some of the land previously used for pineapple cultivation has been urbanized. Natural and human-related factors control surface- and ground-water quality and the distribution and abundance of aquatic biota on Oahu. Natural factors that may affect water quality include geology, soils, vegetation, rainfall, ocean-water quality, and air quality. Human-related factors associated with urban and agricultural land uses also may affect water quality. Ground-water withdrawals may cause saltwater intrusion. Pesticides and fertilizers that were used in agricultural or urban areas have been detected in surface and ground water on Oahu. In addition, other organic compounds associated with urban uses of chemicals have been detected in surface and ground water on Oahu. The effects of urbanization and agricultural practices on instream and riparian areas in conjunction with a proliferation of nonnative fish and crustaceans have resulted in a paucity of native freshwater macrofauna on Oahu. A variety of pesticides, nutrients, and metals are associated with urban and agricultural land uses, and these constituents can affect the fish and invertebrates that live in the streams.

  19. Concordant Biogeographic Patterns among Multiple Taxonomic Groups in the Mexican Freshwater Biota

    PubMed Central

    Quiroz-Martínez, Benjamín; Álvarez, Fernando; Espinosa, Héctor; Salgado-Maldonado, Guillermo

    2014-01-01

    In this paper we analyse the degree of concordance in species richness and taxonomic distinctness (diversity) patterns among different freshwater taxonomic groups in order to test three long held patterns described in Mexican freshwater biogeography: 1. The aquatic biota of Mexico includes two distinct faunas, a rich Neotropical component in the south and a south-eastern region and a less rich Nearctic component towards central and northern latitudes of the country. 2. A hotspot of species richness and diversity has been recorded in the Usumacinta, including the Yucatan Peninsula. 3. The presence of two distinct biotas in Mexico, an eastern one distributed along the Gulf of Mexico slope, and a western one associated to the Pacific versant. We use species richness and taxonomic distinctness to explore patterns of diversity and how these patterns change between zoogeographical regions. This paper points out a clear separation between Neotropical and Nearctic drainage basins but also between eastern (Gulf of Mexico) and western (Pacific) drainage basins. Present data gives additional empirical support from freshwater biota for three long held beliefs regarding distributional patterns of the Mexican biota. The neotropical basins of Mexico are generally host to a richest and more diversified fauna, that includes more families, genera and species, compared to the less rich and less diverse fauna in the nearctic basins. PMID:25136979

  20. Pu-239 organ specific dosimetric model applied to non-human biota

    NASA Astrophysics Data System (ADS)

    Kaspar, Matthew Jason

    There are few locations throughout the world, like the Maralinga nuclear test site located in south western Australia, where sufficient plutonium contaminate concentration levels exist that they can be utilized for studies of the long-term radionuclide accumulation in non-human biota. The information obtained will be useful for the potential human users of the site while also keeping with international efforts to better understand doses to non-human biota. In particular, this study focuses primarily on a rabbit sample set collected from the population located within the site. Our approach is intended to employ the same dose and dose rate methods selected by the International Commission on Radiological Protection and adapted by the scientific community for similar research questions. These models rely on a series of simplifying assumptions on biota and their geometry; in particular; organisms are treated as spherical and ellipsoidal representations displaying the animal mass and volume. These simplifications assume homogeneity of all animal tissues. In collaborative efforts between Colorado State University and the Australian Nuclear Science and Technology Organisation (ANSTO), we are expanding current knowledge on radionuclide accumulation in specific organs causing organ-specific dose rates, such as Pu-239 accumulating in bone, liver, and lungs. Organ-specific dose models have been developed for humans; however, little has been developed for the dose assessment to biota, in particular rabbits. This study will determine if it is scientifically valid to use standard software, in particular ERICA Tool, as a means to determine organ-specific dosimetry due to Pu-239 accumulation in organs. ERICA Tool is normally applied to whole organisms as a means to determine radiological risk to whole ecosystems. We will focus on the aquatic model within ERICA Tool, as animal organs, like aquatic organisms, can be assumed to lie within an infinite uniform medium. This model would

  1. Applying DOE's Graded Approach for assessing radiation impacts to non-human biota at the INL.

    PubMed

    Morris, Randall C

    2006-01-01

    In July 2002, The US Department of Energy (DOE) released a new technical standard entitled A Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota. DOE facilities are annually required to demonstrate that routine radioactive releases from their sites are protective of non-human receptors and sites are encouraged to use the Graded Approach for this purpose. Use of the Graded Approach requires completion of several preliminary steps, to evaluate the degree to which the site environmental monitoring program is appropriate for evaluating impacts to non-human biota. We completed these necessary activities at the Idaho National Laboratory (INL) using the following four tasks: (1) develop conceptual models and evaluate exposure pathways; (2) define INL evaluation areas; (3) evaluate sampling locations and media; (4) evaluate data gaps. All of the information developed in the four steps was incorporated, data sources were identified, departures from the Graded Approach were justified, and a step-by-step procedure for biota dose assessment at the INL was specified. Finally, we completed a site-wide biota dose assessment using the 2002 environmental surveillance data and an offsite assessment using soil and surface water data collected since 1996. These assessments demonstrated the environmental concentrations of radionuclides measured on and near the INL do not present significant risks to populations of non-human biota.

  2. Toxicological impact of cadmium-based quantum dots towards aquatic biota: Effect of natural sunlight exposure.

    PubMed

    Silva, B F; Andreani, T; Gavina, A; Vieira, M N; Pereira, C M; Rocha-Santos, T; Pereira, R

    2016-07-01

    Cadmium-based quantum dots (QDs) are increasingly applied in existent and emerging technologies, especially in biological applications due to their exceptional photophysical and functionalization properties. However, they are very toxic compounds due to the high reactive and toxic cadmium core. The present study aimed to determine the toxicity of three different QDs (CdS 380, CdS 480 and CdSeS/ZnS) before and after the exposure of suspensions to sunlight, in order to assess the effect of environmentally relevant irradiation levels in their toxicity, which will act after their release to the environment. Therefore, a battery of ecotoxicological tests was performed with organisms that cover different functional and trophic levels, such as Vibrio fischeri, Raphidocelis subcapitata, Chlorella vulgaris and Daphnia magna. The results showed that core-shell type QDs showed lower toxic effects to V. fischeri in comparison to core type QDs before sunlight exposure. However, after sunlight exposure, there was a decrease of CdS 380 and CdS 480 QD toxicity to bacterium. Also, after sunlight exposure, an effective decrease of CdSeS/ZnS and CdS 480 toxicity for D. magna and R. subcapitata, and an evident increase in CdS 380 QD toxicity, at least for D. magna, were observed. The results of this study suggest that sunlight exposure has an effect in the aggregation and precipitation reactions of larger QDs, causing the degradation of functional groups and formation of larger bulks which may be less prone to photo-oxidation due to their diminished surface area. The same aggregation behaviour after sunlight exposure was observed for bare QDs. These results further emphasize that the shell of QDs seems to make them less harmful to aquatic biota, both under standard environmental conditions and after the exposure to a relevant abiotic factor like sunlight. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Residues, bioaccumulations and biomagnification of perfluoroalkyl acids (PFAAs) in aquatic animals from Lake Chaohu, China.

    PubMed

    Liu, Wenxiu; He, Wei; Wu, Jingyi; Qin, Ning; He, Qishuang; Xu, Fuliu

    2018-05-12

    Residual levels of perfluoroalkyl acids (PFAAs) in seven species of aquatic animals were analyzed by liquid chromatography-mass spectrometry. The distribution, composition, bioaccumulation, and biomagnification of PFAAs and their effect factors were studied. The results showed that: 1) Wet weight concentrations of 17 PFAAs in the aquatic animals ranged from 1.77 to 38.65 ng/g, with a mean value of 12.71 ± 9.21 ng/g. PFOS was the predominant contaminant (4.57 ± 4.57 ng/g, 6.76%-46.25%), followed by PFDA (1.95 ± 1.37 ng/g, 11.68%-21.25%) and PFUdA (1.84 ± 1.21 ng/g, 9.73%-35.34%. 2) PFAA residual levels in Culter erythropterus (30.98 ± 6.65 ng/g) were the highest, followed by Hemibarbus maculatus (16.79 ± 1.88 ng/g), while the PFAA levels in Carassius auratus were the lowest (2.22 ± 0.60 ng/g). 3) Biota-water bioaccumulation factors (BAFs), biota-suspended solid accumulation factors (BSSAFs) and biota-sediment accumulation factors (BSAFs) ranged from 0.35 to 12,370.51, 7.77 to 8452.92 and 9.10 to 6984.61, respectively. Bioaccumulation by shrimp and snails was significantly affected by Kow. 4) Food web magnification factors were greater than 1, indicating that biomagnification of PFAAs occurs across trophic levels. The bioaccumulation and biomagnification of PFAAs were significantly correlated with carbon chain length. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. E-waste disposal effects on the aquatic environment: Accra, Ghana.

    PubMed

    Huang, Jingyu; Nkrumah, Philip Nti; Anim, Desmond Ofosu; Mensah, Ebenezer

    2014-01-01

    , the need for actions to be taken to reduce entry of e-waste pollutants into Ghana's aquatic environment is real and is immediate.Heavy metals (e.g., lead, cadmium, copper and zinc) and organic pollutants (e.g.,PCDD/Fs and PBDEs) have been detected in the sediments of local water bodies in quantities that greatly exceed background levels. This fact alone suggests that aquatic organisms that live in the affected water bodies are highly exposed to these toxic, bio-accumulative, and persistent contaminants. These contaminants have been confirmed to result from the primitive methods used to recycle and process e-waste within the local environment.Only limited local data exist on the threats posed by these e-waste-related contaminants on nearby natural resources, especially aquatic organisms. In this review,we have addressed the potential toxicity of selected heavy metals and organic pollutants on aquatic organisms. Since there are no data on concentrations of contaminants in the water column, we have based our predictions of effects on pollutant release rates from sediments. Pollutants that are attached to sediments are routinely released into the water column from diffusion and advection, the rate of which depends on pH and Eh of the sediments. E-waste contaminants have the potential to produce deleterious effects on the behavior, physiology, metabolism, reproduction,development and growth of many aquatic organisms. Because it is confirmed that both heavy metal and organic contaminants are reaching the biota of Ghana's local waterways, we presume that they are producing adverse effects. Because local data on the aquatic toxicity of these contaminants are as yet unavailable, we strongly recommend that future research be undertaken to examine, on a large scale and long-term basis, both contamination levels in biota, and adverse effects on biota of the nearby water bodies.

  5. Summary of information on aquatic biota and their habitats in the Willamette Basin, Oregon, through 1995

    USGS Publications Warehouse

    Altman, Bob; Henson, C.M.; Waite, I.R.

    1997-01-01

    Aquatic toxicological investigations in the basin have focused primarily on fish. These studies have addressed chlorinated pesticides, polychlorinated biphenyls (PCBs), dioxins and furans, polycyclic aromatic hydrocarbons (PAHs), and trace elements in aquatic tissue, as well as fish health assessments, skeletal abnormalities, and aquatic toxicological responses. Several pesticides exceeded U.S. Environmental Protection Agency and State water-quality criteria for the protection of aquatic life. Elevated PCB, dioxin, and furan concentrations were associated with point sources, such as pulp and paper mills. Elevated concentrations of mercury in aquatic tissue were associated with several reservoirs. Fish health assessments and skeletal abnormality studies detected high levels of abnormalities in fish from the main stem Willamette River. Few investigations have examined aquatic toxicological responses, such as enzyme induction assays, growth assays, and biomarker studies.

  6. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Columbia Basin Project, Washington, 1991-92

    USGS Publications Warehouse

    Embrey, S.S.; Block, E.K.

    1995-01-01

    The reconnaissance investigation results indicated that irrigation drainage generally has not adversely affected biota in the Columbia Basin Project. Hazards to biota from large concentrations of certain trace elements in water and bottom sediment, and caused by high evaporation rates in irrigated arid lands, are reduced by imported, dilute Columbia River water. However, boron concentrations in aquatic plants might affect waterfowl feeding on these plants and arsenic concentrations in juvenile coots were similar to those in mallard ducklings who exhibited abnormalities after being fed an arsenic-supplemented diet. During irrigation season, concentrations of boron, nitrate, and dissolved solids in water were increased in the southern wasteways because of water reuse. During non-irrigation season, constituent concentrations were large when stream flows are sustained by return water from tile drains and ground water. However, concentrations of dissolved constituents typically did not exceed standards or criteria for humans, freshwater life, or beneficial uses of the water. In water, the herbicide 2,4-D was detected more than any other pesticide and in concentrations from 0.01 to 1.0 microgram per liter. In bottom sediment, organochlorine insecticides were detected in samples from 19 of 21 sites. In fish collected from some wasteways, chlordane, DDT, and dieldrin concentrations occasionally exceeded freshwater protection criteria.

  7. Initial Impacts of the Mount Polley Tailings Pond Breach on Adjacent Aquatic Ecosystems

    NASA Astrophysics Data System (ADS)

    Petticrew, Ellen; Gantner, Nikolaus; Albers, Sam; Owens, Philip

    2015-04-01

    On August 4th 2014, the Mount Polley Tailings pond breach near Likely, B.C., released approximately 24 million cubic metres of tailings material into Polley Lake, Hazeltine Creek and Quesnel Lake. The discharge scoured and eroded a swath of soil and sediment delivering an unknown amount of metals and sediment into this tributary ecosystem of the Fraser River. Subsequent efforts by the mine operator to remediate by pumping tailings water from Polley Lake into Hazeltine Creek, which flows into Quesnel Lake, resulted in additional and continuous release of unknown volumes of contaminated water and sediments into the watershed. Heavy metals (e.g., selenium, copper, or mercury) reported as stored in the tailings pond entered the downstream aquatic environment and have been monitored in the water column of Quesnel Lake since August. These contaminants are likely particle-bound and thus subject to transport over long distances without appreciable degradation, resulting in the potential for chronic exposures and associated toxicological effects in exposed biota. While significant dilution is expected during aquatic transport, and the resulting concentrations in the water will likely be low, concentrations in exposed biota may become of concern over time. Metals such as mercury and selenium undergo bioaccumulation and biomagnification, once incorporated into the food chain/web. Thus, even small concentrations of such contaminants in water can lead to greater concentrations (~100 fold) in top predators. Over time, our predictions are that food web transfer will lead to an increase in concentrations from water (1-2 years)->invertebrates (1-2 yrs) ->fishes (2-5 yrs). Pacific salmon travel great distances in this watershed and may be exposed to contaminated water during their migrations. Resident species will be exposed to the contaminated waters and sediments in the study lakes year round. Little or no background/baseline data for metals in biota from Quesnel Lake exists

  8. Wastewater indicator compounds in wastewater effluent, surface water, and bed sediment in the St. Croix National Scenic Riverway and implications for water resources and aquatic biota, Minnesota and Wisconsin, 2007-08

    USGS Publications Warehouse

    Tomasek, Abigail A.; Lee, Kathy E.; Hansen, Donald S.

    2012-01-01

    The results of this study indicate that aquatic biota in the St. Croix River are exposed to a wide variety of organic contaminants that originate from diverse sources including WWTP effluent. The data on wastewater indicator compounds indicate that exposures are temporally and spatially variable and that OWCs may accumulate in bed sediment. These results also indicate that OWCs in water and bed sediment increase downstream from discharges of wastewater effluent to the St. Croix River; however, the presence of OWCs in surface water and bed sediment at the Sunrise site indicates that potential sources of compounds, such as WWTPs or other sources, are upstream from the Taylors Falls-St. Croix Falls area.

  9. Use of enzymatic tools for biomonitoring inorganic pollution in aquatic sediments: a case study (Bor, Serbia)

    PubMed Central

    2013-01-01

    Background Sediment bacterial communities are key players in biogeochemical cycling of elements in the aquatic environment. Copper mining, smelting, and processing operations located in Bor area (Serbia) are major environmental hot spots in the lower Danube Basin and Western Balkans. In the present study, we evaluate the influence of trace element (TE) concentration in sediments and physico-chemical properties of water on sediment microbial communities in water streams adjacent to the Copper Smelter Complex Bor (RTB Bor, Serbia). The degree to which metabolic activities of bacterial biota inhabiting differently polluted sites is inhibited by inorganic pollution were compared using selected enzymatic bioindicators. Results Cu, Zn, Pb, and As concentrations systematically exceeded the target values for metal loadings in aquatic sediments. Water electrical conductivity (WEC) followed the same pattern of spatial variation, irrespective of season. Interestingly, the most intense enzymatic activity occurred at the reference site although this site showed the greatest TE levels in aquatic sediments. Catalase activity (CA), potential dehydrogenase activity (PDA), actual dehydrogenase activity (ADA), urease activity (UA), and phosphatase activity (PA) in aquatic sediments displayed heterogeneous patterns of spatio-temporal variation. Inorganic pollution greatly affected CA, ADA, and PDA, but much less so UA and PA. Canonical correlation analysis showed that pH and WEC were the strongest determinants of enzymatic activity in bacterial biota, with the latter variable being reversely correlated with the enzymatic indicator of sediment quality (EISQ). The median values of EISQ increased with distance from the major sources of pollution. In addition, it was found that sites with different degrees of inorganic pollution can be appropriately classified by applying cluster analysis to EISQ, TE levels in sediments, and physico-chemical properties of water. Conclusions Because EISQ

  10. Fate and risks of nanomaterials in aquatic and terrestrial environments.

    PubMed

    Batley, Graeme E; Kirby, Jason K; McLaughlin, Michael J

    2013-03-19

    interact with nanoparticles to change surface charge and mobility and affect the interactions of those nanoparticles with biota. Ultimately, aquatic nanomaterials accumulate in bottom sediments, facilitated in natural systems by heteroaggregation. Homoaggregates of nanoparticles sediment more slowly. Nanomaterials from urban, medical, and industrial sources may undergo significant transformations during wastewater treatment processes. For example, sulfidation of silver nanoparticles in wastewater treatment systems converts most of the nanoparticles to silver sulfides (Ag₂S). Aggregation of the nanomaterials with other mineral and organic components of the wastewater often results in most of the nanomaterial being associated with other solids rather than remaining as dispersed nanosized suspensions. Risk assessments for nanomaterial releases to the environment are still in their infancy, and reliable measurements of nanomaterials at environmental concentrations remain challenging. Predicted environmental concentrations based on current usage are low but are expected to increase as use increases. At this early stage, comparisons of estimated exposure data with known toxicity data indicate that the predicted environmental concentrations are orders of magnitude below those known to have environmental effects on biota. As more toxicity data are generated under environmentally-relevant conditions, risk assessments for nanomaterials will improve to produce accurate assessments that assure environmental safety.

  11. Hydrogeomorphology explains acidification-driven variation in aquatic biological communities in the Neversink Basin, USA

    USGS Publications Warehouse

    Harpold, Adrian A.; Burns, Douglas A.; Walter, M.T.; Steenhuis, Tammo S.

    2013-01-01

    Describing the distribution of aquatic habitats and the health of biological communities can be costly and time-consuming; therefore, simple, inexpensive methods to scale observations of aquatic biota to watersheds that lack data would be useful. In this study, we explored the potential of a simple “hydrogeomorphic” model to predict the effects of acid deposition on macroinvertebrate, fish, and diatom communities in 28 sub-watersheds of the 176-km2 Neversink River basin in the Catskill Mountains of New York State. The empirical model was originally developed to predict stream-water acid neutralizing capacity (ANC) using the watershed slope and drainage density. Because ANC is known to be strongly related to aquatic biological communities in the Neversink, we speculated that the model might correlate well with biotic indicators of ANC response. The hydrogeomorphic model was strongly correlated to several measures of macroinvertebrate and fish community richness and density, but less strongly correlated to diatom acid tolerance. The model was also strongly correlated to biological communities in 18 sub-watersheds independent of the model development, with the linear correlation capturing the strongly acidic nature of small upland watersheds (2). Overall, we demonstrated the applicability of geospatial data sets and a simple hydrogeomorphic model for estimating aquatic biological communities in areas with stream-water acidification, allowing estimates where no direct field observations are available. Similar modeling approaches have the potential to complement or refine expensive and time-consuming measurements of aquatic biota populations and to aid in regional assessments of aquatic health.

  12. A meta-analysis of the effects of exposure to microplastics on fish and aquatic invertebrates.

    PubMed

    Foley, Carolyn J; Feiner, Zachary S; Malinich, Timothy D; Höök, Tomas O

    2018-08-01

    Microplastics are present in aquatic ecosystems the world over and may influence the feeding, growth, reproduction, and survival of freshwater and marine biota; however, the extent and magnitude of potential effects of microplastics on aquatic organisms is poorly understood. In the current study, we conducted a meta-analysis of published literature to examine impacts of exposure to microplastics on consumption (and feeding), growth, reproduction, and survival of fish and aquatic invertebrates. While we did observe within-taxa negative effects for all four categories of responses, many of the effects summarized in our study were neutral, indicating that the effects of exposure to microplastics are highly variable across taxa. The most consistent effect was a reduction in consumption of natural prey when microplastics were present. For some taxa, negative effects on growth, reproduction and even survival were also evident. Organisms that serve as prey to larger predators, e.g., zooplankton, may be particularly susceptible to negative impacts of exposure to microplastic pollution, with potential for ramifications throughout the food web. Future work should focus on whether microplastics may be affecting aquatic organisms more subtly, e.g., by influencing exposure to contaminants and pathogens, or by acting at a molecular level. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. TOXICITY OF DIETBOURNE METALS IN AQUATIC BIOTA: EMERGING SCIENCE AND REGULATORY IMPLICATIONS

    EPA Science Inventory

    A Pellston Workshop entitled "The Role of Dietborne Exposures in the Evaluation of Risk of Metals to Aquatic Organisms" was held in July 2002. The workshop was organized by SETAC, with funding from several government and industry organizations. The objective was to examine key ...

  14. A probabilistic model for silver bioaccumulation in aquatic systems and assessment of human health risks

    USGS Publications Warehouse

    Warila, James; Batterman, Stuart; Passino-Reader, Dora R.

    2001-01-01

    Silver (Ag) is discharged in wastewater effluents and is also a component in a proposed secondary water disinfectant. A steady-state model was developed to simulate bioaccumulation in aquatic biota and assess ecological and human health risks. Trophic levels included phytoplankton, invertebrates, brown trout, and common carp. Uptake routes included water, food, or sediment. Based on an extensive review of the literature, distributions were derived for most inputs for use in Monte Carlo simulations. Three scenarios represented ranges of dilution and turbidity. Compared with the limited field data available, median estimates of Ag in carp (0.07-2.1 Iμg/g dry weight) were 0.5 to 9 times measured values, and all measurements were within the predicted interquartile range. Median Ag concentrations in biota were ranked invertebrates > phytoplankton > trout > carp. Biotic concentrations were highest for conditions of low dilution and low turbidity. Critical variables included Ag assimilation eficiency, specific feeding rate, and the phytoplankton bioconcentration factor. Bioaccumulation of Ag seems unlikely to result in txicity to aquatic biota and humans consuming fish. Although the highest predicted Ag concentrations in water (>200 ng/L) may pose chronic risks to early survival and development of salmonids and risks of argyria to subsistence fishers, these results occur under highly conservative conditions.

  15. Review of emerging contaminants in aquatic biota from Latin America: 2002-2016.

    PubMed

    Llorca, Marta; Farré, Marinella; Eljarrat, Ethel; Díaz-Cruz, Sílvia; Rodríguez-Mozaz, Sara; Wunderlin, Daniel; Barcelo, Damià

    2017-07-01

    Although it is known that emerging contaminants are widespread all over the globe, there is a gap of information about their distribution in some geographical areas, such as Latin America. The present bibliographic work reviews the available literature about the presence of organic emerging contaminants in Latin American freshwater and marine biota between 2002 and 2016 and includes 23 works from Argentina, Brazil, Chile, Colombia, Mexico, and Nicaragua. In particular, the present review provides an overview of the occurrence of continuously present contaminants such as pharmaceuticals, personal care products, and pyrethroid insecticides, as well as the new groups of persistent organic pollutants, the halogenated flame retardants and the perfluoroalkyl substances. A wide overview is provided, considering not only occurrence data but also effects and potential transfer through the food chain. Environ Toxicol Chem 2017;36:1716-1727. © 2016 SETAC. © 2016 SETAC.

  16. Late Cretaceous Aquatic Plant World in Patagonia, Argentina

    PubMed Central

    Cúneo, N. Rubén; Gandolfo, María A.; Zamaloa, María C.; Hermsen, Elizabeth

    2014-01-01

    In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla) and a monocot (Araceae). Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae). Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form) and the eudicot angiosperm Nelumbo (Nelumbonaceae) are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae), ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America. PMID:25148081

  17. Environmental risk assessment of three selective serotonin reuptake inhibitors in the aquatic environment: a case study including a cocktail scenario.

    PubMed

    Styrishave, Bjarne; Halling-Sørensen, Bent; Ingerslev, Flemming

    2011-01-01

    We present an environmental risk assessment of three selective serotonin reuptake inhibitors (SSRIs; citalopram, sertraline, and fluoxetine) in the aquatic environment based on two case scenarios. Abiotic and biotic degradation experiments and sorption estimates were used to predict environmental concentrations of three SSRIs from the wastewater of two psychiatric hospitals, the primary sector, and wastewater entering and leaving wastewater treatment plants (WWTPs). Assuming a sewage treatment retention time of 8 h, abiotic degradation was low, for all three SSRIs inhibitors, ranging between 0 and 2% for hydrolysis and 0 and 6% for photolysis. The biodegradation was also slow, ranging from 0 to 3% within an 8-h period. In untreated sewage, citalopram (CIT) and sertraline (SER) concentrations may be high enough to exert effects on the aquatic biota (CIT: 0.19-10.3 µg/L; SER: 0.14-17.1 µg/L). Removal of the pharmaceuticals is due primarily to sorption in the WWTP. Sertraline was estimated to have the highest concentrations in the sewage effluents, 4.4 and 19.9 ng/L for the two cases, respectively. In treated wastewater, individual SSRI concentrations are probably too low to exert effects on biota. By using concentration addition, a cocktail exposure scenario was estimated. The predicted concentration in the biota calculated from the cocktail effect was 0.05 and 0.16 nmol/g for the two cases, respectively, and SER was found to give the highest contribution to this cocktail effect. The results indicate that the concentrations in the wastewater effluents are one to two orders of magnitude lower than the concentrations likely to cause an effect in the aquatic biota. © 2010 SETAC.

  18. Fuzzy logic modeling of bioaccumulation pattern of metals in coastal biota of Ondo State, Nigeria.

    PubMed

    Agunbiade, Foluso O; Olu-Owolabi, Bamidele I; Adebowale, Kayode O

    2012-01-01

    The accumulation patterns of ten metals in tissues of plant, Eichornia crassipes, and fishes, Hydrocynus forskahlii and Oreochromis mossambicus, were modeled with simple fuzzy classification (SFC) to assess toxic effects of anthropogenic activities on the coastal biota. The plant sample was separated into root, stem, and leaves and the fishes into bones, internal tissues, and muscles. They were analyzed for As, Cd, Cr, Cu, Ni, Pb, V, Fe, Mn, and Zn after wet oxidation of their dried samples. The results were converted into membership functions of five accumulation classes and aggregated with SFC. The classification results showed that there was no metal accumulation in the plant parts while the fishes were classified into low accumulation category. The internal tissues of the fishes had higher metal accumulation than the other parts. Generally, Fe and Mn had highest concentrations in the biota but are natural to the area and may not constitute significant risk. Cr had the highest transfer and accumulation from the coastal water into the aquatic lives and may be indicative of risk prone system being a toxic metal. Metal contaminations in the zone had not significantly accumulated in the biota making them less prone to risk associated with metal accumulation.

  19. Microplastics as vectors for environmental contaminants: Exploring sorption, desorption, and transfer to biota.

    PubMed

    Hartmann, Nanna B; Rist, Sinja; Bodin, Julia; Jensen, Louise Hs; Schmidt, Stine N; Mayer, Philipp; Meibom, Anders; Baun, Anders

    2017-05-01

    The occurrence and effects of microplastics (MPs) in the aquatic environment are receiving increasing attention. In addition to their possible direct adverse effects on biota, the potential role of MPs as vectors for hydrophobic organic chemicals (HOCs), compared to natural pathways, is a topic of much debate. It is evident, however, that temporal and spatial variations of MP occurrence do (and will) occur. To further improve the estimations of the role of MPs as vectors for HOC transfer into biota under varying MP concentrations and environmental conditions, it is important to identify and understand the governing processes. Here, we explore HOC sorption to and desorption from MPs and the underlying principles for their interactions. We discuss intrinsic and extrinsic parameters influencing these processes and focus on the importance of the exposure route for diffusive mass transfer. Also, we outline research needed to fill knowledge gaps and improve model-based calculations of MP-facilitated HOC transfer in the environment. Integr Environ Assess Manag 2017;13:488-493. © 2017 SETAC. © 2017 SETAC.

  20. Developing a novel approach to analyse the regimes of temporary streams and their controls on aquatic biota

    NASA Astrophysics Data System (ADS)

    Gallart, F.; Prat, N.; García-Roger, E. M.; Latron, J.; Rieradevall, M.; Llorens, P.; Barberá, G. G.; Brito, D.; de Girolamo, A. M.; Lo Porto, A.; Neves, R.; Nikolaidis, N. P.; Perrin, J. L.; Querner, E. P.; Quiñonero, J. M.; Tournoud, M. G.; Tzoraki, O.; Froebrich, J.

    2011-10-01

    Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. The use of the aquatic fauna structural and functional characteristics to assess the ecological quality of a temporary stream reach can not therefore be made without taking into account the controls imposed by the hydrological regime. This paper develops some methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: flood, riffles, connected, pools, dry and arid. We used the water discharge records from gauging stations or simulations using rainfall-runoff models to infer the temporal patterns of occurrence of these states using the developed aquatic states frequency graph. The visual analysis of this graph is complemented by the development of two metrics based on the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of the aquatic regimes of temporary streams in terms of their influence over the development of aquatic life is put forward, defining Permanent, Temporary-pools, Temporary-dry and Episodic regime types. All these methods were tested with data from eight temporary streams around the Mediterranean from MIRAGE project and its application was a precondition to assess the ecological quality of these streams using the current methods prescribed in the European Water Framework Directive for macroinvertebrate communities.

  1. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in and near Humboldt Wildlife Management Area, Churchill and Pershing Counties, Nevada, 1990-91

    USGS Publications Warehouse

    Seiler, R.L.; Ekechukwu, G.A.; Hallock, R.J.

    1993-01-01

    A reconnaissance investigation was begun in 1990 to determine whether the quality of irrigation drainage in and near the Humboldt Wildlife Management Area, Nevada, has caused or has the potential to cause harmful effects on human health, fish, and wildlife or to impair beneficial uses of water. Samples of surface and ground water, bottom sediment, and biota collected from sites upstream and downstream from the Lovelock agricultural area were analyzed for potentially toxic trace elements. Also analyzed were radioactive substances, major dissolved constitu- ents, and nutrients in water, as well as pesticide residues in bottom sediment and biota. In samples from areas affected by irrigation drainage, the following constituents equaled or exceeded baseline concentrations or recommended standards for protection of aquatic life or propagation of wildlife--in water: arsenic, boron, dissolved solids, mercury, molybdenum, selenium, sodium, and un-ionized ammonia; in bottom sediment; arsenic and uranium; and in biota; arsenic, boron, and selenium. Selenium appears to be biomagnified in the Humboldt Sink wetlands. Biological effects observed during the reconnaissance included reduced insect diversity in sites receiving irrigation drainage and acute toxicity of drain water and sediment to test organisms. The current drought and upstream consumption of water for irrigation have reduced water deliveries to the wetlands and caused habitat degradation at Humboldt Wildlife Management Area. During this investigation. Humboldt and Toulon Lakes evaporated to dryness because of the reduced water deliveries.

  2. Biota-Sediment Accumulation Factor Data

    EPA Pesticide Factsheets

    The Biota-Sediment Accumulation Factor contains approximately 20,000 biota-sediment accumulation factors (BSAFs) from 20 locations (mostly Superfund sites) for nonionic organic chemicals and pesticides. Fresh, tidal, and marine ecosystems are included in the data.

  3. Aquatic community structure in Mediterranean edge-of-field waterbodies as explained by environmental factors and the presence of pesticide mixtures.

    PubMed

    Pereira, Ana Santos; Dâmaso-Rodrigues, Maria Luísa; Amorim, Ana; Daam, Michiel A; Cerejeira, Maria José

    2018-06-16

    Studies addressing the predicted effects of pesticides in combination with abiotic and biotic factors on aquatic biota in ditches associated with typical Mediterranean agroecosystems are scarce. The current study aimed to evaluate the predicted effects of pesticides along with environmental factors and biota interactions on macroinvertebrate, zooplankton and phytoplankton community compositions in ditches adjacent to Portuguese maize and tomato crop areas. Data was analysed with the variance partitioning procedure based on redundancy analysis (RDA). The total variance in biological community composition was divided into the variance explained by the multi-substance potentially affected fraction [(msPAF) arthropods and primary producers], environmental factors (water chemistry parameters), biotic interactions, shared variance, and unexplained variance. The total explained variance reached 39.4% and the largest proportion of this explained variance was attributed to msPAF (23.7%). When each group (phytoplankton, zooplankton and macroinvertebrates) was analysed separately, biota interactions and environmental factors explained the largest proportion of variance. Results of this study indicate that besides the presence of pesticide mixtures, environmental factors and biotic interactions also considerably influence field freshwater communities. Subsequently, to increase our understanding of the risk of pesticide mixtures on ecosystem communities in edge-of-field water bodies, variations in environmental and biological factors should also be considered.

  4. Solar Energy Development and Aquatic Ecosystems in the Southwestern United States: Potential Impacts, Mitigation, and Research Needs

    NASA Astrophysics Data System (ADS)

    Grippo, Mark; Hayse, John W.; O'Connor, Ben L.

    2015-01-01

    The cumulative impacts of utility-scale solar energy facilities on aquatic ecosystems in the Southwestern United States are of concern, considering the many existing regional anthropogenic stressors. We review the potential impacts of solar energy development on aquatic habitat and biota. The greatest potential for impacts is related to the loss, fragmentation, or prolonged drying of ephemeral water bodies and drainage networks resulting from the loss of desert washes within the construction footprint of the facility. Groundwater-dependent aquatic habitat may also be affected by operational groundwater withdrawal in the case of water-intensive solar technologies. Solar panels have also been found to attract aquatic insects and waterbirds, potentially resulting in mortality. Avoiding construction activity near perennial and intermittent surface waters is the primary means of reducing impacts on aquatic habitats, followed by measures to minimize erosion, sedimentation, and contaminant inputs into waterways. Currently, significant data gaps make solar facility impact assessment and mitigation more difficult. Examples include the need for more regional and site-specific studies of surface-groundwater connectivity, more detailed maps of regional stream networks and riparian vegetation corridors, as well as surveys of the aquatic communities inhabiting ephemeral streams. In addition, because they often lack regulatory protection, there is also a need to develop valuation criteria for ephemeral waters based on their ecological and hydrologic function within the landscape. By addressing these research needs, we can achieve the goal of greater reliance on solar energy, while at the same time minimizing impacts on desert ecosystems.

  5. Solar energy development and aquatic ecosystems in the southwestern United States: potential impacts, mitigation, and research needs.

    PubMed

    Grippo, Mark; Hayse, John W; O'Connor, Ben L

    2015-01-01

    The cumulative impacts of utility-scale solar energy facilities on aquatic ecosystems in the Southwestern United States are of concern, considering the many existing regional anthropogenic stressors. We review the potential impacts of solar energy development on aquatic habitat and biota. The greatest potential for impacts is related to the loss, fragmentation, or prolonged drying of ephemeral water bodies and drainage networks resulting from the loss of desert washes within the construction footprint of the facility. Groundwater-dependent aquatic habitat may also be affected by operational groundwater withdrawal in the case of water-intensive solar technologies. Solar panels have also been found to attract aquatic insects and waterbirds, potentially resulting in mortality. Avoiding construction activity near perennial and intermittent surface waters is the primary means of reducing impacts on aquatic habitats, followed by measures to minimize erosion, sedimentation, and contaminant inputs into waterways. Currently, significant data gaps make solar facility impact assessment and mitigation more difficult. Examples include the need for more regional and site-specific studies of surface-groundwater connectivity, more detailed maps of regional stream networks and riparian vegetation corridors, as well as surveys of the aquatic communities inhabiting ephemeral streams. In addition, because they often lack regulatory protection, there is also a need to develop valuation criteria for ephemeral waters based on their ecological and hydrologic function within the landscape. By addressing these research needs, we can achieve the goal of greater reliance on solar energy, while at the same time minimizing impacts on desert ecosystems.

  6. Aquatic biodiversity in forests: A weak link in ecosystem services resilience

    USGS Publications Warehouse

    Penaluna, Brooke E.; Olson, Deanna H.; Flitcroft, Rebecca L; Weber, Matthew A.; Bellmore, J. Ryan; Wondzell, Steven M.; Dunham, Jason B.; Johnson, Sherri L.; Reeves, Gordon H.

    2017-01-01

    The diversity of aquatic ecosystems is being quickly reduced on many continents, warranting a closer examination of the consequences for ecological integrity and ecosystem services. Here we describe intermediate and final ecosystem services derived from aquatic biodiversity in forests. We include a summary of the factors framing the assembly of aquatic biodiversity in forests in natural systems and how they change with a variety of natural disturbances and human-derived stressors. We consider forested aquatic ecosystems as a multi-state portfolio, with diverse assemblages and life-history strategies occurring at local scales as a consequence of a mosaic of habitat conditions and past disturbances and stressors. Maintaining this multi-state portfolio of assemblages requires a broad perspective of ecosystem structure, various functions, services, and management implications relative to contemporary stressors. Because aquatic biodiversity provides multiple ecosystem services to forests, activities that compromise aquatic ecosystems and biodiversity could be an issue for maintaining forest ecosystem integrity. We illustrate these concepts with examples of aquatic biodiversity and ecosystem services in forests of northwestern North America, also known as Northeast Pacific Rim. Encouraging management planning at broad as well as local spatial scales to recognize multi-state ecosystem management goals has promise for maintaining valuable ecosystem services. Ultimately, integration of information from socio-ecological ecosystems will be needed to maintain ecosystem services derived directly and indirectly from forest aquatic biota.

  7. Toxicity of ferric chloride sludge to aquatic organisms.

    PubMed

    Sotero-Santos, Rosana B; Rocha, Odete; Povinelli, Jurandyr

    2007-06-01

    Iron-rich sludge from a drinking water treatment plant (DWTP) was investigated regarding its toxicity to aquatic organisms and physical and chemical composition. In addition, the water quality of the receiving stream near the DWTP was evaluated. Experiments were carried out in August 1998, February 1999 and May 1999. Acute toxicity tests were carried out on a cladoceran (Daphnia similis), a midge (Chironomus xanthus) and a fish (Hyphessobrycon eques). Chronic tests were conducted only on D. similis. Acute sludge toxicity was not detected using any of the aquatic organisms, but chronic effects were observed upon the fecundity of D. similis. Although there were relatively few sample dates, the results suggested that the DWTP sludge had a negative effect on the receiving body as here was increased suspended matter, turbidity, conductivity, chemical oxygen demand (COD) and hardness in the water downstream of the DWTP effluent discharge. The ferric chloride sludge also exhibited high heavy metal concentrations revealing a further potential for pollution and harmful chronic effects on the aquatic biota when the sludge is disposed of without previous treatment.

  8. Water-quality assessment of the upper Illinois River Basin in Illinois, Indiana, and Wisconsin; major and trace elements in water, sediment, and biota, 1978-90

    USGS Publications Warehouse

    Fitzpatrick, F.A.; Scudder, B.C.; Crawford, J.K.; Schmidt, A.R.; Sieverling, J.B.

    1995-01-01

    The distribution of 22 major and trace elements was examined in water, sediment, and biota in the upper Illinois River Basin in Illinois, Indiana, and Wisconsin as part of a pilot National Water-Quality Assessment project done by the U.S. Geological Survey from 1987 through 1990. The 22 elements are aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, molybdenum, nickel, phosphorus, selenium, silver, strontium, vanadium, and zinc. Concentrations of U.S. Environmental Protection Agency (USEPA) priority pollutants among the 22 elements were elevated in the Chicago area in all three aquatic components (water, sediment, and biota). Further, some of the priority pollutants also were found at elevated concentrations in biota in agricultural areas in the basin. Cadmium, chromium, copper, iron, lead, mercury, silver, and zinc concentrations in water exceeded USEPA acute or chronic water-quality criteria at several sites in the Chicago area. Correlations among concentra- tions of elements in water, sediment, and biota were found, but the correlation analysis was hindered by the large proportion of observations less than the minimum reporting level in water. Those sites where water-quality criteria were sometimes exceeded were not always the same sites where concentrations in biota were the largest. This relation indicates that accumulation of these pollutants in biota is confounded by complex geochemical and biological processes that differ throughout the upper Illinois River Basin.

  9. Realized niche width of a brackish water submerged aquatic vegetation under current environmental conditions and projected influences of climate change.

    PubMed

    Kotta, Jonne; Möller, Tiia; Orav-Kotta, Helen; Pärnoja, Merli

    2014-12-01

    Little is known about how organisms might respond to multiple climate stressors and this lack of knowledge limits our ability to manage coastal ecosystems under contemporary climate change. Ecological models provide managers and decision makers with greater certainty that the systems affected by their decisions are accurately represented. In this study Boosted Regression Trees modelling was used to relate the cover of submerged aquatic vegetation to the abiotic environment in the brackish Baltic Sea. The analyses showed that the majority of the studied submerged aquatic species are most sensitive to changes in water temperature, current velocity and winter ice scour. Surprisingly, water salinity, turbidity and eutrophication have little impact on the distributional pattern of the studied biota. Both small and large scale environmental variability contributes to the variability of submerged aquatic vegetation. When modelling species distribution under the projected influences of climate change, all of the studied submerged aquatic species appear to be very resilient to a broad range of environmental perturbation and biomass gains are expected when seawater temperature increases. This is mainly because vegetation develops faster in spring and has a longer growing season under the projected climate change scenario. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Accumulation of radionuclides in selected marine biota from Manjung coastal area

    NASA Astrophysics Data System (ADS)

    Abdullah, Anisa; Hamzah, Zaini; Saat, Ahmad; Wood, Ab. Khalik; Alias, Masitah

    2015-04-01

    Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marine biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 (226Ra), radium-228 (228Ra) and potassium-40 (40K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (Hin), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption.

  11. Mercury Accumulation in Biota of Tributaries of the Finger Lakes, New York

    NASA Astrophysics Data System (ADS)

    Cleckner, L.; Razavi, R.; Cushman, S. F.; Massey, T.

    2016-12-01

    Mercury (Hg) is an aquatic pollutant whose availability to a given waterbody is closely tied to watershed characteristics. Transport of Hg from watersheds to waterbodies is controlled primarily by dissolved organic carbon (DOC) and suspended particulate matter. This study was conducted to assess accumulation of Hg in biota of tributaries of five Finger Lakes watersheds in New York, USA. Very little is known regarding Hg dynamics within Finger Lakes stream food webs or how tributaries contribute to Hg transport to the lakes themselves. Sources of Hg in the region include atmospheric pollution from an active coal-fired power plant. Between May and October 2015, two species of stream fish (Blacknose Dace, Rhinichthys atratulus, and Creek Chub, Semotilus atromaculatus) were collected by backpack electrofishing. At the same time, benthic macroinvertebrates representing various feeding groups and periphyton were collected for methylmercury determination. Samples for suspended particulate matter, DOC, and specific ultraviolet absorbance were also collected. The study objectives were to determine 1) whether differences existed in fish biota Hg concentrations among lake watersheds, and 2) the influence of DOC and land use on observed biota Hg accumulation patterns. Preliminary analyses of fish Hg results indicate a difference in accumulation between the two indicator species selected. Mercury concentrations were found to increase with fish size. Across all lake watersheds, Creek Chub were found to be significantly larger than Blacknose Dace. However, there was no significant difference in Hg concentrations between the two species. A within watershed analysis of five Seneca Lake tributaries showed that average Hg concentrations were significantly higher in Blacknose Dace than Creek Chub. This suggests this species is more vulnerable to Hg accumulation and a better indicator of Hg availability. No significant differences were found in Creek Chub Hg concentrations among

  12. Assessment of mercury and methylmercury in water, sediment, and biota in Sulphur Creek in the vicinity of the Clyde Gold Mine and the Elgin Mercury Mine, Colusa County, California

    USGS Publications Warehouse

    Hothem, Roger L.; Rytuba, James J.; Brussee, Brianne E.; Goldstein, Daniel N.

    2013-01-01

    At the request of the U.S. Bureau of Land Management, we performed a study during April–July 2010 to characterize mercury (Hg), monomethyl mercury (MMeHg), and other geochemical constituents in sediment, water, and biota at the Clyde Gold Mine and the Elgin Mercury Mine, located in neighboring subwatersheds of Sulphur Creek, Colusa County, California. This study was in support of a Comprehensive Environmental Response, Compensation, and Liability Act - Removal Site Investigation. The investigation was in response to an abatement notification from the California Central Valley Regional Water Quality Control Board to evaluate the release of Hg from the Clyde and Elgin mines. Samples of water, sediment, and biota (aquatic macroinvertebrates) were collected from sites upstream and downstream from the two mine sites to evaluate the level of Hg contamination contributed by each mine to the aquatic ecosystem. Physical parameters, as well as dissolved organic carbon, total Hg (HgT), and MMeHg were analyzed in water and sediment. Other relevant geochemical constituents were analyzed in sediment, filtered water, and unfiltered water. Samples of aquatic macroinvertebrates from each mine were analyzed for HgT and MMeHg. The presence of low to moderate concentrations of HgT and MMeHg in water, sediment, and biota from the Freshwater Branch of Sulphur Creek, and the lack of significant increases in these concentrations downstream from the Clyde Mine indicated that this mine is not a significant source of Hg to the watershed during low flow conditions. Although concentrations of HgT and MMeHg were generally higher in samples of sediment and water from the Elgin Mine compared to the Clyde Mine, concentrations in comparable biota from the two mine areas were similar. It is likely that highly saline effluent from nearby hot springs contribute more Hg to the West Fork of Sulphur Creek than the mine waste material at the Elgin Mine.

  13. Landscape level influence: aquatic primary production in the Colorado River of Glen and Grand canyons

    NASA Astrophysics Data System (ADS)

    Yard, M. D.; Kennedy, T.; Yackulic, C. B.; Bennett, G. E.

    2012-12-01

    Irregular features common to canyon-bound regions intercept solar incidence (photosynthetic photon flux density [PPFD: μmol m-2 s-1]) and can affect ecosystem energetics. The Colorado River in Grand Canyon is topographically complex, typical of most streams and rivers in the arid southwest. Dam-regulated systems like the Colorado River have reduced sediment loads, and consequently increased water transparency relative to unimpounded rivers; however, sediment supply from tributaries and flow regulation that affects erosion and subsequent sediment transport, interact to create spatial and temporal variation in optical conditions in this river network. Solar incidence and suspended sediment loads regulate the amount of underwater light available for aquatic photosynthesis in this regulated river. Since light availability is depth dependent (Beer's law), benthic algae is often exposed to varying levels of desiccation or reduced light conditions due to daily flow regulation, additional factors that further constrain aquatic primary production. Considerable evidence suggests that the Colorado River food web is now energetically dependent on autotrophic production, an unusual condition since large river foodwebs are typically supported by allochthonous carbon synthesized and transported from terrestrial environments. We developed a mechanistic model to account for these regulating factors to predict how primary production might be affected by observed and alternative flow regimes proposed as part of ongoing adaptive management experimentation. Inputs to our model include empirical data (suspended sediment and temperature), and predictive relationships: 1) solar incidence reaching the water surface (topographic complexity), 2) suspended sediment-light extinction relationships (optical properties), 3) unsteady flow routing model (stage-depth relationship), 4) channel morphology (photosynthetic area), and 5) photosynthetic-irradiant response for dominant algae (Cladophora

  14. Accumulation of radionuclides in selected marine biota from Manjung coastal area

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Abdullah, Anisa, E-mail: coppering@ymail.com; Hamzah, Zaini; Wood, Ab. Khalik

    Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marinemore » biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 ({sup 226}Ra), radium-228 ({sup 228}Ra) and potassium-40 ({sup 40}K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (H{sub in}), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption.« less

  15. Global analysis of depletion and recovery of seabed biota after bottom trawling disturbance.

    PubMed

    Hiddink, Jan Geert; Jennings, Simon; Sciberras, Marija; Szostek, Claire L; Hughes, Kathryn M; Ellis, Nick; Rijnsdorp, Adriaan D; McConnaughey, Robert A; Mazor, Tessa; Hilborn, Ray; Collie, Jeremy S; Pitcher, C Roland; Amoroso, Ricardo O; Parma, Ana M; Suuronen, Petri; Kaiser, Michel J

    2017-08-01

    Bottom trawling is the most widespread human activity affecting seabed habitats. Here, we collate all available data for experimental and comparative studies of trawling impacts on whole communities of seabed macroinvertebrates on sedimentary habitats and develop widely applicable methods to estimate depletion and recovery rates of biota after trawling. Depletion of biota and trawl penetration into the seabed are highly correlated. Otter trawls caused the least depletion, removing 6% of biota per pass and penetrating the seabed on average down to 2.4 cm, whereas hydraulic dredges caused the most depletion, removing 41% of biota and penetrating the seabed on average 16.1 cm. Median recovery times posttrawling (from 50 to 95% of unimpacted biomass) ranged between 1.9 and 6.4 y. By accounting for the effects of penetration depth, environmental variation, and uncertainty, the models explained much of the variability of depletion and recovery estimates from single studies. Coupled with large-scale, high-resolution maps of trawling frequency and habitat, our estimates of depletion and recovery rates enable the assessment of trawling impacts on unprecedented spatial scales.

  16. Global analysis of depletion and recovery of seabed biota after bottom trawling disturbance

    PubMed Central

    Hiddink, Jan Geert; Jennings, Simon; Sciberras, Marija; Szostek, Claire L.; Hughes, Kathryn M.; Ellis, Nick; Rijnsdorp, Adriaan D.; McConnaughey, Robert A.; Mazor, Tessa; Hilborn, Ray; Collie, Jeremy S.; Pitcher, C. Roland; Amoroso, Ricardo O.; Parma, Ana M.; Suuronen, Petri; Kaiser, Michel J.

    2017-01-01

    Bottom trawling is the most widespread human activity affecting seabed habitats. Here, we collate all available data for experimental and comparative studies of trawling impacts on whole communities of seabed macroinvertebrates on sedimentary habitats and develop widely applicable methods to estimate depletion and recovery rates of biota after trawling. Depletion of biota and trawl penetration into the seabed are highly correlated. Otter trawls caused the least depletion, removing 6% of biota per pass and penetrating the seabed on average down to 2.4 cm, whereas hydraulic dredges caused the most depletion, removing 41% of biota and penetrating the seabed on average 16.1 cm. Median recovery times posttrawling (from 50 to 95% of unimpacted biomass) ranged between 1.9 and 6.4 y. By accounting for the effects of penetration depth, environmental variation, and uncertainty, the models explained much of the variability of depletion and recovery estimates from single studies. Coupled with large-scale, high-resolution maps of trawling frequency and habitat, our estimates of depletion and recovery rates enable the assessment of trawling impacts on unprecedented spatial scales. PMID:28716926

  17. EXOTIC AND INVASIVE AQUATIC PLANTS IN GREAT LAKES COASTAL WETLANDS: DISTRIBUTION AND RELATION TO WATERSHED LAND USE AND PLANT RICHNESS AND COVER

    EPA Science Inventory

    This manuscript provides previously unavailable information to researchers and managers concerning exotic plants in the Great Lakes...This work arises out of our broader efforts to describe biota - habitat relationships in coastal wetlands, and as such falls under Aquatic Stresso...

  18. Anthropogenic water bodies as drought refuge for aquatic macroinvertebrates and macrophytes.

    PubMed

    Dodemaide, David T; Matthews, Ty G; Iervasi, Dion; Lester, Rebecca E

    2018-03-01

    Ecological research associated with the importance of refuges has tended to focus on natural rather than anthropogenic water bodies. The frequency of disturbances, including drought events, is predicted to increase in many regions worldwide due to human-induced climate change. More frequent disturbance will affect freshwater ecosystems by altering hydrologic regimes, water chemistry, available habitat and assemblage structure. Under this scenario, many aquatic biota are likely to rely on permanent water bodies as refuge, including anthropogenic water bodies. Here, macroinvertebrate and macrophyte assemblages from waste-water treatment and raw-water storages (i.e. untreated potable water) were compared with nearby natural water bodies during autumn and winter 2013. We expected macroinvertebrate and macrophyte assemblages in raw-water storages to be representative of natural water bodies, while waste-water treatment storages would not, due to degraded water quality. However, water quality in natural water bodies differed from raw-water storages but was similar to waste-water treatment storages. Macroinvertebrate patterns matched those of water quality, with no differences occurring between natural water bodies and waste-water treatment storages, but assemblages in raw-water storages differed from the other two water bodies. Unexpectedly, differences associated with raw-water storages were attributable to low abundances of several taxa. Macrophyte assemblages in raw-water storages were representative of natural water bodies, but were less diverse and abundant in, or absent from, waste-water treatment storages. No clear correlations existed between any habitat variables and macroinvertebrate assemblages but a significant correlation between macrophyte assemblages and habitat characteristics existed. Thus, there were similarities in both water quality and macroinvertebrate assemblages between natural water bodies and waste-water treatment storages, and similarities in

  19. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Dolores Project area, southwestern Colorado and southeastern Utah, 1990-91

    USGS Publications Warehouse

    Butler, D.L.; Krueger, R.P.; Osmundson, B.C.; Jensen, E.G.

    1995-01-01

    Water, bottom-sediment, and biota samples were collected in 1990-91 to identify water-quality problems associated with irrigation drainage in the Dolores Project area. Concentrations of cadmium, mercury, and selenium in some water samples exceeded aquatic-life criteria. Selenium was associated with irrigaton drainage from the Dolores Project, but other trace elements may be transported into the area in the irrigation water supply. Selenium concentrations exceeded the chronic aquatic-life criterion in water samples from lower McElmo Creek and Navajo Wash, which drain the Montezuma Valley, from newly irrigated areas, and from the Mancos River. The maximum selenium con- centration in water was 88 micrograms per liter from Navajo Wash. Concentrations of herbicides in water were less than concentrations harmful to aquatic life. Selenium concentrations in four bottom-sediment samples exceeded the baseline concentrations for soils in the Western United States. The largest selenium concentrations in biota were in samples from Navajo Wash, from newly irrigated areas north of the Montezuma Valley, and from the Mancos River basin. Selenium concentrations in aquatic-invertebrate samples from the newly irrigated areas exceeded a guideline for food items consumed by fish and wildlife. Selenium concen- trations in whole-body suckers were larger in the San Juan River downstream from the Dolores Project than upstream from the project at Four Corners. Selenium concentrations in fathead minnow samples from two sites were at adverse-effect levels. Mercury concentrations in warm-water game fish in reservoirs in the study area may be of concern to human health. Some concentrations of other trace elements exceeded background concentrations, but the concentrations were not toxicologically significant or the toxicologic significance is not known.

  20. Use of the white amur for aquatic plant management. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miller, A.C.; Decell, J.L.

    1984-08-01

    The manual presents practical guidelines for the use of the white amur to manage aquatic vegetation in lakes and ponds. This document will introduce the reader to the white amur as a biological control agent for submersed aquatic plants, and present information necessary for successful use of the fish. Included are methods for calculating the number of fish required to effect a desired level of plant control, as well as information on obtaining, shipping, and releasing white amur. Data on feeding, growth rates, food preferences, reproduction, and tolerances to various aquatic conditions are also presented. Case studies on the usemore » of the fish are discussed to illustrate possible impacts of white amur on water chemistry and native biota. While the majority of the information for this report originated in Lake Conway, Florida, the fish is a viable control agent in other parts of the country. This manual should have utility in all parts of the United States in providing background data on the white amur and concise information on the proper use of fish to control submersed aquatic plants. 122 references.« less

  1. Global warming benefits the small in aquatic ecosystems.

    PubMed

    Daufresne, Martin; Lengfellner, Kathrin; Sommer, Ulrich

    2009-08-04

    Understanding the ecological impacts of climate change is a crucial challenge of the twenty-first century. There is a clear lack of general rules regarding the impacts of global warming on biota. Here, we present a metaanalysis of the effect of climate change on body size of ectothermic aquatic organisms (bacteria, phyto- and zooplankton, and fish) from the community to the individual level. Using long-term surveys, experimental data and published results, we show a significant increase in the proportion of small-sized species and young age classes and a decrease in size-at-age. These results are in accordance with the ecological rules dealing with the temperature-size relationships (i.e., Bergmann's rule, James' rule and Temperature-Size Rule). Our study provides evidence that reduced body size is the third universal ecological response to global warming in aquatic systems besides the shift of species ranges toward higher altitudes and latitudes and the seasonal shifts in life cycle events.

  2. Factors Affecting the Distribution of Perfluorinated Compounds in Sediments from Lake Shihwa, Korea

    EPA Science Inventory

    Perfluorinated compounds (PFCs) are ubiquitously distributed in various environmental media including water, soil, sediment, and biota. PFCs have also been shown to biomagnify in both aquatic and terrestrial environments. Lake Shihwa is an artificial saltwater lake, located on ...

  3. The influence of applying additional weight to the affected leg on gait patterns during aquatic treadmill walking in people poststroke.

    PubMed

    Jung, Taeyou; Lee, Dokyeong; Charalambous, Charalambos; Vrongistinos, Konstantinos

    2010-01-01

    Jung T, Lee D, Charalambous C, Vrongistinos K. The influence of applying additional weight to the affected leg on gait patterns during aquatic treadmill walking in people poststroke. To investigate how the application of additional weights to the affected leg influences gait patterns of people poststroke during aquatic treadmill walking. Comparative gait analysis. University-based aquatic therapy center. Community-dwelling volunteers (n=22) with chronic hemiparesis caused by stroke. Not applicable. Spatiotemporal and kinematic gait parameters. The use of an ankle weight showed an increase in the stance phase percentage of gait cycle (3%, P=.015) when compared with no weight. However, the difference was not significant after a Bonferroni adjustment was applied for a more stringent statistical analysis. No significant differences were found in cadence and stride length. The use of an ankle weight showed a significant decrease of the peak hip flexion (7.9%, P=.001) of the affected limb as compared with no weight condition. This decrease was marked as the reduction of unwanted limb flotation because people poststroke typically show excessive hip flexion of the paretic leg in the late swing phase followed by fluctuating hip movements during aquatic treadmill walking. The frontal and transverse plane hip motions did not show any significant differences but displayed a trend of a decrease in the peak hip abduction during the swing phase with additional weights. The use of additional weight did not alter sagittal plane kinematics of the knee and ankle joints. The use of applied weight on the affected limb can reduce unwanted limb flotation on the paretic side during aquatic treadmill walking. It can also assist the stance stability by increasing the stance phase percentage closer to 60% of gait cycle. Both findings can contribute to the development of more efficient motor patterns in gait training for people poststroke. The use of a cuff weight does not seem to reduce the

  4. Steady-state sulfur critical loads and exceedances for protection of aquatic ecosystems in the U.S. southern Appalachian Mountains

    Treesearch

    Todd C. McDonnell; Timothy J. Sullivan; Paul F. Hessburg; Keith M. Reynolds; Nicholas A. Povak; Bernard J. Cosby; William Jackson; R. Brion Salter

    2014-01-01

    Atmospherically deposited sulfur (S) causes stream water acidification throughout the eastern U.S. Southern Appalachian Mountain (SAM) region. Acidification has been linked with reduced fitness and richness of aquatic species and changes to benthic communities. Maintaining acid-base chemistry that supports native biota depends largely on balancing acidic deposition...

  5. Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California.

    PubMed

    Saiki, Michael K; Martin, Barbara A; May, Thomas W

    2012-09-01

    Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98-58.0 μg Se/g; midge larvae, 12.7-50.6 μg Se/g; mosquitofish, 13.2-20.2 μg Se/g; and mollies, 12.8-30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.

  6. Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California

    USGS Publications Warehouse

    Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.

    2012-01-01

    Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98–58.0 μg Se/g; midge larvae, 12.7–50.6 μg Se/g; mosquitofish, 13.2–20.2 μg Se/g; and mollies, 12.8–30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.

  7. Dam removal, connectivity, and aquatic resources in the St. Regis River Watershed, New York

    USGS Publications Warehouse

    McKenna, James E.; Hanak, Kaitlin; DeVilbiss, Katharine; David, Anthony; Johnson, James H.

    2015-10-09

    The decommissioning and planned removal of the Hogansburg Dam on the St. Regis River in New York has stimulated interest in the potential effects of that barrier removal on the St. Regis watershed. There will be immediate and systemic effects of the Hogansburg Dam removal, which may include inundation of habitats below the dam or dewatering of habitats above the dam, possibly affecting local fish assemblages and (or) local native mussel assemblages; and expansion of stream network connectivity, which has the potential to open a large area of the watershed to migratory aquatic species. Information was collected about biota, water quality, sediment distribution, riverbed dimensions in the vicinity of the dam, and habitat characteristics of headwater sample sites. Complete fish assemblages were collected, but species of special concern associated with the connectivity changes included, American Eel, Atlantic Salmon, Brook Trout, Eastern Sand Darter, and Lake Sturgeon. Freshwater mussels in the vicinity of the dam also were examined and may be at risk of exposure (without a rescue plan) after dam removal. Reservoir sediment will be transported downstream and will alter aquatic habitat as it moves through the system. The dam removal will open more than 440 kilometers of stream habitat to migratory species, allowing them to more easily complete their life cycles. Fish assemblages above the dam may be altered by migrating fishes, but resident Brook Trout are not expected to be adversely affected.

  8. Gaps in aquatic toxicological studies of microplastics.

    PubMed

    Karami, Ali

    2017-10-01

    The contamination of aquatic environments with microplastics (MPs) has spurred an unprecedented interest among scientific communities to investigate their impacts on biota. Despite the rapid growth in the number of studies on the aquatic toxicology of MPs, controversy over the fate and biological impacts of MPs is increasingly growing mainly due to the absence of standardized laboratory bioassays. Given the complex features of MPs, such as the diversity of constituent polymers, additives, shapes and sizes, as well as continuous changes in the particle buoyancy as a result of fouling and defouling processes, it is necessary to modify conventional bioassay protocols before employing them for MP toxicity testings. Moreover, several considerations including quantification of chemicals on/in the MP particles, choice of test organisms, approaches for renewing the test solution, aggregation prevention, stock solution preparation, and units used to report MP concentration in the test solution should be taken into account. This critical review suggests some important strategies to help conduct environmentally-relevant MP bioassays. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Baseline levels and trophic transfer of persistent organic pollutants in sediments and biota from the Congo River Basin (DR Congo).

    PubMed

    Verhaert, Vera; Covaci, Adrian; Bouillon, Steven; Abrantes, Katya; Musibono, Dieudonné; Bervoets, Lieven; Verheyen, Erik; Blust, Ronny

    2013-09-01

    The present study aimed to evaluate the occurrence of persistent organic pollutants (POPs: (PCBs, PBDEs, DDTs, HCHs, CHLs and HCB) in sediments and biota from the middle Congo River Basin (CRB) and to investigate their trophic transfer through the aquatic food web using nitrogen stable isotope ratios. To our knowledge, no data on levels of POPs in sediment and biota from the CRB are present in the literature, and studies on trophic transfer and biomagnification profiles of POPs using δ(15)N are scarce in tropical regions. POP levels in the sediment and biota were low, with exception of total PCB levels found in fish from the Itimbiri River (1.4 to 44ng/g ww). Compared to concentrations found in fish from pristine to relatively industrial developed areas, the ∑PCB levels in fish from the Itimbiri were high, indicating the presence of a local PCB contamination source in this catchment. Based on minimum risk level criteria formulated by ATSDR, the consumption of PCB contaminated fish from the Itimbiri river poses a potential risk for humans. The POP levels in biota were not significantly related to the POP levels in sediments, and the BSAF concept (Biota-Sediment Accumulation Factor) was found to be a poor predictor of the bioavailability and bioaccumulation of environmental pollutants in the present study. With increasing trophic levels, a significant increase in PCB 95, 101, 110, 138, 146, 149, 153, 174, 180 & 187 and p,p'-DDT in Itimbiri and BDE 47 & 99 in Itimbiri, Aruwimi & Lomami river basins was observed. Trophic magnification factors were higher than 1, indicating that biomagnification occurs through the tropical food web. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Radiation-induced cytogenetic and hematologic effects on aquatic biota within the Chernobyl exclusion zone.

    PubMed

    Gudkov, D I; Shevtsova, N L; Pomortseva, N A; Dzyubenko, E V; Kaglyan, A E; Nazarov, A B

    2016-01-01

    During 1998-2014 the rate of chromosomal aberrations in embryo tissues of the pond snail (Lymnaea stagnalis) and root meristems of higher aquatic plants, and also hematologic indexes of mantle liquid of the adult snails and peripheral blood of fishes in water bodies within the Chernobyl exclusion zone (EZ) was studied. The absorbed dose rate for hydrobionts from water bodies of the EZ registered in a range from 0.25 to 420 μGy h(-1) and in the reference ones - up to 0.09 μGy h(-1). The level of chromosomal aberrations in the molluscs from the most contaminated water bodies of the EZ was registered within range of 18-27% and for the molluscs from the reference lakes this index was on the average 1.5% with the maximal values 2.3%. The rate of chromosomal aberrations in root meristematic cells of higher aquatic plants from the contaminated lakes of the EZ was in range of 7-17% and in the plants from reference water bodies was not exceed 2.1%. The positive correlation between chromosomal aberration rate and absorbed dose rate in the pond snail's embryos and root meristems of higher aquatic plants in water bodies of the EZ was registered. Analysis of hemolymph structure of snails from the most contaminated water bodies showed a high rate of dead and phagocytic cells as well as decrease of the young amoebocytes quantity. Hematologic research of fish allows to determine on the one hand an insignificant changes of leukogram structure, and from the other hand a high level of red cells with different abnormalities in the peripheral blood of fishes from the water bodies with high levels of radioactive contamination. It is suppose that qualitative indexes of red cells in peripheral blood of fish are more sensitive to long-term radiation impact in comparison with elements of white blood, which can be used for conducting of the hematologic monitoring of radioactive contaminated water bodies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Estimation of Biota Sediment Accumulation Factor (BSAF) from Paired Observations of Chemical Concentrations in Biota and Sediment (Final Report)

    EPA Science Inventory

    In March 2009, EPA's Ecological Risk Assessment Support Center (ERASC) released the final report entitled, Estimation of Biota Sediment Accumulation Factor (BSAF) from Paired Observations of Chemical Concentrations in Biota and Sediment. This report was written in response...

  12. A nationwide survey of perfluorinated alkyl substances in waters, sediment and biota collected from aquatic environment in Vietnam: Distributions and bioconcentration profiles.

    PubMed

    Lam, Nguyen Hoang; Cho, Chon-Rae; Kannan, Kurunthachalam; Cho, Hyeon-Seo

    2017-02-05

    Water, sediment, various tissues of fish, crustacean, gastropod and bivalve were collected from major river basins in Vietnam and analyzed for the presence of perfluorinated alkyl substances (PFASs). Furthermore, the occurrence of PFASs in coastal, tap and well waters collected from eight different regions in Vietnam was investigated. PFOA and PFOS were consistently detected as the dominant PFASs in surface waters. The greatest concentrations of PFOA (53.5ngL -1 ) and PFOS (40.2ngL -1 ) were found in a surface water sample collected from a channel that receives wastewater treatment plant discharges. PFOS and PFHxS were found as the predominant PFASs in sediments. The greatest PFAS concentration in biota was 16.9ng PFUnDA g -1 wet weight found in a fish liver. Some long-chain PFCAs including PFNA, PFUnDA and PFTrDA as well as PFHxS were more abundant than short-chain PFASs in biota tissues. The measured concentrations of PFOS and PFOA in surface and tap waters were below the provisional health advisory. The rank order of mean bioconcentration factor of PFOS in biota was; crustacean (115L/kg), gastropod (1117L/kg), fish (1120L/kg) and bivalve (2110L/kg). This study provides baseline information for a better understanding of PFASs contamination in Vietnam. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Toxicity of anthelmintic drugs (fenbendazole and flubendazole) to aquatic organisms.

    PubMed

    Wagil, Marta; Białk-Bielińska, Anna; Puckowski, Alan; Wychodnik, Katarzyna; Maszkowska, Joanna; Mulkiewicz, Ewa; Kumirska, Jolanta; Stepnowski, Piotr; Stolte, Stefan

    2015-02-01

    Flubendazole (FLU) and fenbendazole (FEN) belong to benzimidazoles-pharmaceuticals widely used in veterinary and human medicine for the treatment of intestinal parasites as well as for the treatment of systemic worm infections. In recent years, usage of these drugs increased, which resulted in a larger contamination of the environment and possible negative effects on biota. Hence, in our research, we investigated an aquatic ecotoxicity of these pharmaceuticals towards: marine bacteria (Vibrio fischeri), green algae (Scenedesmus vacuolatus), duckweed (Lemna minor) and crustacean (Daphnia magna). Ecotoxicity tests were combined with chemical analysis in order to investigate the actual exposure concentration of the compounds used in the experiment as well as to stability and adsorption studies. As a result, study evaluating sensitivity of different aquatic organisms to these compounds and new ecotoxicological data is presented. The strongest negative impact of FLU and FEN was observed to D. magna.

  14. Characterizing Geohydrologic Linkages using Process Domains for Monitoring Aquatic Ecosystems

    NASA Astrophysics Data System (ADS)

    Weekes, A.; Torgersen, C.; Montgomery, D. R.; Woodward, A.; Bolton, S.

    2009-12-01

    Aquatic habitats in glaciated headwater basins can differ widely within a mountain region and are often more complex than those found in lowland river systems. Current legislative mandates for ecosystem monitoring often require the ability to relate geomorphic and hydrologic stream attributes to ecological response. The capacity to define meaningful references states against which to evaluate current status and trends is particularly challenging in mountain aquatic ecosystems. To aid in the implementation of the National Park Service (NPS) Vital Signs Monitoring Program in the mountainous North Coast and Cascades Network (NCCN) parks, this project sought a systematic way to characterize both the spatial distribution of geomorphic controls within the stream hierarchy and to integrate hydrologic response. These controls comprise the physical context that supports biotic “vital signs” in park ecosystems and have consequences that directly affect the life history strategies and persistence of biota living in mountain streams and other aquatic habitats. However, there are currently no monitoring protocols that provide a precedent for incorporating the geomorphic spatial characteristics or diverse types of hydrologic response at the spatial and temporal scales unique to these headwater systems. To address this issue, we investigated relationships between valley-scale glacial macroforms and hydrologic indices (e.g. streamflow gauging, stable isotope analysis and water temperature measurements) in small (1 - 20 km2) headwater basins on the east side of Mount Rainier National Park. The linkage between geomorphic and hydrologic response was found to be best expressed in process domains defined as colluvial, alluvial and bedrock systems. Study results show a correlation between the percentage of colluvial process domains within a headwater catchment and the characteristic hydrologic regime of the basin. These relationships offer a framework that can account for the innate

  15. Effects of land use on the water quality and biota of three streams in the Piedmont province of North Carolina

    USGS Publications Warehouse

    Crawford, J.K.; Lenat, D.R.

    1989-01-01

    Three small streams in North Carolina 's northern Piedmont were studied to compare the effects of land use in their watersheds on water quality characteristics and aquatic biota. Devil 's Cradle Creek (agricultural watershed) had more than two times the sediment yield of Smith Creek (forested watershed) (0.34 tons/acre compared to 0.13 tons/acre), and Marsh Creek (urban watershed) had more than four times the yield of Smith Creek (0.59 tons/acre). Concentrations of nutrients were consistently highest in Devil 's Craddle Creek. Concentrations of total copper, iron, and lead in samples from each of the three streams at times exceeded State water quality standards as did concentrations of total zinc in samples from both Smith and Marsh Creeks. Successively lower aquatic invertebrate taxa richness was found in the forested, the agricultural, and the urban watershed streams. Invertebrate biota in Smith Creek was dominated by insects, such as Ephemeroptera, that are intolerant to stress from pollution, whereas Devil 's Cradle Creek was dominated by the more tolerant Diptera, and Marsh Creek was dominated by the most pollution-tolerant group, the Oligochaeta. Fish communities in the forested and agricultural watershed streams were characterized by more species and more individuals of each species, relative to a limited community in urban Marsh Creek. Three independent variables closely linked to land use--suspended-sediment yield, suspended-sediment load, and total lead concentrations in stream water--are inversely associated with the biological communities of the streams.

  16. Potential risk of acute toxicity induced by AgI cloud seeding on soil and freshwater biota.

    PubMed

    Fajardo, C; Costa, G; Ortiz, L T; Nande, M; Rodríguez-Membibre, M L; Martín, M; Sánchez-Fortún, S

    2016-11-01

    extent, the net photosynthesis (40% inhibition) in both strains of phytoplankton and a moderate decrease in soil bacteria viability. These results suggest that AgI from cloud seeding may moderately affect biota living in both terrestrial and aquatic ecosystems if cloud seeding is repeatedly applied in a specific area and large amounts of seeding materials accumulate in the environment. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Organochlorine compounds in Lake Superior: Chiral polychlorinated biphenyls and biotransformation in the aquatic food web

    USGS Publications Warehouse

    Wong, Charles S.; Mabury, Scott A.; Whittle, D. Michael; Backus, Sean M.; Teixeira, Camilla; DeVault, David S.; Bronte, Charles R.; Muir, Derek C.G.

    2004-01-01

    The enantiomeric composition of seven chiral PCB congeners was measured in the Lake Superior aquatic food web sampled in 1998, to determine the extent of enantioselective biotransformation in aquatic biota. All chiral PCB congeners studied (CBs 91, 95, 136, 149, 174, 176, and 183) biomagnified in the Lake Superior aquatic food web, based on biomagnification and food web magnification factors greater than unity. PCB atropisomers were racemic in phytoplankton and zooplankton, suggesting no biotransformation potential toward PCBs for these low trophic level organisms. However, Diporeia and mysids had significantly nonracemic residues for most chiral congeners studied. This observation suggests that these macrozooplankton can stereoselectively metabolize chiral congeners. Alternatively, macrozooplankton obtained nonracemic residues from feeding on organic-rich suspended particles and sediments, which would imply that stereoselective microbial PCB biotransformation may be occurring in Lake Superior sediments at PCB concentrations far lower than that previously associated with such activity. Widely nonracemic PCB residues in forage fish (lake herring, rainbow smelt, and slimy sculpin) and lake trout suggest a combination of both in vivo biotransformation and uptake of nonracemic residues from prey for these species. Minimum biotransformation rates, calculated from enantiomer mass balances between predators and prey, suggest metabolic half-lives on the order of 8 yr for CB 136 in lake trout and 2.6 yr for CB 95 in sculpins. This result suggests that significant biotransformation may occur for metaboliz able PCB congeners over the lifespan of these biota. This study highlights the potential of chiral analysis to study biotransformation processes in food webs.

  18. Marine Biota and Psychological Well-Being

    PubMed Central

    Cracknell, Deborah; White, Mathew P.; Pahl, Sabine; Nichols, Wallace J.; Depledge, Michael H.

    2015-01-01

    Exposure to natural environments can have calming and stress-reducing effects on humans. Moreover, previous studies suggest that these benefits may be greater in areas with higher species richness. Our study took advantage of a “natural experiment” to examine people’s behavioral, physiological, and psychological reactions to increases in levels of marine biota in a large aquarium exhibit during three stages of restocking: Unstocked, Partially stocked, and Fully stocked. We found that increased biota levels were associated with longer spontaneous viewing of the exhibit, greater reductions in heart rate, greater increases in self-reported mood, and higher interest. We suggest that higher biota levels, even in managed settings, may be associated with important well-being and health benefits, particularly for individuals not able to access the natural analogues of managed environments. PMID:27818525

  19. Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound.

    PubMed

    Lee, Timothy S; Toft, Jason D; Cordell, Jeffery R; Dethier, Megan N; Adams, Jeffrey W; Kelly, Ryan P

    2018-01-01

    Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic-terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness) from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable.

  20. Effects of ashes from a Brazilian savanna wildfire on water, soil and biota: An ecotoxicological approach.

    PubMed

    Oliveira-Filho, Eduardo C; Brito, Darlan Q; Dias, Zelia M B; Guarieiro, Mayara S; Carvalho, Esther L; Fascineli, Maria L; Niva, Cintia C; Grisolia, Cesar K

    2018-03-15

    Wildfire is very common in Brazilian savannas, and its effects on water, soil and aquatic/soil organisms are poorly understood. In this study, we observed the effects of fire, especially of ashes, on surface soil and subsurface water in a typical Brazilian savanna (Cerrado sensu strictu) for one year. Soil analyses (pH, organic matter content, potential acidity, K, Ca, Mg and P) and subsurface water analyses (NO 3- , PO 4 3- Mg 2+ , Ca 2+ and K + ) were assessed. We evaluated the ecotoxicological effects of ashes on three different endpoints and species, in fish Danio rerio (embryonic development), aquatic snail Biomphalaria glabrata (reproduction) and a soil species Enchytraeus sp. (reproduction). We found a higher amount of exchangeable cations and organic matter content in short-term fire effects on soil, but the higher availability of nutrients did not affect the soil pH in field plots. The effects of ashes on soil and subsurface water did not persist for one-year post-fire, except for organic matter content in burned areas. No toxic effects were observed on hatching success and incidences of developmental abnormalities in D. rerio embryos. However, ash input had adverse effects on reproduction in snails and enchytraeids. We reported a statistically significant decrease in snail eggs exposed to the 50g.L -1 and 100g.L -1 of ashes after four weeks (p<0.05, Dunnett's test and Tukey test). Enchytraeus sp. reproduction was negatively influenced by the natural soil, which presents high acidity, and also when exposed directly to the ashes from burned area, suggesting that pH and other ash compounds may limit the growth of enchytraeids. More studies in burned areas are strongly encouraged, addressing the potential important routes of exposure to ashes in order to understand the impact of intense fires on soil and aquatic biota in tropical savannas. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Aquatic insect assemblages associated with subalpine stream segment types in relict glaciated headwaters

    USGS Publications Warehouse

    Kubo, Joshua S.; Torgersen, Christian E.; Bolton, Susan M.; Weekes, Anne A.; Gara, Robert I.

    2013-01-01

    1. Aquatic habitats and biotic assemblages in subalpine headwaters are sensitive to climate and human impacts. Understanding biotic responses to such perturbations and the contribution of high-elevation headwaters to riverine biodiversity requires the assessment of assemblage composition among habitat types. We compared aquatic insect assemblages among headwater stream segment types in relict glaciated subalpine basins in Mt. Rainier National Park, Washington, USA. 2. Aquatic insects were collected during summer and autumn in three headwater basins. In each basin, three different stream segment types were sampled: colluvial groundwater sources, alluvial lake inlets, and cascade-bedrock lake outlets. Ward's hierarchical cluster analysis revealed high β diversity in aquatic insect assemblages, and non-metric multidimensional scaling indicated that spatial and temporal patterns in assemblage composition differed among headwater stream segment types. Aquatic insect assemblages showed more fidelity to stream segment types than to individual basins, and the principal environmental variables associated with assemblage structure were temperature and substrate. 3. Indicator species analyses identified specific aquatic insects associated with each stream segment type. Several rare and potentially endemic aquatic insect taxa were present, including the recently described species, Lednia borealis (Baumann and Kondratieff). 4. Our results indicate that aquatic insect assemblages in relict glaciated subalpine headwaters were strongly differentiated among stream segment types. These results illustrate the contribution of headwaters to riverine biodiversity and emphasise the importance of these habitats for monitoring biotic responses to climate change. Monitoring biotic assemblages in high-elevation headwaters is needed to prevent the potential loss of unique and sensitive biota.

  2. Ecotoxicological assessments show sucralose and fluoxetine affect the aquatic plant, Lemna minor.

    PubMed

    Amy-Sagers, Cherisse; Reinhardt, Keith; Larson, Danelle M

    2017-04-01

    Pharmaceuticals and personal care products (PPCP) are prevalent in aquatic systems, yet the fate and impacts on aquatic plants needs quantification for many compounds. We measured and detected sucralose (an artificial sweetener), fluoxetine (an antidepressant), and other PPCP in the Portneuf River in Idaho, USA, where Lemna minor (an aquatic plant in the environment and used in ecotoxicology studies) naturally occurs. Sucralose was hypothesized to negatively affect photosynthesis and growth of L. minor because sucralose is a chlorinated molecule that may be toxic or unusable for plant metabolism. A priori hypotheses were not created for fluoxetine due to lack of previous studies examining its impacts on plants. We conducted laboratory ecotoxicological assessments for a large range of concentrations of sucralose and fluoxetine on L. minor physiology and photosynthetic function. Frond green leaf area, root length, growth rate, photosynthetic capacity, and plant carbon isotopic composition (discrimination relative to a standard; δ 13 C) were measured among treatments ranging from 0 to 15000nmol/L-sucralose and 0-323nmol/L-fluoxetine. Contrary to our predictions, sucralose significantly increased green leaf area, photosynthetic capacity, and δ 13 C of L. minor at environmentally relevant concentrations. The increase of δ 13 C from sucralose amendments and an isotope-mixing model indicated substantial sucralose uptake and assimilation within the plant. Unlike humans who cannot break down and utilize sucralose, we documented that L. minor-a mixotrophic plant-can use sucralose as a sugar substitute to increase its green leaf area and photosynthetic capacity. Fluoxetine significantly decreased L. minor root growth, daily growth rate, and asexual reproduction at 323nmol/L-fluoxetine; however, ambiguity remains regarding the mechanisms responsible and the applicability of these extreme concentrations unprecedented in the natural environment. To our knowledge, this was the

  3. Critical role of seasonal tributaries for native fish and aquatic biota in the Sacramento River

    NASA Astrophysics Data System (ADS)

    Marchetti, M.

    2016-12-01

    We examined the ecology of seasonal tributaries in California in terms of native fishes and aquatic macroinvertebrates. This talk summarizes data from five individual studies. Studying juvenile Chinook growth using otolith microstructure we find that fish grow faster and larger in seasonal tributaries. In a four-year study on the abundance of native fish larvae in tributaries of the Sacramento River we find certain tributaries produce an order of magnitude more native fish larvae than nearby permanent streams. In a study comparing the distribution and abundance of aquatic macroinvertebrates in a seasonal tributary with a permanent stream we find the seasonal tributary contains unique taxa, higher drift densities and ecologically distinct communities. In a cross-watershed comparison of larval fish drift we find that a seasonal tributary produces more larvae than all other streams/rivers we examined. In a comparison of juvenile Chinook growth morphology between seasonal and permanent streams using geometric morphometrics we find that salmon show phenotypic plasticity and their growth is characteristically different in seasonal tributaries. Taken together, this body of work highlights the critical ecological importance of this habitat.

  4. Irrigation-induced contamination of water, sediment, and biota in the western United States-synthesis of data from the National Irrigation Water Quality Program

    USGS Publications Warehouse

    Seiler, Ralph L.; Skorupa, Joseph P.; Naftz, David L.; Nolan, B. Thomas

    2003-01-01

    In October 1985 the U.S. Department of the Interior (DOI), through the National Irrigation Water Quality Program (NIWQP), began a series of field investigations at 26 areas in the Western United States to determine whether irrigation drainage has had harmful effects on fish, wildlife, and humans or has reduced beneficial uses of water. In 1992 NIWQP initiated the Data Synthesis Project to evaluate data collected during the field investigations. Geologic, climatologic, and hydrologic data were evaluated and water, sediment, and biota from the 26 areas were analyzed to identify commonalities and dominant factors that result in irrigation-induced contamination of water and biota. Data collected for the 26 area investigations have been compiled and merged into a common data base. The structure of the data base is designed to enable assessment of relations between contaminant concentrations in water, sediment, and biota. The data base is available to the scientific community through the World Wide Web at URL http://www.usbr.gov/niwqp. Analysis of the data base for the Data Synthesis included use of summary statistics, factor analysis, and logistic regression. A Geographic Information System was used to store and analyze spatially oriented digital data such as land use, geology and evaporation rates. In the U.S. Department of the Interior (DOI) study areas, samples of water, bottom sediment, and biota were collected for trace-element and pesticide analysis. Contaminants most commonly associated with irrigation drainage were identified by comparing concentrations in water with established criteria. For surface water, the criteria used were typically chronic criteria for the protection of freshwater aquatic life. Because ground water can discharge to the surface where wildlife can be exposed to it, the criteria used for ground water were both the maximum contaminant levels (MCL's) for drinking water and the chronic criteria for the protection of freshwater aquatic life

  5. Plant Diversity Surpasses Plant Functional Groups and Plant Productivity as Driver of Soil Biota in the Long Term

    PubMed Central

    Eisenhauer, Nico; Milcu, Alexandru; Sabais, Alexander C. W.; Bessler, Holger; Brenner, Johanna; Engels, Christof; Klarner, Bernhard; Maraun, Mark; Partsch, Stephan; Roscher, Christiane; Schonert, Felix; Temperton, Vicky M.; Thomisch, Karolin; Weigelt, Alexandra; Weisser, Wolfgang W.; Scheu, Stefan

    2011-01-01

    Background One of the most significant consequences of contemporary global change is the rapid decline of biodiversity in many ecosystems. Knowledge of the consequences of biodiversity loss in terrestrial ecosystems is largely restricted to single ecosystem functions. Impacts of key plant functional groups on soil biota are considered to be more important than those of plant diversity; however, current knowledge mainly relies on short-term experiments. Methodology/Principal Findings We studied changes in the impacts of plant diversity and presence of key functional groups on soil biota by investigating the performance of soil microorganisms and soil fauna two, four and six years after the establishment of model grasslands. The results indicate that temporal changes of plant community effects depend on the trophic affiliation of soil animals: plant diversity effects on decomposers only occurred after six years, changed little in herbivores, but occurred in predators after two years. The results suggest that plant diversity, in terms of species and functional group richness, is the most important plant community property affecting soil biota, exceeding the relevance of plant above- and belowground productivity and the presence of key plant functional groups, i.e. grasses and legumes, with the relevance of the latter decreasing in time. Conclusions/Significance Plant diversity effects on biota are not only due to the presence of key plant functional groups or plant productivity highlighting the importance of diverse and high-quality plant derived resources, and supporting the validity of the singular hypothesis for soil biota. Our results demonstrate that in the long term plant diversity essentially drives the performance of soil biota questioning the paradigm that belowground communities are not affected by plant diversity and reinforcing the importance of biodiversity for ecosystem functioning. PMID:21249208

  6. Occurrence of antibiotics in water, sediments, aquatic plants, and animals from Baiyangdian Lake in North China.

    PubMed

    Li, Wenhui; Shi, Yali; Gao, Lihong; Liu, Jiemin; Cai, Yaqi

    2012-11-01

    This study investigated the presence and distribution of 22 antibiotics, including eight quinolones, nine sulfonamides and five macrolides, in the water, sediments, and biota samples from Baiyangdian Lake, China. A total of 132 samples were collected in 2008 and 2010, and laboratory analyses revealed that antibiotics were widely distributed in the lake. Sulfonamides were the dominant antibiotics in the water (0.86-1563 ng L(-1)), while quinolones were prominent in sediments (65.5-1166 μg kg(-1)) and aquatic plants (8.37-6532 μg kg(-1)). Quinolones (17.8-167 μg kg(-1)) and macrolides [from below detection limit (BDL) to 182 μg kg(-1)] were often found in aquatic animals and birds. Salvinia natans exhibited the highest bioaccumulation capability for quinolones among three species of aquatic plants. Geographical differences of antibiotic concentrations were greatly due to anthropogenic activities. Sewage discharged from Baoding City was likely the main source of antibiotics in the lake. Risk assessment of antibiotics on aquatic organisms suggested that algae and aquatic plants might be at risk in surface water, while animals were likely not at risk. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Assessment of dose rate to terrestrial biota in the area around coal fired power plant applying ERICA tool and RESRAD BIOTA code.

    PubMed

    Ćujić, Mirjana; Dragović, Snežana

    2018-08-01

    This paper presents the environmental radiation risk assessment based on two software program approaches ERICA Tool (version 1.2) and RESRAD BIOTA (version 1.5) to estimate dose rates to terrestrial biota in the area around the largest coal fired power plant in Serbia. For dose rate assessment software's default reference animals and plants and the best estimated values of activity concentrations of 238 U, 234 U, 234 Th, 232 Th, 230 Th, 226 Ra, 210 Pb, 210 Po, 137 Cs in soil were used. Both approaches revealed the highest contribution to the internal dose rate due to 226 Ra and 210 Po, while 137 Cs contributed the most to the external dose rate. In the investigated area total dose rate to biota derived using ERICA Tool ranged from 0.3 to 14.4 μGy h -1 . The natural radionuclides exhibited significantly higher contribution to the total dose rate than the artificial one. In the investigated area, only dose rate for lichens and bryophytes exceeded ERICA Tool screening value of total dose rate of 10 μGy h -1 suggested as confident that environmental risks are negligible. The assessed total dose rates for reference animals and plants using RESRAD BIOTA were found to be 7 and 3 μGy h -1 , respectively. In RESRAD BIOTA - Level 3, 10 species (Lumbricus terrestris, Rana lessonae, Sciurus vulgaris, Anas platyrhynchos, Lepus europaeus, Vulpes vulpes, Capreolus capreolus, Suss crofa, Quercu srobur, Tilia spp.) representative for the study area were modeled. Among them the highest total dose rate (4.5 μGy h -1 ) was obtained for large mammals. Differences in the predicted dose rates to biota using the two software programs are the consequence of the difference in the values of transfer parameters used to calculate activity concentrations in biota. Doses of ionizing radiation estimated in this study will not exhibit deterministic effects at the population level. Thus, the obtained results indicate no significant radiation impact of coal fired power plant operation on

  8. Isolation of microplastics in biota-rich seawater samples and marine organisms

    NASA Astrophysics Data System (ADS)

    Cole, Matthew; Webb, Hannah; Lindeque, Pennie K.; Fileman, Elaine S.; Halsband, Claudia; Galloway, Tamara S.

    2014-03-01

    Microplastic litter is a pervasive pollutant present in aquatic systems across the globe. A range of marine organisms have the capacity to ingest microplastics, resulting in adverse health effects. Developing methods to accurately quantify microplastics in productive marine waters, and those internalized by marine organisms, is of growing importance. Here we investigate the efficacy of using acid, alkaline and enzymatic digestion techniques in mineralizing biological material from marine surface trawls to reveal any microplastics present. Our optimized enzymatic protocol can digest >97% (by weight) of the material present in plankton-rich seawater samples without destroying any microplastic debris present. In applying the method to replicate marine samples from the western English Channel, we identified 0.27 microplastics m-3. The protocol was further used to extract microplastics ingested by marine zooplankton under laboratory conditions. Our findings illustrate that enzymatic digestion can aid the detection of microplastic debris within seawater samples and marine biota.

  9. Isolation of microplastics in biota-rich seawater samples and marine organisms

    PubMed Central

    Cole, Matthew; Webb, Hannah; Lindeque, Pennie K.; Fileman, Elaine S.; Halsband, Claudia; Galloway, Tamara S.

    2014-01-01

    Microplastic litter is a pervasive pollutant present in aquatic systems across the globe. A range of marine organisms have the capacity to ingest microplastics, resulting in adverse health effects. Developing methods to accurately quantify microplastics in productive marine waters, and those internalized by marine organisms, is of growing importance. Here we investigate the efficacy of using acid, alkaline and enzymatic digestion techniques in mineralizing biological material from marine surface trawls to reveal any microplastics present. Our optimized enzymatic protocol can digest >97% (by weight) of the material present in plankton-rich seawater samples without destroying any microplastic debris present. In applying the method to replicate marine samples from the western English Channel, we identified 0.27 microplastics m−3. The protocol was further used to extract microplastics ingested by marine zooplankton under laboratory conditions. Our findings illustrate that enzymatic digestion can aid the detection of microplastic debris within seawater samples and marine biota. PMID:24681661

  10. A novel approach to analysing the regimes of temporary streams in relation to their controls on the composition and structure of aquatic biota

    NASA Astrophysics Data System (ADS)

    Gallart, F.; Prat, N.; García-Roger, E. M.; Latron, J.; Rieradevall, M.; Llorens, P.; Barberá, G. G.; Brito, D.; De Girolamo, A. M.; Lo Porto, A.; Buffagni, A.; Erba, S.; Neves, R.; Nikolaidis, N. P.; Perrin, J. L.; Querner, E. P.; Quiñonero, J. M.; Tournoud, M. G.; Tzoraki, O.; Skoulikidis, N.; Gómez, R.; Sánchez-Montoya, M. M.; Froebrich, J.

    2012-09-01

    Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The structure and composition of biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. Therefore, the structural and functional characteristics of aquatic fauna to assess the ecological quality of a temporary stream reach cannot be used without taking into account the controls imposed by the hydrological regime. This paper develops methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the transient sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: Hyperrheic, Eurheic, Oligorheic, Arheic, Hyporheic and Edaphic. When the hydrological conditions lead to a change in the aquatic state, the structure and composition of the aquatic community changes according to the new set of available habitats. We used the water discharge records from gauging stations or simulations with rainfall-runoff models to infer the temporal patterns of occurrence of these states in the Aquatic States Frequency Graph we developed. The visual analysis of this graph is complemented by the development of two metrics which describe the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of temporary streams in four aquatic regimes in terms of their influence over the development of aquatic life is updated from the existing classifications, with stream aquatic regimes defined as Permanent, Temporary-pools, Temporary-dry and Episodic. While aquatic regimes describe the long-term overall variability of the hydrological conditions of the river section and have been used for many years by hydrologists and ecologists, aquatic states describe the availability of mesohabitats in given periods that

  11. Deployment Area Selection and Land Withdrawal/Acquisition. M-X/MPS (M-X/Multiple Protective Shelter) Environmental Technical Report. Aquatic Habitats and Biota.

    DTIC Science & Technology

    1981-10-02

    section of resident and nonresident sportsmen. Aquatic habitats provide water and forage for terrestrial wildlife, particularly birds and the larger...swimming, camping, and picnicking areas. Bird and wildlife observation in the study area is usually best near aquatic habitats. Since surface waters are...inundated by surface or groundwater with a frequency sufficient to support a prevalence of vegetative or aquatic life that requires saturated or seasonally

  12. Soil biota can change after exotic plant invasion: Does this affect ecosystem processes?

    USGS Publications Warehouse

    Belnap, J.; Phillips, S.L.; Sherrod, S.K.; Moldenke, A.

    2005-01-01

    Invasion of the exotic annual grass Bromus tectorum into stands of the native perennial grass Hilaria jamesii significantly reduced the abundance of soil biota, especially microarthropods and nematodes. Effects of invasion on active and total bacterial and fungal biomass were variable, although populations generally increased after 50+ years of invasion. The invasion of Bromus also resulted in a decrease in richness and a species shift in plants, microarthropods, fungi, and nematodes. However, despite the depauperate soil fauna at the invaded sites, no effects were seen on cellulose decomposition rates, nitrogen mineralization rates, or vascular plant growth. When Hilaria was planted into soils from not-invaded, recently invaded, and historically invaded sites (all currently or once dominated by Hilaria), germination and survivorship were not affected. In contrast, aboveground Hilaria biomass was significantly greater in recently invaded soils than in the other two soils. We attributed the Hilaria response to differences in soil nutrients present before the invasion, especially soil nitrogen, phosphorus, and potassium, as these nutrients were elevated in the soils that produced the greatest Hilaria biomass. Our data suggest that it is not soil biotic richness per se that determines soil process rates or plant productivity, but instead that either (1) the presence of a few critical soil food web taxa can keep ecosystem function high, (2) nutrient loss is very slow in this ecosystem, and/or (3) these processes are microbially driven. However, the presence of Bromus may reduce key soil nutrients over time and thus may eventually suppress native plant success. ?? 2005 by the Ecological Society of America.

  13. Ecosystem services of soil biota: In what context is a focus on soil biota meaningful?

    NASA Astrophysics Data System (ADS)

    Baveye, Philippe C.

    2016-04-01

    Over the last few years, the topic of the ecosystem services of soils has attracted considerable attention, in particular among researchers working on soil biota. A direct link is established explicitly in numerous articles between soil biota and specific ecosystem services, or between soil biodiversity and ecosystem services. A careful review of the literature indicates however that these links are, more often than not, strictly axiomatic, rather than based on actual observations. In fact, there are still at the moment virtually no measurements of ecosystem services of soils at any scale, measurements that would be required to establish such links. Furthermore, at a conceptual level, it is not clear to what extent the effect of soil biota in the delivery of ecosystem services can be separated from the contribution of other components of soil systems. Soil microorganisms, in particular, proliferate and are metabolically active in a pore space whose characteristics and dynamics could in principle have a profound effect on their activity. So also could the composition and spatial distribution of soil organic matter, or the spatial pattern of plant root propagation. By emphasizing the role of soil biota, at the exclusion of other aspects of soil systems, there is a risk that important features of the provision of ecosystem services by soils will be missed. In this talk (based in part on a workshop organized recently in France, and of a follow-up review article), an analysis of this general problem will be presented, as well as suggestions of how to avoid it by promoting truly interdisciplinary research involving not only soil ecologists but also physicists, hydrologists, and chemists.

  14. EPA ’s ECOLOGICAL MODELS FOR INTEGRATED WATERSHED MANAGEMENT

    EPA Science Inventory

    Aquatic ecological populations and communities are affected by the nature and quality of the water in which they live. Specific factors that affect instream biota include chemical variables, biotic interactions, energy source, flow regime, and habitat structure. As watershed mana...

  15. Detailed study of selenium in soil, water, bottom sediment, and biota in the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge, west-central Montana, 1990-92

    USGS Publications Warehouse

    Nimick, D.A.; Lambing, J.H.; Palawski, D.U.; Malloy, J.C.

    1996-01-01

    Selenium and other constituents are adversely affecting water quality and creating a potential hazard to wildlife in several areas of the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge in west-central Montana. Selenium derived from Cretaceous shale and Tertiary and Quaternary deposits containing shale detritus is transported in the oxic shallow ground-water systems. At Freezout Lake Wildlife Management Area, drainage from irrigated glacial deposits is the primary source of selenium; drainage from non-irrigated farmland is a significant source locally. Benton Lake generally receives more selenium from natural runoff from its non-irrigated basin than from the trans-basin diversion of irrigation return flow. Selenium has accumulated in aquatic plants and invertebrates, fish, and water birds, particularly in wetlands that receive the largest selenium loads. Although selenium residues in biological tissue from some wetland units exceeded biological risk levels, water-bird reproduction generally has not been impaired. The highest selenium residues in biota commonly occurred in samples from Priest Butte Lakes, which also had the highest selenium concentration in wetland water. Selenium concentrations in all invertebrate samples from Priest Butte Lakes and the south end of Freezeout Lake exceeded the critical dietary threshold for water birds. Selenium delivered to wetlands accumulates in bottom sediment, predominantly in near-shore areas. Potential impacts to water quality, and presumably biota, may be greatest near the mouths of inflows. Most selenium delivered to wetlands will continue to accumulate in bottom sediment and biota.

  16. Detailed study of irrigation drainage in and near wildlife management areas, west-central Nevada, 1987-90; Part C, Summary of irrigation-drainage effects on water quality, bottom sediment, and biota

    USGS Publications Warehouse

    Hoffman, Ray J.

    1993-01-01

    This report presents a summary of the detailed scientific study of Stillwater Wildlife Management Area and other nearby wetlands in west-central Nevada during 1987-90. The work was funded by the National Irrigation Water Quality Program of the U.S. Department of the Interior with the overall objectives of determining (1) the extent, magnitude, and effects of selected water-quality constituents associated with irrigation drainage on fish, wildlife, and human health, and (2) the sources and exposure pathways that cause contamination where adverse effects are documented. Much of the information in this report was summarized from two previously published interpretive reports that were completed to fulfill study objectives. Where applicable, data for the study area from other published sources also were utilized. The results of these studies indicate that the aquatic biota in natural wetlands of the Carson Desert are adversely affected by hydrological and geochemical sources and processes in the Newlands Irrigation Project area. Reactions between water and naturally occurring minerals in the shallow alluvial aquifer increase concentrations of potentially toxic constituents in ground water that eventually enters the wetlands. Once in the wetlands, these constituents are furhter concentrated by evaporation and transpiration. Water from some agricultural drains that enter Stillwater WMA was acutely toxic to aquatic organisms. The drains in the agricultural areas, which eventually discharge to the wetlands, were also implicated as sites of uptake of selenium and mercury by aquatic organisms.

  17. Off-site impacts of wildfires on aquatic systems - Biomarker responses of the mosquitofish Gambusia holbrooki.

    PubMed

    Nunes, Bruno; Silva, Vera; Campos, Isabel; Pereira, Joana Luísa; Pereira, Patrícia; Keizer, Jan Jacob; Gonçalves, Fernando; Abrantes, Nelson

    2017-03-01

    The number of wildfires has markedly increased in Mediterranean Europe, including in Portugal. Wildfires are environmentally concerning, not only due to the loss of biodiversity and forest area, but also as a consequence of environmental contamination by specific compounds including metals and polycyclic aromatic compounds (PAHs). These contaminants, mostly bound to ashes, can reach downstream water bodies, namely through surface runoff, being ultimately dispersed by vast areas and contacting with aquatic biota. Being toxicologically noteworthy, the potential toxic outcomes of the input of such chemicals across the aquatic compartment must be characterized. In this context, the present study used a biomarker-based approach to find early-warning signals of toxicity triggered by the exposure of the mosquitofish, Gambusia holbrooki, to affected aqueous runoff and stream water samples collected from a forest burnt area. The chemical analysis revealed concerning levels of metals and polycyclic aromatic hydrocarbons in both runoff and stream water samples. Biological responses elicited by the collected samples showed the occurrence of pro-oxidative modifications, specifically driven by enzymatic forms involved in the metabolism of glutathione. Despite these effects, no further signs of involvement of metals and PAHs were elicited in terms of neurotoxicity. The overall set of data implicates chemicals resulting from wildfires in clear deleterious effects in exposed fish. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Method for the determination of organophosphate insecticides in water, sediment and biota.

    PubMed

    Tse, Hung; Comba, Michael; Alaee, Mehran

    2004-01-01

    A procedure for the determination of 13 organophosphate insecticides (OPs) in water, sediment and biota at low ppb levels is described. Samples were extracted with dichloromethane or acetone/hexane and cleaned up with micro-column silica gel chromatography. Measurements were made by dual capillary column gas chromatography using both nitrogen-phosphorus (NPD) and electron capture (ECD) detection. Recoveries from fortified water samples ranged from 76% to 102% for all sample types. Practical detection limits ranged between 0.003 and 0.029 microg/l in natural water samples, 0.0004-0.005 microg/g w.w. for sediments, and 0.001-0.005 microg/g w.w for biota using the NPD and ECD method. Losses in sediments were experienced when sulphur was removed. Precision and accuracy were not affected in sediment samples where sulphur was not removed.

  19. Assessing off-site impacts of wildfires on aquatic organisms using in-situ assays

    NASA Astrophysics Data System (ADS)

    Ré, Ana; Saraiva, MariaJoão; Puga, João; Campos, Isabel; Pereira, Joana; Keizer, Jacob; Goncalves, Fernando; Abrantes, Nelson

    2017-04-01

    Wildfires have been recognized as an important source of diffuse pollution to aquatic systems, particularly through the production and transport of pyrolytic substances such as polycyclic aromatic hydrocarbons (PAHs) and metals associated to ash/soil loads. However, the effects of these compounds from recently burnt areas on the aquatic biota have been largely ignored. Hence, the main goal of this study was to assess the ecotoxicological effects of wildfires in aquatic systems through the use of in situ experiments. In this sense, five sites were selected in a catchment partially burnt: two in the main water course - Ceira river (Miranda do Corvo, Portugal), being one located upstream (RUS) and the other downstream (RDS) the burnt area; two in tributary streams within the burnt area (SUS and SDS); and finally one in a stream located in the unburnt part of the catchment (CS). During the first post-fire rainfall events, distinct organisms, including the water flea Daphnia magna, the freshwater shrimp Atyaephyra desmaresti, the freshwater clam Corbicula fluminea and the mosquitofish Gambusia holbrooki were exposed in situ, in all five sites, using dedicated test chambers. After four days of field exposition, the mortality and post-exposure feeding inhibition were evaluated. Feeding depression after exposure time was selected as a sub-lethal endpoint because it is a quick, sensitive and ecologically relevant indicator of toxic stress. The results showed negligible mortality for all the species and sites, thus lethality was not sensitive to discern impacts among the assessed sites. Conversely, the sub-lethal post-exposure feeding inhibition endpoint, revealed a decrease of feeding rate, in streams within the burnt area (SUS and SDS), that seemed to be the most affected places in the study area. Conversely, the sites outside the burnt area, both on river (RUS) and on the stream (CS), showed no adverse effects in this endpoint. Hence, the current results pointed-out that

  20. Competing risks and the development of adaptive management plans for water resources: Field reconnaissance investigation of risks to fishes and other aquatic biota exposed to endocrine disrupting chemicals (edcs) in lake mead, Nevada USA

    USGS Publications Warehouse

    Linder, G.; Little, E.E.

    2009-01-01

    The analysis and characterization of competing risks for water resources rely on a wide spectrum of tools to evaluate hazards and risks associated with their management. For example, waters of the lower Colorado River stored in reservoirs such as Lake Mead present a wide range of competing risks related to water quantity and water quality. These risks are often interdependent and complicated by competing uses of source waters for sustaining biological resources and for supporting a range of agricultural, municipal, recreational, and industrial uses. USGS is currently conducting a series of interdisciplinary case-studies on water quality of Lake Mead and its source waters. In this case-study we examine selected constituents potentially entering the Lake Mead system, particularly endocrine disrupting chemicals (EDCs). Worldwide, a number of environmental EDCs have been identified that affect reproduction, development, and adaptive behaviors in a wide range of organisms. Many EDCs are minimally affected by current treatment technologies and occur in treated sewage effluents. Several EDCs have been detected in Lake Mead, and several substances have been identified that are of concern because of potential impacts to the aquatic biota, including the sport fishery of Lake Mead and endangered razorback suckers (Xyrauchen texanus) that occur in the Colorado River system. For example, altered biomarkers relevant to reproduction and thyroid function in fishes have been observed and may be predictive of impaired metabolism and development. Few studies, however, have addressed whether such EDC-induced responses observed in the field have an ecologically significant effect on the reproductive success of fishes. To identify potential linkages between EDCs and species of management concern, the risk analysis and characterization in this reconnaissance study focused on effects (and attendant uncertainties) that might be expressed by exposed populations. In addition, risk reduction

  1. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River site

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Friday, G.P.; Cummins, C.L.; Schwartzman, A.L.

    Since the early 1950s, the Savannah River Site (SRS) released over 50 radionuclides into the environment while producing nuclear defense materials. These releases directly exposed aquatic and terrestrial biota to ionizing radiation from surface water, soil, and sediment, and also indirectly by the ingestion of items in the food chain. As part of new missions to develop waste management strategies and identify cost-effective environmental restoration options, knowledge concerning the uptake and distribution of these radionuclides is essential. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at SRS.

  2. AQUATIC PLANT SPECIATION AFFECTED BY DIVERSIFYING SELECTION OF ORGANELLE DNA REGIONS(1).

    PubMed

    Kato, Syou; Misawa, Kazuharu; Takahashi, Fumio; Sakayama, Hidetoshi; Sano, Satomi; Kosuge, Keiko; Kasai, Fumie; Watanabe, Makoto M; Tanaka, Jiro; Nozaki, Hisayoshi

    2011-10-01

    Many of the genes that control photosynthesis are carried in the chloroplast. These genes differ among species. However, evidence has yet to be reported revealing the involvement of organelle genes in the initial stages of plant speciation. To elucidate the molecular basis of aquatic plant speciation, we focused on the unique plant species Chara braunii C. C. Gmel. that inhabits both shallow and deep freshwater habitats and exhibits habitat-based dimorphism of chloroplast DNA (cpDNA). Here, we examined the "shallow" and "deep" subpopulations of C. braunii using two nuclear DNA (nDNA) markers and cpDNA. Genetic differentiation between the two subpopulations was measured in both nDNA and cpDNA regions, although phylogenetic analyses suggested nuclear gene flow between subpopulations. Neutrality tests based on Tajima's D demonstrated diversifying selection acting on organelle DNA regions. Furthermore, both "shallow" and "deep" haplotypes of cpDNA detected in cultures originating from bottom soils of three deep environments suggested that migration of oospores (dormant zygotes) between the two habitats occurs irrespective of the complete habitat-based dimorphism of cpDNA from field-collected vegetative thalli. Therefore, the two subpopulations are highly selected by their different aquatic habitats and show prezygotic isolation, which represents an initial process of speciation affected by ecologically based divergent selection of organelle genes. © 2011 Phycological Society of America.

  3. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Pine River Project area, Southern Ute Indian Reservation, southwestern Colorado and northwestern New Mexico, 1988-89

    USGS Publications Warehouse

    Butler, D.L.; Krueger, R.P.; Osmundson, B.C.; Thompson, A.L.; Formea, J.J.; Wickman, D.W.

    1993-01-01

    During 1988-89, water, bottom sediment, biota, soil, and plants were sampled for a reconnaissance investigation of the Pine River Project area in southwestern Colorado. Irrigation drainage does not seem to be a major source of dissolved solids in streams. Concentrations of manganese, mercury, and selenium exceeded drinking-water regulations in some streams. The maximum selenium concentration in a stream sample was 94 microg/L in Rock Creek. Irrigation drainage and natural groundwater are sources of some trace elements to streams. Water from a well in a nonirrigated area had 4,800 microg/L of selenium. Selenium concentrations in soil on the Oxford Tract were greater in areas previously or presently irrigated than in areas never irrigated. Some forage plants on the Oxford Tract had large selenium concentrations, including 180 mg/km in alfalfa. Most fish samples had selenium concentrations greater than the National Contaminant Biomonitoring Program 85th percentile. Selenium concentrations in aquatic plants, aquatic inverte- brates, and small mammals may be of concern to fish and wildlife because of possible food-chain bioconcentration. Selenium concentrations in bird samples indicate selenium contamination of biota on the Oxford Tract. Mallard breasts had selenium concentrations exceeding a guideline for human consumption. The maximum selenium concentration in biota was 50 microg/g dry weight in a bird liver from the Oxford Tract. In some fish samples, arsenic, cadmium, copper, and zinc exceeded background concentrations, but concentrations were not toxic. Mercury concentrations in 16 fish samples exceeded the background concentration. Ten mercury concentrations in fish exceeded a guideline for mercury in food for consumption by pregnant women.

  4. Water-quality assessment of the upper Snake River basin, Idaho and western Wyoming; summary of aquatic biological data for surface water through 1992

    USGS Publications Warehouse

    Maret, Terry R.

    1995-01-01

    The 35,800-square-mile upper Snake River Basin in eastern Idaho and western Wyoming was one of 20 areas selected for water-quality study under the National Water-Quality Assessment Program. As part of the initial phase of the study, data were compiled to describe the current (1992) and historical aquatic biological conditions of surface water in the basin. This description of natural and human environmental factors that affect aquatic life provides the framework for evaluating the status and trends of aquatic biological conditions in streams of the basins. Water resource development and stream alterations, irrigated agriculture, grazing, aquaculture, and species introductions have affected stream biota in the upper Snake River Basin. Cumulative effects of these activities have greatly altered cold-water habitat and aquatic life in the middle Snake River reach (Milner Dam to King Hill). Most of the aquatic Species of Special Concern in the basin , consisting of eight native mollusks and three native fish species, are in this reach of the Snake River. Selected long-term studies, including comprehensive monitoring on Rock Creek, have shown reduced pollutant loadings as a result of implementing practice on cropland; however, aquatic life remains affected by agricultural land use. Community level biological data are lacking for most of the streams in the basin, especially for large river. Aquatic life used to assess water quality of the basin includes primarily macroinvertebrate and fish communities. At least 26 different macroinvertebrate and fish community metrics have been utilized to assess water quality of the basin. Eight species of macroinvertebrates and fish are recognized as Species of Special Concern. The native fish faunas of the basin are composed primarily of cold-water species representing 5 families and 26 species. An additional 13 fish species have been introduced to the basin. Concentrations of synthetic organic compounds and trace-element contaminants

  5. Assessing the Fauna of Aquatic Insects for Possible Use for Malaria Vector Control in Large River, Central Iran.

    PubMed

    Shayeghi, Mansoureh; Nejati, Jalil; Shirani-Bidabadi, Leila; Koosha, Mona; Badakhshan, Mehdi; Mohammadi Bavani, Mulood; Arzamani, Kourosh; Choubdar, Nayyereh; Bagheri, Fatemeh; Saghafipour, Abedin; Veysi, Arshad; Karimian, Fateh; Akhavan, Amir Ahamd; Vatandoost, Hassan

    2015-01-01

    Insects with over 30,000 aquatic species are known as very successful arthropods in freshwater habitats. Some of them are applied as biological indicators for water quality control, as well as the main food supply for fishes and amphibians. The faunistic studies are the basic step in entomological researches; the current study was carried out emphasizing on the fauna of aquatic insects in Karaj River, northern Iran. A field study was carried out in six various sampling site of Karaj River during spring 2013. The aquatic insects were collected using several methods such as D-frame nets, dipping and direct search on river floor stones. Specimens were collected and preserved in Ethanol and identified by standard identification keys. Totally, 211 samples were collected belonging to three orders; Plecoptera, Trichoptera and Ephemeroptera. Seven genuses (Perla, Isoperla, Hydropsyche, Cheumatopsyche, Baetis, Heptagenia and Maccafferium) from five families (Perlidae, Perlodidae, Hydropsychidae, Batidae, Heptagenidae) were identified. The most predominant order was Plecoptera followed by Trichoptera. Karaj River is a main and important river, which provides almost all of water of Karaj dam. So, identification of aquatic species which exist in this river is vital and further studies about systematic and ecological investigations should be performed. Also, monitoring of aquatic biota by trained health personnel can be a critical step to describe water quality in this river. Understanding the fauna of aquatic insects will provide a clue for possible biological control of medically important aquatic insects such as Anopheles as the malaria vectors.

  6. A Modelling Framework to Assess the Effect of Pressures on River Abiotic Habitat Conditions and Biota

    PubMed Central

    Kail, Jochem; Guse, Björn; Radinger, Johannes; Schröder, Maria; Kiesel, Jens; Kleinhans, Maarten; Schuurman, Filip; Fohrer, Nicola; Hering, Daniel; Wolter, Christian

    2015-01-01

    River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a modelling framework was further developed and tested to assess the effect of pressures at different spatial scales on reach-scale habitat conditions and biota. Ecohydrological and 1D hydrodynamic models were used to predict discharge and water quality at the catchment scale and the resulting water level at the downstream end of a study reach. Long-term reach morphology was modelled using empirical regime equations, meander migration and 2D morphodynamic models. The respective flow and substrate conditions in the study reach were predicted using a 2D hydrodynamic model, and the suitability of these habitats was assessed with novel habitat models. In addition, dispersal models for fish and macroinvertebrates were developed to assess the re-colonization potential and to finally compare habitat suitability and the availability / ability of species to colonize these habitats. Applicability was tested and model performance was assessed by comparing observed and predicted conditions in the lowland Treene River in northern Germany. Technically, it was possible to link the different models, but future applications would benefit from the development of open source software for all modelling steps to enable fully automated model runs. Future research needs concern the physical modelling of long-term morphodynamics, feedback of biota (e.g., macrophytes) on abiotic habitat conditions, species interactions, and empirical data on the hydraulic habitat suitability and dispersal abilities of macroinvertebrates. The modelling framework is flexible and allows for including additional models and investigating different research and management questions, e.g., in climate impact research as well

  7. Aquatic cycling-What do we know? A scoping review on head-out aquatic cycling.

    PubMed

    Rewald, Stefanie; Mesters, Ilse; Lenssen, Antoine F; Bansi, Jens; Lambeck, Johan; de Bie, Rob A; Waller, Benjamin

    2017-01-01

    Over the past few years, aquatic cycling has become a trending fitness activity. However, the literature has not been reviewed exhaustively. Therefore, using scoping review methodology, the aim of this review was to explore the current state of the literature concerning aquatic cycling. This study specifically focused on study designs, populations and outcomes. A comprehensive search of seven databases (PubMed, MEDLINE, Cinahl, Embase, PEDro,Web of Science, WorldCat) was conducted up to 30th September 2016. GoogleScholar, World Cat, ResearchGate, specific aquatic therapy websites and aquatic therapy journals were searched to identify additional literature. Full-text publications in English, German or Dutch were included. Studies were included when the intervention involved head-out cycling carried out in 10° to 35° Celsius water. Exclusion criteria were the use of wet suits or confounding interventions that would affect participants' homeostasis. 63 articles were included and the study parameters of these studies were summarized. Using three grouping themes, included studies were categorised as 1) single session tests comparing aquatic versus land cycling, or 2) aquatic cycling only sessions investigating different exercise conditions and 3) aquatic cycling intervention programmes. Although the experimental conditions differed noticeably across the studies, shared characteristics were identified. Cardiovascular parameters were investigated by many of the studies with the results suggesting that the cardiac demand of aquatic cycling seems similar to land-based cycling. Only six studies evaluated the effect of aquatic cycling interventions. Therefore, future research should investigate the effects of aquatic cycling interventions, preferably in individuals that are expected to gain health benefits from aquatic cycling. Moreover, this comprehensive outline of available literature could serve as a starting point for systematic reviews or clinical studies on the

  8. Aquatic cycling—What do we know? A scoping review on head-out aquatic cycling

    PubMed Central

    Bansi, Jens; Lambeck, Johan; de Bie, Rob A.; Waller, Benjamin

    2017-01-01

    Over the past few years, aquatic cycling has become a trending fitness activity. However, the literature has not been reviewed exhaustively. Therefore, using scoping review methodology, the aim of this review was to explore the current state of the literature concerning aquatic cycling. This study specifically focused on study designs, populations and outcomes. A comprehensive search of seven databases (PubMed, MEDLINE, Cinahl, Embase, PEDro,Web of Science, WorldCat) was conducted up to 30th September 2016. GoogleScholar, World Cat, ResearchGate, specific aquatic therapy websites and aquatic therapy journals were searched to identify additional literature. Full-text publications in English, German or Dutch were included. Studies were included when the intervention involved head-out cycling carried out in 10° to 35° Celsius water. Exclusion criteria were the use of wet suits or confounding interventions that would affect participants’ homeostasis. 63 articles were included and the study parameters of these studies were summarized. Using three grouping themes, included studies were categorised as 1) single session tests comparing aquatic versus land cycling, or 2) aquatic cycling only sessions investigating different exercise conditions and 3) aquatic cycling intervention programmes. Although the experimental conditions differed noticeably across the studies, shared characteristics were identified. Cardiovascular parameters were investigated by many of the studies with the results suggesting that the cardiac demand of aquatic cycling seems similar to land-based cycling. Only six studies evaluated the effect of aquatic cycling interventions. Therefore, future research should investigate the effects of aquatic cycling interventions, preferably in individuals that are expected to gain health benefits from aquatic cycling. Moreover, this comprehensive outline of available literature could serve as a starting point for systematic reviews or clinical studies on the

  9. Increasing synchrony of high temperature and low flow in western North American streams: double trouble for coldwater biota?

    USGS Publications Warehouse

    Arismendi, Ivan; Safeeq, Mohammad; Johnson, Sherri L.; Dunham, Jason B.; Haggerty, Roy

    2013-01-01

    Flow and temperature are strongly linked environmental factors driving ecosystem processes in streams. Stream temperature maxima (Tmax_w) and stream flow minima (Qmin) can create periods of stress for aquatic organisms. In mountainous areas, such as western North America, recent shifts toward an earlier spring peak flow and decreases in low flow during summer/fall have been reported. We hypothesized that an earlier peak flow could be shifting the timing of low flow and leading to a decrease in the interval between Tmax_w and Qmin. We also examined if years with extreme low Qmin were associated with years of extreme high Tmax_w. We tested these hypotheses using long32 term data from 22 minimally human-influenced streams for the period 1950-2010. We found trends toward a shorter time lag between Tmax_w and Qmin over time and a strong negative association between their magnitudes. Our findings show that aquatic biota may be increasingly experiencing narrower time windows to recover or adapt between these extreme events of low flow and high temperature. This study highlights the importance of evaluating multiple environmental drivers to better gauge the effects of the recent climate variability in freshwaters.

  10. The sensitivity of aquatic insects to divalent metals: a comparative analysis of laboratory and field data.

    PubMed

    Brix, Kevin V; DeForest, David K; Adams, William J

    2011-09-15

    Laboratory studies have traditionally indicated that aquatic insects are relatively insensitive to metals while field studies have suggested them to be among the most sensitive aquatic invertebrate taxa. We reviewed and synthesized available studies in the literature to critically assess why this discrepancy exists. Despite the intense effort to study the effects of metals on aquatic biota over the past several decades, we found studies specific to insects to still be relatively limited. In general, the discrepancy between laboratory and field studies continues with few efforts having been made to elucidate the ecological and physiological mechanisms that underlie the relative sensitivity (or insensitivity) of aquatic insects to metals. However, given the limited data available, it appears that aquatic insects are indeed relatively insensitive to acute metal exposures. In contrast, we suggest that some aquatic insect taxa may be quite sensitive to chronic metal exposure and in some cases may not be protected by existing water quality criteria for metals. The discrepancy between laboratory and field studies with respect to chronic sensitivity appears to largely be driven by the relatively short exposure periods in laboratory studies as compared to field studies. It also appears that, in some cases, the sensitivity of aquatic insects in field studies may be the result of direct effects on primary producers, which lead to indirect effects via the food chain on aquatic insects. Finally, available evidence suggests that diet is an important source of metal accumulation in insects, but to date there have been no conclusive studies evaluating whether dietary metal accumulation causes toxicity. There is a clear need for developing a more mechanistic understanding of aquatic insect sensitivity to metals in long-term laboratory and field studies. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Field screening of water, soil, bottom sediment, and biota associated with irrigation drainage in the Dolores Project and the Macos River basin, southwestern Colorado, 1994

    USGS Publications Warehouse

    Butler, D.L.; Osmundson, B.C.; Krueger, R.P.

    1997-01-01

    A reconnaissance investigation for the National Irrigation Water Quality Program in 1990 indicated elevated selenium concentrations in some water and biota samples collected in the Dolores Project in southwestern Colorado. High selenium concentrations also were indicated in bird samples collected in the Mancos Project in 1989. In 1994, field screenings were done in parts of the Dolores Project and Mancos River Basin to collect additional selenium data associated with irrigation inthose areas. Selenium is mobilized from soils in newly irrigated areas of the Dolores Project called the Dove Creek area, which includes newly (since 1987) irrigated land north of Cortez and south of Dove Creek.Selenium was detected in 18 of 20stream samples, and the maximum concentration was 12micrograms per liter. The Dove Creek area is unique compared to other study areas of the National Irrigation Water Quality Program becauseselenium concentrations probably are indicative of initial leaching conditions in a newly irrigated area.Selenium concentrations in nine shallow soil samples from the Dove Creek area ranged from 0.13 to 0.20 micrograms per gram. Selenium concentrations in bottom sediment from six ponds were less than the level of concern for fish and wildlife of 4 micrograms per gram. Many biota samples collected in the Dove Creek area had elevated selenium concentrations when compared to various guidelines and effect levels,although selenium concentrations in water, soil, and bottom sediment were relatively low. Selenium concentrations in 12 of 14 aquatic-invertebratesamples from ponds exceeded 3 micrograms per gram dry weight, a dietary guideline for protection of fish and wildlife. The mean seleniumconcentration of 10.3 micrograms per gram dry weight in aquatic bird eggs exceeded the guideline for reduced hatchability of 8 micrograms per gramdry weight. Two ponds in the Dove Creek area had a high selenium hazard rating based on a new protocol for assessing selenium hazard in

  12. Pesticide toxicity index for freshwater aquatic organisms

    USGS Publications Warehouse

    Munn, Mark D.; Gilliom, Robert J.

    2001-01-01

    The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 75 of the 83 pesticide compounds measured in NAWQA samples, but with a wide range of bioassays per compound (1 to 65). There were a total of 2,824 bioassays for the 75 compounds, including 287 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a nonlethal response) for freshwater cladocerans, 585 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 1,952 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups.While the PTI does not determine whether water in a sample is toxic, its values can be used to rank or compare the toxicity of samples or sites on a relative basis for use in further analysis or

  13. Assessing the effects of legacy contaminants on egg and nestling survival of Tree Swallows in Great Lakes Areas of Concern (presentation)

    EPA Science Inventory

    Great Lakes Areas of Concern (AOCs) are affected by many stressors, some of which are environmental contaminants including PCBs, PBDEs, persistent organochlorine pesticides, dioxins, benzenes, and other chemicals. These toxicants can accumulate in aquatic biota and ultimately tra...

  14. Assessing the effects of legacy contaminants on egg and nestling survival of tree swallows in Great Lakes Areas of Concern

    EPA Science Inventory

    Great Lakes Areas of Concern (AOCs) are affected by many stressors, some of which are environmental contaminants including PCBs, PBDEs, persistent organochlorine pesticides, dioxins, benzenes, and other chemicals. These toxicants can accumulate in aquatic biota and ultimately tra...

  15. LEVELS OF SYNTHETIC MUSKS COMPOUNDS IN AQUATIC ...

    EPA Pesticide Factsheets

    Synthetic musk compounds are consumer chemicals manufactured as fragrance materials Due to their high worldwide usage and release, they frequently occur in the aquatic and marine environments. The U.S. EPA (ORD, Las Vegas) developed surface-water monitoring methodology and conducted a one-year monthly monitoring of synthetic musks in water and biota from Lake Mead (Nevada) as well as from combined sewage effluent streams feeding Lake Mead. Presented are the overview of the chemistry, the monitoring methodology, and the significance of synthetic musk compounds in the aquatic environment. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than p

  16. Long-term affects of experimental flows on riverine biota below a reservoir

    NASA Astrophysics Data System (ADS)

    Robinson, Chris; Ortlepp, Johannes

    2010-05-01

    Large dams have altered the flow regime of most rivers on the globe with consequent effects on riverine biota. Experimental flows (multiple floods per year) have been used on the regulated Spöl River below Livigno Reservoir for over 9 years to enhance the ecological condition of the river. The flow program has improved the brown trout fishery in the river as indicated by an increased number of redds. Floods have reset periphyton assemblages from a moss-dominated streambed to one dominated by diatoms and patches of filamentous algae. Zoobenthic assemblages have shown dramatic shifts in benthic structure in line with predictions from altered state models. Ecosystem regime shifts have been characterized with increases in parameter variances followed by periods of stable states. The system appears to be entering a second zoobenthic regime shift after year 8, perhaps in response to biotic interactions due to changes in the fishery. The response patterns clearly show that a long-term perspective must be in place when assessing biotic responses to changes in physical habitat properties resulting from flow experiments.

  17. Response of soil biota to vineyard interrow soil cultivation can be altered by the surrounding landscape

    NASA Astrophysics Data System (ADS)

    Zaller, Johann; Buchholz, Jacob; Querner, Pascal; Paredes, Daniel; Kratschmer, Sophie; Schwantzer, Martina; Winter, Silvia; Strauss, Peter; Bauer, Thomas; Burel, Françoise; Guernion, Muriel; Scimia, Jennifer; Nicolai, Annegret; Cluzeau, Daniel

    2017-04-01

    Ecosystem services provided by viticultural landscapes result from interactions between management intensity, soil properties, organisms inhabiting these landscapes, and the diversity and structure of the surrounding landscape. However, there is actually very little known to what extent these different factors influence the abundance and diversity of various soil biota. In this study we examined (i) to what extent different soil management intensities of interrows affect the activity and diversity of soil biota (earthworms, Collembola, litter decomposition), (ii) the role of soil properties in influencing these effects and (iii) whether the surrounding landscape structure is altering these interactions. We collected data in 16 vineyards in Austria embedded in landscapes with varying structure (i.e. from structurally simple to complex) and assessed earthworms (hand sorting), Collembola (pitfall trapping and soil coring), litter decomposition (tea bag method). Additionally, soil physical (water infiltration, aggregate stability, porosity, bulk density, soil texture) and chemical (pH, soil carbon content, cation exchange capacity, potassium, phosphorus) parameters were assessed. The landscape surrounding our vineyards within a radius of 750 m was assessed by field mapping using a geographical information system. Results showed that different soil biota/processes are differently affected by soil cultivation intensity and soil properties. Parameters describing the surrounding landscape interacted more with the responses of Collembola to soil cultivation than with earthworms or litter decomposition. These investigations are part of the transdisciplinary BiodivERsA project VineDivers (www.vinedivers.eu) and will ultimately lead into management recommendations for various stakeholders.

  18. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bartoshesky, J.; Price, R.; DeMuro, J.

    In recent years acid deposition has become a serious concern internationally. Scientific literature has documented the acidification of numerous lakes and streams in North America and Scandinavia resulting in the depletion or total loss of fisheries and other aquatic biota. Liming represents the only common corrective practice aimed specifically at remediating an affected acid receptor. This report reviews a range of liming technologies and liming materials, as well as the effect of surface-water liming on water quality and aquatic biota. As background to the liming discussion, the hydrologic cycle and the factors that make surface waters sensitive to acid depositionmore » are also discussed. Finally, a brief review of some of the liming projects that have been conducted, or are currently in operation is presented, giving special emphasis to mitigation efforts in Maryland. Liming has been effectively used to counteract surface-water acidification in parts of Scandinavia, Canada, and the U.S. To date, liming has generally been shown to improve physical and chemical conditions and enhance the biological recovery of aquatic ecosystems affected by acidification.« less

  19. Deriving Freshwater Quality Criteria for Iron, Lead, Nickel, and Zinc for Protection of Aquatic Life in Malaysia

    PubMed Central

    Shuhaimi-Othman, M.; Nadzifah, Y.; Nur-Amalina, R.; Umirah, N. S.

    2012-01-01

    Freshwater quality criteria for iron (Fe), lead (Pb), nickel (Ni), and zinc (Zn) were developed with particular reference to aquatic biota in Malaysia, and based on USEPA's guidelines. Acute toxicity tests were performed on eight different freshwater domestic species in Malaysia which were Macrobrachium lanchesteri (prawn), two fish: Poecilia reticulata and Rasbora sumatrana, Melanoides tuberculata (snail), Stenocypris major (ostracod), Chironomus javanus (midge larvae), Nais elinguis (annelid), and Duttaphrynus melanostictus (tadpole) to determine 96 h LC50 values for Fe, Pb, Ni, and Zn. The final acute value (FAV) for Fe, Pb, Ni, and Zn were 74.5, 17.0, 165, and 304.9 μg L−1, respectively. Using an estimated acute-to-chronic ratio (ACR) of 8.3, the value for final chronic value (FCV) was derived. Based on FAV and FCV, a criterion maximum concentration (CMC) and a criterion continuous concentration (CCC) for Fe, Pb, Ni, and Zn that are 37.2, 8.5, 82.5, and 152.4 μg L−1 and 9.0, 2.0, 19.9, and 36.7 μg L−1, respectively, were derived. The results of this study provide useful data for deriving national or local water quality criteria for Fe, Pb, Ni, and Zn based on aquatic biota in Malaysia. Based on LC50 values, this study indicated that N. elinguis, M. lanchesteri, N. elinguis, and R. sumatrana were the most sensitive to Fe, Pb, Ni, and Zn, respectively. PMID:22919358

  20. SOIL N AND C GEOGRAPHY OF THE SALMON RIVER WATERSHED AND THE OREGON COAST

    EPA Science Inventory

    To help establish restorative criteria of salmon runs in the Pacific Northwest, resource inventories on affected watersheds are a critical component of this process. Diverse soil and geology influence the rich terrestrial and aquatic biota of the Oregon Coast. We characterized ...

  1. Pesticide toxicity index for freshwater aquatic organisms, 2nd edition

    USGS Publications Warehouse

    Munn, Mark D.; Gilliom, Robert J.; Moran, Patrick W.; Nowell, Lisa H.

    2006-01-01

    The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with acute toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 124 of the 185 pesticide compounds measured in NAWQA samples, but with a wide range of available bioassays per compound (1 to 232). In the databases examined, there were a total of 3,669 bioassays for the 124 compounds, including 398 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a sublethal response) for freshwater cladocerans, 699 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 2,572 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide, and thus, is based on the concentration addition model of pesticide toxicity. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups. Although the PTI does not determine whether water in a sample is

  2. Is there a risk associated with the insect repellent DEET (N,N-diethyl-m-toluamide) commonly found in aquatic environments?

    USGS Publications Warehouse

    Costanzo, S.D.; Watkinson, A.J.; Murby, E.J.; Kolpin, D.W.; Sandstrom, M.W.

    2007-01-01

    DEET (N,N-diethyl-m-toluamide) is the active ingredient of most commercial insect repellents. This compound has commonly been detected in aquatic water samples from around the world indicating that DEET is both mobile and persistent, despite earlier assumptions that DEET was unlikely to enter aquatic ecosystems. DEET's registration category does not require an ecological risk assessment, thus information on the ecological toxicity of DEET is sparse. This paper reviews the presence of DEET in aqueous samples from around the world (e.g. drinking water, streams, open seawater, groundwater and treated effluent) with reported DEET concentrations ranging from 40–3000 ng L− 1. In addition, new DEET data collected from 36 sites in coastal waterways from eastern Australia (detections ranging from 8 to 1500 ng L− 1) are examined. A summary of new and existing toxicity data are discussed with an emphasis on preparing a preliminary risk assessment for DEET in the aquatic environment. Collated information on DEET in the aquatic environment suggests risk to aquatic biota at observed environmental concentrations is minimal. However, the information available was not sufficient to conduct a full risk assessment due to data deficiencies in source characterisation, transport mechanisms, fate, and ecotoxicity studies. These risks warrant further investigation due to the high frequency that this organic contaminant is detected in aquatic environments around the world.

  3. Diversity and distribution of aquatic insects in Southern Brazil wetlands: implications for biodiversity conservation in a Neotropical region.

    PubMed

    Maltchik, Leonardo; Dalzochio, Marina Schmidt; Stenert, Cristina; Rolon, Ana Silvia

    2012-03-01

    The selection of priority areas is an enormous challenge for biodiversity conservation. Some biogeographic methods have been used to identify the priority areas to conservation, and panbiogeography is one of them. This study aimed at the utilization of panbiogeographic tools, to identify the distribution patterns of aquatic insect genera, in wetland systems of an extensive area in the Neotropical region (approximately 280 000km2), and to compare the distribution of the biogeographic units identified by the aquatic insects, with the conservation units of Southern Brazil. We analyzed the distribution pattern of 82 genera distributed in four orders of aquatic insects (Diptera, Odonata, Ephemeroptera and Trichoptera) in Southern Brazil wetlands. Therefore, 32 biogeographic nodes corresponded to the priority areas for conservation of the aquatic insect diversity. Among this total, 13 were located in the Atlantic Rainforest, 16 in the Pampa and three amongst both biomes. The distribution of nodes showed that only 15% of the dispersion centers of insects were inserted in conservation units. The four priority areas pointed by node cluster criterion must be considered in further inclusions of areas for biodiversity conservation in Southern Brazil wetlands, since such areas present species from different ancestral biota. The inclusion of such areas into the conservation units would be a strong way to conserve the aquatic biodiversity in this region.

  4. Toxicological benchmarks for screening potential contaminants of concern for effects on aquatic biota: 1996 revision

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Suter, G.W. II; Tsao, C.L.

    1996-06-01

    This report presents potential screening benchmarks for protection of aquatic life form contaminants in water. Because there is no guidance for screening for benchmarks, a set of alternative benchmarks is presented herein. This report presents the alternative benchmarks for chemicals that have been detected on the Oak Ridge Reservation. It also presents the data used to calculate the benchmarks and the sources of the data. It compares the benchmarks and discusses their relative conservatism and utility. Also included is the updates of benchmark values where appropriate, new benchmark values, secondary sources are replaced by primary sources, and a more completemore » documentation of the sources and derivation of all values are presented.« less

  5. THE IMPORTANCE OF THE BIODIVERSITY OF SOIL BIOTA IN ARID ECOSYSTEMS

    EPA Science Inventory

    The importance of soil biota in maintaining ecosystem integrity is examined by a review of studies of soil processes and soil biota in arid ecosystems. In decomposition and mineralization processes, there is a temporal succession of microarthropod and nematode species. Tydeid mit...

  6. Short- and medium-chain chlorinated paraffins in aquatic foods from 18 Chinese provinces: Occurrence, spatial distributions, and risk assessment.

    PubMed

    Wang, Runhua; Gao, Lirong; Zheng, Minghui; Tian, Yiling; Li, Jingguang; Zhang, Lei; Wu, Yongning; Huang, Huiting; Qiao, Lin; Liu, Wenbin; Su, Guijin; Liu, Guorui; Liu, Ying

    2018-02-15

    Short-chain chlorinated paraffins (SCCPs) are classed as persistent organic pollutants and were included in the Stockholm Convention in May 2017. Large amounts of chlorinated paraffins (CPs) are produced in China than in any other countries. CPs can be released into the environment while being produced and used, and can bioaccumulate in aquatic biota and be ingested by humans. Dietary intake is the main route through which humans are exposed to CPs. It has previously been found that persistent organic pollutant concentrations are usually higher in aquatic foods than in other foods. The risk of human exposure to SCCPs in aquatic foods should therefore be of concerns. However, SCCP concentrations in aquatic foods have not been systematically studied. A total of 1620 aquatic food samples were collected, and 18 pooled samples were analyzed by two-dimensional gas chromatography coupled with electron-capture negative-ionization time-of-flight mass spectrometry. The mean SCCP and MCCP concentrations were 1472 and 80.5ng/gwet weight, respectively. The dominant SCCP and MCCP congener groups were C 10 Cl 6-7 and C 14 Cl 7-8 , respectively. The concentrations were much higher than those have been found in aquatic foods in other countries. The CP concentrations in the samples consumed by local people from eastern and southern China were higher than the concentrations in samples from central and western China. Risk assessment results indicated that SCCPs and MCCPs in aquatic foods do not pose significant risks to residents of China. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Biological assessment of aquatic pollution: a review, with emphasis on plants as biomonitors.

    PubMed

    Doust, J L; Schmidt, M; Doust, L L

    1994-05-01

    In a number of disciplines including ecology, ecotoxicology, water quality management, water resource management, fishery biology etc., there is significant interest in the testing of new materials, environmental samples (of water or sediments) and specific sites, in terms of their effects on biota. In the first instance, we consider various sources of aquatic pollution, sources typically associated with developed areas of the world. Historically, much water quality assessment has been performed by researchers with a background in chemistry or engineering, thus chemical analysis was a dominant form of assessment. However, chemical analyses, particularly of such materials as organochlorines and polyaromatic hydrocarbons can be expensive, and local environmental factors may cause the actual exposure of an organism to be little correlated with chemical concentrations in the surrounding water or sediments. To a large extent toxicity testing has proceeded independently of environmental quality assessment in situ, and the work has been done by different, and differently-trained researchers. Here we attempt to bring together the various forms of biological assessment of aquatic pollution, because in our opinion it is worth developing a coherent framework for the application of this powerful tool. Biotic assessment in its most primitive form involves the simple tracking of mortality in exposed organisms. However, in most natural environments it is extended, chronic exposure to contaminants that has the most wide-ranging and irreversible repercussions--thus measures of sub-lethal impairment are favoured. From an ecological standpoint, it is most valuable to assess ecological effects by direct study of in situ contaminant body burdens and impairment of growth and reproduction compared with 'clean' sites. A distinction is made here between bioindication and biomonitoring, and a case is made for including aquatic macrophytes (angiosperms) in studies of contaminant levels and

  8. Propagation and Establishment of Native Plants for Vegetative Restoration of Aquatic Ecosystems

    DTIC Science & Technology

    2013-06-01

    diverse native plant communities in aquatic systems. We document the successful application of these techniques in a number of aquatic ecosystems...Aquatic Plant Control Research Program (APCRP) for establishing native aquatic plants in reservoirs and other water bodies. These techniques should...that some control techniques may negatively affect efforts to establish native vegetation. Establishing native aquatic vegetation is not an exact

  9. Comparison and applicability analysis of models for estimating radiological dose rates of freshwater biota

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaofeng; Yang, Zongzhen; Qin, Chunli

    2018-01-01

    A number of inter-comparisons of non-human biota radiation assessment models have been fulfilled by international researchers and organizations. This paper describes the radiological impact to reference biota in Chinese inland nuclear power plant scenario, by using RESRAD-Biota, ERICA and R&D 128. The estimation results are ranging from 6.1×10-3μGy/h to 6.17×10-2μGy/h, mainly contributed by 134Cs and 137Cs, obviously below recommended limits and thus prove the biota in reservoir can be adequately protected from effluent discharge. By comparing models characteristics and performances in exercise, we conclude the ERICA tool reveals more applicability in Chinese nuclear sites and propose several suggestions to establish native framework for non-human biota assessment.

  10. Literature Review and Database of Relations Between Salinity and Aquatic Biota: Applications to Bowdoin National Wildlife Refuge, Montana

    USGS Publications Warehouse

    Gleason, Robert A.; Tangen, Brian A.; Laubhan, Murray K.; Finocchiaro, Raymond G.; Stamm, John F.

    2009-01-01

    Long-term accumulation of salts in wetlands at Bowdoin National Wildlife Refuge (NWR), Mont., has raised concern among wetland managers that increasing salinity may threaten plant and invertebrate communities that provide important habitat and food resources for migratory waterfowl. Currently, the U.S. Fish and Wildlife Service (USFWS) is evaluating various water management strategies to help maintain suitable ranges of salinity to sustain plant and invertebrate resources of importance to wildlife. To support this evaluation, the USFWS requested that the U.S. Geological Survey (USGS) provide information on salinity ranges of water and soil for common plants and invertebrates on Bowdoin NWR lands. To address this need, we conducted a search of the literature on occurrences of plants and invertebrates in relation to salinity and pH of the water and soil. The compiled literature was used to (1) provide a general overview of salinity concepts, (2) document published tolerances and adaptations of biota to salinity, (3) develop databases that the USFWS can use to summarize the range of reported salinity values associated with plant and invertebrate taxa, and (4) perform database summaries that describe reported salinity ranges associated with plants and invertebrates at Bowdoin NWR. The purpose of this report is to synthesize information to facilitate a better understanding of the ecological relations between salinity and flora and fauna when developing wetland management strategies. A primary focus of this report is to provide information to help evaluate and address salinity issues at Bowdoin NWR; however, the accompanying databases, as well as concepts and information discussed, are applicable to other areas or refuges. The accompanying databases include salinity values reported for 411 plant taxa and 330 invertebrate taxa. The databases are available in Microsoft Excel version 2007 (http://pubs.usgs.gov/sir/2009/5098/downloads/databases_21april2009.xls) and contain

  11. Choice of resolution by functional trait or taxonomy affects allometric scaling in soil food webs.

    PubMed

    Sechi, Valentina; Brussaard, Lijbert; De Goede, Ron G M; Rutgers, Michiel; Mulder, Christian

    2015-01-01

    Belowground organisms often display a shift in their mass-abundance scaling relationships due to environmental factors such as soil chemistry and atmospheric deposition. Here we present new empirical data that show strong differences in allometric scaling according to whether the resolution at the local scale is based on a taxonomic or a functional classification, while only slight differences arise according to soil environmental conditions. For the first time, isometry (an inverse 1:1 proportion) is recognized in mass-abundance relationships, providing a functional signal for constant biomass distribution in soil biota regardless of discrete trophic levels. Our findings are in contrast to those from aquatic ecosystems, in that higher trophic levels in soil biota are not a direct function of increasing body mass.

  12. Microcystin in aquatic food webs of the Baltic and Chesapeake Bay regions

    NASA Astrophysics Data System (ADS)

    Bukaveckas, Paul A.; Lesutienė, Jūratė; Gasiūnaitė, Zita R.; Ložys, Linas; Olenina, Irina; Pilkaitytė, Renata; Pūtys, Žilvinas; Tassone, Spencer; Wood, Joseph

    2017-05-01

    We undertook a comparative study of the James River Estuary, a sub-estuary of Chesapeake Bay, and the Curonian Lagoon, a sub-estuary of the Baltic Sea, to better understand the factors that determine the presence and persistence of algal toxins in food webs. Over a 2-year period, we measured microcystin concentrations in water, sediment and biota (fish and shellfish) at both sites. Across both food webs we found highest levels of microcystin among consumers of suspended particulate matter, including planktivorous fishes and filter-feeding shellfish, and lower levels of toxin among piscivores, scavengers and benthic omnivores. Despite similar levels of microcystin in the water column at the two sites, we observed higher toxin levels in fish and sediments of the Curonian Lagoon. We attribute this difference to the legacy of prior toxic cyanobacteria blooms in the Curonian Lagoon and hydrologic factors that result in a predominance of autochthonously-derived organic matter in the sediments at this site. Our results suggest that a consideration of species-specific differences in feeding habits, and organic matter sources supporting food webs are important to understanding the accumulation and persistence of algal toxins in food webs and should therefore be considered in assessment of risks to aquatic biota and human health.

  13. Concentrations of metals and trace elements in aquatic biota associated with abandoned mine lands in the Whiskeytown National Recreation Area and nearby Clear Creek watershed, Shasta County, northwestern California, 2002-2003

    USGS Publications Warehouse

    Hothem, Roger L.; May, Jason T.; Gibson, Jennifer K.; Brussee, Brianne E.

    2015-01-01

    Compared with other recently evaluated mine-impacted watersheds in northern California, invertebrates, amphibians, and fish from sites within the Upper Clear Creek watershed tended to have significantly lower concentrations of Hg than at most other sites. For other metals and trace elements, Upper Clear Creek sites were only compared with the Deer Creek watershed, Nevada County, California. Copper from both Willow Creek sites (WLCC and WLTH) in the Clear Creek watershed was the only metal with concentrations in biota that were significantly higher than biota from Deer Creek

  14. Fire and aquatic ecosystems in forested biomes of North America

    USGS Publications Warehouse

    Gresswell, Robert E.

    1999-01-01

    Synthesis of the literature suggests that physical, chemical, and biological elements of a watershed interact with long-term climate to influence fire regime, and that these factors, in concordance with the postfire vegetation mosaic, combine with local-scale weather to govern the trajectory and magnitude of change following a fire event. Perturbation associated with hydrological processes is probably the primary factor influencing postfire persistence of fishes, benthic macroinvertebrates, and diatoms in fluvial systems. It is apparent that salmonids have evolved strategies to survive perturbations occurring at the frequency of wildland fires (100a??102 years), but local populations of a species may be more ephemeral. Habitat alteration probably has the greatest impact on individual organisms and local populations that are the least mobile, and reinvasion will be most rapid by aquatic organisms with high mobility. It is becoming increasingly apparent that during the past century fire suppression has altered fire regimes in some vegetation types, and consequently, the probability of large stand-replacing fires has increased in those areas. Current evidence suggests, however, that even in the case of extensive high-severity fires, local extirpation of fishes is patchy, and recolonization is rapid. Lasting detrimental effects on fish populations have been limited to areas where native populations have declined and become increasingly isolated because of anthropogenic activities. A strategy of protecting robust aquatic communities and restoring aquatic habitat structure and life history complexity in degraded areas may be the most effective means for insuring the persistence of native biota where the probability of large-scale fires has increased.

  15. Efficacy of aquatic therapy for multiple sclerosis: a systematic review.

    PubMed

    Corvillo, Iluminada; Varela, Enrique; Armijo, Francisco; Alvarez-Badillo, Antonio; Armijo, Onica; Maraver, Francisco

    2017-12-01

    Multiple sclerosis (MS) is a chronic, inflammatory, progressive, disabling autoimmune disease affecting the central nervous system. Symptoms and signs of MS vary widely and patients may lose their ability to walk. To date the benefits of aquatic therapy often used for rehabilitation in MS patients have not been reviewed. The aim of this study was to systematically review the current state of aquatic treatment for persons with MS (hydrotherapy, aquatic therapy, aquatic exercises, spa therapy) and to evaluate the scientific evidence supporting the benefits of this therapeutic option. The databases PubMed, Scopus, WoS and PEDro were searched to identify relevant reports published from January 1, 2011 to April 30, 2016. Of 306 articles identified, only 10 fulfilled the inclusion criteria: 5 randomized controlled, 2 simple randomized quasi-experimental, 1 semi-experimental, 1 blind controlled pilot and 1 pilot. Evidence that aquatic treatment improves quality of life in affected patients was very good in two studies, good in four, fair in two and weak in two.

  16. Investigation of Freshwater Mussels (Unionidae) at Selected Sites in the Lower Ohio and Cumberland Rivers, September 1990.

    DTIC Science & Technology

    1991-07-01

    tial for negatively affecting aquatic biota. Freshwater mussels, a resource with economic, ecological, and cultural value, could be affected by...Chapor I (WES) conduct a survey of freshwater mussels (Family: Unionidae) at two areas likely to be affected by proposed water resource developments...TECHNICAL REPORT EL-91-9 S- iINVESTIGATION OF FRESHWATER MUSSELS (UNIONIDAE) AT SELECTED SITES IN THE LOWER OHIO AND CUMBERLAND RIVERS, SEPTEMBER

  17. VASCULAR PLANTS AS ENGINEERS OF OXYGEN IN AQUATIC SYSTEMS

    EPA Science Inventory

    The impact of organisms on oxygen is one of the most dramatic examples of ecosystem engineering on Earth. In aquatic systems, which have much lower oxygen concentrations than the atmosphere, vascular aquatic plants can affect oxygen concentrations significantly not only on long t...

  18. MICROBIAL ACTIVITIES FOR THE REMEDIATION OF MERCURY CONTAMINATION

    EPA Science Inventory

    Methylmercury (MeHg) accumulation by aquatic biota could be reduced by stimulating bacterial degradation of MeHg and the reduction of Hg(II) to volatile Hg to zero power. Reduction of Hg(II) affects MeHg production by substrate limitation. The potential of bacterial reduction of ...

  19. Life cycle impacts of topsoil erosion on aquatic ecosystems: case study on Eucalyptus globulus forest

    NASA Astrophysics Data System (ADS)

    Quinteiro, Paula; Van de Broek, Marijn; Cláudia Dias, Ana; Ridoutt, Bradley; Arroja, Luís

    2016-04-01

    High concentrations of suspended solids (SS), particularly in the clay and silt size fractions, reaching lotic environments and remaining in suspension can be a significant stressors to the biodiversity of these aquatic systems, degrading the water quality and directly affecting the aquatic biota, namely macroinvertebrates, algae and macrophytes. This damage is presently not considered in Life Cycle Assessment studies. This study is devoted to the effects of SS into freshwater systems due to topsoil erosion by water (environmental mechanism), translated into damage to aquatic ecosystem diversity (endpoint impact category), namely to macroinvertebrates, algae and macrophytes. For this, we have developed a framework to conduct an erosion inventory using the WaTEM/SEDEM model and linked this with, a method to derive regional characterisation for endpoint damage on aquatic ecosystem diversity. A case study was performed for Eucalyptus globulus stands in Portugal, with a functional unit of one hectare of land under production forestry management. To demonstrate how this newly SS ecosystem method can help to improve the environmental assessment in forestry, results were compared with the earlier commonly used impact categories from ReCiPe method. The relevance of the impact from SS delivery to freshwater streams is shown, providing a more comprehensive assessment of the SS impact from land use systems on aquatic environments. The SS impacts ranged from 15.5 to 1234.9 PDF.m3.yr.ha-1.revolution-1 for macroinvertebrates, and from 5.2 to 411.9 PDF.m3.yr.ha-1.revolution-1 for algae and macrophytes. For some stands, SS potential impacts on macroinvertebrates have the same order of magnitude than freshwater eutrophication, freshwater ecotoxicity, terrestrial ecotoxicity and terrestrial acidification impacts. For algae and macrophytes, most of the stands present SS impacts of the same order of magnitude as terrestrial ecotoxicity, one order of magnitude higher than freshwater

  20. Ecological Dose Modeling of Aquatic and Riparian Receptors to Strontium-90 with an Emphasis on Radiosensitive Organs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Poston, Ted M.; Traub, Richard J.; Antonio, Ernest J.

    2011-07-20

    The 100-NR-2 site is the location of elevated releases of strontium-90 to the Columbia River via contaminated groundwater. The resulting dose to aquatic and riparian receptors was evaluated in 2005 (DOE 2009) and compared to U.S. Department of Energy (DOE) dose guidance values. We have conducted additional dose assessments for a broader spectrum of aquatic and riparian organisms using RESRAD Biota and specific exposure scenarios. Because strontium-90 accumulates in bone, we have also modeled the dose to the anterior kidney, a blood-forming and immune system organ that lies close to the spinal column of fish. The resulting dose is primarilymore » attributable to the yttrium-90 progeny of strontium-90 and very little of the dose is associated with the beta emission from strontium-90. All dose modeling results were calculated with an assumption of secular equilibrium between strontium-90 and yttrum-90.« less

  1. Prevailing Negative Soil Biota Effect and No Evidence for Local Adaptation in a Widespread Eurasian Grass

    PubMed Central

    Wagner, Viktoria; Antunes, Pedro M.; Ristow, Michael; Lechner, Ute; Hensen, Isabell

    2011-01-01

    Background Soil biota effects are increasingly accepted as an important driver of the abundance and distribution of plants. While biogeographical studies on alien invasive plant species have indicated coevolution with soil biota in their native distribution range, it is unknown whether adaptation to soil biota varies among populations within the native distribution range. The question of local adaptation between plants and their soil biota has important implications for conservation of biodiversity and may justify the use of seed material from local provenances in restoration campaigns. Methodology/Principal Findings We studied soil biota effects in ten populations of the steppe grass Stipa capillata from two distinct regions, Europe and Asia. We tested for local adaptation at two different scales, both within (ca. 10–80 km) and between (ca. 3300 km) regions, using a reciprocal inoculation experiment in the greenhouse for nine months. Generally, negative soil biota effects were consistent. However, we did not find evidence for local adaptation: both within and between regions, growth of plants in their ‘home soil’ was not significantly larger relative to that in soil from other, more distant, populations. Conclusions/Significance Our study suggests that negative soil biota effects can prevail in different parts of a plant species' range. Absence of local adaptation points to the possibility of similar rhizosphere biota composition across populations and regions, sufficient gene flow to prevent coevolution, selection in favor of plasticity, or functional redundancy among different soil biota. From the point of view of plant - soil biota interactions, our findings indicate that the current practice of using seeds exclusively from local provenances in ecosystem restoration campaigns may not be justified. PMID:21479262

  2. The Fish Kill Mystery: Learning about Aquatic Communities

    ERIC Educational Resources Information Center

    Kosal, Erica F.

    2004-01-01

    This paper presents a case where students can learn about aquatic communities. In this case, students speculate on what may have caused a major fish kill in an estuary in North Carolina. In the process, they explore how land runoff and excess nutrients affect aquatic communities. They also learn about the complex life cycle of the dinoflagellate…

  3. Spatial heterogeneity of plant-soil feedback affects root interactions and interspecific competition.

    PubMed

    Hendriks, Marloes; Ravenek, Janneke M; Smit-Tiekstra, Annemiek E; van der Paauw, Jan Willem; de Caluwe, Hannie; van der Putten, Wim H; de Kroon, Hans; Mommer, Liesje

    2015-08-01

    Plant-soil feedback is receiving increasing interest as a factor influencing plant competition and species coexistence in grasslands. However, we do not know how spatial distribution of plant-soil feedback affects plant below-ground interactions. We investigated the way in which spatial heterogeneity of soil biota affects competitive interactions in grassland plant species. We performed a pairwise competition experiment combined with heterogeneous distribution of soil biota using four grassland plant species and their soil biota. Patches were applied as quadrants of 'own' and 'foreign' soils from all plant species in all pairwise combinations. To evaluate interspecific root responses, species-specific root biomass was quantified using real-time PCR. All plant species suffered negative soil feedback, but strength was species-specific, reflected by a decrease in root growth in own compared with foreign soil. Reduction in root growth in own patches by the superior plant competitor provided opportunities for inferior competitors to increase root biomass in these patches. These patterns did not cascade into above-ground effects during our experiment. We show that root distributions can be determined by spatial heterogeneity of soil biota, affecting plant below-ground competitive interactions. Thus, spatial heterogeneity of soil biota may contribute to plant species coexistence in species-rich grasslands. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  4. Plastic ingestion in aquatic-associated bird species in southern Portugal.

    PubMed

    Nicastro, Katy R; Lo Savio, Roberto; McQuaid, Christopher D; Madeira, Pedro; Valbusa, Ugo; Azevedo, Fábia; Casero, Maria; Lourenço, Carla; Zardi, Gerardo I

    2018-01-01

    Excessive use of plastics in daily life and the inappropriate disposal of plastic products are severely affecting wildlife species in both coastal and aquatic environments. Birds are top-predators, exposed to all threats affecting their environments, making them ideal sentinel organisms for monitoring ecosystems change. We set a baseline assessment of the prevalence of marine plastic litter affecting multi-species populations of aquatic birds in southern Portugal. By examining 160 stomach contents from 8 species of aquatic birds, we show that 22.5% were affected by plastic debris. Plastic was found in Ciconia ciconia, Larus fuscus and L. michahellis. Ciconia ciconia ingested the highest amount (number of items and total mass) of plastic debris. Polydimethylsiloxane (PDMS, silicones) was the most abundant polymer and was recorded only in C. ciconia. Plastic ingestion baseline data are of crucial importance to evaluate changes through time and among regions and to define management and conservation strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Distribution of polychlorinated biphenyls in an urban riparian zone affected by wastewater treatment plant effluent and the transfer to terrestrial compartment by invertebrates.

    PubMed

    Yu, Junchao; Wang, Thanh; Han, Shanlong; Wang, Pu; Zhang, Qinghua; Jiang, Guibin

    2013-10-01

    In this study, we investigated the distribution of polychlorinated biphenyls (PCBs) in a riparian zone affected by the effluent from a wastewater treatment plant (WWTP). River water, sediment, aquatic invertebrates and samples from the surrounding terrestrial compartment such as soil, reed plants and several land based invertebrates were collected. A relatively narrow range of δ(13)C values was found among most invertebrates (except butterflies, grasshoppers), indicating a similar energy source. The highest concentration of total PCBs was observed in zooplankton (151.1 ng/g lipid weight), and soil dwelling invertebrates showed higher concentrations than phytophagous insects at the riparian zone. The endobenthic oligochaete Tubifex tubifex (54.28 ng/g lw) might be a useful bioindicator of WWTP derived PCBs contamination. High bioaccumulation factors (BAFs) were observed in collected aquatic invertebrates, although the biota-sediment/soil accumulation factors (BSAF) remained relatively low. Emerging aquatic insects such as chironomids could carry waterborne PCBs to the terrestrial compartment via their lifecycles. The estimated annual flux of PCBs for chironomids ranged from 0.66 to 265 ng⋅m(-2)⋅y(-1). Although a high prevalence of PCB-11 and PCB-28 was found for most aquatic based samples in this riparian zone, the mid-chlorinated congeners (e.g. PCB-153 and PCB-138) became predominant among chironomids and dragonflies as well as soil dwelling invertebrates, which might suggest a selective biodriven transfer of different PCB congeners. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Fukushima nuclear accident: preliminary assessment of the risks to non-human biota.

    PubMed

    Aliyu, Abubakar Sadiq; Ramli, Ahmad Termizi; Garba, Nuraddeen Nasiru; Saleh, Muneer Aziz; Gabdo, Hamman Tukur; Liman, Muhammad Sanusi

    2015-02-01

    This study assesses the 'radio-ecological' impacts of Fukushima nuclear accident on non-human biota using the ERICA Tool, which adopts an internationally verified methodology. The paper estimates the impacts of the accident on terrestrial and marine biota based on the environmental data reported in literature for Japan, China, South Korea and the USA. Discernible impacts have been detected in the marine biota around Fukushima Daiichi nuclear power plant. This study confirms that the Fukushima accident had caused heavier damage to marine bionts compared with terrestrial flora and fauna, in Japan. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Aquatic and terrestrial organic matter in the diet of stream consumers: implications for mercury bioaccumulation.

    PubMed

    Jardine, Timothy D; Kidd, Karen A; Rasmussen, Joseph B

    2012-04-01

    The relative contribution of aquatic vs. terrestrial organic matter to the diet of consumers in fluvial environments and its effects on bioaccumulation of contaminants such as mercury (Hg) remain poorly understood. We used stable isotopes of carbon and nitrogen in a gradient approach (consumer isotope ratio vs. periphyton isotope ratio) across temperate streams that range in their pH to assess consumer reliance on aquatic (periphyton) vs. terrestrial (riparian vegetation) organic matter, and whether Hg concentrations in fish and their prey were related to these energy sources. Taxa varied in their use of the two sources, with grazing mayflies (Heptageniidae), predatory stoneflies (Perlidae), one species of water strider (Metrobates hesperius), and the fish blacknose dace (Rhinichthys atratulus) showing strong connections to aquatic sources, while Aquarius remigis water striders and brook trout (Salvelinus fontinalis) showed a weak link to in-stream production. The aquatic food source for consumers, periphyton, had higher Hg concentrations in low-pH waters, and pH was a much better predictor of Hg in predatory invertebrates that relied mainly on this food source vs. those that used terrestrial C. These findings suggest that stream biota relying mainly on dietary inputs from the riparian zone will be partially insulated from the effects of water chemistry on Hg availability. This has implications for the development of a whole-system understanding of nutrient and material cycling in streams, the choice of taxa in contaminant monitoring studies, and in understanding the fate of Hg in stream food webs.

  8. Towards Mechanistic Understanding of Mercury Availability and Toxicity to Aquatic Primary Producers.

    PubMed

    Dranguet, Perrine; Flück, Rebecca; Regier, Nicole; Cosio, Claudia; Le Faucheur, Séverine; Slaveykova, Vera I

    2014-11-01

    The present article reviews current knowledge and recent progress on the bioavailability and toxicity of mercury to aquatic primary producers. Mercury is a ubiquitous toxic trace element of global concern. At the base of the food web, primary producers are central for mercury incorporation into the food web. Here, the emphasis is on key, but still poorly understood, processes governing the interactions between mercury species and phytoplankton, and macrophytes, two representatives of primary producers. Mass transfer to biota surface, adsorption to cell wall, internalization and release from cells, as well as underlying toxicity mechanisms of both inorganic mercury and methylmercury are discussed critically. In addition, the intracellular distribution and transformation processes, their importance for mercury toxicity, species-sensitivity differences and trophic transfer are presented. The mini-review is illustrated with examples of our own research.

  9. Contamination of estuarine water, biota, and sediment by halogenated organic compounds: A field study

    USGS Publications Warehouse

    Pereira, W.E.; Rostad, C.E.; Chiou, C.T.; Brinton, T.I.; Barber, L.B.; Demcheck, D.K.; Demas, C.R.

    1988-01-01

    Studies conducted in the vicinity of an industrial outfall in the Calcasieu River estuary, Louisiana, have shown that water, bottom and suspended sediment, and four different species of biota are contaminated with halogenated organic compounds (HOC) including haloarenes. A "salting-out" effect in the estuary moderately enhanced the partitioning tendency of the contaminants into biota and sediments. Contaminant concentrations in water, suspended sediments, and biota were found to be far below the values predicted on the basis of the assumption of phase equilibria with respect to concentrations in bottom sediment. Relative concentration factors of HOC between biota (catfish) and bottom sediment increased with increasing octanol/estuarine water partition coefficients (Kow*), maximizing at log Kow* of about 5, although these ratios were considerably less than equilibrium values. In contrast, contaminant concentrations in water, biota, and suspended sediments were much closer to equilibrium values. Bioconcentration factors of HOC determined on the basis of lipid content for four different biotic species correlated reasonably well with equilibrium triolein/water partition coefficients (Ktw).

  10. Does nitrate co-pollution affect biological responses of an aquatic plant to two common herbicides?

    PubMed

    Nuttens, A; Chatellier, S; Devin, S; Guignard, C; Lenouvel, A; Gross, E M

    2016-08-01

    Aquatic systems in agricultural landscapes are subjected to multiple stressors, among them pesticide and nitrate run-off, but effects of both together have rarely been studied. We investigated possible stress-specific and interaction effects using the new OECD test organism, Myriophyllum spicatum, a widespread aquatic plant. In a fully factorial design, we used two widely applied herbicides, isoproturon and mesosulfuron-methyl, in concentration-response curves at two nitrate levels (219.63 and 878.52mg N-NO3). We applied different endpoints reflecting plant performance such as growth, pigment content, content in phenolic compounds, and plant stoichiometry. Relative growth rates based on length (RGR-L) were affected strongly by both herbicides, while effects on relative growth rate based on dry weight (RGR-DW) were apparent for isoproturon but hardly visible for mesosulfuron-methyl due to an increase in dry matter content. The higher nitrate level further reduced growth rates, specifically with mesosulfuron-methyl. Effects were visible between 50 and 500μgL(-1) for isoproturon and 0.5-5μgL(-1) for mesosulfuron-methyl, with some differences between endpoints. The two herbicides had opposite effects on chlorophyll, carotenoid and nitrogen contents in plants, with values increasing with increasing concentrations of isoproturon and decreasing for mesosulfuron-methyl. Herbicides and nitrate level exhibited distinct effects on the content in phenolic compounds, with higher nitrate levels reducing total phenolic compounds in controls and with isoproturon, but not with mesosulfuron-methyl. Increasing concentrations of mesosulfuron-methyl lead to a decline of total phenolic compounds, while isoproturon had little effect. Contents of carbon, nitrogen and phosphorus changed depending on the stressor combination. We observed higher phosphorus levels in plants exposed to certain concentrations of herbicides, potentially indicating a metabolic response. The C:N molar ratio

  11. Distribution of biota in a stream polluted by acid mine-drainage

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Warner, R.W.

    1971-01-01

    Acidic water draining from coal mines has severly restricted the diversity of biota inhabiting Roaring Creek, eastern West Virginia. Polluted reaches of the stream (median pH values ranging from 2.8 to 3.8) were inhabited by 3 to 12 genera of bottom-dwelling invertebrates and 10 to 19 species of periphytic algae. Invertebrates tolerant of the pollution included Sialis sp., chironomus plumosus and other Chironomidae, dytiscid beetles, and Ptilostomis sp. Predominant among the tolerant periphyton were Ulothrix tenerrima, Pinnularia termitina, Eunotia exigua, and Euglena mutabilis. Six other species of algae were tolerant of the acid mine-pollution, but were never numerous. Sections ofmore » Roaring Creek not severely polluted by acid drainage (pH medians of 4.5 or higher) supported diverse communities of 25 or more kinds of benthic animals and 27 or more species of periphytic algae. These stream reaches were inhibited by blackflies, crayfish, mayflies, stoneflies, and many species of caddisflies; these forms did not inhabit the more acidic stream reaches. Because of the complex and varying chemical composition of the acid mine-drainage, and also because of possible physical influences, measurements of pH values in the stream seemed to provide the most reliable, as well as unique, index of the effects of acid mine-drainage on aquatic life.« less

  12. Biota: sediment partitioning of aluminium smelter related PAHs and pulp mill related diterpenes by intertidal clams at Kitimat, British Columbia.

    PubMed

    Yunker, Mark B; Lachmuth, Cara L; Cretney, Walter J; Fowler, Brian R; Dangerfield, Neil; White, Linda; Ross, Peter S

    2011-09-01

    industrial pulping processes are readily accumulated by the clams (BSAFs >500). Thus while most of the smelter associated PAHs in sediments may not be bioavailable to benthic organisms, the plant terpenes (including retene, totarol, ferruginol, manool, dehydroabietane and other plant terpenes that form the chemical defence mechanism of conifers) released by pulp mills are bioavailable and possess demonstrated toxic properties. The large scale release of plant terpenes by some of the many pulp mills located in British Columbia and elsewhere represents a largely undocumented risk to aquatic biota. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Freshwater Wetland Habitat Loss and Fragmentation: Implications for Aquatic Biodiversity Conservation

    NASA Astrophysics Data System (ADS)

    Wolaver, B. D.; Pierre, J. P.; Labay, B. J.; Ryberg, W. A.; Hibbits, T. J.; Prestridge, H. L.

    2015-12-01

    Anthropogenic land use changes have caused widespread wetland loss and fragmentation. This trend has important implications for aquatic biota conservation, including the semi-aquatic Western Chicken Turtle (Deirochelys reticularia miaria). This species inhabits seasonally inundated, ephemeral water bodies and adjacent uplands in the southeastern U.S. However, wetland conversion to agriculture and urbanization is thought to cause the species' decline, particularly in Texas, which includes the westernmost part of its range. Because the species moves only a few kilometers between wetlands, it particularly sensitive to habitat loss and fragmentation. Thus, as part of the only state-funded species research program, this study provides the U.S. Fish and Wildlife Service (FWS) with scientific data to determine if the species warrants protection under the Endangered Species Act (ESA). We use a species distribution model to map potentially suitable habitat for most of East Texas. We evaluate landscape-scale anthropogenic activities in this region which may be contributing to the species' decline. We identify areas of urbanization, agricultural expansion, forestry, and resulting wetland loss. We find that between 2001 and 2011 approximately 80 km2 of wetlands were lost in potentially suitable habitat, including the urbanizing Houston area. We use spatial geostatistics to quantify wetland habitat fragmentation. We also introduce the Habitat Alteration Index (HAI), which calculates total landscape alteration and mean probability of occurrence to identify high-quality habitat most at risk of recent anthropogenic alteration. Population surveys by biologists are targeting these areas and future management actions may focus on mitigating anthropogenic activities there. While this study focuses on D. r. miaria, this approach can evaluate wetland habitat of other aquatic organisms.

  14. Development of water quality criteria of ammonia for protecting aquatic life in freshwater using species sensitivity distribution method.

    PubMed

    Park, Tae-Jin; Lee, Jong-Hyeon; Lee, Myung-Sung; Park, Chang-Hee; Lee, Chang-Hoon; Moon, Seong-Dae; Chung, Jiwoong; Cui, Rongxue; An, Youn-Joo; Yeom, Dong-Hyuk; Lee, Soo-Hyung; Lee, Jae-Kwan; Zoh, Kyung-Duk

    2018-09-01

    Ammonia is deemed one of the most important pollutants in the freshwater environment because of its highly toxic nature and ubiquity in surface water. This study thus aims to derive the criteria for ammonia in freshwater to protect aquatic life because there are no water quality criteria for ammonia in Korea. Short-term lethal tests were conducted to perform the species sensitivity distribution (SSD) method. This method is widely used in ecological risk assessment to determine the chemical concentrations to protect aquatic species. Based on the species sensitivity distribution method using Korean indigenous aquatic biota, the hazardous concentration for 5% of biological species (HC 5 ) value calculated in this study was 44mg/L as total ammonia nitrogen (TAN). The value of the assessment factor was set at 2. Consequently, the criteria for ammonia were derived as 22mg/L at pH7 and 20°C. When the derived value was applied to the monitoring data nationwide, 0.51%, 0.09%, 0.18%, 0.20%, and 0.35% of the monitoring sites in Han River, Nakdong River, Geum River, Youngsan River, and lakes throughout the nation, respectively, exceeded this criteria. The Ministry of Environment in Korea has been considering introducing water quality standard of ammonia for protecting aquatic life. Therefore, our results can provide the basis for introducing the ammonia standard in Korea. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. A method to assess longitudinal riverine connectivity in tropical streams dominated by migratory biota

    USGS Publications Warehouse

    Crook, K.E.; Pringle, C.M.; Freeman, Mary C.

    2009-01-01

    1. One way in which dams affect ecosystem function is by altering the distribution and abundance of aquatic species. 2. Previous studies indicate that migratory shrimps have significant effects on ecosystem processes in Puerto Rican streams, but are vulnerable to impediments to upstream or downstream passage, such as dams and associated water intakes where stream water is withdrawn for human water supplies. Ecological effects of dams and water withdrawals from streams depend on spatial context and temporal variability of flow in relation to the amount of water withdrawn. 3. This paper presents a conceptual model for estimating the probability that an individual shrimp is able to migrate from a stream's headwaters to the estuary as a larva, and then return to the headwaters as a juvenile, given a set of dams and water withdrawals in the stream network. The model is applied to flow and withdrawal data for a set of dams and water withdrawals in the Caribbean National Forest (CNF) in Puerto Rico. 4. The index of longitudinal riverine connectivity (ILRC), is used to classify 17 water intakes in streams draining the CNF as having low, moderate, or high connectivity in terms of shrimp migration in both directions. An in-depth comparison of two streams showed that the stream characterized by higher water withdrawal had low connectivity, even during wet periods. Severity of effects is illustrated by a drought year, where the most downstream intake caused 100% larval shrimp mortality 78% of the year. 5. The ranking system provided by the index can be used as a tool for conservation ecologists and water resource managers to evaluate the relative vulnerability of migratory biota in streams, across different scales (reach-network), to seasonally low flows and extended drought. This information can be used to help evaluate the environmental tradeoffs of future water withdrawals. ?? 2008 John Wiley & Sons, Ltd.

  16. High-precision 40Ar/39Ar age for the Jehol Biota

    NASA Astrophysics Data System (ADS)

    Chang, S.; Zhang, H.; Renne, P. R.; Fang, Y.

    2008-12-01

    Abundant fossils of the terrestrial Jehol Biota, including plants, insects, dinosaurs, birds, mammals and freshwater invertebrates, were discovered from the Yixian Formation and the overlying Jiufotang Formation in Inner Mongolia, Hebei Province and Liaoning Province, northeastern China. Because of the exceptional preservation of fossils, the Jehol Biota is one of the most important Mesozoic fossil outcrops and referred to as a "Mesozoic Pompeii". The Jehol Biota has provided a rare opportunity to address questions about the origin of birds, the evolution of feathers and flight, the early diversification of angiosperms and the timing of the radiation of placental mammals. The Tuchengzi Formation, which lies unconformably just below the Yixian Formation and consists mainly of variegated sandstones, is less fossiliferous than the two overlying formations. However, dinosaur tracks, silicified wood and compressed plants are found in this formation. A systematic 40Ar/39Ar dating of the Yixian and the Jiufotang formations was undertaken to provide a framework for understanding the timing and duration of the Jehol Biota and evolutionary events represented within it. Furthermore, determining the absolute age of the Tuchengzi Formation provides information to interpret abundant dinosaur tracks within and provide better age constrains for the beginning of the Jehol Biota. Here we present robust high-precision 40Ar/39Ar data for six tuff samples and two basalt samples collected from the Tuchengzi, the Yixian and the Jiufotang formations near the classic outcrops in western Liaoning, NE China. We obtain an age of 139.5 ± 1.0 Ma for the uppermost Tuchengzi Formation, an age of 129.7 ± 0.5 Ma for a basaltic lava from the bottom of the Yixian Formation and an age of 122.1 ± 0.3 Ma for a tuff from the base of the overlying Jiufotang Formation. Our data indicate that the Yixian Formation was deposited during the Early Cretaceous, the Barremian to early Aptian, within a time span

  17. Hydro-climatic Changes: Potential Non-linear Responses of Phosphorus Dynamic in Aquatic/Semi-aquatic Systems

    NASA Astrophysics Data System (ADS)

    Pant, H. K.

    2007-12-01

    Depending on resilience, threshold and lag times, hydro-climatic changes can cause nonlinear and/or irreversible changes in phosphorus (P) dynamic, and instigate P enrichment in aquatic/semi-aquatic systems. Thus, studying direct/indirect effects of expected global climate change on bioavailability of organic P in aquatic systems are in critical need, to help manage or increase the resilience of the ecosystem. The central hypothesis of this study is that P dynamic in aquatic, especially freshwater, ecosystem is likely to behave nonlinearly due to expected changes in sediment and water acidity, redox status, etc., because of potential hydro-climatic changes in the decades to come, thus, could face irreversible adverse changes. Devising possible biological and chemical treatments for the removal of P from eutrophic lakes, estuaries, etc, as well as helping in predicting the movement and fate of P under changing hydro-climatic conditions would be crucial to manage aquatic ecosystem in the near future. The critical question is not how much P is stored in any given aquatic/semi-aquatic system, but how the resilience and nonlinearity relate to the stability of stored P are affected due to the levels of environmental stressors, which are expected to fluctuate due to global change in the decades to come. Studies related to 31P Nuclear Magnetic Resonance Spectroscopy analysis, and multiple hydraulic retention cycles showed that, in general, frequent drying and reflooding of a semi-aquatic system such as wetland could significantly increase the bioavailability of P due to degradation of relatively less stable organic P, e.g., glycerophosphate and nucleoside monophosphate. Moreover, nutrients flux from sediments to the water column depended on the concentration gradients of the sediment-water interface and redox status. Shift in equilibrium P concentration of the water column as the water level rises, may cause release of adsorbed P from the sediments. Restoration of a

  18. The role of the geophysical template and environmental regimes in controlling stream-living trout populations

    Treesearch

    Brooke E. Penaluna; Steve F. Railsback; Jason B. Dunham; Sherri Johnson; Robert E. Bilby; Arne E. Skaugset; Michael Bradford

    2015-01-01

    The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the geophysical template versus...

  19. Surface-water-quality assessment of the Yakima River basin in Washington: major-and minor-element data for sediment, water, and aquatic biota, 1987-91

    USGS Publications Warehouse

    Fuhrer, Gregory J.; Fluter, Shelley L.; McKenzie, Stuart W.; Rinella, Joseph F.; Crawford, J. Kent; Cain, Daniel J.; Hornberger, Michelle I.; Bridges, Jennifer L.; Skach, Kenneth A.

    1994-01-01

    Streambed-sediment samples were collected once from 27 sites in the basin during 1987-91. Suspended-sediment and filtered-water samples were collected monthly and during hydrologic events (including snowmelt and winter rainstorms) at seven sites, and filtered-water samples were collected at least once at an additional 37 sites during synoptic samplings. Unfiltered-water samples were collected at seven sites on a quarterly basis during 1987 only. Samples of aquatic plants were collected once in 1989, and aquatic insects, fish, and clams were collected from 34 sites three times during 1989-90.

  20. Bioaccumulation factor of 137Cs in some marine biotas from West Bangka Indonesia

    NASA Astrophysics Data System (ADS)

    Suseno, Heny

    2014-03-01

    Radionuclides may be released from nuclear facilities to the marine environment. Concentrations of radionuclides within marine biotic systems can be influenced by a number of factors, including the type of biota, its source, the radionuclide, and specific characteristics of the sampled specimens and the marine environment (salinity, etc.). The bioconcentration factor for a marine organism is the ratio of the concentration of a radionuclide in that organism to the concentration found in its marine water environment - under conditions of equilibrium. Information on the bioaccumulation of Cs-137 in marine organisms is required to risk assessment evaluates the potential risks to human health. Bioaccumulation of Cs was investigated in marine biota from west Bangka such as Marine cat fish (Arius thalassinus), Baramundi (Lates calcarifer), Mackerel (Scomberomorus commerson), Striped eel catfish (Plotosus lineatus), eel tailed fish (Euristhmus microceps), Yellowtail fusilier (Caesio erythrogaster), Coastal crab (Scylla sp), White shrimp (Penaeus merguiensis) and marine bivalve mollusk (Anadara granosa). Muscle of these marine biota, sediments and water were assayed for Cs-137 by HPGe gamma spectrometer. The bioaccumulation factor for fishes were calculated by ratio of concentration Cs-137 in muscle biota to the its concentration in water. The bioaccumulation factor for mollusks were calculates by ratio of concentration Cs-137 in muscle biota to the its concentration in sediments. The bioaccumulation factor were range 4.99 to 136.34.

  1. Lead (Pb) in biota and perceptions of Pb exposure at a recently designated Superfund beach site in New Jersey.

    PubMed

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

    2012-01-01

    The Raritan Bay Slag Site (New Jersey) was designated a Superfund site in 2009 because the seawall, jetties, and sediment contained lead (Pb). Our objective was to compare Pb and mercury (Hg) levels in biota and public perceptions of exposure at the Superfund and reference sites. Samples (algae, invertebrates, fish) were collected from the Raritan Bay Slag Site and reference sites and analyzed for Pb and Hg. Waterfront users were interviewed using a standard questionnaire. Levels of Pb in aquatic organisms were compared to ecological and human health safety standards. Lead levels were related to location, trophic level, and mobility. Lead levels in biota were highest at the western side of the West Jetty. Mean Pb levels were highest for algae (Fucus = 53,600 ± 6990 ng/g = ppb [wet weight], Ulva = 23,900 ± 2430 ppb), intermediate for grass shrimp (7270 ± 1300 ppb, 11,600 ± 3340 ppb), and lowest for fish (Atlantic silversides 218 ± 44 ppb). Within species, Pb levels varied significantly across the sampling sites. Lead levels in algae, sometimes ingested by individuals, were sufficiently high to exceed human safety levels. Mercury levels did not differ between the Superfund and reference sites. Despite the fence and warnings, people (1) used the Superfund and reference sites similarly, (2) had similar fish consumption rates, and (3) were not concerned about Pb, although most individuals knew the metal was present. The fish sampled posed no apparent risk for human consumers, but the algae did.

  2. LEAD (Pb) IN BIOTA AND PERCEPTIONS OF Pb EXPOSURE AT A RECENTLY DESIGNATED SUPERFUND BEACH SITE IN NEW JERSEY

    PubMed Central

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

    2014-01-01

    The Raritan Bay Slag Site (New Jersey) was designated a Superfund site in 2009 because the seawall, jetties, and sediment contained lead (Pb). Our objective was to compare Pb and mercury (Hg) levels in biota and public perceptions of exposure at the Superfund and reference sites. Samples (algae, invertebrates, fish) were collected from the Raritan Bay Slag Site and reference sites and analyzed for Pb and Hg. Waterfront users were interviewed using a standard questionnaire. Levels of Pb in aquatic organisms were compared to ecological and human health safety standards. Lead levels were related to location, trophic level, and mobility. Lead levels in biota were highest at the western side of the West Jetty. Mean Pb levels were highest for algae (Fucus = 53,600 ± 6990 ng/g = ppb [wet weight], Ulva = 23,900 ± 2430 ppb), intermediate for grass shrimp (7270 ± 1300 ppb, 11,600 ± 3340 ppb), and lowest for fish (Atlantic silversides 218 ± 44 ppb). Within species, Pb levels varied significantly across the sampling sites. Lead levels in algae, sometimes ingested by individuals, were sufficiently high to exceed human safety levels. Mercury levels did not differ between the Superfund and reference sites. Despite the fence and warnings, people (1) used the Superfund and reference sites similarly, (2) had similar fish consumption rates, and (3) were not concerned about Pb, although most individuals knew the metal was present. The fish sampled posed no apparent risk for human consumers, but the algae did. PMID:22409490

  3. Natural origin arsenic in aquatic organisms from a deep oligotrophic lake under the influence of volcanic eruptions.

    PubMed

    Juncos, Romina; Arcagni, Marina; Rizzo, Andrea; Campbell, Linda; Arribére, María; Guevara, Sergio Ribeiro

    2016-02-01

    Volcanic eruptions are recognized sources of toxic elements to freshwater, including arsenic (As). In order to study the short term changes in the bioaccumulation of naturally occurring As by aquatic organisms in Lake Nahuel Huapi (Argentina), located close to the Puyehue-Cordón Caulle volcanic complex (PCCVC), we described As concentrations at different trophic levels and food web transfer patterns in three sites of the lake prior to the last PCCVC eruption (June 2011), and compared As concentrations in biota before and after the eruption. The highest As concentrations and greater variations both between sites and position in the water column, were observed in phytoplankton (3.9-64.8 µg g(-1) dry weight, DW) and small zooplankton (4.3-22.3 µg g(-1) DW). The pattern of As accumulation in aquatic organisms (whole body or muscle) was: primary producers (phytoplankton) > scrapper mollusks (9.3-15.3 µg g(-1) DW) > filter feeding mollusks (5.4-15.6 µg g(-1) DW) > omnivorous invertebrates (0.4-9.2 µg g(-1) DW) > zooplankton (1.2-3.5 µg g(-1) DW) > fish (0.2-1.9 µg g(-1) DW). We observed As biodilution in the whole food web, and in salmonids food chains, feeding on fish prey; but biomagnification in the food chain of creole perch, feeding on benthic crayfish. The impact of the 2011 PCCVC eruption on the As levels of biota was more evident in pelagic-associated organisms (zooplankton and planktivorous fish), but only in the short term, suggesting a brief high bioavailability of As in water after ash deposition. In benthic organisms As variations likely responded to shift in diet due to coverage of the littoral zone with ashes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Effect of Culverts on Predator-Prey Interactions in a Tropical Stream.

    NASA Astrophysics Data System (ADS)

    Hein, C. L.; Kikkert, D. A.; Crowl, T. A.

    2005-05-01

    As part of a biocomplexity project in Puerto Rico, we use river and road networks as a platform to understand the interactions between stream biota, the physical environment, and human activity. Specifically, we ask if humans affect aquatic organisms through road building and recreational activities. Culverts have been documented to impede or slow migration of aquatic biota. This is especially important in these streams because all of the freshwater, stream species have diadramous life cycles. If culverts do act as bottlenecks to shrimp migrations, we expect altered predator-prey interactions downstream through density-dependent predation dynamics. In order to determine how roads may affect predation rates on upstream migrating shrimp, we parameterized functional response curves for mountain mullet (Agonostomus monticola) consuming shrimp (Xiphocaris sp.) using artificial mesocosm experiments. We then used data obtained from underwater videography to determine how culverts decrease the rate and number of shrimp moving upstream. These data were combined in a predator-prey model to quantify the effects of culverts on localized shrimp densities and fish predation.

  5. Sunlight affects aggregation and deposition of graphene oxide in the aquatic environment.

    EPA Science Inventory

    In this study, we investigate the role of simulated sunlight on the physicochemical properties, aggregation, and deposition of graphene oxide (GO) in aquatic environments. Results show that light exposure under varied environmental conditions significantly impacts the physicochem...

  6. Linking fish tolerance to water quality criteria for the assessment of environmental flows: A practical method for streamflow regulation and pollution control.

    PubMed

    Zhao, Changsen; Yang, Shengtian; Liu, Junguo; Liu, Changming; Hao, Fanghua; Wang, Zhonggen; Zhang, Huitong; Song, Jinxi; Mitrovic, Simon M; Lim, Richard P

    2018-05-15

    The survival of aquatic biota in stream ecosystems depends on both water quantity and quality, and is particularly susceptible to degraded water quality in regulated rivers. Maintenance of environmental flows (e-flows) for aquatic biota with optimum water quantity and quality is essential for sustainable ecosystem services, especially in developing regions with insufficient stream monitoring of hydrology, water quality and aquatic biota. Few e-flow methods are available that closely link aquatic biota tolerances to pollutant concentrations in a simple and practical manner. In this paper a new method was proposed to assess e-flows that aimed to satisfy the requirements of aquatic biota for both the quantity and quality of the streamflow by linking fish tolerances to water quality criteria, or the allowable concentration of pollutants. For better operation of water projects and control of pollutants discharged into streams, this paper presented two coefficients for streamflow adjustment and pollutant control. Assessment of e-flows in the Wei River, the largest tributary of the Yellow River, shows that streamflow in dry seasons failed to meet e-flow requirements. Pollutant influx exerted a large pressure on the aquatic ecosystem, with pollutant concentrations much higher than that of the fish tolerance thresholds. We found that both flow velocity and water temperature exerted great influences on the pollutant degradation rate. Flow velocity had a much greater influence on pollutant degradation than did the standard deviation of flow velocity. This study provides new methods to closely link the tolerance of aquatic biota to water quality criteria for e-flow assessment. The recommended coefficients for streamflow adjustment and pollutant control, to dynamically regulate streamflow and control pollutant discharge, are helpful for river management and ecosystems rehabilitation. The relatively low data requirement also makes the method easy to use efficiently in developing

  7. Hazard identification and risk characterization of bisphenols A, F and AF to aquatic organisms.

    PubMed

    Tišler, Tatjana; Krel, Alja; Gerželj, Urška; Erjavec, Boštjan; Dolenc, Marija Sollner; Pintar, Albin

    2016-05-01

    Production of bisphenol A (BPA) analogues such as bisphenol F (BPF) and bisphenol AF (BPAF) has recently increased, due to clear evidence of adverse effects of BPA on humans and wildlife. Bisphenols (BPs) have already been released into aquatic environment without previous available information about potential adverse effects of BPs and their potential risk to aquatic ecosystems. In this study, lethal and sublethal effects of BPF and BPAF to bacteria, algae, crustacea and fish embryos were investigated and the results were compared to the adverse effects obtained for BPA. We found that BPAF was the most toxic compound to Daphnia magna, Danio rerio and Desmodesmus subspicatus; the lowest 72 h EC50 (median effective concentration) and 21 d NOEC (no observed effect concentration) values were determined at 2.2 mg/L regarding zebrafish hatching success and 0.23 mg/L of BPAF obtained for growth and reproduction of water fleas, respectively. In most cases, BPA was more toxic to D. magna, D. rerio and D. subspicatus in comparison to BPF, but pigmentation of zebrafish embryos after 48 h of exposure and reproduction of water fleas after 21-day D. magna reproductive test exposure to BPF were much more impaired. Risk quotients (measured environmental concentration/21 d NOEC) showed that BPA, BPF and BPAF are recently not chronically hazardous to the survival, reproduction and growth of water fleas in surface waters. On the other hand, we importantly show that currently present BPAF concentrations in surface waters could cause a potential ecological risk to aquatic organisms. In the near future, higher concentrations of BPF and BPAF in surface waters are anticipated and for this reason further testing using test systems with various aquatic species and endpoints are needed to provide additional information about toxic impacts of BPF and BPAF on aquatic biota. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Persistence of spilled oil on shores and its effects on biota

    USGS Publications Warehouse

    Irvine, G.V.; ,

    2000-01-01

    Over two million tonnes of oil are estimated to enter the world's oceans every year. A small percentage, but still a large volume, of this oil strands onshore, where its persistence is governed primarily by the action of physical forces. In some cases, biota influence the persistence of stranded oil or the rate of its weathering. Oil's deleterious effects on biota are frequently related to the persistence and degree of weathering of the oil, with long-lasting effects in low-energy environments such as salt marshes and coastal mangroves, or in higher-energy environments where oil is sequestered. However, an oil spill can have disproportionately large biological effects when it affects key species or processes (e.g., structurally important species, predators, prey, recruitment, or succession). In these cases, the continuing presence of oil is not always a prerequisite for continuing biological effects. There are relatively few long-term studies of the effects of oil spills; data from these suggest that oil can persist for decades in some environments or situations, and that biological effects can be equally persistent. Broad-based, integrated studies have been the most revealing in terms of the importance of direct and indirect effects, spillover effects between different parts of the environment, and continuing linkages between residual oil and biologic effects. Clean-up and treatment techniques applied to spilled or stranded oil can also have significant, long-lasting effects and need to be carefully evaluated prior to use.

  9. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the lower-Colorado River valley, Arizona, California, and Nevada

    USGS Publications Warehouse

    Radtke, D.B.; Kepner, W.G.; Effertz, R.J.

    1988-01-01

    The Lower Colorado River Valley Irrigation Drainage Project area included the Colorado River and its environs from Davis Dam to just above Imperial Dam. Water, bottom sediment, and biota were sampled at selected locations within the study area and analyzed for selected inorganic and synthetic organic constituents that are likely to be present at toxic concentrations. With the exceptions of selenium and DDE, this study found sampling locations to be relatively free of large concentrations of toxic constituents that could be a threat to humans, fish, and wildlife. Selenium was the only inorganic constituent to exceed any existing standard, criterion, or guideline for protection of fish and wildlife resources. Concentrations of DDE in double-crested cormorants, however, exceeded the criterion of 1.0 microgram per gram established by the National Academy of Sciences and the National Academy of Engineering for DDT and its metabolites for protection of wildlife. Dissolved-selenium concentrations in water from the lower Colorado River appear to be derived from sources above Davis Dam. At this time, therefore , agricultural practices in the lower Colorado River valley do not appear to exacerbate selenium concentrations. This fact, however, does not mean that the aquatic organisms and their predators are not in jeopardy. Continued selenium loading to the lower Colorado environment could severely affect important components of the ecosystem. (Author 's abstract)

  10. Multiple aquatic invasions by an endemic, terrestrial Hawaiian moth radiation

    PubMed Central

    Rubinoff, Daniel; Schmitz, Patrick

    2010-01-01

    Insects are the most diverse form of life on the planet, dominating both terrestrial and freshwater ecosystems, yet no species has a life stage able to breath, feed, and develop either continually submerged or without access to water. Such truly amphibious insects are unrecorded. In mountain streams across the Hawaiian Islands, some caterpillars in the endemic moth genus Hyposmocoma are truly amphibious. These larvae can breathe and feed indefinitely both above and below the water's surface and can mature completely submerged or dry. Remarkably, a molecular phylogeny based on 2,243 bp from both nuclear (elongation factor 1α and carbomoylphosphate synthase) and mitochondrial (cytochrome oxidase I) genes representing 216 individuals and 89 species of Hyposmocoma reveals that this amphibious lifestyle is an example of parallel evolution and has arisen from strictly terrestrial clades at least three separate times in the genus starting more than 6 million years ago, before the current high islands existed. No other terrestrial genus of animals has sponsored so many independent aquatic invasions, and no other insects are able to remain active indefinitely above and below water. Why and how Hyposmocoma, an overwhelmingly terrestrial group, repeatedly evolved unprecedented aquatic species is unclear, although there are many other evolutionary anomalies across the Hawaiian archipelago. The uniqueness of the community assemblages of Hawaii's isolated biota is likely critical in generating such evolutionary novelty because this amphibious ecology is unknown anywhere else. PMID:20308549

  11. Extinction risk of soil biota

    PubMed Central

    Veresoglou, Stavros D.; Halley, John M.; Rillig, Matthias C.

    2015-01-01

    No species lives on earth forever. Knowing when and why species go extinct is crucial for a complete understanding of the consequences of anthropogenic activity, and its impact on ecosystem functioning. Even though soil biota play a key role in maintaining the functioning of ecosystems, the vast majority of existing studies focus on aboveground organisms. Many questions about the fate of belowground organisms remain open, so the combined effort of theorists and applied ecologists is needed in the ongoing development of soil extinction ecology. PMID:26593272

  12. Chesapeake Bay Low Freshwater Inflow Study. Phase II. MAP FOLIO. Biota Assessment.

    DTIC Science & Technology

    1982-05-01

    conditions. These were: 1) Base Average -- average freshwater inflow conditions. by increased water consumption projected for the year 2020. 3) Base Drought...RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS. 1963- A TAI m - ii J May 1982 Chesapeake Bay Low Freshwater Inflow Study Phase II Biota Assessment Map...A PERIOD ZOVERED change was found to CIESAPEAKE BAY LOW FRESHWATER INFLOW STUDY FINAL BIOTA ASSESSMENT PHASE II: FINAL REPORT MAP FOLIO s PERFORMING

  13. The effect of chronic silver nanoparticles on aquatic system in microcosms.

    PubMed

    Jiang, Hong Sheng; Yin, Liyan; Ren, Na Na; Xian, Ling; Zhao, Suting; Li, Wei; Gontero, Brigitte

    2017-04-01

    Silver nanoparticles (AgNPs) inevitably discharge into aquatic environments due to their abundant use in antibacterial products. It was reported that in laboratory conditions, AgNPs display dose-dependent toxicity to aquatic organisms, such as bacteria, algae, macrophytes, snails and fishes. However, AgNPs could behave differently in natural complex environments. In the present study, a series of microcosms were established to investigate the distribution and toxicity of AgNPs at approximately 500 μg L -1 in aquatic systems. As a comparison, the distribution and toxicity of the same concentration of AgNO 3 were also determined. The results showed that the surface layer of sediment was the main sink of Ag element for both AgNPs and AgNO 3 . Both aquatic plant (Hydrilla verticillata) and animals (Gambusia affinis and Radix spp) significantly accumulated Ag. With short-term treatment, phytoplankton biomass was affected by AgNO 3 but not by AgNPs. Chlorophyll content of H. verticillata increased with both AgNPs and AgNO 3 short-term exposure. However, the biomass of phytoplankton, aquatic plant and animals was not significantly different between control and samples treated with AgNPs or AgNO 3 for 90 d. The communities, diversity and richness of microbes were not significantly affected by AgNPs and AgNO 3 ; in contrast, the nitrification rate and its related microbe (Nitrospira) abundance significantly decreased. AgNPs and AgNO 3 may affect the nitrogen cycle and affect the environment and, since they might be also transferred to food web, they represent a risk for health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Preservation of Early Cambrian animals of the Chengjiang biota

    NASA Astrophysics Data System (ADS)

    Gabbott, Sarah E.; Xian-Guang, Hou; Norry, Michael J.; Siveter, David J.

    2004-10-01

    The Chengjiang biota of Yunnan, China, documents the earliest extensive radiation of the Metazoa recorded in the fossil record. Gauging preservational bias is crucial in providing an assessment of the completeness of this biota and thereby elucidating whether it represents a comprehensive depiction of Early Cambrian life. We here present a model to explain the nature of the exceptional preservation of the Chengjiang biota and details of the decay process. This study indicates that Chengjiang fossils were preserved through two taphonomic pathways that may have captured tissues of distinct compositions, and this finding should provide a foundation for the interpretation of Chengjiang fossils. Many Chengjiang fossils are preserved by pyrite (later pseudomorphed by iron oxides); the clay-rich host sediment was deficient in organic carbon but replete in available Fe, and this composition ensured that a decaying carcass acted as a local substrate for Fe- and S-reducing bacteria. Pyrite morphology probably reflects contrasts in the decay rate, and hence the H2S production rate, of different tissues in a carcass. Reactive, rapidly decaying tissues would have quickly supplied H2S, producing many pyrite nuclei, resulting in framboidal habits. More recalcitrant tissues would have produced H2S more slowly, so that crystal growth operated on fewer nuclei, resulting in larger euhedral pyrite crystals. Reflective films, especially common on Chengjiang arthropods, represent the remains of degraded carbon.

  15. A synthesis of aquatic science for management of Lakes Mead and Mohave

    USGS Publications Warehouse

    Rosen, Michael R.; Turner, Kent; Goodbred, Steven L.; Miller, Jennell M.

    2012-01-01

    Lakes Mead and Mohave, which are the centerpieces of Lake Mead National Recreation Area, provide many significant benefits that have made the modern development of the Southwestern United States possible. Lake Mead is the largest reservoir by volume in the nation and it supplies critical storage of water supplies for more than 25 million people in three Western States (California, Arizona, and Nevada). Storage within Lake Mead supplies drinking water and the hydropower to provide electricity for major cities including Las Vegas, Phoenix, Los Angeles, Tucson, and San Diego, and irrigation of more than 2.5 million acres of croplands. Lake Mead is arguably the most important reservoir in the nation because of its size and the services it delivers to the Western United States. This Circular includes seven chapters. Chapter 1 provides a short summary of the overall findings and management implications for Lakes Mead and Mohave that can be used to guide the reader through the rest of the Circular. Chapter 2 introduces the environmental setting and characteristics of Lakes Mead and Mohave and provides a brief management context of the lakes within the Colorado River system as well as overviews of the geological bedrock and sediment accumulations of the lakes. Chapter 3 contains summaries of the operational and hydrologic characteristics of Lakes Mead and Mohave. Chapter 4 provides information on water quality, including discussion on the monitoring of contaminants and sediments within the reservoirs. Chapter 5 describes aquatic biota and wildlife, including food-web dynamics, plankton, invertebrates, fish, aquatic birds, and aquatic vegetation. Chapter 6 outlines threats and stressors to the health of Lake Mead aquatic ecosystems that include a range of environmental contaminants, invasive species, and climate change. Chapter 7 provides a more detailed summary of overall findings that are presented in Chapter 1; and it contains a more detailed discussion on associated

  16. Analysis of marine sediment, water and biota for selected organic pollutants

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Murray, H.E.; Ray, L.E.; Giam, C.S.

    1981-12-01

    The concentrations of various organic pollutants (benzo(a)pyrene (BaP), hexachlorobenzene (HCB) and pentachlorophenol (PCP) were determined in samples of water, sediment and biota (flounder, killifish, shrimp, crabs, and squid) from San Luis Pass, Texas. Sediment was also analyzed for polychlorinated biphenyls (PCBs), phthalic acid esters (PAEs) and various pesticides. Only PCP was detectable in water. In sediment, the relative concentrations were PAEs >> BaP > (PCBs approx. HCB) > PCP. In biota, BaP was not detectable in any animal; HCB was highest in crabs and PCP was highest in all others (flounder, killifish, shrimp and squid). The relative concentrations of HCBmore » and PCP were different in the different organisms. The differences between the relative concentrations in the biota and in sediment are discussed. The results of this study are compared to values measured at other sites. This study is part of a larger effort to identify and quantitate pollutants in various Texas estuaries and to serve as a basis for monitoring marine pollution.« less

  17. A meta-analysis of responses of soil biota to global change.

    PubMed

    Blankinship, Joseph C; Niklaus, Pascal A; Hungate, Bruce A

    2011-03-01

    Global environmental changes are expected to impact the abundance of plants and animals aboveground, but comparably little is known about the responses of belowground organisms. Using meta-analysis, we synthesized results from over 75 manipulative experiments in order to test for patterns in the effects of elevated CO(2), warming, and altered precipitation on the abundance of soil biota related to taxonomy, body size, feeding habits, ecosystem type, local climate, treatment magnitude and duration, and greenhouse CO(2) enrichment. We found that the positive effect size of elevated CO(2) on the abundance of soil biota diminished with time, whereas the negative effect size of warming and positive effect size of precipitation intensified with time. Trophic group, body size, and experimental approaches best explained the responses of soil biota to elevated CO(2), whereas local climate and ecosystem type best explained responses to warming and altered precipitation. The abundance of microflora and microfauna, and particularly detritivores, increased with elevated CO(2), indicative of microbial C limitation under ambient CO(2). However, the effects of CO(2) were smaller in field studies than in greenhouse studies and were not significant for higher trophic levels. Effects of warming did not depend on taxon or body size, but reduced abundances were more likely to occur at the colder and drier sites. Precipitation limited all taxa and trophic groups, particularly in forest ecosystems. Our meta-analysis suggests that the responses of soil biota to global change are predictable and unique for each global change factor.

  18. Differential contribution of soil biota groups to plant litter decomposition as mediated by soil use

    PubMed Central

    Falco, Liliana B.; Sandler, Rosana V.; Coviella, Carlos E.

    2015-01-01

    Plant decomposition is dependant on the activity of the soil biota and its interactions with climate, soil properties, and plant residue inputs. This work assessed the roles of different groups of the soil biota on litter decomposition, and the way they are modulated by soil use. Litterbags of different mesh sizes for the selective exclusion of soil fauna by size (macro, meso, and microfauna) were filled with standardized dried leaves and placed on the same soil under different use intensities: naturalized grasslands, recent agriculture, and intensive agriculture fields. During five months, litterbags of each mesh size were collected once a month per system with five replicates. The remaining mass was measured and decomposition rates calculated. Differences were found for the different biota groups, and they were dependant on soil use. Within systems, the results show that in the naturalized grasslands, the macrofauna had the highest contribution to decomposition. In the recent agricultural system it was the combined activity of the macro- and mesofauna, and in the intensive agricultural use it was the mesofauna activity. These results underscore the relative importance and activity of the different groups of the edaphic biota and the effects of different soil uses on soil biota activity. PMID:25780777

  19. Selenium, selected inorganic elements, and organochlorine pesticides in bottom material and biota from the Colorado River delta

    USGS Publications Warehouse

    Garcia-Hernandez, J.; King, K.A.; Velasco, A.L.; Shumilin, E.; Mora, M.A.; Glenn, E.P.

    2001-01-01

    Concentrations of selenium (Se) in bottom material ranged from 0.6 to 5.0 μg g−1, and from 0.5 to 18.3 μg g−1in biota; 23% of samples exceeded the toxic threshold. Concentrations of DDE in biota exceeded the toxic threshold in 30% of the samples. Greater concentrations of selenium in biota were found at sites with strongly reducing conditions, no output, alternating periods of drying and flooding or dredging activities, and at sites that received water directly from the Colorado River. The smallest Se concentrations in biota were found at sites where an outflow and exposure or physical disturbance of the bottom material were uncommon.

  20. Leaf litter quality affects aquatic insect emergence: contrasting patterns from two foundation trees.

    PubMed

    Compson, Zacchaeus G; Adams, Kenneth J; Edwards, Joeseph A; Maestas, Jesse M; Whitham, Thomas G; Marks, Jane C

    2013-10-01

    Reciprocal subsidies between rivers and terrestrial habitats are common where terrestrial leaf litter provides energy to aquatic invertebrates while emerging aquatic insects provide energy to terrestrial predators (e.g., birds, lizards, spiders). We examined how aquatic insect emergence changed seasonally with litter from two foundation riparian trees, whose litter often dominates riparian streams of the southwestern United States: Fremont (Populus fremontii) and narrowleaf (Populus angustifolia) cottonwood. P. fremontii litter is fast-decomposing and lower in defensive phytochemicals (i.e., condensed tannins, lignin) relative to P. angustifolia. We experimentally manipulated leaf litter from these two species by placing them in leaf enclosures with emergence traps attached in order to determine how leaf type influenced insect emergence. Contrary to our initial predictions, we found that packs with slow-decomposing leaves tended to support more emergent insects relative to packs with fast-decomposing leaves. Three findings emerged. Firstly, abundance (number of emerging insects m(-2) day(-1)) was 25% higher on narrowleaf compared to Fremont leaves for the spring but did not differ in the fall, demonstrating that leaf quality from two dominant trees of the same genus yielded different emergence patterns and that these patterns changed seasonally. Secondly, functional feeding groups of emerging insects differed between treatments and seasons. Specifically, in the spring collector-gatherer abundance and biomass were higher on narrowleaf leaves, whereas collector-filterer abundance and biomass were higher on Fremont leaves. Shredder abundance and biomass were higher on narrowleaf leaves in the fall. Thirdly, diversity (Shannon's H') was higher on Fremont leaves in the spring, but no differences were found in the fall, showing that fast-decomposing leaves can support a more diverse, complex emergent insect assemblage during certain times of the year. Collectively, these

  1. Organophosphorus flame retardants and plasticizers in marine and fresh water biota and in human milk.

    PubMed

    Sundkvist, Anneli Marklund; Olofsson, Ulrika; Haglund, Peter

    2010-04-01

    The levels and relative proportions of 11 organophosphorus flame retardants and plasticizers (OPs), some of which are reportedly toxic to aquatic organisms, were investigated in human breast milk and samples of fish and mussels from Swedish lakes and coastal areas in order to assess spatial differences in environmental exposure and spatial and temporal differences in human exposure. Some of the biota samples were collected at locations with known potential sources of OPs, but most were collected in background locations. Tris-2-chloroisopropyl phosphate (TCPP) and triphenyl phosphate (TPP) dominated in the biota with levels ranging from 170 to 770 ng g(-1) for TCPP in perch and between 21 and 180 ng g(-1) for TPP. In milk samples, TCPP (median 45 ng g(-1)) and tributyl phosphate (median 12 ng g(-1)) were the most frequently occurring OPs. Among samples of fish from background locations, the concentrations and profiles of most OPs were quite similar, indicating that their sources were diffuse. However, in fish from sample locations near known sources, there were marked differences in OP concentrations and profiles. Fish from a stream receiving surface water from Arlanda airport displayed high levels of OPs (10 200 ng g(-1)) that are commonly used in aircraft hydraulic fluids. Fish collected at points 1 or 2 km downstream of sewage treatment plants showed significantly higher levels of tris(2-butoxyethyl) phosphate (TBEP), one of the most typically abundant OP in effluents from such plants. In the milk samples obtained from women in different towns no distinct differences were detected in OP concentrations or profiles. However, the levels of TBEP tended to be higher in milk collected 10 years ago than in milk collected more recently. However, human exposure to OPs through eating fish or to breastfeeding babies seems to be of minor importance in relation to other potential sources, such as indoor dust inhalation and ingestion.

  2. Affecting of aquatic vascular plant Lemna minor by cisplatin revealed by voltammetry.

    PubMed

    Supalkova, Veronika; Beklova, Miroslava; Baloun, Jiri; Singer, Christoph; Sures, Bernd; Adam, Vojtech; Huska, Dalibor; Pikula, Jiri; Rauscherova, Libuse; Havel, Ladislav; Zehnalek, Josef; Kizek, Rene

    2008-02-01

    Within the context of application of platinum derivates based effective cytostatics, we can suppose that these risk metals can get into aquatic ecosystems where they can show biologic availability for food chain. In the present work we report on investigation of affecting of duckweed (Lemna minor) by various doses of cisplatin (0, 5, 10, 20, 40, 80 and 160 microM) for 4 days. The toxic influence of cisplatin was evaluated on the basis of growth inhibition expressed as number of leaves, growth rate, and total amount of biomass. The result value of 96hEC50, calculated from growth inhibition with comparison of growth rates, was 6.93 microM. Moreover we aimed on determination of cisplatin content using differential pulse voltammetry. The highest content of cisplatin (320 ng g(-1) of fresh weight) was determined in plants treated by 80 microM at the second day of treatment. Plants protect themselves against heavy metals by means of synthesis of cysteine-rich peptides such as glutathione and phytochelatins. Thus thiol determination in the treated plants by means of Brdicka reaction followed. The marked increase in thiol concentration detected is associated with defence reaction of the plant against stress caused by cisplatin.

  3. Virginia flow-ecology modeling results—An initial assessment of flow reduction effects on aquatic biota

    USGS Publications Warehouse

    Rapp, Jennifer L.; Reilly, Pamela A.

    2017-11-14

    BackgroundThe U.S. Geological Survey (USGS), in cooperation with the Virginia Department of Environmental Quality (DEQ), reviewed a previously compiled set of linear regression models to assess their utility in defining the response of the aquatic biological community to streamflow depletion.As part of the 2012 Virginia Healthy Watersheds Initiative (HWI) study conducted by Tetra Tech, Inc., for the U.S. Environmental Protection Agency (EPA) and Virginia DEQ, a database with computed values of 72 hydrologic metrics, or indicators of hydrologic alteration (IHA), 37 fish metrics, and 64 benthic invertebrate metrics was compiled and quality assured. Hydrologic alteration was represented by simulation of streamflow record for a pre-water-withdrawal condition (baseline) without dams or developed land, compared to the simulated recent-flow condition (2008 withdrawal simulation) including dams and altered landscape to calculate a percent alteration of flow. Biological samples representing the existing populations represent a range of alteration in the biological community today.For this study, all 72 IHA metrics, which included more than 7,272 linear regression models, were considered. This extensive dataset provided the opportunity for hypothesis testing and prioritization of flow-ecology relations that have the potential to explain the effect(s) of hydrologic alteration on biological metrics in Virginia streams.

  4. Potential effects of coalbed natural gas development on fish and aquatic resources

    USGS Publications Warehouse

    Farag, Aïda M.; Harper, David D.; Senecal, Anna C.; Hubert, Arthur E.; Reddy, K.J.

    2010-01-01

    The purpose of this chapter is to provide a summary of issues and findings related to the potential effects of coalbed natural gas (CBNG) development on fish and other aquatic resources. We reviewed CBNG issues from across the United States and used the Powder River Basin of Wyoming as a case study to exemplify some pertinent issues. The quality of water produced during CBNG extraction is quite variable. High total dissolved solids in many CBNG produced waters are of concern relative to fish and other aquatic organisms. Untreated CBNG produced water has the potential to be toxic to fish and aquatic organisms. Of particular concern at some locations in the Powder River basin are elevated concentrations of sodium bicarbonate which have been shown to be toxic to some species of larval fish and aquatic invertebrates. The areas affected by direct toxicity were limited to headwaters and small tributaries studied in the basin. The potential effects of organic compounds used during well drilling and CBNG production on water quality, fish, and aquatic organisms are not well defined. Water produced from CBNG wells that is low in salts or has been treated to remove salts may be discharged into ephemeral or perennially-flowing streams. Higher flows in small streams can enhance erosion and affect habitat for fish and aquatic organisms. In Great Plains rivers, such as the Powder River, fish and aquatic invertebrate communities are structured by extreme environmental conditions. Direct discharge of CBNG produced water during periods of very low or no surface flow may cause shifts in the aquatic community structure. Additional effects of CBNG development on fish and aquatic organisms may stem from road building and pipeline construction, roads crossing streams and ephemeral water courses, the possible spread of invasive organisms, potential spills of toxic substances, and increased harvest of sport fish. 

  5. Selecting for extinction: nonrandom disease-associated extinction homogenizes amphibian biotas.

    PubMed

    Smith, Kevin G; Lips, Karen R; Chase, Jonathan M

    2009-10-01

    Studying the patterns in which local extinctions occur is critical to understanding how extinctions affect biodiversity at local, regional and global spatial scales. To understand the importance of patterns of extinction at a regional spatial scale, we use data from extirpations associated with a widespread pathogenic agent of amphibian decline, Batrachochytrium dendrobatidis (Bd) as a model system. We apply novel null model analyses to these data to determine whether recent extirpations associated with Bd have resulted in selective extinction and homogenization of diverse tropical American amphibian biotas. We find that Bd-associated extinctions in this region were nonrandom and disproportionately, but not exclusively, affected low-occupancy and endemic species, resulting in homogenization of the remnant amphibian fauna. The pattern of extirpations also resulted in phylogenetic homogenization at the family level and ecological homogenization of reproductive mode and habitat association. Additionally, many more species were extirpated from the region than would be expected if extirpations occurred randomly. Our results indicate that amphibian declines in this region are an extinction filter, reducing regional amphibian biodiversity to highly similar relict assemblages and ultimately causing amplified biodiversity loss at regional and global scales.

  6. Aquatic organism passage at road-stream crossings—synthesis and guidelines for effectiveness monitoring

    USGS Publications Warehouse

    Hoffman, Robert L.; Dunham, Jason B.; Hansen, Bruce P.

    2012-01-01

    Restoration and maintenance of passage for aquatic organisms at road-stream crossings represents a major management priority, involving an investment of hundreds of millions of dollars (for example, U.S. Government Accounting Office, 2001). In recent years, passage at hundreds of crossings has been restored, primarily by replacing barrier road culverts with bridges or stream simulation culverts designed to pass all species and all life stages of aquatic life and simulate natural hydro-geomorphic processes (U.S. Forest Service, 2008). The current situation has motivated two general questions: 1. Are current design standards for stream simulation culverts adequately re-establishing passage for aquatic biota? and 2. How do we monitor and evaluate effectiveness of passage restoration? To address the latter question, a national workshop was held in March 2010, in Portland, Oregon. The workshop included experts on aquatic organism passage from across the nation (see table of participants, APPENDIX) who addressed four classes of methods for monitoring effectiveness of aquatic organism passage—individual movement, occupancy, demography, and genetics. This report has been written, in part, for field biologists who will be undertaking and evaluating the effectiveness of aquatic organism passage restoration projects at road-stream crossings. The report outlines basic methods for evaluating road-stream crossing passage impairment and restoration and discusses under what circumstances and conditions each method will be useful; what questions each method can potentially answer; how to design and implement an evaluation study; and points out the fundamental reality that most evaluation projects will require special funding and partnerships among researchers and resource managers. The report is organized into the following sections, which can be read independently: 1. Historical context: In this section, we provide a brief history of events leading up to the present situation

  7. Bioaccumulation factors and the steady state assumption for cesium isotopes in aquatic foodwebs near nuclear facilities.

    PubMed

    Rowan, D J

    2013-07-01

    Steady state approaches, such as transfer coefficients or bioaccumulation factors, are commonly used to model the bioaccumulation of (137)Cs in aquatic foodwebs from routine operations and releases from nuclear generating stations and other nuclear facilities. Routine releases from nuclear generating stations and facilities, however, often consist of pulses as liquid waste is stored, analyzed to ensure regulatory compliance and then released. The effect of repeated pulse releases on the steady state assumption inherent in the bioaccumulation factor approach has not been evaluated. In this study, I examine the steady state assumption for aquatic biota by analyzing data for two cesium isotopes in the same biota, one isotope in steady state (stable (133)Cs) from geologic sources and the other released in pulses ((137)Cs) from reactor operations. I also compare (137)Cs bioaccumulation factors for similar upstream populations from the same system exposed solely to weapon test (137)Cs, and assumed to be in steady state. The steady state assumption appears to be valid for small organisms at lower trophic levels (zooplankton, rainbow smelt and 0+ yellow perch) but not for older and larger fish at higher trophic levels (walleye). Attempts to account for previous exposure and retention through a biokinetics approach had a similar effect on steady state, upstream and non-steady state, downstream populations of walleye, but were ineffective in explaining the more or less constant deviation between fish with steady state exposures and non-steady state exposures of about 2-fold for all age classes of walleye. These results suggest that for large, piscivorous fish, repeated exposure to short duration, pulse releases leads to much higher (137)Cs BAFs than expected from (133)Cs BAFs for the same fish or (137)Cs BAFs for similar populations in the same system not impacted by reactor releases. These results suggest that the steady state approach should be used with caution in any

  8. A simple biota removal algorithm for 35 GHz cloud radar measurements

    NASA Astrophysics Data System (ADS)

    Kalapureddy, Madhu Chandra R.; Sukanya, Patra; Das, Subrata K.; Deshpande, Sachin M.; Pandithurai, Govindan; Pazamany, Andrew L.; Ambuj K., Jha; Chakravarty, Kaustav; Kalekar, Prasad; Krishna Devisetty, Hari; Annam, Sreenivas

    2018-03-01

    Cloud radar reflectivity profiles can be an important measurement for the investigation of cloud vertical structure (CVS). However, extracting intended meteorological cloud content from the measurement often demands an effective technique or algorithm that can reduce error and observational uncertainties in the recorded data. In this work, a technique is proposed to identify and separate cloud and non-hydrometeor echoes using the radar Doppler spectral moments profile measurements. The point and volume target-based theoretical radar sensitivity curves are used for removing the receiver noise floor and identified radar echoes are scrutinized according to the signal decorrelation period. Here, it is hypothesized that cloud echoes are observed to be temporally more coherent and homogenous and have a longer correlation period than biota. That can be checked statistically using ˜ 4 s sliding mean and standard deviation value of reflectivity profiles. The above step helps in screen out clouds critically by filtering out the biota. The final important step strives for the retrieval of cloud height. The proposed algorithm potentially identifies cloud height solely through the systematic characterization of Z variability using the local atmospheric vertical structure knowledge besides to the theoretical, statistical and echo tracing tools. Thus, characterization of high-resolution cloud radar reflectivity profile measurements has been done with the theoretical echo sensitivity curves and observed echo statistics for the true cloud height tracking (TEST). TEST showed superior performance in screening out clouds and filtering out isolated insects. TEST constrained with polarimetric measurements was found to be more promising under high-density biota whereas TEST combined with linear depolarization ratio and spectral width perform potentially to filter out biota within the highly turbulent shallow cumulus clouds in the convective boundary layer (CBL). This TEST technique is

  9. Potential sources of 1,2,8,9-tetrachlorodibenzo-P-dioxin in the aquatic environment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wenning, R.J.; Harris, M.A.; Paustenbach, D.J.

    1992-04-01

    A recent study reported elevated levels of 1,2,8,9-tetrachlorodibenzo-p-dioxin (1,2,8,9-TCDD) in crustaceans and finfish collected from Newark Bay, New Jersey (Rappe et al., 1989). The authors suggested that the presence of this compound in biota was due to operations at a former 2,4,5-trichlorophenoxy acetic acid (2,4,5-T) manufacturing facility located on the lower Passaic River. Since 1,2,8,9-TCDD had been identified in two soil samples claimed to be associated with the site, it was concluded that the former manufacturing plant was the source of this compound. A review of the scientific literature was conducted to evaluate whether this isomer is associated with themore » formulation of 2,4,5-T and to determine whether 1,2,8,9-TCDD is commonly found in the aquatic environment. Measurements and chromatographic data from known sources of polychlorinated dibenzo-p-dioxins indicate that incinerator fly ash, soot from wood-burning chimneys, and the combustion of polychlorinated biphenyls and some chlorophenoxy herbicides are sources of 1,2,8,9-TCDD. This isomer has never been found in samples of 2,4,5-T. We conclude, therefore, that the presence of 1,2,8,9-TCDD in Newark Bay biota is not associated with 2,4,5-T manufacturers but, rather, the result of various commercial, residential, municipal, and industrial combustion processes.85 references.« less

  10. Global soil-climate-biome diagram: linking soil properties to climate and biota

    NASA Astrophysics Data System (ADS)

    Zhao, X.; Yang, Y.; Fang, J.

    2017-12-01

    As a critical component of the Earth system, soils interact strongly with both climate and biota and provide fundamental ecosystem services that maintain food, climate, and human security. Despite significant progress in digital soil mapping techniques and the rapidly growing quantity of observed soil information, quantitative linkages between soil properties, climate and biota at the global scale remain unclear. By compiling a large global soil database, we mapped seven major soil properties (bulk density [BD]; sand, silt and clay fractions; soil pH; soil organic carbon [SOC] density [SOCD]; and soil total nitrogen [STN] density [STND]) based on machine learning algorithms (regional random forest [RF] model) and quantitatively assessed the linkage between soil properties, climate and biota at the global scale. Our results demonstrated a global soil-climate-biome diagram, which improves our understanding of the strong correspondence between soils, climate and biomes. Soil pH decreased with greater mean annual precipitation (MAP) and lower mean annual temperature (MAT), and the critical MAP for the transition from alkaline to acidic soil pH decreased with decreasing MAT. Specifically, the critical MAP ranged from 400-500 mm when the MAT exceeded 10 °C but could decrease to 50-100 mm when the MAT was approximately 0 °C. SOCD and STND were tightly linked; both increased in accordance with lower MAT and higher MAP across terrestrial biomes. Global stocks of SOC and STN were estimated to be 788 ± 39.4 Pg (1015 g, or billion tons) and 63 ± 3.3 Pg in the upper 30-cm soil layer, respectively, but these values increased to 1654 ± 94.5 Pg and 133 ± 7.8 Pg in the upper 100-cm soil layer, respectively. These results reveal quantitative linkages between soil properties, climate and biota at the global scale, suggesting co-evolution of the soil, climate and biota under conditions of global environmental change.

  11. Metal toxicity differently affects the Iris pseudacorus-arbuscular mycorrhiza fungi symbiosis in terrestrial and semi-aquatic habitats.

    PubMed

    Wężowicz, K; Turnau, K; Anielska, T; Zhebrak, I; Gołuszka, K; Błaszkowski, J; Rozpądek, P

    2015-12-01

    Phytoremediation offers an environmental friendly alternative to conventional cleanup techniques. In this study, mycorrhizal fungi isolated from the roots of Mentha longifolia grown in the basin of the Centuria River (S Poland) were used. Iris pseudacorus was grown in substratum from an industrial waste, enriched in Pb, Fe, Zn, and Cd in a terrestrial and water-logged habitat. Plant yield and photosynthetic performance was the highest in the aquatic environment; however, the presence of toxic metals (TM) negatively affected photosystem II (PSII) photochemistry as shown by the JIP test. Fungi colonization and Cd accumulation within plant tissues was decreased. In the terrestrial habitat, neither arbuscular mycorrhizal fungi (AMF) nor metal toxicity affected plant growth, although metal uptake, Cd in particular, as well as photosynthesis were affected. Inoculated plants accumulated significantly more Cd, and photosynthesis was downregulated. The results presented in this study clearly indicate that the I. pseudacorus-AMF symbiosis adapts itself to the presence of toxic metals in the environment, optimizing resource supply, energy fluxes, and possibly stress tolerance mechanisms. Plant/AMF consortia grown in terrestrial and water-logged habitats utilize different strategies to cope with metal toxicity. The use of AMF in improving the phytoremediation potential of I. pseudacorus needs, however, further research.

  12. Soil biota reduce allelopathic effects of the invasive Eupatorium adenophorum.

    PubMed

    Zhu, Xunzhi; Zhang, Jintun; Ma, Keping

    2011-01-01

    Allelopathy has been hypothesized to play a role in exotic plant invasions, and study of this process can improve our understanding of how direct and indirect plant interactions influence plant community organization and ecosystem functioning. However, allelopathic effects can be highly conditional. For example allelopathic effects demonstrated in vivo can be difficult to demonstrate in field soils. Here we tested phytotoxicity of Eupatorium adenophorum (croftonweed), one of the most destructive exotic species in China, to a native plant species Brassica rapa both in sand and in native soil. Our results suggested that natural soils from different invaded habitats alleviated or eliminated the efficacy of potential allelochemicals relative to sand cultures. When that soil is sterilized, the allelopathic effects returned; suggesting that soil biota were responsible for the reduced phytotoxicity in natural soils. Neither of the two allelopathic compounds (9-Oxo-10,11-dehydroageraphorone and 9b-Hydroxyageraphorone) of E. adenophorum could be found in natural soils infested by the invader, and when those compounds were added to the soils as leachates, they showed substantial degradation after 24 hours in natural soils but not in sand. Our findings emphasize that soil biota can reduce the allelopathic effects of invaders on other plants, and therefore can reduce community invasibility. These results also suggest that soil biota may have stronger or weaker effects on allelopathic interactions depending on how allelochemicals are delivered.

  13. Soil Biota Reduce Allelopathic Effects of the Invasive Eupatorium adenophorum

    PubMed Central

    Zhu, Xunzhi; Zhang, Jintun; Ma, Keping

    2011-01-01

    Allelopathy has been hypothesized to play a role in exotic plant invasions, and study of this process can improve our understanding of how direct and indirect plant interactions influence plant community organization and ecosystem functioning. However, allelopathic effects can be highly conditional. For example allelopathic effects demonstrated in vivo can be difficult to demonstrate in field soils. Here we tested phytotoxicity of Eupatorium adenophorum (croftonweed), one of the most destructive exotic species in China, to a native plant species Brassica rapa both in sand and in native soil. Our results suggested that natural soils from different invaded habitats alleviated or eliminated the efficacy of potential allelochemicals relative to sand cultures. When that soil is sterilized, the allelopathic effects returned; suggesting that soil biota were responsible for the reduced phytotoxicity in natural soils. Neither of the two allelopathic compounds (9-Oxo-10,11-dehydroageraphorone and 9b-Hydroxyageraphorone) of E. adenophorum could be found in natural soils infested by the invader, and when those compounds were added to the soils as leachates, they showed substantial degradation after 24 hours in natural soils but not in sand. Our findings emphasize that soil biota can reduce the allelopathic effects of invaders on other plants, and therefore can reduce community invasibility. These results also suggest that soil biota may have stronger or weaker effects on allelopathic interactions depending on how allelochemicals are delivered. PMID:21980442

  14. Linking Resilience of Aquatic Species to Watershed Condition

    NASA Astrophysics Data System (ADS)

    Flitcroft, R. L.

    2017-12-01

    Watershed condition means different things to different people. From the perspective of aquatic ecology, watershed condition may be interpreted to mean the capacity of a watershed to support life history diversity of native species. Diversity in expression of life history is thought to confer resilience allowing portions of the broader population to survive stressful conditions. Different species have different life history strategies, many of which were developed through adaptation to regional or local environmental conditions and natural disturbance regimes. By reviewing adaptation strategies for species of interest at regional scales, characteristics of watersheds that confer resilience may be determined. Such assessments must be completed at multiple levels of spatial organization (i.e. sub-watershed, watershed, region) allowing assessments to be inferred across broad spatial extents. In a project on the Wenatchee River watershed, we guided models of wildfire effects on bull trout and spring Chinook from a meta-population perspective to determine risks to survival at local and population scales over multiple extents of spatial organization. In other work in the Oregon Coast Range, we found that historic landslides continue to exert habitat-forming pressure at local scales, leading to patchiness in distribution of habitats for different life stages of coho salmon. Further, climate change work in Oregon estuaries identified different vulnerabilities in terms of juvenile rearing habitat depending on the species of interest and the intensity of future changes in climate. All of these studies point to the importance of considering physical conditions in watersheds at multiple spatial extents from the perspective of native aquatic species in order to understand risks to long-term survival. The broader implications of watershed condition, from this perspective, is the determination of physical attributes that confer resilience to native biota. This may require

  15. Bioconcentration of TNT and RDX in coastal marine biota.

    PubMed

    Ballentine, Mark; Tobias, Craig; Vlahos, Penny; Smith, Richard; Cooper, Christopher

    2015-05-01

    The bioconcentration factor (BCF) was measured for 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in seven different marine species of varying trophic levels. Time series and concentration gradient treatments were used for water column and tissue concentrations of TNT, RDX, and their environmentally important derivatives 2-amino-4,6-dintrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT). BCF values ranged from 0.0031 to 484.5 mL g(-1) for TNT and 0.023 to 54.83 mL g(-1) for RDX. The use of log K ow value as an indicator was evaluated by adding marine data from this study to previously published data. For the munitions in this study, log K ow value was a good indicator in the marine environment. The initial uptake and elimination rates of TNT and RDX for Fucus vesiculosus were 1.79 and 0.24 h(-1) for TNT and 0.50 and 0.0035 h(-1) for RDX respectively. Biotransformation was observed in all biota for both TNT and RDX. Biotransformation of TNT favored 4-ADNT over 2-ADNT at ratios of 2:1 for F. vesiculosus and 3:1 for Mytilus edulis. Although RDX derivatives were measureable, the ratios of RDX derivatives were variable with no detectable trend. Previous approaches for measuring BCF in freshwater systems compare favorably with these experiments with marine biota, yet significant gaps on the ultimate fate of munitions within the biota exist that may be overcome with the use stable isotope-labeled munitions substrates.

  16. A dietary assessment of selenium risk to aquatic birds on a coal mine affected stream in Alberta, Canada

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wayland, M.; Casey, R.; Woodsworth, E.

    In this article, we present the results of a dietary-based assessment of the risk that selenium may pose to two aquatic bird species, the American Dipper (Cinclus mexicanus) and the Harlequin Duck (Histrionicus histrionicus), on one of the coal mine-affected streams, the Gregg River. The study consisted of (1) a literature-based toxicity assessment, (2) simulation of selenium exposure in the diets and eggs of the two species, and (3) a risk assessment that coupled information on toxicity and exposure. Diet and egg selenium concentrations associated with a 20% hatch failure rate were 6.4 and 17 {mu} g {center_dot} g{sup -1}more » dry wt, respectively. Simulated dietary selenium concentrations were about 2.0-2.5 {mu} g {center_dot} g{sup -1} higher on the Gregg River than on reference streams for both species. When simulated dietary concentrations were considered, hatch failure rates on the Gregg River were predicted to average 12% higher in American Dippers and 8% higher in Harlequin Ducks than at reference streams. Corresponding values were only 3% for both species when predicted egg concentrations were used. Elevated levels of selenium in insects in some of the reference streams were unexpected and raised a question as to whether aquatic birds have evolved a higher tolerance level for dietary selenium in these areas.« less

  17. Direct and terrestrial vegetation-mediated effects of environmental change on aquatic ecosystem processes

    Treesearch

    Becky A. Ball; John S. Kominoski; Heather E. Adams; Stuart E. Jones; Evan S. Kane; Terrance D. Loecke; Wendy M. Mahaney; Jason P. Martina; Chelse M. Prather; Todd M.P. Robinson; Christopher T. Solomon

    2010-01-01

    Global environmental changes have direct effects on aquatic ecosystems, as well as indirect effects through alterations of adjacent terrestrial ecosystem structure and functioning. For example, shifts in terrestrial vegetation communities resulting from global changes can affect the quantity and quality of water, organic matter, and nutrient inputs to aquatic...

  18. Steady-state sulfur critical loads and exceedances for protection of aquatic ecosystems in the U.S. Southern Appalachian Mountains.

    PubMed

    McDonnell, Todd C; Sullivan, Timothy J; Hessburg, Paul F; Reynolds, Keith M; Povak, Nicholas A; Cosby, Bernard J; Jackson, William; Salter, R Brion

    2014-12-15

    Atmospherically deposited sulfur (S) causes stream water acidification throughout the eastern U.S. Southern Appalachian Mountain (SAM) region. Acidification has been linked with reduced fitness and richness of aquatic species and changes to benthic communities. Maintaining acid-base chemistry that supports native biota depends largely on balancing acidic deposition with the natural resupply of base cations. Stream water acid neutralizing capacity (ANC) is maintained by base cations that mostly originate from weathering of surrounding lithologies. When ambient atmospheric S deposition exceeds the critical load (CL) an ecosystem can tolerate, stream water chemistry may become lethal to biota. This work links statistical predictions of ANC and base cation weathering for streams and watersheds of the SAM region with a steady-state model to estimate CLs and exceedances. Results showed that 20.1% of the total length of study region streams displayed ANC <100 μeq∙L(-1), a level at which effects to biota may be anticipated; most were 4th or lower order streams. Nearly one-third of the stream length within the study region exhibited CLs of S deposition <50 meq∙m(-2)∙yr(-1), which is less than the regional average S deposition of 60 meq∙m(-2)∙yr(-1). Owing to their geologic substrates, relatively high elevation, and cool and moist forested conditions, the percentage of stream length in exceedance was highest for mountain wilderness areas and in national parks, and lowest for privately owned valley bottom land. Exceedance results were summarized by 12-digit hydrologic unit code (subwatershed) for use in developing management goals and policy objectives, and for long-term monitoring. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Bioconcentration, bioaccumulation, and metabolism of pesticides in aquatic organisms.

    PubMed

    Katagi, Toshiyuki

    2010-01-01

    The ecotoxicological assessment of pesticide effects in the aquatic environment should normally be based on a deep knowledge of not only the concentration of pesticides and metabolites found but also on the influence of key abiotic and biotic processes that effect rates of dissipation. Although the bioconcentration and bioaccumulation potentials of pesticides in aquatic organisms are conveniently estimated from their hydrophobicity (represented by log K(ow), it is still indispensable to factor in the effects of key abiotic and biotic processes on such pesticides to gain a more precise understanding of how they may have in the natural environment. Relying only on pesticide hydrophobicity may produce an erroneous environmental impact assessment. Several factors affect rates of pesticide dissipation and accumulation in the aquatic environment. Such factors include the amount and type of sediment present in the water and type of diet available to water-dwelling organisms. The particular physiological behavior profiles of aquatic organisms in water, such as capacity for uptake, metabolism, and elimination, are also compelling factors, as is the chemistry of the water. When evaluating pesticide uptake and bioconcentration processes, it is important to know the amount and nature of bottom sediments present and the propensity that the stuffed aquatic organisms have to absorb and process xenobiotics. Extremely hydrophobic pesticides such as the organochlorines and pyrethroids are susceptible to adsorb strongly to dissolved organic matter associated with bottom sediment. Such absorption reduces the bioavailable fraction of pesticide dissolved in the water column and reduces the probable ecotoxicological impact on aquatic organisms living the water. In contrast, sediment dweller may suffer from higher levels of direct exposure to a pesticide, unless it is rapidly degraded in sediment. Metabolism is important to bioconcentration and bioaccumulation processes, as is

  20. Direct and indirect effects of metal contamination on soil biota in a Zn-Pb post-mining and smelting area (S Poland).

    PubMed

    Kapusta, Paweł; Szarek-Łukaszewska, Grażyna; Stefanowicz, Anna M

    2011-06-01

    Effects of metal contamination on soil biota activity were investigated at 43 sites in 5 different habitats (defined by substratum and vegetation type) in a post-mining area. Sites were characterised in terms of soil pH and texture, nutrient status, total and exchangeable metal concentrations, as well as plant species richness and cover, abundances of enchytraeids, nematodes and tardigrades, and microbial respiration and biomass. The concentrations of total trace metals were highest in soils developed on mining waste (metal-rich dolomite), but these habitats were more attractive than sandy sites for plants and soil biota because of their higher content of organic matter, clay and nutrients. Soil mesofauna and microbes were strongly dependent on natural habitat properties. Pollution (exchangeable Zn and Cd) negatively affected only enchytraeid density; due to a positive relationship between enchytraeids and microbes it indirectly reduced microbial activity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Development of resource shed delineation in aquatic ecosystems

    EPA Science Inventory

    Environmental issues in aquatic ecosystems of high management priority involve spatially explicit phenomena that occur over vast areas. A "landscape" perspective is thus necessary, including an understanding of how ecological phenomena at a local scale are affected by physical fo...

  2. Interactions between Bt crops and aquatic ecosystems: A review.

    PubMed

    Venter, Hermoine J; Bøhn, Thomas

    2016-12-01

    The term Bt crops collectively refers to crops that have been genetically modified to include a gene (or genes) sourced from Bacillus thuringiensis (Bt) bacteria. These genes confer the ability to produce proteins toxic to certain insect pests. The interaction between Bt crops and adjacent aquatic ecosystems has received limited attention in research and risk assessment, despite the fact that some Bt crops have been in commercial use for 20 yr. Reports of effects on aquatic organisms such as Daphnia magna, Elliptio complanata, and Chironomus dilutus suggest that some aquatic species may be negatively affected, whereas other reports suggest that the decreased use of insecticides precipitated by Bt crops may benefit aquatic communities. The present study reviews the literature regarding entry routes and exposure pathways by which aquatic organisms may be exposed to Bt crop material, as well as feeding trials and field surveys that have investigated the effects of Bt-expressing plant material on such organisms. The present review also discusses how Bt crop development has moved past single-gene events, toward multigene stacked varieties that often contain herbicide resistance genes in addition to multiple Bt genes, and how their use (in conjunction with co-technology such as glyphosate/Roundup) may impact and interact with aquatic ecosystems. Lastly, suggestions for further research in this field are provided. Environ Toxicol Chem 2016;35:2891-2902. © 2016 SETAC. © 2016 SETAC.

  3. Effect of decabromodiphenyl ether (BDE-209) on a soil-biota system: Role of earthworms and ryegrass.

    PubMed

    Feng, Mingbao; He, Qun; Shi, Jiaqi; Qin, Li; Zhang, Xuesheng; Sun, Ping; Wang, Zunyao

    2016-06-01

    In the present study, the toxic effect of decabromodiphenyl ether (BDE-209), an important brominated fire retardant, on soil was evaluated by amending with different concentrations (0 mg/kg, 1 mg/kg, 10 mg/kg, and 500 mg/kg dry wt) for 40 d. The activities of 3 soil enzymes (urease, catalase, and alkaline phosphatase) were measured as the principal assessment endpoints. Meanwhile, the effects of natural environmental factors, such as light conditions and soil biota, on BDE-209 intoxication were studied. For the latter, 30 earthworms (Metaphire guillelmi) with fully matured clitella or ryegrass (Lolium perenne) with fully matured leaves were exposed in soil amended with BDE-209. The activities of the soil enzymes were adversely affected by BDE-209, especially for the high-concentration treatments, with greater adverse effects in the dark than in the light. The presence of earthworms reduced toxicity to BDE-209, whereas ryegrass did not. The calculated integrated biomarker response index, which provides a general indicator of the health status of test species by combining different biomarker signals, further validated these findings. Moreover, the antioxidant status (oxidant-antioxidant balance) of these 2 biota was assessed. Results indicated that BDE-209 significantly affected the activities of antioxidant enzymes (superoxide dismutase and catalase) and enhanced the levels of malondialdehyde in both species. The present study may facilitate a better understanding of the toxicity of BDE-209 toward the soil environment. Environ Toxicol Chem 2016;35:1349-1357. © 2015 SETAC. © 2015 SETAC.

  4. Large-Scale Environmental Influences on Aquatic Animal Health

    EPA Science Inventory

    In the latter portion of the 20th century, North America experienced numerous large-scale mortality events affecting a broad diversity of aquatic animals. Short-term forensic investigations of these events have sometimes characterized a causative agent or condition, but have rare...

  5. TiO2 nanoparticles for the remediation of eutrophic shallow freshwater systems: Efficiency and impacts on aquatic biota under a microcosm experiment.

    PubMed

    Bessa da Silva, Márcia; Abrantes, Nelson; Nogueira, Verónica; Gonçalves, Fernando; Pereira, Ruth

    2016-09-01

    The application of nanomaterials (NMs) in the remediation of eutrophic waters, particularly in the control of internal loading of nutrients, has been started, but limited investigations evaluated the effectiveness of these new treatment approaches and of their potential impacts on species from shallow freshwater lakes. The present work investigated, under a microcosm experiment, the application of a TiO2 nanomaterial both for reducing nutrient (mainly phosphorus and nitrogen forms) desorption and release from sediments (preventive treatment-PT) and for eliminating algal blooms (remediation treatment-RT). Furthermore, we also intended to assess the potential impacts of nano-TiO2 application on key freshwater species. The results showed the effectiveness of nano-TiO2 in controlling the release of phosphates from surface sediment and the subsequent reduction of total phosphorus in the water column. A reduction in total nitrogen was also observed. Such changes in nutrient dynamics contributed to a progressive inhibition of development of algae after the application of the NM in PT microcosms. Concerning the ability of nano-TiO2 to interact with algal cells, this interaction has likely occurred, mainly in RT, enhancing the formation of aggregates and their rapid settlement, thus reducing the algal bloom. Both treatments caused deleterious effects on freshwater species. In PT, Daphnia magna and Lemna minor showed a significant inhibition of several endpoints. Conversely, no inhibitory effect on the growth of Chironomus riparius was recorded. In opposite, C. riparius was the most affected species in RT microcosms. Such difference was probably caused by the formation of larger TiO2-algae aggregates in RT, under a high algal density, that rapidly settled in the sediment, becoming less available for pelagic species. In summary, despite the effectiveness of both treatments in controlling internal nutrient loading and in the mitigating algal bloom episodes, their negative

  6. Effects of Fungicides on Aquatic Fungi and Bacteria

    NASA Astrophysics Data System (ADS)

    Conners, D. E.; Rosemond, A. D.; Black, M. C.

    2005-05-01

    Aquatic microorganisms play an important role in conditioning leaf litter that enters streams and serves as an important base of production for consumers. Contamination of streams by fungicides may adversely affect microorganisms and alter leaf litter processing rates. Unfortunately, microorganisms are rarely used in acute toxicity tests for fungicide evaluation and registration. We adapted the resazurin reduction assay, which is used in medical microbiology, to assess the acute toxicity of four fungicides (azoxystrobin, trifloxystrobin, kresoxim-methyl and chlorothalonil) to aquatic fungi (Articulospora tetracladia) and bacteria (Cytophaga spp.), and investigated the ability of the toxicants to inhibit leaf breakdown in microcosms. Fungi were more sensitive to fungicides than many standard test organisms (cladocerans, green algae, trout), while bacteria were often the least sensitive. All of the fungicides except kresoxim-methyl, when added to microcosms at concentrations that inhibited the fungi by 90 percent in acute tests, reduced leaf breakdown rates by an average of 14.7 percent. Thus, aquatic fungi and their associated functions in streams may be relatively sensitive to fungicides applied terrestrially that enter streams through non-point sources. These data highlight the importance of including aquatic fungi in safety assessments of pesticides for protection of microbial function.

  7. Bioaccumulation and human health risk assessment of DDT and other organochlorine pesticides in an apex aquatic predator from a premier conservation area.

    PubMed

    Gerber, Ruan; Smit, Nico J; Van Vuren, Johan H J; Nakayama, Shouta M M; Yohannes, Yared B; Ikenaka, Yoshinori; Ishizuka, Mayumi; Wepener, Victor

    2016-04-15

    With the second highest gross domestic product in Africa, South Africa is known to have a high pesticide usage, including the highly persistent and banned group of organochlorine pesticides (OCPs). South Africa is also one of few countries to still actively spray DDT as malaria vector control. The aim of the study was to determine the degree to which aquatic biota in selected rivers of the world renowned Kruger National Park (KNP) are exposed to by use of OCPs in the catchments outside the KNP and how this exposure relates to human health. Tigerfish (Hydrocynus vittatus) are economically important apex predators and was selected as bioindicator for this study. Fish were sampled from the KNP sections of the Luvuvhu, Letaba and Olifants rivers during the high and low flow periods from 2010 to 2011 within the KNP and 19 OCPs were determined in muscle tissue using GC-ECD techniques. Significant flow related and spatial OCP bioaccumulation was observed. Tigerfish from the Luvuvhu River displayed the highest OCP bioaccumulation. Concentrations of the majority of the OCPs including the DDTs were the highest levels ever recorded from South African freshwater systems and in many cases the concentrations were higher than most contaminated areas from around the world. The concentrations found in H. vittatus muscle also exceeded maximum residue levels in edible fat as set by the European Union. The health risk assessment also demonstrated that the levels of OCPs pose very high cancer risks to the local populations consuming tigerfish, as high as 2 in 10 increased risk factor. This is of concern not only when managing the water resources of the conservation area but also for surrounding communities consuming freshwater fish. Contaminants enter the park from outside the borders and pose potential risks to the mandated conservation of aquatic biota within the KNP. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Five palaeobiological laws needed to understand the evolution of the living biota.

    PubMed

    Marshall, Charles R

    2017-05-23

    The foundations of several disciplines can be expressed as simple quantitative laws, for example, Newton's laws or the laws of thermodynamics. Here I present five laws derived from fossil data that describe the relationships among species extinction and longevity, species richness, origination rates, extinction rates and diversification. These statements of our palaeobiological knowledge constitute a dimension largely hidden from view when studying the living biota, which are nonetheless crucial to the study of evolution and ecology even for groups with poor or non-existent fossil records. These laws encapsulate: the critical fact of extinction; that species are typically geologically short-lived, and thus that the number of extinct species typically dwarfs the number of living species; that extinction and origination rates typically have similar magnitudes; and, that significant extinction makes it difficult to infer much about a clade's early history or its current diversity dynamics from the living biota alone. Although important strides are being made to integrate these core palaeontological findings into our analysis of the living biota, this knowledge needs to be incorporated more widely if we are to understand their evolutionary dynamics.

  9. Changes to the ocular biota with time in extended- and daily-wear disposable contact lens use.

    PubMed

    Stapleton, F; Willcox, M D; Fleming, C M; Hickson, S; Sweeney, D F; Holden, B A

    1995-11-01

    Gram-negative bacteria may play a role in the etiology of certain soft contact lens (SCL)-related diseases. Contact lens (CL) wear may modify the normal ocular biota, providing a more favorable environment for potential pathogens. This study reports temporal changes in ocular biota in daily-wear (DW) and extended-wear (EW) disposable SCL use in experienced and neophyte wearers. Lid margin and bulbar conjunctival biota were sampled prior to CL fitting in 26 previous DW SCL users, 18 previous EW SCL users, and 26 neophytes. Wearers were fitted with an etafilcon A CL in one eye and a polymacon CL in the fellow eye. Lenses were worn on a daily basis by the 26 previous DW SCL wearers and on an EW basis by the remaining 44 subjects. The ocular biota was further sampled after 1, 3, 6, 9, and 12 months of wear. The ocular biota consisted of coagulase-negative staphylococci, Corynebacterium spp., Micrococcus spp., and Propionibacterium spp. Potential pathogens were rarely isolated at baseline. No significant trend of increasing ocular colonization was shown for extended CL wear. Lid and conjunctival colonization increased with DW SCL use (P < 0.001), although this increase occurred for nonpathogenic species only. Fewer potential pathogens were isolated from DW SCL than from EW SCL users (P < 0.05). The lid margin consistently showed greater colonization than the conjunctiva and may be a source of potential pathogens during CL wear. Hydrogel CL wear appears to modify the ocular biota. An increased number of commensal organisms were present in DW SCL use. EW SCL use altered the spectrum of organisms isolated. These alterations may suppress the normal ocular defense mechanisms and may be relevant in the pathogenesis of CL-related disease.

  10. Changes to the ocular biota with time in extended- and daily-wear disposable contact lens use.

    PubMed Central

    Stapleton, F; Willcox, M D; Fleming, C M; Hickson, S; Sweeney, D F; Holden, B A

    1995-01-01

    Gram-negative bacteria may play a role in the etiology of certain soft contact lens (SCL)-related diseases. Contact lens (CL) wear may modify the normal ocular biota, providing a more favorable environment for potential pathogens. This study reports temporal changes in ocular biota in daily-wear (DW) and extended-wear (EW) disposable SCL use in experienced and neophyte wearers. Lid margin and bulbar conjunctival biota were sampled prior to CL fitting in 26 previous DW SCL users, 18 previous EW SCL users, and 26 neophytes. Wearers were fitted with an etafilcon A CL in one eye and a polymacon CL in the fellow eye. Lenses were worn on a daily basis by the 26 previous DW SCL wearers and on an EW basis by the remaining 44 subjects. The ocular biota was further sampled after 1, 3, 6, 9, and 12 months of wear. The ocular biota consisted of coagulase-negative staphylococci, Corynebacterium spp., Micrococcus spp., and Propionibacterium spp. Potential pathogens were rarely isolated at baseline. No significant trend of increasing ocular colonization was shown for extended CL wear. Lid and conjunctival colonization increased with DW SCL use (P < 0.001), although this increase occurred for nonpathogenic species only. Fewer potential pathogens were isolated from DW SCL than from EW SCL users (P < 0.05). The lid margin consistently showed greater colonization than the conjunctiva and may be a source of potential pathogens during CL wear. Hydrogel CL wear appears to modify the ocular biota. An increased number of commensal organisms were present in DW SCL use. EW SCL use altered the spectrum of organisms isolated. These alterations may suppress the normal ocular defense mechanisms and may be relevant in the pathogenesis of CL-related disease. PMID:7591092

  11. Public lakes, private lakeshore: Modeling protection of native aquatic plants

    USGS Publications Warehouse

    Schroeder, Susan A.; Fulton, David C.

    2013-01-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221–279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey (n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners’ behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  12. Public Lakes, Private Lakeshore: Modeling Protection of Native Aquatic Plants

    NASA Astrophysics Data System (ADS)

    Schroeder, Susan A.; Fulton, David C.

    2013-07-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221-279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey ( n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners' behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  13. WATER QUALITY CHANGES IN HYPORHEIC FLOW AT THE AQUATIC-TERRESTRIAL INTERFACE OF A LARGER RIVER

    EPA Science Inventory

    Exchange between river water and groundwater in hyporheic flow at the aquatic-terrestrial interface can importantly affect water quality and aquatic habitat in the main channel of large rivers and at off-channel sites that include flowing and stagnant side channels. With tracer ...

  14. Biomechanics and energetics in aquatic and semiaquatic mammals: platypus to whale.

    PubMed

    Fish, F E

    2000-01-01

    A variety of mammalian lineages have secondarily invaded the water. To locomote and thermoregulate in the aqueous medium, mammals developed a range of morphological, physiological, and behavioral adaptations. A distinct difference in the suite of adaptations, which affects energetics, is apparent between semiaquatic and fully aquatic mammals. Semiaquatic mammals swim by paddling, which is inefficient compared to the use of oscillating hydrofoils of aquatic mammals. Semiaquatic mammals swim at the water surface and experience a greater resistive force augmented by wave drag than submerged aquatic mammals. A dense, nonwettable fur insulates semiaquatic mammals, whereas aquatic mammals use a layer of blubber. The fur, while providing insulation and positive buoyancy, incurs a high energy demand for maintenance and limits diving depth. Blubber contours the body to reduce drag, is an energy reserve, and suffers no loss in buoyancy with depth. Despite the high energetic costs of a semiaquatic existence, these animals represent modern analogs of evolutionary intermediates between ancestral terrestrial mammals and their fully aquatic descendants. It is these intermediate animals that indicate which potential selection factors and mechanical constraints may have directed the evolution of more derived aquatic forms.

  15. Fire and aquatic ecosystems of the western USA: Current knowledge and key questions

    USGS Publications Warehouse

    Bisson, P.A.; Rieman, B.; Luce, C.; Hessburg, Paul F.; Lee, D.; Kershner, J.; Reeves, G.H.; Gresswell, Robert E.

    2003-01-01

    Understanding of the effects of wildland fire and fire management on aquatic and riparian ecosystems is an evolving field, with many questions still to be resolved. Limitations of current knowledge, and the certainty that fire management will continue, underscore the need to summarize available information. Integrating fire and fuels management with aquatic ecosystem conservation begins with recognizing that terrestrial and aquatic ecosystems are linked and dynamic, and that fire can play a critical role in maintaining aquatic ecological diversity. To protect aquatic ecosystems we argue that it will be important to: (1) accommodate fire-related and other ecological processes that maintain aquatic habitats and biodiversity, and not simply control fires or fuels; (2) prioritize projects according to risks and opportunities for fire control and the protection of aquatic ecosystems; and (3) develop new consistency in the management and regulatory process. Ultimately, all natural resource management is uncertain; the role of science is to apply experimental design and hypothesis testing to management applications that affect fire and aquatic ecosystems. Policy-makers and the public will benefit from an expanded appreciation of fire ecology that enables them to implement watershed management projects as experiments with hypothesized outcomes, adequate controls, and replication.

  16. Can ozone be used to control the spread of freshwater Aquatic Invasive Species?

    USGS Publications Warehouse

    Buley, Riley P.; Hasler, Caleb T.; Tix, John A.; Suski, Cory D.; Hubert, Terrance D.

    2017-01-01

    The introduction of aquatic invasive species to non-native habitats can cause negative ecological effects and also billions of dollars in economic damage to governments and private industries. Once aquatic invasive species are introduced, eradication may be difficult without adversely affecting native species and habitats, urging resource managers to find preventative methods to protect non-invaded areas. The use of ozone (O3) as a non-physical barrier has shown promise as it is lethal to a wide range of aquatic taxa, requires a short contact time, and is relatively environmentally safe in aquatic systems when compared to other chemicals. However, before O3 can be considered as an approach to prevent the spread of aquatic invasive species, its effects on non-target organisms and already established aquatic invasive species must be fully evaluated. A review of the current literature was conducted to summarize data regarding the effects of O3 on aquatic taxa including fish, macroinvertebrates, zooplankton, phytoplankton, microbes, and pathogens. In addition, we assessed the practicality of ozone applications to control the movement of aquatic invasive species, and identified data gaps concerning the use of O3 as a non-physical barrier in field applications.

  17. Assessing the effects of climate change on aquatic invasive species.

    PubMed

    Rahel, Frank J; Olden, Julian D

    2008-06-01

    Different components of global environmental change are typically studied and managed independently, although there is a growing recognition that multiple drivers often interact in complex and nonadditive ways. We present a conceptual framework and empirical review of the interactive effects of climate change and invasive species in freshwater ecosystems. Climate change is expected to result in warmer water temperatures, shorter duration of ice cover, altered streamflow patterns, increased salinization, and increased demand for water storage and conveyance structures. These changes will alter the pathways by which non-native species enter aquatic systems by expanding fish-culture facilities and water gardens to new areas and by facilitating the spread of species during floods. Climate change will influence the likelihood of new species becoming established by eliminating cold temperatures or winter hypoxia that currently prevent survival and by increasing the construction of reservoirs that serve as hotspots for invasive species. Climate change will modify the ecological impacts of invasive species by enhancing their competitive and predatory effects on native species and by increasing the virulence of some diseases. As a result of climate change, new prevention and control strategies such as barrier construction or removal efforts may be needed to control invasive species that currently have only moderate effects or that are limited by seasonally unfavorable conditions. Although most researchers focus on how climate change will increase the number and severity of invasions, some invasive coldwater species may be unable to persist under the new climate conditions. Our findings highlight the complex interactions between climate change and invasive species that will influence how aquatic ecosystems and their biota will respond to novel environmental conditions.

  18. Evolutionary refugia and ecological refuges: key concepts for conserving Australian arid zone freshwater biodiversity under climate change

    PubMed Central

    Davis, Jenny; Pavlova, Alexandra; Thompson, Ross; Sunnucks, Paul

    2013-01-01

    Refugia have been suggested as priority sites for conservation under climate change because of their ability to facilitate survival of biota under adverse conditions. Here, we review the likely role of refugial habitats in conserving freshwater biota in arid Australian aquatic systems where the major long-term climatic influence has been aridification. We introduce a conceptual model that characterizes evolutionary refugia and ecological refuges based on our review of the attributes of aquatic habitats and freshwater taxa (fishes and aquatic invertebrates) in arid Australia. We also identify methods of recognizing likely future refugia and approaches to assessing the vulnerability of arid-adapted freshwater biota to a warming and drying climate. Evolutionary refugia in arid areas are characterized as permanent, groundwater-dependent habitats (subterranean aquifers and springs) supporting vicariant relicts and short-range endemics. Ecological refuges can vary across space and time, depending on the dispersal abilities of aquatic taxa and the geographical proximity and hydrological connectivity of aquatic habitats. The most important are the perennial waterbodies (both groundwater and surface water fed) that support obligate aquatic organisms. These species will persist where suitable habitats are available and dispersal pathways are maintained. For very mobile species (invertebrates with an aerial dispersal phase) evolutionary refugia may also act as ecological refuges. Evolutionary refugia are likely future refugia because their water source (groundwater) is decoupled from local precipitation. However, their biota is extremely vulnerable to changes in local conditions because population extinction risks cannot be abated by the dispersal of individuals from other sites. Conservation planning must incorporate a high level of protection for aquifers that support refugial sites. Ecological refuges are vulnerable to changes in regional climate because they have little

  19. Evolutionary refugia and ecological refuges: key concepts for conserving Australian arid zone freshwater biodiversity under climate change.

    PubMed

    Davis, Jenny; Pavlova, Alexandra; Thompson, Ross; Sunnucks, Paul

    2013-07-01

    Refugia have been suggested as priority sites for conservation under climate change because of their ability to facilitate survival of biota under adverse conditions. Here, we review the likely role of refugial habitats in conserving freshwater biota in arid Australian aquatic systems where the major long-term climatic influence has been aridification. We introduce a conceptual model that characterizes evolutionary refugia and ecological refugees based on our review of the attributes of aquatic habitats and freshwater taxa (fishes and aquatic invertebrates) in arid Australia. We also identify methods of recognizing likely future refugia and approaches to assessing the vulnerability of arid-adapted freshwater biota to a warming and drying climate. Evolutionary refugia in arid areas are characterized as permanent, groundwater-dependent habitats (subterranean aquifers and springs) supporting vicariant relicts and short-range endemics. Ecological refugees can vary across space and time, depending on the dispersal abilities of aquatic taxa and the geographical proximity and hydrological connectivity of aquatic habitats. The most important are the perennial waterbodies (both groundwater and surface water fed) that support obligate aquatic organisms. These species will persist where suitable habitats are available and dispersal pathways are maintained. For very mobile species (invertebrates with an aerial dispersal phase) evolutionary refugia may also act as ecological refugees. Evolutionary refugia are likely future refugia because their water source (groundwater) is decoupled from local precipitation. However, their biota is extremely vulnerable to changes in local conditions because population extinction risks cannot be abated by the dispersal of individuals from other sites. Conservation planning must incorporate a high level of protection for aquifers that support refugial sites. Ecological refuges are vulnerable to changes in regional climate because they have

  20. Habitat Complexity in Aquatic Microcosms Affects Processes Driven by Detritivores

    PubMed Central

    Flores, Lorea; Bailey, R. A.; Elosegi, Arturo; Larrañaga, Aitor; Reiss, Julia

    2016-01-01

    Habitat complexity can influence predation rates (e.g. by providing refuge) but other ecosystem processes and species interactions might also be modulated by the properties of habitat structure. Here, we focussed on how complexity of artificial habitat (plastic plants), in microcosms, influenced short-term processes driven by three aquatic detritivores. The effects of habitat complexity on leaf decomposition, production of fine organic matter and pH levels were explored by measuring complexity in three ways: 1. as the presence vs. absence of habitat structure; 2. as the amount of structure (3 or 4.5 g of plastic plants); and 3. as the spatial configuration of structures (measured as fractal dimension). The experiment also addressed potential interactions among the consumers by running all possible species combinations. In the experimental microcosms, habitat complexity influenced how species performed, especially when comparing structure present vs. structure absent. Treatments with structure showed higher fine particulate matter production and lower pH compared to treatments without structures and this was probably due to higher digestion and respiration when structures were present. When we explored the effects of the different complexity levels, we found that the amount of structure added explained more than the fractal dimension of the structures. We give a detailed overview of the experimental design, statistical models and R codes, because our statistical analysis can be applied to other study systems (and disciplines such as restoration ecology). We further make suggestions of how to optimise statistical power when artificially assembling, and analysing, ‘habitat complexity’ by not confounding complexity with the amount of structure added. In summary, this study highlights the importance of habitat complexity for energy flow and the maintenance of ecosystem processes in aquatic ecosystems. PMID:27802267

  1. Bioaccumulation of five pharmaceuticals at multiple trophic levels in an aquatic food web - Insights from a field experiment.

    PubMed

    Lagesson, A; Fahlman, J; Brodin, T; Fick, J; Jonsson, M; Byström, P; Klaminder, J

    2016-10-15

    Pharmaceuticals derived from manufacturing and human consumption contaminate surface waters worldwide. To what extent such pharmaceutical contamination accumulates and disperses over time in different compartments of aquatic food webs is not well known. In this study we assess to what extent five pharmaceuticals (diphenhydramine, oxazepam, trimethoprim, diclofenac, and hydroxyzine) are taken up by fish (European perch) and four aquatic invertebrate taxa (damselfly larvae, mayfly larvae, waterlouse, and ramshorn snail), by tracing their bioconcentrations over several months in a semi-natural large-scale (pond) system. The results suggest both significant differences among drugs in their capacity to bioaccumulate and differences among species in uptake. While no support for in situ uptake of diclofenac and trimethoprim was found, oxazepam, diphenhydramine, and hydroxyzine were detected in all analyzed species. Here, the highest bioaccumulation factor (tissue:water ratio) was found for hydroxyzine. In the food web, the highest concentrations were found in the benthic species ramshorn snail and waterlouse, indicating that bottom-living organism at lower trophic positions are the prime receivers of the pharmaceuticals. In general, concentrations in the biota decreased over time in response to decreasing water concentrations. However, two interesting exceptions to this trend were noted. First, mayfly larvae (primarily grazers) showed peak concentrations (a fourfold increase) of oxazepam, diphenhydramine, and hydroxyzine about 30days after initial addition of pharmaceuticals. Second, perch (top-predator) showed an increase in concentrations of oxazepam throughout the study period. Our results show that drugs can remain bioavailable for aquatic organism for long time periods (weeks to months) and even re-enter the food web at a later time. As such, for an understanding of accumulation and dispersion of pharmaceuticals in aquatic food webs, detailed ecological knowledge is

  2. Predicting organic floc transport dynamics in shallow aquatic ecosystems: Insights from the field, the laboratory, and numerical modeling

    USGS Publications Warehouse

    Harvey, Judson W.; Noe, Gregory B.; Larsen, Laurel G.; Crimaldi, John P.

    2009-01-01

    Transport of particulate organic material can impact watershed sediment and nutrient budgets and can alter the geomorphologic evolution of shallow aquatic environments. Prediction of organic aggregate (“floc”) transport in these environments requires knowledge of how hydraulics and biota affect the entrainment, settling, and aggregation of particles. This study evaluated the aggregation and field transport dynamics of organic floc from a low‐gradient floodplain wetland with flow‐parallel ridges and sloughs in the Florida Everglades. Floc dynamics were evaluated in a rotating annular flume and in situ in the field. Under present managed conditions in the Everglades, floc is not entrained by mean flows but is suspended via biological production in the water column and bioturbation. Aggregation was a significant process affecting Everglades floc at high flume flow velocities (7.0 cm s−1) and during recovery from high flow; disaggregation was not significant for the tested flows. During moderate flows when floc dynamics are hydrodynamically controlled, it is possible to model floc transport using a single “operative floc diameter” that accurately predicts fluxes downstream and to the bed. In contrast, during high flows and recovery from high flows, aggregation dynamics should be simulated. When entrained by flow in open‐water sloughs, Everglades floc will be transported downstream in multiple deposition and reentrainment events but will undergo net settling when transported onto ridges of emergent vegetation. We hypothesize that net transport of material from open to vegetated areas during high flows is critical for forming and maintaining distinctive topographic patterning in the Everglades and other low‐gradient floodplains.

  3. Aquatic Contaminant and Mercury Simulation Modules Developed for Hydrologic and Hydraulic Models

    DTIC Science & Technology

    2016-07-01

    through the food chain. Human health may also be affected by ingesting contaminated water or fish. As a result, the criteria for protecting human...ER D C/ EL T R- 16 -8 Environmental Quality Technology Research Program Aquatic Contaminant and Mercury Simulation Modules Developed...Quality Technology Research Program ERDC/EL TR-16-8 July 2016 Aquatic Contaminant and Mercury Simulation Modules Developed for Hydrologic and

  4. Biota dose assessment of small mammals sampled near uranium mines in northern Arizona

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jannik, T.; Minter, K.; Kuhne, W.

    In 2015, the U. S. Geological Survey (USGS) collected approximately 50 small mammal carcasses from Northern Arizona uranium mines and other background locations. Based on the highest gross alpha results, 11 small mammal samples were selected for radioisotopic analyses. None of the background samples had significant gross alpha results. The 11 small mammals were identified relative to the three ‘indicator’ mines located south of Fredonia, AZ on the Kanab Plateau (Kanab North Mine, Pinenut Mine, and Arizona 1 Mine) (Figure 1-1) and are operated by Energy Fuels Resources Inc. (EFRI). EFRI annually reports soil analysis for uranium and radium-226 usingmore » Arizona Department of Environmental Quality (ADEQ)-approved Standard Operating Procedures for Soil Sampling (EFRI 2016a, 2016b, 2017). In combination with the USGS small mammal radioiosotopic tissue analyses, a biota dose assessment was completed by Savannah River National Laboratory (SRNL) using the RESidual RADioactivity-BIOTA (RESRAD-BIOTA, V. 1.8) dose assessment tool provided by the Argonne National Laboratory (ANL 2017).« less

  5. FACTORS AFFECTING COLORED DISSOLVED ORGANIC MATTER IN AQUATIC ENVIRONMENTS OF THE SOUTHEASTERN UNITED STATES

    EPA Science Inventory

    The sunlight-absorbing (colored) component of dissolved organic matter (CDOM) in aquatic environments is widely distributed in freshwaters and coastal regions where it influences the fate and transport of toxic organic substances and biologically-important metals such as mercury,...

  6. How does predation affect the bioaccumulation of hydrophobic organic compounds in aquatic organisms?

    PubMed

    Xia, Xinghui; Li, Husheng; Yang, Zhifeng; Zhang, Xiaotian; Wang, Haotian

    2015-04-21

    It is well-known that the body burden of hydrophobic organic compounds (HOCs) increases with the trophic level of aquatic organisms. However, the mechanism of HOC biomagnification is not fully understood. To fill this gap, this study investigated the effect of predation on the bioaccumulation of polycyclic aromatic hydrocarbons (PAHs), one type of HOC, in low-to-high aquatic trophic levels under constant freely dissolved PAH concentrations (1, 5, or 10 μg L(-1)) maintained by passive dosing systems. The tested PAHs included phenanthrene, anthracene, fluoranthene, and pyrene. The test organisms included zebrafish, which prey on Daphnia magna, and cichlids, which prey on zebrafish. The results revealed that for both zebrafish and cichlids, predation elevated the uptake and elimination rates of PAHs. The increase of uptake rate constant ranged from 20.8% to 39.4% in zebrafish with the amount of predation of 5 daphnids per fish per day, and the PAH uptake rate constant increased with the amount of predation. However, predation did not change the final bioaccumulation equilibrium; the equilibrium concentrations of PAHs in fish only depended on the freely dissolved concentration in water. Furthermore, the lipid-normalized water-based bioaccumulation factor of each PAH was constant for fish at different trophic levels. These findings infer that the final bioaccumulation equilibrium of PAHs is related to a partition between water and lipids in aquatic organisms, and predation between trophic levels does not change bioaccumulation equilibrium but bioaccumulation kinetics at stable freely dissolved PAH concentrations. This study suggests that if HOCs have not reached bioaccumulation equilibrium, biomagnification occurs due to enhanced uptake rates caused by predation in addition to higher lipid contents in higher trophic organisms. Otherwise, it is only due to the higher lipid contents in higher trophic organisms.

  7. Pre-mining trace element and radiation exposure to biota from a breccia pipe uranium mine in the Grand Canyon (Arizona, USA) watershed

    USGS Publications Warehouse

    Hinck, Jo E.; Cleveland, Danielle; Brumbaugh, William G.; Linder, Greg; Lankton, Julia S.

    2017-01-01

    The risks to wildlife and humans from uranium (U) mining in the Grand Canyon watershed are largely unknown. In addition to U, other co-occurring ore constituents contribute to risks to biological receptors depending on their toxicological profiles. This study characterizes the pre-mining concentrations of total arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se), thallium (Tl), U, and zinc (Zn); radiation levels; and histopathology in biota (vegetation, invertebrates, amphibians, birds, and mammals) at the Canyon Mine. Gross alpha levels were below the reporting limit (4 pCi/g) in all samples, and gross beta levels were indicative of background in vegetation (<10–17 pCi/g) and rodents (<10–43.5 pCi/g). Concentrations of U, Tl, Pb, Ni, Cu, and As in vegetation downwind from the mine were likely the result of aeolian transport. Chemical concentrations in rodents and terrestrial invertebrates indicate that surface disturbance during mine construction has not resulted in statistically significant spatial differences in fauna concentrations adjacent to the mine. Chemical concentrations in egg contents and nestlings of non-aquatic birds were less than method quantification limits or did not exceed toxicity thresholds. Bioaccumulation of As, Pb, Se, Tl, and U was evident in Western spadefoot (Spea multiplicata) tadpoles from the mine containment pond; concentrations of As (28.9–31.4 μg/g) and Se (5.81–7.20 μg/g) exceeded toxicity values and were significantly greater than in tadpoles from a nearby water source. Continued evaluation of As and Se in biota inhabiting and forging in the mine containment pond is warranted as mining progresses.

  8. Pre-mining trace element and radiation exposure to biota from a breccia pipe uranium mine in the Grand Canyon (Arizona, USA) watershed.

    PubMed

    Hinck, Jo Ellen; Cleveland, Danielle; Brumbaugh, William G; Linder, Greg; Lankton, Julia

    2017-02-01

    The risks to wildlife and humans from uranium (U) mining in the Grand Canyon watershed are largely unknown. In addition to U, other co-occurring ore constituents contribute to risks to biological receptors depending on their toxicological profiles. This study characterizes the pre-mining concentrations of total arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se), thallium (Tl), U, and zinc (Zn); radiation levels; and histopathology in biota (vegetation, invertebrates, amphibians, birds, and mammals) at the Canyon Mine. Gross alpha levels were below the reporting limit (4 pCi/g) in all samples, and gross beta levels were indicative of background in vegetation (<10-17 pCi/g) and rodents (<10-43.5 pCi/g). Concentrations of U, Tl, Pb, Ni, Cu, and As in vegetation downwind from the mine were likely the result of aeolian transport. Chemical concentrations in rodents and terrestrial invertebrates indicate that surface disturbance during mine construction has not resulted in statistically significant spatial differences in fauna concentrations adjacent to the mine. Chemical concentrations in egg contents and nestlings of non-aquatic birds were less than method quantification limits or did not exceed toxicity thresholds. Bioaccumulation of As, Pb, Se, Tl, and U was evident in Western spadefoot (Spea multiplicata) tadpoles from the mine containment pond; concentrations of As (28.9-31.4 μg/g) and Se (5.81-7.20 μg/g) exceeded toxicity values and were significantly greater than in tadpoles from a nearby water source. Continued evaluation of As and Se in biota inhabiting and forging in the mine containment pond is warranted as mining progresses.

  9. AQUATIC ECOSYSTEMS,

    EPA Science Inventory

    Aquatic ecosystems are a vital part of the urban water cycle (and of urban areas more broadly), and, if healthy, provide a range of goods and services valued by humans (Meyer 1997). For example, aquatic ecosystems (e.g., rivers, lakes, wetlands) provide potable water, food resou...

  10. Stoneflies and Campers: Teaching Campers about Aquatic Environments.

    ERIC Educational Resources Information Center

    Edelstein, Karen

    1994-01-01

    Summer camps can implement a biomonitoring program that determines water quality through study of aquatic insects. Such a program requires a minimum of equipment and allows campers to explore the natural world and absorb information that will affect their views of science and the environment. (LP)

  11. Density dependence, spatial scale and patterning in sessile biota.

    PubMed

    Gascoigne, Joanna C; Beadman, Helen A; Saurel, Camille; Kaiser, Michel J

    2005-09-01

    Sessile biota can compete with or facilitate each other, and the interaction of facilitation and competition at different spatial scales is key to developing spatial patchiness and patterning. We examined density and scale dependence in a patterned, soft sediment mussel bed. We followed mussel growth and density at two spatial scales separated by four orders of magnitude. In summer, competition was important at both scales. In winter, there was net facilitation at the small scale with no evidence of density dependence at the large scale. The mechanism for facilitation is probably density dependent protection from wave dislodgement. Intraspecific interactions in soft sediment mussel beds thus vary both temporally and spatially. Our data support the idea that pattern formation in ecological systems arises from competition at large scales and facilitation at smaller scales, so far only shown in vegetation systems. The data, and a simple, heuristic model, also suggest that facilitative interactions in sessile biota are mediated by physical stress, and that interactions change in strength and sign along a spatial or temporal gradient of physical stress.

  12. Endocrine disruption in aquatic systems: up-scaling research to address ecological consequences.

    PubMed

    Windsor, Fredric M; Ormerod, Steve J; Tyler, Charles R

    2018-02-01

    Endocrine-disrupting chemicals (EDCs) can alter biological function in organisms at environmentally relevant concentrations and are a significant threat to aquatic biodiversity, but there is little understanding of exposure consequences for populations, communities and ecosystems. The pervasive nature of EDCs within aquatic environments and their multiple sub-lethal effects make assessments of their impact especially important but also highly challenging. Herein, we review the data on EDC effects in aquatic systems focusing on studies assessing populations and ecosystems, and including how biotic and abiotic processes may affect, and be affected by, responses to EDCs. Recent research indicates a significant influence of behavioural responses (e.g. enhancing feeding rates), transgenerational effects and trophic cascades in the ecological consequences of EDC exposure. In addition, interactions between EDCs and other chemical, physical and biological factors generate uncertainty in our understanding of the ecological effects of EDCs within aquatic ecosystems. We illustrate how effect thresholds for EDCs generated from individual-based experimental bioassays of the types commonly applied using chemical test guidelines [e.g. Organisation for Economic Co-operation and Development (OECD)] may not necessarily reflect the hazards associated with endocrine disruption. We argue that improved risk assessment for EDCs in aquatic ecosystems urgently requires more ecologically oriented research as well as field-based assessments at population-, community- and food-web levels. © 2017 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.

  13. Desiccation of sediments affects assimilate transport within aquatic plants and carbon transfer to microorganisms.

    PubMed

    von Rein, I; Kayler, Z E; Premke, K; Gessler, A

    2016-11-01

    With the projected increase in drought duration and intensity in future, small water bodies, and especially the terrestrial-aquatic interfaces, will be subjected to longer dry periods with desiccation of the sediment. Drought effects on the plant-sediment microorganism carbon continuum may disrupt the tight linkage between plants and microbes which governs sediment carbon and nutrient cycling, thus having a potential negative impact on carbon sequestration of small freshwater ecosystems. However, research on drought effects on the plant-sediment carbon transfer in aquatic ecosystems is scarce. We therefore exposed two emergent aquatic macrophytes, Phragmites australis and Typha latifolia, to a month-long summer drought in a mesocosm experiment. We followed the fate of carbon from leaves to sediment microbial communities with 13 CO 2 pulse labelling and microbial phospholipid-derived fatty acid (PLFA) analysis. We found that drought reduced the total amount of carbon allocated to stem tissues but did not delay the transport. We also observed an increase in accumulation of 13 C-labelled sugars in roots and found a reduced incorporation of 13 C into the PLFAs of sediment microorganisms. Drought induced a switch in plant carbon allocation priorities, where stems received less new assimilates leading to reduced starch reserves whilst roots were prioritised with new assimilates, suggesting their use for osmoregulation. There were indications that the reduced carbon transfer from roots to microorganisms was due to the reduction of microbial activity via direct drought effects rather than to a decrease in root exudation or exudate availability. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  14. Toxicological benchmarks for screening potential contaminants of concern for effects on aquatic biota: 1994 Revision

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Suter, G.W. II; Mabrey, J.B.

    1994-07-01

    This report presents potential screening benchmarks for protection of aquatic life from contaminants in water. Because there is no guidance for screening benchmarks, a set of alternative benchmarks is presented herein. The alternative benchmarks are based on different conceptual approaches to estimating concentrations causing significant effects. For the upper screening benchmark, there are the acute National Ambient Water Quality Criteria (NAWQC) and the Secondary Acute Values (SAV). The SAV concentrations are values estimated with 80% confidence not to exceed the unknown acute NAWQC for those chemicals with no NAWQC. The alternative chronic benchmarks are the chronic NAWQC, the Secondary Chronicmore » Value (SCV), the lowest chronic values for fish and daphnids from chronic toxicity tests, the estimated EC20 for a sensitive species, and the concentration estimated to cause a 20% reduction in the recruit abundance of largemouth bass. It is recommended that ambient chemical concentrations be compared to all of these benchmarks. If NAWQC are exceeded, the chemicals must be contaminants of concern because the NAWQC are applicable or relevant and appropriate requirements (ARARs). If NAWQC are not exceeded, but other benchmarks are, contaminants should be selected on the basis of the number of benchmarks exceeded and the conservatism of the particular benchmark values, as discussed in the text. To the extent that toxicity data are available, this report presents the alternative benchmarks for chemicals that have been detected on the Oak Ridge Reservation. It also presents the data used to calculate benchmarks and the sources of the data. It compares the benchmarks and discusses their relative conservatism and utility.« less

  15. A Screening-Level Approach for Comparing Risks Affecting Aquatic Ecosystem Services over Socio-Environmental Gradients

    NASA Astrophysics Data System (ADS)

    Harmon, T. C.; Conde, D.; Villamizar, S. R.; Reid, B.; Escobar, J.; Rusak, J.; Hoyos, N.; Scordo, F.; Perillo, G. M.; Piccolo, M. C.; Zilio, M.; Velez, M.

    2015-12-01

    Assessing risks to aquatic ecosystems services (ES) is challenging and time-consuming, and effective strategies for prioritizing more detailed assessment efforts are needed. We propose a screening-level risk analysis (SRA) approach that scales ES risk using socioeconomic and environmental indices to capture anthropic and climatic pressures, as well as the capacity for institutional responses to those pressures. The method considers ES within a watershed context, and uses expert input to prioritize key services and the associated pressures that threaten them. The SRA approach focuses on estimating ES risk affect factors, which are the sum of the intensity factors for all hazards or pressures affecting the ES. We estimate the pressure intensity factors in a novel manner, basing them on the nation's (i) human development (proxied by Inequality-adjusted Human Development Index, IHDI), (ii) environmental regulatory and monitoring state (Environmental Performance Index, EPI) and (iii) the current level of water stress in the watershed (baseline water stress, BWS). Anthropic intensity factors for future conditions are derived from the baseline values based on the nation's 10-year trend in IHDI and EPI; ES risks in nations with stronger records of change are rewarded more/penalized less in estimates for good/poor future management scenarios. Future climatic intensity factors are tied to water stress estimates based on two general circulation model (GCM) outcomes. We demonstrate the method for an international array of six sites representing a wide range of socio-environmental settings. The outcomes illustrate novel consequences of the scaling scheme. Risk affect factors may be greater in a highly developed region under intense climatic pressure, or in less well-developed regions due to human factors (e.g., poor environmental records). As a screening-level tool, the SRA approach offers considerable promise for ES risk comparisons among watersheds and regions so that

  16. Physiological Integration Affects Expansion of an Amphibious Clonal Plant from Terrestrial to Cu-Polluted Aquatic Environments.

    PubMed

    Xu, Liang; Zhou, Zhen-Feng

    2017-03-08

    The effects of physiological integration on clonal plants growing in aquatic and terrestrial habitats have been extensively studied, but little is known about the role in the extension of amphibious clonal plants in the heterogeneous aquatic-terrestrial ecotones, especially when the water environments are polluted by heavy metals. Ramets of the amphibious clonal herb Alternanthera philoxeroides were rooted in unpolluted soil and polluted water at three concentrations of Cu. The extension of populations from unpolluted terrestrial to polluted aqueous environments mainly relied on stem elongation rather than production of new ramets. The absorbed Cu in the ramets growing in polluted water could be spread horizontally to other ramets in unpolluted soil via physiological integration and redistributed in different organs. The performances of ramets in both terrestrial and aquatic habitats were negatively correlated with Cu intensities in different organs of plants. It is concluded that physiological integration might lessen the fitness of connected ramets in heterogeneously polluted environments. The mechanical strength of the stems decreased with increasing Cu levels, especially in polluted water. We suggest that, except for direct toxicity to growth and expansion, heavy metal pollution might also increase the mechanical risk in breaking failure of plants.

  17. Physiological Integration Affects Expansion of an Amphibious Clonal Plant from Terrestrial to Cu-Polluted Aquatic Environments

    PubMed Central

    Xu, Liang; Zhou, Zhen-Feng

    2017-01-01

    The effects of physiological integration on clonal plants growing in aquatic and terrestrial habitats have been extensively studied, but little is known about the role in the extension of amphibious clonal plants in the heterogeneous aquatic-terrestrial ecotones, especially when the water environments are polluted by heavy metals. Ramets of the amphibious clonal herb Alternanthera philoxeroides were rooted in unpolluted soil and polluted water at three concentrations of Cu. The extension of populations from unpolluted terrestrial to polluted aqueous environments mainly relied on stem elongation rather than production of new ramets. The absorbed Cu in the ramets growing in polluted water could be spread horizontally to other ramets in unpolluted soil via physiological integration and redistributed in different organs. The performances of ramets in both terrestrial and aquatic habitats were negatively correlated with Cu intensities in different organs of plants. It is concluded that physiological integration might lessen the fitness of connected ramets in heterogeneously polluted environments. The mechanical strength of the stems decreased with increasing Cu levels, especially in polluted water. We suggest that, except for direct toxicity to growth and expansion, heavy metal pollution might also increase the mechanical risk in breaking failure of plants. PMID:28272515

  18. Physiological Integration Affects Expansion of an Amphibious Clonal Plant from Terrestrial to Cu-Polluted Aquatic Environments

    NASA Astrophysics Data System (ADS)

    Xu, Liang; Zhou, Zhen-Feng

    2017-03-01

    The effects of physiological integration on clonal plants growing in aquatic and terrestrial habitats have been extensively studied, but little is known about the role in the extension of amphibious clonal plants in the heterogeneous aquatic-terrestrial ecotones, especially when the water environments are polluted by heavy metals. Ramets of the amphibious clonal herb Alternanthera philoxeroides were rooted in unpolluted soil and polluted water at three concentrations of Cu. The extension of populations from unpolluted terrestrial to polluted aqueous environments mainly relied on stem elongation rather than production of new ramets. The absorbed Cu in the ramets growing in polluted water could be spread horizontally to other ramets in unpolluted soil via physiological integration and redistributed in different organs. The performances of ramets in both terrestrial and aquatic habitats were negatively correlated with Cu intensities in different organs of plants. It is concluded that physiological integration might lessen the fitness of connected ramets in heterogeneously polluted environments. The mechanical strength of the stems decreased with increasing Cu levels, especially in polluted water. We suggest that, except for direct toxicity to growth and expansion, heavy metal pollution might also increase the mechanical risk in breaking failure of plants.

  19. Summary of biological investigations relating to water quality in the Western Lake Michigan Drainages, Wisconsin and Michigan

    USGS Publications Warehouse

    Scudder, B.C.; Rheaume, S.J.; Parsons, S.R.; Lenz, B.N.

    1996-01-01

    Most biological studies related to waterquality conditions in the Western Lake Michigan Drainages have focused on populations and community structure of aquatic biota. Chemical concentrations in tissues of aquatic biota have been the next most common area of research. Our review suggests a paucity of data related to the health of all types of aquatic biota, especially amphibians, invertebrates, and reptiles; toxicity studies also were relatively uncommon. Overall, organisms primarily studied have been fish and invertebrates, although birds are most frequently examined in studies of organism health. The Fox/ Wolf Subbasin has been the focus of many more studies than the other subbasins, most likely because of the greater extent and severity of known water-quality problems in the Lower Fox River/Green Bay area over the past several decades and because it is the largest subbasin. Studies in the other subbasins are needed to adequately assess the water quality of these areas.

  20. Forest Management Intensity Affects Aquatic Communities in Artificial Tree Holes.

    PubMed

    Petermann, Jana S; Rohland, Anja; Sichardt, Nora; Lade, Peggy; Guidetti, Brenda; Weisser, Wolfgang W; Gossner, Martin M

    2016-01-01

    Forest management could potentially affect organisms in all forest habitats. However, aquatic communities in water-filled tree-holes may be especially sensitive because of small population sizes, the risk of drought and potential dispersal limitation. We set up artificial tree holes in forest stands subject to different management intensities in two regions in Germany and assessed the influence of local environmental properties (tree-hole opening type, tree diameter, water volume and water temperature) as well as regional drivers (forest management intensity, tree-hole density) on tree-hole insect communities (not considering other organisms such as nematodes or rotifers), detritus content, oxygen and nutrient concentrations. In addition, we compared data from artificial tree holes with data from natural tree holes in the same area to evaluate the methodological approach of using tree-hole analogues. We found that forest management had strong effects on communities in artificial tree holes in both regions and across the season. Abundance and species richness declined, community composition shifted and detritus content declined with increasing forest management intensity. Environmental variables, such as tree-hole density and tree diameter partly explained these changes. However, dispersal limitation, indicated by effects of tree-hole density, generally showed rather weak impacts on communities. Artificial tree holes had higher water temperatures (on average 2°C higher) and oxygen concentrations (on average 25% higher) than natural tree holes. The abundance of organisms was higher but species richness was lower in artificial tree holes. Community composition differed between artificial and natural tree holes. Negative management effects were detectable in both tree-hole systems, despite their abiotic and biotic differences. Our results indicate that forest management has substantial and pervasive effects on tree-hole communities and may alter their structure and

  1. Forest Management Intensity Affects Aquatic Communities in Artificial Tree Holes

    PubMed Central

    Petermann, Jana S.; Rohland, Anja; Sichardt, Nora; Lade, Peggy; Guidetti, Brenda; Weisser, Wolfgang W.; Gossner, Martin M.

    2016-01-01

    Forest management could potentially affect organisms in all forest habitats. However, aquatic communities in water-filled tree-holes may be especially sensitive because of small population sizes, the risk of drought and potential dispersal limitation. We set up artificial tree holes in forest stands subject to different management intensities in two regions in Germany and assessed the influence of local environmental properties (tree-hole opening type, tree diameter, water volume and water temperature) as well as regional drivers (forest management intensity, tree-hole density) on tree-hole insect communities (not considering other organisms such as nematodes or rotifers), detritus content, oxygen and nutrient concentrations. In addition, we compared data from artificial tree holes with data from natural tree holes in the same area to evaluate the methodological approach of using tree-hole analogues. We found that forest management had strong effects on communities in artificial tree holes in both regions and across the season. Abundance and species richness declined, community composition shifted and detritus content declined with increasing forest management intensity. Environmental variables, such as tree-hole density and tree diameter partly explained these changes. However, dispersal limitation, indicated by effects of tree-hole density, generally showed rather weak impacts on communities. Artificial tree holes had higher water temperatures (on average 2°C higher) and oxygen concentrations (on average 25% higher) than natural tree holes. The abundance of organisms was higher but species richness was lower in artificial tree holes. Community composition differed between artificial and natural tree holes. Negative management effects were detectable in both tree-hole systems, despite their abiotic and biotic differences. Our results indicate that forest management has substantial and pervasive effects on tree-hole communities and may alter their structure and

  2. Aquatic Therapy for Children

    ERIC Educational Resources Information Center

    Kucher, Greta; Moore, Kelsey; Rodia, Rachel; Moser, Christy Szczech

    2015-01-01

    Aquatic therapy has long been highlighted in the literature as a potentially powerful therapeutic intervention. This review will highlight basic definitions of aquatic therapy, review salient research, and identify specific diagnoses that may benefit from aquatic therapy. Online resources, blogs, and books that occupational therapists may find…

  3. Exposure Assessment Tools by Media - Aquatic Biota

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  4. Trace elements in soil and biota in confined disposal facilities for dredged material

    USGS Publications Warehouse

    Beyer, W.N.; Miller, G.; Simmers, J.W.

    1990-01-01

    We studied the relation of trace element concentrations in soil to those in house mice (Mus musculus), common reed (Phragmites australis) and ladybugs (Coccinella septempunctata) at five disposal facilities for dredged material. The sites had a wide range of soil trace element concentrations, acid soils and a depauperate fauna. They were very poor wildlife habitat because they were dominated by the common reed. Bioassay earthworms exposed to surface soils from three of the five sites died, whereas those exposed to four of five soils collected a meter deep survived, presumably because the deeper, unoxidized soil, was not as acid. Concentrations of Ni and Cr in the biota from each of the sites did not seem to be related to the concentrations of the same elements in soil. Although Pb, Zn and Cu concentrations in biota were correlated with those in soil, the range of concentrations in the biota was quite small compared to that in soil. The concentrations of Pb detected in mice were about as high as the concentrations previously reported in control mice from other studies. Mice from the most contaminated site (530 ppm Pb in soil) contained only slightly more Pb (8 ppm dry wt) than did mice (2-6 ppm dry wt) from sites containing much less Pb (22-92 ppm in soil). Despite the acid soil conditions, very little Cd was incorporated into food chains. Rather, Cd was leaching from the surface soil. We concluded that even the relatively high concentrations of trace elements in the acid dredged material studied did not cause high, concentrations of trace elements in the biota.

  5. IV. Aquatics

    Treesearch

    Michael K. Young

    2011-01-01

    The problem of invasive aquatic species has long been recognized by scientists at the Rocky Mountain Research Station. Fausch and others (2006, 2009) recently overviewed this issue. A point that often distinguishes nonnative aquatic species from nonnatives in other environments is that the presence of some species is frequently prized by managers and the public. For...

  6. 11. Chernobyl's radioactive impact on microbial biota.

    PubMed

    Yablokov, Alexey V

    2009-11-01

    Of the few microorganisms that have been studied, all underwent rapid changes in the areas heavily contaminated by Chernobyl. Organisms such as tuberculosis bacilli; hepatitis, herpes, and tobacco mosaic viruses; cytomegalovirus; and soil micromycetes and bacteria were activated in various ways. The ultimate long-term consequences for the Chernobyl microbiologic biota may be worse than what we know today. Compared to humans and other mammals, the profound changes that take place among these small live organisms with rapid reproductive turnover do not bode well for the health and survival of other species.

  7. Freshwater biodiversity and aquatic insect diversification.

    PubMed

    Dijkstra, Klaas-Douwe B; Monaghan, Michael T; Pauls, Steffen U

    2014-01-01

    Inland waters cover less than 1% of Earth's surface but harbor more than 6% of all insect species: Nearly 100,000 species from 12 orders spend one or more life stages in freshwater. Little is known about how this remarkable diversity arose, although allopatric speciation and ecological adaptation are thought to be primary mechanisms. Freshwater habitats are highly susceptible to environmental change and exhibit marked ecological gradients. Standing waters appear to harbor more dispersive species than running waters, but there is little understanding of how this fundamental ecological difference has affected diversification. In contrast to the lack of evolutionary studies, the ecology and habitat preferences of aquatic insects have been intensively studied, in part because of their widespread use as bioindicators. The combination of phylogenetics with the extensive ecological data provides a promising avenue for future research, making aquatic insects highly suitable models for the study of ecological diversification.

  8. Deposition of chromium in aquatic ecosystem from effluents of handloom textile industries in Ranaghat-Fulia region of West Bengal, India.

    PubMed

    Sanyal, Tanmay; Kaviraj, Anilava; Saha, Subrata

    2015-11-01

    Accumulation of chromium (Cr) was determined in water, sediment, aquatic plants, invertebrates and fish in aquatic ecosystems receiving effluents from handloom textile industries in Ranaghat-Fulia region of West Bengal in India. Cr was determined in the samples by atomic absorption spectrophotometer and data were analyzed functionally by Genetic Algorithm to determine trend of depositions of Cr in the sediment and water. Area plot curve was used to represent accumulation of Cr in biota. The results indicate that the aquatic ecosystems receiving the effluents from handloom textile factories are heavily contaminated by Cr. The contamination is hardly reflected in the concentration of Cr in water, but sediment exhibits seasonal fluctuation in deposition of Cr, concentration reaching to as high as 451.0 μg g(-1) during the peak production period. There is a clear trend of gradual increase in the deposition of Cr in the sediment. Aquatic weed, insect and mollusk specimens collected from both closed water bodies (S1 & S2) and riverine resources (S3 & S4) showed high rate of accumulation of Cr. Maximum concentration of Cr was detected in roots of aquatic weeds (877.5 μg g(-1)). Fish specimens collected from the polluted sites (S3 & S4) of river Churni showed moderate to high concentration of Cr in different tissues. Maximum concentration was detected in the liver of Glossogobius giuris (679.7 μg g(-1)) during monsoon followed by gill of Mystus bleekeri (190.0 μg g(-1)) and gut of G. giuris (123.7 μg g(-1)) during summer. Eutropiichthys vacha showed moderately high concentration of Cr in different tissues (65-99 μg g(-1)) while Puntius sarana showed relatively low concentration of Cr (below detection limit to 18.0 μg g(-1)) in different tissues except in gill (64.4 μg g(-1)).

  9. Deposition of chromium in aquatic ecosystem from effluents of handloom textile industries in Ranaghat–Fulia region of West Bengal, India

    PubMed Central

    Sanyal, Tanmay; Kaviraj, Anilava; Saha, Subrata

    2014-01-01

    Accumulation of chromium (Cr) was determined in water, sediment, aquatic plants, invertebrates and fish in aquatic ecosystems receiving effluents from handloom textile industries in Ranaghat–Fulia region of West Bengal in India. Cr was determined in the samples by atomic absorption spectrophotometer and data were analyzed functionally by Genetic Algorithm to determine trend of depositions of Cr in the sediment and water. Area plot curve was used to represent accumulation of Cr in biota. The results indicate that the aquatic ecosystems receiving the effluents from handloom textile factories are heavily contaminated by Cr. The contamination is hardly reflected in the concentration of Cr in water, but sediment exhibits seasonal fluctuation in deposition of Cr, concentration reaching to as high as 451.0 μg g−1 during the peak production period. There is a clear trend of gradual increase in the deposition of Cr in the sediment. Aquatic weed, insect and mollusk specimens collected from both closed water bodies (S1 & S2) and riverine resources (S3 & S4) showed high rate of accumulation of Cr. Maximum concentration of Cr was detected in roots of aquatic weeds (877.5 μg g−1). Fish specimens collected from the polluted sites (S3 & S4) of river Churni showed moderate to high concentration of Cr in different tissues. Maximum concentration was detected in the liver of Glossogobius giuris (679.7 μg g−1) during monsoon followed by gill of Mystus bleekeri (190.0 μg g−1) and gut of G. giuris (123.7 μg g−1) during summer. Eutropiichthys vacha showed moderately high concentration of Cr in different tissues (65–99 μg g−1) while Puntius sarana showed relatively low concentration of Cr (below detection limit to 18.0 μg g−1) in different tissues except in gill (64.4 μg g−1). PMID:26644938

  10. Radiocarbon Depression in Aquatic Foodwebs of the Colorado River, USA: Coupling Between Carbonate Weathering and the Biosphere

    NASA Astrophysics Data System (ADS)

    Sickman, J. O.; Huang, W.; Lucero, D.; Anderson, M.

    2012-12-01

    The 14C isotopic composition of living organisms is generally considered to be in isotopic equilibrium with atmosphere CO2. During the course of investigations of aquatic foodwebs of the Colorado River, we measured substantial radiocarbon depression of organisms within planktonic and benthic foodwebs of Copper Basin Reservoir, a short residence-time water body at the intake to the Colorado River Aqueduct. All trophic levels had depressed radiocarbon content with inferred "age" of ca. 1,200 radiocarbon years (range: 0.85 to 0.87 fraction modern carbon (fmc)). Additional measurements of the radiocarbon content of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) were made in other major rivers in California (New (near Salton Sea), Santa Ana (near Riverside), San Joaquin (near Fresno) and Salinas (near San Luis Obispo)). In the New River (which is composed primarily of irrigation tailwater derived from the Colorado River), the radiocarbon values for DIC closely matched those found in biota of the Copper Basin Reservoir (0.85 to 0.87 fmc), but radiocarbon values for DOC were slightly higher (0.91 to 0.95 fmc). In the other California rivers, radiocarbon concentrations in DIC were generally below modern and lower than corresponding levels in DOC; in the case of the Santa Ana River, DOC was older than DIC as a result of wastewater inputs from upstream treatment plants. Together these data suggest that the carbonate equilibrium of California rivers is influenced by weathering of carbonate minerals which produces HCO3- with no 14C. We hypothesize that this dead carbon can move into aquatic foodwebs via algae and phytoplankton uptake during photosynthesis, depressing the 14C content of aquatic foodwebs below that of the atmosphere. Based on a simple two-component mixing model incorporating carbonate weathering and atmospheric CO2, we estimate that 15-17% of the carbon in the aquatic foodweb of Copper Basin is derived directly from mineral weathering of

  11. Enantiomer specific measurements of current-use pesticides in aquatic systems

    EPA Science Inventory

    Contrary to predictions, current-use pesticides are adversely affecting aquatic systems in both urban and agricultural watersheds, particularly in California. One possible divergence from fate and effect predictions is that some current-use pesticides are chiral molecules. Increa...

  12. GLOBAL CLIMATE AND LARGE-SCALE INFLUENCES ON AQUATIC ANIMAL HEALTH

    EPA Science Inventory

    The last 3 decades have witnessed numerous large-scale mortality events of aquatic organisms in North America. Affected species range from ecologically-important sea urchins to commercially-valuable American lobsters and protected marine mammals. Short-term forensic investigation...

  13. Effects of ship-induced waves on aquatic ecosystems.

    PubMed

    Gabel, Friederike; Lorenz, Stefan; Stoll, Stefan

    2017-12-01

    Most larger water bodies worldwide are used for navigation, and the intensity of commercial and recreational navigation is expected to further increase. Navigation profoundly affects aquatic ecosystems. To facilitate navigation, rivers are trained and developed, and the direct effects of navigation include chemical and biological impacts (e.g., inputs of toxic substances and dispersal of non-native species, respectively). Furthermore, propagating ships create hydrodynamic alterations, often simply summarized as waves. Although ship-induced waves are recognized as influential stressors, knowledge on their effects is poorly synthesized. We present here a review on the effects of ship-induced waves on the structure, function and services of aquatic ecosystems based on more than 200 peer reviewed publications and technical reports. Ship-induced waves act at multiple organizational levels and different spatial and temporal scales. All the abiotic and biotic components of aquatic ecosystems are affected, from the sediment and nutrient budget to the planktonic, benthic and fish communities. We highlight how the effects of ship-induced waves cascade through ecosystems and how different effects interact and feed back into the ecosystem finally leading to altered ecosystem services and human health effects. Based on this synthesis of wave effects, we discuss strategies for mitigation. This may help to develop scientifically based and target-oriented management plans for navigational waters that optimize abiotic and biotic integrity and their ecosystem services and uses. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. EPA Region 7 Aquatic Focus Areas (ECO_RES.R7_AQUATIC_FOCUS_AREAS)

    EPA Pesticide Factsheets

    This shapefile consists of 347 individual Aquatic Ecological System (AES) polygons that are the Aquatic Conservation Focus Areas for EPA Region 7. The focus areas are those areas within each aquatic ecological system types that, if preserved, would maintain the biological and ecological diversity extant within that ecological system type. The layer consists of those polygons from the R7_AES.shp shapefile that had the highest ranks. The AES polygons in the Missouri portion of the file were appended and are those that contain the 158 aquatic conservation opportunity areas identified in Missouri as part of another project (Missouri Department of Conservation Aquatic Biodiversity Assessment 2005). Note that the identifiers in the Missouri portion of this file will not match the ID's in any Missouri specific files.

  15. Enantiomer Specific Measurements of Current-Use Pesticides in Aquatic Systems.

    EPA Science Inventory

    Research has shown that current-use pesticides can enter urban and agricultural watersheds and adversely affect aquatic organisms. A potential cause may be higher concentrations of the more toxic pesticide enantiomer present in the pesticide mixture. The presence of pesticide ena...

  16. Factors Affecting Stakeholders' Willingness to Pay to Prevent the Spread of Aquatic Nuisance Species

    ERIC Educational Resources Information Center

    Blaine, Thomas W.; Lichtkoppler, Frank R.

    2016-01-01

    Physical separation of the Great Lakes and Mississippi River basins has been identified as the most effective method for preventing the transfer of aquatic nuisance species, particularly Asian carp, from the Mississippi River Basin to the Great Lakes. The U.S. Army Corps of Engineers selected Extension to conduct a study of a key stakeholder…

  17. Sound the alarm: A meta-analysis on the effect of aquatic noise on fish behavior and physiology.

    PubMed

    Cox, Kieran; Brennan, Lawrence P; Gerwing, Travis G; Dudas, Sarah E; Juanes, Francis

    2018-07-01

    The aquatic environment is increasingly bombarded by a wide variety of noise pollutants whose range and intensity are increasing with each passing decade. Yet, little is known about how aquatic noise affects marine communities. To determine the implications that changes to the soundscape may have on fishes, a meta-analysis was conducted focusing on the ramifications of noise on fish behavior and physiology. Our meta-analysis identified 42 studies that produced 2,354 data points, which in turn indicated that anthropogenic noise negatively affects fish behavior and physiology. The most predominate responses occurred within foraging ability, predation risk, and reproductive success. Additionally, anthropogenic noise was shown to increase the hearing thresholds and cortisol levels of numerous species while tones, biological, and environmental noise were most likely to affect complex movements and swimming abilities. These findings suggest that the majority of fish species are sensitive to changes in the aquatic soundscape, and depending on the noise source, species responses may have extreme and negative fitness consequences. As such, this global synthesis should serve as a warning of the potentially dire consequences facing marine ecosystems if alterations to aquatic soundscapes continue on their current trajectory. © 2018 John Wiley & Sons Ltd.

  18. Assessing the TMDL Approach to Water Quality Management

    NASA Astrophysics Data System (ADS)

    Aswathanarayana, U.

    Every human being on Earth is a stakeholder in water quality management. And so, for that matter, is every animal, domesticated or wild, though they have no constituency Water quality includes not only considerations of water composition for multiple human uses such as drinking and irrigation, but also in terms of its capacity to support systems of aquatic biota in general. This is so because we now realize that our well-being is inseparable from the well-being of, say the aquatic biota. If frogs were dying, we would be next in line!

  19. Interactions between marine biota and ENSO: a conceptual model analysis

    NASA Astrophysics Data System (ADS)

    Heinemann, M.; Timmermann, A.; Feudel, U.

    2011-01-01

    We develop a conceptual coupled atmosphere-ocean-ecosystem model for the tropical Pacific to investigate the interaction between marine biota and the El Niño-Southern Oscillation (ENSO). Ocean and atmosphere are represented by a two-box model for the equatorial Pacific cold tongue and the warm pool, including a simplified mixed layer scheme. Marine biota are represented by a three-component (nutrient, phytoplankton, and zooplankton) ecosystem model. The atmosphere-ocean model exhibits an oscillatory state which qualitatively captures the main physics of ENSO. During an ENSO cycle, the variation of nutrient upwelling, and, to a small extent, the variation of photosynthetically available radiation force an ecosystem oscillation. The simplified ecosystem in turn, due to the effect of phytoplankton on the absorption of shortwave radiation in the water column, leads to (1) a warming of the tropical Pacific, (2) a reduction of the ENSO amplitude, and (3) a prolongation of the ENSO period. We qualitatively investigate these bio-physical coupling mechanisms using continuation methods. It is demonstrated that bio-physical coupling may play a considerable role in modulating ENSO variability.

  20. Paleoclimatic modeling and phylogeography of least killifish, Heterandria formosa: insights into Pleistocene expansion-contraction dynamics and evolutionary history of North American Coastal Plain freshwater biota.

    PubMed

    Bagley, Justin C; Sandel, Michael; Travis, Joseph; Lozano-Vilano, María de Lourdes; Johnson, Jerald B

    2013-10-09

    Climatic and sea-level fluctuations throughout the last Pleistocene glacial cycle (~130-0 ka) profoundly influenced present-day distributions and genetic diversity of Northern Hemisphere biotas by forcing range contractions in many species during the glacial advance and allowing expansion following glacial retreat ('expansion-contraction' model). Evidence for such range dynamics and refugia in the unglaciated Gulf-Atlantic Coastal Plain stems largely from terrestrial species, and aquatic species Pleistocene responses remain relatively uninvestigated. Heterandria formosa, a wide-ranging regional endemic, presents an ideal system to test the expansion-contraction model within this biota. By integrating ecological niche modeling and phylogeography, we infer the Pleistocene history of this livebearing fish (Poeciliidae) and test for several predicted distributional and genetic effects of the last glaciation. Paleoclimatic models predicted range contraction to a single southwest Florida peninsula refugium during the Last Glacial Maximum, followed by northward expansion. We inferred spatial-population subdivision into four groups that reflect genetic barriers outside this refuge. Several other features of the genetic data were consistent with predictions derived from an expansion-contraction model: limited intraspecific divergence (e.g. mean mtDNA p-distance = 0.66%); a pattern of mtDNA diversity (mean Hd = 0.934; mean π = 0.007) consistent with rapid, recent population expansion; a lack of mtDNA isolation-by-distance; and clinal variation in allozyme diversity with higher diversity at lower latitudes near the predicted refugium. Statistical tests of mismatch distributions and coalescent simulations of the gene tree lent greater support to a scenario of post-glacial expansion and diversification from a single refugium than to any other model examined (e.g. multiple-refugia scenarios). Congruent results from diverse data indicate H. formosa fits the classic Pleistocene

  1. Long-term and realistic global change manipulations had low impact on diversity of soil biota in temperate heathland

    NASA Astrophysics Data System (ADS)

    Holmstrup, Martin; Damgaard, Christian; Schmidt, Inger K.; Arndal, Marie F.; Beier, Claus; Mikkelsen, Teis N.; Ambus, Per; Larsen, Klaus S.; Pilegaard, Kim; Michelsen, Anders; Andresen, Louise C.; Haugwitz, Merian; Bergmark, Lasse; Priemé, Anders; Zaitsev, Andrey S.; Georgieva, Slavka; Dam, Marie; Vestergård, Mette; Christensen, Søren

    2017-01-01

    In a dry heathland ecosystem we manipulated temperature (warming), precipitation (drought) and atmospheric concentration of CO2 in a full-factorial experiment in order to investigate changes in below-ground biodiversity as a result of future climate change. We investigated the responses in community diversity of nematodes, enchytraeids, collembolans and oribatid mites at two and eight years of manipulations. We used a structural equation modelling (SEM) approach analyzing the three manipulations, soil moisture and temperature, and seven soil biological and chemical variables. The analysis revealed a persistent and positive effect of elevated CO2 on litter C:N ratio. After two years of treatment, the fungi to bacteria ratio was increased by warming, and the diversities within oribatid mites, collembolans and nematode groups were all affected by elevated CO2 mediated through increased litter C:N ratio. After eight years of treatment, however, the CO2-increased litter C:N ratio did not influence the diversity in any of the four fauna groups. The number of significant correlations between treatments, food source quality, and soil biota diversities was reduced from six to three after two and eight years, respectively. These results suggest a remarkable resilience within the soil biota against global climate change treatments in the long term.

  2. Long-term and realistic global change manipulations had low impact on diversity of soil biota in temperate heathland

    PubMed Central

    Holmstrup, Martin; Damgaard, Christian; Schmidt, Inger K.; Arndal, Marie F.; Beier, Claus; Mikkelsen, Teis N.; Ambus, Per; Larsen, Klaus S.; Pilegaard, Kim; Michelsen, Anders; Andresen, Louise C.; Haugwitz, Merian; Bergmark, Lasse; Priemé, Anders; Zaitsev, Andrey S.; Georgieva, Slavka; Dam, Marie; Vestergård, Mette; Christensen, Søren

    2017-01-01

    In a dry heathland ecosystem we manipulated temperature (warming), precipitation (drought) and atmospheric concentration of CO2 in a full-factorial experiment in order to investigate changes in below-ground biodiversity as a result of future climate change. We investigated the responses in community diversity of nematodes, enchytraeids, collembolans and oribatid mites at two and eight years of manipulations. We used a structural equation modelling (SEM) approach analyzing the three manipulations, soil moisture and temperature, and seven soil biological and chemical variables. The analysis revealed a persistent and positive effect of elevated CO2 on litter C:N ratio. After two years of treatment, the fungi to bacteria ratio was increased by warming, and the diversities within oribatid mites, collembolans and nematode groups were all affected by elevated CO2 mediated through increased litter C:N ratio. After eight years of treatment, however, the CO2-increased litter C:N ratio did not influence the diversity in any of the four fauna groups. The number of significant correlations between treatments, food source quality, and soil biota diversities was reduced from six to three after two and eight years, respectively. These results suggest a remarkable resilience within the soil biota against global climate change treatments in the long term. PMID:28120893

  3. Long-term and realistic global change manipulations had low impact on diversity of soil biota in temperate heathland.

    PubMed

    Holmstrup, Martin; Damgaard, Christian; Schmidt, Inger K; Arndal, Marie F; Beier, Claus; Mikkelsen, Teis N; Ambus, Per; Larsen, Klaus S; Pilegaard, Kim; Michelsen, Anders; Andresen, Louise C; Haugwitz, Merian; Bergmark, Lasse; Priemé, Anders; Zaitsev, Andrey S; Georgieva, Slavka; Dam, Marie; Vestergård, Mette; Christensen, Søren

    2017-01-25

    In a dry heathland ecosystem we manipulated temperature (warming), precipitation (drought) and atmospheric concentration of CO 2 in a full-factorial experiment in order to investigate changes in below-ground biodiversity as a result of future climate change. We investigated the responses in community diversity of nematodes, enchytraeids, collembolans and oribatid mites at two and eight years of manipulations. We used a structural equation modelling (SEM) approach analyzing the three manipulations, soil moisture and temperature, and seven soil biological and chemical variables. The analysis revealed a persistent and positive effect of elevated CO 2 on litter C:N ratio. After two years of treatment, the fungi to bacteria ratio was increased by warming, and the diversities within oribatid mites, collembolans and nematode groups were all affected by elevated CO 2 mediated through increased litter C:N ratio. After eight years of treatment, however, the CO 2 -increased litter C:N ratio did not influence the diversity in any of the four fauna groups. The number of significant correlations between treatments, food source quality, and soil biota diversities was reduced from six to three after two and eight years, respectively. These results suggest a remarkable resilience within the soil biota against global climate change treatments in the long term.

  4. Tool use by aquatic animals

    PubMed Central

    Mann, Janet; Patterson, Eric M.

    2013-01-01

    Tool-use research has focused primarily on land-based animals, with less consideration given to aquatic animals and the environmental challenges and conditions they face. Here, we review aquatic tool use and examine the contributing ecological, physiological, cognitive and social factors. Tool use among aquatic animals is rare but taxonomically diverse, occurring in fish, cephalopods, mammals, crabs, urchins and possibly gastropods. While additional research is required, the scarcity of tool use can likely be attributable to the characteristics of aquatic habitats, which are generally not conducive to tool use. Nonetheless, studying tool use by aquatic animals provides insights into the conditions that promote and inhibit tool-use behaviour across biomes. Like land-based tool users, aquatic animals tend to find tools on the substrate and use tools during foraging. However, unlike on land, tool users in water often use other animals (and their products) and water itself as a tool. Among sea otters and dolphins, the two aquatic tool users studied in greatest detail, some individuals specialize in tool use, which is vertically socially transmitted possibly because of their long dependency periods. In all, the contrasts between aquatic- and land-based tool users enlighten our understanding of the adaptive value of tool-use behaviour. PMID:24101631

  5. Tool use by aquatic animals.

    PubMed

    Mann, Janet; Patterson, Eric M

    2013-11-19

    Tool-use research has focused primarily on land-based animals, with less consideration given to aquatic animals and the environmental challenges and conditions they face. Here, we review aquatic tool use and examine the contributing ecological, physiological, cognitive and social factors. Tool use among aquatic animals is rare but taxonomically diverse, occurring in fish, cephalopods, mammals, crabs, urchins and possibly gastropods. While additional research is required, the scarcity of tool use can likely be attributable to the characteristics of aquatic habitats, which are generally not conducive to tool use. Nonetheless, studying tool use by aquatic animals provides insights into the conditions that promote and inhibit tool-use behaviour across biomes. Like land-based tool users, aquatic animals tend to find tools on the substrate and use tools during foraging. However, unlike on land, tool users in water often use other animals (and their products) and water itself as a tool. Among sea otters and dolphins, the two aquatic tool users studied in greatest detail, some individuals specialize in tool use, which is vertically socially transmitted possibly because of their long dependency periods. In all, the contrasts between aquatic- and land-based tool users enlighten our understanding of the adaptive value of tool-use behaviour.

  6. Study of the uncertainty in estimation of the exposure of non-human biota to ionising radiation.

    PubMed

    Avila, R; Beresford, N A; Agüero, A; Broed, R; Brown, J; Iospje, M; Robles, B; Suañez, A

    2004-12-01

    Uncertainty in estimations of the exposure of non-human biota to ionising radiation may arise from a number of sources including values of the model parameters, empirical data, measurement errors and biases in the sampling. The significance of the overall uncertainty of an exposure assessment will depend on how the estimated dose compares with reference doses used for risk characterisation. In this paper, we present the results of a study of the uncertainty in estimation of the exposure of non-human biota using some of the models and parameters recommended in the FASSET methodology. The study was carried out for semi-natural terrestrial, agricultural and marine ecosystems, and for four radionuclides (137Cs, 239Pu, 129I and 237Np). The parameters of the radionuclide transfer models showed the highest sensitivity and contributed the most to the uncertainty in the predictions of doses to biota. The most important ones were related to the bioavailability and mobility of radionuclides in the environment, for example soil-to-plant transfer factors, the bioaccumulation factors for marine biota and the gut uptake fraction for terrestrial mammals. In contrast, the dose conversion coefficients showed low sensitivity and contributed little to the overall uncertainty. Radiobiological effectiveness contributed to the overall uncertainty of the dose estimations for alpha emitters although to a lesser degree than a number of transfer model parameters.

  7. Effects of antibacterial agents, levofloxacin and clarithromycin, on aquatic organisms.

    PubMed

    Yamashita, N; Yasojima, M; Nakada, N; Miyajima, K; Komori, K; Suzuki, Y; Tanaka, H

    2006-01-01

    Contamination of surface waters by pharmaceutical chemicals is an emerging environmental problem. This study evaluated the toxic effects of the antibacterial agents levofloxacin (LVFX) and clarithromycin (CAM), which are widely used in Japan, on aquatic organisms. Ecotoxicity tests using a bacterium, alga and crustacean were conducted. Microtox test using a marine fluorescent bacterium showed that LVFX and CAM have no acute toxicity to the bacterium. From the results of the Daphnia immobilisation test, LVFX and CAM did not show acute toxicity to the crustacean. Meanwhile, an algal growth inhibition test revealed that LVFX and CAM have high toxicity to the microalga. The phytotoxicity of CAM was about 100-fold higher than that of LVFX from a comparison of EC50 (median effective concentration) value. From the Daphnia reproduction test, LVFX and CAM also showed chronic toxicity to the crustacean. Concentrations of LVFX and CAM in the aquatic environment were compared with PNEC (predicted no effect concentration) to evaluate the ecological risk. As a result, the ecological risk of LVFX is considered to be low, but that of CAM is higher, suggesting that CAM discharged into an aquatic environment after therapeutic use may affect organisms in the aquatic environment.

  8. How run-of-river operation affects hydropower generation and value.

    PubMed

    Jager, Henriette I; Bevelhimer, Mark S

    2007-12-01

    Regulated rivers in the United States are required to support human water uses while preserving aquatic ecosystems. However, the effectiveness of hydropower license requirements nationwide has not been demonstrated. One requirement that has become more common is "run-of-river" (ROR) operation, which restores a natural flow regime. It is widely believed that ROR requirements (1) are mandated to protect aquatic biota, (2) decrease hydropower generation per unit flow, and (3) decrease energy revenue. We tested these three assumptions by reviewing hydropower projects with license-mandated changes from peaking to ROR operation. We found that ROR operation was often prescribed in states with strong water-quality certification requirements and migratory fish species. Although benefits to aquatic resources were frequently cited, changes were often motivated by other considerations. After controlling for climate, the overall change in annual generation efficiency across projects because of the change in operation was not significant. However, significant decreases were detected at one quarter of individual hydropower projects. As expected, we observed a decrease in flow during peak demand at 7 of 10 projects. At the remaining projects, diurnal fluctuations actually increased because of operation of upstream storage projects. The economic implications of these results, including both producer costs and ecologic benefits, are discussed. We conclude that regional-scale studies of hydropower regulation, such as this one, are long overdue. Public dissemination of flow data, license provisions, and monitoring data by way of on-line access would facilitate regional policy analysis while increasing regulatory transparency and providing feedback to decision makers.

  9. Aquatic models, genomics and chemical risk management.

    PubMed

    Cheng, Keith C; Hinton, David E; Mattingly, Carolyn J; Planchart, Antonio

    2012-01-01

    The 5th Aquatic Animal Models for Human Disease meeting follows four previous meetings (Nairn et al., 2001; Schmale, 2004; Schmale et al., 2007; Hinton et al., 2009) in which advances in aquatic animal models for human disease research were reported, and community discussion of future direction was pursued. At this meeting, discussion at a workshop entitled Bioinformatics and Computational Biology with Web-based Resources (20 September 2010) led to an important conclusion: Aquatic model research using feral and experimental fish, in combination with web-based access to annotated anatomical atlases and toxicological databases, yields data that advance our understanding of human gene function, and can be used to facilitate environmental management and drug development. We propose here that the effects of genes and environment are best appreciated within an anatomical context - the specifically affected cells and organs in the whole animal. We envision the use of automated, whole-animal imaging at cellular resolution and computational morphometry facilitated by high-performance computing and automated entry into toxicological databases, as anchors for genetic and toxicological data, and as connectors between human and model system data. These principles should be applied to both laboratory and feral fish populations, which have been virtually irreplaceable sentinals for environmental contamination that results in human morbidity and mortality. We conclude that automation, database generation, and web-based accessibility, facilitated by genomic/transcriptomic data and high-performance and cloud computing, will potentiate the unique and potentially key roles that aquatic models play in advancing systems biology, drug development, and environmental risk management. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Review on environmental alterations propagating from aquatic to terrestrial ecosystems.

    PubMed

    Schulz, Ralf; Bundschuh, Mirco; Gergs, René; Brühl, Carsten A; Diehl, Dörte; Entling, Martin H; Fahse, Lorenz; Frör, Oliver; Jungkunst, Hermann F; Lorke, Andreas; Schäfer, Ralf B; Schaumann, Gabriele E; Schwenk, Klaus

    2015-12-15

    Terrestrial inputs into freshwater ecosystems are a classical field of environmental science. Resource fluxes (subsidy) from aquatic to terrestrial systems have been less studied, although they are of high ecological relevance particularly for the receiving ecosystem. These fluxes may, however, be impacted by anthropogenically driven alterations modifying structure and functioning of aquatic ecosystems. In this context, we reviewed the peer-reviewed literature for studies addressing the subsidy of terrestrial by aquatic ecosystems with special emphasis on the role that anthropogenic alterations play in this water-land coupling. Our analysis revealed a continuously increasing interest in the coupling of aquatic to terrestrial ecosystems between 1990 and 2014 (total: 661 studies), while the research domains focusing on abiotic (502 studies) and biotic (159 studies) processes are strongly separated. Approximately 35% (abiotic) and 25% (biotic) of the studies focused on the propagation of anthropogenic alterations from the aquatic to the terrestrial system. Among these studies, hydromorphological and hydrological alterations were predominantly assessed, whereas water pollution and invasive species were less frequently investigated. Less than 5% of these studies considered indirect effects in the terrestrial system e.g. via food web responses, as a result of anthropogenic alterations in aquatic ecosystems. Nonetheless, these very few publications indicate far-reaching consequences in the receiving terrestrial ecosystem. For example, bottom-up mediated responses via soil quality can cascade over plant communities up to the level of herbivorous arthropods, while top-down mediated responses via predatory spiders can cascade down to herbivorous arthropods and even plants. Overall, the current state of knowledge calls for an integrated assessment on how these interactions within terrestrial ecosystems are affected by propagation of aquatic ecosystem alterations. To fill

  11. Total petroleum hydrocarbons in edible marine biota from Northern Persian Gulf.

    PubMed

    Nozar, Seyedeh Laili Mohebbi; Pauzi, Mohamad Zakaria; Salarpouri, Ali; Daghooghi, Behnam; Salimizadeh, Maryam

    2015-04-01

    To provide a baseline information for consumer's health, distribution of total petroleum hydrocarbons in 18 edible marine biota species from northern Persian Gulf was evaluated. The samples were purchased from fish market of Hormozgan Province, South of Iran. Marine biota samples included different species with various feeding habits and were analyzed based on ultraviolet florescence spectroscopy. Petroleum hydrocarbons showed narrow variation, ranging from 0.67 to 3.36 μg/g dry weight. The maximum value was observed in silver pomfret. Anchovy and silver pomfret with the highest content of petroleum hydrocarbons were known as good indicator for oil pollution in the studied area. From public health point of view, the detected concentrations for total petroleum hydrocarbons were lower than hazardous guidelines. The results were recorded as background data and information in the studied area; the continuous monitoring of pollutants is recommended, according to the rapid extension of industrial and oily activities in Hormozgan Province.

  12. Redkinian Biota of Macroscopic Fossils from the Northwestern East European Platform (South Ladoga Region)

    NASA Astrophysics Data System (ADS)

    Golubkova, E. Yu.; Kushim, E. A.; Kuznetsov, A. B.; Yanovskii, A. S.; Maslov, A. V.; Shvedov, S. D.; Plotkina, Yu. V.

    2018-03-01

    The stratigraphic distribution of microfossils and macroscopic fossil biota in Vendian deposits of the South Ladoga region (northwestern East European Platform) is analyzed. In the sequence of the Shotkusa- 1 well, three taxonomically heterogeneous microfossil assemblages are distinguished: two of them refer to the Redkinian age (Starorusskaya Fm.) and one to the Kotlinian age (Vasileostrovskaya Fm.). Deposits of the Starorusskaya Fm. contain Redkinian biota of macroscopic fossils, of which the most characteristic representatives are Chuaria circularis, Doushantuophyton lineare, Morania zinkovi, Orbisiana simplex, and Redkinia spinosa. These new findings expand the paleontological characteristics of Upper Vendian deposits, also providing additional criteria for distinguishing the Redkinian horizon in the northwestern East European Platform.

  13. Effects of ultraviolet radiation and contaminant-related stressors on arctic freshwater ecosystems.

    PubMed

    Wrona, Frederick J; Prowse, Terry D; Reist, James D; Hobbie, John E; Lévesque, Lucie M J; Macdonald, Robie W; Vincent, Warwick F

    2006-11-01

    Climate change is likely to act as a multiple stressor, leading to cumulative and/or synergistic impacts on aquatic systems. Projected increases in temperature and corresponding alterations in precipitation regimes will enhance contaminant influxes to aquatic systems, and independently increase the susceptibility of aquatic organisms to contaminant exposure and effects. The consequences for the biota will in most cases be additive (cumulative) and multiplicative (synergistic). The overall result will be higher contaminant loads and biomagnification in aquatic ecosystems. Changes in stratospheric ozone and corresponding ultraviolet radiation regimes are also expected to produce cumulative and/or synergistic effects on aquatic ecosystem structure and function. Reduced ice cover is likely to have a much greater effect on underwater UV radiation exposure than the projected levels of stratospheric ozone depletion. A major increase in UV radiation levels will cause enhanced damage to organisms (biomolecular, cellular, and physiological damage, and alterations in species composition). Allocations of energy and resources by aquatic biota to UV radiation protection will increase, probably decreasing trophic-level productivity. Elemental fluxes will increase via photochemical pathways.

  14. Bisphenol A in the aquatic environment and its endocrine-disruptive effects on aquatic organisms.

    PubMed

    Kang, Jeong-Hun; Asai, Daisuke; Aasi, Daisuke; Katayama, Yoshiki

    2007-01-01

    Bisphenol A [BPA; 2,2-bis(4-hydroxyphenyl)propane], which is mainly used in the production of epoxy resins and polycarbonate plastics, is a known endocrine disruptor and is acutely toxic to aquatic organisms. Due to intensified usage of these products, exposure of organisms to BPA via several routes, such as the environment and food, has increased. The aquatic environment is an important area for the study of BPA. This report reviews the literature concerning contamination routes and degradation of BPA in the aquatic environment and its endocrine-disruptive effects on aquatic organisms.

  15. Methods for Aquatic Resource Assessment

    EPA Science Inventory

    The Methods for Aquatic Resource Assessment (MARA) project consists of three main activities in support of assessing the conditions of the nation’s aquatic resources: 1) scientific support for EPA Office of Water’s national aquatic resource surveys; 2) spatial predications of riv...

  16. The soil biota composition along a progressive succession of secondary vegetation in a karst area.

    PubMed

    Zhao, Jie; Li, Shengping; He, Xunyang; Liu, Lu; Wang, Kelin

    2014-01-01

    Karst ecosystems are fragile and are in many regions degraded by anthropogenic activities. Current management of degraded karst areas focuses on aboveground vegetation succession or recovery and aims at establishing a forest ecosystem. Whether progressive succession of vegetation in karst areas is accompanied by establishment of soil biota is poorly understood. In the present study, soil microbial and nematode communities, as well as soil physico-chemical properties were studied along a progressive succession of secondary vegetation (from grassland to shrubland to forest) in a karst area in southwest China. Microbial biomass, nematode density, ratio of fungal to bacterial biomass, nematode structure index, and nematode enrichment index decreased with the secondary succession in the plant community. Overall, the results indicated a pattern of declines in soil biota abundance and food web complexity that was associated with a decrease in soil pH and a decrease in soil organic carbon content with the progressive secondary succession of the plant community. Our findings suggest that soil biota amendment is necessary during karst ecosystem restoration and establishment and management of grasslands may be feasible in karst areas.

  17. DESIGN OF FIELD STUDIES FOR THE MEASUREMENT OF BAFS AND BSAFS.

    EPA Science Inventory

    Bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs) for aquatic organisms are necessary parameters for assessing the ecological risks of nonpolar organic chemicals in aquatic ecosystems. In designing a field study to measure BAFs and/or BSAFs, one of th...

  18. Impact of trace metals from past mining on the aquatic ecosystem: a multi-proxy approach in the Morvan (France).

    PubMed

    Camizuli, E; Monna, F; Scheifler, R; Amiotte-Suchet, P; Losno, R; Beis, P; Bohard, B; Chateau, C; Alibert, P

    2014-10-01

    This study seeks to determine to what extent trace metals resulting from past mining activities are transferred to the aquatic ecosystem, and whether such trace metals still exert deleterious effects on biota. Concentrations of Cd, Cu, Pb and Zn were measured in streambed sediments, transplanted bryophytes and wild brown trout. This study was conducted at two scales: (i) the entire Morvan Regional Nature Park and (ii) three small watersheds selected for their degree of contamination, based on the presence or absence of past mining sites. The overall quality of streambed sediments was assessed using Sediment Quality Indices (SQIs). According to these standard guidelines, more than 96% of the sediments sampled should not represent a threat to biota. Nonetheless, in watersheds where past mining occurred, SQIs are significantly lower. Transplanted bryophytes at these sites consistently present higher trace metal concentrations. For wild brown trout, the scaled mass and liver indices appear to be negatively correlated with liver Pb concentrations, but there are no obvious relationships between past mining and liver metal concentrations or the developmental instability of specimens. Although the impact of past mining and metallurgical works is apparently not as strong as that usually observed in modern mining sites, it is still traceable. For this reason, past mining sites should be monitored, particularly in protected areas erroneously thought to be free of anthropogenic contamination. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Moving beyond a descriptive aquatic toxicology: the value of biological process and trait information.

    PubMed

    Segner, Helmut

    2011-10-01

    In order to improve the ability to link chemical exposure to toxicological and ecological effects, aquatic toxicology will have to move from observing what chemical concentrations induce adverse effects to more explanatory approaches, that are concepts which build on knowledge of biological processes and pathways leading from exposure to adverse effects, as well as on knowledge on stressor vulnerability as given by the genetic, physiological and ecological (e.g., life history) traits of biota. Developing aquatic toxicology in this direction faces a number of challenges, including (i) taking into account species differences in toxicant responses on the basis of the evolutionarily developed diversity of phenotypic vulnerability to environmental stressors, (ii) utilizing diversified biological response profiles to serve as biological read across for prioritizing chemicals, categorizing them according to modes of action, and for guiding targeted toxicity evaluation; (iii) prediction of ecological consequences of toxic exposure from knowledge of how biological processes and phenotypic traits lead to effect propagation across the levels of biological hierarchy; and (iv) the search for concepts to assess the cumulative impact of multiple stressors. An underlying theme in these challenges is that, in addition to the question of what the chemical does to the biological receptor, we should give increasing emphasis to the question how the biological receptor handles the chemicals, i.e., through which pathways the initial chemical-biological interaction extends to the adverse effects, how this extension is modulated by adaptive or compensatory processes as well as by phenotypic traits of the biological receptor. 2011 Elsevier B.V. All rights reserved.

  20. Influence of salinity and prey presence on the survival of aquatic macroinvertebrates of a freshwater marsh

    USGS Publications Warehouse

    Kang, Sung-Ryong; King, Sammy L.

    2012-01-01

    Salinization of coastal freshwater environments is a global issue. Increased salinity from sea level rise, storm surges, or other mechanisms is common in coastal freshwater marshes of Louisiana, USA. The effects of salinity increases on aquatic macroinvertebrates in these systems have received little attention, despite the importance of aquatic macroinvertebrates for nutrient cycling, biodiversity, and as a food source for vertebrate species. We used microcosm experiments to evaluate the effects of salinity, duration of exposure, and prey availability on the relative survival of dominant aquatic macroinvertebrates (i.e., Procambarus clarkii Girard, Cambarellus puer Hobbs, Libellulidae, Dytiscidae cybister) in a freshwater marsh of southwestern Louisiana. We hypothesized that increased salinity, absence of prey, and increased duration of exposure would decrease survival of aquatic macroinvertebrates and that crustaceans would have higher survival than aquatic insect taxon. Our first hypothesis was only partially supported as only salinity increases combined with prolonged exposure duration affected aquatic macroinvertebrate survival. Furthermore, crustaceans had higher survival than aquatic insects. Salinity stress may cause mortality when acting together with other stressful conditions.

  1. Science: Aquatic Toxicology Matures, Gains Importance.

    ERIC Educational Resources Information Center

    Dagani, Ron

    1980-01-01

    Reviews recent advances in aquatic toxicology, whose major goal is to protect diverse aquatic organisms and whole ecological communities from the dire effects of man-made chemicals. Current legislation is reviewed. Differences in mammalian and aquatic toxicology are listed, and examples of research in aquatic toxicology are discussed. (CS)

  2. RADIATION DOSE ASSESSMENT FOR THE BIOTA OF TERRESTRIAL ECOSYSTEMS IN THE SHORELINE ZONE OF THE CHERNOBYL NUCLEAR POWER PLANT COOLING POND

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Farfan, E.; Jannik, T.

    2011-10-01

    Radiation exposure of the biota in the shoreline area of the Chernobyl Nuclear Power Plant Cooling Pond was assessed to evaluate radiological consequences from the decommissioning of the Cooling Pond. The article addresses studies of radioactive contamination of the terrestrial faunal complex and radionuclide concentration ratios in bodies of small birds, small mammals, amphibians, and reptiles living in the area. The data were used to calculate doses to biota using the ERICA Tool software. Doses from {sup 90}Sr and {sup 137}Cs were calculated using the default parameters of the ERICA Tool and were shown to be consistent with biota dosesmore » calculated from the field data. However, the ERICA dose calculations for plutonium isotopes were much higher (2-5 times for small mammals and 10-14 times for birds) than the doses calculated using the experimental data. Currently, the total doses for the terrestrial biota do not exceed maximum recommended levels. However, if the Cooling Pond is allowed to drawdown naturally and the contaminants of the bottom sediments are exposed and enter the biological cycle, the calculated doses to biota may exceed the maximum recommended values. The study is important in establishing the current exposure conditions such that a baseline exists from which changes can be documented following the lowering of the reservoir water. Additionally, the study provided useful radioecological data on biota concentration ratios for some species that are poorly represented in the literature.« less

  3. Aquatic Pest Control. Manual 99.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Agricultural Experiment Station.

    This training manual provides information needed to meet the minimum EPA standards for certification as a commercial applicator of pesticides in the aquatic pest control category. The text discusses various water use situations; aquatic weed identification; herbicide use and effects; and aquatic insects and their control. (CS)

  4. Fire and fish: A synthesis of observation and experience

    Treesearch

    Bruce Rieman; Robert Gresswell; John Rinne

    2012-01-01

    The effects of wildfire on aquatic systems and fishes occurring in them has been linked to the direct or immediate influence of the fire on water quality and the indirect or subsequent effects on watershed characteristics and processes that influence water quality and quantity, stream channels, and aquatic biota (Gresswell 1999). Early research linking fire and aquatic...

  5. Fisheries and aquatic resources--fish health

    USGS Publications Warehouse

    Panek, Frank

    2008-01-01

    Fish health research at Leetown had its origin in the 1930’s when the Leetown Fish Hatchery and Experiment Station was constructed. In 1978, the National Fish Health Research Laboratory, now a component of the Leetown Science Center, was established to solve emerging and known disease problems affecting fish and other aquatic organisms critical to species restoration programs. Center scientists develop methods for the isolation, detection, and identification of fish pathogens and for prevention and control of fish diseases.

  6. Aquatic sources and sinks for nitrous oxide

    NASA Technical Reports Server (NTRS)

    Elkins, J. W.; Wofsy, S. C.; Mcelroy, M. B.; Kaplan, W. A.; Kolb, C. E.

    1978-01-01

    Data are presented which suggest the complexity of the aquatic nitrogen cycle as it affects N2O. The data are from studies made in the central and south-east tropical regions of the Pacific Ocean and in Chesapeake Bay. The data indicate that oxidation of ammonium and amino nitrogen and nitrification form the principle source for marine N2O. It is estimated that the yearly global yield for oceanic N2O is less than about 10 to the 7th power tons. The consumption of atmospheric N2O by the open ocean has not been evidenced, although data from the south-east tropical Pacific and Chesapeake Bay show the consumption of dissolved N2O in low-oxygen conditions. Preliminary observations have also indicated the consumption of atmospheric N2O by aquatic systems such as freshwater pond and a tidal saltmarsh.

  7. #2) Enantiomer Specific Measurements of Current-use Pesticides in Aquatic Systems

    EPA Science Inventory

    Research has shown that current-use pesticides can enter urban and agricultural watersheds and adversely affect aquatic organisms. A potential cause may be higher concentrations of the more toxic pesticide enantiomer present in the pesticide mixture. The presence of pesticide ena...

  8. Enantiomer Specific Measurements of Current-use Pesticides in Aquatic Systems (#2)

    EPA Science Inventory

    Research has shown that current-use pesticides can enter urban and agricultural watersheds and adversely affect aquatic organisms. A potential cause may be higher concentrations of the more toxic pesticide enantiomer present in the pesticide mixture. The presence of pesticide ena...

  9. Deep and shallow water effects on developing preschoolers' aquatic skills.

    PubMed

    Costa, Aldo M; Marinho, Daniel A; Rocha, Helena; Silva, António J; Barbosa, Tiago M; Ferreira, Sandra S; Martins, Marta

    2012-05-01

    The aim of the study was to assess deep and shallow water teaching methods in swimming lessons for preschool children and identify variations in the basic aquatic skills acquired. The study sample included 32 swimming instructors (16 from deep water programs and 16 from shallow water programs) and 98 preschool children (50 from deep water swimming pool and 48 from shallow water swimming pool). The children were also studied regarding their previous experience in swimming (6, 12 and 18 months or practice). Chi-Square test and Fisher's exact test were used to compare the teaching methodology. A discriminant analysis was conducted with Λ wilk's method to predict under what conditions students are better or worse (aquatic competence). Results suggest that regardless of the non-significant variations found in teaching methods, the water depth can affect aquatic skill acquisition - shallow water lessons seem to impose greater water competence particularly after 6 months of practice. The discriminant function revealed a significant association between groups and all predictors for 6 months of swimming practice (p<0.001). Body position in gliding and leg displacements were the main predictors. For 12 and 18 months of practice, the discriminant function do not revealed any significant association between groups. As a conclusion, it seems that the teaching methodology of aquatic readiness based on deep and shallow water programs for preschoolers is not significantly different. However, shallow water lessons could be preferable for the development of basic aquatic skills.

  10. Deep and Shallow Water Effects on Developing Preschoolers’ Aquatic Skills

    PubMed Central

    Costa, Aldo M.; Marinho, Daniel A.; Rocha, Helena; Silva, António J.; Barbosa, Tiago M.; Ferreira, Sandra S.; Martins, Marta

    2012-01-01

    The aim of the study was to assess deep and shallow water teaching methods in swimming lessons for preschool children and identify variations in the basic aquatic skills acquired. The study sample included 32 swimming instructors (16 from deep water programs and 16 from shallow water programs) and 98 preschool children (50 from deep water swimming pool and 48 from shallow water swimming pool). The children were also studied regarding their previous experience in swimming (6, 12 and 18 months or practice). Chi-Square test and Fisher’s exact test were used to compare the teaching methodology. A discriminant analysis was conducted with Λ wilk’s method to predict under what conditions students are better or worse (aquatic competence). Results suggest that regardless of the non-significant variations found in teaching methods, the water depth can affect aquatic skill acquisition - shallow water lessons seem to impose greater water competence particularly after 6 months of practice. The discriminant function revealed a significant association between groups and all predictors for 6 months of swimming practice (p<0.001). Body position in gliding and leg displacements were the main predictors. For 12 and 18 months of practice, the discriminant function do not revealed any significant association between groups. As a conclusion, it seems that the teaching methodology of aquatic readiness based on deep and shallow water programs for preschoolers is not significantly different. However, shallow water lessons could be preferable for the development of basic aquatic skills. PMID:23487406

  11. Modeling Biota-Sediment Accumulation Factors in fish for AOC habitat restoration projects

    EPA Science Inventory

    We compiled contaminated sediment data for Dioxins and Dioxin Like PCBs for the St. Louis River Area of Concern as part of a health impact assessment for the proposed Kingsbury Bay Grassy Point Habitat Restoration project. To incorporate potential Biota-Sediment Accumulation Fac...

  12. Distribution and bioaccumulation of selenium in aquatic microcosms

    USGS Publications Warehouse

    Besser, John M.; Huckins, James N.; Little, Edward E.; La Point, Thomas W.

    1989-01-01

    Closed-system microcosms were used to study factors affecting the fate of selenium (Se) in aquatic systems. Distribution and bioaccumulation of Se varied among sediment types and Se species. A mixture of dissolved 75Se species (selenate, selenite and selenomethionine) was sorbed more rapidly to fine-textured, highly organic pond sediments than to sandy riverine sediments. Sulfate did not affect the distribution and bioaccumulation of 75Se over the range 80–180 mg SO4 liter−1. When each Se species was labeled separately, selenomethionine was lost from the water column more rapidly than selenate or selenite. Selenium lost from the water column accumulated primarily in sediments, but volatilization was also an important pathway for loss of Se added as selenomethionine. Loss rates of dissolved Se residues were more rapid than rates reported from mesocosm and field studies, suggesting that sediment: water interactions are more important in microcosms than in larger test systems. Daphnids accumulated highest concentrations of Se, followed by periphyton and macrophytes. Selenium added as selenomethionine was bioaccumulated preferentially compared to that added as selenite or selenate. Organoselenium compounds such as selenomethione may thus contribute disproportionately to Se bioaccumulation and toxicity in aquatic organisms.

  13. General Relationships between Abiotic Soil Properties and Soil Biota across Spatial Scales and Different Land-Use Types

    PubMed Central

    Birkhofer, Klaus; Schöning, Ingo; Alt, Fabian; Herold, Nadine; Klarner, Bernhard; Maraun, Mark; Marhan, Sven; Oelmann, Yvonne; Wubet, Tesfaye; Yurkov, Andrey; Begerow, Dominik; Berner, Doreen; Buscot, François; Daniel, Rolf; Diekötter, Tim; Ehnes, Roswitha B.; Erdmann, Georgia; Fischer, Christiane; Foesel, Bärbel; Groh, Janine; Gutknecht, Jessica; Kandeler, Ellen; Lang, Christa; Lohaus, Gertrud; Meyer, Annabel; Nacke, Heiko; Näther, Astrid; Overmann, Jörg; Polle, Andrea; Pollierer, Melanie M.; Scheu, Stefan; Schloter, Michael; Schulze, Ernst-Detlef; Schulze, Waltraud; Weinert, Jan; Weisser, Wolfgang W.; Wolters, Volkmar; Schrumpf, Marion

    2012-01-01

    Very few principles have been unraveled that explain the relationship between soil properties and soil biota across large spatial scales and different land-use types. Here, we seek these general relationships using data from 52 differently managed grassland and forest soils in three study regions spanning a latitudinal gradient in Germany. We hypothesize that, after extraction of variation that is explained by location and land-use type, soil properties still explain significant proportions of variation in the abundance and diversity of soil biota. If the relationships between predictors and soil organisms were analyzed individually for each predictor group, soil properties explained the highest amount of variation in soil biota abundance and diversity, followed by land-use type and sampling location. After extraction of variation that originated from location or land-use, abiotic soil properties explained significant amounts of variation in fungal, meso- and macrofauna, but not in yeast or bacterial biomass or diversity. Nitrate or nitrogen concentration and fungal biomass were positively related, but nitrate concentration was negatively related to the abundances of Collembola and mites and to the myriapod species richness across a range of forest and grassland soils. The species richness of earthworms was positively correlated with clay content of soils independent of sample location and land-use type. Our study indicates that after accounting for heterogeneity resulting from large scale differences among sampling locations and land-use types, soil properties still explain significant proportions of variation in fungal and soil fauna abundance or diversity. However, soil biota was also related to processes that act at larger spatial scales and bacteria or soil yeasts only showed weak relationships to soil properties. We therefore argue that more general relationships between soil properties and soil biota can only be derived from future studies that consider

  14. Aquatic Plants and their Control.

    ERIC Educational Resources Information Center

    Michigan State Dept. of Natural Resources, Lansing.

    Aquatic plants can be divided into two types: algae and macrophytes. The goal of aquatic plant management is to maintain a proper balance of plants within a lake and still retain the lake's recreational and economic importance. Aquatic plant management programs have two phases: long-term management (nutrient control), and short-term management…

  15. Arsenic in the health of ecosystems: spatial distribution in water, sediment and aquatic biota of Pampean streams.

    PubMed

    Rodríguez Castro, M C; Marcó P, L; Ranieri, M C; Vázquez, C; Giorgi, A

    2017-10-07

    A survey of arsenic and phosphorus in Pampean streams of Buenos Aires province was performed. Nitrates and ammonia were also determined. Stream water was sampled as well as stream sediment and filamentous algae. Results show that 32 streams exceeded the arsenic recommended guidelines for human consumption of 10 μg L -1 and six exceeded recommended values for aquatic organisms' protection of 50 μg L -1 . The average concentration found was 36.54 μg L -1 and areas with more concentration of As are located in the southern region of the province, in streams that are tributaries of the Atlantic Ocean. Other regions with high As concentration are the Matanza River tributaries and the Arrecifes River tributaries. No differences of As concentration was found between stream sediments. Also, no seasonal pattern of As concentration was observed in one stream sampled during a year, but a positive correlation between As and the conductivity (p = 0.0002) and pH (p = 0.01) of the streams was found. Also, As bioaccumulation was detected for all the algae sampled, but no correlation between As accumulated and As in the stream water was found. Ammonia levels exceeded recommended guidelines for human consumption in the Argentinean law in 30 streams. The characterization performed in this study provides relevant information on the distribution of arsenic and its origin and mobility.

  16. Interactions between climate change and contaminants.

    PubMed

    Schiedek, Doris; Sundelin, Brita; Readman, James W; Macdonald, Robie W

    2007-12-01

    There is now general consensus that climate change is a global threat and a challenge for the 21st century. More and more information is available demonstrating how increased temperature may affect aquatic ecosystems and living resources or how increased water levels may impact coastal zones and their management. Many ecosystems are also affected by human releases of contaminants, for example from land based sources or the atmosphere, which also may cause severe effects. So far these two important stresses on ecosystems have mainly been discussed independently. The present paper is intended to increase awareness among scientists, coastal zone managers and decision makers that climate change will affect contaminant exposure and toxic effects and that both forms of stress will impact aquatic ecosystems and biota. Based on examples from different ecosystems, we discuss risks anticipated from contaminants in a rapidly changing environment and the research required to understand and predict how on-going and future climate change may alter risks from chemical pollution.

  17. The National Nonindigenous Aquatic Species Database

    USGS Publications Warehouse

    Neilson, Matthew E.; Fuller, Pamela L.

    2012-01-01

    The U.S. Geological Survey (USGS) Nonindigenous Aquatic Species (NAS) Program maintains a database that monitors, records, and analyzes sightings of nonindigenous aquatic plant and animal species throughout the United States. The program is based at the USGS Wetland and Aquatic Research Center in Gainesville, Florida.The initiative to maintain scientific information on nationwide occurrences of nonindigenous aquatic species began with the Aquatic Nuisance Species Task Force, created by Congress in 1990 to provide timely information to natural resource managers. Since then, the NAS database has been a clearinghouse of information for confirmed sightings of nonindigenous, also known as nonnative, aquatic species throughout the Nation. The database is used to produce email alerts, maps, summary graphs, publications, and other information products to support natural resource managers.

  18. SOLAR ULTRAVIOLET RADIATION AND AQUATIC CARBON, NITROGEN, SULFUR AND METALS CYCLES

    EPA Science Inventory

    Solar ultraviolet radiation (290-400 nm) has a wide-ranging impact on biological and chemical processes that affect the cycling of elements in aquatic environments. This chapter uses recent field and laboratory observations along with models to assess these impacts on carbon, nit...

  19. How much Is enough? Minimal responses of water quality and stream biota to partial retrofit stormwater management in a suburban neighborhood

    USGS Publications Warehouse

    Roy, Allison; Rhea, Lee K.; Mayer, Audrey L.; Shuster, William D.; Beaulieu, Jake J.; Hopton, Matthew E.; Morrison, Matthew A.; St. Amand, Ann

    2014-01-01

    Decentralized stormwater management approaches (e.g., biofiltration swales, pervious pavement, green roofs, rain gardens) that capture, detain, infiltrate, and filter runoff are now commonly used to minimize the impacts of stormwater runoff from impervious surfaces on aquatic ecosystems. However, there is little research on the effectiveness of retrofit, parcel-scale stormwater management practices for improving downstream aquatic ecosystem health. A reverse auction was used to encourage homeowners to mitigate stormwater on their property within the suburban, 1.8 km2 Shepherd Creek catchment in Cincinnati, Ohio (USA). In 2007–2008, 165 rain barrels and 81 rain gardens were installed on 30% of the properties in four experimental (treatment) subcatchments, and two additional subcatchments were maintained as controls. At the base of the subcatchments, we sampled monthly baseflow water quality, and seasonal (5×/year) physical habitat, periphyton assemblages, and macroinvertebrate assemblages in the streams for the three years before and after treatment implementation. Given the minor reductions in directly connected impervious area from the rain barrel installations (11.6% to 10.4% in the most impaired subcatchment) and high total impervious levels (13.1% to 19.9% in experimental subcatchments), we expected minor or no responses of water quality and biota to stormwater management. There were trends of increased conductivity, iron, and sulfate for control sites, but no such contemporaneous trends for experimental sites. The minor effects of treatment on streamflow volume and water quality did not translate into changes in biotic health, and the few periphyton and macroinvertebrate responses could be explained by factors not associated with the treatment (e.g., vegetation clearing, drought conditions). Improvement of overall stream health is unlikely without additional treatment of major impervious surfaces (including roads, apartment buildings, and parking lots

  20. How much is enough? Minimal responses of water quality and stream biota to partial retrofit stormwater management in a suburban neighborhood.

    PubMed

    Roy, Allison H; Rhea, Lee K; Mayer, Audrey L; Shuster, William D; Beaulieu, Jake J; Hopton, Matthew E; Morrison, Matthew A; St Amand, Ann

    2014-01-01

    Decentralized stormwater management approaches (e.g., biofiltration swales, pervious pavement, green roofs, rain gardens) that capture, detain, infiltrate, and filter runoff are now commonly used to minimize the impacts of stormwater runoff from impervious surfaces on aquatic ecosystems. However, there is little research on the effectiveness of retrofit, parcel-scale stormwater management practices for improving downstream aquatic ecosystem health. A reverse auction was used to encourage homeowners to mitigate stormwater on their property within the suburban, 1.8 km(2) Shepherd Creek catchment in Cincinnati, Ohio (USA). In 2007-2008, 165 rain barrels and 81 rain gardens were installed on 30% of the properties in four experimental (treatment) subcatchments, and two additional subcatchments were maintained as controls. At the base of the subcatchments, we sampled monthly baseflow water quality, and seasonal (5×/year) physical habitat, periphyton assemblages, and macroinvertebrate assemblages in the streams for the three years before and after treatment implementation. Given the minor reductions in directly connected impervious area from the rain barrel installations (11.6% to 10.4% in the most impaired subcatchment) and high total impervious levels (13.1% to 19.9% in experimental subcatchments), we expected minor or no responses of water quality and biota to stormwater management. There were trends of increased conductivity, iron, and sulfate for control sites, but no such contemporaneous trends for experimental sites. The minor effects of treatment on streamflow volume and water quality did not translate into changes in biotic health, and the few periphyton and macroinvertebrate responses could be explained by factors not associated with the treatment (e.g., vegetation clearing, drought conditions). Improvement of overall stream health is unlikely without additional treatment of major impervious surfaces (including roads, apartment buildings, and parking lots

  1. Aquatic toxicity testing for aquatic life impact assessments and recent scientific advancements

    EPA Science Inventory

    The focus of this presentation is to provide an overview of the use of aquatic toxicity testing for assessing possible impacts to aquatic life and how new scientific approaches are being researched. Toxicity testing of both ambient and effluent monitoring samples will be discusse...

  2. The Soil Biota Composition along a Progressive Succession of Secondary Vegetation in a Karst Area

    PubMed Central

    He, Xunyang; Liu, Lu; Wang, Kelin

    2014-01-01

    Karst ecosystems are fragile and are in many regions degraded by anthropogenic activities. Current management of degraded karst areas focuses on aboveground vegetation succession or recovery and aims at establishing a forest ecosystem. Whether progressive succession of vegetation in karst areas is accompanied by establishment of soil biota is poorly understood. In the present study, soil microbial and nematode communities, as well as soil physico-chemical properties were studied along a progressive succession of secondary vegetation (from grassland to shrubland to forest) in a karst area in southwest China. Microbial biomass, nematode density, ratio of fungal to bacterial biomass, nematode structure index, and nematode enrichment index decreased with the secondary succession in the plant community. Overall, the results indicated a pattern of declines in soil biota abundance and food web complexity that was associated with a decrease in soil pH and a decrease in soil organic carbon content with the progressive secondary succession of the plant community. Our findings suggest that soil biota amendment is necessary during karst ecosystem restoration and establishment and management of grasslands may be feasible in karst areas. PMID:25379741

  3. Mercury concentrations in salmonids from western U.S. National Parks and relationships with age and macrophage aggregates

    USGS Publications Warehouse

    Schwindt, A.R.; Fournie, J.W.; Landers, D.H.; Schreck, C.B.; Kent, M.L.

    2008-01-01

    Mercury accumulation in aquatic foodwebs and its effects on aquatic biota are of growing concern both for the health of the fish and the piscivores that prey upon them. This is of particular concern for western U.S. National Parks because it is known that mountainous and Arctic areas are sinks for some contaminants. The Western Airborne Contaminants Assessment Project seeks, in part, to ascertain mercury concentrations and evaluate effects of contaminants on biota in 14 lakes from 8 National Parks or Preserves. In this paper we report that mercury has accumulated to concentrations in trout that may negatively impact some piscivorous wildlife, indicating potential terrestrial ecosystem effects. Additionally, we show that mercury concentrations increase with age in 4 species of trout, providing evidence of bioaccumulation. Finally, we demonstrate that mercury is associated with tissue damage in the kidney and spleen, as indicated by increases in macrophage aggregates. This finding suggests that mercury, and possibly other contaminants, are negatively affecting the trout that inhabit these remote and protected ecosystems. Our results indicate that mercury is indeed a concern for the U.S. National Parks, from an organismic and potentially an ecosystem perspective. ?? 2008 American Chemical Society.

  4. Aquatic Plant Control Research Program: Literature Review of Economic Valuation of Aquatic Plant Control

    DTIC Science & Technology

    1991-02-01

    200 words) Aquatic plant control is necessary to maintain the flow of benefits for which water resources projects are constructed and operated (e.g...but little work has been performed by the Corps to evaluate the economic benefits resulting from aquatic plant control programs. This report reviewed...the applicability of the project evaluation guidance, Principles and Guidelines (P&G), for the eval- uation of aquatic plant control benefits . It was

  5. Aquatic insect assemblages of man-made permanent ponds, Buenos Aires city, Argentina.

    PubMed

    Fontanarrosa, M S; Collantes, M B; Bachmann, A O

    2013-02-01

    Freshwater habitats are important elements within urban green space and they are endangered by various types of human activity. With the aim to increase the knowledge about species biodiversity in urban ecosystems, we characterised the assemblages of aquatic insects in four permanent man-made ponds in Buenos Aires city (Argentina) during a 1-year period. We recorded 32 species with Sigara spp. (Hemiptera) as the most abundant. The removal of aquatic vegetation from the studied ponds may have affected both the establishment and permanence of the insect community. Swimmers were the dominant group in the studied sites, followed by burrowers and sprawlers, and only a few strictly climbers were collected. Therefore, all sampled ponds were dominated by collectors (principally gatherers), secondarily by predators and only few shredders were detected, which was much affected by the removal of macrophytes. Non-parametric abundance indexes estimated a number of species very close to the observed number in each site. Conversely, the incidence indexes estimated more species because there were many more taxa present only in one sample than those represented by few individual in a sample. Our data provides some insights on the community of man-made ponds that can improve the management of these aquatic urban habitats. Considering that macrophytes affect animal assemblages due to their role as physical structures that increase the complexity or heterogeneity of habitats, they should not be removed by authorities in order to promote biodiversity.

  6. DROUGHT-INDUCED DECLINE OF SUBMERGED AQUATIC VEGETATION IN ESCAMBIA BAY, FL.

    EPA Science Inventory

    Locally, the recent decline of SAV was first noticed in Blackwater Bay, FL by N. Craft of Northwest Florida Aquatic Preserves (personal communication). High salinity persisted throughout the summer and fall of 2000 due to a severe drought that has affected much of the southeast ...

  7. Some aspects of interrelations between fungi and other biota in forest soil.

    PubMed

    Krivtsov, Vladimir; Griffiths, Bryan S; Salmond, Ross; Liddell, Keith; Garside, Adam; Bezginova, Tanya; Thompson, Jacqueline A; Staines, Harry J; Watling, Roy; Palfreyman, John W

    2004-08-01

    Interrelations of fungal mycelium with other soil biota are of paramount importance in forestry and soil ecology. Here we present the results of statistical analysis of a comprehensive data set collected in the first (and the only) British fungus sanctuary over a period of four months. The variables studied included a number of soil properties, bacteria, protozoan flagellates, ciliates and amoebae, microbial and plant feeding nematodes, various microarthropods, and two fungal biomarkers--glomalin and ergosterol. One way ANOVA showed that the dynamics of the microbiota studied was influenced by seasonal changes. Superimposed on these changes, however, was variability due to biological interactions and habitat characteristics. Two fungal biomarkers, ergosterol and glomalin, were differently influenced by other biota and abiotic variables. The results indicate that the dynamics of soil fungi is influenced not only by soil microarthropods, but also by those found in forest litter. The overall outcome, therefore, is likely to be very complex and will depend upon specific conditions of any particular ecosystem.

  8. Importance of the National Petroleum Reserve-Alaska for aquatic birds

    USGS Publications Warehouse

    Bart, Jonathan; Platte, Robert M.; Andres, Brad; Brown, Stephen; Johnson, James A.; Larned, William

    2013-01-01

    We used data from aerial surveys (1992–2010) of >100,000 km2 and ground surveys (1998–2004) of >150 km2 to estimate the density and abundance of birds on the North Slope of Alaska (U.S.A.). In the ground surveys, we used double sampling to estimate detection ratios. We used the aerial survey data to compare densities of birds and Arctic fox (Vulpes lagopus), the major nest predator of birds, on the North Slope, in Prudhoe Bay, and in nearby areas. We partitioned the Prudhoe Bay oil field into 2 × 2 km plots and determined the relation between density of aquatic birds and density of roads, buildings, and other infrastructure in these plots. Abundance and density (birds per square kilometer) of 3 groups of aquatic birds—waterfowl, loons, and grebes; shorebirds; and gulls, terns, and jaegers—were highest in the National Petroleum Reserve–Alaska (NPRA) and lowest in the Arctic National Wildlife Refuge. Six other major wetlands occur in the Arctic regions of Canada and Russia, but the largest population of aquatic birds was in the NPRA. Aquatic birds were concentrated in the northern part of the NPRA. For example, an area that covered 18% of the NPRA included 53% of its aquatic birds. The aerial surveys showed that bird density was not lower and fox density was not higher in Prudhoe Bay than in surrounding areas. Density of infrastructure did not significantly affect bird density for any group of species. Our results establish that the NPRA is one of the most important areas for aquatic birds in the Arctic. Our results and those of others also indicate that oil production, as practiced in Prudhoe Bay, does not necessarily lead to substantial declines in bird density or productivity in or near the developed areas.

  9. How Are Changing Solar Ultraviolet Radiation and Climate Affecting Light-induced Chemical Processes in Aquatic Environments?

    EPA Science Inventory

    Changes in the ozone layer over the past three decades have resulted in increases in solar UV-B radiation (280-315 nm) that reach the surface of aquatic environments. These changes have been accompanied by unprecedented changes in temperature and precipitation patterns around the...

  10. Bioaccumulation of perfluorochemicals in sediments by the aquatic oligochaete Lumbriculus variegatus.

    PubMed

    Higgins, Christopher P; McLeod, Pamela B; MacManus-Spencer, Laura A; Luthy, Richard G

    2007-07-01

    Bioaccumulation of perfluoroalkyl sulfonates, perfluorocarboxylates, and 2-(N-ethylperfluorooctane sulfonamido) acetic acid (N-EtFOSAA) from laboratory-spiked and contaminated field sediments was assessed using the freshwater oligochaete, Lumbriculus variegatus. Semistatic batch experiments were conducted to monitor the biological uptake of these perfluorochemicals (PFCs) over 56 days. The elimination of PFCs was measured as the loss of PFCs in L. variegatus exposed to PFC-spiked sediment for 28 days and then transferred to clean sediment. The resultant data suggest that PFCs in sediments are readily bioavailable and that bioaccumulation from sediments does not continually increase with increasing perfluorocarbon chain length. Perfluorooctane sulfonate (PFOS) and perfluorononanoate were the most bioaccumulative PFCs, as measured by laboratory-based estimated steady-state biota sediment accumulation factors (BSAFs) and BSAFs measured using contaminated field sediments. Elimination rate constants for perfluoroalkyl sulfonates and perfluorocaroboxylates were generally smaller than those previously measured for other organic contaminants. Last, a PFOS precursor, N-EtFOSAA, accumulated in the worm tissues and appeared to undergo biotransformation to PFOS and other PFOS precursors. This suggests that N-EtFOSAA, which has been detected in sediments and sludge often at levels exceeding PFOS, may contribute to the bioaccumulation of PFOS in aquatic organisms.

  11. Exceptional vertebrate biotas from the Triassic of China, and the expansion of marine ecosystems after the Permo-Triassic mass extinction

    NASA Astrophysics Data System (ADS)

    Benton, Michael J.; Zhang, Qiyue; Hu, Shixue; Chen, Zhong-Qiang; Wen, Wen; Liu, Jun; Huang, Jinyuan; Zhou, Changyong; Xie, Tao; Tong, Jinnan; Choo, Brian

    2013-10-01

    The Triassic was a time of turmoil, as life recovered from the most devastating of all mass extinctions, the Permo-Triassic event 252 million years ago. The Triassic marine rock succession of southwest China provides unique documentation of the recovery of marine life through a series of well dated, exceptionally preserved fossil assemblages in the Daye, Guanling, Zhuganpo, and Xiaowa formations. New work shows the richness of the faunas of fishes and reptiles, and that recovery of vertebrate faunas was delayed by harsh environmental conditions and then occurred rapidly in the Anisian. The key faunas of fishes and reptiles come from a limited area in eastern Yunnan and western Guizhou provinces, and these may be dated relative to shared stratigraphic units, and their palaeoenvironments reconstructed. The Luoping and Panxian biotas, both from the Guanling Formation, are dated as Anisian (Pelsonian) on the basis of conodonts and radiometric dates, the former being slightly older than the latter. The Xingyi biota is from the Zhuganpo Formation, and is Ladinian or early Carnian, while the Guanling biota is from the overlying Xiaowa Formation, dated as Carnian. The first three biotas include extensive benthos and burrowing in the sediments, and they were located in restricted basins close to shore. Further, even though the Luoping and Panxian biotas are of similar age, their faunas differ significantly, reflecting perhaps palaeogeographically isolated basins. Between the time of the Xingyi and Guanling biotas, there was a major transgression, and the Guanling biota is entirely different in character from the other three, being dominated by pelagic forms such as large floating crinoids attached to logs, very large ichthyosaurs and thalattosaurs, and pseudoplanktonic bivalves, with no benthos and no burrowing. Phylogenetic study of the fishes and marine reptiles shows apparently explosive diversification among 20 actinopterygian lineages very early in the Early Triassic

  12. Stable isotopes of algae and macroinvertebrates in streams respond to watershed urbanization, inform management goals, and indicate food web relationships

    EPA Science Inventory

    Watershed development and anthropogenic sources of nitrogen are among leading causes of negative impacts to aquatic ecosystems around the world. The δ15N of aquatic biota can be used as indicators of anthropogenic sources of nitrogen enriched in 15N, but this mostly has bee...

  13. COASTAL SUBMERGED VEGETATION: AQUATIC HABITAT RESEARCH

    EPA Science Inventory

    Aquatic vegetation is one of the most widespread and important types of aquatic habitat, in part because of the exceptional productivity of the plants. Aquatic vegetation also strongly influences local physical and chemical habitat conditions of significance to fish and shellfis...

  14. Use of Hyperspectral Remote Sensing to Evaluate Efficacy of Aquatic Plant Management

    USDA-ARS?s Scientific Manuscript database

    Invasive aquatic weeds negatively affect biodiversity, fluvial dynamics, water quality, and water storage and conveyance for a variety of human resource demands. In California’s Sacramento-San Joaquin River Delta one submersed species - Brazilian waterweed (Egeria densa) - and one floating species ...

  15. The effects of aquatic oxygen concentration, body size and respiratory behaviour on the stamina of obligate aquatic (Bufo americanus) and facultative air-breathing (Xenopus laevis and Rana berlandieri) anuran larvae.

    PubMed

    Wassersug, R J; Feder, M E

    1983-07-01

    Larvae of the anurans Rana berlandieri and Xenopus laevis have lungs and can breathe air as well as irrigate buccal and pharyngeal surfaces for aquatic respiration. Larvae of Bufo americanus lack lungs until just before metamorphosis and are obligately aquatic. We examined the relationship between the locomotor stamina (time to fatigue), aquatic oxygen concentration, body size, and respiratory behaviour of swimming larvae of these species, with the following results: Stamina is size-dependent in all three species. Aquatic hypoxia reduces stamina in larvae of all three species, but most conspicuously in Bufo. Breathing air increases stamina in Rana larvae, especially in large animals and under aquatic hypoxia. In contrast to Rana larvae, Xenopus larvae swimming in normoxic water undergo a reduction in stamina when allowed to breathe air. In hypoxic water, aerial respiration moderates the reduction in stamina seen in Xenopus larvae. Branchial irrigation is associated with increased stamina in Xenopus, and is increased under hypoxia and at high swimming velocities. Respiratory demand, buoyancy and the drag associated with branchial irrigation all affect respiratory behaviour in Xenopus larvae. The great amount of interspecific variation in the relationship between respiratory behaviour and stamina reveals the importance of measuring performance directly when attempting to interpret the functional significance of respiratory structures and behaviour.

  16. Aquatics for Disabled Persons.

    ERIC Educational Resources Information Center

    Priest, Louise

    1983-01-01

    Rising energy costs and staff reductions pose problems for those who direct aquatic programs for the disabled. At the same time, aquatics programs for the disabled are increasing in number, broadening in scope, and offering new opportunities for research and development of materials. (PP)

  17. Developmental Aquatics: Assessment and Instructional Programming.

    ERIC Educational Resources Information Center

    Doremus, Wendy A.

    1992-01-01

    This article provides an assessment tool and guidelines for creating instructional programing in aquatic skills development for children with disabilities functioning below levels required for most adapted beginning aquatics programs. It covers individualized goals and objectives, adjustment to the water, and specific aquatic skills. (DB)

  18. Modeling Aquatic Toxicity through Chromatographic Systems.

    PubMed

    Fernández-Pumarega, Alejandro; Amézqueta, Susana; Farré, Sandra; Muñoz-Pascual, Laura; Abraham, Michael H; Fuguet, Elisabet; Rosés, Martí

    2017-08-01

    Environmental risk assessment requires information about the toxicity of the growing number of chemical products coming from different origins that can contaminate water and become toxicants to aquatic species or other living beings via the trophic chain. Direct toxicity measurements using sensitive aquatic species can be carried out but they may become expensive and ethically questionable. Literature refers to the use of chromatographic measurements that correlate to the toxic effect of a compound over a specific aquatic species as an alternative to get toxicity information. In this work, we have studied the similarity in the response of the toxicity to different species and we have selected eight representative aquatic species (including tadpoles, fish, water fleas, protozoan, and bacteria) with known nonspecific toxicity to chemical substances. Next, we have selected four chromatographic systems offering good perspectives for surrogation of the eight selected aquatic systems, and thus prediction of toxicity from the chromatographic measurement. Then toxicity has been correlated to the chromatographic retention factor. Satisfactory correlation results have been obtained to emulate toxicity in five of the selected aquatic species through some of the chromatographic systems. Other aquatic species with similar characteristics to these five representative ones could also be emulated by using the same chromatographic systems. The final aim of this study is to model chemical products toxicity to aquatic species by means of chromatographic systems to reduce in vivo testing.

  19. What areas of functioning are influenced by aquatic physiotherapy? Experiences of parents of children with cerebral palsy.

    PubMed

    Güeita-Rodríguez, Javier; García-Muro, Francisco; Rodríguez-Fernández, Ángel L; Lambeck, Johan; Fernández-de-Las-Peñas, Cesar; Palacios-Ceña, Domingo

    2017-09-21

    To explore the experiences regarding aquatic physiotherapy among parents of children with cerebral palsy and to identify a list of relevant intervention categories for aquatic physiotherapy treatments. We conducted semi-structured interviews and focus groups using the components of the International Classification of Functioning, Disability and Health (ICF) as a frame of reference to explore and code experiences regarding aquatic physiotherapy. A non-probabilistic purposive sampling strategy was used. Content analysis methods and ICF linking processes were used to analyze data. From the parents' perspective (n = 34), both the Body Functions and Activities and Participation components were mainly influenced by aquatic physiotherapy. Also, parents described Environmental Factors acting as barriers affecting progress during therapy. Parents identified a wide range of categories influenced by aquatic physiotherapy. Social and contextual aspects were highlighted, as well as a series of changes related to the illness as a result of treatment.

  20. Paleoclimatic modeling and phylogeography of least killifish, Heterandria formosa: insights into Pleistocene expansion-contraction dynamics and evolutionary history of North American Coastal Plain freshwater biota

    PubMed Central

    2013-01-01

    Background Climatic and sea-level fluctuations throughout the last Pleistocene glacial cycle (~130-0 ka) profoundly influenced present-day distributions and genetic diversity of Northern Hemisphere biotas by forcing range contractions in many species during the glacial advance and allowing expansion following glacial retreat ('expansion-contraction’ model). Evidence for such range dynamics and refugia in the unglaciated Gulf-Atlantic Coastal Plain stems largely from terrestrial species, and aquatic species Pleistocene responses remain relatively uninvestigated. Heterandria formosa, a wide-ranging regional endemic, presents an ideal system to test the expansion-contraction model within this biota. By integrating ecological niche modeling and phylogeography, we infer the Pleistocene history of this livebearing fish (Poeciliidae) and test for several predicted distributional and genetic effects of the last glaciation. Results Paleoclimatic models predicted range contraction to a single southwest Florida peninsula refugium during the Last Glacial Maximum, followed by northward expansion. We inferred spatial-population subdivision into four groups that reflect genetic barriers outside this refuge. Several other features of the genetic data were consistent with predictions derived from an expansion-contraction model: limited intraspecific divergence (e.g. mean mtDNA p-distance = 0.66%); a pattern of mtDNA diversity (mean Hd = 0.934; mean π = 0.007) consistent with rapid, recent population expansion; a lack of mtDNA isolation-by-distance; and clinal variation in allozyme diversity with higher diversity at lower latitudes near the predicted refugium. Statistical tests of mismatch distributions and coalescent simulations of the gene tree lent greater support to a scenario of post-glacial expansion and diversification from a single refugium than to any other model examined (e.g. multiple-refugia scenarios). Conclusions Congruent results from diverse data

  1. Differentiating aquatic plant communities in a eutrophic river using hyperspectral and multispectral remote sensing

    USGS Publications Warehouse

    Tian, Y.Q.; Yu, Q.; Zimmerman, M.J.; Flint, S.; Waldron, M.C.

    2010-01-01

    This study evaluates the efficacy of remote sensing technology to monitor species composition, areal extent and density of aquatic plants (macrophytes and filamentous algae) in impoundments where their presence may violate water-quality standards. Multispectral satellite (IKONOS) images and more than 500 in situ hyperspectral samples were acquired to map aquatic plant distributions. By analyzing field measurements, we created a library of hyperspectral signatures for a variety of aquatic plant species, associations and densities. We also used three vegetation indices. Normalized Difference Vegetation Index (NDVI), near-infrared (NIR)-Green Angle Index (NGAI) and normalized water absorption depth (DH), at wavelengths 554, 680, 820 and 977 nm to differentiate among aquatic plant species composition, areal density and thickness in cases where hyperspectral analysis yielded potentially ambiguous interpretations. We compared the NDVI derived from IKONOS imagery with the in situ, hyperspectral-derived NDVI. The IKONOS-based images were also compared to data obtained through routine visual observations. Our results confirmed that aquatic species composition alters spectral signatures and affects the accuracy of remote sensing of aquatic plant density. The results also demonstrated that the NGAI has apparent advantages in estimating density over the NDVI and the DH. In the feature space of the three indices, 3D scatter plot analysis revealed that hyperspectral data can differentiate several aquatic plant associations. High-resolution multispectral imagery provided useful information to distinguish among biophysical aquatic plant characteristics. Classification analysis indicated that using satellite imagery to assess Lemna coverage yielded an overall agreement of 79% with visual observations and >90% agreement for the densest aquatic plant coverages. Interpretation of biophysical parameters derived from high-resolution satellite or airborne imagery should prove to be a

  2. Bioavailability of cyanide and metal-cyanide mixtures to aquatic life.

    PubMed

    Redman, Aaron; Santore, Robert

    2012-08-01

    Cyanide can be toxic to aquatic organisms, and the U.S. Environmental Protection Agency has developed ambient water-quality criteria to protect aquatic life. Recent work suggests that considering free, rather than total, cyanide provides a more accurate measure of the biological effects of cyanides and provides a basis for water-quality criteria. Aquatic organisms are sensitive to free cyanide, although certain metals can form stable complexes and reduce the amount of free cyanide. As a result, total cyanide is less toxic when complexing metals are present. Cyanide is often present in complex effluents, which requires understanding how other components within these complex effluents can affect cyanide speciation and bioavailability. The authors have developed a model to predict the aqueous speciation of cyanide and have shown that this model can predict the toxicity of metal-cyanide complexes in terms of free cyanide in solutions with varying water chemistry. Toxicity endpoints based on total cyanide ranged over several orders of magnitude for various metal-cyanide mixtures. However, predicted free cyanide concentrations among these same tests described the observed toxicity data to within a factor of 2. Aquatic toxicity can be well-described using free cyanide, and under certain conditions the toxicity was jointly described by free cyanide and elevated levels of bioavailable metals. Copyright © 2012 SETAC.

  3. Photodegradation behaviour of estriol: An insight on natural aquatic organic matter influence.

    PubMed

    Oliveira, Cindy; Lima, Diana L D; Silva, Carla Patrícia; Otero, Marta; Esteves, Valdemar I

    2016-09-01

    Estriol (E3) is one of the steroidal estrogens ubiquitously found in the aquatic environment, photodegradation being an important pathway for the elimination of such endocrine disrupting compounds. However, it is important to understand how environmentally important components present in aquatic matrices, such as organic matter, may affect their photodegradation. The main objective of this work was to investigate the photodegradation of E3 in water, under simulated solar radiation, as well as the effect of humic substances (HS - humic acids (HA), fulvic acids (FA) and XAD-4 fraction) in E3 photodegradation. Moreover, the photodegradation behaviour of E3 when present in different environmental aquatic matrices (fresh, estuarine and waste water samples) was also assessed. Results showed a completely different E3 degradation rate depending on the aquatic matrix. In ultrapure water the half-life obtained was about 50 h, while in presence of HS it varied between 5 and 10 h. Then, half-life times between 1.6 and 9.5 h were determined in environmental samples, in which it was observed that the matrix composition contributed up to 97% for the overall E3 photodegradation. Therefore, E3 photodegradation in the considered aquatic matrices was mostly caused by photosensitizing reactions (indirect photodegradation). Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Seasonal comparison of aquatic macroinvertebrate assemblages in a flooded coastal freshwater marsh

    USGS Publications Warehouse

    Kang, Sung-Ryong; King, Sammy L.

    2013-01-01

    Marsh flooding and drying may be important factors affecting aquatic macroinvertebrate density and distribution in coastal freshwater marshes. Limited availability of water as a result of drying in emergent marsh may decrease density, taxonomic diversity, and taxa richness. The principal objectives of this study are to characterize the seasonal aquatic macroinvertebrate assemblage in a freshwater emergent marsh and compare aquatic macroinvertebrate species composition, density, and taxonomic diversity to that of freshwater marsh ponds. We hypothesize that 1) freshwater emergent marsh has lower seasonal density and taxonomic diversity compared to that of freshwater marsh ponds; and 2) freshwater emergent marsh has lower taxa richness than freshwater marsh ponds. Seasonal aquatic macroinvertebrate density in freshwater emergent marsh ranged from 0 organisms/m2 (summer 2009) to 91.1 ± 20.53 organisms/m2 (mean ± SE; spring 2009). Density in spring was higher than in all other seasons. Taxonomic diversity did not differ and there were no unique species in the freshwater emergent marsh. Our data only partially support our first hypothesis as aquatic macroinvertebrate density and taxonomic diversity between freshwater emergent marsh and ponds did not differ in spring, fall, and winter but ponds supported higher macroinvertebrate densities than freshwater emergent marsh during summer. However, our data did not support our second hypothesis as taxa richness between freshwater emergent marsh and ponds did not statistically differ.

  5. The Effect of Aquatic Intervention on the Gross Motor Function and Aquatic Skills in Children with Cerebral Palsy

    PubMed Central

    Dimitrijević, Lidija; Aleksandrović, Marko; Madić, Dejan; Okičić, Tomislav; Radovanović, Dragan; Daly, Daniel

    2012-01-01

    The objective of this study was to investigate the effect of an aquatic intervention on the gross motor function and aquatic skills of children with cerebral palsy (CP). Twenty-nine children with CP, aged 5 to 14, were recruited. Fourteen children completed an aquatic intervention (EG), and 13 children served as controls (CG). Two participants dropped out due to events (illness) unrelated to the intervention. The aquatic intervention lasted 6 weeks (2 sessions per week at 55 minutes per session) with a follow-up period of 3 weeks. The outcome measures were the Gross Motor Function Measure (GMFM) for motor function and the Water Orientation Test Alyn 2 (WOTA 2) for aquatic skills assessment. A significant improvement was observed in the secondary assessment of GMFM and WOTA 2. In contrast to the aquatic skills improvement, the GMFM change was not maintained at follow-up. Our results indicate that children with CP can improve gross motor function on dry land and aquatic skills with a 6-week water intervention. The intervention period was too short for sustainable improvement in dry-land motor skills after intervention (follow-up), but time was sufficient to achieve sustainable improvements in aquatic skills. PMID:23487257

  6. The effect of aquatic intervention on the gross motor function and aquatic skills in children with cerebral palsy.

    PubMed

    Dimitrijević, Lidija; Aleksandrović, Marko; Madić, Dejan; Okičić, Tomislav; Radovanović, Dragan; Daly, Daniel

    2012-05-01

    The objective of this study was to investigate the effect of an aquatic intervention on the gross motor function and aquatic skills of children with cerebral palsy (CP). Twenty-nine children with CP, aged 5 to 14, were recruited. Fourteen children completed an aquatic intervention (EG), and 13 children served as controls (CG). Two participants dropped out due to events (illness) unrelated to the intervention. The aquatic intervention lasted 6 weeks (2 sessions per week at 55 minutes per session) with a follow-up period of 3 weeks. The outcome measures were the Gross Motor Function Measure (GMFM) for motor function and the Water Orientation Test Alyn 2 (WOTA 2) for aquatic skills assessment. A significant improvement was observed in the secondary assessment of GMFM and WOTA 2. In contrast to the aquatic skills improvement, the GMFM change was not maintained at follow-up. Our results indicate that children with CP can improve gross motor function on dry land and aquatic skills with a 6-week water intervention. The intervention period was too short for sustainable improvement in dry-land motor skills after intervention (follow-up), but time was sufficient to achieve sustainable improvements in aquatic skills.

  7. Careful logging, partial cutting and the protection of terrestrial and aquatic habitats

    Treesearch

    Daniel C. Dey

    1994-01-01

    Stand management activites influence (1) tree growth and quality; (2) stand structure, stocking and composition; (3) wildlife and aquatic habitat quality; and (4) long-term site productivity. The cumulative impacts of stand-level treatments affect ecosystem structure and function at the landscape level.

  8. INTERACTIONS OF SOLAR UV RADIATION AND DISSOLVED ORGANIC MATTER IN AQUATIC ENVIRONMENTS

    EPA Science Inventory

    Changes in the ozone layer over the past two decades have resulted in increases in solar ultraviolet (UV) radiation that reaches the surface of aquatic environments. Recent studies have demonstrated that these UV increases cause changes in photochemical reactions that affect the...

  9. Comprehensive review on phytotechnology: Heavy metals removal by diverse aquatic plants species from wastewater.

    PubMed

    Rezania, Shahabaldin; Taib, Shazwin Mat; Md Din, Mohd Fadhil; Dahalan, Farrah Aini; Kamyab, Hesam

    2016-11-15

    Environmental pollution specifically water pollution is alarming both in the developed and developing countries. Heavy metal contamination of water resources is a critical issue which adversely affects humans, plants and animals. Phytoremediation is a cost-effective remediation technology which able to treat heavy metal polluted sites. This environmental friendly method has been successfully implemented in constructed wetland (CWs) which is able to restore the aquatic biosystem naturally. Nowadays, many aquatic plant species are being investigated to determine their potential and effectiveness for phytoremediation application, especially high growth rate plants i.e. macrophytes. Based on the findings, phytofiltration (rhizofiltration) is the sole method which defined as heavy metals removal from water by aquatic plants. Due to specific morphology and higher growth rate, free-floating plants were more efficient to uptake heavy metals in comparison with submerged and emergent plants. In this review, the potential of wide range of aquatic plant species with main focus on four well known species (hyper-accumulators): Pistia stratiotes, Eicchornia spp., Lemna spp. and Salvinia spp. was investigated. Moreover, we discussed about the history, methods and future prospects in phytoremediation of heavy metals by aquatic plants comprehensively. Copyright © 2016. Published by Elsevier B.V.

  10. MERCURY CONCENTRATIONS IN SALMONIDS FROM WESTERN U.S. NATIONAL PARKS AND RELATIONSHIPS WITH AGE AND MACROPHAGE AGGREGATES

    EPA Science Inventory

    Mercury accumulation in aquatic foodwebs and its effects on aquatic biota are of growing concern both for the health of the fish and the piscivores that prey upon them. This is of particular concern for western U.S. National Parks because it is known that mountainous and Arctic a...

  11. Interactions with soil biota shift from negative to positive when a tree species is moved outside its native range.

    PubMed

    Gundale, Michael J; Kardol, Paul; Nilsson, Marie-Charlotte; Nilsson, Urban; Lucas, Richard W; Wardle, David A

    2014-04-01

    Studies evaluating plant-soil biota interactions in both native and introduced plant ranges are rare, and thus far have lacked robust experimental designs to account for several potential confounding factors. Here, we investigated the effects of soil biota on growth of Pinus contorta, which has been introduced from Canada to Sweden. Using Swedish and Canadian soils, we conducted two glasshouse experiments. The first experiment utilized unsterilized soil from each country, with a full-factorial cross of soil origin, tree provenance, and fertilizer addition. The second experiment utilized gamma-irradiated sterile soil from each country, with a full-factorial cross of soil origin, soil biota inoculation treatments, tree provenance, and fertilizer addition. The first experiment showed higher seedling growth on Swedish soil relative to Canadian soil. The second experiment showed this effect was due to differences in soil biotic communities between the two countries, and occurred independently of all other experimental factors. Our results provide strong evidence that plant interactions with soil biota can shift from negative to positive following introduction to a new region, and are relevant for understanding the success of some exotic forest plantations, and invasive and range-expanding native species. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  12. The influence of the aquatic environment on the control of postural sway.

    PubMed

    Marinho-Buzelli, Andresa R; Rouhani, Hossein; Masani, Kei; Verrier, Mary C; Popovic, Milos R

    2017-01-01

    Balance training in the aquatic environment is often used in rehabilitation practice to improve static and dynamic balance. Although aquatic therapy is widely used in clinical practice, we still lack evidence on how immersion in water actually impacts postural control. We examined how postural sway measured using centre of pressure and trunk acceleration parameters are influenced by the aquatic environment along with the effects of visual information. Our results suggest that the aquatic environment increases postural instability, measured by the centre of pressure parameters in the time-domain. The mean velocity and area were more significantly affected when individuals stood with eyes closed in the aquatic environment. In addition, a more forward posture was assumed in water with eyes closed in comparison to standing on land. In water, the low frequencies of sway were more dominant compared to standing on dry land. Trunk acceleration differed in water and dry land only for the larger upper trunk acceleration in mediolateral direction during standing in water. This finding shows that the study participants potentially resorted to using their upper trunk to compensate for postural instability in mediolateral direction. Only the lower trunk seemed to change acceleration pattern in anteroposterior and mediolateral directions when the eyes were closed, and it did so depending on the environment conditions. The increased postural instability and the change in postural control strategies that the aquatic environment offers may be a beneficial stimulus for improving balance control. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Data Basin Aquatic Center: expanding access to aquatic conservation data, analysis tools, people and practical answers

    NASA Astrophysics Data System (ADS)

    Osborne-Gowey, J.; Strittholt, J.; Bergquist, J.; Ward, B. C.; Sheehan, T.; Comendant, T.; Bachelet, D. M.

    2009-12-01

    The world’s aquatic resources are experiencing anthropogenic pressures on an unprecedented scale and aquatic organisms are experiencing widespread population changes and ecosystem-scale habitat alterations. Climate change is likely to exacerbate these threats, in some cases reducing the range of native North American fishes by 20-100% (depending on the location of the population and the model assumptions). Scientists around the globe are generating large volumes of data that vary in quality, format, supporting documentation, and accessibility. Moreover, diverse models are being run at various temporal and spatial scales as scientists attempt to understand previous (and project future) human impacts to aquatic species and their habitats. Conservation scientists often struggle to synthesize this wealth of information for developing practical on-the-ground management strategies. As a result, the best available science is often not utilized in the decision-making and adaptive management processes. As aquatic conservation problems around the globe become more serious and the demand to solve them grows more urgent, scientists and land-use managers need a new way to bring strategic, science-based, and action-oriented approaches to aquatic conservation. The Conservation Biology Institute (CBI), with partners such as ESRI, is developing an Aquatic Center as part of a dynamic, web-based resource (Data Basin; http: databasin.org) that centralizes usable aquatic datasets and provides analytical tools to visualize, analyze, and communicate findings for practical applications. To illustrate its utility, we present example datasets of varying spatial scales and synthesize multiple studies to arrive at novel solutions to aquatic threats.

  14. PAH related effects on fish in sedimentation ponds for road runoff and potential transfer of PAHs from sediment to biota.

    PubMed

    Grung, Merete; Petersen, Karina; Fjeld, Eirik; Allan, Ian; Christensen, Jan H; Malmqvist, Linus M V; Meland, Sondre; Ranneklev, Sissel

    2016-10-01

    Road runoff is an important source of pollution to the aquatic environment, and sedimentation ponds have been installed to mitigate effects on the aquatic environment. The purpose of this study was to investigate if a) fish from sedimentation ponds were affected by road pollution and; b) the transfer of PAHs from road runoff material to aquatic organisms was substantial. Minnow from a sedimentation pond (Skullerud) near Oslo (Norway) had higher levels of CYP1A enzyme and DNA stand breaks than minnow from the nearby river, but high concentrations of PAH-metabolites in bile revealed that both populations were highly exposed. Principal component analysis revealed that CYP1A and age of fish were correlated, while levels of PAH-metabolites were not correlated to CYP1A or DNA damage. Minnow from a lake un-affected by traffic had much lower levels of PAH-metabolites than the exposed fish, and also an improved condition. The latter results indicate that fish health was affected by road runoff. A closer investigation of PAH levels of the ecosystems of two sedimentation ponds (Skullerud and Vassum) and nearby environments were conducted. The concentration of the 16 EPA PAHs in sediments of the sedimentation ponds were high (1900-4200ngg(-1)), and even higher levels were observed in plants. Principal component analysis of selected ion chromatograms of PAHs showed a clear separation of plants vs. sediments. The plants preferentially accumulated the high molecular PAHs, both from sedimentation ponds with a petrogenic PAH isomer ratio in sediments; and from a lake with pyrogenic PAH isomer ratio in sediments. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Pollution of Nigerian Aquatic Ecosystems by Industrial Effluents: Effects on Fish Productivity

    NASA Astrophysics Data System (ADS)

    Nwagwu, S. N.; Kuyoro, E. O.; Agboola, D. M.; Salau, K. S.; Kuyoro, T. O.

    2016-02-01

    Nigeria is uniquely endowed with vast water resources. The near-shore, estuaries, rivers, lakes and pond all taken together, offer tremendous opportunities for fish production. Globally, water bodies are primary means for disposal of waste especially the effluents from industrial, municipal, sewage and agricultural practices near the water body. Studies carried out in most cities in Nigeria has shown that industrial effluent is one of the main sources of water pollution in Nigeria and less than 10% of industries in Nigeria treat their effluents before discharging them into the water bodies. This effluent can alter the physical, chemical and biological nature of the receiving water body resulting in the death of the inhabiting organisms including fish. Untreated industrial waste discharged into water bodies have resulted in eutrophication of aquatic ecosystem as evidence by substantial algal bloom leading to dissolve oxygen depletion and eventually massive mortality of fish and other organisms. Industries like textile producing factory, paper manufacturing plants, oil refinery, brewery and fermentation factory and metal producing industries discharge their wastes into the aquatic ecosystem. These industrial wastes contain pollutants like acids, heavy metals, oil, cyanide, organic chemicals, pesticides, polychlorinated biphenyls, dioxins etc. Some of these pollutants are carcinogenic, mutagenic and teratogenic while some are poisonous depending on the level of exposure and intake by aquatic organisms and man. These pollutants affect the biological growth and reproduction of fishes in the aquatic ecosystem thereby reducing the amount of captured fishes. Fish and other aquatic lives face total extinction due to destruction of aquatic lives and natural habitats by pollution of water bodies. Effluents and wastes produced by industries should be minimised by using low and non-waste technologies; and effluents should be properly treated before they are discharged into

  16. Aquatic Activities for Youth.

    ERIC Educational Resources Information Center

    Greene, H. David; And Others

    Designed to meet the diverse educational needs of youth groups, this aquatic program consists of eight individual lesson units, each devoted to one aspect of the aquatic world. Unit topics include: fish aquariums; raising earthworms; simulation of coastal planning; entomology and water; rope; calculating stream flow; saltwater aquariums; and fish…

  17. Aquatic species and habitats

    Treesearch

    Danny C. Lee; James R. Sedell; Bruce E. Rieman; Russell F. Thurow; Jack E. Williams

    1998-01-01

    Continuing human activities threaten the highly prized aquatic resources of the interior Columbia basin. Precipitous declines in native species, particularly Pacific salmon, and a large influx of introduced species have radically altered the composition and distribution of native fishes. Fortunately, areas of relatively high aquatic integrity remain, much of it on...

  18. Bottom-up nutrient and top-down fish impacts on insect-mediated mercury flux from aquatic ecosystems.

    PubMed

    Jones, Taylor A; Chumchal, Matthew M; Drenner, Ray W; Timmins, Gabrielle N; Nowlin, Weston H

    2013-03-01

    Methyl mercury (MeHg) is one of the most hazardous contaminants in the environment, adversely affecting the health of wildlife and humans. Recent studies have demonstrated that aquatic insects biotransport MeHg and other contaminants to terrestrial consumers, but the factors that regulate the flux of MeHg out of aquatic ecosystems via emergent insects have not been studied. The authors used experimental mesocosms to test the hypothesis that insect emergence and the associated flux of MeHg from aquatic to terrestrial ecosystems is affected by both bottom-up nutrient effects and top-down fish consumer effects. In the present study, nutrient addition led to an increase in MeHg flux primarily by enhancing the biomass of emerging insects whose tissues were contaminated with MeHg, whereas fish decreased MeHg flux primarily by reducing the biomass of emerging insects. Furthermore, the authors found that these factors are interdependent such that the effects of nutrients are more pronounced when fish are absent, and the effects of fish are more pronounced when nutrient concentrations are high. The present study is the first to demonstrate that the flux of MeHg from aquatic to terrestrial ecosystems is strongly enhanced by bottom-up nutrient effects and diminished by top-down consumer effects. Copyright © 2012 SETAC.

  19. The 2.1 Ga old Francevillian biota: biogenicity, taphonomy and biodiversity.

    PubMed

    El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E; Riboulleau, Armelle; Rollion Bard, Claire; Macchiarelli, Roberto; Ngombi Pemba, Lauriss; Hammarlund, Emma; Meunier, Alain; Moubiya Mouele, Idalina; Benzerara, Karim; Bernard, Sylvain; Boulvais, Philippe; Chaussidon, Marc; Cesari, Christian; Fontaine, Claude; Chi-Fru, Ernest; Garcia Ruiz, Juan Manuel; Gauthier-Lafaye, François; Mazurier, Arnaud; Pierson-Wickmann, Anne Catherine; Rouxel, Olivier; Trentesaux, Alain; Vecoli, Marco; Versteegh, Gerard J M; White, Lee; Whitehouse, Martin; Bekker, Andrey

    2014-01-01

    The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations ∼2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rod-shaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life.

  20. Respiratory control in aquatic insects dictates their vulnerability to global warming

    PubMed Central

    Verberk, Wilco C. E. P.; Bilton, David T.

    2013-01-01

    Forecasting species responses to climatic warming requires knowledge of how temperature impacts may be exacerbated by other environmental stressors, hypoxia being a principal example in aquatic systems. Both stressors could interact directly as temperature affects both oxygen bioavailability and ectotherm oxygen demand. Insufficient oxygen has been shown to limit thermal tolerance in several aquatic ectotherms, although, the generality of this mechanism has been challenged for tracheated arthropods. Comparing species pairs spanning four different insect orders, we demonstrate that oxygen can indeed limit thermal tolerance in tracheates. Species that were poor at regulating oxygen uptake were consistently more vulnerable to the synergistic effects of warming and hypoxia, demonstrating the importance of respiratory control in setting thermal tolerance limits. PMID:23925834

  1. Respiratory control in aquatic insects dictates their vulnerability to global warming.

    PubMed

    Verberk, Wilco C E P; Bilton, David T

    2013-10-23

    Forecasting species responses to climatic warming requires knowledge of how temperature impacts may be exacerbated by other environmental stressors, hypoxia being a principal example in aquatic systems. Both stressors could interact directly as temperature affects both oxygen bioavailability and ectotherm oxygen demand. Insufficient oxygen has been shown to limit thermal tolerance in several aquatic ectotherms, although, the generality of this mechanism has been challenged for tracheated arthropods. Comparing species pairs spanning four different insect orders, we demonstrate that oxygen can indeed limit thermal tolerance in tracheates. Species that were poor at regulating oxygen uptake were consistently more vulnerable to the synergistic effects of warming and hypoxia, demonstrating the importance of respiratory control in setting thermal tolerance limits.

  2. The influence of distinct types of aquatic vegetation on the flow field

    NASA Astrophysics Data System (ADS)

    Valyrakis, Manousos; Barcroft, Stephen; Yagci, Oral

    2014-05-01

    The Sustainable management of fluvial systems dealing with flood prevention, erosion protection and restoration of rivers and estuaries requires implementation of soft/green-engineering methods. In-stream aquatic vegetation can be regarded as one of these as it plays an important role for both river ecology (function) and geomorphology (form). The goal of this research is to offer insight gained from pilot experimental studies on the effects of a number of different elements modeling instream, aquatic vegetation on the local flow field. It is hypothesized that elements of the same effective "blockage" area but of distinct characteristics (structure, porosity and flexibility), will affect both the mean and fluctuating levels of the turbulent flow to a different degree. The above hypothesis is investigated through a set of rigorous set of experimental runs which are appropriately designed to assess the variability between the interaction of aquatic elements and flow, both quantitatively and qualitatively. In this investigation three elements are employed to model aquatic vegetation, namely a rigid cylinder, a porous but rigid structure and a flexible live plant (Cupressus Macrocarpa). Firstly, the flow field downstream each of the mentioned elements was measured under steady uniform flow conditions employing acoustic Doppler velocimetry. Three-dimensional flow velocities downstream the vegetation element are acquired along a measurement grid extending about five-fold the element's diameter. These measurements are analyzed to develop mean velocity and turbulent intensity profiles for all velocity components. A detailed comparison between the obtained results is demonstrative of the validity of the above hypothesis as each of the employed elements affects in a different manner and degree the flow field. Then a flow visualization technique, during which fluorescent dye is injected upstream of the element and images are captured for further analysis and comparison, was

  3. Guest editorial: Aquatic science in the Northwest

    USGS Publications Warehouse

    Sepulveda, Adam; Ray, Andrew M.

    2017-01-01

    In recent years, Northwest Science has seen a significant increase in the number of submissions representing aquatic science. Our region is punctuated by aquatic systems. The current issue in particular, presents a number of new aquatic science contributions. Accordingly, Northwest Science invited the authors of this guest editorial to address the question, why is aquatic science so important in the Northwest?

  4. FACTORS INFLUENCING THE DESIGN OF BIOACCUMULATION FACTOR AND BIOTA-SEDIMENT ACCUMULATION FACTOR FIELD STUDIES

    EPA Science Inventory

    A series of modeling simulations were performed to develop an understanding of the underlying factors and principles involved in developing field sampling designs for measuring bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs. These simulations reveal...

  5. A Source of Terrestrial Organic Carbon to Investigate the Browning of Aquatic Ecosystems

    PubMed Central

    Lennon, Jay T.; Hamilton, Stephen K.; Muscarella, Mario E.; Grandy, A. Stuart; Wickings, Kyle; Jones, Stuart E.

    2013-01-01

    There is growing evidence that terrestrial ecosystems are exporting more dissolved organic carbon (DOC) to aquatic ecosystems than they did just a few decades ago. This “browning” phenomenon will alter the chemistry, physics, and biology of inland water bodies in complex and difficult-to-predict ways. Experiments provide an opportunity to elucidate how browning will affect the stability and functioning of aquatic ecosystems. However, it is challenging to obtain sources of DOC that can be used for manipulations at ecologically relevant scales. In this study, we evaluated a commercially available source of humic substances (“Super Hume”) as an analog for natural sources of terrestrial DOC. Based on chemical characterizations, comparative surveys, and whole-ecosystem manipulations, we found that the physical and chemical properties of Super Hume are similar to those of natural DOC in aquatic and terrestrial ecosystems. For example, Super Hume attenuated solar radiation in ways that will not only influence the physiology of aquatic taxa but also the metabolism of entire ecosystems. Based on its chemical properties (high lignin content, high quinone content, and low C:N and C:P ratios), Super Hume is a fairly recalcitrant, low-quality resource for aquatic consumers. Nevertheless, we demonstrate that Super Hume can subsidize aquatic food webs through 1) the uptake of dissolved organic constituents by microorganisms, and 2) the consumption of particulate fractions by larger organisms (i.e., Daphnia). After discussing some of the caveats of Super Hume, we conclude that commercial sources of humic substances can be used to help address pressing ecological questions concerning the increased export of terrestrial DOC to aquatic ecosystems. PMID:24124511

  6. Occurrence of additive brominated flame retardants in aquatic organisms from Tai Lake and Yangtze River in Eastern China, 2009-2012.

    PubMed

    Su, Guanyong; Saunders, David; Yu, Yijun; Yu, Hongxia; Zhang, Xiaowei; Liu, Hongling; Giesy, John P

    2014-11-01

    Since the phase-out of PBDEs, reports regarding occurrences of these compounds in the environment have become less frequent. To characterize potential influences of the phase-out of PBDEs' on concentrations in the environment, trends in concentrations as a function of time were investigated for two additive brominated flame retardants, PBDEs and HBCDs. Three aquatic species, including shrimp, common carp, and yellow catfish, were collected from Meiliang Bay of Tai Lake, 2009-2012. The analysis of PBDEs in three aquatic organisms has shown a downward-trend in the first three years but a significant upward-trend in the final year. Concentrations of HBCDs have not shown temporal increases in the investigated environments. Concentrations of both PBDEs and HBCDs in the three studied organisms increased as a function of trophic level, which suggested that these additive flame retardants can be biomagnified through the food web of Tai Lake. In accordance with previous publications, PBDE-47 contributed the greatest proportion of ∑PBDEs and had a detection frequency of 100%. α-HBCD was the predominate isomer that contributed to ∑HBCDs. Both β-HBCD and γ-HBCD were likely detected at lesser concentrations than the α-isomer due to differences in bioavailability. Concentrations of ∑PBDEs in the three aquatic organisms from Tai Lake ranged from 1.13 to 97.59 ng g(-1) lipid. These concentrations were generally less than those in biota from other countries, but equal to those found at other locations in China. Specimens from the Yangtze River had greater concentrations of ∑HBCDs (169.6-316.5 ng g(-1) lipid) than those collected at Tai Lake, which were comparatively greater than many reported concentrations in freshwater organisms from other countries. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Remote Sensing of Aquatic Plants.

    DTIC Science & Technology

    1979-10-01

    remote sensing methods for identification and assessment of expanses of aquatic plants. Both materials and techniques are examined for cost effectiveness and capability to sense aquatic plants on both the local and regional scales. Computer simulation of photographic responses was employed; Landsat, high-altitude photography, side-looking airborne radar, and low-altitude photography were examined to determine the capabilities of each for identifying and assessing aquatic plants. Results of the study revealed Landsat to be the most cost effective for regional surveys,

  8. Heterogeneity of soil nutrients and subsurface biota in a dryland ecosystem

    USGS Publications Warehouse

    Housman, D.C.; Yeager, C.M.; Darby, B.J.; Sanford, R.L.; Kuske, C.R.; Neher, D.A.; Belnap, J.

    2007-01-01

    Dryland ecosystems have long been considered to have a highly heterogeneous distribution of nutrients and soil biota, with greater concentrations of both in soils under plants relative to interspace soils. We examined the distribution of soil resources in two plant communities (dominated by either the shrub Coleogyne ramosissima or the grass Stipa hymenoides) at two locations. Interspace soils were covered either by early successional biological soil crusts (BSCs) or by later successional BSCs (dominated by nitrogen (N)-fixing cyanobacteria and lichens). For each of the 8 plant type??crust type??locations, we sampled the stem, dripline, and 3 interspace distances around each of 3 plants. Soil analyses revealed that only available potassium (Kav) and ammonium concentrations were consistently greater under plants (7 of 8 sites and 6 of 8 sites, respectively). Nitrate and iron (Fe) were greater under plants at 4 sites, while all other nutrients were greater under plants at less than 50% of the sites. In contrast, calcium, copper, clay, phosphorus (P), and zinc were often greater in the interspace than under the plants. Soil microbial biomass was always greater under the plant compared to the interspace. The community composition of N-fixing bacteria was highly variable, with no distinguishable patterns among microsites. Bacterivorous nematodes and rotifers were consistently more abundant under plants (8 and 7 sites, respectively), and fungivorous and omnivorous nematodes were greater under plants at 5 of the 8 sites. Abundance of other soil biota was greater under plants at less than 50% of the sites, but highly correlated with the availability of N, P, Kav, and Fe. Unlike other ecosystems, the soil biota was only infrequently correlated with organic matter. Lack of plant-driven heterogeneity in soils of this ecosystem is likely due to (1) interspace soils covered with BSCs, (2) little incorporation of above-ground plant litter into soils, and/or (3) root deployment

  9. The NEON Aquatic Network: Expanding the Availability of Biogeochemical Data

    NASA Astrophysics Data System (ADS)

    Vance, J. M.; Bohall, C.; Fitzgerald, M.; Utz, R.; Parker, S. M.; Roehm, C. L.; Goodman, K. J.; McLaughlin, B.

    2013-12-01

    Aquatic ecosystems are facing unprecedented pressure from climate change and land-use practices. Invasive species, whether plant, animal, insect or microbe present additional threat to aquatic ecosystem services. There are significant scientific challenges to understanding how these forces will interact to affect aquatic ecosystems, as the flow of energy and materials in the environment is driven by multivariate and non-linear biogeochemical cycles. The National Ecological Observatory Network (NEON) will collect and provide observational data across multiple scales. Sites were selected to maximize representation of major North American ecosystems using a multivariate geographic clustering method that partitioned the continental US, AK, HI, and Puerto Rico into 20 eco-climatic domains. The NEON data collection systems and methods are designed to yield standardized, near real-time data subjected to rigorous quality controls prior to public dissemination through an online data portal. NEON will collect data for 30 years to facilitate spatial-temporal analysis of environmental responses and drivers of ecosystem change, ranging from local through continental scales. Here we present the NEON Aquatic Network, a multi-parameter network consisting of a combination of in situ sensor and observational data. This network will provide data to examine biogeochemical, biological, hydrologic and geomorphic metrics at 36 sites, which are a combination of small 1st/2nd order wadeable streams, large rivers and lakes. A typical NEON Aquatic site will host up to two in-stream sensor sets designed to collect near-continuous water quality data (e.g. pH/ORP, temperature, conductivity, dissolved oxygen, CDOM) along with up to 8 shallow groundwater monitoring wells (level, temp., cond.), and a local meteorological station (e.g. 2D wind speed, PAR, barometric pressure, temperature, net radiation). These coupled sensor suites will be complemented by observational data (e.g. water

  10. Challenges and opportunities for managing aquatic mercury pollution in altered landscapes.

    PubMed

    Hsu-Kim, Heileen; Eckley, Chris S; Achá, Dario; Feng, Xinbin; Gilmour, Cynthia C; Jonsson, Sofi; Mitchell, Carl P J

    2018-03-01

    The environmental cycling of mercury (Hg) can be affected by natural and anthropogenic perturbations. Of particular concern is how these disruptions increase mobilization of Hg from sites and alter the formation of monomethylmercury (MeHg), a bioaccumulative form of Hg for humans and wildlife. The scientific community has made significant advances in recent years in understanding the processes contributing to the risk of MeHg in the environment. The objective of this paper is to synthesize the scientific understanding of how Hg cycling in the aquatic environment is influenced by landscape perturbations at the local scale, perturbations that include watershed loadings, deforestation, reservoir and wetland creation, rice production, urbanization, mining and industrial point source pollution, and remediation. We focus on the major challenges associated with each type of alteration, as well as management opportunities that could lessen both MeHg levels in biota and exposure to humans. For example, our understanding of approximate response times to changes in Hg inputs from various sources or landscape alterations could lead to policies that prioritize the avoidance of certain activities in the most vulnerable systems and sequestration of Hg in deep soil and sediment pools. The remediation of Hg pollution from historical mining and other industries is shifting towards in situ technologies that could be less disruptive and less costly than conventional approaches. Contemporary artisanal gold mining has well-documented impacts with respect to Hg; however, significant social and political challenges remain in implementing effective policies to minimize Hg use. Much remains to be learned as we strive towards the meaningful application of our understanding for stakeholders, including communities living near Hg-polluted sites, environmental policy makers, and scientists and engineers tasked with developing watershed management solutions. Site-specific assessments of Me

  11. Assessment of the safety of aquatic animal commodities for international trade: the OIE Aquatic Animal Health code.

    PubMed

    Oidtmann, B; Johnston, C; Klotins, K; Mylrea, G; Van, P T; Cabot, S; Martin, P Rosado; Ababouch, L; Berthe, F

    2013-02-01

    Trading of aquatic animals and aquatic animal products has become increasingly globalized during the last couple of decades. This commodity trade has increased the risk for the spread of aquatic animal pathogens. The World Organisation for Animal Health (OIE) is recognized as the international standard-setting organization for measures relating to international trade in animals and animal products. In this role, OIE has developed the Aquatic Animal Health Code, which provides health measures to be used by competent authorities of importing and exporting countries to avoid the transfer of agents pathogenic for animals or humans, whilst avoiding unjustified sanitary barriers. An OIE ad hoc group developed criteria for assessing the safety of aquatic animals or aquatic animal products for any purpose from a country, zone or compartment not declared free from a given disease 'X'. The criteria were based on the absence of the pathogenic agent in the traded commodity or inactivation of the pathogenic agent by the commercial processing used to produce the commodity. The group also developed criteria to assess the safety of aquatic animals or aquatic animal products for retail trade for human consumption from potentially infected areas. Such commodities were assessed considering the form and presentation of the product, the expected volume of waste tissues generated by the consumer and the likely presence of viable pathogenic agent in the waste. The ad hoc group applied the criteria to commodities listed in the individual disease chapters of the Aquatic Animal Health Code (2008 edition). Revised lists of commodities for which no additional measures should be required by the importing countries regardless of the status for disease X of the exporting country were developed and adopted by the OIE World Assembly of Delegates in May 2011. The rationale of the criteria and their application will be explained and demonstrated using examples. © 2012 Crown Copyright. Reproduced

  12. Cyanobacterial effects in Lake Ludoš, Serbia - Is preservation of a degraded aquatic ecosystem justified?

    PubMed

    Tokodi, Nada; Drobac, Damjana; Meriluoto, Jussi; Lujić, Jelena; Marinović, Zoran; Važić, Tamara; Nybom, Sonja; Simeunović, Jelica; Dulić, Tamara; Lazić, Gospava; Petrović, Tamaš; Vuković-Gačić, Branka; Sunjog, Karolina; Kolarević, Stoimir; Kračun-Kolarević, Margareta; Subakov-Simić, Gordana; Miljanović, Branko; Codd, Geoffrey A; Svirčev, Zorica

    2018-04-20

    Cyanobacteria are present in many aquatic ecosystems in Serbia. Lake Ludoš, a wetland area of international significance and an important habitat for waterbirds, has become the subject of intense research interest because of practically continuous blooming of cyanobacteria. Analyses of water samples indicated a deterioration of ecological condition and water quality, and the presence of toxin-producing cyanobacteria (the most abundant Limnothrix redekei, Pseudanabaena limnetica, Planktothrix agardhii and Microcystis spp.). Furthermore, microcystins were detected in plants and animals from the lake: in macrophyte rhizomes (Phragmites communis, Typha latifolia and Nymphaea elegans), and in the muscle, intestines, kidneys, gonads and gills of fish (Carassius gibelio). Moreover, histopathological deleterious effects (liver, kidney, gills and intestines) and DNA damage (liver and gills) were observed in fish. A potential treatment for the reduction of cyanobacterial populations employing hydrogen peroxide was tested during this study. The treatment was not effective in laboratory tests although further in-lake trials are needed to make final conclusions about the applicability of the method. Based on our observations of the cyanobacterial populations and cyanotoxins in the water, as well as other aquatic organisms and, a survey of historical data on Lake Ludoš, it can be concluded that the lake is continuously in a poor ecological state. Conservation of the lake in order to protect the waterbirds (without urgent control of eutrophication) actually endangers them and the rest of the biota in this wetland habitat, and possibly other ecosystems. Thus, urgent measures for restoration are required, so that the preservation of this Ramsar site would be meaningful. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Standing crops and ecology of aquatic invertebrates in agricultural drainwater ponds in California

    USGS Publications Warehouse

    Euliss, N.H.; Jarvis, R.L.; Gilmer, D.S.

    1991-01-01

    We examined standing crops and ecology of aquatic invertebrates in agricultural drainwater evaporation ponds in California from October 1982 to March 1983 and September 1983 to March 1984. Evaporation ponds supported low diversities but high standing crops of aquatic invertebrates. A water boatman (Trichocorixa reticulata) and a midge (Tanypus grodhausi) were the most abundant invertebrates, constituting 44.9% and 51.4% of total macroinvertebrate biomass. Regression models indicated that of 6 environmental variables measured, only electrical conductivity (EC) and Julian date affected biomass and density of water boatmen. EC was the only significant correlate of midge biomass in evaporation ponds.

  14. Can thiol compounds be used as biomarkers of aquatic ecosystem contamination by cadmium?

    PubMed Central

    Kovářová, Jana; Svobodová, Zdeňka

    2009-01-01

    Due to anthropogenic activities, heavy metals still represent a threat for various trophic levels. If aquatic animals are exposed to heavy metals we can obviously observe considerable toxicity. It is well known that an organism affected by cadmium (Cd) synthesize low molecular mass thiol compounds rich in cysteine (Cys), such as metallothioneins (MT) and glutathione (GSH/GSSG). The aim of this study was to summarize the effect of Cd on level of thiol compounds in aquatic organisms, and evaluate that the concentrations of thiol compounds are effective indicators of Cd water pollution and explain their potential use in biomonitoring applications. PMID:21217850

  15. Non-target effects on aquatic decomposer organisms of imidacloprid as a systemic insecticide to control emerald ash borer in riparian trees.

    PubMed

    Kreutzweiser, David; Good, Kevin; Chartrand, Derek; Scarr, Taylor; Thompson, Dean

    2007-11-01

    Imidacloprid is effective against emerald ash borer when applied as a systemic insecticide. Following stem or soil injections to trees in riparian areas, imidacloprid residues could be indirectly introduced to aquatic systems via leaf fall or leaching. Either route of exposure may affect non-target, aquatic decomposer organisms. Leaves from ash trees treated with imidacloprid at two field rates and an intentionally-high concentration were added to aquatic microcosms. Leaves from trees treated at the two field rates contained imidacloprid concentrations of 0.8-1.3 ppm, and did not significantly affect leaf-shredding insect survival, microbial respiration or microbial decomposition rates. Insect feeding rates were significantly inhibited at foliar concentrations of 1.3 ppm but not at 0.8 ppm. Leaves from intentionally high-dose trees contained concentrations of about 80 ppm, and resulted in 89-91% mortality of leaf-shredding insects, but no adverse effects on microbial respiration and decomposition rates. Imidacloprid applied directly to aquatic microcosms to simulate leaching from soils was at least 10 times more toxic to aquatic insects than the foliar concentrations, with high mortality at 0.13 ppm and significant feeding inhibition at 0.012 ppm.

  16. FACTORS INFLUENCING THE DESIGN OF BIOACCUMULATION FACTOR AND BIOTA-SEDIMENT ACCUMULATION FACTOR FIELD STUDIES

    EPA Science Inventory

    General guidance for designing field studies to measure bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs) is not available. To develop such guidance, a series of modeling simulations were performed to evaluate the underlying factors and principles th...

  17. Importance of the national petroleum reserve-alaska for aquatic birds.

    PubMed

    Bart, Jonathan; Platte, Robert M; Andres, Brad; Brown, Stephen; Johnson, James A; Larned, William

    2013-12-01

    We used data from aerial surveys (1992-2010) of >100,000 km(2) and ground surveys (1998-2004) of >150 km(2) to estimate the density and abundance of birds on the North Slope of Alaska (U.S.A.). In the ground surveys, we used double sampling to estimate detection ratios. We used the aerial survey data to compare densities of birds and Arctic fox (Vulpes lagopus), the major nest predator of birds, on the North Slope, in Prudhoe Bay, and in nearby areas. We partitioned the Prudhoe Bay oil field into 2 × 2 km plots and determined the relation between density of aquatic birds and density of roads, buildings, and other infrastructure in these plots. Abundance and density (birds per square kilometer) of 3 groups of aquatic birds-waterfowl, loons, and grebes; shorebirds; and gulls, terns, and jaegers-were highest in the National Petroleum Reserve-Alaska (NPRA) and lowest in the Arctic National Wildlife Refuge. Six other major wetlands occur in the Arctic regions of Canada and Russia, but the largest population of aquatic birds was in the NPRA. Aquatic birds were concentrated in the northern part of the NPRA. For example, an area that covered 18% of the NPRA included 53% of its aquatic birds. The aerial surveys showed that bird density was not lower and fox density was not higher in Prudhoe Bay than in surrounding areas. Density of infrastructure did not significantly affect bird density for any group of species. Our results establish that the NPRA is one of the most important areas for aquatic birds in the Arctic. Our results and those of others also indicate that oil production, as practiced in Prudhoe Bay, does not necessarily lead to substantial declines in bird density or productivity in or near the developed areas. Prioridades para la Conservación de Aves en el Norte de Alaska. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  18. Microplastics alter composition of fungal communities in aquatic ecosystems.

    PubMed

    Kettner, Marie Therese; Rojas-Jimenez, Keilor; Oberbeckmann, Sonja; Labrenz, Matthias; Grossart, Hans-Peter

    2017-11-01

    Despite increasing concerns about microplastic (MP) pollution in aquatic ecosystems, there is insufficient knowledge on how MP affect fungal communities. In this study, we explored the diversity and community composition of fungi attached to polyethylene (PE) and polystyrene (PS) particles incubated in different aquatic systems in north-east Germany: the Baltic Sea, the River Warnow and a wastewater treatment plant. Based on next generation 18S rRNA gene sequencing, 347 different operational taxonomic units assigned to 81 fungal taxa were identified on PE and PS. The MP-associated communities were distinct from fungal communities in the surrounding water and on the natural substrate wood. They also differed significantly among sampling locations, pointing towards a substrate and location specific fungal colonization. Members of Chytridiomycota, Cryptomycota and Ascomycota dominated the fungal assemblages, suggesting that both parasitic and saprophytic fungi thrive in MP biofilms. Thus, considering the worldwide increasing accumulation of plastic particles as well as the substantial vector potential of MP, especially these fungal taxa might benefit from MP pollution in the aquatic environment with yet unknown impacts on their worldwide distribution, as well as biodiversity and food web dynamics at large. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Aquatic Debris Detection Using Embedded Camera Sensors

    PubMed Central

    Wang, Yong; Wang, Dianhong; Lu, Qian; Luo, Dapeng; Fang, Wu

    2015-01-01

    Aquatic debris monitoring is of great importance to human health, aquatic habitats and water transport. In this paper, we first introduce the prototype of an aquatic sensor node equipped with an embedded camera sensor. Based on this sensing platform, we propose a fast and accurate debris detection algorithm. Our method is specifically designed based on compressive sensing theory to give full consideration to the unique challenges in aquatic environments, such as waves, swaying reflections, and tight energy budget. To upload debris images, we use an efficient sparse recovery algorithm in which only a few linear measurements need to be transmitted for image reconstruction. Besides, we implement the host software and test the debris detection algorithm on realistically deployed aquatic sensor nodes. The experimental results demonstrate that our approach is reliable and feasible for debris detection using camera sensors in aquatic environments. PMID:25647741

  20. Aquatic exercise training for fibromyalgia.

    PubMed

    Bidonde, Julia; Busch, Angela J; Webber, Sandra C; Schachter, Candice L; Danyliw, Adrienne; Overend, Tom J; Richards, Rachel S; Rader, Tamara

    2014-10-28

    Exercise training is commonly recommended for individuals with fibromyalgia. This review examined the effects of supervised group aquatic training programs (led by an instructor). We defined aquatic training as exercising in a pool while standing at waist, chest, or shoulder depth. This review is part of the update of the 'Exercise for treating fibromyalgia syndrome' review first published in 2002, and previously updated in 2007. The objective of this systematic review was to evaluate the benefits and harms of aquatic exercise training in adults with fibromyalgia. We searched The Cochrane Library 2013, Issue 2 (Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Health Technology Assessment Database, NHS Economic Evaluation Database), MEDLINE, EMBASE, CINAHL, PEDro, Dissertation Abstracts, WHO international Clinical Trials Registry Platform, and AMED, as well as other sources (i.e., reference lists from key journals, identified articles, meta-analyses, and reviews of all types of treatment for fibromyalgia) from inception to October 2013. Using Cochrane methods, we screened citations, abstracts, and full-text articles. Subsequently, we identified aquatic exercise training studies. Selection criteria were: a) full-text publication of a randomized controlled trial (RCT) in adults diagnosed with fibromyalgia based on published criteria, and b) between-group data for an aquatic intervention and a control or other intervention. We excluded studies if exercise in water was less than 50% of the full intervention. We independently assessed risk of bias and extracted data (24 outcomes), of which we designated seven as major outcomes: multidimensional function, self reported physical function, pain, stiffness, muscle strength, submaximal cardiorespiratory function, withdrawal rates and adverse effects. We resolved discordance through discussion. We evaluated interventions using mean differences

  1. Aquatic toxicology: fact or fiction?

    PubMed Central

    Macek, K J

    1980-01-01

    A brief history of the development of the field of aquatic toxicology is provided. In order to provide a perspective on the state-of-the-art in aquatic toxicology relative to classical toxicology, the two fields are compared from the standpoint of the type of scientist practicing each field, the respective objectives of each, the forces which drive the activity in each field, and the major advantages and disadvantages accruing to the practitioner of aquatic toxicology as a result of the differences in objectives and driving forces. PMID:6993200

  2. Gradual adaptation of bone structure to aquatic lifestyle in extinct sloths from Peru

    PubMed Central

    Amson, Eli; de Muizon, Christian; Laurin, Michel; Argot, Christine; de Buffrénil, Vivian

    2014-01-01

    Non-pathological densification (osteosclerosis) and swelling (pachyostosis) of bones are the main modifications affecting the skeleton of land vertebrates (tetrapods) that returned to water. However, a precise temporal calibration of the acquisition of such adaptations is still wanting. Here, we assess the timing of such acquisition using the aquatic sloth Thalassocnus, from the Neogene of the Pisco Formation, Peru. This genus is represented by five species occurring in successive vertebrate-bearing horizons of distinct ages. It yields the most detailed data about the gradual acquisition of aquatic adaptations among tetrapods, in displaying increasing osteosclerosis and pachyostosis through time. Such modifications, reflecting a shift in the habitat from terrestrial to aquatic, occurred over a short geological time span (ca 4 Myr). Otherwise, the bones of terrestrial pilosans (sloths and anteaters) are much more compact than the mean mammalian condition, which suggests that the osteosclerosis of Thalassocnus may represent an exaptation. PMID:24621950

  3. AN OVERVIEW OF THE AQUATIC ECOLOGICAL RISKS POSED BY DIOXIN-LIKE CHEMICALS

    EPA Science Inventory

    This seminar will provide a basic overview of how 2,3,7,8-tetrachlorodibenzo-p-dioxin (a.k.a. TCDD or "dioxin") and dioxin-like chemicals (e.g., certain PCBs) bioaccumulate and affect non-human receptors in aquatic food webs; the latest on applications of the toxicity equivalence...

  4. Phytoremediation potential of aquatic macrophyte, Azolla.

    PubMed

    Sood, Anjuli; Uniyal, Perm L; Prasanna, Radha; Ahluwalia, Amrik S

    2012-03-01

    Aquatic macrophytes play an important role in the structural and functional aspects of aquatic ecosystems by altering water movement regimes, providing shelter to fish and aquatic invertebrates, serving as a food source, and altering water quality by regulating oxygen balance, nutrient cycles, and accumulating heavy metals. The ability to hyperaccumulate heavy metals makes them interesting research candidates, especially for the treatment of industrial effluents and sewage waste water. The use of aquatic macrophytes, such as Azolla with hyper accumulating ability is known to be an environmentally friendly option to restore polluted aquatic resources. The present review highlights the phytoaccumulation potential of macrophytes with emphasis on utilization of Azolla as a promising candidate for phytoremediation. The impact of uptake of heavy metals on morphology and metabolic processes of Azolla has also been discussed for a better understanding and utilization of this symbiotic association in the field of phytoremediation.

  5. What's New in Aquatics Training.

    ERIC Educational Resources Information Center

    Ensign, Jim

    1992-01-01

    There are many options for aquatic professionals requiring retraining to stay current and certified. The article describes six aquatics training programs, noting their strong points, common concerns, basic features, standard fees, course lengths, and how other professionals view their services. (SM)

  6. Are endocrine disruptors among the causes of the deterioration of aquatic biodiversity?

    PubMed

    Zhou, Jin; Cai, Zhong-Hua; Zhu, Xiao-Shan

    2010-07-01

    Exposure to environmental pollutants such as endocrine-disrupting compounds (EDCs) is now taken into account to explain partially the biodiversity decline of aquatic ecosystems. Much research has demonstrated that EDCs can adversely affect the endocrine system, reproductive health, and immune function in aquatic species. These toxicological effects include 1) interference with normal hormonal synthesis, release, and transport, 2) impairment of growth, development, and gonadal maturation, and 3) increased sensitivity to environmental stressors. Recent studies also have confirmed that EDCs have carcinogenic and mutagenic potential. In essence, these changes in physiological and biochemical parameters reflect, to some extent, some phenotypic characteristics of the deterioration of aquatic biodiversity. At present, evidence at the molecular level shows that exposure to EDCs can trigger genotoxicity, such as DNA damage, and can reduce genetic diversity. Field studies have also provided more direct evidence that EDCs contribute to the population decrease and biodiversity decline. Evolutionary toxicology and multigenerational toxicity tests have further demonstrated that EDCs can damage an organism's offspring and eventually likely lead to loss of evolutionary potential. Taken together, these results provide some basis for understanding the relationship between variety deterioration and EDC exposure. It is conceivable that there is a causal association between EDC exposure and variety deterioration of aquatic organisms. (c) 2010 SETAC.

  7. AQUATIC ASSESSMENT OF THE CHERNOBYL NUCLEAR ACCIDENT AND ITS REMEDIATION

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Onishi, Yasuo; Kivva, Sergey L.; Zheleznyak, Mark J.

    2007-11-01

    This modeling study evaluated aquatic environment affected by the Chernobyl nuclear accident and the effectiveness of remediation efforts. Study results indicate that radionuclide concentrations in the Pripyat and Dnieper rivers were well above the drinking water limits immediately after the Chernobyl accident, but have decreased significantly in subsequent years due to flashing, burying, and decay. Because high concentrations of 90Sr and 137Cs, the major radionuclides affecting human health through aquatic pathways, are associated with flooding, an earthen dike was constructed along the Pripyat River in its most contaminated floodplain. The dike was successful in reducing the 90Sr influx to themore » river by half. A 100-m-high movable dome called the New Safe Confinement is planned to cover the Chernobyl Shelter (formally called the sarcophagus) that was erected shortly after the accident. The NSC will reduce radionuclide contamination further in these rivers and nearby groundwater; however, even if the Chernobyl Shelter collapses before the NSC is built, the resulting peak concentrations of 90Sr and 137Cs in the Dnieper River would still be below the drinking water limits.« less

  8. Climate change and Southern Ocean ecosystems I: how changes in physical habitats directly affect marine biota.

    PubMed

    Constable, Andrew J; Melbourne-Thomas, Jessica; Corney, Stuart P; Arrigo, Kevin R; Barbraud, Christophe; Barnes, David K A; Bindoff, Nathaniel L; Boyd, Philip W; Brandt, Angelika; Costa, Daniel P; Davidson, Andrew T; Ducklow, Hugh W; Emmerson, Louise; Fukuchi, Mitsuo; Gutt, Julian; Hindell, Mark A; Hofmann, Eileen E; Hosie, Graham W; Iida, Takahiro; Jacob, Sarah; Johnston, Nadine M; Kawaguchi, So; Kokubun, Nobuo; Koubbi, Philippe; Lea, Mary-Anne; Makhado, Azwianewi; Massom, Rob A; Meiners, Klaus; Meredith, Michael P; Murphy, Eugene J; Nicol, Stephen; Reid, Keith; Richerson, Kate; Riddle, Martin J; Rintoul, Stephen R; Smith, Walker O; Southwell, Colin; Stark, Jonathon S; Sumner, Michael; Swadling, Kerrie M; Takahashi, Kunio T; Trathan, Phil N; Welsford, Dirk C; Weimerskirch, Henri; Westwood, Karen J; Wienecke, Barbara C; Wolf-Gladrow, Dieter; Wright, Simon W; Xavier, Jose C; Ziegler, Philippe

    2014-10-01

    Antarctic and Southern Ocean (ASO) marine ecosystems have been changing for at least the last 30 years, including in response to increasing ocean temperatures and changes in the extent and seasonality of sea ice; the magnitude and direction of these changes differ between regions around Antarctica that could see populations of the same species changing differently in different regions. This article reviews current and expected changes in ASO physical habitats in response to climate change. It then reviews how these changes may impact the autecology of marine biota of this polar region: microbes, zooplankton, salps, Antarctic krill, fish, cephalopods, marine mammals, seabirds, and benthos. The general prognosis for ASO marine habitats is for an overall warming and freshening, strengthening of westerly winds, with a potential pole-ward movement of those winds and the frontal systems, and an increase in ocean eddy activity. Many habitat parameters will have regionally specific changes, particularly relating to sea ice characteristics and seasonal dynamics. Lower trophic levels are expected to move south as the ocean conditions in which they are currently found move pole-ward. For Antarctic krill and finfish, the latitudinal breadth of their range will depend on their tolerance of warming oceans and changes to productivity. Ocean acidification is a concern not only for calcifying organisms but also for crustaceans such as Antarctic krill; it is also likely to be the most important change in benthic habitats over the coming century. For marine mammals and birds, the expected changes primarily relate to their flexibility in moving to alternative locations for food and the energetic cost of longer or more complex foraging trips for those that are bound to breeding colonies. Few species are sufficiently well studied to make comprehensive species-specific vulnerability assessments possible. Priorities for future work are discussed. © 2014 John Wiley & Sons Ltd.

  9. Aquatic synthesis for Voyageurs National Park

    USGS Publications Warehouse

    Kallemeyn, Larry A.; Holmberg, Kerry L.; Perry, Jim A.; Odde, Beth Y.

    2003-01-01

    Voyageurs National Park (VOYA), which was established in 1975, contains significant aquatic resources with about 50% of its total area of 883 km2 (341 mi2) consisting of aquatic habitats.  In addition to the Park's 30 named lakes, there are numerous wetlands including hundreds of beaver ponds.  Due to the Park's size and location in the drainage basin, aquatic resources within the Park are particularly susceptible to activities and developments that occur outside its' boundary.  This is particularly true in regard to the water quality and aquatic communities in the four large lakes that comprise 96% of the Park's total lake area of 34,400 ha (133 mi2).  Because most Park activities center on the lakes, particularly the large lakes, resource managers need to have knowledge and understanding of VOYA's aquatic resources to effectively preserve, in an unimpaired condition, the ecological processed, biological and cultural diversity, and history of the northwoods, lakecountry border shared with Canada.

  10. Impact of Monsoon to Aquatic Productivity and Fish Landing at Pesawaran Regency Waters

    NASA Astrophysics Data System (ADS)

    Kunarso; Zainuri, Muhammad; Ario, Raden; Munandar, Bayu; Prayogi, Harmon

    2018-02-01

    Monsoon variability influences the productivity processes in the ocean and has different responses in each waters. Furthermore, variability of marine productivity affects to the fisheries resources fluctuation. This research has conducted using descriptive method to investigate the consequences of monsoon variability to aquatic productivity, sea surface temperature (SST), fish catches, and fish season periods at Pesawaran Regency waters, Lampung. Variability of aquatic productivity was determined based on chlorophyll-a indicator from MODIS satellite images. Monsoon variability was governed based on wind parameters and fish catches from fish landing data of Pesawaran fish market. The result showed that monsoon variability had affected to aquatic productivity, SST, and fish catches at Pesawaran Regency waters. Maximum wind speed and lowest SST occurred twice in a year, December to March and August to October, which the peaks were on January (2.55 m/s of wind speed and 29.66°C of SST) and September (2.44 m/s of wind speed and 29.06°C of SST). Also, Maximum aquatic productivity happened on January to March and July to September, which it was arisen simultaneously with maximum wind speed and the peaks was 0.74 mg/m3 and 0.78 mg/m3, on February and August respectively. The data showed that fish catches decreased along with strong wind speed and low SST. However, when weak wind speed and high SST occurred, fish catches increased. The correlation between Catch per Unit Effort (CPUE) with SST, wind speed, and chlorophyll-a was at value 0.76, -0.67, and -0.70, respectively. The high rate fish catches in Pesawaran emerged on March-May and September-December.

  11. A watershed-based spatially-explicit demonstration of an integrated environmental modeling framework for ecosystem services in the Coal River Basin (WV, USA)

    Treesearch

    John M. Johnston; Mahion C. Barber; Kurt Wolfe; Mike Galvin; Mike Cyterski; Rajbir Parmar; Luis Suarez

    2016-01-01

    We demonstrate a spatially-explicit regional assessment of current condition of aquatic ecoservices in the Coal River Basin (CRB), with limited sensitivity analysis for the atmospheric contaminant mercury. The integrated modeling framework (IMF) forecasts water quality and quantity, habitat suitability for aquatic biota, fish biomasses, population densities, ...

  12. New Rotifer Bioassays for Aquatic Toxicology

    DTIC Science & Technology

    1991-07-01

    Acute toxicity tests using rotifers. II. A freshwater test with Brachionus rubens. Aquatic Toxicology. 14: 81-92. Snell, T. W., B. D. Moffat, C. Janssen...24 hours with a sensitivity comparable to that of other aquatic invertebrates. 1. Standard Freshwater Medium Preparation: Carefully add 96 mg NaHCO3,60...rubens. Aquatic Toxicology. 14: 81-92. US Environmental Protection Agency 1985. Methods for measuring the acute toxicity of effluents to freshwater

  13. Cost analysis of aquatic biomass systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1978-07-25

    A cost analysis of aquatic biomass systems was conducted to provide the U.S. Department of Energy with engineering cost information on which to base decisions in the area of planning and executing research and development programs dealing with aquatic biomass as an alternative energy resource. Calculations show that several hundred 100 square mile aquatic biomass farms, the size selected by DOE staff for this analysis, would be needed to provide meaningful supplies of energy. With this background, specific engineering analyses were conducted on two original design concepts for 100 square mile aquatic biomass energy farms. These systems were an open-oceanmore » system and a land-based system; outstanding experts in all aspects of this project were called upon to participate and provide information in projecting the costs for harvested aquatic biomass for these systems. It was found that the projections of costs for harvested open-ocean biomass, utilizing optimistic assumptions of scientific and engineering design parameters, appear to be above any practical costs to be considered for energy. One of the major limitations is due to the need to provide upwelled sub-surface water containing needed nutrients, for which pumping energy is required. It is concluded from this analysis that large scale land-based aquatic biomass farms may merit development, but perhaps within a much narrower range than heretofore investigated. Aquatic plants which appear to have potential for development as an energy resource are the so-called emersed plants, or angiosperms, including many types of freshwater weeds such as duckweed, Hydrilla, and water hyacinths. It is recommended that substantially greater basic and applied knowledge on these aquatic biomass are needed, especially on growth rates and nutrient requirements.« less

  14. The effects of aquatic trunk exercise on gait and muscle activity in stroke patients: a randomized controlled pilot study.

    PubMed

    Park, Byoung-Sun; Noh, Ji-Woong; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Park, Jaehong; Kim, Junghwan

    2015-11-01

    [Purpose] The purpose of this study was to investigate the relationship between muscle activity and gait function following aquatic trunk exercise in hemiplegic stroke patients. [Subjects and Methods] This study's participants included thirteen hemiplegic patients (ten males and three females). The aquatic therapy consisted of administering concentrative aquatic therapy for four weeks in a therapeutic pool. Gait parameters were measured using a gait analysis system adjusted to each subject's comfortable walking speed. Electromyographic signals were measured for the rectus abdominis, external abdominal oblique, transversus abdominis/internal-abdominal oblique, and erector spine of each patients. [Results] The pre- and post-training performances of the transversus abdominis/internal-abdominal oblique were compared statistically. There was no statistical difference between the patients' pre- and post-training values of maximal voluntary isometric contraction of the rectus abdominis, but the external abdominal oblique values tended to improve. Furthermore, gait factors improved significantly in terms of walking speeds, walking cycles, affected-side stance phases, affected-stride lengths, and stance-phase symmetry indices, respectively. [Conclusion] These results suggest that the trunk exercise during aquatic therapy may in part contribute to clinically relevant improvements in muscle activities and gait parameters.

  15. The effects of aquatic trunk exercise on gait and muscle activity in stroke patients: a randomized controlled pilot study

    PubMed Central

    Park, Byoung-Sun; Noh, Ji-Woong; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Park, Jaehong; Kim, Junghwan

    2015-01-01

    [Purpose] The purpose of this study was to investigate the relationship between muscle activity and gait function following aquatic trunk exercise in hemiplegic stroke patients. [Subjects and Methods] This study’s participants included thirteen hemiplegic patients (ten males and three females). The aquatic therapy consisted of administering concentrative aquatic therapy for four weeks in a therapeutic pool. Gait parameters were measured using a gait analysis system adjusted to each subject’s comfortable walking speed. Electromyographic signals were measured for the rectus abdominis, external abdominal oblique, transversus abdominis/internal-abdominal oblique, and erector spine of each patients. [Results] The pre- and post-training performances of the transversus abdominis/internal-abdominal oblique were compared statistically. There was no statistical difference between the patients’ pre- and post-training values of maximal voluntary isometric contraction of the rectus abdominis, but the external abdominal oblique values tended to improve. Furthermore, gait factors improved significantly in terms of walking speeds, walking cycles, affected-side stance phases, affected-stride lengths, and stance-phase symmetry indices, respectively. [Conclusion] These results suggest that the trunk exercise during aquatic therapy may in part contribute to clinically relevant improvements in muscle activities and gait parameters. PMID:26696736

  16. Prey preferences of aquatic insects: potential implications for the regulation of wetland mosquitoes.

    PubMed

    Saha, N; Aditya, G; Saha, G K

    2014-03-01

    Wetlands are potential sites for mosquito breeding and are thus important in the context of public health. The use of chemical and microbial controls is constrained in wetlands in view of their potential impact on the diverse biota. Biological control using generalist aquatic insects can be effective, provided a preference for mosquito larvae is exhibited. The mosquito prey preferences of water bugs and larvae of odonate species were evaluated using chironomid larvae, fish fingerlings and tadpoles as alternative prey. Manly's selectivity (αi ) values with 95% confidence intervals (CIs) were estimated to judge prey preference patterns. Multivariate analysis of variance (manova) and standardized canonical coefficients were used to test the effects of density on prey selectivity. The αi values indicated a significant preference (P < 0.05) in all of the insect predators tested for mosquito larvae over the alternative prey as a density-dependent function. On a comparative scale, chironomid larvae had the highest impact as alternative prey. In a multiple-prey experiment, predators showed a similar pattern of preference for mosquito larvae over alternative prey, reflecting a significant (P < 0.05) niche overlap. The results suggest that, in a laboratory setting, these insect predators can effectively reduce mosquito density in the presence of multiple alternative prey. © 2013 The Royal Entomological Society.

  17. Connectivity of streams and wetlands to downstream waters: An integrated systems framework

    USGS Publications Warehouse

    Leibowitz, Scott G.; Wigington, Parker J.; Schoefield, Kate A.; Alexander, Laurie C.; Vanderhoof, Melanie; Golden, Heather E.

    2018-01-01

    Interest in connectivity has increased in the aquatic sciences, partly because of its relevance to the Clean Water Act. This paper has two objectives: (1) provide a framework to understand hydrological, chemical, and biological connectivity, focusing on how headwater streams and wetlands connect to and contribute to rivers; and (2) briefly review methods to quantify hydrological and chemical connectivity. Streams and wetlands affect river structure and function by altering material and biological fluxes to the river; this depends on two factors: (1) functions within streams and wetlands that affect material fluxes; and (2) connectivity (or isolation) from streams and wetlands to rivers that allows (or prevents) material transport between systems. Connectivity can be described in terms of frequency, magnitude, duration, timing, and rate of change. It results from physical characteristics of a system, e.g., climate, soils, geology, topography, and the spatial distribution of aquatic components. Biological connectivity is also affected by traits and behavior of the biota. Connectivity can be altered by human impacts, often in complex ways. Because of variability in these factors, connectivity is not constant but varies over time and space. Connectivity can be quantified with field‐based methods, modeling, and remote sensing. Further studies using these methods are needed to classify and quantify connectivity of aquatic ecosystems and to understand how impacts affect connectivity.

  18. Meta-Analysis of the Copper, Zinc, and Cadmium Absorption Capacities of Aquatic Plants in Heavy Metal-Polluted Water.

    PubMed

    Li, Jing; Yu, Haixin; Luan, Yaning

    2015-11-26

    The use of aquatic plants for phytoremediation is an important method for restoring polluted ecosystems. We sought to analyze the capacity of different aquatic plant species to absorb heavy metals and to summarize available relevant scientific data on this topic. We present a meta-analysis of Cu, Zn, and Cd absorption capacities of aquatic plants to provide a scientific basis for the selection of aquatic plants suitable for remediation of heavy-metal pollution. Plants from the Gramineae, Pontederiaceae, Ceratophyllaceae, Typhaceae and Haloragaceae showed relatively strong abilities to absorb these metals. The ability of a particular plant species to absorb a given metal was strongly correlated with its ability to absorb the other metals. However, the absorption abilities varied with the plant organ, with the following trend: roots > stems > leaves. The pH of the water and the life habits of aquatic plants (submerged and emerged) also affect the plant's ability to absorb elements. Acidic water aids the uptake of heavy metals by plants. The correlation observed between element concentrations in plants with different aquatic life habits suggested that the enrichment mechanism is related to the surface area of the plant exposed to water. We argue that this meta-analysis would aid the selection of aquatic plants suitable for heavy-metal absorption from polluted waters.

  19. The Occurrence and Diversity of Waterborne Fungi in African Aquatic Systems: Their Impact on Water Quality and Human Health.

    PubMed

    Magwaza, Nontokozo M; Nxumalo, Edward N; Mamba, Bhekie B; Msagati, Titus A M

    2017-05-20

    Currently, there is a worldwide growing interest in the occurrence and diversity of fungi and their secondary metabolites in aquatic systems, especially concerning their role in water quality and human health. However, this concern is hampered by the scant information that is available in the literature about aquatic fungi and how they affect water quality. There are only few published reports that link certain species of aquatic fungi to human health. The common aquatic fungal species that have been reported so far in African aquatic systems belong to the hyphomycetes kingdom. This paper thus aims to survey the information about the occurrence and factors that control the distribution of different species of fungi in African aquatic systems, as well as their effect on water quality and the possible metabolic pathways that lead to the formation of toxic secondary metabolites that are responsible for the deterioration of water quality. This review will also investigate the analytical and bioanalytical procedures that have been reported for the identification of different species of waterborne fungi and their secondary metabolites.

  20. The Occurrence and Diversity of Waterborne Fungi in African Aquatic Systems: Their Impact on Water Quality and Human Health

    PubMed Central

    Magwaza, Nontokozo M.; Nxumalo, Edward N.; Mamba, Bhekie B.; Msagati, Titus A. M.

    2017-01-01

    Currently, there is a worldwide growing interest in the occurrence and diversity of fungi and their secondary metabolites in aquatic systems, especially concerning their role in water quality and human health. However, this concern is hampered by the scant information that is available in the literature about aquatic fungi and how they affect water quality. There are only few published reports that link certain species of aquatic fungi to human health. The common aquatic fungal species that have been reported so far in African aquatic systems belong to the hyphomycetes kingdom. This paper thus aims to survey the information about the occurrence and factors that control the distribution of different species of fungi in African aquatic systems, as well as their effect on water quality and the possible metabolic pathways that lead to the formation of toxic secondary metabolites that are responsible for the deterioration of water quality. This review will also investigate the analytical and bioanalytical procedures that have been reported for the identification of different species of waterborne fungi and their secondary metabolites. PMID:28531124

  1. Effect of emergent aquatic insects on bat foraging in a riparian forest.

    PubMed

    Fukui, Dai; Murakami, Masashi; Nakano, Shigeru; Aoi, Toshiki

    2006-11-01

    1. Riparian zones serve several ecological functions for bats. They provide a source of prey and likely provide favourable structural habitats and shelter from predators. Many studies have shown that bats use the space above streams, ponds or riparian vegetation as feeding habitat. These studies, however, have never distinguished between the effects of habitat structure and prey availability on the foraging activities of bats. Such effects can only be distinguished by an experimental approach. We predicted that bat activity along a stream is influenced by the number of emerged aquatic insects. 2. We evaluated the response of terrestrial consumers, insectivorous bats, to changes in the abundance of emergent aquatic insects by conducting a manipulative field experiment. In a deciduous riparian forest in Japan, aquatic insect flux from the stream to the riparian zone was controlled with an insect-proof cover over a 1.2 km stream reach. 3. We estimated the abundance of emergent aquatic and flying terrestrial arthropods near the treatment and control reaches using Malaise traps. The foraging activity of bats was evaluated in both treatment and control reaches using ultrasonic detectors. 4. The insect-proof cover effectively reduced the flux of emergent aquatic insects to the riparian zone adjacent to the treatment reach. Adjacent to the control reach, adult aquatic insect biomass was highest in spring, and then decreased gradually. Terrestrial insect biomass increased gradually during the summer at both treatment and control reaches. 5. Foraging activity of bats was correlated with insect abundance. In spring, foraging activity of bats at the control reach was significantly greater than at the treatment reach, and increased at both sites with increasing terrestrial insect abundance. 6. Our result suggests that the flux of aquatic insects emerging from streams is one of the most important factors affecting the distribution of riparian-foraging bats. As is the case with

  2. LINKING STORMFLOW HYDROLOGY AND BIOTA IN SUBURBAN STREAMS

    EPA Science Inventory

    Suburban land development has been found to alter the hydrology of landscapes, changing streamflow transient behavior, which may contribute to the typical negative impacts of development on aquatic ecosystems. The linkages between residential development, hydrologic response, and...

  3. Are aliens threatening European aquatic coastal ecosystems?

    NASA Astrophysics Data System (ADS)

    Reise, Karsten; Olenin, Sergej; Thieltges, David W.

    2006-05-01

    Inshore waters of European coasts have accumulated a high share of non-indigenous species, where a changeable palaeoenvironment has caused low diversity in indigenous biota. Also strongly transformed modern coastal ecosystems seem to assimilate whatever species have been introduced and tolerate the physical regime. Adding non-native species does not have any directional predetermined effects on recipient coastal ecosystems. The status of being a non-native rather refers to a position in evolutionary history than qualify as an ecological category with distinct and consistent properties. Effects of invaders vary between habitats and with the phase of invasion and also with shifting ambient conditions. Although aliens accelerate change in European coastal biota, we found no evidence that they generally impair biodiversity and ecosystem functioning. More often, invaders expand ecosystem functioning by adding new ecological traits, intensifying existing ones and increasing functional redundancy.

  4. Warmer winters modulate life history and energy storage but do not affect sensitivity to a widespread pesticide in an aquatic insect.

    PubMed

    Arambourou, Hélène; Stoks, Robby

    2015-10-01

    Despite the increased attention for the effects of pesticides under global warming no studies tested how winter warming affects subsequent sensitivity to pesticides. Winter warming is expected to cause delayed negative effects when it increases metabolic rates and thereby depletes energy reserves. Using a common-garden experiment, we investigated the combined effect of a 4 °C increase in winter temperature and subsequent exposure to chlorpyrifos in the aquatic larvae of replicated low- and high-latitude European populations of the damselfly Ischnura elegans. The warmer winter (8 °C) resulted in a higher winter survival and higher growth rates compared to the cold winter (4 °C) commonly experienced by European high-latitude populations. Low-latitude populations were better at coping with the warmer winter, indicating thermal adaptation to the local winter temperatures. Subsequent chlorpyrifos exposure at 20 °C induced strong negative effects on survival, growth rate, lipid content and acetylcholinesterase activity while phenoloxidase activity increased. These pesticide effects were not affected by winter warming. Our results suggest that for species where winter warming has positive effects on life history, no delayed effects on the sensitivity to subsequent pesticide exposure should be expected. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. How Much Is Enough? Minimal Responses of Water Quality and Stream Biota to Partial Retrofit Stormwater Management in a Suburban Neighborhood

    PubMed Central

    Roy, Allison H.; Rhea, Lee K.; Mayer, Audrey L.; Shuster, William D.; Beaulieu, Jake J.; Hopton, Matthew E.; Morrison, Matthew A.; St. Amand, Ann

    2014-01-01

    Decentralized stormwater management approaches (e.g., biofiltration swales, pervious pavement, green roofs, rain gardens) that capture, detain, infiltrate, and filter runoff are now commonly used to minimize the impacts of stormwater runoff from impervious surfaces on aquatic ecosystems. However, there is little research on the effectiveness of retrofit, parcel-scale stormwater management practices for improving downstream aquatic ecosystem health. A reverse auction was used to encourage homeowners to mitigate stormwater on their property within the suburban, 1.8 km2 Shepherd Creek catchment in Cincinnati, Ohio (USA). In 2007–2008, 165 rain barrels and 81 rain gardens were installed on 30% of the properties in four experimental (treatment) subcatchments, and two additional subcatchments were maintained as controls. At the base of the subcatchments, we sampled monthly baseflow water quality, and seasonal (5×/year) physical habitat, periphyton assemblages, and macroinvertebrate assemblages in the streams for the three years before and after treatment implementation. Given the minor reductions in directly connected impervious area from the rain barrel installations (11.6% to 10.4% in the most impaired subcatchment) and high total impervious levels (13.1% to 19.9% in experimental subcatchments), we expected minor or no responses of water quality and biota to stormwater management. There were trends of increased conductivity, iron, and sulfate for control sites, but no such contemporaneous trends for experimental sites. The minor effects of treatment on streamflow volume and water quality did not translate into changes in biotic health, and the few periphyton and macroinvertebrate responses could be explained by factors not associated with the treatment (e.g., vegetation clearing, drought conditions). Improvement of overall stream health is unlikely without additional treatment of major impervious surfaces (including roads, apartment buildings, and parking lots

  6. Tropical dermatology: marine and aquatic dermatology.

    PubMed

    Haddad, Vidal; Lupi, Omar; Lonza, Juan Pedro; Tyring, Stephen K

    2009-11-01

    Dermatoses caused by marine organisms are frequently seen in dermatology clinics worldwide. Cutaneous injuries after exposure to marine environments include bacterial and fungal infections and lesions caused by aquatic plants and protists. Some of these diseases are well known by dermatologists, such as Vibrio vulnificus septicemia and erysipeloid, but others are uncommon, such as envenomation caused by ingestion or contact with certain dinoflagellates or cyanobacteria, which are associated with rashes that can begin within minutes after exposure. Many marine/aquatic invertebrates, such as sponges, cnidarians, echinoderms, crustaceans, and mollusks, are associated with different kinds of dermatologic lesions that can vary from irritant or allergic contact dermatitis to physical trauma and envenomations. These cutaneous lesions may result in mild local reactions or can be associated with severe systemic reactions. Invertebrate animals, such as cnidarians, sea urchins, and worms, and aquatic vertebrates, such as venomous fishes and stingrays, are commonly associated with skin lesions in many countries, where they can constitute occupational dermatoses among fishermen and scuba divers, but they can also be observed among persons who contact these animals in kitchens or beaches. The presence of unusual lesions, a recent travel history, and/or a report of contact with an aquatic environment (including ownership of a marine or freshwater aquarium) should alert the dermatologist to the etiology of the cutaneous problems. After completing this learning activity, participants should be able to recognize the cutaneous manifestations of marine/aquatic infections, bites, stings, and wounds, etc., treat the cutaneous manifestations of marine/aquatic injuries, and help prevent marine/aquatic injuries.

  7. Aquatic plants for removal of mevinphos from the aquatic environment

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.

    1975-01-01

    Fragrant waterlily (Nymphaea odorata, Ait.), joint-grass (Paspalum distichum L.), and rush (Juncus repens, Michx.) were used to evaluate the effectiveness of vascular aquatic plants in removing the insecticide mevinphos (dimethyl-1-carbomethoxy-1propen-2-yl phosphate) from waters contaminated with this chemical. The emersed aquatic plants fragrant waterlily and joint-grass removed 87 and 93 ppm of mevinphos from water test systems in less than 2 weeks without apparent damage to the plants; whereas rush, a submersed plant, removed less insecticide than the water-soil controls. Water-soil control still contained toxic levels of this insecticide, as demonstrated by fish bioassay studies, after 35 days.

  8. Climate change, fish, and aquatic habitat in the Blue Mountains [Chapter 5

    Treesearch

    Daniel J. Isaak; Katherine Ramsey; John C. Chatel; Deborah L. Konnoff; Robert A. Gecy; Dona Horan

    2017-01-01

    National Forest System lands in the Blue Mountains region support a diversity of important native aquatic species that will be affected by climate change. As part of the Blue Mountains Adaptation Partnership, four of these species (spring Chinook salmon (Oncorhynchus tshawytscha Walbaum in Artedi), bull trout (Salvelinus confluentus Suckley), summer steelhead (O....

  9. Effects of multi-scale environmental characteristics on agricultural stream biota in eastern Wisconsin

    USGS Publications Warehouse

    Fitzpatrick, F.A.; Scudder, B.C.; Lenz, B.N.; Sullivan, D.J.

    2001-01-01

    The U.S. Geological Survey examined 25 agricultural streams in eastern Wisconsin to determine relations between fish, invertebrate, and algal metrics and multiple spatial scales of land cover, geologic setting, hydrologic, aquatic habitat, and water chemistry data. Spearman correlation and redundancy analyses were used to examine relations among biotic metrics and environmental characteristics. Riparian vegetation, geologic, and hydrologic conditions affected the response of biotic metrics to watershed agricultural land cover but the relations were aquatic assemblage dependent. It was difficult to separate the interrelated effects of geologic setting, watershed and buffer land cover, and base flow. Watershed and buffer land cover, geologic setting, reach riparian vegetation width, and stream size affected the fish IBI, invertebrate diversity, diatom IBI, and number of algal taxa; however, the invertebrate FBI, percentage of EPT, and the diatom pollution index were more influenced by nutrient concentrations and flow variability. Fish IBI scores seemed most sensitive to land cover in the entire stream network buffer, more so than watershed-scale land cover and segment or reach riparian vegetation width. All but one stream with more than approximately 10 percent buffer agriculture had fish IBI scores of fair or poor. In general, the invertebrate and algal metrics used in this study were not as sensitive to land cover effects as fish metrics. Some of the reach-scale characteristics, such as width/depth ratios, velocity, and bank stability, could be related to watershed influences of both land cover and geologic setting. The Wisconsin habitat index was related to watershed geologic setting, watershed and buffer land cover, riparian vegetation width, and base flow, and appeared to be a good indicator of stream quality. Results from this study emphasize the value of using more than one or two biotic metrics to assess water quality and the importance of environmental

  10. Protection Goals for Aquatic Plants

    EPA Science Inventory

    Someone once said plants are the ugly stepchildren of the toxicological world. This was not out of lack of respect for plants, but rather reflected the common assumption that aquatic plants were less sensitive than aquatic fauna to chemicals. We now know this is not a valid gener...

  11. New evidence suggests pyroclastic flows are responsible for the remarkable preservation of the Jehol biota

    NASA Astrophysics Data System (ADS)

    Jiang, Baoyu; Harlow, George E.; Wohletz, Kenneth; Zhou, Zhonghe; Meng, Jin

    2014-02-01

    The lower Cretaceous Yixian and Jiufotang formations contain numerous exceptionally well-preserved invertebrate, vertebrate and plant fossils that comprise the Jehol Biota. Freshwater and terrestrial fossils of the biota usually occur together within some horizons and have been interpreted as deposits of mass mortality events. The nature of the events and the mechanisms behind the exceptional preservation of the fossils, however, are poorly understood. Here, after examining and analysing sediments and residual fossils from several key horizons, we postulate that the causal events were mainly phreatomagmatic eruptions. Pyroclastic density currents were probably responsible for the major causalities and for transporting the bulk of the terrestrial vertebrates from different habitats, such as lizards, birds, non-avian dinosaurs and mammals, into lacustrine environments for burial. Terrestrial vertebrate carcasses transported by and sealed within the pyroclastic flows were clearly preserved as exceptional fossils through this process.

  12. Biota: Providing Often-overlooked Connections among Freshwater Systems

    EPA Science Inventory

    When we think about connections in and among aquatic systems, we typically envision clear headwater streams flowing into downstream rivers, river floodwaters spilling out onto adjacent floodplains, or groundwater connecting wetlands to lakes to streams. However, there is another ...

  13. Colloids as a sink for certain pharmaceuticals in the aquatic environment.

    PubMed

    Maskaoui, Khalid; Zhou, John L

    2010-05-01

    filtrate (observed partition coefficients, Kobsp, Kobsoc), between SPM and soluble phase (intrinsic partition coefficients, Kintp, Kintoc), and between colloids and soluble phase (Kcoc) showed that intrinsic partition coefficients (Kintp, Kintoc) are between 25% and 96%, and between 18% and 82% higher than relevant observed partition coefficients values, and are much less variable. Secondly, Kcoc values are 3-4 orders of magnitude greater than Kintoc values, indicating that aquatic colloids are substantially more powerful sorbents for accumulating pharmaceuticals than sediments. Furthermore, mass balance calculations of pharmaceutical concentrations demonstrate that between 23% and 70% of propranolol, 17-62% of sulfamethoxazole, 7-58% of carbamazepine, 19-84% of indomethacine, and 9-74% of diclofenac are present in the colloidal phase. The results provide direct evidence that sorption to colloids provides an important sink for the pharmaceuticals in the aquatic environment. Such strong pharmaceutical/colloid interactions may provide a long-term storage of pharmaceuticals, hence, increasing their persistence while reducing their bioavailability in the environment. Pharmaceutical compounds have been detected not only in the aqueous phase but also in suspended particles; it is important, therefore, to have a holistic approach in future environmental fate investigation of pharmaceuticals. For example, more research is needed to assess the storage and long-term record of pharmaceutical residues in aquatic sediments by which benthic organisms will be most affected. Aquatic colloids have been shown to account for the accumulation of major fractions of total pharmaceutical concentrations in the aquatic environment, demonstrating unequivocally the importance of aquatic colloids as a sink for such residues in the aquatic systems. As aquatic colloids are abundant, ubiquitous, and highly powerful sorbents, they are expected to influence the bioavailability and bioaccumulation of such

  14. Effects of management legacies on stream fish and aquatic benthic macroinvertebrate assemblages

    USGS Publications Warehouse

    Quist, Michael C.; Schultz, Randall D.

    2014-01-01

    Fish and benthic macroinvertebrate assemblages often provide insight on ecological conditions for guiding management actions. Unfortunately, land use and management legacies can constrain the structure of biotic communities such that they fail to reflect habitat quality. The purpose of this study was to describe patterns in fish and benthic macroinvertebrate assemblage structure, and evaluate relationships between biota and habitat characteristics in the Chariton River system of south-central Iowa, a system likely influenced by various potential management legacies (e.g., dams, chemical removal of fishes). We sampled fishes, benthic macroinvertebrates, and physical habitat from a total of 38 stream reaches in the Chariton River watershed during 2002–2005. Fish and benthic macroinvertebrate assemblages were dominated by generalist species tolerant of poor habitat quality; assemblages failed to show any apparent patterns with regard to stream size or longitudinal location within the watershed. Metrics used to summarize fish assemblages and populations [e.g., presence–absence, relative abundance, Index of Biotic Integrity for fish (IBIF)] were not related to habitat characteristics, except that catch rates of piscivores were positively related to the depth and the amount of large wood. In contrast, family richness of benthic macroinvertebrates, richness of Ephemeroptera, Trichoptera, and Plecoptera taxa, and IBI values for benthic macroinvertebrates (IBIBM) were positively correlated with the amount of overhanging vegetation and inversely related to the percentage of fine substrate. A long history of habitat alteration by row-crop agriculture and management legacies associated with reservoir construction has likely resulted in a fish assemblage dominated by tolerant species. Intolerant and sensitive fish species have not recolonized streams due to downstream movement barriers (i.e., dams). In contrast, aquatic insect assemblages reflected aquatic habitat

  15. Effects of Management Legacies on Stream Fish and Aquatic Benthic Macroinvertebrate Assemblages

    NASA Astrophysics Data System (ADS)

    Quist, Michael C.; Schultz, Randall D.

    2014-09-01

    Fish and benthic macroinvertebrate assemblages often provide insight on ecological conditions for guiding management actions. Unfortunately, land use and management legacies can constrain the structure of biotic communities such that they fail to reflect habitat quality. The purpose of this study was to describe patterns in fish and benthic macroinvertebrate assemblage structure, and evaluate relationships between biota and habitat characteristics in the Chariton River system of south-central Iowa, a system likely influenced by various potential management legacies (e.g., dams, chemical removal of fishes). We sampled fishes, benthic macroinvertebrates, and physical habitat from a total of 38 stream reaches in the Chariton River watershed during 2002-2005. Fish and benthic macroinvertebrate assemblages were dominated by generalist species tolerant of poor habitat quality; assemblages failed to show any apparent patterns with regard to stream size or longitudinal location within the watershed. Metrics used to summarize fish assemblages and populations [e.g., presence-absence, relative abundance, Index of Biotic Integrity for fish (IBIF)] were not related to habitat characteristics, except that catch rates of piscivores were positively related to the depth and the amount of large wood. In contrast, family richness of benthic macroinvertebrates, richness of Ephemeroptera, Trichoptera, and Plecoptera taxa, and IBI values for benthic macroinvertebrates (IBIBM) were positively correlated with the amount of overhanging vegetation and inversely related to the percentage of fine substrate. A long history of habitat alteration by row-crop agriculture and management legacies associated with reservoir construction has likely resulted in a fish assemblage dominated by tolerant species. Intolerant and sensitive fish species have not recolonized streams due to downstream movement barriers (i.e., dams). In contrast, aquatic insect assemblages reflected aquatic habitat, particularly

  16. Effects of management legacies on stream fish and aquatic benthic macroinvertebrate assemblages.

    PubMed

    Quist, Michael C; Schultz, Randall D

    2014-09-01

    Fish and benthic macroinvertebrate assemblages often provide insight on ecological conditions for guiding management actions. Unfortunately, land use and management legacies can constrain the structure of biotic communities such that they fail to reflect habitat quality. The purpose of this study was to describe patterns in fish and benthic macroinvertebrate assemblage structure, and evaluate relationships between biota and habitat characteristics in the Chariton River system of south-central Iowa, a system likely influenced by various potential management legacies (e.g., dams, chemical removal of fishes). We sampled fishes, benthic macroinvertebrates, and physical habitat from a total of 38 stream reaches in the Chariton River watershed during 2002-2005. Fish and benthic macroinvertebrate assemblages were dominated by generalist species tolerant of poor habitat quality; assemblages failed to show any apparent patterns with regard to stream size or longitudinal location within the watershed. Metrics used to summarize fish assemblages and populations [e.g., presence-absence, relative abundance, Index of Biotic Integrity for fish (IBIF)] were not related to habitat characteristics, except that catch rates of piscivores were positively related to the depth and the amount of large wood. In contrast, family richness of benthic macroinvertebrates, richness of Ephemeroptera, Trichoptera, and Plecoptera taxa, and IBI values for benthic macroinvertebrates (IBIBM) were positively correlated with the amount of overhanging vegetation and inversely related to the percentage of fine substrate. A long history of habitat alteration by row-crop agriculture and management legacies associated with reservoir construction has likely resulted in a fish assemblage dominated by tolerant species. Intolerant and sensitive fish species have not recolonized streams due to downstream movement barriers (i.e., dams). In contrast, aquatic insect assemblages reflected aquatic habitat, particularly

  17. Persistent organic pollutants and mercury in marine biota of the Canadian Arctic: an overview of spatial and temporal trends.

    PubMed

    Braune, B M; Outridge, P M; Fisk, A T; Muir, D C G; Helm, P A; Hobbs, K; Hoekstra, P F; Kuzyk, Z A; Kwan, M; Letcher, R J; Lockhart, W L; Norstrom, R J; Stern, G A; Stirling, I

    2005-12-01

    This review summarizes and synthesizes the significant amount of data which was generated on mercury (Hg) and persistent organic pollutants (POPs) in Canadian Arctic marine biota since the first Canadian Arctic Contaminants Assessment Report (CACAR) was published in 1997. This recent body of work has led to a better understanding of the current levels and spatial and temporal trends of contaminants in biota, including the marine food species that northern peoples traditionally consume. Compared to other circumpolar countries, concentrations of many organochlorines (OCs) in Canadian Arctic marine biota are generally lower than in the European Arctic and eastern Greenland but are higher than in Alaska, whereas Hg concentrations are substantially higher in Canada than elsewhere. Spatial coverage of OCs in ringed seals, beluga and seabirds remains a strength of the Arctic contaminant data set for Canada. Concentrations of OCs in marine mammals and seabirds remain fairly consistent across the Canadian Arctic although subtle differences from west to east and south to north are found in the proportions of various chemicals. The most significant development since 1997 is improvement in the temporal trend data sets, thanks to the use of archived tissue samples from the 1970s and 1980s, long-term studies using archeological material, as well as the continuation of sampling. These data cover a range of species and chemicals and also include retrospective studies on new chemicals such as polybrominated diphenyl ethers. There is solid evidence in a few species (beluga, polar bear, blue mussels) that Hg at some locations has significantly increased from pre-industrial times to the present; however, the temporal trends of Hg over the past 20-30 years are inconsistent. Some animal populations exhibited significant increases in Hg whereas others did not. Therefore, it is currently not possible to determine if anthropogenic Hg is generally increasing in Canadian Arctic biota. It is

  18. Compartmentalisation Strategies for Hydrocarbon-based Biota on Titan

    NASA Astrophysics Data System (ADS)

    Norman, L.; Fortes, A. D.; Skipper, N.; Crawford, I.

    2013-05-01

    The goal of our study is to determine the nature of compartimentalisation strategies for any organisms inhabiting the hydrocarbon lakes of Titan (the largest moon of Saturn). Since receiving huge amounts of data via the Cassini-Huygens mission to the Saturnian system astrobiologists have speculated that exotic biota might currently inhabit this environment. The biota have been theorized to consume acetylene and hydrogen whilst excreting methane (1,2) leading to an anomalous hydrogen depletion near the surface; and there has been evidence to suggest this depletion exists (3). Nevertheless, many questions still remain concerning the possible physiological traits of biota in these environments, including whether cell-like structures can form in low temperature, low molecular weight hydrocarbons. The backbone of terrestrial cell membranes are vesicular structures composed primarily of a phospholipid bilayer with the hydrophilic head groups arranged around the periphery and are thought to be akin to the first protocells that terrestrial life utilised (4). It my be possible that reverse vesicles composed of a bilayer with the hydrophilic head groups arranged internally and a nonpolar core may be ideal model cell membranes for hydrocarbon-based organisms inhabiting Titan's hydrocarbon lakes (5). A variety of different surfactants have been used to create reverse vesicles in nonpolar liquids to date including; non-ionic ethers (7) and esters (6, 8); catanionic surfactant mixtures (9); zwitterionic gemini surfactants (10); coblock polymer surfactants (11); and zwitterionic phospholipid surfactants (12). In order to discover whether certain phospholipids can exhibit vesicular behaviour within hydrocarbon liquids, and to analyse their structure, we have carried out experimental studies using environmental conditions that are increasing comparable to those found on the surface of Titan. Experimental methods that have been used to determine the presence of vesicles include the

  19. Occurrence and fate of barbiturates in the aquatic environment.

    PubMed

    Peschka, Manuela; Eubeler, Jan P; Knepper, Thomas P

    2006-12-01

    Barbiturates have been widely used as sedative hypnotics in the mid-1960s and since then mainly as veterinary drugs. To monitor their presence and fate in the aquatic environment, a method based on gas chromatography-mass spectrometry (GC-MS) has been developed to quantify butalbital, secobarbital, hexobarbital, aprobarbital, phenobarbital, and pentobarbital, all with a limit of detection (LOD) down to 1 ng/L. From the various investigated waste and surface water samples, barbiturates were only, but regularly detected in the Mulde, a tributary of the river Elbe in Germany at relevant concentrations up to several microg/L. Investigations of groundwater being affected with wastewater infiltration several decades ago also revealed a barbiturate pattern, indicating a strong recalcitrance of these drugs. To confirm this hypothesis, studies were carried out on biotic and abiotic degradation. Both, the biodegradability under aerobic conditions and hydrolysis did not show any degradation, implementing, that the investigated barbiturates, once released into the aquatic environment, show high stability over a long period of time.

  20. Environmental enrichment for aquatic animals.

    PubMed

    Corcoran, Mike

    2015-05-01

    Aquatic animals are the most popular pets in the United States based on the number of owned pets. They are popular display animals and are increasingly used in research settings. Enrichment of captive animals is an important element of zoo and laboratory medicine. The importance of enrichment for aquatic animals has been slower in implementation. For a long time, there was debate over whether or not fish were able to experience pain or form long-term memories. As that debate has reduced and the consciousness of more aquatic animals is accepted, the need to discuss enrichment for these animals has increased. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Aquatic Invertebrate Development Working Group

    NASA Technical Reports Server (NTRS)

    Meyers, D.

    1985-01-01

    Little definitive evidence exists to show that gravity plays a major role in embyrogenesis of aquatic invertebrates. Two reasons for this may be: (1) few studies have been done that emphasize the role of gravity; and (2) there simply may not be any gravity effect. The buoyant nature of the aquatic environment could have obscured any evolutionary effect of gravity. The small size of most eggs and their apparent lack of orientation suggests reduced gravitational influence. Therefore, it is recommended that the term development, as applied to aquatic invertebrates, be loosely defined to encompass behavioral and morphological parameters for which baseline data already exist.

  2. Summary of biological investigations relating to surface-water quality in the Kentucky River basin, Kentucky

    USGS Publications Warehouse

    Bradfield, A.D.; Porter, S.D.

    1990-01-01

    The Kentucky River basin, an area of approximately 7,000 sq mi, is divided into five hydrologic units that drain parts of three physiographic regions. Data on aquatic biological resources were collected and reviewed to assess conditions in the major streams for which data were available. The North, Middle, and South Forks of the Kentucky River are in the Eastern Coal Field physiographic region. Streams in this region are affected by drainage from coal mines and oil and gas operations, and many support only tolerant biotic stream forms. The Kentucky River from the confluence of the three forks to the Red River, is in the Knobs physiographic region. Oil and gas production operations and point discharges from municipalities have affected many streams in this region. The Red River, a Kentucky Wild River, supported a unique flora and fauna but accelerated sedimentation has eliminated many species of mussels. The Millers Creek drainage is affected by brines discharged from oil and gas operations, and some reaches support only halophilic algae and a few fish. The Kentucky River from the Red River to the Ohio River is in the Bluegrass physiographic region. Heavy sediment loads and sewage effluent from urban centers have limited the aquatic biota in this region. Silver Creek and South Elkhorn Creek have been particularly affected and aquatic communities in these streams are dominated by organisms tolerant of low dissolved oxygen concentrations. Biological data for other streams indicate that habitat and water quality conditions are favorable for most commonly occurring aquatic organisms. (USGS)

  3. [Allelopathy autotoxicity effects of aquatic extracts from rhizospheric soil on rooting and growth of stem cuttings in Pogostemon cablin].

    PubMed

    Tang, Kun; Li, Ming; Dong, Shan; Li, Yun-qi; Huang, Jie-wen; Li, Long-ming

    2014-06-01

    To study the allelopathy effects of aquatic extracts from rhizospheric soil on the rooting and growth of stem cutting in Pogostemon cablin, and to reveal its mechanism initially. The changes of rhizogenesis characteristics and physic-biochemical during cutting seedlings were observed when using different concentration of aquatic extracts from rhizospheric soil. Aquatic extracts from rhizospheric soil had significant inhibitory effects on rooting rate, root number, root length, root activity, growth rate of cutting with increasing concentrations of tissue extracts; The chlorophyll content of cutting seedlings were decreased, but content of MDA were increased, and activities of POD, PPO and IAAO in cutting seedlings were affected. Aquatic extracts from rhizospheric soil of Pogostemon cablin have varying degrees of inhibitory effects on the normal rooting and growth of stem cuttings.

  4. Aquatic habitats of Canaan Valley, West Virginia: Diversity and environmental threats

    USGS Publications Warehouse

    Snyder, C.D.; Young, J.A.; Stout, B. M.

    2006-01-01

    We conducted surveys of aquatic habitats during the spring and summer of 1995 in Canaan Valley, WV, to describe the diversity of aquatic habitats in the valley and identify issues that may threaten the viability of aquatic species. We assessed physical habitat and water chemistry of 126 ponds and 82 stream sites, and related habitat characteristics to landscape variables such as geology and terrain. Based on our analyses, we found two issues likely to affect the viability of aquatic populations in the valley. The first issue was acid rain and the extent to which it potentially limits the distribution of aquatic and semi-aquatic species, particularly in headwater portions of the watershed. We estimate that nearly 46%, or 56 kilometers of stream, had pH levels that would not support survival and reproduction of Salvelinuw fontinalis (brook trout), one of the most acid-tolerant fishes in the eastern US. The second issue was the influence of Castor canadensis (beaver) activity. In the Canaan Valley State Park portion of the valley, beaver have transformed 4.7 kilometers of stream (approximately 17% of the total) to pond habitat through their dam building. This has resulted in an increase in pond habitat, a decrease in stream habitat, and a fragmented stream network (i.e., beaver ponds dispersed among stream reaches). In addition, beaver have eliminated an undetermined amount of forested riparian area through their foraging activities. Depending on the perspective, beaver-mediated changes can be viewed as positive or negative. Increases in pond habitat may increase habitat heterogeneity with consequent increases in biological diversity. In contrast, flooding associated with beaver activity may eliminate lowland wetlands and associated species, create barriers to fish dispersal, and possibly contribute to low dissolved oxygen levels in the Blackwater River. We recommend that future management strategies for the wildlife refuge be viewed in the context of these two issues

  5. INTERACTIONS OF LIGHT AND CHEMICAL REACTIONS IN THE AQUATIC ENVIRONMENT: KINETIC AND MECHANISTIC ASPECTS

    EPA Science Inventory

    Changes in the ozone layer over the past two decades have resulted in increases in solar ultraviolet (UV) radiation that reaches the surface of aquatic environments. Recent studies have demonstrated that these UV increases cause changes in photochemical reactions that affect the...

  6. ENANTIOMERIC OCCURRENCE AND DISTRIBUTION OF CHIRAL ORGANOCHLORINE COMPOUNDS IN U.S. RIVER SEDIMENT AND BIOTA

    EPA Science Inventory

    River sediment and biota (fish, bivalves) from throughout the continental U.S. were analyzed for chiral organochlorine compounds (o,p'-DDT and DDD, some chlordane compounds, PCB atropisomers) to assess spatial trends in environmental chirality. Chiral PCB enantiomers were racemic...

  7. Crop rotations and poultry litter impact dynamic soil chemical properties and soil biota long-term

    USDA-ARS?s Scientific Manuscript database

    Dynamic soil physiochemical interactions with conservation agricultural practices and soil biota are largely unknown. Therefore, this study aims to quantify long-term (12-yr) impacts of cover crops, poultry litter, crop rotations, and conservation tillage and their interactions on soil physiochemica...

  8. The assembly of montane biotas: linking Andean tectonics and climatic oscillations to independent regimes of diversification in Pionus parrots

    PubMed Central

    Ribas, Camila C; Moyle, Robert G; Miyaki, Cristina Y; Cracraft, Joel

    2007-01-01

    The mechanisms underlying the taxonomic assembly of montane biotas are still poorly understood. Most hypotheses have assumed that the diversification of montane biotas is loosely coupled to Earth history and have emphasized instead the importance of multiple long-distance dispersal events and biotic interactions, particularly competition, for structuring the taxonomic composition and distribution of montane biotic elements. Here we use phylogenetic and biogeographic analyses of species in the parrot genus Pionus to demonstrate that standing diversity within montane lineages is directly attributable to events of Earth history. Phylogenetic relationships confirm three independent biogeographic disjunctions between montane lineages, on one hand, and lowland dry-forest/wet-forest lineages on the other. Temporal estimates of lineage diversification are consistent with the interpretation that the three lineages were transported passively to high elevations by mountain building, and that subsequent diversification within the Andes was driven primarily by Pleistocene climatic oscillations and their large-scale effects on habitat change. These results support a mechanistic link between diversification and Earth history and have general implications for explaining high altitudinal disjuncts and the origin of montane biotas. PMID:17686731

  9. Polychlorinated biphenyls in aquatic invertebrates and fish and observations about nitrogen and carbon isotope composition in relation to trophic structure and bioaccumulation patterns, Lake Worth and Meandering Road Creek, Fort Worth, Texas, 2007-08

    USGS Publications Warehouse

    Moring, J. Bruce

    2010-01-01

    with all other aquatic invertebrate and fish. The relative depletion of 13C might indicate the carbon sources consumed by true midge larvae are different from the carbon sources consumed by all other taxon that were sampled. Ratios of stable nitrogen isotopes nitrogen-15 to nitrogen-14 (delta15N) were similar between taxa from the Lake Worth site and Woods Inlet sites. The sum of 15 PCB-congener concentrations, however, was an order of magnitude higher in largemouth bass from the upper Woods Inlet site, indicating that PCB-congener concentrations in lake bed sediment likely controls biomagnification within the lake because of the similarities in trophic structure of the resident aquatic community. The biota at the Lake Worth reference site, where PCBs were not detected in the surficial sediment during previous studies, were less contaminated than the biota at sites where PCBs had been detected in the surficial sediment. The highest trophic-level consumers (as evidenced by the most 15N-enriched delta15N values) showed the maximum bioaccumulation.

  10. Hydrologic disturbance and response of aquatic biota in Big Darby Creek basin, Ohio

    USGS Publications Warehouse

    Hambrook, J.A.; Koltun, G.F.; Palcsak, B.B.; Tertuliani, J.S.

    1997-01-01

    Washout and recolonization of macroinvertebrates and algae associated with a spring and summer storm were measured at three sites in Ohio's Big Darby Creek Basin. Related factors, such as streamflow magnitude, shear stress, and streamed disturbance were considered when interpreting observed changes in densities and community structure of macroinvertebrates and algae. During the study, 184 macroinvertebrate taxa and 202 algal taxa were identified. The major taxonomic groups for macroinvertebrates were midges and other true flies (Diptera), caddisflies (Trichoptera), beetles (Coleoptera), mayflies (Ephemeroptera), and stoneflies (Plecoptera). Diatoms were the dominant algae (in terms of percentage of total taxa found) followed by green algae, blue-green algae, euglenoids, golden flagellates, and freshwater red algae. Streamflows associated with the storm events that occurred during April 6-16 and June 23-July 5, 1994, probably had little effect on streambed elevations, but streambed disturbance was documented in the form of shifts in the median particle-size diameters of the subsurface bed materials. The streamflow magnitudes did not correlate well with the magnitude of observed changes in macroinvertebrate and algal-cell densities, but reductions in macroinvertebrate and algal-cell densities generally did occur. Local minima of macroinvertebrate density did not generally correspond to the first sample after the storms, but instead lagged by about 1 to 3 weeks. Other biotic factors, such as emergence of Diptera, probably affected the observed mid-July depression in macroinvertebrate densities. Evaluation of pre-event macroinvertebrate community structure in terms of functional feeding groups and flow-exposure groups showed that, on the basis of percentage of total taxa found, gatherers were the dominant feeding group and flow-facultative taxa were the dominant flow-exposure group. Densities of gatherers decreased from pre-event levels following all the storm events

  11. Novel aquatic modules for bioregenerative life-support systems based on the closed equilibrated biological aquatic system (c.e.b.a.s.)

    NASA Astrophysics Data System (ADS)

    Bluem, Volker; Paris, Frank

    2002-06-01

    The closed equilibrated biological aquatic system (C.E.B.A.S) is a man-made aquatic ecosystem which consists of four subcomponents: an aquatic animal habitat, an aquatic plant bioreactor, an ammonia oxidizing bacteria filter and a data acquisition/control unit. It is a precursor for different types of fish and aquatic plant production sites which are disposed for the integration into bioregenerative life-support systems. The results of two successful spaceflights of a miniaturized C.E.B.A.S version (the C.E.B.A.S. MINI MODULE) allow the optimization of aquatic food production systems which are already developed in the ground laboratory and open new aspects for their utilization as aquatic modules in space bioregenerative life support systems. The total disposition offers different stages of complexity of such aquatic modules starting with simple but efficient aquatic plant cultivators which can be implemented into water recycling systems and ending up in combined plant/fish aquaculture in connection with reproduction modules and hydroponics applications for higher land plants. In principle, aquaculture of fishes and/or other aquatic animals edible for humans offers optimal animal protein production under lowered gravity conditions without the tremendous waste management problems connected with tetrapod breeding and maintenance. The paper presents details of conducted experimental work and of future dispositions which demonstrate clearly that aquaculture is an additional possibility to combine efficient and simple food production in space with water recycling utilizing safe and performable biotechnologies. Moreover, it explains how these systems may contribute to more variable diets to fulfill the needs of multicultural crews.

  12. Aquatic-macroinvertebrate communities of Prairie-Pothole wetlands and lakes under a changed climate

    USGS Publications Warehouse

    McLean, Kyle I.; Mushet, David M.; Renton, David A.; Stockwell, Craig A.

    2016-01-01

    Understanding how aquatic-macroinvertebrate communities respond to changes in climate is important for biodiversity conservation in the Prairie Pothole Region and other wetland-rich landscapes. We sampled macroinvertebrate communities of 162 wetlands and lakes previously sampled from 1966 to 1976, a much drier period compared to our 2012–2013 sampling timeframe. To identify possible influences of a changed climate and predation pressures on macroinvertebrates, we compared two predictors of aquatic-macroinvertebrate communities: ponded-water dissolved-ion concentration and vertebrate-predator presence/abundance. Further, we make inferences of how macroinvertebrate communities were structured during the drier period when the range of dissolved-ion concentrations was much greater and fish occurrence in aquatic habitats was rare. We found that aquatic-macroinvertebrate community structure was influenced by dissolved-ion concentrations through a complex combination of direct and indirect relationships. Ion concentrations also influenced predator occurrence and abundance, which indirectly affected macroinvertebrate communities. It is important to consider both abiotic and biotic gradients when predicting how invertebrate communities will respond to climate change. Generally, in the wetlands and lakes we studied, freshening of ponded water resulted in more homogenous communities than occurred during a much drier period when salinity range among sites was greater.

  13. What Is Your Aquatics Liability IQ?

    ERIC Educational Resources Information Center

    Johnson, Ralph L.

    1984-01-01

    The author presents three court case studies and questions related to the cases, so that aquatic facility owners can test their liability perception. Recommendations are made in seven areas as defenses against aquatic liability. (JMK)

  14. Review of the ecotoxicological effects of emerging contaminants to soil biota.

    PubMed

    Gomes, Ana R; Justino, Celine; Rocha-Santos, Teresa; Freitas, Ana C; Duarte, Armando C; Pereira, Ruth

    2017-08-24

    In recent years, emerging contaminants (e.g. pesticides and their metabolites, pharmaceuticals, personal and house care products, life-style compounds, food additives, industrial products and wastes, as well as nanomaterials) have become a problem to the environment. In fact, the cumulative use of a panoply of chemical substances in agriculture, industrial activities, in our homes and in health care services has led to their recent appearance in detectable levels in soils, surface, and groundwater resources, with unpredictable consequences for these ecosystems. Few data exist regarding the toxicity and potential for bioaccumulation in biota. When available, data were obtained only for some representatives of the main groups of chemical substances, and for a limited number of species, following non-standard protocols. This makes difficult the calculation of predicted no effect concentrations (PNEC) and the existence of sufficient data to set limits for their release into the environment. This is particularly concerning for the soil compartment, since only recently the scientific community, regulators, and the public have realised the importance of protecting this natural resource and its services to guarantee the sustainability of terrestrial ecosystems and human well-being. In this context, this review paper aims to identify the major groups of soil emerging contaminants, their sources, pathways and receptors, and in parallel to analyse existing ecotoxicological data for soil biota.

  15. Distribution of Microplastics and Nanoplastics in Aquatic Ecosystems and Their Impacts on Aquatic Organisms, with Emphasis on Microalgae.

    PubMed

    Wan, Jun-Kit; Chu, Wan-Loy; Kok, Yih-Yih; Lee, Choy-Sin

    2018-06-06

    Plastics, with their many useful physical and chemical properties, are widely used in various industries and activities of daily living. Yet, the insidious effects of plastics, particularly long-term effects on aquatic organisms, are not properly understood. Plastics have been shown to degrade to micro- and nanosize particles known as microplastics and nanoplastics, respectively. These minute particles have been shown to cause various adverse effects on aquatic organisms, ranging from growth inhibition, developmental delay and altered feeding behaviour in aquatic animals to decrease of photosynthetic efficiency and induction of oxidative stress in microalgae. This review paper covers the distribution of microplastics and nanoplastics in aquatic ecosystems, focusing on their effects on microalgae as well as co-toxicity of microplastics and nanoplastics with other pollutants. Besides that, this review paper also discusses future research directions which could be taken to gain a better understanding of the impacts of microplastics and nanoplastics on aquatic ecosystems.

  16. Meta-Analysis of the Copper, Zinc, and Cadmium Absorption Capacities of Aquatic Plants in Heavy Metal-Polluted Water

    PubMed Central

    Li, Jing; Yu, Haixin; Luan, Yaning

    2015-01-01

    The use of aquatic plants for phytoremediation is an important method for restoring polluted ecosystems. We sought to analyze the capacity of different aquatic plant species to absorb heavy metals and to summarize available relevant scientific data on this topic. We present a meta-analysis of Cu, Zn, and Cd absorption capacities of aquatic plants to provide a scientific basis for the selection of aquatic plants suitable for remediation of heavy-metal pollution. Plants from the Gramineae, Pontederiaceae, Ceratophyllaceae, Typhaceae and Haloragaceae showed relatively strong abilities to absorb these metals. The ability of a particular plant species to absorb a given metal was strongly correlated with its ability to absorb the other metals. However, the absorption abilities varied with the plant organ, with the following trend: roots > stems > leaves. The pH of the water and the life habits of aquatic plants (submerged and emerged) also affect the plant’s ability to absorb elements. Acidic water aids the uptake of heavy metals by plants. The correlation observed between element concentrations in plants with different aquatic life habits suggested that the enrichment mechanism is related to the surface area of the plant exposed to water. We argue that this meta-analysis would aid the selection of aquatic plants suitable for heavy-metal absorption from polluted waters. PMID:26703632

  17. Harvest-induced evolution: insights from aquatic and terrestrial systems

    PubMed Central

    Festa-Bianchet, Marco

    2017-01-01

    Commercial and recreational harvests create selection pressures for fitness-related phenotypic traits that are partly under genetic control. Consequently, harvesting can drive evolution in targeted traits. However, the quantification of harvest-induced evolutionary life history and phenotypic changes is challenging, because both density-dependent feedback and environmental changes may also affect these changes through phenotypic plasticity. Here, we synthesize current knowledge and uncertainties on six key points: (i) whether or not harvest-induced evolution is happening, (ii) whether or not it is beneficial, (iii) how it shapes biological systems, (iv) how it could be avoided, (v) its importance relative to other drivers of phenotypic changes, and (vi) whether or not it should be explicitly accounted for in management. We do this by reviewing findings from aquatic systems exposed to fishing and terrestrial systems targeted by hunting. Evidence from aquatic systems emphasizes evolutionary effects on age and size at maturity, while in terrestrial systems changes are seen in weapon size and date of parturition. We suggest that while harvest-induced evolution is likely to occur and negatively affect populations, the rate of evolutionary changes and their ecological implications can be managed efficiently by simply reducing harvest intensity. This article is part of the themed issue ‘Human influences on evolution, and the ecological and societal consequences'. PMID:27920381

  18. INTERACTIONS OF INTRODUCED BACTERIA AND AQUATIC INVERTEBRATES

    EPA Science Inventory

    Bacteria enter into stream environments from a variety of sources and interact in varying ways with other biota. There were three basic objectives for this project: 1) to examine the effect of different types of macroinvertebrates on bacterial survival and distribution, 2) to com...

  19. Obesogens in the aquatic environment: an evolutionary and toxicological perspective.

    PubMed

    Capitão, Ana; Lyssimachou, Angeliki; Castro, Luís Filipe Costa; Santos, Miguel M

    2017-09-01

    The rise of obesity in humans is a major health concern of our times, affecting an increasing proportion of the population worldwide. It is now evident that this phenomenon is not only associated with the lack of exercise and a balanced diet, but also due to environmental factors, such as exposure to environmental chemicals that interfere with lipid homeostasis. These chemicals, also known as obesogens, are present in a wide range of products of our daily life, such as cosmetics, paints, plastics, food cans and pesticide-treated food, among others. A growing body of evidences indicates that their action is not limited to mammals. Obesogens also end up in the aquatic environment, potentially affecting its ecosystems. In fact, reports show that some environmental chemicals are able to alter lipid homeostasis, impacting weight, lipid profile, signaling pathways and/or protein activity, of several taxa of aquatic animals. Such perturbations may give rise to physiological disorders and disease. Although largely unexplored from a comparative perspective, the key molecular components implicated in lipid homeostasis have likely appeared early in animal evolution. Therefore, it is not surprising that the obesogen effects are found in other animal groups beyond mammals. Collectively, data indicates that suspected obesogens impact lipid metabolism across phyla that have diverged over 600 million years ago. Thus, a consistent link between environmental chemical exposure and the obesity epidemic has emerged. This review aims to summarize the available information on the effects of putative obesogens in aquatic organisms, considering the similarities and differences of lipid homeostasis pathways among metazoans, thus contributing to a better understanding of the etiology of obesity in human populations. Finally, we identify the knowledge gaps in this field and we set future research priorities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Aquatic arsenic: phytoremediation using floating macrophytes.

    PubMed

    Rahman, M Azizur; Hasegawa, H

    2011-04-01

    Phytoremediation, a plant based green technology, has received increasing attention after the discovery of hyperaccumulating plants which are able to accumulate, translocate, and concentrate high amount of certain toxic elements in their above-ground/harvestable parts. Phytoremediation includes several processes namely, phytoextraction, phytodegradation, rhizofiltration, phytostabilization and phytovolatilization. Both terrestrial and aquatic plants have been tested to remediate contaminated soils and waters, respectively. A number of aquatic plant species have been investigated for the remediation of toxic contaminants such as As, Zn, Cd, Cu, Pb, Cr, Hg, etc. Arsenic, one of the deadly toxic elements, is widely distributed in the aquatic systems as a result of mineral dissolution from volcanic or sedimentary rocks as well as from the dilution of geothermal waters. In addition, the agricultural and industrial effluent discharges are also considered for arsenic contamination in natural waters. Some aquatic plants have been reported to accumulate high level of arsenic from contaminated water. Water hyacinth (Eichhornia crassipes), duckweeds (Lemna gibba, Lemna minor, Spirodela polyrhiza), water spinach (Ipomoea aquatica), water ferns (Azolla caroliniana, Azolla filiculoides, and Azolla pinnata), water cabbage (Pistia stratiotes), hydrilla (Hydrilla verticillata) and watercress (Lepidium sativum) have been studied to investigate their arsenic uptake ability and mechanisms, and to evaluate their potential in phytoremediation technology. It has been suggested that the aquatic macrophytes would be potential for arsenic phytoremediation, and this paper reviews up to date knowledge on arsenic phytoremediation by common aquatic macrophytes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. State of the Science White Paper: Effects of Plastics Pollution on Aquatic Life and Aquatic-Dependent Wildlife

    EPA Pesticide Factsheets

    This document is a state-of-the-science review – one that summarizes available scientific information on the effects of chemicals associated with plastic pollution and their potential impacts on aquatic life and aquatic-dependent wildlife.

  2. Ants impact the composition of the aquatic macroinvertebrate communities of a myrmecophytic tank bromeliad.

    PubMed

    Dejean, Alain; Compin, Arthur; Leponce, Maurice; Azémar, Frédéric; Bonhomme, Camille; Talaga, Stanislas; Pelozuelo, Laurent; Hénaut, Yann; Corbara, Bruno

    2018-03-01

    In an inundated Mexican forest, 89 out of 92 myrmecophytic tank bromeliads (Aechmea bracteata) housed an associated ant colony: 13 sheltered Azteca serica, 43 Dolichoderus bispinosus, and 33 Neoponera villosa. Ant presence has a positive impact on the diversity of the aquatic macroinvertebrate communities (n=30 bromeliads studied). A Principal Component Analysis (PCA) showed that the presence and the species of ant are not correlated to bromeliad size, quantity of water, number of wells, filtered organic matter or incident radiation. The PCA and a generalized linear model showed that the presence of Azteca serica differed from the presence of the other two ant species or no ants in its effects on the aquatic invertebrate community (more predators). Therefore, both ant presence and species of ant affect the composition of the aquatic macroinvertebrate communities in the tanks of A. bracteata, likely due to ant deposition of feces and other waste in these tanks. Copyright © 2018. Published by Elsevier Masson SAS.

  3. 40 CFR 230.76 - Actions affecting human use.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Actions affecting human use. 230.76... Minimize Adverse Effects § 230.76 Actions affecting human use. Minimization of adverse effects on human use... aquatic areas; (c) Timing the discharge to avoid the seasons or periods when human recreational activity...

  4. 40 CFR 230.76 - Actions affecting human use.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Actions affecting human use. 230.76... Minimize Adverse Effects § 230.76 Actions affecting human use. Minimization of adverse effects on human use... aquatic areas; (c) Timing the discharge to avoid the seasons or periods when human recreational activity...

  5. 40 CFR 230.76 - Actions affecting human use.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Actions affecting human use. 230.76... Minimize Adverse Effects § 230.76 Actions affecting human use. Minimization of adverse effects on human use... aquatic areas; (c) Timing the discharge to avoid the seasons or periods when human recreational activity...

  6. 40 CFR 230.76 - Actions affecting human use.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Actions affecting human use. 230.76... Minimize Adverse Effects § 230.76 Actions affecting human use. Minimization of adverse effects on human use... aquatic areas; (c) Timing the discharge to avoid the seasons or periods when human recreational activity...

  7. 40 CFR 230.76 - Actions affecting human use.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Actions affecting human use. 230.76... Minimize Adverse Effects § 230.76 Actions affecting human use. Minimization of adverse effects on human use... aquatic areas; (c) Timing the discharge to avoid the seasons or periods when human recreational activity...

  8. Project WILD Aquatic K-12 Curriculum and Activity Guide

    ERIC Educational Resources Information Center

    Council for Environmental Education, 2011

    2011-01-01

    The "Project WILD Aquatic K-12 Curriculum and Activity Guide" emphasizes aquatic wildlife and aquatic ecosystems. It is organized in topic units and is based on the Project WILD conceptual framework. Because these activities are designed for integration into existing courses of study, instructors may use one or many Project WILD Aquatic activities…

  9. Toxicological effects of pyrethroids on non-target aquatic insects.

    PubMed

    Antwi, Frank B; Reddy, Gadi V P

    2015-11-01

    The toxicological effects of pyrethroids on non-target aquatic insects are mediated by several modes of entry of pyrethroids into aquatic ecosystems, as well as the toxicological characteristics of particular pyrethroids under field conditions. Toxicokinetics, movement across the integument of aquatic insects, and the toxicodynamics of pyrethroids are discussed, and their physiological, symptomatic and ecological effects evaluated. The relationship between pyrethroid toxicity and insecticide uptake is not fully defined. Based on laboratory and field data, it is likely that the susceptibility of aquatic insects (vector and non-vector) is related to biochemical and physiological constraints associated with life in aquatic ecosystems. Understanding factors that influence aquatic insects susceptibility to pyrethroids is critical for the effective and safe use of these compounds in areas adjacent to aquatic environments. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Quantifying aquatic insect deposition from lake to land.

    PubMed

    Dreyer, Jamin; Townsend, Philip A; Hook, James C; Hoekman, David; Vander Zanden, M Jake; Gratton, Claudio

    2015-02-01

    Adjacent ecosystems are influenced by organisms that move across boundaries, such as insects with aquatic larval stages and terrestrial adult stages, which transport energy and nutrients from water to land. However, the ecosystem-level effect of aquatic insects on land has generally been ignored, perhaps because the organisms themselves are individually small. At the naturally productive Lake Mývatn, Iceland, we used two readily measured quantities: total insect emergence from water and relative insect density on land, to demonstrate an approach for estimating aquatic insect deposition (e.g., kg N x m(-2) x yr(-1)) to shore. Estimates from emergence traps between 2008 and 20.11 indicated a range of 0.15-3.7 g x m(-2) x yr(-1), or a whole-lake emergence of 3.1-76 Mg/yr; all masses are given as dry mass. Using aerial infall trap measurements of midge relative abundance over land, we developed a local-maximum decay function model to predict proportional midge deposition with distance from the lake. The dispersal model predicted midge abundance with R2 = 0.89, a pattern consistent among years, with peak midge deposition occurring 20-25 m inland and 70% of midges deposited within 100 m of shore. During a high-midge year (2008), we estimate midge deposition within the first 50 m of shoreline to be 100 kg xha(-1) x yr(-1), corresponding to inputs of 10 kg N x ha(-1) x yr(-1) and 1 kg P x ha(-1) x yr(-1), or about three to five times above background terrestrial N deposition rates. Consistent with elevated N input where midges are most dense, we observed that soil available nitrate in resin bags decreases with increasing distance from the lake. Our approach, generalizable to other systems, shows that aquatic insects can be a major source of nutrients to terrestrial ecosystems and have the capacity to significantly affect ecosystem processes.

  11. Methane emissions to the atmosphere through aquatic plants

    NASA Technical Reports Server (NTRS)

    Sebacher, D. I.; Harriss, R. C.; Bartlett, K. B.

    1985-01-01

    The movement of methane (CH4) from anaerobic sediments through the leaves, stems, and flowers of aquatic plants and into the atmosphere was found to provide a significant pathway for the emission of CH4 from the aquatic substrates of flooded wetlands. Methane concentrations well above the surrounding ambient air levels were found in the mesophyll of 16 varies of aquatic plants and are attributed to transpiration, diffusion, and pressure-induced flow of gaseous CH4 from the roots when they are embedded in CH4-saturated anaerobic sediments. Methane emissions from the emergent parts of aquatic plants were measured using floating chamber techniques and by enclosing the plants in polyethylene bags of known volume. Concentration changes were monitored in the trapped air using syringes and gas chromatographic techniques. Vertical profiles of dissolved CH4 in sediment pore water surrounding the aquatic plants' rhizomes were obtained using an interstitial sampling technique. Methane emissions from the aquatic plants studied varied from 14.8 mg CH4/d to levels too low to be detectable. Rooted and unrooted freshwater aquatic plants were studied as well as saltwater and brackish water plants. Included in the experiment is detailed set of measurements on CH4 emissions from the common cattail (Typha latifolia). This paper illustrates that aquatic plants play an important gas exchange role in the C cycle between wetlands and the atmosphere.

  12. The role of aquatic fungi in transformations of organic matter mediated by nutrients

    Treesearch

    Cynthia J. Tant; Amy D. Rosemond; Andrew S. Mehring; Kevin A. Kuehn; John M. Davis

    2015-01-01

    1. We assessed the key role of aquatic fungi in modifying coarse particulate organic matter (CPOM) by affecting its breakdown rate, nutrient concentration and conversion to fine particulate organic matter (FPOM). Overall, we hypothesised that fungal-mediated conditioning and breakdown of CPOM would be accelerated when nutrient concentrations are increased and tested...

  13. CAM Photosynthesis in Submerged Aquatic Plants

    USGS Publications Warehouse

    Keeley, J.E.

    1998-01-01

    Crassulacean acid metabolism (CAM) is a CO2-concentrating mechanism selected in response to aridity in terrestrial habitats, and, in aquatic environments, to ambient limitations of carbon. Evidence is reviewed for its presence in five genera of aquatic vascular plants, including Isoe??tes, Sagittaria, Vallisneria, Crassula, and Littorella. Initially, aquatic CAM was considered by some to be an oxymoron, but some aquatic species have been studied in sufficient detail to say definitively that they possess CAM photosynthesis. CO2-concentrating mechanisms in photosynthetic organs require a barrier to leakage; e.g., terrestrial C4 plants have suberized bundle sheath cells and terrestrial CAM plants high stomatal resistance. In aquatic CAM plants the primary barrier to CO2 leakage is the extremely high diffusional resistance of water. This, coupled with the sink provided by extensive intercellular gas space, generates daytime CO2(Pi) comparable to terrestrial CAM plants. CAM contributes to the carbon budget by both net carbon gain and carbon recycling, and the magnitude of each is environmentally influenced. Aquatic CAM plants inhabit sites where photosynthesis is potentially limited by carbon. Many occupy moderately fertile shallow temporary pools that experience extreme diel fluctuations in carbon availability. CAM plants are able to take advantage of elevated nighttime CO2 levels in these habitats. This gives them a competitive advantage over non-CAM species that are carbon starved during the day and an advantage over species that expend energy in membrane transport of bicarbonate. Some aquatic CAM plants are distributed in highly infertile lakes, where extreme carbon limitation and light are important selective factors. Compilation of reports on diel changes in titratable acidity and malate show 69 out of 180 species have significant overnight accumulation, although evidence is presented discounting CAM in some. It is concluded that similar proportions of the aquatic

  14. On the Origin of Pantepui montane biotas: A Perspective Based on the Phylogeny of Aulacorhynchus toucanets

    PubMed Central

    Bonaccorso, Elisa; Guayasamin, Juan M.

    2013-01-01

    To understand the origin of Pantepui montane biotas, we studied the biogeography of toucanets in the genus Aulacorhynchus. These birds are ideal for analyzing historical relationships among Neotropical montane regions, given their geographic distribution from Mexico south to Bolivia, including northern Venezuela (Cordillera de la Costa), and the Pantepui. Analyses were based on molecular phylogenies using mitochondrial and nuclear DNA sequences. Topology tests were applied to compare alternative hypotheses that may explain the current distribution of Aulacorhynchus toucanets, in the context of previous hypotheses of the origin of Pantepui montane biotas. Biogeographic reconstructions in RASP and Lagrange were used to estimate the ancestral area of the genus, and an analysis in BEAST was used to estimate a time framework for its diversification. A sister relationship between the Pantepui and Andes+Cordillera de la Costa was significantly more likely than topologies indicating other hypothesis for the origin of Pantepui populations. The Andes was inferred as the ancestral area for Aulacorhynchus, and the group has diversified since the late Miocene. The biogeographic patterns found herein, in which the Andes are the source for biotas of other regions, are consistent with those found for flowerpiercers and tanagers, and do not support the hypothesis of the geologically old Pantepui as a source of Neotropical montain diversity. Based on the high potential for cryptic speciation and isolation of Pantepui populations, we consider that phylogenetic studies of additional taxa are important from a conservation perspective. PMID:23840663

  15. On the Origin of Pantepui montane biotas: A Perspective Based on the Phylogeny of Aulacorhynchus toucanets.

    PubMed

    Bonaccorso, Elisa; Guayasamin, Juan M

    2013-01-01

    To understand the origin of Pantepui montane biotas, we studied the biogeography of toucanets in the genus Aulacorhynchus. These birds are ideal for analyzing historical relationships among Neotropical montane regions, given their geographic distribution from Mexico south to Bolivia, including northern Venezuela (Cordillera de la Costa), and the Pantepui. Analyses were based on molecular phylogenies using mitochondrial and nuclear DNA sequences. Topology tests were applied to compare alternative hypotheses that may explain the current distribution of Aulacorhynchus toucanets, in the context of previous hypotheses of the origin of Pantepui montane biotas. Biogeographic reconstructions in RASP and Lagrange were used to estimate the ancestral area of the genus, and an analysis in BEAST was used to estimate a time framework for its diversification. A sister relationship between the Pantepui and Andes+Cordillera de la Costa was significantly more likely than topologies indicating other hypothesis for the origin of Pantepui populations. The Andes was inferred as the ancestral area for Aulacorhynchus, and the group has diversified since the late Miocene. The biogeographic patterns found herein, in which the Andes are the source for biotas of other regions, are consistent with those found for flowerpiercers and tanagers, and do not support the hypothesis of the geologically old Pantepui as a source of Neotropical montain diversity. Based on the high potential for cryptic speciation and isolation of Pantepui populations, we consider that phylogenetic studies of additional taxa are important from a conservation perspective.

  16. Benthic invertebrates of benchmark streams in agricultural areas of eastern Wisconsin, Western Lake Michigan Drainages

    USGS Publications Warehouse

    Rheaume, S.J.; Lenz, B.N.; Scudder, B.C.

    1996-01-01

    Information gathered from these benchmark streams can be used as a regional reference for comparison with other streams in agricultural areas, based on communities of aquatic biota, habitat, and water quality.

  17. Global warming and environmental contaminants in aquatic organisms: the need of the etho-toxicology approach.

    PubMed

    Manciocco, Arianna; Calamandrei, Gemma; Alleva, Enrico

    2014-04-01

    Environmental contaminants are associated with a wide spectrum of pathological effects. Temperature increase affects ambient distribution and toxicity of these chemicals in the water environment, representing a potentially emerging problem for aquatic species with short-, medium- and long-term repercussions on human health through the food chain. We assessed peer-reviewed literature, including primary studies, review articles and organizational reports available. We focused on studies concerning toxicity of environmental pollutants within a global warming scenario. Existing knowledge on the effects that the increase of water temperature in a contaminated situation has on physiological mechanisms of aquatic organisms is presented. Altogether we consider the potential consequences for the human beings due to fish and shellfish consumption. Finally, we propose an etho-toxicological approach to study the effects of toxicants in conditions of thermal increase, using aquatic organisms as experimental models under laboratory controlled conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Procedure to select test organisms for environmental risk assessment of genetically modified crops in aquatic systems.

    PubMed

    Hilbeck, Angelika; Bundschuh, Rebecca; Bundschuh, Mirco; Hofmann, Frieder; Oehen, Bernadette; Otto, Mathias; Schulz, Ralf; Trtikova, Miluse

    2017-11-01

    For a long time, the environmental risk assessment (ERA) of genetically modified (GM) crops focused mainly on terrestrial ecosystems. This changed when it was scientifically established that aquatic ecosystems are exposed to GM crop residues that may negatively affect aquatic species. To assist the risk assessment process, we present a tool to identify ecologically relevant species usable in tiered testing prior to authorization or for biological monitoring in the field. The tool is derived from a selection procedure for terrestrial ecosystems with substantial but necessary changes to adequately consider the differences in the type of ecosystems. By using available information from the Water Framework Directive (2000/60/EC), the procedure can draw upon existing biological data on aquatic systems. The proposed procedure for aquatic ecosystems was tested for the first time during an expert workshop in 2013, using the cultivation of Bacillus thuringiensis (Bt) maize as the GM crop and 1 stream type as the receiving environment in the model system. During this workshop, species executing important ecological functions in aquatic environments were identified in a stepwise procedure according to predefined ecological criteria. By doing so, we demonstrated that the procedure is practicable with regard to its goal: From the initial long list of 141 potentially exposed aquatic species, 7 species and 1 genus were identified as the most suitable candidates for nontarget testing programs. Integr Environ Assess Manag 2017;13:974-979. © 2017 SETAC. © 2017 SETAC.

  19. PBT assessment under REACH: Screening for low aquatic bioaccumulation with QSAR classifications based on physicochemical properties to replace BCF in vivo testing on fish.

    PubMed

    Nendza, Monika; Kühne, Ralph; Lombardo, Anna; Strempel, Sebastian; Schüürmann, Gerrit

    2018-03-01

    Aquatic bioconcentration factors (BCFs) are critical in PBT (persistent, bioaccumulative, toxic) and risk assessment of chemicals. High costs and use of more than 100 fish per standard BCF study (OECD 305) call for alternative methods to replace as much in vivo testing as possible. The BCF waiving scheme is a screening tool combining QSAR classifications based on physicochemical properties related to the distribution (hydrophobicity, ionisation), persistence (biodegradability, hydrolysis), solubility and volatility (Henry's law constant) of substances in water bodies and aquatic biota to predict substances with low aquatic bioaccumulation (nonB, BCF<2000). The BCF waiving scheme was developed with a dataset of reliable BCFs for 998 compounds and externally validated with another 181 substances. It performs with 100% sensitivity (no false negatives), >50% efficacy (waiving potential), and complies with the OECD principles for valid QSARs. The chemical applicability domain of the BCF waiving scheme is given by the structures of the training set, with some compound classes explicitly excluded like organometallics, poly- and perfluorinated compounds, aromatic triphenylphosphates, surfactants. The prediction confidence of the BCF waiving scheme is based on applicability domain compliance, consensus modelling, and the structural similarity with known nonB and B/vB substances. Compounds classified as nonB by the BCF waiving scheme are candidates for waiving of BCF in vivo testing on fish due to low concern with regard to the B criterion. The BCF waiving scheme supports the 3Rs with a possible reduction of >50% of BCF in vivo testing on fish. If the target chemical is outside the applicability domain of the BCF waiving scheme or not classified as nonB, further assessments with in silico, in vitro or in vivo methods are necessary to either confirm or reject bioaccumulative behaviour. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. LEVELS OF SYNTHETIC MUSK COMPOUNDS IN MUNICIPAL WASTEWATER FOR ESTIMATING BIOTA EXPOSURE IN RECEIVING WATER

    EPA Science Inventory

    To test the ruggedness of a newly developed analytical method for synthetic musks, a 1-year monthly monitoring of synthetic musks in water and biota was conducted for Lake

    Mead (near Las Vegas, Nevada) as well as for combined sewage-dedicated effluent streams feeding Lake ...

  1. From peds to paradoxes: Linkages between soil biota and their influences on ecological processes

    Treesearch

    David C. Coleman

    2008-01-01

    Soils and their biota have been studied by a variety of observational and experimental methods that have allowed biologists to infer their structural and functional interactions. Viewing progress made over the last 10 years, it is apparent that an increasing diversity of analytical and chemical methods are providing much more detailed information about feeding...

  2. Water-quality assessment of the New England Coastal Basins in Maine, Massachusetts, New Hampshire, and Rhode Island : environmental settings and implications for water quality and aquatic biota

    USGS Publications Warehouse

    Flanagan, Sarah M.; Nielsen, Martha G.; Robinson, Keith W.; Coles, James F.

    1999-01-01

    The New England Coastal Basins in Maine, Massachusetts, New Hampshire, and Rhode Island constitute one of 59 study units selected for water-quality assessment as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program. England Coastal Basins study unit encompasses the fresh surface waters and ground waters in a 23,000 square-mile area that drains to the Atlantic Ocean. Major basins include those of the Kennebec, Androscoggin, Saco, Merrimack, Charles, Blackstone, Taunton, and Pawcatuck Rivers. Defining the environmental setting of the study unit is the first step in designing and conducting a multi-disciplinary regional water-quality assessment. The report describes the natural and human factors that affect water quality in the basins and includes descriptions of the physiography, climate, geology, soils, surface- and ground-water hydrology, land use, and the aquatic ecosystem. Although surface-water quality has greatly improved over the past 30 years as a result of improved wastewater treatment at municipal and industrial wastewater facilities, a number of water-quality problems remain. Industrial and municipal wastewater discharges, combined sewer overflows, hydrologic modifications from dams and water diversions, and runoff from urban land use are the major causes of water-quality degradation in 1998. The most frequently detected contaminants in ground water in the study area are volatile organic compounds, petroleum-related products, nitrates, and chloride and sodium. Sources of these contaminants include leaking storage tanks, accidental spills, landfills, road salting, and septic systems and lagoons. Elevated concentrations of mercury are found in fish tissue from streams and lakes throughout the study area.

  3. The chemical response of particle-associated contaminants in aquatic sediments to urbanization in New England, U.S.A.

    NASA Astrophysics Data System (ADS)

    Chalmers, A. T.; Van Metre, P. C.; Callender, E.

    2007-04-01

    Relations between urbanization and particle-associated contaminants in New England were evaluated using a combination of samples from sediment cores, streambed sediments, and suspended stream sediments. Concentrations of PAHs, PCBs, DDT, and seven trace metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn) were correlated strongly with urbanization, with the strongest relations to percentage commercial, industrial, and transportation (CIT) land use. Average PAH and metal concentrations in the most urbanized watersheds were approximately 30 and 6 times the reference concentrations, respectively, in remote, undeveloped watersheds. One-quarter to one-half of sampling sites had concentrations of PAHs, Cu, Pb, or Zn above the probable effects concentration, a set of sediment quality guidelines for adverse effects to aquatic biota, and sediments were predicted to be toxic, on average, when CIT land use exceeded about 10%. Trends in metals in cores from urban watersheds were dominantly downward, whereas trends in PAHs in a suburban watershed were upward. A regional atmospheric-fallout gradient was indicated by as much as order-of-magnitude-greater concentrations and accumulation rates of contaminants in cores from an undeveloped reference lake in Boston compared to those from remote reference watersheds. Contaminant accumulation rates in the lakes with urbanization in their watersheds, however, were 1-3 orders of magnitude greater than those of reference lakes, which indicate the dominance of local sources and fluvial transport of contaminants to urban lakes. These analyses demonstrate the magnitude of urban contamination of aquatic systems and air sheds, and suggest that, despite reductions in contaminant emissions in urban settings, streams and lakes will decline in quality as urbanization of their watersheds takes place.

  4. The chemical response of particle-associated contaminants in aquatic sediments to urbanization in New England, U.S.A.

    USGS Publications Warehouse

    Chalmers, A.T.; Van Metre, P.C.; Callender, E.

    2007-01-01

    Relations between urbanization and particle-associated contaminants in New England were evaluated using a combination of samples from sediment cores, streambed sediments, and suspended stream sediments. Concentrations of PAHs, PCBs, DDT, and seven trace metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn) were correlated strongly with urbanization, with the strongest relations to percentage commercial, industrial, and transportation (CIT) land use. Average PAH and metal concentrations in the most urbanized watersheds were approximately 30 and 6 times the reference concentrations, respectively, in remote, undeveloped watersheds. One-quarter to one-half of sampling sites had concentrations of PAHs, Cu, Pb, or Zn above the probable effects concentration, a set of sediment quality guidelines for adverse effects to aquatic biota, and sediments were predicted to be toxic, on average, when CIT land use exceeded about 10%. Trends in metals in cores from urban watersheds were dominantly downward, whereas trends in PAHs in a suburban watershed were upward. A regional atmospheric-fallout gradient was indicated by as much as order-of-magnitude-greater concentrations and accumulation rates of contaminants in cores from an undeveloped reference lake in Boston compared to those from remote reference watersheds. Contaminant accumulation rates in the lakes with urbanization in their watersheds, however, were 1-3 orders of magnitude greater than those of reference lakes, which indicate the dominance of local sources and fluvial transport of contaminants to urban lakes. These analyses demonstrate the magnitude of urban contamination of aquatic systems and air sheds, and suggest that, despite reductions in contaminant emissions in urban settings, streams and lakes will decline in quality as urbanization of their watersheds takes place. ?? 2006 Elsevier B.V. All rights reserved.

  5. Aquatic Plant Control Research Program. Allelopathic Aquatic Plants for Aquatic Plant Management: A Feasibility Study

    DTIC Science & Technology

    1989-10-01

    1978. " Ecotoxicology of aquatic plant communi- ties," Principles of Ecotoxicology , SCOPE Report 12, Chapter 11, pp 239-255. [Heavy metals, Pollutants...Phragmites communis and Equisetum limosum were cultivated . They found plant-plant influences depend on soil type. Typha latifolia, S. A2 lacustris, and

  6. When the Fog Clears: Long-Term Monitoring of Fog and Fog-Dependent Biota in the Namib Desert

    NASA Astrophysics Data System (ADS)

    Logan, J. R. V.

    2014-12-01

    The Gobabeb Research and Training Centre in western Namibia is currently undertaking several efforts to enhance long-term atmospheric and fog monitoring in the central Namib Desert and to measure how fog-dependent biota are responding to global change. In an environment that receives regular sea fog and a mean annual rainfall of only 25 mm, Gobabeb is ideally situated to study the drivers and ecological role of fog in arid environments. Currently more than ten meteorological projects perform measurements at or close to Gobabeb. These projects include continuous trace gas measurements, fog isotope sampling, in situ surface radiation measurements, land surface temperature and other satellite validation studies, and multiple aerosol/dust monitoring projects; most of these projects are also components in other global monitoring networks. To these projects, Gobabeb has recently added a network of nine autonomous weather stations spanning the central Namib that will continuously collect basic meteorological data over an area of approximately 70x70 km. Using this data in conjunction with modeling efforts will expand our understanding of fog formation and the linkages between fog and the Benguela Current off Namibia's coast. Historical weather data from previous meteorological stations and satellite observations will also enable development of a fog time series for the last 50 years to determine climate variability driven by possible changes in the Benguela Current system. To complement these efforts, Gobabeb is also expanding its decades-old ecological research programs to explore the impacts of the fog on the region's biota at various time and spatial scales. Gobabeb's long-term, multidisciplinary projects can serve as a prototype for monitoring in other fog-affected systems, together increasing our understanding of coastal fog dynamics, land-atmosphere-ocean connections, and the impacts of fog-related global change.

  7. Recruitment of marine biota onto hard and soft artificially created subtidal habitats in Sabah Al-Ahmad Sea City, Kuwait.

    PubMed

    Jones, David A; Nithyanandan, Manickam

    2013-07-30

    Remediation of coastal habitats from impacts such as dredging and excavation in Gulf coastal waters is hampered by a lack of information on natural recolonisation rates and recruitment patterns of subtidal biota. For soft substrate habitats recovery information is only available for severely polluted sites where recovery takes many years (Jones et al., 2008). Construction of the Sabah Al-Ahmad Sea City provides a unique opportunity to follow benthic recruitment and community development on a range of artificially created benthic habitats over time. The three phases completed were each flooded by the sea separately and annual ecological surveys allow comparison of colonisation patterns and community development rates over time. Species diversity similar to that seen in comparable natural open sea habitats is reached within 2-5 years for mixed sand/rock biota, but longer (2-6 years) for sand biota. Biotic abundance exceeds open sea levels within 1-2 years due to settlement of opportunistic species. Coral recruitment occurred within 3 years. Present data provides a reference point for recovery rates into none polluted benthic habitats for the Gulf. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Preliminary Problem Definition Study of 48 Munitions-Related Chemicals. Volume II. Propellant-Related Chemicals

    DTIC Science & Technology

    1978-04-01

    34analysis of sediment and biota samples from Radford AAP aquatic toxicity studies if the literature evaluation reveals the need for more information... Sampling and analysis at Radford be performed to determine the quantity of the compound entering the New River Best Available Co. -7- V - A literature...chemical properties of this compound if they can not be obtained from the manufacturer - Sampling and analysis of sediment and biota at Radford AAP to

  9. Chesapeake Bay Low Freshwater Inflow Study. Biota Assessment. Phase II. Main Report.

    DTIC Science & Technology

    1982-05-01

    organisms in shallow water with a sensitive life stage occurring in the spring of the year. This indicates that aquatic vegetation and sessile animals are...variety of animals, primarily waterfowl and aquatic mammals, although the fresh water marsh species are primarily used directly. The major pathway through...of the diverse freshwater /oligohaline SAV community, all of which would be *: similarly impacted by fresh water inflow reductions. In addition, input

  10. Three responses to small changes in stream temperature by autumn-emerging aquatic insects

    Treesearch

    Judith L. Li; Sherri L. Johnson; Janel Banks Sobota

    2011-01-01

    In this experimental study, conducted in coastal Oregon USA, we examined how small increases in summer water temperatures affected aquatic insect growth and autumn emergence. We maintained naturally fluctuating temperatures from 2 nearby streams and a 3rd regime, naturally fluctuating temperatures warmed by 3-5°C, in flow-through troughs from mid...

  11. Aquatic Plants Aid Sewage Filter

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.

    1985-01-01

    Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

  12. A review of ecological effects and environmental fate of illicit drugs in aquatic ecosystems.

    PubMed

    Rosi-Marshall, E J; Snow, D; Bartelt-Hunt, S L; Paspalof, A; Tank, J L

    2015-01-23

    Although illicit drugs are detected in surface waters throughout the world, their environmental fate and ecological effects are not well understood. Many illicit drugs and their breakdown products have been detected in surface waters and temporal and spatial variability in use translates into "hot spots and hot moments" of occurrence. Illicit drug occurrence in regions of production and use and areas with insufficient wastewater treatment are not well studied and should be targeted for further study. Evidence suggests that illicit drugs may not be persistent, as their half-lives are relatively short, but may exhibit "pseudo-persistence" wherein continual use results in persistent occurrence. We reviewed the literature on the ecological effects of these compounds on aquatic organisms and although research is limited, a wide array of aquatic organisms, including bacteria, algae, invertebrates, and fishes, have receptors that make them potentially sensitive to these compounds. In summary, illicit drugs occur in surface waters and aquatic organisms may be affected by these compounds; research is needed that focuses on concentrations of illicit drugs in areas of production and high use, environmental fate of these compounds, and effects of these compounds on aquatic ecosystems at the concentrations that typically occur in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Aquatic Sediments.

    ERIC Educational Resources Information Center

    Sanville, W. D.; And Others

    1978-01-01

    Presents a literature review of aquatic sediments and its effect upon water quality, covering publications of 1976-77. This review includes: (1) sediment water interchange; (2) chemical and physical characterization; and (3) heavy water in sediments. A list of 129 references is also presented. (HM)

  14. Effects of Cu Pollution on the Expansion of an Amphibious Clonal Herb in Aquatic-Terrestrial Ecotones.

    PubMed

    Xu, Liang; Zhou, Zhen-Feng

    2016-01-01

    Physiological integration can enhance the performance of clonal plants in aquatic and terrestrial heterogeneous habitats and associated ecotones. Similar to nutrients, pollutants may be transported among connected ramets via physiological integration. Few studies have examined the expansion of amphibious clonal plants from terrestrial to aquatic environments, particularly when the local water supply is polluted with heavy metals. A greenhouse experiment was conducted using the amphibious plant Alternanthera philoxeroides to determine whether Cu can spread among clonal plants and examine the corresponding effects of this pollution on the expansion of clonal plants in aquatic-terrestrial ecotones. Ramets from the same clonal fragments were rooted in unpolluted soil and polluted water at five different levels. The responses of the ramets in terrestrial and aquatic habitats were quantified via traits associated with growth, morphology and Cu accumulation. The results indicated that ramets in soil and water significantly differed in nearly all of these traits. The expansion of populations from terrestrial to polluted aquatic habitats was facilitated by stem elongation rather than new ramet production. The accumulated Cu in polluted ramets can be horizontally transported to other ramets in soil via connected stolons. In terms of clonal growth patterns, variations in Cu pollution intensity were negatively correlated with variations in the morphological and growth traits of ramets in polluted aquatic habitats and unpolluted soil. We concluded that Cu ions are distributed among the clones and accumulated in different ramet tissues in heterogeneous habitats. Therefore, we suggest that Cu pollution of aquatic-terrestrial ecotones, especially at high levels, can affect the growth and expansion of the whole clones because Cu ions are shared between integrated ramets.

  15. Effects of Cu Pollution on the Expansion of an Amphibious Clonal Herb in Aquatic-Terrestrial Ecotones

    PubMed Central

    Zhou, Zhen-Feng

    2016-01-01

    Physiological integration can enhance the performance of clonal plants in aquatic and terrestrial heterogeneous habitats and associated ecotones. Similar to nutrients, pollutants may be transported among connected ramets via physiological integration. Few studies have examined the expansion of amphibious clonal plants from terrestrial to aquatic environments, particularly when the local water supply is polluted with heavy metals. A greenhouse experiment was conducted using the amphibious plant Alternanthera philoxeroides to determine whether Cu can spread among clonal plants and examine the corresponding effects of this pollution on the expansion of clonal plants in aquatic-terrestrial ecotones. Ramets from the same clonal fragments were rooted in unpolluted soil and polluted water at five different levels. The responses of the ramets in terrestrial and aquatic habitats were quantified via traits associated with growth, morphology and Cu accumulation. The results indicated that ramets in soil and water significantly differed in nearly all of these traits. The expansion of populations from terrestrial to polluted aquatic habitats was facilitated by stem elongation rather than new ramet production. The accumulated Cu in polluted ramets can be horizontally transported to other ramets in soil via connected stolons. In terms of clonal growth patterns, variations in Cu pollution intensity were negatively correlated with variations in the morphological and growth traits of ramets in polluted aquatic habitats and unpolluted soil. We concluded that Cu ions are distributed among the clones and accumulated in different ramet tissues in heterogeneous habitats. Therefore, we suggest that Cu pollution of aquatic-terrestrial ecotones, especially at high levels, can affect the growth and expansion of the whole clones because Cu ions are shared between integrated ramets. PMID:27736932

  16. Aquatic concentrations of chemical analytes compared to ...

    EPA Pesticide Factsheets

    We describe screening level estimates of potential aquatic toxicity posed by 227 chemical analytes that were measured in 25 ambient water samples collected as part of a joint USGS/USEPA drinking water plant study. Measured concentrations were compared to biological effect concentration (EC) estimates, including USEPA aquatic life criteria, effective plasma concentrations of pharmaceuticals, published toxicity data summarized in the USEPA ECOTOX database, and chemical structure-based predictions. Potential dietary exposures were estimated using a generic 3-tiered food web accumulation scenario. For many analytes, few or no measured effect data were found, and for some analytes, reporting limits exceeded EC estimates, limiting the scope of conclusions. Results suggest occasional occurrence above ECs for copper, aluminum, strontium, lead, uranium, and nitrate. Sparse effect data for manganese, antimony, and vanadium suggest that these analytes may occur above ECs, but additional effect data would be desirable to corroborate EC estimates. These conclusions were not affected by bioaccumulation estimates. No organic analyte concentrations were found to exceed EC estimates, but ten analytes had concentrations in excess of 1/10th of their respective EC: triclocarban, norverapamil, progesterone, atrazine, metolachlor, triclosan, para-nonylphenol, ibuprofen, venlafaxine, and amitriptyline, suggesting more detailed characterization of these analytes. Purpose: to provide sc

  17. The evolutionary puzzle of egg size, oxygenation and parental care in aquatic environments.

    PubMed

    Braga Goncalves, Ines; Ahnesjö, Ingrid; Kvarnemo, Charlotta

    2015-08-22

    Offspring fitness generally improves with increasing egg size. Yet, eggs of most aquatic organisms are small. A common but largely untested assumption is that larger embryos require more oxygen than they can acquire through diffusion via the egg surface, constraining egg size evolution. However, we found no detrimental effects of large egg size on embryo growth and survival under hypoxic conditions. We tested this in the broad-nosed pipefish, Syngnathus typhle, whose males provide extensive care (nourishment, osmoregulation and oxygenation) to their young in a brood pouch on their bodies. We took advantage of this species' pronounced variation in egg size, correlating positively with female size, and tested the effect of hypoxia (40% dissolved oxygen) versus fully oxygenated (100%) water on embryo size and survival of large versus small eggs after 18 days of paternal brooding. Egg size did not affect embryo survival, regardless of O2 treatment. While hypoxia affected embryo size negatively, both large and small eggs showed similar reductions in growth. Males in hypoxia ventilated more and males with large eggs swam more, but neither treatment affected their position in the water column. Overall, our results call into question the most common explanation for constrained egg size evolution in aquatic environments. © 2015 The Author(s).

  18. The evolutionary puzzle of egg size, oxygenation and parental care in aquatic environments

    PubMed Central

    Braga Goncalves, Ines; Ahnesjö, Ingrid; Kvarnemo, Charlotta

    2015-01-01

    Offspring fitness generally improves with increasing egg size. Yet, eggs of most aquatic organisms are small. A common but largely untested assumption is that larger embryos require more oxygen than they can acquire through diffusion via the egg surface, constraining egg size evolution. However, we found no detrimental effects of large egg size on embryo growth and survival under hypoxic conditions. We tested this in the broad-nosed pipefish, Syngnathus typhle, whose males provide extensive care (nourishment, osmoregulation and oxygenation) to their young in a brood pouch on their bodies. We took advantage of this species' pronounced variation in egg size, correlating positively with female size, and tested the effect of hypoxia (40% dissolved oxygen) versus fully oxygenated (100%) water on embryo size and survival of large versus small eggs after 18 days of paternal brooding. Egg size did not affect embryo survival, regardless of O2 treatment. While hypoxia affected embryo size negatively, both large and small eggs showed similar reductions in growth. Males in hypoxia ventilated more and males with large eggs swam more, but neither treatment affected their position in the water column. Overall, our results call into question the most common explanation for constrained egg size evolution in aquatic environments. PMID:26290070

  19. Update to the Propagation and Establishment of Aquatic Plants Handbook

    DTIC Science & Technology

    2005-03-01

    decades or even longer. In the interim these reservoirs provide relatively poor aquatic habitat and water quality. Unvegetated aquatic ecosystems are also...establishment or reestab- lishment of aquatic plant communities. Many reservoirs without aquatic plants suffer from poor water quality (high nutrients...serve as a food source for waterfowl and other aquatic wildlife, improve water clarity and quality (James and Barko 1990), reduce rates of

  20. Project WILD: Aquatic Education Activity Guide.

    ERIC Educational Resources Information Center

    Memphis State Univ., TN. Tennessee Administrative Software Clearinghouse.

    Project WILD is an interdisciplinary, supplementary environmental and conservation education program which emphasizes wildlife. This document is one guide developed by Project WILD with the specific purpose of focusing on aquatic wildlife, or any wild animals that depend upon aquatic environments for survival. The book contains instructional…

  1. Amazonian freshwater habitats experiencing environmental and socioeconomic threats affecting subsistence fisheries.

    PubMed

    Alho, Cleber J R; Reis, Roberto E; Aquino, Pedro P U

    2015-09-01

    Matching the trend seen among the major large rivers of the globe, the Amazon River and its tributaries are facing aquatic ecosystem disruption that is affecting freshwater habitats and their associated biodiversity, including trends for decline in fishery resources. The Amazon's aquatic ecosystems, linked natural resources, and human communities that depend on them are increasingly at risk from a number of identified threats, including expansion of agriculture; cattle pastures; infrastructure such as hydroelectric dams, logging, mining; and overfishing. The forest, which regulates the hydrological pulse, guaranteeing the distribution of rainfall and stabilizing seasonal flooding, has been affected by deforestation. Flooding dynamics of the Amazon Rivers are a major factor in regulating the intensity and timing of aquatic organisms. This study's objective was to identify threats to the integrity of freshwater ecosystems, and to seek instruments for conservation and sustainable use, taking principally fish diversity and fisheries as factors for analysis.

  2. A common soil handling technique can generate incorrect estimates of soil biota effects on plants

    USDA-ARS?s Scientific Manuscript database

    Several plant-soil biota (PSB) studies were recently published in high profile journals that used the suspect “mixed soil sampling” methodology. To explore the extent to which mixing field samples (i.e. employing mixed soil sample designs) can generate erroneous conclusions, we used real data to pa...

  3. Nitrous oxide emission by aquatic macrofauna

    PubMed Central

    Stief, Peter; Poulsen, Morten; Nielsen, Lars Peter; Brix, Hans; Schramm, Andreas

    2009-01-01

    A large variety of aquatic animals was found to emit the potent greenhouse gas nitrous oxide when nitrate was present in the environment. The emission was ascribed to denitrification by ingested bacteria in the anoxic animal gut, and the exceptionally high N2O-to-N2 production ratio suggested delayed induction of the last step of denitrification. Filter- and deposit-feeding animal species showed the highest rates of nitrous oxide emission and predators the lowest, probably reflecting the different amounts of denitrifying bacteria in the diet. We estimate that nitrous oxide emission by aquatic animals is quantitatively important in nitrate-rich aquatic environments like freshwater, coastal marine, and deep-sea ecosystems. The contribution of this source to overall nitrous oxide emission from aquatic environments might further increase because of the projected increase of nitrate availability in tropical regions and the numeric dominance of filter- and deposit-feeders in eutrophic ecosystems. PMID:19255427

  4. Stable δ15N and δ13C isotope ratios in aquatic ecosystems

    PubMed Central

    Wada, Eitaro

    2009-01-01

    In the past 20 years, rapid progress in stable isotope (SI) studies has allowed scientists to observe natural ecosystems from entirely new perspectives. This report addresses the fundamental concepts underlying the use of the SI ratio. The unique characteristics of the SI ratio make it an interdisciplinary parameter that acts as a chemical fingerprint of biogenic substances and provides a key to the world of isotopomers. Variations in SI ratios of biogenic substances depend on the isotopic compositions of reactants, the pathways and kinetic modes of reaction dynamics, and the physicochemical conditions. In fact, every biogenic material has its own isotopic composition, its “dynamic SI fingerprint”, which is governed by its function and position in the material flow. For example, the relative SI ratio in biota is determined by dietary lifestyle, e.g., the modes of drinking, eating, and excreting, and appears highly regular due to the physicochemical differences of isotopomers. Our primary goal here is to elucidate the general principals of isotope partitioning in major biophilic elements in molecules, biogenic materials, and ecosystems (Wada, E. et al., 1995). To this end, the nitrogen and carbon SI distribution ratios (δ15N and δ13C, respectively) are used to examine materials cycling, food web structures, and their variability in various kinds of watershed-including aquatic ecosystems to elucidate an “isotopically ordered world”. PMID:19282646

  5. Responses of Aquatic Saproxylic Macroinvertebrates to Reduced-Impact Logging in Central Amazonia.

    PubMed

    Roque, F O; Escarpinati, S C; Valente-Neto, F; Hamada, N

    2015-08-01

    Reduced-impact logging (RIL) is an alternative land use because it reduces damage to forest cover in comparison with clear-cut practices. However, management practices adopted in RIL can affect wood availability and, consequently, fauna associated with dead wood during part of their life cycle (saproxylic). In this study, we evaluated whether aquatic saproxylic macroinvertebrates are affected by reduced-impact logging in Central Amazonia. We selected six streams in areas under reduced-impacted logging and six in primary forest areas and collected submerged woody debris. We did not find any differences in water pH, conductivity, and wood availability between reduced-impacted forest and primary forest streams. We found 248 saproxylic aquatic macroinvertebrates belonging to 37 taxa. We found five wood specialist (Dryops, Lutrochus, Stenochironomus, Oukuriella, and Endotribelos) and 32 generalists, totalling 98 and 150 individuals, respectively. In general, our results show that reduced-impact logging does not affect richness, abundance, and composition of saproxylic macroinvertebrates. The main explanation for this pattern is that management practices do not change important macroinvertebrate niche dimensions, including wood availability and the water's chemical and physical variables. Thus, controlled logging, such as applied in the area of the Central Amazonian streams studied, opens a new prospect for insect conservation and commercial exploitation of wood, which is not possible when clear-cut practices are adopted.

  6. Abiotic variability among different aquatic systems of the central Amazon floodplain during drought and flood events.

    PubMed

    Affonso, A G; Queiroz, H L; Novo, E M L M

    2015-11-01

    This paper examines water properties from lakes, (depression lakes, sensu Junk et al., 2012), channels (scroll lakes with high connectivity, sensu Junk et al., 2012) and paleo-channels (scroll lakes with low connectivity-sensu Junk et al., 2012, locally called ressacas) located in Mamirauá Sustainable Development Reserve, in Central Amazon floodplain, Amazonas, Brazil. We analysed surface temperature, conductivity, pH, dissolved oxygen, turbidity, transparency, suspended inorganic and organic matter, chlorophyll-a, pheophytin, total nitrogen, total phosphorus, organic and inorganic carbon in 2009 high water phase, 2009 and 2010 low water phases. Multivariate statistical analyses of 24 aquatic systems (6 ressacas, 12 lakes and 6 channels, 142 samples) were applied to the variables in order to: 1) quantify differences among aquatic system types; 2) assess how those differences are affected in the different phases of the hydrological year. First, we analysed the entire set of variables to test for differences among phases of the hydrological year and types of aquatic systems using a PERMANOVA two-way crossed design. The results showed that the all measured limnological variables are distinct regarding both factors: types of aquatic systems and hydrological phases. In general, the magnitude and amplitude of all variables were higher in the low water phase than in the high water phase, except for water transparency in all aquatic system's types. PERMANOVA showed that the differences between aquatic system's types and hydrological phases of all variables were highly significant for both main factors (type and phase) and for the type x phase interaction. Limnological patterns of Amazon floodplain aquatic systems are highly dynamic, dependent on the surrounding environment, flood pulse, main river input and system type. These patterns show how undisturbed systems respond to natural variability in such a diverse environment, and how distinct are those aquatic systems

  7. Screening of perfluorinated compounds in water, sediment and biota of the Llobregat River basin (NE Spain)

    NASA Astrophysics Data System (ADS)

    Campo, Julian; Perez, Francisca; Pico, Yolanda; Farre, Marinella; Barcelo, Damia; Andreu, Vicente

    2014-05-01

    PFCs present significant thermal and chemical stability being persistent in the environment, where they can bio-accumulate and adversely affect humans and wildlife (Llorca et al., 2012). Human exposure to PFCs is of concern since PFCs tend to be associated with fatty acid binding proteins in the liver or albumin proteins in blood, and have been detected in human serum, urine, saliva, seminal plasma and breast milk (Sundstrom et al., 2011). This study is aimed at the screening of 21 perfluorinated compounds (PFCs) in environmental samples by high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS). The main objective is to identify target compounds at low levels in water, sediments and biota of the Llobregat River (2010), second longest river in Catalonia and one of Barcelona's major drinking water resources. PFCs were extracted from water samples by Solid Phase Extraction (SPE); from sediment by ultrasonication with acidified methanol followed by an off-line SPE procedure (Picó et al., 2012), and from biota (fish) with alkaline digestion, clean-up by TurboFlow™ on line technology coupled to LC-MS/MS (Llorca et al., 2012). The limits of detection (LODs) and limits of quantification (LOQs) of the method were calculated by analysis of spiked river water, sediment, and biota with minimum concentrations of each individual compound at a signal-to-noise ratio of 3 and 10, respectively. The LODs and LOQs of the method in river water ranged between 0.004 and 0.8 ng L-1 and between 0.01 and 2 ng L-1, respectively. In sediment LODs were 0.013-2.667 ng g-1 dry weight (dw) and LOQs were 0.04-8 ng g-1 dw, meanwhile in biota these were 0.006-0.7 pg μL-1 and 0.02-2.26 pg μL-1, respectively. Recoveries ranged between 65% and 102% for all target compounds. The method was applied to study the spatial distribution of these compounds in the Llobregat River basin. For this, a total of 40 samples were analysed (14 water, 14 sediments, 12 fishes). Of the 21 target

  8. Aquatic Acoustic Metrics Interface

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    2012-12-18

    Fishes and marine mammals may suffer a range of potential effects from exposure to intense underwater sound generated by anthropogenic activities such as pile driving, shipping, sonars, and underwater blasting. Several underwater sound recording (USR) devices have been built to acquire samples of the underwater sound generated by anthropogenic activities. Software becomes indispensable for processing and analyzing the audio files recorded by these USRs. The new Aquatic Acoustic Metrics Interface Utility Software (AAMI) is specifically designed for analysis of underwater sound recordings to provide data in metrics that facilitate evaluation of the potential impacts of the sound on aquatic animals.more » In addition to the basic functions, such as loading and editing audio files recorded by USRs and batch processing of sound files, the software utilizes recording system calibration data to compute important parameters in physical units. The software also facilitates comparison of the noise sound sample metrics with biological measures such as audiograms of the sensitivity of aquatic animals to the sound, integrating various components into a single analytical frame.« less

  9. Microplastic in Aquatic Ecosystems.

    PubMed

    Ivleva, Natalia P; Wiesheu, Alexandra C; Niessner, Reinhard

    2017-02-06

    The contamination of marine and freshwater ecosystems with plastic, and especially with microplastic (MP), is a global ecological problem of increasing scientific concern. This has stimulated a great deal of research on the occurrence of MP, interaction of MP with chemical pollutants, the uptake of MP by aquatic organisms, and the resulting (negative) impact of MP. Herein, we review the major issues of MP in aquatic environments, with the principal aims 1) to characterize the methods applied for MP analysis (including sampling, processing, identification and quantification), indicate the most reliable techniques, and discuss the required further improvements; 2) to estimate the abundance of MP in marine/freshwater ecosystems and clarify the problems that hamper the comparability of such results; and 3) to summarize the existing literature on the uptake of MP by living organisms. Finally, we identify knowledge gaps, suggest possible strategies to assess environmental risks arising from MP, and discuss prospects to minimize MP abundance in aquatic ecosystems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Response of detoxification system genes on Chironomus riparius aquatic larvae after antibacterial agent triclosan exposures.

    PubMed

    Martínez-Paz, Pedro

    2018-05-15

    Triclosan (TCS) is an antimicrobial agent used in a range of personal care and consumer products and is commonly detected in aquatic ecosystems. In the present study, the effects of TCS at the molecular level on the detoxification system of Chironomus riparius aquatic larvae, a test organism widely used for the assessment of aquatic toxicology, were evaluated. The obtained results show that this xenobiotic was able to induce significant changes in transcripts from different cytochrome P450s and glutathione s-transferases genes, involved in phase I and phase II of detoxification system, respectively. In contrast, TCS did not affect the glutathione S-transferase enzyme activity nor the expression pattern of multidrug resistance-associated protein 1, which belongs to phase III of detoxification system. These results provide information about the effects of TCS on the detoxification mechanism of C. riparius and offers different biomarker genes that could be useful in ecotoxicological studies, risk assessment and bioremediation. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Nutrition and training adaptations in aquatic sports.

    PubMed

    Mujika, Iñigo; Stellingwerff, Trent; Tipton, Kevin

    2014-08-01

    The adaptive response to training is determined by the combination of the intensity, volume, and frequency of the training. Various periodized approaches to training are used by aquatic sports athletes to achieve performance peaks. Nutritional support to optimize training adaptations should take periodization into consideration; that is, nutrition should also be periodized to optimally support training and facilitate adaptations. Moreover, other aspects of training (e.g., overload training, tapering and detraining) should be considered when making nutrition recommendations for aquatic athletes. There is evidence, albeit not in aquatic sports, that restricting carbohydrate availability may enhance some training adaptations. More research needs to be performed, particularly in aquatic sports, to determine the optimal strategy for periodizing carbohydrate intake to optimize adaptations. Protein nutrition is an important consideration for optimal training adaptations. Factors other than the total amount of daily protein intake should be considered. For instance, the type of protein, timing and pattern of protein intake and the amount of protein ingested at any one time influence the metabolic response to protein ingestion. Body mass and composition are important for aquatic sport athletes in relation to power-to-mass and for aesthetic reasons. Protein may be particularly important for athletes desiring to maintain muscle while losing body mass. Nutritional supplements, such as b-alanine and sodium bicarbonate, may have particular usefulness for aquatic athletes' training adaptation.

  12. Rainfall changes affect the algae dominance in tank bromeliad ecosystems.

    PubMed

    Pires, Aliny Patricia Flauzino; Leal, Juliana da Silva; Peeters, Edwin T H M

    2017-01-01

    Climate change and biodiversity loss have been reported as major disturbances in the biosphere which can trigger changes in the structure and functioning of natural ecosystems. Nonetheless, empirical studies demonstrating how both factors interact to affect shifts in aquatic ecosystems are still unexplored. Here, we experimentally test how changes in rainfall distribution and litter diversity affect the occurrence of the algae-dominated condition in tank bromeliad ecosystems. Tank bromeliads are miniature aquatic ecosystems shaped by the rainwater and allochthonous detritus accumulated in the bases of their leaves. Here, we demonstrated that changes in the rainfall distribution were able to reduce the chlorophyll-a concentration in the water of bromeliad tanks affecting significantly the occurrence of algae-dominated conditions. On the other hand, litter diversity did not affect the algae dominance irrespective to the rainfall scenario. We suggest that rainfall changes may compromise important self-reinforcing mechanisms responsible for maintaining high levels of algae on tank bromeliads ecosystems. We summarized these results into a theoretical model which suggests that tank bromeliads may show two different regimes, determined by the bromeliad ability in taking up nutrients from the water and by the total amount of light entering the tank. We concluded that predicted climate changes might promote regime shifts in tropical aquatic ecosystems by shaping their structure and the relative importance of other regulating factors.

  13. Rainfall changes affect the algae dominance in tank bromeliad ecosystems

    PubMed Central

    Pires, Aliny Patricia Flauzino; Leal, Juliana da Silva; Peeters, Edwin T. H. M.

    2017-01-01

    Climate change and biodiversity loss have been reported as major disturbances in the biosphere which can trigger changes in the structure and functioning of natural ecosystems. Nonetheless, empirical studies demonstrating how both factors interact to affect shifts in aquatic ecosystems are still unexplored. Here, we experimentally test how changes in rainfall distribution and litter diversity affect the occurrence of the algae-dominated condition in tank bromeliad ecosystems. Tank bromeliads are miniature aquatic ecosystems shaped by the rainwater and allochthonous detritus accumulated in the bases of their leaves. Here, we demonstrated that changes in the rainfall distribution were able to reduce the chlorophyll-a concentration in the water of bromeliad tanks affecting significantly the occurrence of algae-dominated conditions. On the other hand, litter diversity did not affect the algae dominance irrespective to the rainfall scenario. We suggest that rainfall changes may compromise important self-reinforcing mechanisms responsible for maintaining high levels of algae on tank bromeliads ecosystems. We summarized these results into a theoretical model which suggests that tank bromeliads may show two different regimes, determined by the bromeliad ability in taking up nutrients from the water and by the total amount of light entering the tank. We concluded that predicted climate changes might promote regime shifts in tropical aquatic ecosystems by shaping their structure and the relative importance of other regulating factors. PMID:28422988

  14. New tools for aquatic habitat modeling

    Treesearch

    D. Tonina; J. A. McKean; C. Tang; P. Goodwin

    2011-01-01

    Modeling of aquatic microhabitat in streams has been typically done over short channel reaches using one-dimensional simulations, partly because of a lack of high resolution. subaqueous topographic data to better define model boundary conditions. The Experimental Advanced Airborne Research Lidar (EAARL) is an airborne aquatic-terrestrial sensor that allows simultaneous...

  15. Stimulation of microbial nitrogen cycling in aquatic ecosystems by benthic macrofauna: mechanisms and environmental implications

    NASA Astrophysics Data System (ADS)

    Stief, P.

    2013-12-01

    Invertebrate animals that live at the bottom of aquatic ecosystems (i.e., benthic macrofauna) are important mediators between nutrients in the water column and microbes in the benthos. The presence of benthic macrofauna stimulates microbial nutrient dynamics through different types of animal-microbe interactions, which potentially affect the trophic status of aquatic ecosystems. This review contrasts three types of animal-microbe interactions in the benthos of aquatic ecosystems: (i) ecosystem engineering, (ii) grazing, and (iii) symbiosis. Their specific contributions to the turnover of fixed nitrogen (mainly nitrate and ammonium) and the emission of the greenhouse gas nitrous oxide are evaluated. Published data indicate that ecosystem engineering by sediment-burrowing macrofauna stimulates benthic nitrification and denitrification, which together allows fixed nitrogen removal. However, the release of ammonium from sediments is enhanced more strongly than the sedimentary uptake of nitrate. Ecosystem engineering by reef-building macrofauna increases nitrogen retention and ammonium concentrations in shallow aquatic ecosystems, but allows organic nitrogen removal through harvesting. Grazing by macrofauna on benthic microbes apparently has small or neutral effects on nitrogen cycling. Animal-microbe symbioses provide abundant and distinct benthic compartments for a multitude of nitrogen-cycle pathways. Recent studies reveal that ecosystem engineering, grazing, and symbioses of benthic macrofauna significantly enhance nitrous oxide emission from shallow aquatic ecosystems. The beneficial effect of benthic macrofauna on fixed nitrogen removal through coupled nitrification-denitrification can thus be offset by the concurrent release of (i) ammonium that stimulates aquatic primary production and (ii) nitrous oxide that contributes to global warming. Overall, benthic macrofauna intensifies the coupling between benthos, pelagial, and atmosphere through enhanced turnover and

  16. Stimulation of microbial nitrogen cycling in aquatic ecosystems by benthic macrofauna: mechanisms and environmental implications

    NASA Astrophysics Data System (ADS)

    Stief, P.

    2013-07-01

    Invertebrate animals that live at the bottom of aquatic ecosystems (i.e., benthic macrofauna) are important mediators between nutrients in the water column and microbes in the benthos. The presence of benthic macrofauna stimulates microbial nutrient dynamics through different types of animal-microbe interactions, which potentially affect the trophic status of aquatic ecosystems. This review contrasts three types of animal-microbe interactions in the benthos of aquatic ecosystems: (i) ecosystem engineering, (ii) grazing, and (iii) symbiosis. Their specific contributions to the turnover of fixed nitrogen (mainly nitrate and ammonium) and the emission of the greenhouse gas nitrous oxide are evaluated. Published data indicate that ecosystem engineering by sediment-burrowing macrofauna stimulates benthic nitrification and denitrification, which together allows fixed nitrogen removal. However, the release of ammonium from sediments often is enhanced even more than the sedimentary uptake of nitrate. Ecosystem engineering by reef-building macrofauna increases nitrogen retention and ammonium concentrations in shallow aquatic ecosystems, but allows organic nitrogen removal through harvesting. Grazing by macrofauna on benthic microbes apparently has small or neutral effects on nitrogen cycling. Animal-microbe symbioses provide abundant and distinct benthic compartments for a multitude of nitrogen-cycle pathways. Recent studies revealed that ecosystem engineering, grazing, and symbioses of benthic macrofauna significantly enhance nitrous oxide emission from shallow aquatic ecosystems. The beneficial effect of benthic macrofauna on fixed nitrogen removal through coupled nitrification-denitrification can thus be offset by the concurrent release of (i) ammonium that stimulates aquatic primary production and (ii) nitrous oxide that contributes to global warming. Overall, benthic macrofauna intensifies the coupling between benthos, pelagial, and atmosphere through enhanced turnover

  17. Impact of Imidacloprid for control of Hemlock Woolly Adelgid on nearby aquatic macroinvertebrate asseblages.

    Treesearch

    Melissa Churchel; James Hanula; C. Wayne Berisford; James Vose; Mark Dalusky

    2011-01-01

    Imidacloprid, a systemic insecticide that acts on the nervous system, is currently being used to control hemlock woolly adelgid (Adelges tsugae Annand), which is damaging hemlock trees. The objective of this study was to determine whether soil injection with imidacloprid for hemlock woolly adelgid control near streams adversely affects aquatic invertebrates. Eastern...

  18. Aquatic exercise and pain neurophysiology education versus aquatic exercise alone for patients with chronic low back pain: a randomized controlled trial.

    PubMed

    Pires, Diogo; Cruz, Eduardo Brazete; Caeiro, Carmen

    2015-06-01

    The aim of this study was to compare the effectiveness of a combination of aquatic exercise and pain neurophysiology education with aquatic exercise alone in chronic low back pain patients. Single-blind randomized controlled trial. Outpatient clinic. Sixty-two chronic low back pain patients were randomly allocated to receive aquatic exercise and pain neurophysiology education (n = 30) or aquatic exercise alone (n = 32). Twelve sessions of a 6-week aquatic exercise programme preceded by 2 sessions of pain neurophysiology education. Controls received only 12 sessions of the 6-week aquatic exercise programme. The primary outcomes were pain intensity (Visual Analogue Scale) and functional disability (Quebec Back Pain Disability Scale) at the baseline, 6 weeks after the beginning of the aquatic exercise programme and at the 3 months follow-up. Secondary outcome was kinesiophobia (Tampa Scale of Kinesiophobia). Fifty-five participants completed the study. Analysis using mixed-model ANOVA revealed a significant treatment condition interaction on pain intensity at the 3 months follow-up, favoring the education group (mean SD change: -25.4± 26.7 vs -6.6 ± 30.7, P < 0.005). Although participants in the education group were more likely to report perceived functional benefits from treatment at 3 months follow-up (RR=1.63, 95%CI: 1.01-2.63), no significant differences were found in functional disability and kinesiophobia between groups at any time. This study's findings support the provision of pain neurophysiology education as a clinically effective addition to aquatic exercise. © The Author(s) 2014.

  19. Internal and External Dispersal of Plants by Animals: An Aquatic Perspective on Alien Interference

    PubMed Central

    van Leeuwen, Casper H. A.

    2018-01-01

    Many alien plants use animal vectors for dispersal of their diaspores (zoochory). If alien plants interact with native disperser animals, this can interfere with animal-mediated dispersal of native diaspores. Interference by alien species is known for frugivorous animals dispersing fruits of terrestrial plants by ingestion, transport and egestion (endozoochory). However, less attention has been paid to possible interference of alien plants with dispersal of diaspores via external attachment (ectozoochory, epizoochory or exozoochory), interference in aquatic ecosystems, or positive effects of alien plants on dispersal of native plants. This literature study addresses the following hypotheses: (1) alien plants may interfere with both internal and external animal-mediated dispersal of native diaspores; (2) interference also occurs in aquatic ecosystems; (3) interference of alien plants can have both negative and positive effects on native plants. The studied literature revealed that alien species can comprise large proportions of both internally and externally transported diaspores. Because animals have limited space for ingested and adhering diaspores, alien species affect both internal and external transport of native diaspores. Alien plant species also form large proportions of all dispersed diaspores in aquatic systems and interfere with dispersal of native aquatic plants. Alien interference can be either negative (e.g., through competition with native plants) or positive (e.g., increased abundance of native dispersers, changed disperser behavior or attracting additional disperser species). I propose many future research directions, because understanding whether alien plant species disrupt or facilitate animal-mediated dispersal of native plants is crucial for targeted conservation of invaded (aquatic) plant communities. PMID:29487609

  20. Aquatic ecosystems of the redwood region

    Treesearch

    Hartwell H. Welsh; T.D. Roelofs; C.A. Frissell

    2000-01-01

    The primary purpose of this chapter is to describe aquatic ecosystems within the redwood region and discuss related management and conservation issues. Although scientists from many disciplines have conducted research in the redwood region, few comprehensive interdisciplinary studies exist (but see Ziemer 1998b) and no regionwide overview or synthesis of the aquatic...