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Sample records for aquatic bioaccumulation model

  1. Modelling bioaccumulation of oil constituents in aquatic species

    NARCIS (Netherlands)

    Hoop, de L.; Huijbregts, M.A.J.; Schipper, A.M.; Veltman, K.; Laender, de F.; Viaene, K.P.J.; Klok, C.; Hendriks, A.J.

    2013-01-01

    Crude oil poses a risk to marine ecosystems due to its toxicity and tendency to accumulate in biota. The present study evaluated the applicability of the OMEGA model for estimating oil accumulation in aquatic species by comparing model predictions of kinetic rates (absorption and elimination) and bi

  2. Modeling the role of microplastics in Bioaccumulation of organic chemicals to marine aquatic organisms. Critical Review

    NARCIS (Netherlands)

    Koelmans, A.A.

    2015-01-01

    It has been shown that ingestion of microplastics may increase bioaccumulation of organic chemicals by aquatic organisms. This paper critically reviews the literature on the effects of plastic ingestion on the bioaccumulation of organic chemicals, emphasizing quantitative approaches and mechanistic

  3. Cyanotoxins: Bioaccumulation and Effects on Aquatic Animals

    Directory of Open Access Journals (Sweden)

    Betina Kozlowsky-Suzuki

    2011-12-01

    Full Text Available Cyanobacteria are photosynthetic prokaryotes with wide geographic distribution that can produce secondary metabolites named cyanotoxins. These toxins can be classified into three main types according to their mechanism of action in vertebrates: hepatotoxins, dermatotoxins and neurotoxins. Many studies on the effects of cyanobacteria and their toxins over a wide range of aquatic organisms, including invertebrates and vertebrates, have reported acute effects (e.g., reduction in survivorship, feeding inhibition, paralysis, chronic effects (e.g., reduction in growth and fecundity, biochemical alterations (e.g., activity of phosphatases, GST, AChE, proteases, and behavioral alterations. Research has also focused on the potential for bioaccumulation and transferring of these toxins through the food chain. Although the herbivorous zooplankton is hypothesized as the main target of cyanotoxins, there is not unquestionable evidence of the deleterious effects of cyanobacteria and their toxins on these organisms. Also, the low toxin burden in secondary consumers points towards biodilution of microcystins in the food web as the predominant process. In this broad review we discuss important issues on bioaccumulation and the effects of cyanotoxins, with emphasis on microcystins, as well as drawbacks and future needs in this field of research.

  4. Bioaccumulation in aquatic systems: methodological approaches, monitoring and assessment

    DEFF Research Database (Denmark)

    Schäfer, Sabine; Buchmeier, Georgia; Claus, Evelyn;

    2015-01-01

    Bioaccumulation, the accumulation of a chemical in an organism relative to its level in the ambient medium, is of major environmental concern. Thus, monitoring chemical concentrations in biota are widely and increasingly used for assessing the chemical status of aquatic ecosystems. In this paper...... temporal and geographical range. Bioaccumulation is also assessed for regulation of chemicals of environmental concern whereby mainly data from laboratory studies on fish bioaccumulation are used. Field data can, however, provide additional important information for regulators. Strategies......, various scientific and regulatory aspects of bioaccumulation in aquatic systems and the relevant critical issues are discussed. Monitoring chemical concentrations in biota can be used for compliance checking with regulatory directives, for identification of chemical sources or event-related environmental...

  5. Arsenic and mercury bioaccumulation in the aquatic plant, Vallisneria neotropicalis.

    Science.gov (United States)

    Lafabrie, C; Major, K M; Major, C S; Cebrián, J

    2011-03-01

    Arsenic (As) and mercury (Hg) are among the most toxic metals/metalloids. The overall goal of this study was to investigate the bioaccumulation of these trace elements in Vallisneria neotropicalis, a key trophic species in aquatic environments. For this purpose, As and Hg concentrations were determined in sediments and natural populations of V. neotropicalis in sub-estuaries of Mobile Bay (Alabama, USA), differing with respect to past and present anthropogenic impact. Analyses indicate that the Fish River is the most contaminated among the sub-estuaries investigated; levels of As found in Fish River sediments fall within a range that could potentially cause adverse effects in biota. Sediment As concentrations were only moderately correlated with those in V. neotropicalis; no correlation was found between sediment and plant Hg levels. However, several parameters could have masked such potential relationships (e.g., differences in sediment characteristics and "biological dilution" phenomena). Results presented herein highlight the numerous parameters that can influence metal/metalloids accumulation in aquatic plants as well as species-specific responses to trace element contamination. Finally, this study underscores the need for further investigation into contaminant bioaccumulation in ecologically and economically important coastal environments. PMID:21168896

  6. Bioaccumulation factors in aquatic ecosystems. A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Sara; Meili, Markus; Bergstroem, Ulla [Studsvik Eco and Safety AB, Nykoeping (Sweden)

    2002-07-01

    The calculated concentrations of radionuclides in organisms are often obtained by means of bioaccumulation factors (BAF) that describe the internal concentration relative to an external concentration e.g. in the abiotic environments at steady-state conditions. Such factors are often used when modelling the dose to man from radio-nuclides released to the biosphere. Values of bioaccumulation factors vary widely in magnitude among elements, organisms, and environmental conditions which is not always considered. In order to relate the bioaccumulation factors for some radionuclides to environmental conditions as well as to the trophic level of the organism of concern we have compiled an extensive database with bioaccumulation factors (about 5,500 values) together with information on some environmental conditions. The data for nine radionuclides has been extracted and examined. A comparison between the bioaccumulation factors found in this study and values given in literature by IAEA and NCRP shows that the ranges presented in this study are generally somewhat higher with the exception of BAF for molybdenum in freshwater fish which is of the same order of magnitude. This is startling and calls for a thorough research. The amount of readily accessible and reliable values of BAF is limited, often because basic information such as e.g. units and part of organism examined, is not reported. This is surprising and also unfortunate for those who need such data for use in generic or specific models. A major update of recommended values appears to be necessary for many elements to account for the development of analytical methods and experiences from case studies over the past two decades.

  7. A method for partitioning cadmium bioaccumulated in small aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardena, S.N.; Rana, K.J.; Baird, D.J. [Univ. of Stirling (United Kingdom). Institute of Aquaculture

    1995-09-01

    A series of laboratory experiments was conducted to evaluate bioaccumulation and surface adsorption of aqueous cadmium (Cd) by sac-fry of the African tilapia Oreochromis niloticus. In the first experiment, the design consisted of two cadmium treatments: 15 {micro}g Cd{center_dot}L{sup {minus}1} in dilution water and a Cd-ethylenediaminetetraacetic acid (Cd-EDTA) complex at 15 {micro}m{center_dot}L{sup {minus}1}, and a water-only control. There were five replicates per treatment and 40 fish per replicate. It was found that EDTA significantly reduced the bioaccumulation of cadmium by tilapia sac-fry by 34%. Based on the results, a second experiment was conducted to evaluate four procedures: a no-rinse control; rinsing in EDTA; rinsing in distilled water; and rinsing in 5% nitric acid, for removing surface-bound Cd from exposed sac-fry. In this experiment, 30 fish in each of five replicates were exposed to 15 {micro}g Cd{center_dot}L{sup {minus}1} for 72 h, processed through the rinse procedures, and analyzed for total Cd. The EDTA rinse treatment significantly reduced (p<0.05) Cd concentrations of the exposed fish relative to those receiving no rinse. It was concluded that the EDTA rinse technique may be useful in studies evaluating the partitioning of surface-bound and accumulated cadmium in small aquatic organisms.

  8. A closer look at bioaccumulation of petroleum hydrocarbon mixtures in aquatic worms.

    NARCIS (Netherlands)

    Muijs, B.; Jonker, M.T.O.

    2010-01-01

    Petroleum hydrocarbons (oils) are ubiquitous in the aquatic environment, and adequate risk assessment is thus essential. Bioaccumulation plays a key role in risk assessment, but the current knowledge on bioaccumulation of oils is limited. Therefore, this process was studied in detail, using the aqua

  9. Bioaccumulation of metals in aquatic insects of streams located in areas with sugar cane cultivation

    OpenAIRE

    Juliano José Corbi; Claudio Gilberto Froehlich; Susana Trivinho Strixino; Ademir dos Santos

    2010-01-01

    Streams located in areas of sugar cane cultivation receive elevated concentrations of metal ions from soils of adjacent areas. The accumulation of metals in the sediments results in environmental problems and leads to bioaccumulation of metal ions by the aquatic organisms. In the present study, bioaccumulation of the metals ions Al, Cd, Cr, Cu, Fe, Mg, Mn and Zn in aquatic insects in streams impacted by the sugar cane was evaluated. The results pointed out that the insects were contaminated b...

  10. Bioaccumulation of metals in aquatic insects of streams located in areas with sugar cane cultivation

    Directory of Open Access Journals (Sweden)

    Juliano José Corbi

    2010-01-01

    Full Text Available Streams located in areas of sugar cane cultivation receive elevated concentrations of metal ions from soils of adjacent areas. The accumulation of metals in the sediments results in environmental problems and leads to bioaccumulation of metal ions by the aquatic organisms. In the present study, bioaccumulation of the metals ions Al, Cd, Cr, Cu, Fe, Mg, Mn and Zn in aquatic insects in streams impacted by the sugar cane was evaluated. The results pointed out that the insects were contaminated by the sediment and that the collector organisms as Chironomus species accumulated higher concentration of metals than the predator organisms.

  11. Bioaccumulation and biomagnification potential of pharmaceuticals with a focus to the aquatic environment.

    Science.gov (United States)

    Zenker, Armin; Cicero, Maria Rita; Prestinaci, Francesca; Bottoni, Paola; Carere, Mario

    2014-01-15

    Pharmaceuticals, among the emerging contaminants, are one of the most relevant groups of substances in aquatic ecosystems due to universal use, their chemico-physical properties and known mode of action in aquatic organisms at low concentrations. After administration many drugs and their transformation products are only retained to some extent in wastewater treatment plants therefore entering the aquatic environment in considerable high amounts. The yearly consumption to treat human and animal diseases, also in livestock and aquaculture was estimated to be hundred thousands tons per year leading to high concentrations in surface water of developed countries. Mostly, pharmaceutical residues in effluents of wastewater treatment plants or in the water column of surface waters have been reported, but data about concentrations in the aquatic biota, partitioning of pharmaceuticals to biosolids, soils, and sediments and the bioaccumulation properties are often lacking. Chronic and subtle effects can be expected when aquatic organisms are long term exposed by pseudo-persistent, persistent and accumulative compounds. This review aims to summarize the current state of research about the fate of pharmaceuticals regarding bioconcentration, bioaccumulation and potential biomagnification in aquatic ecosystems. More comprehensive approaches for the evaluation of environmental (ERA) and human health risk assessment (HRA) are included and analytical methods required to detect bioaccumulation of pharmaceuticals are discussed.

  12. Development of predictive models for xenobiotic bioaccumulation in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Trabalka, J.R.; Garten, C.T. Jr.

    1982-10-01

    We evaluated the suitability of existing, simple empirical models developed for aquatic organisms and the question of extending such models to terrestrial systems. Data sets of other investigators were expanded, and edited showing r/sup 2/ values associated with regressions fell significantly. Expansion of the analysis to include nonruminant mammals and birds produced similar conclusions. A simple sorting model based on hydrophobic tendency was able to successfully separate all but one bioaccumulation hazards from groups of organic compounds (N > 100) when the screening criterion was a specified bioconcentration factor for fish/water (in water-only exposure systems or model ecosystems) or mammal-bird/diet (long-term feeding under laboratory conditions). Approximately one-fourth of the chemicals sorted into the hazardous category did not exhibit significant bioaccumulation and the one hazardous material, which would not have been identified as such, was methylmercury. Results indicate that, although a measure of hydrophobicity is a highly satisfactory first approximation indicator for bioaccumulation potential for most organics in both terrestrial and aquatic vertebrates, this potential is frequently controlled by environmental factors and specific metabolic/steric interactions not adequately represented in existing SARs.

  13. Studies on transfer, bioaccumulation and disappearance of glyphosate in the aquatic ecosystem by utilizing 14C tracer technique

    International Nuclear Information System (INIS)

    Studies on transfer, bioaccumulation and disappearance of glyphosate in the aquatic environment were conducted with methods of model tests and outdoor trials in the aquatic ecosystem. The result showed that glyphosate transferred rapidly into sediment and hormwort (Ceratopyllum demersum L.) after applied; and then, it was taken up faster and accumulated more by topmouth gudgeon (Psudorasobora parva) 5-10 days after application. The partitioning coefficient (sediment-water) and bioconcentration factors of glyphosate were 8.59, 27.96 and 45.79, respectively, in day 20. The concentration of glyphosate residue in the aquatic ecosystem followed the order of topmouth gudgeon > hormwort > sediment > water. And it was also indicated that glyphosate transferred and disappeared extremely fast in both pond and river after application

  14. Mercury bioaccumulation along food webs in temperate aquatic ecosystems colonized by aquatic macrophytes in south western France.

    Science.gov (United States)

    Gentès, Sophie; Maury-Brachet, Régine; Guyoneaud, Rémy; Monperrus, Mathilde; André, Jean-Marc; Davail, Stéphane; Legeay, Alexia

    2013-05-01

    Mercury (Hg) is considered as an important pollutant for aquatic systems as its organic form, methylmercury (MeHg), is easily bioaccumulated and bioamplified along food webs. In various ecosystems, aquatic periphyton associated with macrophyte was identified as an important place for Hg storage and methylation by microorganisms. Our study concerns temperate aquatic ecosystems (South Western France) colonized by invasive macrophytes and characterized by high mercury methylation potentials. This work establishes original data concerning Hg bioaccumulation in organisms (plants, crustaceans, molluscs and fish) from five contrasting ecosystems. For low trophic level species, total Hg (THg) concentrations were low (from 27±2ngTHgg(-1)dw in asiatic clam Corbicula fluminea to 418±114ngTHgg(-1)dw in crayfish Procambarus clarkii). THg concentrations in some carnivorous fish (high trophic level) were close to or exceeded the International Marketing Level (IML) with values ranging from 1049±220ngTHgg(-1)dw in pike perch muscle (Sander lucioperca) to 3910±1307ngTHgg(-1)dw in eel muscle (Anguilla Anguilla). Trophic levels for the individuals were also evaluated through stable isotope analysis, and linked to Hg concentrations of organisms. A significant Hg biomagnification (r(2)= 0.9) was observed in the Aureilhan lake, despite the absence of top predator fish. For this site, Ludwigia sp. periphyton, as an entry point of Hg into food webs, is a serious hypothesis which remains to be confirmed. This study provides a first investigation of Hg transfer in the ecosystems of south western France and allows the assessment of the risk associated with the presence of Hg in aquatic food webs.

  15. Bioaccumulation of heavy metals in Mbaa River and the impact on aquatic ecosystem.

    Science.gov (United States)

    Ajima, M N O; Nnodi, P C; Ogo, O A; Adaka, G S; Osuigwe, D I; Njoku, D C

    2015-12-01

    The bioaccumulation and toxic effects of heavy metals have caused ecological damage to aquatic ecosystem. In this study, concentration of heavy metals including zinc, lead, cadmium, iron, and copper were determined in the sediment and water as well as in the muscle, gill, and intestine of two fish species (Pelmatochromis guentheri and Pelmatochromis pulcher) of Mbaa River in Southeastern Nigeria. Samples were collected at three different spots from the river, and the level of heavy metals specified above were determined by atomic absorption spectroscopy (AAS) after a modified wet digestion process. The results indicated that sediment had the highest concentration of the heavy metals investigated while water had the lowest concentration. Fish tissues showed appreciable bioaccumulation of these metals as evidenced by a higher concentration profile when compared with that of water. Furthermore, the concentration of these heavy metals in water and their bioconcentration factor in the fish were above the recommended limit by WHO and FEPA, indicating that Mbaa River along Inyishi may not be suitable for drinking nor the fish safe for human consumption. The study also reveals the use of fish as bioindicator of aquatic environment. PMID:26597816

  16. Medium-chain chlorinated paraffins (MCCPs): a review of bioaccumulation potential in the aquatic environment.

    Science.gov (United States)

    Thompson, Roy; Vaughan, Martin

    2014-01-01

    Chlorinated paraffins (CPs) are high molecular weight organochlorine compounds that have been used in a variety of industrial applications for many years. Medium-chain chlorinated paraffins (MCCPs) (CAS 85535-85-9; Alkanes, C14-17 , chloro) are currently under investigation as potential persistent bioaccumulative toxic (PBT) compounds. In this article, the bioaccumulation potential of MCCPs is assessed using a tiered framework proposed after a recent Society of Environmental Toxicology and Chemistry (SETAC) Pellston Workshop in 2008. The framework proposes the use of physicochemical properties and modeling assessment, bioconcentration/bioaccumulation (BCF/BAF) assessment, biomagnification (BMF) assessment, and trophic magnification factor (TMF) assessment. It is hoped that use of this framework could harmonize and improve the efficiency and effectiveness of the chemical substance evaluation screening process for PBT properties. When applied to MCCPs, the following conclusions were made: empirical physiochemical data is available negating the use of models; laboratory BCFs range from 1000 to 15 000 (growth-corrected lipid normalized values) for 2 MCCP structures; field BAFs were an order of magnitude higher than the trigger criterion for "B status possible"; although results may not meet acceptance criteria for field studies, laboratory-derived BMFs for a number of C14-17 chlorinated alkanes were less than the trigger value of 1 (based on whole-body concentrations) whereas field-derived BMFs were less than 1 (based on lipid corrected values [generally used for field data] excluding one measure for sculpin, [Cottus cognatus]-Diporeia that was based on only one detectable sample); and finally, TMFs were less than the trigger criterion value of 1, which are considered the most convincing evidence for bioaccumulative properties of a compound and the "Gold Standard" measure of bioaccumulation. This article also discusses the uncertainties surrounding the published data

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

    Science.gov (United States)

    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. PMID:22645815

  18. Bioaccumulation dynamics and exposure routes of Cd and Cu among species of aquatic mayflies

    Science.gov (United States)

    Cain, D.; Croteau, M.-N.; Luoma, S.

    2011-01-01

    Consumption of periphyton is a potentially important route of metal exposure to benthic invertebrate grazers. The present study examined the bioaccumulation kinetics of dissolved and dietary Cd and Cu in five species of mayflies (class Insecta). Artificial stream water and benthic diatoms were separately labeled with enriched stable metal isotopes to determine physiological rate constants used by a biokinetic bioaccumulation model. The model was employed to simulate the effects of metal partitioning between water and food, expressed as the bioconcentration factor (BCF), as well as ingestion rate (IR) and metal assimilation efficiency of food (AE), on the relative importance of water and food to metal bioaccumulation. For all test species, the contribution of dietary uptake of Cd and Cu increased with BCF. For a given BCF, the contribution of food to the body burden increased with kuf, the metal uptake rate constant from food that combined variation in IR and AE. To explore the relative importance of water and diet exposure routes under field conditions, we used estimated site-specific aqueous free-ion concentrations to model Cd and Cu accumulation from aqueous exposure, exclusively. The predicted concentrations accounted for less than 5% of the observed concentrations, implying that most bioaccumulated metal was acquired from food. At least for the taxa considered in this study, we conclude that consumption of metal-contaminated periphyton can result in elevated metal body burdens and potentially increase the risk of metal toxicity. ?? 2011 SETAC.

  19. EURL ECVAM Strategy to replace, reduce and refine the use of fish in aquatic toxicity and bioaccumulation testing

    OpenAIRE

    HALDER MARIA ELISABETH; KIENZLER AUDE; Whelan, Maurice; Worth, Andrew

    2014-01-01

    The assessment of aquatic toxicity and bioaccumulation are important components of the environmental hazard and risk assessment of all types of chemicals, and are therefore included in several pieces of European Union and international legislation. In this document, the European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM) outlines approaches which will deliver an impact on the replacement, reduction and refinement (3Rs) of fish tests used for aquatic toxicity...

  20. Reviewing the serotonin reuptake inhibitors (SSRIs) footprint in the aquatic biota: uptake, bioaccumulation and ecotoxicology.

    Science.gov (United States)

    Silva, Liliana J G; Pereira, André M P T; Meisel, Leonor M; Lino, Celeste M; Pena, Angelina

    2015-02-01

    Selective serotonin re-uptake inhibitors (SSRIs) antidepressants are amongst the most prescribed pharmaceutical active substances throughout the world. Their presence, already described in different environmental compartments such as wastewaters, surface, ground and drinking waters, and sediments, and their remarkable effects on non-target organisms justify the growing concern about these emerging environmental pollutants. A comprehensive review of the literature data with focus on their footprint in the aquatic biota, namely their uptake, bioaccumulation and both acute and chronic ecotoxicology is presented. Long-term multigenerational exposure studies, at environmental relevant concentrations and in mixtures of related compounds, such as oestrogenic endocrine disruptors, continue to be sparse and are imperative to better know their environmental impact.

  1. Bioavailability and Bioaccumulation of Metal-Based Engineered Nanomaterials in Aquatic Environments

    DEFF Research Database (Denmark)

    Luoma, Samuel; Khan, Farhan R.; Croteau, Marie-Noelle

    2014-01-01

    Bioavailability of Me-ENMs to aquatic organisms links their release into the environment to ecological implications. Close examination shows some important differences in the conceptual models that define bioavailability for metals and Me-ENMs. Metals are delivered to aquatic animals from Me-ENMs...

  2. Influence of lead-doped hydroponic medium on the adsorption/bioaccumulation processes of lead and phosphorus in roots and leaves of the aquatic macrophyte Eicchornia crassipes.

    Science.gov (United States)

    Espinoza-Quiñones, Fernando R; Módenes, Aparecido Nivaldo; de Oliveira, Ana Paula; Trigueros, Daniela Estelita Goes

    2013-11-30

    In this study, lead bioaccumulation by the living free-floating aquatic macrophyte Eicchornia crassipes in different hydroponic conditions with variations in phosphorus and lead concentrations was investigated. A set of growth experiments in hydroponic media doped with lead and phosphorus within a wide concentration range was performed for 32 days in a greenhouse. All experiments were carried out with periodic replacement of all nutrients and lead. The concentration of lead and nutrients in biomass was determined by synchrotron radiation-excited total reflection X-ray fluorescence. By increasing the lead concentration in the medium, a reduction in biomass growth was observed, but a higher phosphorus retention in roots and leaves was shown at lower lead concentrations. In addition, an increase in the amount of bioaccumulated lead and phosphorus in roots was observed for higher lead and phosphorus concentrations in the medium, reaching saturation values of 4 mg Pb g(-1) and 7 mg P g(-1), respectively. Four non-structural kinetic models were tested, to represent the bioaccumulation of lead and phosphorus in roots. Pseudo-second order and irreversible kinetic models described the lead bioaccumulation data well, however, an irreversible kinetic model better fitted phosphorus uptake in roots.

  3. Bioavailability and bioaccumulation of metal-based engineered nanomaterials in aquatic environments: concepts and processes: chapter 5

    Science.gov (United States)

    Luoma, Samuel N.; Khan, Farhan R.; Croteau, Marie-Noële

    2014-01-01

    Bioavailability of Me-ENMs to aquatic organisms links their release into the environment to ecological implications. Close examination shows some important differences in the conceptual models that define bioavailability for metals and Me-ENMs. Metals are delivered to aquatic animals from Me-ENMs via water, ingestion, and incidental surface exposure. Both metal released from the Me-ENM and uptake of the nanoparticle itself contribute to bioaccumulation. Some mechanisms of toxicity and some of the metrics describing exposure may differ from metals alone. Bioavailability is driven by complex interaction of particle attributes, environmental transformations, and biological traits. Characterization of Me-ENMs is an essential part of understanding bioavailability and requires novel methodologies. The relative importance of the array of processes that could affect Me-ENM bioavailability remains poorly known, but new approaches and models are developing rapidly. Enough is known, however, to conclude that traditional approaches to exposure assessment for metals would not be adequate to assess risks from Me-ENMs.

  4. Aquatic bioaccumulation and trophic transfer of tetrabromobisphenol-A flame retardant introduced from a typical e-waste recycling site.

    Science.gov (United States)

    Tao, Lin; Wu, Jiang-Ping; Zhi, Hui; Zhang, Ying; Ren, Zi-He; Luo, Xiao-Jun; Mai, Bi-Xian

    2016-07-01

    While the flame retardant chemical, tetrabromobisphenol-A (TBBP-A), has been frequently detected in the environment, knowledge regarding its species-specific bioaccumulation and trophic transfer is limited, especially in the highly contaminated sites. In this study, the components of an aquatic food web, including two invertebrates, two prey fish, and one predator fish, collected from a natural pond at an electronic waste (e-waste) recycling site in South China were analyzed for TBBP-A, using liquid chromatography-tandem mass spectrometry. The aquatic species had TBBP-A concentrations ranging from 350 to 1970 pg/g wet weight, with higher concentrations in the invertebrates relative to the fish species. Field-determined bioaccumulation factors of TBBP-A in the two aquatic invertebrates were nearly or greater than 5000, suggesting that TBBP-A is highly bioaccumulative in the two species. The lipid-normalized concentrations of TBBP-A in the aquatic species were negatively correlated with the trophic levels determined from stable nitrogen isotope (δ(15)N) (r = -0.82, p = 0.09), indicating that this compound experienced trophic dilution in the current food web. PMID:27234832

  5. VERIFICATION OF A TOXIC ORGANIC SUBSTANCE TRANSPORT AND BIOACCUMULATION MODEL

    Science.gov (United States)

    A field verification of the Toxic Organic Substance Transport and Bioaccumulation Model (TOXIC) was conducted using the insecticide dieldrin and the herbicides alachlor and atrazine as the test compounds. The test sites were two Iowa reservoirs. The verification procedure include...

  6. Role Models in Aquatic Occupations.

    Science.gov (United States)

    Brown, Mabel C.

    1982-01-01

    Provided for each of 12 minority group role models in aquatic occupations are job responsibilities, educational requirements, comments on a typical day at the job, salary range, and recommendations for students wishing to enter the field described. (JN)

  7. The bioconcentration and bioaccumulation factors for molybdenum in the aquatic environment from natural environmental concentrations up to the toxicity boundary

    International Nuclear Information System (INIS)

    In a regulatory context, bioaccumulation or bioconcentration factors are used for considering secondary poisoning potential and assessing risks to human health via the food chain. In this paper, literature data on the bioaccumulation of molybdenum in the aquatic organisms are reviewed and assessed for relevance and reliability. The data available in the literature were generated at exposure concentrations below those recommended in the REACH registration dossiers for molybdenum compounds i.e. PNECfreshwater 12.7 mg Mo/L. To address possible environmental concerns at regulatorily-relevant molybdenum concentrations, both a field study and a laboratory study were conducted. In the field study, whole body and organ-specific molybdenum levels were evaluated in fish (eel, stickleback, perch, carp bream, roach) held in the discharge water collector tanks of a molybdenum processing plant, containing a mean measured molybdenum level of 1.03 mg Mo/L. In the laboratory study, rainbow trout were exposed to two different nominal molybdenum levels (1.0 and 12.7 mg Mo/L), for 60 days followed by a 60-day depuration period. Whole body concentrations in rainbow trout during the exposure period were between < 0.20 and 0.53 mg Mo/L. Muscle tissue molybdenum concentrations in fish taken from both experiments remained below 0.2 mg/kg dry wt. These studies show an inverse relationship between exposure concentration and bioconcentration or bioaccumulation factor for molybdenum. In aquatic organisms, and in fish in particular, internal molybdenum concentrations are maintained in the presence of variation in external molybdenum concentrations. These observations must be considered when evaluating potential risks associated with the bioconcentration and/or bioaccumulation of molybdenum in the aquatic environment. -- Highlights: ► Addressing environmental concerns at regulatory-relevant molybdenum concentrations. ► Inverse relationship between exposure levels and BAF (BAF increases as Mo

  8. Plastic as a Carrier of POPs to Aquatic Organisms: A Model Analysis

    NARCIS (Netherlands)

    Koelmans, A.A.; Besseling, E.; Wegner, A.; Foekema, E.M.

    2013-01-01

    It has been hypothesized that persistent organic pollutants (POPs) in microplastic may pose a risk to aquatic organisms. Here we develop and analyze a conceptual model that simulates the effects of plastic on bioaccumulation of POPs. The model accounts for dilution of exposure concentration by sorpt

  9. Trait-based modelling of bioaccumulation by freshwater benthic invertebrates.

    Science.gov (United States)

    Sidney, Livia Alvarenga; Diepens, Noël J; Guo, Xiaoying; Koelmans, Albert A

    2016-07-01

    Understanding the role of species traits in chemical exposure is crucial for bioaccumulation and toxicity assessment of chemicals. We measured and modelled bioaccumulation of polychlorinated biphenyls (PCBs) in Chironomus riparius, Hyalella azteca, Lumbriculus variegatus and Sphaerium corneum. We used a battery test procedure with multiple enclosures in one aquarium, which maximized uniformity of exposure for the different species, such that the remaining variability was due mostly to species traits. The relative importance of uptake from either pore water or sediment ingestion was manipulated by using 28 d aged standard OECD sediment with low (1%) and medium (5%) OM content and 13 months aged sediment with medium OM (5%) content. Survival was ≥76% and wet weight increased for all species. Reproduction of H. azteca and weight gain of H. azteca and S. corneum were significantly higher in the medium OM aged sediments than in other sediments, perhaps due to a more developed microbial community (i.e., increase in food resources). Biota-sediment accumulation factors (BSAF) ranged from 3 to 114, depending on species and PCB congener, with C. riparius (3-10)bioaccumulation model with species-specific bioaccumulation parameters fitted well to the experimental data and showed that bioaccumulation parameters were depended on species traits. Enclosure-based battery tests and mechanistic BSAF models are expected to improve the quality of the exposure assessment in whole sediment toxicity tests. PMID:27126443

  10. Use of 65 Zn as radioactive tracer in the bioaccumulation study of zinc by aquatic organisms

    International Nuclear Information System (INIS)

    The present work has as main objective to emphasize the importance of using radioactive tracers as well as to establish a methodology for the utilization of 65 Zn in the bioaccumulation study of zinc by Poecilia reticulata. The exposure time varied from 5 days (short term experiments) to 30 days (long term experiments). The bioaccumulation of zinc from the water as well as the elimination of the metal previously absorbed were determined by measuring the activity of 65 Zn which was added to the water in the beginning of the experiments. The technique chosen is suitable to study the behaviour of the stable zinc since the radionuclide used is an isotope of the same element and therefore presents the same chemical properties. (author)

  11. Nuclear microscopy as a tool in TiO2 nanoparticles bioaccumulation studies in aquatic species

    Science.gov (United States)

    Pinheiro, Teresa; Moita, Liliana; Silva, Luís; Mendonça, Elsa; Picado, Ana

    2013-07-01

    Engineered Titanium nanoparticles are used for a wide range of applications from coatings, sunscreen cosmetic additives to solar cells or water treatment agents. Inevitably environmental exposure can be expected and data on the ecotoxicological evaluation of nanoparticles are still scarce. The potential effects of nanoparticles of titanium dioxide (TiO2) on two model organisms, the water flea, Daphnia magna and the duckweed Lemna minor, were examined in semichronic toxicity tests. Daphnia and Lemna were exposed to TiO2 nanoparticles (average particle size value of 28 ± 11 nm (n = 42); concentration range, 1.4-25 mg/L) by dietary route and growth in medium containing the nanoparticles of TiO2, respectively. Both morphology and microdistribution of Ti in the individuals were examined by nuclear microscopy techniques. A significant amount of TiO2 was found accumulated in Daphnia exposed to nanoparticles. Nuclear microscopy imaging revealed that Ti was localized only in the digestive tract of the Daphnia, which displayed difficulty in eliminating the nanoparticles from their body. Daphnia showed higher mortality when exposed to higher concentrations of TiO2 (>10 mg/L). The exposure to TiO2 nanoparticles above 25 mg/L caused morphological alterations in Lemna. The roots became stiff and fronds colorless. The Ti mapping of cross-sections of roots and fronds showed that Ti was mainly deposited in the epidermis of the fronds and roots, with minor internalization. In summary, exposure of aquatic organisms to TiO2 nanoparticles may alter the physiology of these organisms at individual and population levels, posing risks to aquatic ecosystems.

  12. Bioaccumulation and tissue distribution of a quaternary ammonium surfactant in three aquatic species

    Energy Technology Data Exchange (ETDEWEB)

    Knezovich, J.P.; Lawton, M.P.; Inouye, L.S.

    1989-01-01

    Quaternary ammonium compounds (QACs) are commonly used as surfactants in drilling muds and fabric softeners and as biocides in antiseptics and disinfectants. QACs and cationic polyelectrolytes elicit acute toxic effects in aquatic organisms by disrupting the structure and function of gill tissues, which may result in the suffocation of the organism. Little information is available, however, on the relative availability and distribution of QACs in the tissues of aquatic organisms. Information of this nature is required to understand the potential consequences of releases of sublethal concentrations of QACs into the aquatic environment. In this study, hexadecylpyridinium bromide (HPB; CAS 140-72-7) was selected as a compound for initial study because it belongs to a chemical class (alkylpyridinium QACs) that includes the most toxic and environmentally persistent QACs. Clams, minnows, and tadpoles were chosen as test organisms to define the relative availability of HPB to organisms that occupy distinctly different ecological niches.

  13. EcoCasting: Using NetLogo models of aquatic ecosystems to teach scientific inquiry

    Science.gov (United States)

    Buzby, C. K.; Jona, K.

    2010-12-01

    The EcoCasting project from the Office of STEM Education Partnerships (OSEP) at Northwestern University has developed a computer model-based curriculum for high school environmental science classes to study complexity in aquatic ecosystems. EcoCasting aims to deliver cutting edge scientific research on bioaccumulation in invaded Great Lakes food webs to high school classes. Scientists and environmental engineers at Northwestern are investigating unusual bioaccumulation patterns in invaded food webs of the Great Lakes. High school students are exploring this authentic data to understand what is causing the anomalies in the data. Students use a series of NetLogo agent-based models of an aquatic ecosystem to study how toxins accumulate in the food web. Using these models, students learn about predator-prey relationships, bioaccumulation, and invasive species. Students are confronted with contradictory data collected by scientists and investigate alternative food web mechanisms at work. By studying the individual variables, students learn common scientific principles. When multiple variables are combined in a unifying model, students learn that the interactions lead to unexpected outcomes. Students learn about the complexity of the ecosystem and gain proficiency interpreting computer models and scientific data collection in this curriculum. Model of aquatic food chain

  14. Spatial Pattern Dynamics in Aquatic Ecosystem Modelling

    NARCIS (Netherlands)

    Hong Li

    2009-01-01

    In this thesis, several modelling approaches are explored to represent spatial pattern dynamics of aquatic populations in aquatic ecosystems by the combination of models, knowledge and data in different scales. It is shown that including spatially distributed inputs retrieved from Remote Sensing i

  15. Cadmium bioaccumulation factors for terrestrial species: Application of the mechanistic bioaccumulation model OMEGA to explain field data

    Energy Technology Data Exchange (ETDEWEB)

    Veltman, Karin [Department of Environmental Science, Radboud University Nijmegen, P.O. Box 9010, Toernooiveld 1, 6500 GL Nijmegen (Netherlands)], E-mail: K.Veltman@science.ru.nl; Huijbregts, Mark A.J.; Hendriks, A. Jan [Department of Environmental Science, Radboud University Nijmegen, P.O. Box 9010, Toernooiveld 1, 6500 GL Nijmegen (Netherlands)

    2008-12-01

    In environmental risk assessment of metals it is often assumed that the biota-to-soil accumulation factor (BSAF) is generic and constant. However, previous studies have shown that cadmium bioaccumulation factors of earthworms and small mammals are inversely related to total soil concentrations. Here, we provide an overview of cadmium accumulation in terrestrial species belonging to different trophic levels, including plants, snails and moles. Internal metal concentrations of these species are less than linearly related to total soil levels, which is in accordance with previously observed trends. The mechanistic bioaccumulation model OMEGA (Optimal Modeling for Ecotoxicological Applications) is used to provide a quantitative explanation of these trends in cadmium accumulation. Our results indicate that the model accurately predicts cadmium accumulation in earthworms, voles and shrews when accounting for geochemical availability of metals and saturable uptake kinetics.

  16. Impact of polychlorinated biphenyl and polycyclic aromatic hydrocarbon sequestration in sediment on bioaccumulation in aquatic food webs

    NARCIS (Netherlands)

    Moermond, C.T.A.; Roessink, I.; Jonker, M.T.O.; Meijer, T.; Koelmans, A.A.

    2007-01-01

    It is not clear whether sequestration or aging of organic chemicals like polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) limits accumulation in higher levels of aquatic food chains. Therefore, the effect of aging on accumulation was studied in 1-m3 model ecosystems that

  17. Significance of Xenobiotic Metabolism for Bioaccumulation Kinetics of Organic Chemicals in Gammarus pulex

    OpenAIRE

    Ashauer, Roman; Hintermeister, Anita; O’Connor, Isabel; Elumelu, Maline; Hollender, Juliane; Escher, Beate I

    2012-01-01

    Bioaccumulation and biotransformation are key toxicokinetic processes that modify toxicity of chemicals and sensitivity of organisms. Bioaccumulation kinetics vary greatly among organisms and chemicals; thus, we investigated the influence of biotransformation kinetics on bioaccumulation in a model aquatic invertebrate using fifteen 14C-labeled organic xenobiotics from diverse chemical classes and physicochemical properties (1,2,3-trichlorobenzene, imidacloprid, 4,6-dinitro-o-cresol, ethylacry...

  18. Toxicokinetic modeling challenges for aquatic nanotoxicology

    Directory of Open Access Journals (Sweden)

    Wei-Yu eChen

    2016-01-01

    Full Text Available Nanotoxicity has become of increasing concern since the rapid development of metal nanoparticles (NPs. Aquatic nanotoxicity depends on crucial qualitative and quantitative properties of nanomaterials that induce adverse effects on subcellular, tissue, and organ level. The dose-response effects of size-dependent metal NPs, however, are not well investigated in aquatic organisms. In order to determine the uptake and elimination rate constants for metal NPs in the metabolically active/ detoxified pool of tissues, a one-compartmental toxicokinetic model can be applied when subcellular partitioning of metal NPs data would be available. The present review is an attempt to describe the nano-characteristics of toxicokinetics and subcellular partitioning on aquatic organisms with the help of the mechanistic modeling for NP size-dependent physiochemical properties and parameters. Physiologically-based pharmacokinetic (PBPK models can provide an effective tool to estimate the time course of NP accumulation in target organs and is useful in quantitative risk assessments. NP accumulation in fish should take into account different effects of different NP sizes to better understand tissue accumulative capacities and dynamics. The size-dependent NP partition coefficient is a crucial parameter that influences tissue accumulation levels in PBPK modeling. Further research is needed to construct the effective systems-level oriented toxicokinetic model that can provide a useful tool to develop quantitatively the robustly approximate relations that convey a better insight into the impacts of environmental metal NPs on subcellular and tissue/organ responses in aquatic organisms.

  19. Nuclear microscopy as a tool in TiO{sub 2} nanoparticles bioaccumulation studies in aquatic species

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Teresa, E-mail: murmur@itn.pt [IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa and Centro de Física Nuclear, Universidade de Lisboa (Portugal); Moita, Liliana; Silva, Luís; Mendonça, Elsa; Picado, Ana [LNEG, Laboratório Nacional de Energia e Geologia, I.P. Estrada do Paço do Lumiar 22, 1649-038 Lisboa (Portugal)

    2013-07-01

    Engineered Titanium nanoparticles are used for a wide range of applications from coatings, sunscreen cosmetic additives to solar cells or water treatment agents. Inevitably environmental exposure can be expected and data on the ecotoxicological evaluation of nanoparticles are still scarce. The potential effects of nanoparticles of titanium dioxide (TiO{sub 2}) on two model organisms, the water flea, Daphnia magna and the duckweed Lemna minor, were examined in semichronic toxicity tests. Daphnia and Lemna were exposed to TiO{sub 2} nanoparticles (average particle size value of 28 ± 11 nm (n = 42); concentration range, 1.4–25 mg/L) by dietary route and growth in medium containing the nanoparticles of TiO{sub 2}, respectively. Both morphology and microdistribution of Ti in the individuals were examined by nuclear microscopy techniques. A significant amount of TiO{sub 2} was found accumulated in Daphnia exposed to nanoparticles. Nuclear microscopy imaging revealed that Ti was localized only in the digestive tract of the Daphnia, which displayed difficulty in eliminating the nanoparticles from their body. Daphnia showed higher mortality when exposed to higher concentrations of TiO{sub 2} (>10 mg/L). The exposure to TiO{sub 2} nanoparticles above 25 mg/L caused morphological alterations in Lemna. The roots became stiff and fronds colorless. The Ti mapping of cross-sections of roots and fronds showed that Ti was mainly deposited in the epidermis of the fronds and roots, with minor internalization. In summary, exposure of aquatic organisms to TiO{sub 2} nanoparticles may alter the physiology of these organisms at individual and population levels, posing risks to aquatic ecosystems.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:26845188

  2. Effect of incorporation of uncertainty in PCB bioaccumulation factors on modeled receptor doses

    Energy Technology Data Exchange (ETDEWEB)

    Welsh, C.; Duncan, J.; Purucker, S. [Oak Ridge National Lab., TN (United States). Center for Risk Management; Richardson, N. [ABB Environmental Services, Inc., Wakefield, MA (United States); Redfearn, A. [Automated Sciences Group, Inc., Oak Ridge, TN (United States)

    1995-12-31

    Bioaccumulation factors (BAFs) are regularly employed in ecological risk assessments to model contaminant transfer through ecological food chains. The authors compiled data on bioaccumulation of PCBs in plants, invertebrates, birds, and mammals from published literature and used these data to develop regression equations relating soil or food concentrations to bioaccumulation. They then used Latin Hypercube simulation techniques and simple food chain models to incorporate uncertainty in the BAF regressions into the derivation of exposure dose estimates for selected wildlife receptors. The authors present their preliminary results in this paper. Dose estimates ranged over several orders of magnitude for herbivorous, insectivorous, and carnivorous receptors. These results suggest incorporating the uncertainty in BAF values into food chain exposure models could provide risk assessors and risk managers with information on the probability of a given outcome that can be used in interpreting the potential risks at hazardous waste sites.

  3. Environmental relevance of laboratory-derived kinetic models to predict trace metal bioaccumulation in gammarids: Field experimentation at a large spatial scale (France).

    Science.gov (United States)

    Urien, N; Lebrun, J D; Fechner, L C; Uher, E; François, A; Quéau, H; Coquery, M; Chaumot, A; Geffard, O

    2016-05-15

    Kinetic models have become established tools for describing trace metal bioaccumulation in aquatic organisms and offer a promising approach for linking water contamination to trace metal bioaccumulation in biota. Nevertheless, models are based on laboratory-derived kinetic parameters, and the question of their relevance to predict trace metal bioaccumulation in the field is poorly addressed. In the present study, we propose to assess the capacity of kinetic models to predict trace metal bioaccumulation in gammarids in the field at a wide spatial scale. The field validation consisted of measuring dissolved Cd, Cu, Ni and Pb concentrations in the water column at 141 sites in France, running the models with laboratory-derived kinetic parameters, and comparing model predictions and measurements of trace metal concentrations in gammarids caged for 7 days to the same sites. We observed that gammarids poorly accumulated Cu showing the limited relevance of that species to monitor Cu contamination. Therefore, Cu was not considered for model predictions. In contrast, gammarids significantly accumulated Pb, Cd, and Ni over a wide range of exposure concentrations. These results highlight the relevance of using gammarids for active biomonitoring to detect spatial trends of bioavailable Pb, Cd, and Ni contamination in freshwaters. The best agreements between model predictions and field measurements were observed for Cd with 71% of good estimations (i.e. field measurements were predicted within a factor of two), which highlighted the potential for kinetic models to link Cd contamination to bioaccumulation in the field. The poorest agreements were observed for Ni and Pb (39% and 48% of good estimations, respectively). However, models developed for Ni, Pb, and to a lesser extent for Cd, globally underestimated bioaccumulation in caged gammarids. These results showed that the link between trace metal concentration in water and in biota remains complex, and underlined the limits of

  4. Pharmacokinetic modeling in aquatic animals. 1. Models and concepts

    Science.gov (United States)

    Barron, M.G.; Stehly, Guy R.; Hayton, W.L.

    1990-01-01

    While clinical and toxicological applications of pharmacokinetics have continued to evolve both conceptually and experimentally, pharmacokinetics modeling in aquatic animals has not progressed accordingly. In this paper we present methods and concepts of pharmacokinetic modeling in aquatic animals using multicompartmental, clearance-based, non-compartmental and physiologically-based pharmacokinetic models. These models should be considered as alternatives to traditional approaches, which assume that the animal acts as a single homogeneous compartment based on apparent monoexponential elimination.

  5. Development of a dynamic model for estimating the food web transfer of chemicals in small aquatic ecosystems.

    Science.gov (United States)

    Nfon, Erick; Armitage, James M; Cousins, Ian T

    2011-11-15

    A dynamic combined fate and food web model was developed to estimate the food web transfer of chemicals in small aquatic ecosystems (i.e. ponds). A novel feature of the modeling approach is that aquatic macrophytes (submerged aquatic vegetation) were included in the fate model and were also a food item in the food web model. The paper aims to investigate whether macrophytes are effective at mitigating chemical exposure and to compare the modeling approach developed here with previous modeling approaches recommended in the European Union (EU) guideline for risk assessment of pesticides. The model was used to estimate bioaccumulation of three hypothetical chemicals of varying hydrophobicity in a pond food web comprising 11 species. Three different macrophyte biomass densities were simulated in the model experiments to determine the influence of macrophytes on fate and bioaccumulation. Macrophytes were shown to have a significant effect on the fate and food web transfer of highly hydrophobic compounds with log KOW>=5. Modeled peak concentrations in biota were highest for the scenarios with the lowest macrophyte biomass density. The distribution and food web transfer of the hypothetical compound with the lowest hydrophobicity (log KOW=3) was not affected by the inclusion of aquatic macrophytes in the pond environment. For the three different hypothetical chemicals and at all macrophyte biomass densities, the maximum predicted concentrations in the top predator in the food web model were at least one order of magnitude lower than the values estimated using methods suggested in EU guidelines. The EU guideline thus provides a highly conservative estimate of risk. In our opinion, and subject to further model evaluation, a realistic assessment of dynamic food web transfer and risk can be obtained using the model presented here. PMID:21962596

  6. Coupled mother-child model for bioaccumulation of POPs in nursing infants

    Energy Technology Data Exchange (ETDEWEB)

    Trapp, Stefan [Technical University of Denmark, Department of Environmental Engineering, Bygningstorvet 115, DK-2800 Kongens Lyngby (Denmark)], E-mail: stt@env.dtu.dk; Ma Bomholtz, Li [Technical University of Denmark, Department of Environmental Engineering, Bygningstorvet 115, DK-2800 Kongens Lyngby (Denmark); Legind, Charlotte N. [Technical University of Denmark, Department of Environmental Engineering, Bygningstorvet 115, DK-2800 Kongens Lyngby (Denmark); Department of Agricultural Sciences, Faculty of Life Sciences, University of Copenhagen, Hojbakkegard Alle 13, DK-2630 Taastrup (Denmark)

    2008-11-15

    Bioaccumulation of persistent organic pollutants (POPs) leads to high levels in human milk and high doses of POPs for nursing infants. This is currently not considered in chemical risk assessment. A coupled model for bioaccumulation of organic chemicals in breast-feeding mother and nursing infant was developed and tested for a series of organic compounds. The bioaccumulation factors (BAFs) in mother, breast milk and child were predicted to vary with log K{sub OW} and, for volatile compounds, with K{sub AW} and concentration in air. The concentrations of POPs in the infant body increase the first half year to about factor 3 above mother and decline thereafter to lower levels. The predicted results are close to empirical data and to an empirical regression. The new mother-child model is compact due to its easy structure and the analytical matrix solution. It could be added to existing exposure and risk assessment systems, such as EUSES. - This paper addresses a model for accumulation of organic compounds by mother and breast-fed infant, applicable for exposure assessment within larger frameworks.

  7. Exploring, exploiting and evolving diversity of aquatic ecosystem models

    DEFF Research Database (Denmark)

    Janssen, Annette B. G.; Arhonditsis, George B.; Beusen, Arthur;

    2015-01-01

    Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality...... management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity...

  8. Modeling bioaccumulation in humans using poly-parameter linear free energy relationships (PPLFERS)

    International Nuclear Information System (INIS)

    Chemical partition coefficients between environmental media and biological tissues are a key component of bioaccumulation models. The single-parameter linear free energy relationships (spLFERs) commonly used for predicting partitioning are often derived using apolar chemicals and may not accurately capture polar chemicals. In this study, a poly-parameter LFER (ppLFER) based model of organic chemical bioaccumulation in humans is presented. Chemical partitioning was described by an air-body partition coefficient that was a volume weighted average of ppLFER based partition coefficients for the major organs and tissues constituting the human body. This model was compared to a spLFER model treating the body as a mixture of lipid (∼ octanol) and water. Although model agreement was good for hydrophobic chemicals (average difference 15% for log KOW > 4 and log KOA > 8), the ppLFER model predicted ∼ 90% lower body burdens for hydrophilic chemicals (log KOW < 0). This was mainly due to lower predictions of muscle and adipose tissue sorption capacity for these chemicals. A comparison of the predicted muscle and adipose tissue sorption capacities of hydrophilic chemicals with measurements indicated that the ppLFER and spLFER models' uncertainties were similar. Consequently, little benefit from the implementation of ppLFERs in this model was identified. - Research Highlights: →Implementation of ppLFERs resulted in on average 90% lower predicted body burdens. →Uncertainties in spLFER and ppLFER predictions were similar. →The benefit from implementation of ppLFERs in bioaccumulation models was limited.

  9. Modeling bioaccumulation and biomagnification of nonylphenol and its ethoxylates in estuarine-marine food chains.

    Science.gov (United States)

    Korsman, John C; Schipper, Aafke M; de Vos, Martine G; van den Heuvel-Greve, Martine J; Vethaak, A Dick; de Voogt, Pim; Hendriks, A Jan

    2015-11-01

    There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its ethoxylates (NPEOs), but their toxico-kinetic mechanisms remain unclear. In the present investigation, we explored the accumulation of NP and NPEOs in estuarine-marine food chains with a bioaccumulation model comprising five trophic levels. Using this model, we estimated uptake and elimination rate constants for NPEOs based on the organisms' weight and lipid content and the chemicals' Kow. Further, we calculated accumulation factors for NP and NPEOs, including biota-sediment accumulation factors (BSAF) and biomagnification factors (BMF), and compared these to independent field measurements collected in the Western Scheldt estuary in The Netherlands and field data reported in the literature. The estimated BSAF values for NP and total NPEOs were below 1 for all trophic levels. The estimated BMF values were around 1 for all trophic levels except for the highest level (carnivorous mammals and birds). For this trophic level, the estimated BMF value varied between 0.1 and 2.4, depending on the biotransformation capacity. For all trophic levels, except primary producers, the accumulation estimates that accounted for biotransformation of NPEOs into NP were closer to the field data than model estimates that did not include biotransformation, indicating that NP formation by biotransformation of NPEOs might occur in organisms. PMID:26026901

  10. A method for improving predictive modeling by taking into account lag time: Example of selenium bioaccumulation in a flowing system.

    Science.gov (United States)

    Beckon, William N

    2016-07-01

    For bioaccumulative substances, efforts to predict concentrations in organisms at upper trophic levels, based on measurements of environmental exposure, have been confounded by the appreciable but hitherto unknown amount of time it may take for bioaccumulation to occur through various pathways and across several trophic transfers. The study summarized here demonstrates an objective method of estimating this lag time by testing a large array of potential lag times for selenium bioaccumulation, selecting the lag that provides the best regression between environmental exposure (concentration in ambient water) and concentration in the tissue of the target organism. Bioaccumulation lag is generally greater for organisms at higher trophic levels, reaching times of more than a year in piscivorous fish. Predictive modeling of bioaccumulation is improved appreciably by taking into account this lag. More generally, the method demonstrated here may improve the accuracy of predictive modeling in a wide variety of other cause-effect relationships in which lag time is substantial but inadequately known, in disciplines as diverse as climatology (e.g., the effect of greenhouse gases on sea levels) and economics (e.g., the effects of fiscal stimulus on employment). PMID:27149556

  11. Understanding carbon regulation in aquatic systems - Bacteriophages as a model

    OpenAIRE

    Swapnil Sanmukh; Krishna Khairnar; Waman Paunikar; Satish Lokhande

    2015-01-01

    The bacteria and their phages are the most abundant constituents of the aquatic environment, and so represent an ideal model for studying carbon regulation in an aquatic system. The microbe-mediated interconversion of bioavailable organic carbon (OC) into dissolved organic carbon (DOC) by the microbial carbon pump (MCP) has been suggested to have the potential to revolutionize our view of carbon sequestration. It is estimated that DOC is the largest pool of organic matter in the ocean and, th...

  12. A community-based framework for aquatic ecosystem models

    DEFF Research Database (Denmark)

    Trolle, Didde; Hamilton, D. P.; Hipsey, M. R.;

    2012-01-01

    Here, we communicate a point of departure in the development of aquatic ecosystem models, namely a new community-based framework, which supports an enhanced and transparent union between the collective expertise that exists in the communities of traditional ecologists and model developers. Through...... aim to (i) advance collaboration within the aquatic ecosystem modelling community, (ii) enable increased use of models for research, policy and ecosystem-based management, (iii) facilitate a collective framework using common (standardised) code to ensure that model development is incremental, (iv......) avoid 're-inventing the wheel', thus accelerating improvements to aquatic ecosystem models. We intend to achieve this as a community that fosters interactions amongst ecologists and model developers. Further, we outline scientific topics recently articulated by the scientific community, which lend...

  13. Public lakes, private lakeshore: modeling protection of native aquatic plants.

    Science.gov (United States)

    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. PMID:23609308

  14. Explaining differences between bioaccumulation measurements in laboratory and field data through use of a probabilistic modeling approach

    Science.gov (United States)

    Selck, Henriette; Drouillard, Ken; Eisenreich, Karen; Koelmans, Albert A.; Palmqvist, Annemette; Ruus, Anders; Salvito, Daniel; Schultz, Irv; Stewart, Robin; Weisbrod, Annie; van den Brink, Nico W.; van den Heuvel-Greve, Martine

    2012-01-01

    In the regulatory context, bioaccumulation assessment is often hampered by substantial data uncertainty as well as by the poorly understood differences often observed between results from laboratory and field bioaccumulation studies. Bioaccumulation is a complex, multifaceted process, which calls for accurate error analysis. Yet, attempts to quantify and compare propagation of error in bioaccumulation metrics across species and chemicals are rare. Here, we quantitatively assessed the combined influence of physicochemical, physiological, ecological, and environmental parameters known to affect bioaccumulation for 4 species and 2 chemicals, to assess whether uncertainty in these factors can explain the observed differences among laboratory and field studies. The organisms evaluated in simulations including mayfly larvae, deposit-feeding polychaetes, yellow perch, and little owl represented a range of ecological conditions and biotransformation capacity. The chemicals, pyrene and the polychlorinated biphenyl congener PCB-153, represented medium and highly hydrophobic chemicals with different susceptibilities to biotransformation. An existing state of the art probabilistic bioaccumulation model was improved by accounting for bioavailability and absorption efficiency limitations, due to the presence of black carbon in sediment, and was used for probabilistic modeling of variability and propagation of error. Results showed that at lower trophic levels (mayfly and polychaete), variability in bioaccumulation was mainly driven by sediment exposure, sediment composition and chemical partitioning to sediment components, which was in turn dominated by the influence of black carbon. At higher trophic levels (yellow perch and the little owl), food web structure (i.e., diet composition and abundance) and chemical concentration in the diet became more important particularly for the most persistent compound, PCB-153. These results suggest that variation in bioaccumulation

  15. Modeling bioaccumulation and biomagnification of nonylphenol and its ethoxylates in estuarine-marine food chains

    NARCIS (Netherlands)

    Korsman, J.C.; Schipper, A.M.; Vos, de M.G.; Heuvel-Greve, van den M.J.; Vethaak, A.D.; Voogt, de Pim; Hendriks, A.J.

    2015-01-01

    There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its ethoxylates (NPEOs), but their toxico-kinetic mechanisms remain unclear. In the present investigation, we explored the accumulation of NP and NPEOs in estuarine-marine food chains with a bioaccumulation

  16. Modeling bioaccumulation and biomagnification of nonylphenol and its ethoxylates in estuarine-marine food chains

    NARCIS (Netherlands)

    J.C. Korsman; A.M. Schipper; M.G. de Vos; M.J. van den Heuvel-Greve; A.D. Vethaak; P. de Voogt; A.J. Hendriks

    2015-01-01

    There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its ethoxylates (NPEOs), but their toxico-kinetic mechanisms remain unclear. In the present investigation, we explored the accumulation of NP and NPEOs in estuarine-marine food chains with a bioaccumulation mod

  17. Biosorption of Strontium from Simulated Nuclear Wastewater by Scenedesmus spinosus under Culture Conditions: Adsorption and Bioaccumulation Processes and Models

    Directory of Open Access Journals (Sweden)

    Mingxue Liu

    2014-06-01

    Full Text Available Algae biosorption is an ideal wastewater treatment method when coupled with algae growth and biosorption. The adsorption and bioaccumulation of strontium from simulated nuclear wastewater by Scenedesmus spinosus were investigated in this research. One hundred mL of cultured S. spinosus cells with a dry weight of 1.0 mg in simulated nuclear wastewater were used to analyze the effects on S. spinosus cell growth as well as the adsorption and bioaccumulation characters under conditions of 25 ± 1 °C with approximately 3,000 lux illumination. The results showed that S. spinosus had a highly selective biosorption capacity for strontium, with a maximum bioremoval ratio of 76%. The adsorbed strontium ion on cell walls was approximately 90% of the total adsorbed amount; the bioaccumulation in the cytoplasm varied by approximately10%. The adsorption quantity could be described with an equilibrium isotherm. The pseudo-second-order kinetic model suggested that adsorption was the rate-limiting step of the biosorption process. A new bioaccumulation model with three parameters was proposed and could give a good fit with the experiment data. The results suggested that S. spinosus may be a potential biosorbent for the treatment of nuclear wastewater in culture conditions.

  18. Aquatic pathways model to predict the fate of phenolic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Aaberg, R.L.; Peloquin, R.A.; Strenge, D.L.; Mellinger, P.J.

    1983-04-01

    Organic materials released from energy-related activities could affect human health and the environment. To better assess possible impacts, we developed a model to predict the fate of spills or discharges of pollutants into flowing or static bodies of fresh water. A computer code, Aquatic Pathways Model (APM), was written to implement the model. The computer programs use compartmental analysis to simulate aquatic ecosystems. The APM estimates the concentrations of chemicals in fish tissue, water and sediment, and is therefore useful for assessing exposure to humans through aquatic pathways. The APM will consider any aquatic pathway for which the user has transport data. Additionally, APM will estimate transport rates from physical and chemical properties of chemicals between several key compartments. The major pathways considered are biodegradation, fish and sediment uptake, photolysis, and evaporation. The model has been implemented with parameters for distribution of phenols, an important class of compounds found in the water-soluble fractions of coal liquids. Current modeling efforts show that, in comparison with many pesticides and polyaromatic hydrocarbons (PAH), the lighter phenolics (the cresols) are not persistent in the environment. The properties of heavier molecular weight phenolics (indanols, naphthols) are not well enough understood at this time to make similar judgements. For the twelve phenolics studied, biodegradation appears to be the major pathway for elimination from aquatic environments. A pond system simulation (using APM) of a spill of solvent refined coal (SRC-II) materials indicates that phenol, cresols, and other single cyclic phenolics are degraded to 16 to 25 percent of their original concentrations within 30 hours. Adsorption of these compounds into sediments and accumulation by fish was minor.

  19. Bioaccumulation and trophic dilution of human pharmaceuticals across trophic positions of an effluent-dependent wadeable stream

    OpenAIRE

    Du, Bowen; Haddad, Samuel P.; Luek, Andreas; Scott, W. Casan; Saari, Gavin N.; Kristofco, Lauren A.; Connors, Kristin A.; Rash, Christopher; Rasmussen, Joseph B.; Chambliss, C. Kevin; Brooks, Bryan W.

    2014-01-01

    Though pharmaceuticals are increasingly observed in a variety of organisms from coastal and inland aquatic systems, trophic transfer of pharmaceuticals in aquatic food webs have not been reported. In this study, bioaccumulation of select pharmaceuticals was investigated in a lower order effluent-dependent stream in central Texas, USA, using isotope dilution liquid chromatography–tandem mass spectrometry (MS). A fish plasma model, initially developed from laboratory studies, was tested to exam...

  20. Assessment of Mercury Bioaccumulation in Zebra Cichlid (Cichlasoma Nigrofasciatum Exposed to Sublethal Concentrations of Permethrin

    Directory of Open Access Journals (Sweden)

    Mahdi Banaee

    2014-12-01

    Full Text Available Background: Aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. Mercury is a toxic metal with no known biological benefit to organisms. Bioavailability of mercury in aquatic environments depends on biological and non-biological parameters including other pollutants. Therefore, the objectives of this research were to determine the effects of permethrin on bioaccumulation of mercury in zebra cichlid. Methods: Acute toxicity (LC50 of permethrin and mercury chloride was evaluated by estimating mortality in Probit Model in SPSS (version 19.0 IBM. In sub-lethal toxicity, zebra cichlid (Cichlasoma nigrofasciatum was exposed to various concentrations of permethrin (0.0, 0.40, 0.80, 1.20 and 1.60 µg.L-1 combined with 20 µg.L-1 mercury chloride for 15 days. At the end of the experiment, mercury concentrations were measured using ICP-OES-Perkin elmer (optima 7300-DV. Results: 96 h LC50 values of permethrin and mercury for C. nigrofasciatum were calculated to be 17.55 µg.L-1 and 140.38 µg.L-1, respectively. Our results clearly showed that the bioaccumulation of mercury in the specimens increased with increasing concentrations of permethrin to 1.20 and 1.60 µg.L-1. Conclusion: Increasing the concentration of permethrin had synergistic effects on the bioaccumulation of mercury in fish.

  1. Understanding carbon regulation in aquatic systems - Bacteriophages as a model.

    Science.gov (United States)

    Sanmukh, Swapnil; Khairnar, Krishna; Paunikar, Waman; Lokhande, Satish

    2015-01-01

    The bacteria and their phages are the most abundant constituents of the aquatic environment, and so represent an ideal model for studying carbon regulation in an aquatic system. The microbe-mediated interconversion of bioavailable organic carbon (OC) into dissolved organic carbon (DOC) by the microbial carbon pump (MCP) has been suggested to have the potential to revolutionize our view of carbon sequestration. It is estimated that DOC is the largest pool of organic matter in the ocean and, though a major component of the global carbon cycle, its source is not yet well understood. A key element of the carbon cycle is the microbial conversion of DOC into inedible forms. The primary aim of this study is to understand the phage conversion from organic to inorganic carbon during phage-host interactions. Time studies of phage-host interactions under controlled conditions reveal their impact on the total carbon content of the samples and their interconversion of organic and inorganic carbon compared to control samples. A total organic carbon (TOC) analysis showed an increase in inorganic carbon content by 15-25 percent in samples with bacteria and phage compared to samples with bacteria alone. Compared to control samples, the increase in inorganic carbon content was 60-70-fold in samples with bacteria and phage, and 50-55-fold for samples with bacteria alone. This study indicates the potential impact of phages in regulating the carbon cycle of aquatic systems. PMID:26213615

  2. Mercury methylation, export and bioaccumulation in rice agriculture - model results from comparative and experimental studies in 3 regions of the California Delta, USA

    Science.gov (United States)

    Windham-Myers, L.; Fleck, J.; Eagles-Smith, C.; Ackerman, J.

    2013-12-01

    Seasonally flooded wetland ecosystems are often poised for mercury (Hg) methylation, thus becoming sources of methylmercury (MeHg) to in situ and downstream biota. The seasonal flooding associated with cultivation of rice (Oryza sativa) also generates MeHg, which may be stored in sediment or plants, bioaccumulated into fauna, degraded or exported, depending on hydrologic and seasonal conditions. While many U.S. waters are regulated for total Hg concentrations based on fish targets, California's Sacramento-San Joaquin Delta (Delta) will soon implement the first MeHg total maximum daily load (TMDL) control program. Since 2007, a conceptual model (DRERIP-MCM) and several ecosystem-level studies have been advanced to better understand the mechanisms behind Hg methylation, export and bioaccumulation within Delta wetlands, including rice agriculture. Three Delta rice-growing regions (Yolo Bypass, Cosumnes River, Central Delta) of varied soil characteristics, mining influences and hydrology, were monitored over full crop years to evaluate annual MeHg dynamics. In addition to fish tissue Hg accumulation, a broad suite of biogeochemical and hydrologic indices were assessed and compared between wetland types, seasons, and regions. In general, Delta rice fields were found to export MeHg during the post-harvest winter season, and promote MeHg uptake in fish and rice grain during the summer growing season. As described in a companion presentation (Eagles-Smith et al., this session), the experimental Cosumnes River study suggests that rice-derived dissolved organic carbon (DOC) fuels MeHg production and uptake into aquatic foodwebs. Explicit DRERIP-MCM linkages for the role of rice-DOC in MeHg production, export and bioaccumulation were verified across two summers (2011, 2012): rice biomass and root productivity influenced porewater DOC availability and microbial processes, which drove sediment MeHg production and flux to surface water, promoting MeHg bioaccumulation in fish

  3. Bioaccumulation Studies Associated with the Kingston Fly Ash Spill, Spring 2009 - Fall 2010

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Marshall [ORNL; Brandt, Craig C [ORNL; Fortner, Allison M [ORNL

    2012-05-01

    In December 2008, an ash dike at the Tennessee Valley Authority (TVA) Kingston Fossil Plant ruptured, releasing over one billion gallons of coal fly ash into the Emory and Clinch Rivers. Coal fly ash may contain several contaminants of concern, but of these selenium (Se) and arsenic (As) have been highlighted because of their toxicity and tendency to bioaccumulate in aquatic food chains. To assess the potential impact of the spilled fly ash on humans and the environment, a comprehensive biological and environmental monitoring program was established, for which resident aquatic organisms (among other sample media) are collected to determine contaminant exposure and evaluate the risk to humans and wildlife. Studies on bioaccumulation and fish health are major components of the TVA Biological Monitoring Program for the Kingston fly ash project. These studies were initiated in early Spring 2009 for the purposes of: (1) documenting the levels of fly ash-associated metals in various tissues of representative sentinel fish species in the area of the fly ash spill, (2) determining if exposure to fly ash-associated metals causes short, intermediate, or long-term health effects on these sentinel fish species, (3) assessing if there are causal relationships between exposure (to metals) and effects on fish, (4) evaluating, along with information regarding other ecological and physicochemical studies, the nature and route of contaminant transfer though food chains into higher level consumers, (5) providing important information for the Ecological Risk Assessment (ERA) for the Kingston fly ash project, and (6) serving as an important technology transfer or model study focused on how to best evaluate the environmental effects of fly ash, not only at the Kingston site, but also at sites on other aquatic systems where coal-fired generating stations are located. This report summarizes the bioaccumulation results from the first two years of study after the fly ash spill, including

  4. Explaining Differences Between Bioaccumulation Measurements in Laboratory and Field Data Through Use of a Probabilistic Modeling Approach

    DEFF Research Database (Denmark)

    Selck, Henriette; Drouillard, Ken; Eisenreich, Karen;

    2012-01-01

    bioaccumulation for 4 species and 2 chemicals, to assess whether uncertainty in these factors can explain the observed differences among laboratory and field studies. The organisms evaluated in simulations including mayfly larvae, deposit-feeding polychaetes, yellow perch, and little owl represented a range...... was improved by accounting for bioavailability and absorption efficiency limitations, due to the presence of black carbon in sediment, and was used for probabilistic modeling of variability and propagation of error. Results showed that at lower trophic levels (mayfly and polychaete), variability...

  5. Modelling trace metal (Hg and Pb) bioaccumulation in the Mediterranean mussel, Mytilus galloprovincialis , applied to environmental monitoring

    Science.gov (United States)

    Casas, Stellio; Bacher, Cédric

    2006-08-01

    Bioaccumulation of metal within an organism results from interactions between physiological factors (growth, weight loss, absorption and accumulation), chemical factors (metal concentration, speciation and bioavailability) and environmental factors (temperature and food concentration). To account for such interactions in the mussel Mytilus galloprovincialis, we combined bioaccumulation and Dynamic Energy Budget models. Field experiments were conducted to measure uptake and elimination kinetics for two metals (Hg and Pb) in three Mediterranean sites with differences in contamination levels, and to calibrate the models. Metal uptake from water and from food was considered separately. Metal elimination resulted from reproduction and/or from direct excretion. Contributions of physiological variables, such as body size and tissue composition, were quantified. By combining environmental and biological data, the model provided an efficient bio-monitoring tool which can be applied to various coastal environments. An application to the French bio-integrator network (RINBIO) was carried out through inverse analysis and enabled us to assess the real level of contamination in water on the basis of contamination measured in mussels.

  6. Bioaccumulation factors for radionuclides in freshwater biota

    International Nuclear Information System (INIS)

    This report analyzes over 200 carefully selected papers to provide concise data sets and methodology for estimation of bioaccumulation factors for tritium and isotopes of strontium, cesium, iodine, manganese, and cobalt in major biotic components of freshwater environments. Bioaccumulation factors of different tissues are distinguished where significant differences occur. Since conditions in the laboratory are often unnatural in terms of chemical and ecological relationships, this review was restricted as far as possible to bioaccumulation factors determined for natural systems. Because bioaccumulation factors were not available for some shorter-lived radionuclides, a methodology for converting bioaccumulation factors of stable isotopes to those of shorter-lived radionuclides was derived and utilized. The bioaccumulation factor for a radionuclide in a given organism or tissue may exhibit wide variations among bodies of water that are related to differences in ambient concentrations of stable-element and carrier-element analogues. To account for these variations, simple models are presented that relate bioaccumulation factors to stable-element and carrier-element concentrations in water. The effects of physicochemical form and other factors in causing deviations from these models are discussed. Bioaccumulation factor data are examined in the context of these models, and bioaccumulation factor relations for the selected radionuclides are presented

  7. Bioaccumulation of cadmium in an experimental aquatic food chain involving phytoplankton (Chlorella vulgaris), zooplankton (Moina macrocopa), and the predatory catfish Clarias macrocephalus x C. gariepinus

    Energy Technology Data Exchange (ETDEWEB)

    Ruangsomboon, Suneerat [Faculty of Agricultural Technology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Road, Bangkok 10520 (Thailand)]. E-mail: krsuneer@kmitl.ac.th; Wongrat, Ladda [Faculty of Fishery, Kasetsart University, Bangkok 10900 (Thailand)

    2006-06-10

    The accumulation of cadmium (Cd) was studied in an experimental aquatic food chain involving the phytoplankton Chlorella vulgaris as the primary producer, the zooplankton Moina macrocopa as the primary consumer, and the catfish Clarias macrocephalus x Clarias gariepinus as the secondary consumer. C. vulgaris was first exposed to Cd solutions at 0.00, 0.35, and 3.50 mg l{sup -1}, referred to as control group and experimental groups 1 and 2, respectively. Subsequently, each group was fed to three corresponding groups of M. macrocopa. Finally, three groups of catfish were fed these corresponding groups of M. macrocopa. After C. vulgaris was exposed to 3.50 mg l{sup -1} Cd (experimental group 2), the residual Cd in solution was only 4.01 {mu}g l{sup -1}, lower than the maximum allowable limit of Cd in natural water sources (5 {mu}g l{sup -1}). Cd concentrations in C. vulgaris were 0.01 {+-} 0.00 {mu}g g{sup -1} (dry wt) in the control group, 194 {+-} 1.80 {mu}g g{sup -1} (dry wt) in experimental group 1, and 1140 {+-} 20.06 {mu}g g{sup -1} (dry wt) in experimental group 2. The Cd concentrations in M. macrocopa were 0.01 {+-} 0.00 {mu}g g{sup -1} (dry wt) in the control group, 16.48 {+-} 2.23 {mu}g g{sup -1} (dry wt) in experimental group 1, and 56.6 {+-} 3.23 {mu}g g{sup -1} (dry wt) in experimental group 2. The Cd concentrations in catfish muscle increased with increasing Cd concentrations in the food. After 60 days of fish culture, the mean concentrations of Cd in fish muscle were 0.01 {+-} 0.00 {mu}g g{sup -1} (dry wt) in the control group, 0.61 {+-} 0.02 {mu}g g{sup -1} (dry wt) in experimental group 1 and 1.04 {+-} 0.06 {mu}g g{sup -1} (dry wt) in experimental group 2. Cd concentration in fish muscle of experimental group 2 was equal to the permissible limit. Cd accumulation affected fish growth: at the end of the study, the mean fresh weight (12.81 g) of catfish in the control group, was significantly higher than those experimental group 1 (10.43 g) and

  8. Bioaccumulation of cadmium in an experimental aquatic food chain involving phytoplankton (Chlorella vulgaris), zooplankton (Moina macrocopa), and the predatory catfish Clarias macrocephalus x C. gariepinus

    International Nuclear Information System (INIS)

    The accumulation of cadmium (Cd) was studied in an experimental aquatic food chain involving the phytoplankton Chlorella vulgaris as the primary producer, the zooplankton Moina macrocopa as the primary consumer, and the catfish Clarias macrocephalus x Clarias gariepinus as the secondary consumer. C. vulgaris was first exposed to Cd solutions at 0.00, 0.35, and 3.50 mg l-1, referred to as control group and experimental groups 1 and 2, respectively. Subsequently, each group was fed to three corresponding groups of M. macrocopa. Finally, three groups of catfish were fed these corresponding groups of M. macrocopa. After C. vulgaris was exposed to 3.50 mg l-1 Cd (experimental group 2), the residual Cd in solution was only 4.01 μg l-1, lower than the maximum allowable limit of Cd in natural water sources (5 μg l-1). Cd concentrations in C. vulgaris were 0.01 ± 0.00 μg g-1 (dry wt) in the control group, 194 ± 1.80 μg g-1 (dry wt) in experimental group 1, and 1140 ± 20.06 μg g-1 (dry wt) in experimental group 2. The Cd concentrations in M. macrocopa were 0.01 ± 0.00 μg g-1 (dry wt) in the control group, 16.48 ± 2.23 μg g-1 (dry wt) in experimental group 1, and 56.6 ± 3.23 μg g-1 (dry wt) in experimental group 2. The Cd concentrations in catfish muscle increased with increasing Cd concentrations in the food. After 60 days of fish culture, the mean concentrations of Cd in fish muscle were 0.01 ± 0.00 μg g-1 (dry wt) in the control group, 0.61 ± 0.02 μg g-1 (dry wt) in experimental group 1 and 1.04 ± 0.06 μg g-1 (dry wt) in experimental group 2. Cd concentration in fish muscle of experimental group 2 was equal to the permissible limit. Cd accumulation affected fish growth: at the end of the study, the mean fresh weight (12.81 g) of catfish in the control group, was significantly higher than those experimental group 1 (10.43 g) and experimental group 2 (10.00 g). The results showed that the measurement of Cd concentration in water does not necessarily give

  9. Recent trends in the development of ecological models applied on aquatic ecosystems.

    Science.gov (United States)

    Jørgensen, S E

    2002-02-12

    This paper presents an overview of the application of models on aquatic ecosystems. More than 17% of the models published in the focal journal in the field, Ecological Modelling, are aquatic ecosystem models. An increasing number of papers are dealing with the theoretical aspects of modeling--new modeling approaches and techniques, how models can be used to reveal ecosystem properties, and how models can better reflect the properties of ecosystems. This development implies that today we have more types of models. The characteristics, the advantages, and the disadvantages of these model types are presented briefly. The selection criteria for the presented model types are discussed, and the application of these types to models for aquatic ecosystems is reviewed. A recent improvement in model calibration of particular interest for aquatic ecosystems is presented, and the perspectives resulting from this new calibration procedure and from possible hybrids of the presented model types are discussed. PMID:12806024

  10. Recent Trends in the Development of Ecological Models Applied on Aquatic Ecosystems

    Directory of Open Access Journals (Sweden)

    S.E. Jorgensen

    2002-01-01

    Full Text Available This paper presents an overview of the application of models on aquatic ecosystems. More than 17% of the models published in the focal journal in the field, Ecological Modelling, are aquatic ecosystem models. An increasing number of papers are dealing with the theoretical aspects of modeling – new modeling approaches and techniques, how models can be used to reveal ecosystem properties, and how models can better reflect the properties of ecosystems. This development implies that today we have more types of models. The characteristics, the advantages, and the disadvantages of these model types are presented briefly. The selection criteria for the presented model types are discussed, and the application of these types to models for aquatic ecosystems is reviewed. A recent improvement in model calibration of particular interest for aquatic ecosystems is presented, and the perspectives resulting from this new calibration procedure and from possible hybrids of the presented model types are discussed.

  11. Remote Sensing and Modeling for Improving Operational Aquatic Plant Management

    Science.gov (United States)

    Bubenheim, Dave

    2016-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California’s water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, water quality changes, and expansion of invasive aquatic plants threatens ecosystems, impedes ecosystem restoration, and is economically, environmentally, and sociologically detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California and local governments to develop science-based, adaptive-management strategies for the Sacramento-San Joaquin Delta. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and waterway managers make science-informed decisions regarding management and outcomes. The team provides a comprehensive understanding of agricultural and urban land use in the Delta and the major water sheds (San Joaquin/Sacramento) supplying the Delta and interaction with drought and climate impacts on the environment, water quality, and weed growth. The team recommends conservation and modified land-use practices and aids local Delta stakeholders in developing management strategies. New remote sensing tools have been developed to enhance ability to assess conditions, inform decision support tools, and monitor management practices. Science gaps in understanding how native and invasive plants respond to altered environmental conditions are being filled and provide critical biological response parameters for Delta-SWAT simulation modeling. Operational agencies such as the California Department of Boating and Waterways provide testing and act as initial adopter of decision support tools. Methods developed by the project can become routine land and water management tools in complex river delta systems.

  12. Next generation framework for aquatic modeling of the Earth System

    Directory of Open Access Journals (Sweden)

    C. J. Vörösmarty

    2009-03-01

    Full Text Available Earth System model development is becoming an increasingly complex task. As scientists attempt to represent the physical and bio-geochemical processes and various feedback mechanisms in unprecedented detail, the models themselves are becoming increasingly complex. At the same time, the complexity of the surrounding IT infrastructure is growing as well. Earth System models must manage a vast amount of data in heterogeneous computing environments. Numerous development efforts are on the way to ease that burden and offer model development platforms that reduce IT challenges and allow scientists to focus on their science. While these new modeling frameworks (e.g. FMS, ESMF, CCA, OpenMI do provide solutions to many IT challenges (performing input/output, managing space and time, establishing model coupling, etc., they are still considerably complex and often have steep learning curves.

    The Next generation Framework for Aquatic Modeling of the Earth System (NextFrAMES, a revised version of FrAMES have numerous similarities to those developed by other teams, but represents a novel model development paradigm. NextFrAMES is built around a modeling XML that lets modelers to express the overall model structure and provides an API for dynamically linked plugins to represent the processes. The model XML is executed by the NextFrAMES run-time engine that parses the model definition, loads the module plugins, performs the model I/O and executes the model calculations. NextFrAMES has a minimalistic view representing spatial domains and treats every domain (regardless of its layout such as grid, network tree, individual points, polygons, etc. as vector of objects. NextFrAMES performs computations on multiple domains and interactions between different spatial domains are carried out through couplers. NextFrAMES allows processes to operate at different frequencies by providing rudimentary aggregation and disaggregation facilities.

    NextFrAMES was

  13. On the well posedness and further regularity of a diffusive three species aquatic model

    KAUST Repository

    Parshad, R.D.

    2012-01-01

    We consider Upadhay\\'s three species aquatic food chain model, with the inclusion of spatial spread. This is a well established food chain model for the interaction of three given aquatic species. It exhibits rich dynamical behavior, including chaos. We prove the existence of a global weak solution to the diffusive system, followed by existence of local mild and strong solution.

  14. Modelling 2,4-dichlorophenol bioavailability and bioaccumulation by the freshwater fingernail clam Sphaerium corneum using artificial particles and humic acids

    International Nuclear Information System (INIS)

    The complex and variable composition of natural sediments makes it very difficult to predict the bioavailability and bioaccumulation of sediment-bound contaminants. Several approaches have been proposed to overcome this problem, including an experimental model using artificial particles with or without humic acids as a source of organic matter. For this work, we have applied this experimental model, and also a sample of a natural sediment, to investigate the uptake and bioaccumulation of 2,4-dichlorophenol (2,4-DCP) by Sphaerium corneum. Additionally, the particle-water partition coefficients (K d) were calculated. The results showed that the bioaccumulation of 2,4-DCP by clams did not depend solely on the levels of chemical dissolved, but also on the amount sorbed onto the particles and the characteristics and the strength of that binding. This study confirms the value of using artificial particles as a suitable experimental model for assessing the fate of sediment-bound contaminants. - An experimental model is proposed to better understand the bioavailability and bioaccumulation of sediment-bound 2,4-dichlorophenol

  15. Biotic ligand modeling approach: Synthesis of the effect of major cations on the toxicity of metals to soil and aquatic organisms.

    Science.gov (United States)

    Ardestani, Masoud M; van Straalen, Nico M; van Gestel, Cornelis A M

    2015-10-01

    The biotic ligand model (BLM) approach is used to assess metal toxicity, taking into account the competition of other cations with the free metal ions for binding to the biotic ligand sites of aquatic and soil organisms. The bioavailable fraction of metals, represented by the free metal ion, is a better measure than the total concentration for assessing their potential risk to the environment. Because BLMs are relating toxicity to the fraction of biotic ligands occupied by the metal, they can be useful for investigating factors affecting metal bioaccumulation and toxicity. In the present review, the effects of major cations on the toxicity of metals to soil and aquatic organisms were comprehensively studied by performing a meta-analysis of BLM literature data. Interactions at the binding sites were shown to be species- and metal-specific. The main factors affecting the relationships between toxicity and conditional binding constants for metal binding at the biotic ligand appeared to be Ca(2+) , Mg(2+) , and protons. Other important characteristics of the exposure medium, such as levels of dissolved organic carbon and concentrations of other cations, should also be considered to obtain a proper assessment of metal toxicity to soil and aquatic organisms.

  16. Modeling (137)Cs bioaccumulation in the salmon-resident killer whale food web of the Northeastern Pacific following the Fukushima Nuclear Accident.

    Science.gov (United States)

    Alava, Juan José; Gobas, Frank A P C

    2016-02-15

    To track the long term bioaccumulation of (137)Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for (137)Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that (137)Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of (137)Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. (137)Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the (137)Cs activity in species of the food web, based on current measurements and forecasts of (137)Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term (137)Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current (137)Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term (137)Cs activities and may be good sentinels for monitoring (137)Cs in the region. Assessment of the long term consequences of (137)Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution.

  17. Modeling (137)Cs bioaccumulation in the salmon-resident killer whale food web of the Northeastern Pacific following the Fukushima Nuclear Accident.

    Science.gov (United States)

    Alava, Juan José; Gobas, Frank A P C

    2016-02-15

    To track the long term bioaccumulation of (137)Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for (137)Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that (137)Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of (137)Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. (137)Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the (137)Cs activity in species of the food web, based on current measurements and forecasts of (137)Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term (137)Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current (137)Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term (137)Cs activities and may be good sentinels for monitoring (137)Cs in the region. Assessment of the long term consequences of (137)Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution. PMID:26657356

  18. Kinetic modelling of cadmium and lead removal by aquatic mosses

    Directory of Open Access Journals (Sweden)

    R. J. E. Martins

    2014-03-01

    Full Text Available Because biosorption is a low cost and effective method for treating metal-bearing wastewaters, understanding the process kinetics is relevant for design purposes. In the present study, the performance of the aquatic moss Fontinalis antipyretica for removing cadmium and lead from simulated wastewaters has been evaluated. Five kinetic models (first-order, pseudo-first-order, Elovich, modified Ritchie second-order and pseudo-second-order were fitted to the experimental data and compared. Previously, the effect of parameters such as the initial solution pH, contact time, and initial metal ion concentration on biosorption was investigated. The initial pH of the solution was found to have an optimum value in the range of 4.0-6.0. The equilibrium sorption capacity of cadmium and lead by Fontinalis antipyretica increased with the initial metal concentration. For an initial metal concentration of 10 mg L-1, the uptake capacity of the moss, at equilibrium, is the same for both metals (4.8 mg g-1. Nevertheless, when the initial concentration increases up to 100 mg L-1, the uptake of Pb(II was higher than 78%. The pseudo-second order biosorption kinetics provided the better correlation with the experimental data (R² ≥ 0.999.

  19. Exploring the effects of temperature and resource limitation on mercury bioaccumulation in Fundulus heteroclitus using dynamic energy budget modeling

    Science.gov (United States)

    Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we conducted growth and bioaccumulation studies that contribute t...

  20. Physiologically-based pharmacokinetic modelling of distribution, bioaccumulation and excretion of POPs in Greenland sledge dogs (Canis familiaris).

    Science.gov (United States)

    Sonne, Christian; Gustavson, Kim; Letcher, Robert J; Dietz, Rune

    2015-10-01

    We used PBPK (physiologically-based pharmacokinetic) modelling to investigate distribution, bioaccumulation and excretion of the seven POPs (persistent organic pollutants) CB-99, CB-153, HCB, oxychlordane, p,p'-DDE, BDE-47 and BDE-99 in 4 adult captive Greenland sledge dog (Canis familiaris) bitches fed minke whale (Balaenoptera acuterostrata) blubber for 500-635 days. The PBPK modelled POP concentrations in adipose tissue, liver, kidney and plasma were mostly within a factor 2 of actual measured tissue levels even for those at the lower concentration end. The excretion route for oxychlordane and CB-153 was modelled to be via faeces while lung alveolar excretion dominated for BDE-47, BDE-99, HCB, p,p'-DDE and CB-99. Furthermore the model suggested the retained mass of POPs after 500 and 635 days of exposure, respectively, to be relatively low despite these POPs being highly recalcitrant. The retention increased in the following order (% of total intake); p,p'-DDE (1%)tool in risk assessment of POPs in arctic mammals. PMID:26210746

  1. Toxicity and bioaccumulation of copper in Limnodrilus hoffmeisteri under different pH values: Impacts of perfluorooctane sulfonate.

    Science.gov (United States)

    Meng, Lingjun; Yang, Shaogui; Feng, Mingbao; Qu, Ruijuan; Li, Yong; Liu, Jiaoqin; Wang, Zunyao; Sun, Cheng

    2016-03-15

    Aquatic oligochaete Limnodrilus hoffmeisteri (L. hoffmeisteri) has been commonly used as a lethal and/or sub-lethal toxicological model organism in ecological risk assessments in contaminated water environments. In this study, experiments were conducted to investigate the potential toxic effects of copper (Cu(II)) with or without perfluorooctane sulfonate (PFOS) under different pH values (6.0, 7.0 and 8.0) on LC50, bioaccumulation, and oxidative stress biomarkers in L. hoffmeisteri after 3 and 7 days. The LC50 values of Cu(II) decreased with the increasing pH and the addition of PFOS. After each exposure, increasing bioaccumulation of Cu(II) in L. hoffmeisteri was observed in the combined exposure treatments, whereas the bioaccumulation of PFOS decreased. Moreover, the activity of superoxide dismutase, the level of glutathione, and the content of malondialdehyde were significantly altered after these exposures, possibly indicating that the bioaccumulation of Cu(II) and PFOS caused adverse effects on antioxidant defenses of L. hoffmeisteri. The integrated biomarker response index, indicates that the combined effect was proposed as synergism, which is coincided with the results of toxic unit. Moreover, this work showed that aquatic environment may become more livable when water conditions changed from acidic to near-neutral or alkaline.

  2. Bioaccumulation of arsenic and silver by the caddisfly larvae Hydropsyche siltalai and H. pellucidula: A biodynamic modeling approach

    Energy Technology Data Exchange (ETDEWEB)

    Awrahman, Zmnako A., E-mail: zmnako.awrahman@uj.edu.pl [Institute of Environmental Science, Jagiellonian University, Krakow 30-348 (Poland); Rainbow, Philip S.; Smith, Brian D. [Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Khan, Farhan R. [Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Department of Environmental, Social and Spatial Change (ENSPAC), Roskilde University, Universitetsvej 1, PO Box 260, Roskilde DK-4000 (Denmark); Bury, Nicolas R. [Nutritional Sciences Division, King’s College London, Franklin–Wilkins Building, 150 Stamford Street, London SE1 9NH (United Kingdom); Fialkowski, Wojciech [Institute of Environmental Science, Jagiellonian University, Krakow 30-348 (Poland)

    2015-04-15

    Highlights: • Biodynamic models were used to predict steady state As and Ag concentrations. • Uptake and efflux rate constants for As and Ag were measured in caddisfly species. • Dietborne As was the predominant exposure route in two caddisfly species. • Diet was the only exposure route of bioaccumulated Ag in the investigated caddisflies. - Abstract: Biodynamic modeling was used to investigate the uptake and bioaccumulation of arsenic and silver from water and food by two Hydropsychid caddisfly larvae: Hydropsyche siltalai and Hydropsyche pellucidula. Radiotracer techniques determined the uptake rate constants of arsenic and silver from water, and assimilation efficiencies from food, and their subsequent loss rate constants after accumulation from either route. The uptake rate constants (±SE) of As and Ag from solution were 0.021 ± 0.005 and 0.350 ± 0.049 L g{sup −1} day{sup −1}, respectively, for H. siltalai, and 0.435 ± 0.054 and 0.277 ± 0.021 L g{sup −1} day{sup −1}, respectively, for H. pellucidula in moderately hard synthetic water at 10 °C. The assimilation efficiencies (±SE) of As and Ag from radiolabeled ingested food were 46.0 ± 7.7% and 75.7 ± 3.6%, respectively, for H. siltalai, and 61.0 ± 4.2% and 52.6 ± 8.6%, respectively, for H. pellucidula. Ag, but not As, AEs were significantly different between species. The AE of Ag differed from the AE of As in H. siltalai, but not in H. pellucidula. Mean efflux rate constants after accumulation of metals from solution or food ranged from 0.039 to 0.190 day{sup −1}. The efflux rate constants of As and Ag accumulated from solution were significantly lower than those of As and Ag assimilated from ingested food in both species. Experimentally derived k{sub u} and k{sub e} values were then used to predict As and Ag tissue concentrations in hydropsychids collected from 13 UK sites, including metal-contaminated streams in Cornwall. Arsenic and silver concentrations in environmental water

  3. Bioaccumulation of arsenic and silver by the caddisfly larvae Hydropsyche siltalai and H. pellucidula: A biodynamic modeling approach

    International Nuclear Information System (INIS)

    Highlights: • Biodynamic models were used to predict steady state As and Ag concentrations. • Uptake and efflux rate constants for As and Ag were measured in caddisfly species. • Dietborne As was the predominant exposure route in two caddisfly species. • Diet was the only exposure route of bioaccumulated Ag in the investigated caddisflies. - Abstract: Biodynamic modeling was used to investigate the uptake and bioaccumulation of arsenic and silver from water and food by two Hydropsychid caddisfly larvae: Hydropsyche siltalai and Hydropsyche pellucidula. Radiotracer techniques determined the uptake rate constants of arsenic and silver from water, and assimilation efficiencies from food, and their subsequent loss rate constants after accumulation from either route. The uptake rate constants (±SE) of As and Ag from solution were 0.021 ± 0.005 and 0.350 ± 0.049 L g−1 day−1, respectively, for H. siltalai, and 0.435 ± 0.054 and 0.277 ± 0.021 L g−1 day−1, respectively, for H. pellucidula in moderately hard synthetic water at 10 °C. The assimilation efficiencies (±SE) of As and Ag from radiolabeled ingested food were 46.0 ± 7.7% and 75.7 ± 3.6%, respectively, for H. siltalai, and 61.0 ± 4.2% and 52.6 ± 8.6%, respectively, for H. pellucidula. Ag, but not As, AEs were significantly different between species. The AE of Ag differed from the AE of As in H. siltalai, but not in H. pellucidula. Mean efflux rate constants after accumulation of metals from solution or food ranged from 0.039 to 0.190 day−1. The efflux rate constants of As and Ag accumulated from solution were significantly lower than those of As and Ag assimilated from ingested food in both species. Experimentally derived ku and ke values were then used to predict As and Ag tissue concentrations in hydropsychids collected from 13 UK sites, including metal-contaminated streams in Cornwall. Arsenic and silver concentrations in environmental water and food (suspended particles) samples were

  4. Biosorption of Strontium from Simulated Nuclear Wastewater by Scenedesmus spinosus under Culture Conditions: Adsorption and Bioaccumulation Processes and Models

    OpenAIRE

    Mingxue Liu; Faqin Dong; Wu Kang; Shiyong Sun; Hongfu Wei; , Wei Zhang; Xiaoqin Nie; Yuting Guo; Ting Huang; Yuanyuan Liu

    2014-01-01

    Algae biosorption is an ideal wastewater treatment method when coupled with algae growth and biosorption. The adsorption and bioaccumulation of strontium from simulated nuclear wastewater by Scenedesmus spinosus were investigated in this research. One hundred mL of cultured S. spinosus cells with a dry weight of 1.0 mg in simulated nuclear wastewater were used to analyze the effects on S. spinosus cell growth as well as the adsorption and bioaccumulation characters under conditions of 25 ± 1 ...

  5. Predicting the resilience and recovery of aquatic systems: a framework for model evolution within environmental observatories

    Science.gov (United States)

    Hipsey, Matthew R.; Hamilton, David P.; Hanson, Paul C.; Carey, Cayelan C; Coletti, Janaine Z; Read, Jordan S.; Ibelings, Bas W; Valensini, Fiona J; Brookes, Justin D

    2015-01-01

    Maintaining the health of aquatic systems is an essential component of sustainable catchmentmanagement, however, degradation of water quality and aquatic habitat continues to challenge scientistsand policy-makers. To support management and restoration efforts aquatic system models are requiredthat are able to capture the often complex trajectories that these systems display in response to multiplestressors. This paper explores the abilities and limitations of current model approaches in meeting this chal-lenge, and outlines a strategy based on integration of flexible model libraries and data from observationnetworks, within a learning framework, as a means to improve the accuracy and scope of model predictions.The framework is comprised of a data assimilation component that utilizes diverse data streams from sensornetworks, and a second component whereby model structural evolution can occur once the model isassessed against theoretically relevant metrics of system function. Given the scale and transdisciplinarynature of the prediction challenge, network science initiatives are identified as a means to develop and inte-grate diverse model libraries and workflows, and to obtain consensus on diagnostic approaches to modelassessment that can guide model adaptation. We outline how such a framework can help us explore thetheory of how aquatic systems respond to change by bridging bottom-up and top-down lines of enquiry,and, in doing so, also advance the role of prediction in aquatic ecosystem management.

  6. Aquatic vegetation indices assessment through radiative transfer modeling and linear mixture simulation

    Science.gov (United States)

    Villa, Paolo; Mousivand, Alijafar; Bresciani, Mariano

    2014-08-01

    Although spectral vegetation indices (VIs) have been widely used for remote sensing of vegetation in general, such indices have been traditionally targeted at terrestrial, more than aquatic, vegetation. This study introduces two new VIs specifically targeted at aquatic vegetation: NDAVI and WAVI and assesses their performance in capturing information about aquatic vegetation features by comparison with pre-existing indices: NDVI, SAVI and EVI. The assessment methodology is based on: (i) theoretical radiative transfer modeling of vegetation canopy-backgrounds coupling, and (ii) spectral linear mixture simulation based on real-case endmembers. Two study areas, Lake Garda and Lakes of Mantua, in Northern Italy, and a multisensor dataset have been exploited for our study. Our results demonstrate the advantages of the new indices. In particular, NDAVI and WAVI sensitivity scores to LAI and LIDF parameters were generally higher than pre-existing indices' ones. Radiative transfer modeling and real-case based linear mixture simulation showed a general positive, non-linear correlation of vegetation indices with increasing LAI and vegetation fractional cover (FC), more marked for NDVI and NDAVI. Moreover, NDAVI and WAVI show enhanced capabilities in separating terrestrial from aquatic vegetation response, compared to pre-existing indices, especially of NDVI. The new indices provide good performance in distinguishing aquatic from terrestrial vegetation: NDAVI over low density vegetation (LAI 1.0, FC > 50%). Specific vegetation indices can therefore improve remote sensing applications for aquatic vegetation monitoring.

  7. Fuzzy model for risk assessment of persistent organic pollutants in aquatic ecosystems.

    Science.gov (United States)

    Seguí, X; Pujolasus, E; Betrò, S; Agueda, A; Casal, J; Ocampo-Duque, W; Rudolph, I; Barra, R; Páez, M; Barón, E; Eljarrat, E; Barceló, D; Darbra, R M

    2013-07-01

    We developed a model for evaluating the environmental risk of persistent organic pollutants (POPs) to aquatic organisms. The model is based on fuzzy theory and uses information provided by international experts through a questionnaire. It has been tested in two case studies for a particular type of POPs: brominated flame retardants (BFRs). The first case study is related to the EU-funded AQUATERRA project, with sampling campaigns carried out in two Ebro tributaries in Spain (the Cinca and Vero Rivers). The second one, named the BROMACUA project, assessed different aquatic ecosystems in Chile (San Vicente Bay) and Colombia (Santa Marta Marsh). In both projects, the BFRs under study were polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). However, the model can be extrapolated to other POPs and to different aquatic ecosystems to provide useful results for decision-makers. PMID:23524177

  8. Evaluating chemical exposure and effect models for aquatic species with a focus on crude oil constituents

    NARCIS (Netherlands)

    Hoop, L. de

    2016-01-01

    The aim of this PhD thesis is to evaluate a suite of exposure and effect models on their applicability in ecological risk assessment for aquatic species and ecosystems. The focus is on oil constituents, as it is largely unknown whether current ecological models are applicable to crude oil and its co

  9. Matrix Population Model for Estimating Effects from Time-Varying Aquatic Exposures: Technical Documentation

    Science.gov (United States)

    The Office of Pesticide Programs models daily aquatic pesticide exposure values for 30 years in its risk assessments. However, only a fraction of that information is typically used in these assessments. The population model employed herein is a deterministic, density-dependent pe...

  10. The behavior of 89Sr and tritium water (HTO) in a model terrestrial-aquatic ecosystem

    International Nuclear Information System (INIS)

    The effect of land polluted by 89Sr on water body and the immigration of HTO from water body to land were studied in a modelling terrestrial-aquatic ecosystem. The results are as follows: (1) The 89Sr in soil quickly migrated to common bean plants and its concentration in common bean plants was increasing with the time, but the concentration of 89Sr in soil was exponentially declining with the depth. About 5% of 89Sr was migrated to water body by rainfall then distributed to other components, and it can be concentrated by aquatics in a certain degree. (2) when HTO entered into the water body, it would migrate to other components of the ecosystem. and the HTO in the pool was linearly decreasing with the time. However, the concentration of HTO in the sediments and aquatics would firstly increase then reached the peak and went down. The tritium of HTO was existed in two forms in the sediments and aquatics, free water (HTO) and bound tritium. HTO was also migrated to the adjacent land soil and absorbed by land crop plants, within one and half months the land system contained 24% of the total tritium in the aquatic system

  11. Food Web Bioaccumulation Model for Resident Killer Whales from the Northeastern Pacific Ocean as a Tool for the Derivation of PBDE-Sediment Quality Guidelines.

    Science.gov (United States)

    Alava, Juan José; Ross, Peter S; Gobas, Frank A P C

    2016-01-01

    Resident killer whale populations in the NE Pacific Ocean are at risk due to the accumulation of pollutants, including polybrominated diphenyl ethers (PBDEs). To assess the impact of PBDEs in water and sediments in killer whale critical habitat, we developed a food web bioaccumulation model. The model was designed to estimate PBDE concentrations in killer whales based on PBDE concentrations in sediments and the water column throughout a lifetime of exposure. Calculated and observed PBDE concentrations exceeded the only toxicity reference value available for PBDEs in marine mammals (1500 μg/kg lipid) in southern resident killer whales but not in northern resident killer whales. Temporal trends (1993-2006) for PBDEs observed in southern resident killer whales showed a doubling time of ≈5 years. If current sediment quality guidelines available in Canada for polychlorinated biphenyls are applied to PBDEs, it can be expected that PBDE concentrations in killer whales will exceed available toxicity reference values by a large margin. Model calculations suggest that a PBDE concentration in sediments of approximately 1.0 μg/kg dw produces PBDE concentrations in resident killer whales that are below the current toxicity reference value for 95 % of the population, with this value serving as a precautionary benchmark for a management-based approach to reducing PBDE health risks to killer whales. The food web bioaccumulation model may be a useful risk management tool in support of regulatory protection for killer whales. PMID:26289814

  12. MOIRA models and methodologies for assessing the effectiveness of countermeasures in complex aquatic systems contaminated by radionuclides

    International Nuclear Information System (INIS)

    The present report is composed of a set of articles written by the partners of the MOIRA project (a model-based computerized system for management support to identify optimal remedial strategies for restoring radionuclide contaminated aquatic ecosystems and drainage areas). The report describes models for predicting the behaviour of radionuclides in complex aquatic systems and the effects of countermeasures for their restoration

  13. AquaEnv: an aquatic acid–base modelling environment in R

    NARCIS (Netherlands)

    Hofmann, A.F.; Soetaert, K.E.R.; Middelburg, J.J.; Meysman, F.J.R.

    2010-01-01

    AquaEnv is an integrated software package for aquatic chemical model generation focused on ocean acidification and antropogenic CO2 uptake. However, the package is not restricted to the carbon cycle or the oceans: it calculates, converts, and visualizes information necessary to describe pH, related

  14. Different modelling tools of aquatic ecosystems : a proposal for a unified approach

    OpenAIRE

    António Manuel Correia Pereira; Pedro Duarte; Alain Norro

    2006-01-01

    Over the last few decades, several modelling tools have been developed for the simulation of hydrodynamic and biogeochemical processes in aquatic ecosystems. Until late 70#8217;s, coupling hydrodynamic models to biogeochemical models was not common and today, problems linked to the different scales of interest remain. The time scale of hydrodynamic phenomena in coastal zone (minutes to hours) is much lower than that of biogeochemistry (few days). Over the last years, there has been an increas...

  15. Hyperspectral Aquatic Radiative Transfer Modeling Using a High-Performance Cluster Computing Based Approach

    Energy Technology Data Exchange (ETDEWEB)

    Fillippi, Anthony [Texas A& M University; Bhaduri, Budhendra L [ORNL; Naughton, III, Thomas J [ORNL; King, Amy L [ORNL; Scott, Stephen L [ORNL; Guneralp, Inci [Texas A& M University

    2012-01-01

    For aquatic studies, radiative transfer (RT) modeling can be used to compute hyperspectral above-surface remote sensing reflectance that can be utilized for inverse model development. Inverse models can provide bathymetry and inherent- and bottom-optical property estimation. Because measured oceanic field/organic datasets are often spatio-temporally sparse, synthetic data generation is useful in yielding sufficiently large datasets for inversion model development; however, these forward-modeled data are computationally expensive and time-consuming to generate. This study establishes the magnitude of wall-clock-time savings achieved for performing large, aquatic RT batch-runs using parallel computing versus a sequential approach. Given 2,600 simulations and identical compute-node characteristics, sequential architecture required {approx}100 hours until termination, whereas a parallel approach required only {approx}2.5 hours (42 compute nodes) - a 40x speed-up. Tools developed for this parallel execution are discussed.

  16. Hyperspectral Aquatic Radiative Transfer Modeling Using a High-Performance Cluster Computing-Based Approach

    Energy Technology Data Exchange (ETDEWEB)

    Filippi, Anthony M [ORNL; Bhaduri, Budhendra L [ORNL; Naughton, III, Thomas J [ORNL; King, Amy L [ORNL; Scott, Stephen L [ORNL; Guneralp, Inci [Texas A& M University

    2012-01-01

    Abstract For aquatic studies, radiative transfer (RT) modeling can be used to compute hyperspectral above-surface remote sensing reflectance that can be utilized for inverse model development. Inverse models can provide bathymetry and inherent-and bottom-optical property estimation. Because measured oceanic field/organic datasets are often spatio-temporally sparse, synthetic data generation is useful in yielding sufficiently large datasets for inversion model development; however, these forward-modeled data are computationally expensive and time-consuming to generate. This study establishes the magnitude of wall-clock-time savings achieved for performing large, aquatic RT batch-runs using parallel computing versus a sequential approach. Given 2,600 simulations and identical compute-node characteristics, sequential architecture required ~100 hours until termination, whereas a parallel approach required only ~2.5 hours (42 compute nodes) a 40x speed-up. Tools developed for this parallel execution are discussed.

  17. Cadmium accumulation in herbivorous and carnivorous small mammals: meta-analysis of field data and validation of the bioaccumulation model optomal modeling for ecotoxicological applications

    NARCIS (Netherlands)

    Veltman, K.; Huijbregts, M.A.J.; Hamers, T.; Wijnhoven, S.; Hendriks, A.J.

    2007-01-01

    Environmental risk assessment procedures often use bioaccumulation as a criterion for hazard identification of a polluted location. Field studies regarding metal concentrations in food chains, however, have provided widely different information, because accumulation is shown to vary between the extr

  18. Ecotoxicogenomic Approaches for Understanding Molecular Mechanisms of Environmental Chemical Toxicity Using Aquatic Invertebrate, Daphnia Model Organism

    Directory of Open Access Journals (Sweden)

    Hyo Jeong Kim

    2015-05-01

    Full Text Available Due to the rapid advent in genomics technologies and attention to ecological risk assessment, the term “ecotoxicogenomics” has recently emerged to describe integration of omics studies (i.e., transcriptomics, proteomics, metabolomics, and epigenomics into ecotoxicological fields. Ecotoxicogenomics is defined as study of an entire set of genes or proteins expression in ecological organisms to provide insight on environmental toxicity, offering benefit in ecological risk assessment. Indeed, Daphnia is a model species to study aquatic environmental toxicity designated in the Organization for Economic Co-operation and Development’s toxicity test guideline and to investigate expression patterns using ecotoxicology-oriented genomics tools. Our main purpose is to demonstrate the potential utility of gene expression profiling in ecotoxicology by identifying novel biomarkers and relevant modes of toxicity in Daphnia magna. These approaches enable us to address adverse phenotypic outcomes linked to particular gene function(s and mechanistic understanding of aquatic ecotoxicology as well as exploration of useful biomarkers. Furthermore, key challenges that currently face aquatic ecotoxicology (e.g., predicting toxicant responses among a broad spectrum of phytogenetic groups, predicting impact of temporal exposure on toxicant responses necessitate the parallel use of other model organisms, both aquatic and terrestrial. By investigating gene expression profiling in an environmentally important organism, this provides viable support for the utility of ecotoxicogenomics.

  19. Toxic metals in aquatic ecosystems: a microbiological perspective.

    Science.gov (United States)

    Ford, T; Ryan, D

    1995-02-01

    Microbe-metal interactions in aquatic environments and their exact role in transport and transformations of toxic metals are poorly understood. This paper will briefly review our understanding of these interactions. Ongoing research in Lake Chapala, Mexico, the major water source for the City of Guadalajara, provides an opportunity to study the microbiological aspects of metal-cycling in the water column. Constant resuspension of sediments provides a microbiologically rich aggregate-based system. Data indicate that toxic metals are concentrated on aggregate material and bioaccumulate in the food chain. A provisional model is presented for involvement of microbial aggregates in metal-cycling in Lake Chapala. PMID:7621793

  20. Daphnia as a model organism in limnology and aquatic biology: introductory remarks

    OpenAIRE

    Petrusek, Adam; Jaromir SEDA

    2011-01-01

    Cladocerans of the genus Daphnia are keystone pelagic filter feeders in many temperate ponds and lakes. They have also become popular model organisms in various biological disciplines, from aquatic ecology to biomedical sciences. The crucial features that make these organisms excellent experimental models are their cyclical parthenogenetic life cycle together with easy culturing and handling. Thanks to these characteristics, the number of publications dealing with Daphnia is rapidly growing. ...

  1. Announcement: Release of CDC's 2016 Model Aquatic Health Code, Second Edition and Revised Hyperchlorination and Fecal Incident Response Recommendations.

    Science.gov (United States)

    2016-01-01

    The 2016 Model Aquatic Health Code (MAHC), Second Edition was released on July 15, 2016 (http://www.cdc.gov/mahc/editions/current.html). MAHC is national guidance that can be voluntarily adopted by state and local jurisdictions to minimize the risk for illness and injury at public aquatic facilities through facility design, construction, operation, maintenance, and management. PMID:27442593

  2. Aquatic blues: modeling depression and antidepressant action in zebrafish.

    Science.gov (United States)

    Nguyen, Michael; Stewart, Adam Michael; Kalueff, Allan V

    2014-12-01

    Depression is a serious psychiatric condition affecting millions of patients worldwide. Unipolar depression is characterized by low mood, anhedonia, social withdrawal and other severely debilitating psychiatric symptoms. Bipolar disorder manifests in alternating depressed mood and 'hyperactive' manic/hypomanic states. Animal experimental models are an invaluable tool for research into the pathogenesis of bipolar/unipolar depression, and for the development of potential treatments. Due to their high throughput value, genetic tractability, low cost and quick reproductive cycle, zebrafish (Danio rerio) have emerged as a promising new model species for studying brain disorders. Here, we discuss the developing utility of zebrafish for studying depression disorders, and outline future areas of research in this field. We argue that zebrafish represent a useful model organism for studying depression and its behavioral, genetic and physiological mechanisms, as well as for anti-depressant drug discovery.

  3. Bioaccumulation and trophic magnification of pharmaceuticals and endocrine disruptors in a Mediterranean river food web.

    Science.gov (United States)

    Ruhí, Albert; Acuña, Vicenç; Barceló, Damià; Huerta, Belinda; Mor, Jordi-Rene; Rodríguez-Mozaz, Sara; Sabater, Sergi

    2016-01-01

    Increasing evidence exists that emerging pollutants such as pharmaceuticals (PhACs) and endocrine-disrupting compounds (EDCs) can be bioaccumulated by aquatic organisms. However, the relative role of trophic transfers in the acquisition of emerging pollutants by aquatic organisms remains largely unexplored. In freshwater ecosystems, wastewater treatment plants are a major source of PhACs and EDCs. Here we studied the entrance of emerging pollutants and their flow through riverine food webs in an effluent-influenced river. To this end we assembled a data set on the composition and concentrations of a broad spectrum of PhACs (25 compounds) and EDCs (12 compounds) in water, biofilm, and three aquatic macroinvertebrate taxa with different trophic positions and feeding strategies (Ancylus fluviatilis, Hydropsyche sp., Phagocata vitta). We tested for similarities in pollutant levels among these compartments, and we compared observed bioaccumulation factors (BAFs) to those predicted by a previously-developed empirical model based on octanol-water distribution coefficients (Dow). Despite a high variation in composition and levels of emerging pollutants across food web compartments, observed BAFs in Hydropsyche and Phagocata matched, on average, those already predicted. Three compounds (the anti-inflammatory drug diclofenac, the lipid regulator gemfibrozil, and the flame retardant TBEP) were detected in water, biofilm and (at least) one macroinvertebrate taxa. TBEP was the only compound present in all taxa and showed magnification across trophic levels. This suggests that prey consumption may be, in some cases, a significant exposure route. This study advances the notion that both waterborne exposure and trophic interactions need to be taken into account when assessing the potential ecological risks of emerging pollutants in aquatic ecosystems. PMID:26170111

  4. A log-normal distribution model for the molecular weight of aquatic fulvic acids

    Science.gov (United States)

    Cabaniss, S.E.; Zhou, Q.; Maurice, P.A.; Chin, Y.-P.; Aiken, G.R.

    2000-01-01

    The molecular weight of humic substances influences their proton and metal binding, organic pollutant partitioning, adsorption onto minerals and activated carbon, and behavior during water treatment. We propose a lognormal model for the molecular weight distribution in aquatic fulvic acids to provide a conceptual framework for studying these size effects. The normal curve mean and standard deviation are readily calculated from measured M(n) and M(w) and vary from 2.7 to 3 for the means and from 0.28 to 0.37 for the standard deviations for typical aquatic fulvic acids. The model is consistent with several types of molecular weight data, including the shapes of high- pressure size-exclusion chromatography (HP-SEC) peaks. Applications of the model to electrostatic interactions, pollutant solubilization, and adsorption are explored in illustrative calculations.The molecular weight of humic substances influences their proton and metal binding, organic pollutant partitioning, adsorption onto minerals and activated carbon, and behavior during water treatment. We propose a log-normal model for the molecular weight distribution in aquatic fulvic acids to provide a conceptual framework for studying these size effects. The normal curve mean and standard deviation are readily calculated from measured Mn and Mw and vary from 2.7 to 3 for the means and from 0.28 to 0.37 for the standard deviations for typical aquatic fulvic acids. The model is consistent with several type's of molecular weight data, including the shapes of high-pressure size-exclusion chromatography (HP-SEC) peaks. Applications of the model to electrostatic interactions, pollutant solubilization, and adsorption are explored in illustrative calculations.

  5. Modeling the ecological impact of heavy metals on aquatic ecosystems: a framework for the development of an ecological model.

    Science.gov (United States)

    He, M; Wang, Z; Tang, H

    2001-02-01

    In this paper, an ecological model is proposed to predict the effects of heavy metals on aquatic ecosystems. The bioavailable concentration of metals and a concept of toxicity strength (TS) are combined. The integrated ecological model relates the transport, distribution and speciation of heavy metals and their toxicity, and the effect of environmental variability on metal toxicity. It also emphasizes the link between physical and chemical processes of heavy metals in rivers and ecological effects. Based on the data obtained from research in the CERP project (Co-operative Ecological Research Project), the ecological impact of heavy metals on the aquatic ecosystem of the Le An River (polluted by heavy metals from a copper mine) was predicted. The results show that the estimated values of toxicity strength for surface water are in agreement with the percentage inhibition for the test organism (P. phosphoreum) and that the predicted ecological effect of polluted sediment is consistent with natural variability in aquatic ecosystems. PMID:11258829

  6. Assessment of Mercury Bioaccumulation in Zebra Cichlid (Cichlasoma Nigrofasciatum) Exposed to Sublethal Concentrations of Permethrin

    OpenAIRE

    Mahdi Banaee; Amal Beitsayah; Isar Jorabdoz

    2014-01-01

    Background: Aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. Mercury is a toxic metal with no known biological benefit to organisms. Bioavailability of mercury in aquatic environments depends on biological and non-biological parameters including other pollutants. Therefore, the objectives of this research were to determine the ef...

  7. Uranium bioaccumulation and biological disorders induced in zebrafish (Danio rerio) after a depleted uranium waterborne exposure

    Energy Technology Data Exchange (ETDEWEB)

    Barillet, Sabrina, E-mail: sabrina.barillet@free.f [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Adam-Guillermin, Christelle, E-mail: christelle.adam-guillermin@irsn.f [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Palluel, Olivier, E-mail: olivier.palluel@ineris.f [Ecotoxicological Risk Assessment Unit, INERIS (National Institute for Industrial Environment and Risks), Parc technologique ALATA, 60 550 Verneuil-en-Halatte (France); Porcher, Jean-Marc, E-mail: jean-marc.porcher@ineris.f [Ecotoxicological Risk Assessment Unit, INERIS (National Institute for Industrial Environment and Risks), Parc technologique ALATA, 60 550 Verneuil-en-Halatte (France); Devaux, Alain, E-mail: alain.devaux@entpe.f [Universite de Lyon, INRA, EFPA-SA, Environmental Science Laboratory (LSE), ENTPE, 69518 Vaulx en Velin cedex (France)

    2011-02-15

    Because of its toxicity and its ubiquity within aquatic compartments, uranium (U) represents a significant hazard to aquatic species such as fish. In a previous study, we investigated some biological responses in zebrafish either exposed to depleted or to enriched U (i.e., to different radiological activities). However, results required further experiments to better understand biological responses. Moreover, we failed to clearly demonstrate a significant relationship between biological effects and U radiological activity. We therefore chose to herein examine U bioaccumulation and induced effects in zebrafish according to a chemical dose-response approach. Results showed that U is highly bioconcentrated in fish, according to a time- and concentration-dependent model. Additionally, hepatic antioxidant defenses, red blood cells DNA integrity and brain acetylcholinesterase activity were found to be significantly altered. Generally, the higher the U concentration, the sooner and/or the greater the effect, suggesting a close relationship between accumulation and effect. - Research highlights: Depleted U bioconcentration factor is of about 1000 in zebrafish exposed to 20 {mu}g/L. Hepatic antioxidant disorders are noticed as soon as the first hours of exposure. DNA damage is induced in red blood cells after 20 d of exposure to 500 {mu}g DU/L. The brain cholinergic system (AChE activity) is impacted. - This study demonstrates that U is highly bioaccumulated in fish, resulting in biological disorders such as hepatic oxidative stress as well as genotoxic and neurotoxic events.

  8. Uranium bioaccumulation and biological disorders induced in zebrafish (Danio rerio) after a depleted uranium waterborne exposure

    International Nuclear Information System (INIS)

    Because of its toxicity and its ubiquity within aquatic compartments, uranium (U) represents a significant hazard to aquatic species such as fish. In a previous study, we investigated some biological responses in zebrafish either exposed to depleted or to enriched U (i.e., to different radiological activities). However, results required further experiments to better understand biological responses. Moreover, we failed to clearly demonstrate a significant relationship between biological effects and U radiological activity. We therefore chose to herein examine U bioaccumulation and induced effects in zebrafish according to a chemical dose-response approach. Results showed that U is highly bioconcentrated in fish, according to a time- and concentration-dependent model. Additionally, hepatic antioxidant defenses, red blood cells DNA integrity and brain acetylcholinesterase activity were found to be significantly altered. Generally, the higher the U concentration, the sooner and/or the greater the effect, suggesting a close relationship between accumulation and effect. - Research highlights: → Depleted U bioconcentration factor is of about 1000 in zebrafish exposed to 20 μg/L. → Hepatic antioxidant disorders are noticed as soon as the first hours of exposure. → DNA damage is induced in red blood cells after 20 d of exposure to 500 μg DU/L. → The brain cholinergic system (AChE activity) is impacted. - This study demonstrates that U is highly bioaccumulated in fish, resulting in biological disorders such as hepatic oxidative stress as well as genotoxic and neurotoxic events.

  9. Microcystin-LR bioaccumulation and depuration kinetics in lettuce and arugula: Human health risk assessment.

    Science.gov (United States)

    Cordeiro-Araújo, Micheline Kézia; Chia, Mathias Ahii; Arruda-Neto, João Dias de Toledo; Tornisielo, Valdemar Luiz; Vilca, Franz Zirena; Bittencourt-Oliveira, Maria do Carmo

    2016-10-01

    Microcystin-LR (MC-LR) is one of the most toxic and common microcystins (MCs) variant found in aquatic ecosystems. Little is known about the possibility of recovering microcystins contaminated agricultural crops. The objectives of this study were to determine the bioaccumulation and depuration kinetics of MC-LR in leaf tissues of lettuce and arugula, and estimate the total daily intake (ToDI) of MC-LR via contaminated vegetables by humans. Arugula and lettuce were irrigated with contaminated water having 5 and 10μgL(-1) of MC-LR for 7days (bioaccumulation), and subsequently, with uncontaminated water for 7days (depuration). Quantification of MC-LR was performed by LC-MS/MS. The one-compartment biokinetic model was employed for MC-LR bioaccumulation and depuration data analysis. MC-LR was only accumulated in lettuce. After 7days of irrigation with uncontaminated water, over 25% of accumulated MC-LR was still retained in leaf tissues of plants treated with 10μgL(-1) MC-LR. Total daily toxin intake by adult consumers (60kg-bw) exceeded the 0.04μgMC-LRkg(-1) limit recommended by WHO. Bioaccumulation was found to be linearly proportional to the exposure concentration of the toxin, increasing over time; and estimated to become saturated after 30days of uninterrupted exposure. On the other hand, MC-LR depuration was less efficient at higher exposure concentrations. This is because biokinetic half-life calculations gave 2.9 and 3.7days for 5 and 10μgL(-1) MC-LR treatments, which means 29-37days are required to eliminate the toxin. For the first time, our results demonstrated the possibility of MC-LR decontamination of lettuce plants.

  10. Microcystin-LR bioaccumulation and depuration kinetics in lettuce and arugula: Human health risk assessment.

    Science.gov (United States)

    Cordeiro-Araújo, Micheline Kézia; Chia, Mathias Ahii; Arruda-Neto, João Dias de Toledo; Tornisielo, Valdemar Luiz; Vilca, Franz Zirena; Bittencourt-Oliveira, Maria do Carmo

    2016-10-01

    Microcystin-LR (MC-LR) is one of the most toxic and common microcystins (MCs) variant found in aquatic ecosystems. Little is known about the possibility of recovering microcystins contaminated agricultural crops. The objectives of this study were to determine the bioaccumulation and depuration kinetics of MC-LR in leaf tissues of lettuce and arugula, and estimate the total daily intake (ToDI) of MC-LR via contaminated vegetables by humans. Arugula and lettuce were irrigated with contaminated water having 5 and 10μgL(-1) of MC-LR for 7days (bioaccumulation), and subsequently, with uncontaminated water for 7days (depuration). Quantification of MC-LR was performed by LC-MS/MS. The one-compartment biokinetic model was employed for MC-LR bioaccumulation and depuration data analysis. MC-LR was only accumulated in lettuce. After 7days of irrigation with uncontaminated water, over 25% of accumulated MC-LR was still retained in leaf tissues of plants treated with 10μgL(-1) MC-LR. Total daily toxin intake by adult consumers (60kg-bw) exceeded the 0.04μgMC-LRkg(-1) limit recommended by WHO. Bioaccumulation was found to be linearly proportional to the exposure concentration of the toxin, increasing over time; and estimated to become saturated after 30days of uninterrupted exposure. On the other hand, MC-LR depuration was less efficient at higher exposure concentrations. This is because biokinetic half-life calculations gave 2.9 and 3.7days for 5 and 10μgL(-1) MC-LR treatments, which means 29-37days are required to eliminate the toxin. For the first time, our results demonstrated the possibility of MC-LR decontamination of lettuce plants. PMID:27267723

  11. TAME - the terrestrial-aquatic model of the environment: model definition

    Energy Technology Data Exchange (ETDEWEB)

    Klos, R.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Mueller-Lemans, H. [Tergoso AG fuer Umweltfragen, Sargans (Switzerland); Dorp, F. van [Nationale Genossenschaft fuer die Lagerung Radioaktiver Abfaelle (NAGRA), Baden (Switzerland); Gribi, P. [Colenco AG, Baden (Switzerland)

    1996-10-01

    TAME - the Terrestrial-Aquatic Model of the Environment is a new computer model for use in assessments of the radiological impact of the release of radionuclides to the biosphere, following their disposal in underground waste repositories. Based on regulatory requirements, the end-point of the calculations is the maximum annual individual dose to members of a hypothetical population group inhabiting the biosphere region. Additional mid- and end-points in the TAME calculations are dose as function of time from eleven exposure pathways, foodstuff concentrations and the distribution of radionuclides in the modelled biosphere. A complete description of the mathematical representations of the biosphere in TAME is given in this document, based on a detailed review of the underlying conceptual framework for the model. Example results are used to illustrate features of the conceptual and mathematical models. The end-point of dose is shown to be robust for the simplifying model assumptions used to define the biosphere for the example calculations. TAME comprises two distinct sub-models - one representing the transport of radionuclides in the near-surface environment and one for the calculation of dose to individual inhabitants of that biosphere. The former is the result of a detailed review of the modelling requirements for such applications and is based on a comprehensive consideration of all features, events and processes (FEPs) relevant to Swiss biospheres, both in the present-day biosphere and in potential future biosphere states. Representations of the transport processes are derived from first principles. Mass balance for water and solid material fluxes is used to determine the rates of contaminant transfer between components of the biosphere system. The calculation of doses is based on existing representations of exposure pathways and draws on experience both from Switzerland and elsewhere. (author) figs., tabs., refs.

  12. TAME - the terrestrial-aquatic model of the environment: model definition

    International Nuclear Information System (INIS)

    TAME - the Terrestrial-Aquatic Model of the Environment is a new computer model for use in assessments of the radiological impact of the release of radionuclides to the biosphere, following their disposal in underground waste repositories. Based on regulatory requirements, the end-point of the calculations is the maximum annual individual dose to members of a hypothetical population group inhabiting the biosphere region. Additional mid- and end-points in the TAME calculations are dose as function of time from eleven exposure pathways, foodstuff concentrations and the distribution of radionuclides in the modelled biosphere. A complete description of the mathematical representations of the biosphere in TAME is given in this document, based on a detailed review of the underlying conceptual framework for the model. Example results are used to illustrate features of the conceptual and mathematical models. The end-point of dose is shown to be robust for the simplifying model assumptions used to define the biosphere for the example calculations. TAME comprises two distinct sub-models - one representing the transport of radionuclides in the near-surface environment and one for the calculation of dose to individual inhabitants of that biosphere. The former is the result of a detailed review of the modelling requirements for such applications and is based on a comprehensive consideration of all features, events and processes (FEPs) relevant to Swiss biospheres, both in the present-day biosphere and in potential future biosphere states. Representations of the transport processes are derived from first principles. Mass balance for water and solid material fluxes is used to determine the rates of contaminant transfer between components of the biosphere system. The calculation of doses is based on existing representations of exposure pathways and draws on experience both from Switzerland and elsewhere. (author) figs., tabs., refs

  13. Aquatic dispersion modelling of a tritium plume in Lake Ontario

    International Nuclear Information System (INIS)

    Approximately 2900 kg of tritiated water, containing 2.3E+15 Bq of tritium, were released to Lake Ontario via the cooling water discharge when a leak developed in a moderator heat exchanger in Unit 1 at the Pickering Nuclear Generating Station (PNGS) on 1992 August 2. The release provided the opportunity to study the dispersion of a tritium plume in the coastal zone of Lake Ontario. Current direction over the two-week period following the release was predominantly parallel to the shore, and elevated tritium concentrations were observed up to 20 km east and 85 km west of the PNGS. Predictions of the tritium plume movement were made using current velocity measurements taken at 8-m depth, 2.5 km offshore from Darlington and using a empirical relationship where alongshore current speed is assumed to be proportional to the alongshore component of the wind speed. The tritium migration was best described using current velocity measurements. The tritium plume dispersion is modelled using the one-dimensional advection-dispersion equation. Transport parameters are the alongshore current speed and longitudinal dispersion coefficient. Longitudinal dispersion coefficients, estimated by fitting the solution of the advection-dispersion equation to measured concentration distance profiles ranged from 3.75 to 10.57 m2s-1. Simulations using the fitted values of the dispersion coefficient were able to describe maximum tritium concentrations measured at water supply plants located within 25 km of Pickering to within a factor of 3. The dispersion coefficient is a function of spatial and temporal variability in current velocity and the fitted dispersion coefficients estimated here may not be suitable for predicting tritium plume dispersion under different current conditions. The sensitivity of the dispersion coefficient to variability in current conditions should be evaluated in further field experiments. (author). 13 refs., 7 tabs., 12 figs

  14. Predicting aquatic toxicities of chemical pesticides in multiple test species using nonlinear QSTR modeling approaches.

    Science.gov (United States)

    Basant, Nikita; Gupta, Shikha; Singh, Kunwar P

    2015-11-01

    In this study, we established nonlinear quantitative-structure toxicity relationship (QSTR) models for predicting the toxicities of chemical pesticides in multiple aquatic test species following the OECD (Organization for Economic Cooperation and Development) guidelines. The decision tree forest (DTF) and decision tree boost (DTB) based QSTR models were constructed using a pesticides toxicity dataset in Selenastrum capricornutum and a set of six descriptors. Other six toxicity data sets were used for external validation of the constructed QSTRs. Global QSTR models were also constructed using the combined dataset of all the seven species. The diversity in chemical structures and nonlinearity in the data were evaluated. Model validation was performed deriving several statistical coefficients for the test data and the prediction and generalization abilities of the QSTRs were evaluated. Both the QSTR models identified WPSA1 (weighted charged partial positive surface area) as the most influential descriptor. The DTF and DTB QSTRs performed relatively better than the single decision tree (SDT) and support vector machines (SVM) models used as a benchmark here and yielded R(2) of 0.886 and 0.964 between the measured and predicted toxicity values in the complete dataset (S. capricornutum). The QSTR models applied to six other aquatic species toxicity data yielded R(2) of >0.92 (DTF) and >0.97 (DTB), respectively. The prediction accuracies of the global models were comparable with those of the S. capricornutum models. The results suggest for the appropriateness of the developed QSTR models to reliably predict the aquatic toxicity of chemicals and can be used for regulatory purpose.

  15. Models and parameters for environmental radiological assessments

    International Nuclear Information System (INIS)

    This book presents a unified compilation of models and parameters appropriate for assessing the impact of radioactive discharges to the environment. Models examined include those developed for the prediction of atmospheric and hydrologic transport and deposition, for terrestrial and aquatic food-chain bioaccumulation, and for internal and external dosimetry. Chapters have been entered separately into the data base

  16. Models and parameters for environmental radiological assessments

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C W [ed.

    1984-01-01

    This book presents a unified compilation of models and parameters appropriate for assessing the impact of radioactive discharges to the environment. Models examined include those developed for the prediction of atmospheric and hydrologic transport and deposition, for terrestrial and aquatic food-chain bioaccumulation, and for internal and external dosimetry. Chapters have been entered separately into the data base. (ACR)

  17. From terrestrial to aquatic fluxes: Integrating stream dynamics within a dynamic global vegetation modeling framework

    Science.gov (United States)

    Hoy, Jerad; Poulter, Benjamin; Emmett, Kristen; Cross, Molly; Al-Chokhachy, Robert; Maneta, Marco

    2016-04-01

    Integrated terrestrial ecosystem models simulate the dynamics and feedbacks between climate, vegetation, disturbance, and hydrology and are used to better understand biogeography and biogeochemical cycles. Extending dynamic vegetation models to the aquatic interface requires coupling surface and sub-surface runoff to catchment routing schemes and has the potential to enhance how researchers and managers investigate how changes in the environment might impact the availability of water resources for human and natural systems. In an effort towards creating such a coupled model, we developed catchment-based hydrologic routing and stream temperature model to pair with LPJ-GUESS, a dynamic global vegetation model. LPJ-GUESS simulates detailed stand-level vegetation dynamics such as growth, carbon allocation, and mortality, as well as various physical and hydrologic processes such as canopy interception and through-fall, and can be applied at small spatial scales, i.e., 1 km. We demonstrate how the coupled model can be used to investigate the effects of transient vegetation dynamics and CO2 on seasonal and annual stream discharge and temperature regimes. As a direct management application, we extend the modeling framework to predict habitat suitability for fish habitat within the Greater Yellowstone Ecosystem, a 200,000 km2 region that provides critical habitat for a range of aquatic species. The model is used to evaluate, quantitatively, the effects of management practices aimed to enhance hydrologic resilience to climate change, and benefits for water storage and fish habitat in the coming century.

  18. Modeling the potential effects of atrazine on aquatic communities in midwestern streams.

    Science.gov (United States)

    Bartell, Steven M; Brain, Richard A; Hendley, Paul; Nair, Shyam K

    2013-10-01

    The comprehensive aquatic systems model for atrazine (CASM(ATZ)) estimates the potential toxic effects of atrazine on populations of aquatic plants and consumers in a generic lower-order midwestern stream. The CASM(ATZ) simulates the daily production of 20 periphyton and 6 aquatic vascular plant species. The modeled consumer community consists of 17 functionally defined species of zooplankton, benthic invertebrates, bacteria, and fish. Daily values of population biomass (grams of carbon per square meter) are calculated as nonlinear functions of population bioenergetics, physical-chemical environmental parameters, grazing/predator-prey interactions, and population-specific direct and indirect responses to atrazine. The CASM(ATZ) uses Monte Carlo methods to characterize the implications of phenotypic variability, environmental variability, and uncertainty associated with atrazine toxicity data in estimating the potential impacts of time-varying atrazine exposures on population biomass and community structure. Comparisons of modeled biomass values for plants and consumers with published data indicate that the generic reference simulation realistically describes ecological production in lower-order midwestern streams. Probabilistic assessments were conducted using the CASM(ATZ) to evaluate potential modeled changes in plant community structure resulting from measured atrazine exposure profiles in 3 midwestern US streams representing watersheds highly vulnerable to runoff. Deviation in the median values of maximum 30-d average Steinhaus similarity index ranged from 0.09% to 2.52% from the reference simulation. The CASM(ATZ) could therefore be used for the purposes of risk assessment by comparison of site monitoring-based model output to a biologically relevant Steinhaus similarity index level of concern. Used as a generic screening technology or in site-specific applications, the CASM(AT) provides an effective, coherent, and transparent modeling framework for assessing

  19. The Price Model of Aquatic Products Based on Predictive Control Theory

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper discusses a disequilibrium cobweb model of price of aquatic products, and applies predictive control theory, so that the system operates stably, and the deviation between supply and demand of aquatic products smoothly tracks the pre-given target. It defines the supply and demand change model, and researches the impact of parameter selection in this model on dynamic state and robustness of the system. I conduct simulation by Matlab software, to get the response curve of this model. The results show that in the early period of commodities coming into the market, affected by lack of market information and many other factors, the price fluctuates greatly in a short time. The market will gradually achieve balance between supply and demand over time, and the price fluctuations in the neighbouring two periods are broadly consistent. The increase in model parameter can decrease overshoot, to promote the stability of system, but the slower the dynamic response, the longer the deviation between supply and demand to accurately track a given target. Therefore, by selecting different parameters, the decision-makers can establish different models of supply and demand changes to meet the actual needs, and ensure stable development of market. Simulation results verify the excellent performance of this algorithm.

  20. Toward the development of generally applicable models of the microbial loop in aquatic ecosystems.

    Science.gov (United States)

    Hopkinson, C S; Vallino, J J

    1994-09-01

    Simulation modeling has been an integral, albeit ad hoc, component of the field of aquatic microbial ecology for the past two decades. One of the most critical steps in simulation modeling is the initial formulation of a clear set of questions and goals. It is doubtful that a single generic model could be constructed to address adequately all questions of interest concerning the microbial loop because of the tremendous range in time scales that define these questions. Progress in the field of aquatic microbial ecology will benefit from an integrated research program including experimental and modeling approaches. A submodel of bacterial utilization of various qualities of organic matter that we have under construction is presented. This submodel will be a component of a larger model to evaluate the effects of quality and quantity of organic matter and inorganic nutrient inputs on estuarine food web structure and efficiency. The overall model will be general enough in its structure that it should be applicable to a wide range of questions concerning the microbial loop, with time scales ranging from hours to days. PMID:24186460

  1. Modeling an aquatic ecosystem: application of an evolutionary algorithm with genetic doping to reduce prediction uncertainty

    Science.gov (United States)

    Friedel, Michael; Buscema, Massimo

    2016-04-01

    Aquatic ecosystem models can potentially be used to understand the influence of stresses on catchment resource quality. Given that catchment responses are functions of natural and anthropogenic stresses reflected in sparse and spatiotemporal biological, physical, and chemical measurements, an ecosystem is difficult to model using statistical or numerical methods. We propose an artificial adaptive systems approach to model ecosystems. First, an unsupervised machine-learning (ML) network is trained using the set of available sparse and disparate data variables. Second, an evolutionary algorithm with genetic doping is applied to reduce the number of ecosystem variables to an optimal set. Third, the optimal set of ecosystem variables is used to retrain the ML network. Fourth, a stochastic cross-validation approach is applied to quantify and compare the nonlinear uncertainty in selected predictions of the original and reduced models. Results are presented for aquatic ecosystems (tens of thousands of square kilometers) undergoing landscape change in the USA: Upper Illinois River Basin and Central Colorado Assessment Project Area, and Southland region, NZ.

  2. Development of a dynamic energy budget modeling approach to investigate the effects of temperature and resource limitation on mercury bioaccumulation in Fundulus heteroclitus.

    Science.gov (United States)

    Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we are developing growth and bioaccumulation studies that contrib...

  3. Development of a dynamic energy budget modeling approach to investigate the effects of temperature and resource limitation on mercury bioaccumulation in Fundulus heteroclitus-presentation

    Science.gov (United States)

    Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we are conducting growth and bioaccumulation studies that contrib...

  4. Risk assessment of butyltins based on a fugacity-based food web bioaccumulation model in the Jincheng Bay mariculture area: II. Risk assessment.

    Science.gov (United States)

    Hu, Yanbing; Song, Xiukai; Gong, Xianghong; Xu, Yingjiang; Liu, Huihui; Deng, Xuxiu; Ru, Shaoguo

    2014-08-01

    A fugacity-based food web bioaccumulation model was constructed, and the biotic concentrations of butyltins in the food web of the Jincheng Bay mariculture area were estimated accordingly, using the water and sediment concentrations described in the accompanying paper (Part I). This paper presents an ecological risk assessment (ERA) and a human health risk assessment (HHRA) of the butyltins, based on the estimated tissue residues in the marine life in this area. The results showed that the ecological risk probability was greater than 0.05. At this level, management control is critical since sensitive marine species would be profoundly endangered by butyltin contamination. Few if any detrimental effects, however, would be generated for humans from exposure to butyltins through seafood consumption. The fugacity-based model can refine the ERA and HHRA of pollutants in marine areas, provide a basis for protecting marine ecology and the security of fishery products, and thus help determine the feasibility of a proposed aquaculture project. PMID:24947127

  5. Evaluation and modeling of the parameters affecting fluoride toxicity level in aquatic environments by bioassay method

    Directory of Open Access Journals (Sweden)

    Hamid Reza Shamsollahi

    2014-04-01

    Full Text Available Background: Fluoride exists in various forms in nature and water resources. , The rising level of fluoride in water resources due to discharge of industrial effluents can cause toxicity in aquatic organisms. To prevent toxicity, it is necessary to determine maximum fluoride toxicity as well as effluent discharge limits. The aim of this study was to determine the maximum fluoride toxicity and the factors affecting fluoride toxicity to provide a model in order to determine the effluent discharge limits. Methods: Daphnia magna bioassay in the absence of confounding factors was used to determine the maximum level of fluoride toxicity. Then, bioassay was repeated in the presence of the confounding factors (hardness, temperature and exposure time to determine their effects. Results: In the absence of intervening factors, fluoride LC50 levels determined after 24, 48 and 72 hours exposure were 4.9, 46.5 and 38.7 mg/l, respectively.. Also, the influence of confounding factors on LC50 values was reported significant by Minitab software. Conclusion: Increasing the water hardness reduced fluoride toxicity, and increasing the water temperature and exposure time increased fluoride toxicity in aquatic environments. Therefore, while determining the wastewater discharge limit in terms of fluoride concentration, it is essential to take the effect of confounding factors on fluoride toxicity into account in order to prevent toxicity in the open water resources.

  6. MOIRA models and methodologies for assessing the effectiveness of countermeasures in complex aquatic systems contaminated by radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Monte, L. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente; Brittain, J.E. [Oslo Univ., Oslo (Norway); Zoological Museum, Oslo (Norway); Haakanson, L. [Uppsala Univ., Uppsala (Sweden). Inst. of Earth Science; Gallego Diaz, E. [Madrid Univ. Politecnica, Madrid (Spain). Dept. de Ingenieria Nuclear

    1999-07-01

    The present report is composed of a set of articles written by the partners of the MOIRA project (a model-based computerized system for management support to identify optimal remedial strategies for restoring radionuclide contaminated aquatic ecosystems and drainage areas). The report describes models for predicting the behaviour of radionuclides in complex aquatic systems and the effects of countermeasures for their restoration. [Italian] Il rapporto contiene articoli preparati nell'ambito del progetto MOIRA (a model-based computerized system for management support to identify optimal remedial strategies for restoring radionuclide contaminated aquatic ecosystems and drainage areas), che descrive alcuni modelli per la previsione del comportamento di radionuclidi in sistemi acquatici complessi e per la valutazione dell'effetto delle contromisure per il loro recupero.

  7. Biodynamic modelling of the bioaccumulation of trace metals (Ag, As and Zn) by an infaunal estuarine invertebrate, the clam Scrobicularia plana

    International Nuclear Information System (INIS)

    Highlights: • Biodynamic modelling is used to predict accumulation of Ag, As and Zn in S. plana. • Dissolved and sediment-associated metals contribute to total metal bioaccumulation. • Relative importance varies with water and sediment concentrations and geochemistries. - Abstract: Biodynamic modelling was used to investigate the uptake and accumulation of three trace metals (Ag, As, Zn) by the deposit feeding estuarine bivalve mollusc Scrobicularia plana. Radioactive labelling techniques were used to quantify the rates of trace metal uptake (and subsequent elimination) from water and sediment diet. The uptake rate constant from solution (±SE) was greatest for Ag (3.954 ± 0.375 l g−1 d−1) followed by As (0.807 ± 0.129 l g−1 d−1) and Zn (0.103 ± 0.016 l g−1 d−1). Assimilation efficiencies from ingested sediment were 40.2 ± 1.3% (Ag), 31.7 ± 1.0% (Zn) and 25.3 ± 0.9% (As). Efflux rate constants after exposure to metals in the solution or sediment fell in the range of 0.014–0.060 d−1. By incorporating these physiological parameters into biodynamic models, our results showed that dissolved metal is the predominant source of accumulated Ag, As and Zn in S. plana, accounting for 66–99%, 50–97% and 52–98% of total accumulation of Ag, As and Zn, respectively, under different field exposure conditions. In general, model-predicted steady state concentrations of Ag, As and Zn matched well with those observed in clams collected in SW England estuaries. Our findings highlight the potential of biodynamic modelling to predict Ag, As and Zn accumulation in S. plana, taking into account specific dissolved and sediment concentrations of the metals at a particular field site, together with local water and sediment geochemistries

  8. Next Generation Framework for Aquatic Modeling of the Earth System (NextFrAMES)

    Science.gov (United States)

    Fekete, B. M.; Wollheim, W. M.; Lakhankar, T.; Vorosmarty, C. J.

    2008-12-01

    Earth System model development is becoming an increasingly complex task. As scientists attempt to represent the physical and bio-geochemical processes and various feedback mechanisms in unprecedented detail, the models themselves are becoming increasingly complex. At the same time, the surrounding IT infrastructure needed to carry out these detailed model computations is growing increasingly complex as well. To be accurate and useful, Earth System models must manage a vast amount of data in heterogenous computing environments ranging from single CPU systems to Beowulf type computer clusters. Scientists developing Earth System models increasingly confront obstacles associated with IT infrastructure. Numerous development efforts are on the way to ease that burden and offer model development platforms that reduce IT challenges and allow scientists to focus on their science. While these new modeling frameworks (e.g. FMS, ESMF, CCA, OpenMI) do provide solutions to many IT challenges (performing input/output, managing space and time, establishing model coupling, etc.), they are still considerably complex and often have steep learning curves. Over the course of the last fifteen years ,the University of New Hampshire developed several modeling frameworks independently from the above-mentioned efforts (Data Assembler, Frameworks for Aquatic Modeling of the Earth System and NextFrAMES which is continued at CCNY). While the UNH modeling frameworks have numerous similarities to those developed by other teams, these frameworks, in particular the latest NextFrAMES, represent a novel model development paradigm. While other modeling frameworks focus on providing services to modelers to perform various tasks, NextFrAMES strives to hide all of those services and provide a new approach for modelers to express their scientific thoughts. From a scientific perspective, most models have two core elements: the overall model structure (defining the linkages between the simulated processes

  9. Avaliação do destino e bioacumulação de benzo(apireno através de simulação computacional Assessment of fate and bioaccumulation of benzo(apirene by computer modeling

    Directory of Open Access Journals (Sweden)

    Sandro Froehner

    2008-01-01

    Full Text Available The objective of this work was to evaluate the environmental distribution of benzo(apirene, a polycyclic aromatic hydrocarbon, by the EQC model. The modeling of the contaminant distribution was accomplished by means of the fugacity model applied to a hypothetical scenario constituted by air, water, soil and sediment. The modeling and simulations revealed that the soil is the preferential compartment. We also discuss the implications of the results about fate and ecological risks associated with benzo(apirene. We concluded that the emissions of HPAs can not be ignored and bioaccumulation among others risks can be induced.

  10. Aquatic models for the study of renal transport function and pollutant toxicity.

    Science.gov (United States)

    Miller, D S

    1987-04-01

    Studies of renal cell transport mechanisms and their impairment by xenobiotics are often limited by technical difficulties related to renal tubule complexity. Problems include the juxtaposition of multiple tubule segments with different transport functions and severely limited access to the tubular lumen. Some limitations can be overcome by the careful selection of an appropriate aquatic experimental system. Two aquatic models for the vertebrate proximal segment are discussed here. The first is the kidney from certain marine flounder, which offers the following advantages: long-term viability, little tissue of nonproximal origin, and easy tubule isolation. Data are presented to demonstrate how studies with flounder kidney can be used to elucidate cellular mechanisms whereby different classes of toxic pollutants may interact. Results from these experiments indicate that the excretion of certain anionic xenobiotics can be delayed by other anionic xenobiotics that compete for secretory transport sites and by compounds that disrupt cellular ion gradients and energy metabolism needed to drive transport. The second system is the crustacean urinary bladder, a simple, flatsheet epithelium. Bladder morphology and transport physiology closely resemble those of vertebrate proximal segment. Electron micrographs show a brush border membrane at the luminal surface, numerous mitochondria, and an infolded serosal membrane, while in vivo and in vitro transport studies show reabsorption of NaCl, nutrients and water and secretion of organic cations; organic anions are secreted in bladders from some species and reabsorbed in others. Moreover, since bladders can be mounted as flat sheets in flux chambers, studies with this tissue avoid the problems of complex renal tubule geometry and tissue heterogeneity that limit transport studies in proximal tubule. PMID:3297665

  11. Aquatic models for the study of renal transport function and pollutant toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.S.

    1987-04-01

    Studies of renal cell transport mechanisms and their impairment by xenobiotics are often limited by technical difficulties related to renal tubule complexity. Problems include the juxtaposition of multiple tubule segments with different transport functions and severely limited access to the tubular lumen. Some limitations can be overcome by the careful selection of an appropriate aquatic experimental system. Two aquatic models for the vertebrate proximal segment are discussed here. The first is the kidney from certain marine flounder, which offers the following advantages: long-term viability, little tissue of nonproximal origin, and easy tubule isolation. Data are presented to demonstrate how studies with flounder kidney can be used to elucidate cellular mechanisms whereby different classes of toxic pollutants may interact. Results from these experiments indicate that the excretion of certain anionic xenobiotics can be delayed (1) by other anionic xenobiotics that compete for secretory transport sites and (2) by compounds that disrupt cellular ion gradients and energy metabolism needed to drive transport. The second system is the crustacean urinary bladder, a simple, flatsheet epithelium. Bladder morphology and transport physiology closely resemble those of vertebrate proximal segment. Electron micrographs show a brush border membrane at the luminal surface, numerous mitochondria, and an infolded serosal membrane, while in vivo and in vitro transport studies show reabsorption of NaCl, nutrients and water and secretion of organic cations; organic anions are secreted in bladders from some species and reabsorbed in others. Moreover, since bladders can be mounted as flat sheets in flux chambers, studies with this tissue avoid the problems of complex renal tubule geometry and tissue heterogeneity and tissue heterogeneity that limit transport studies in proximal tubule.

  12. Experimental study and modelization of radium transfer in a simplified aquatic ecosystem

    International Nuclear Information System (INIS)

    Radium transfer has been studied in an experimental aquatic ecosystem composed by four trophic levels. Water and sediment are the two abiotic units from which the other compartments could be contamined. Scenedesmus obliquus represents the primary producer. Daphnia magna, Gammarus pulex and Chironomus sp., the first order consumers; Cyprinius carpio, the second order consumer and Salmo gairdneri, the third order one. Each transfer is described by a mathematical equation, based on a theoretical analysis, which represents concentration evolution of each compartment as a function of time. From the experimental data, we suggest a mathematical model in order to simulate radium contamination of the ecosystem. This model takes into account the following parameters: the contamination mode (chronic or acute pollution), the type of ecosystem concerned by the contamination (pond or river), and the season during which the pollution occurred. Results obtained with the model agree with most of field data on contamination level of fish living in the mining complex environment; particularly, they put the emphasize on the trophic way for the fish radiocontamination

  13. A modelling framework for the transport, transformation and biouptake of manufactured nanoparticles in the aquatic environment

    Science.gov (United States)

    Lofts, Stephen; Keller, Virginie; Dumont, Egon; Williams, Richard; Praetorius, Antonia; von der Kammer, Frank

    2016-04-01

    The development of innovative new chemical products is a key aspect of the modern economy, yet society demands that such development is environmentally sustainable. Developing knowledge of how new classes of chemicals behave following release to the environment is key to understanding the hazards that will potentially result. Nanoparticles are a key example of a class of chemicals that have undergone a significant expansion in production and use in recent years and so there is a need to develop tools to predict their potential hazard following their deliberate or incidental release to the environment. Generalising the understanding of the environmental behaviour of manufactured nanoparticles in general is challenging, as they are chemically and physically diverse (e.g. metals, metal oxides, carbon nanotubes, cellulose, quantum dots). Furthermore, nanoparticles may be manufactured with capping agents to modify their desired behaviour in industrial applications; such agents may also influence their environmental behaviour. Also, nanoparticles may become significantly modified from their as-manufactured forms both prior to and after the point of environmental release. Tools for predicting nanoparticle behaviour and hazard need to be able to consider a wide range of release scenarios and aspects of nanoparticle behaviour in the environment (e.g. dissolution, transformation of capping agents, agglomeration and aggregation behaviour), where such behaviours are not shared by all types of nanoparticle. This implies the need for flexible, futureproofed tools capable of being updated to take new understanding of behavioural processes into account as such knowledge emerges. This presentation will introduce the NanoFASE model system, a multimedia modelling framework for the transport, transformation and biouptake of manufactured nanoparticles. The complete system will comprise atmospheric, terrestrial and aquatic compartments to allow holistic simulation of nanoparticles; this

  14. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water....

  15. Bioaccumulation of Aluminium in Hydromacrophytes in Polish Coastal Lakes

    Directory of Open Access Journals (Sweden)

    Senze Magdalena

    2015-03-01

    Full Text Available The research on aluminium content was conducted in water and on aquatic flora of Polish lakes in the central part of the coast. The study included the lakes Sarbsko, Choczewskie, Bia.e, K.odno, D.brze and Salino investigated in the summer of 2013. The examined lakes belong mainly to the direct basin of the Baltic Sea. Samples of aquatic plants and lake waters were collected. In the water samples pH and electrolytic conductivity were measured. The aluminium content was determined both in water and aquatic plants. Submerged hydromacrophyte studies included Myriophyllum alterniflorum L., Potamogeton perfoliatus L. and Ceratophyllum demersum L. Emergent hydromacrophyte studies included Phragmites australis (Cav. Trin. ex Steud., Juncus bulbosus L., Iris pseudacorus L., Eleocharis palustris (L. Roem. % Schult., Phalaris arundinacea L., Carex riparia Curt., Mentha aquatic L., Stratiotes aloides L., Alisma plantago-aquatica L., Glyceria maxima (Hartman Holmb., Sagittaria sagittifolia L., Scirpus lacustris L. and Typha angustifolia L. The purpose of this investigation was the determination of the aluminium content in submerged and emergent hydromacrophytes and also the definition of their bioaccumulative abilities. The average concentration of aluminium in water was 2.68 fęg Al dm.3. The average content of aluminium in plants was 2.8015 mg Al kg.1. The bioaccumulation factor ranged from BCF=19.74 to BCF=16619. On the basis of the analysis of the aluminium content in water and aquatic plants results show that both water and plants were characterized by a moderate level of aluminium. The recorded concentrations indicate a mid-range value and are much lower than those which are quoted for a variety of surface waters in various parts of the world.

  16. A model for the bioaccumulation of (99)Tc in lobsters (Homarus gammarus) from the West Cumbrian coast.

    Science.gov (United States)

    Olsen, Y S; Vives i Batlle, J

    2003-01-01

    A biokinetic model is presented that simulates the uptake and release of (99)Tc by the European lobster (Homarus gammarus). This organism is of significant radioecological interest since lobsters, in contrast to most other organisms, have a high affinity for (99)Tc. The model is designed to represent annually averaged (99)Tc concentrations in lobsters from the Cumbrian coast, where significant levels of (99)Tc have been released under authorisation by the nuclear fuel reprocessing plant at BNFL Sellafield. This paper describes the construction of the model, how it was calibrated using data from published literature, and preliminary results indicating that model output agrees well with the available monitoring data. Given that this model successfully combines laboratory and field data, this research could potentially make a significant contribution to the field, as, to date, it has been difficult to predict and explain concentrations of (99)Tc in lobsters. PMID:12691720

  17. A model for the bioaccumulation of {sup 99}Tc in lobsters (Homarus gammarus) from the West Cumbrian coast

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Y.S.; Vives i Batlle, J. E-mail: jordi.vives@westlakes.ac.uk

    2003-07-01

    A biokinetic model is presented that simulates the uptake and release of {sup 99}Tc by the European lobster (Homarus gammarus). This organism is of significant radioecological interest since lobsters, in contrast to most other organisms, have a high affinity for {sup 99}Tc. The model is designed to represent annually averaged {sup 99}Tc concentrations in lobsters from the Cumbrian coast, where significant levels of {sup 99}Tc have been released under authorisation by the nuclear fuel reprocessing plant at BNFL Sellafield. This paper describes the construction of the model, how it was calibrated using data from published literature, and preliminary results indicating that model output agrees well with the available monitoring data. Given that this model successfully combines laboratory and field data, this research could potentially make a significant contribution to the field, as, to date, it has been difficult to predict and explain concentrations of {sup 99}Tc in lobsters.

  18. Daphnia as a model organism in limnology and aquatic biology: introductory remarks

    Directory of Open Access Journals (Sweden)

    Adam PETRUSEK

    2011-08-01

    Full Text Available Cladocerans of the genus Daphnia are keystone pelagic filter feeders in many temperate ponds and lakes. They have also become popular model organisms in various biological disciplines, from aquatic ecology to biomedical sciences. The crucial features that make these organisms excellent experimental models are their cyclical parthenogenetic life cycle together with easy culturing and handling. Thanks to these characteristics, the number of publications dealing with Daphnia is rapidly growing. The special insert to the Journal of Limnology on Daphnia biology contains contributions that deal directly or indirectly with the reproduction and development of these water fleas, in relation to various ecological factors. These include predator-prey interactions and their impact on morphology, population dynamics, or senescence-related traits, growth of daphnids on a diet consisting of invasively spreading cyanobacteria, and also the impact of extreme floods on a Daphnia population (and particularly on its dormant ephippial egg bank in a reservoir. Here, we discuss these presented works, and point out the potential lines of research that may improve the generalisation of their findings.

  19. Biodynamic modelling of the bioaccumulation of trace metals (Ag, As and Zn) by an infaunal estuarine invertebrate, the clam Scrobicularia plana

    Energy Technology Data Exchange (ETDEWEB)

    Kalman, J., E-mail: judit.kalman@uca.es [Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Smith, B.D. [Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Bury, N.R. [Division of Diabetes and Nutritional Science, King' s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH (United Kingdom); Rainbow, P.S. [Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom)

    2014-09-15

    Highlights: • Biodynamic modelling is used to predict accumulation of Ag, As and Zn in S. plana. • Dissolved and sediment-associated metals contribute to total metal bioaccumulation. • Relative importance varies with water and sediment concentrations and geochemistries. - Abstract: Biodynamic modelling was used to investigate the uptake and accumulation of three trace metals (Ag, As, Zn) by the deposit feeding estuarine bivalve mollusc Scrobicularia plana. Radioactive labelling techniques were used to quantify the rates of trace metal uptake (and subsequent elimination) from water and sediment diet. The uptake rate constant from solution (±SE) was greatest for Ag (3.954 ± 0.375 l g{sup −1} d{sup −1}) followed by As (0.807 ± 0.129 l g{sup −1} d{sup −1}) and Zn (0.103 ± 0.016 l g{sup −1} d{sup −1}). Assimilation efficiencies from ingested sediment were 40.2 ± 1.3% (Ag), 31.7 ± 1.0% (Zn) and 25.3 ± 0.9% (As). Efflux rate constants after exposure to metals in the solution or sediment fell in the range of 0.014–0.060 d{sup −1}. By incorporating these physiological parameters into biodynamic models, our results showed that dissolved metal is the predominant source of accumulated Ag, As and Zn in S. plana, accounting for 66–99%, 50–97% and 52–98% of total accumulation of Ag, As and Zn, respectively, under different field exposure conditions. In general, model-predicted steady state concentrations of Ag, As and Zn matched well with those observed in clams collected in SW England estuaries. Our findings highlight the potential of biodynamic modelling to predict Ag, As and Zn accumulation in S. plana, taking into account specific dissolved and sediment concentrations of the metals at a particular field site, together with local water and sediment geochemistries.

  20. Modelling population-level consequences of chronic external gamma irradiation in aquatic invertebrates under laboratory conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lance, Emilie [Laboratoire de modelisation pour l' expertise environnementale (LM2E) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France); Alonzo, Frederic, E-mail: frederic.alonzo@irsn.fr [Laboratoire d' ecotoxicologie des radionucleides (LECO) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France); Garcia-Sanchez, Laurent [Laboratoire de biogeochimie, biodisponibilite et transferts des radionucleides (L2BT) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France); Beaugelin-Seiller, Karine; Garnier-Laplace, Jacqueline [Laboratoire de modelisation pour l' expertise environnementale (LM2E) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France)

    2012-07-01

    We modelled population-level consequences of chronic external gamma irradiation in aquatic invertebrates under laboratory conditions. We used Leslie matrices to combine life-history characteristics (duration of life stages, survival and fecundity rates) and dose rate-response curves for hatching, survival and reproduction fitted on effect data from the FREDERICA database. Changes in net reproductive rate R{sub 0} (offspring per individual) and asymptotic population growth rate {lambda} (dimensionless) were calculated over a range of dose rates in two marine polychaetes (Neanthes arenaceodentata and Ophryotrocha diadema) and a freshwater gastropod (Physa heterostropha). Sensitivities in R{sub 0} and {lambda} to changes in life-history traits were analysed in each species. Results showed that fecundity has the strongest influence on R{sub 0}. A delay in age at first reproduction is most critical for {lambda} independent of the species. Fast growing species were proportionally more sensitive to changes in individual endpoints than slow growing species. Reduction of 10% in population {lambda} were predicted at dose rates of 6918, 5012 and 74,131 {mu}Gy{center_dot}h{sup -1} in N. arenaceodentata, O. diadema and P. heterostropha respectively, resulting from a combination of strong effects on several individual endpoints in each species. These observations made 10%-reduction in {lambda} a poor criterion for population protection. The lowest significant changes in R{sub 0} and {lambda} were respectively predicted at a same dose rate of 1412 {mu}Gy h{sup -1} in N. arenaceodentata, at 760 and 716 {mu}Gy h{sup -1} in O. diadema and at 12,767 and 13,759 {mu}Gy h{sup -1} in P. heterostropha. These values resulted from a combination of slight but significant changes in several measured endpoints and were lower than effective dose rates calculated for the individual level in O. diadema and P. heterostropha. The relevance of the experimental dataset (external irradiation rather

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

    Science.gov (United States)

    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

  2. Developing Seasonal Spectral Signature Models to Accurately Assess Indicators of Aquatic Health: Malheur NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aquatic health is the number one issue to be addressed in the Malheur National Wildlife Refuge Comprehensive Conservation Plan. Malheur Lake is the number one...

  3. Perturbations to aquatic photosynthesis due to high-energy cosmic ray induced muon flux in the extragalactic shock model

    CERN Document Server

    Rodriguez, Lien; Rodriguez, Oscar

    2013-01-01

    We modify a mathematical model of photosynthesis to quantify the perturbations that high energy muons could make on aquatic primary productivity. Then we apply this in the context of the extragalactic shock model, according to which Earth receives an enhanced dose of high-energy cosmic rays when it is at the galactic north. We obtain considerable reduction in the photosynthesis rates, consistent with potential drops in biodiversity.

  4. Applications of contaminant fate and bioaccumulation models in assessing ecological risks of chemicals: A case study for gasoline hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    MacLeod, Matthew; McKone, Thomas E.; Foster, Karen L.; Maddalena, Randy L.; Parkerton, Thomas F.; Mackay, Don

    2004-02-01

    Mass balance models of chemical fate and transport can be applied in ecological risk assessments for quantitative estimation of concentrations in air, water, soil and sediment. These concentrations can, in turn, be used to estimate organism exposures and ultimately internal tissue concentrations that can be compared to mode-of-action-based critical body residues that correspond to toxic effects. From this comparison, risks to the exposed organism can be evaluated. To illustrate the practical utility of fate models in ecological risk assessments of commercial products, the EQC model and a simple screening level biouptake model including three organisms, (a bird, a mammal and a fish) is applied to gasoline. In this analysis, gasoline is divided into 24 components or ''blocks'' with similar environmental fate properties that are assumed to elicit ecotoxicity via a narcotic mode of action. Results demonstrate that differences in chemical properties and mode of entry into the environment lead to profound differences in the efficiency of transport from emission to target biota. We discuss the implications of these results and insights gained into the regional fate and ecological risks associated with gasoline. This approach is particularly suitable for assessing mixtures of components that have similar modes of action. We conclude that the model-based methodologies presented are widely applicable for screening level ecological risk assessments that support effective chemicals management.

  5. Bioaccumulation and trophic transfer of engineered nanoparticles in aquatic organisms

    DEFF Research Database (Denmark)

    Skjolding, Lars Michael

    Use of engineered nanoparticles (ENPs) (particles with a diameter of 1 to 100nm) is increasing. Engineered NPs are used in a wide variety of consumer product, industrial uses and remediation of pollutants. The increasing use is due to novel physical and chemical properties varying from that of th......Use of engineered nanoparticles (ENPs) (particles with a diameter of 1 to 100nm) is increasing. Engineered NPs are used in a wide variety of consumer product, industrial uses and remediation of pollutants. The increasing use is due to novel physical and chemical properties varying from...... was highlighted to identify artefacts and avoid misinterpretation of results. Furthermore, a general lack of understanding of internalization processes of ENPs after in vivo exposure was identified in the literature in regards to intrinsic properties of ENPs (e.g. particle sizes, coatings and functionalizations...

  6. Development and application of a multimetal multibiotic ligand model for assessing aquatic toxicity of metal mixtures.

    Science.gov (United States)

    Santore, Robert C; Ryan, Adam C

    2015-04-01

    A multimetal, multiple binding site version of the biotic ligand model (mBLM) has been developed for predicting and explaining the bioavailability and toxicity of mixtures of metals to aquatic organisms. The mBLM was constructed by combining information from single-metal BLMs to preserve compatibility between the single-metal and multiple-metal approaches. The toxicities from individual metals were predicted by assuming additivity of the individual responses. Mixture toxicity was predicted based on both dissolved metal and mBLM-normalized bioavailable metal. Comparison of the 2 prediction methods indicates that metal mixtures frequently appear to have greater toxicity than an additive estimation of individual effects on a dissolved metal basis. However, on an mBLM-normalized basis, mixtures of metals appear to be additive or less than additive. This difference results from interactions between metals and ligands in solutions including natural organic matter, processes that are accounted for in the mBLM. As part of the mBLM approach, a technique for considering variability was developed to calculate confidence bounds (called response envelopes) around the central concentration-response relationship. Predictions using the mBLM and response envelope were compared with observed toxicity for a number of invertebrate and fish species. The results show that the mBLM is a useful tool for considering bioavailability when assessing the toxicity of metal mixtures.

  7. Numerical modelling of distribution the discharged heat water from thermal power plant on the aquatic environment

    Science.gov (United States)

    Issakhov, Alibek

    2016-06-01

    The paper presents a mathematical model of distribution the discharged heat water from thermal power plant under various operational capacities on the aquatic environment. It was solved by the Navier-Stokes and temperature equations for an incompressible fluid in a stratified medium were based on the splitting method by physical parameters which approximated by the finite volume method. The numerical solution of the equation system was divided into four stages. At the first step it was assumed that the momentum transfer carried out only by convection and diffusion. While the intermediate velocity field was solved by 5-step Runge-Kutta method. At the second stage, the pressure field was solved by found the intermediate velocity field. Whereas Poisson equation for the pressure field was solved by Jacobi method. The third step assumes that the transfer was carried out only by pressure gradient. Finally the fourth step of the temperature equation was also solved as motion equations, with 5-step Runge-Kutta method. The algorithm was parallelized on high-performance computer. The obtained numerical results of three-dimensional stratified turbulent flow were compared with experimental data. What revealed qualitatively and quantitatively approximately the basic laws of hydrothermal processes occurring in the reservoir-cooler.

  8. PIXE analysis of chromium phytoaccumulation by the aquatic macrophytes Eicchornia crassipes

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza-Quinones, F.R. [Department of Chemical Engineering - Postgraduate Program - NBQ, West Parana State University, Rua da Faculdade, 645, Jardim Santa Maria, 85903-000 Toledo, Parana (Brazil)], E-mail: f.espinoza@terra.com.br; Rizzutto, M.A.; Added, N.; Tabacniks, M.H. [Physics Institute, University of Sao Paulo, Rua do Matao s/n, Travessa R 187, 05508-900 Sao Paulo, SP (Brazil); Modenes, A.N.; Palacio, S.M.; Silva, E.A.; Rossi, F.L.; Martin, N.; Szymanski, N. [Department of Chemical Engineering - Postgraduate Program - NBQ, West Parana State University, Rua da Faculdade, 645, Jardim Santa Maria, 85903-000 Toledo, Parana (Brazil)

    2009-04-15

    The uptake of hexavalent chromium in free living floating aquatic macrophytes Eicchornia crassipes cultivated in non-toxic chromium-doped hydroponic solutions is presented. A Cr-uptake bioaccumulation experiment was carried out using healthy macrophytes grown in a temperature controlled greenhouse. Six samples of nutrient media and plants were collected during the 23 day experiment. Roots and leaves were acid digested with the addition of an internal Gallium standard, for thin film sample preparation and quantitative Cr analysis by PIXE method. The Cr{sup 6+} mass uptake by the macrophytes reached up to 70% of the initial concentration, comparable to former results and literature data. The Cr-uptake data were described using a non-structural first order kinetic model. Due to low cost and high removal efficiency, living aquatic macrophytes E. crassipes are a viable biosorbent in an artificial wetland of a water effluent treatment plant.

  9. PIXE analysis of chromium phytoaccumulation by the aquatic macrophytes Eicchornia crassipes

    International Nuclear Information System (INIS)

    The uptake of hexavalent chromium in free living floating aquatic macrophytes Eicchornia crassipes cultivated in non-toxic chromium-doped hydroponic solutions is presented. A Cr-uptake bioaccumulation experiment was carried out using healthy macrophytes grown in a temperature controlled greenhouse. Six samples of nutrient media and plants were collected during the 23 day experiment. Roots and leaves were acid digested with the addition of an internal Gallium standard, for thin film sample preparation and quantitative Cr analysis by PIXE method. The Cr6+ mass uptake by the macrophytes reached up to 70% of the initial concentration, comparable to former results and literature data. The Cr-uptake data were described using a non-structural first order kinetic model. Due to low cost and high removal efficiency, living aquatic macrophytes E. crassipes are a viable biosorbent in an artificial wetland of a water effluent treatment plant.

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

    Energy Technology Data Exchange (ETDEWEB)

    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 primarily 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.

  11. The development of an aquatic spill model for the White Oak Creek watershed, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.O.

    1996-05-01

    This study develops an aquatic spill model applicable to the White Oak Creek watershed draining the Oak Ridge National Laboratory. Hazardous, toxic, and radioactive chemicals are handled and stored on the laboratory reservation. An accidental spill into the White Oak Creek watershed could contaminate downstream water supplies if insufficient dilution did not occur. White Oak Creek empties into the Clinch River, which flows into the Tennessee River. Both rivers serve as municipal water supplies. The aquatic spill model provides estimates of the dilution at sequential downstream locations along White Oak creek and the Clinch River after an accidental spill of a liquid containing a radioactively decaying constituent. The location of the spill on the laboratory is arbitrary, while hydrologic conditions range from drought to extreme flood are simulated. The aquatic spill model provides quantitative estimates with which to assess water quality downstream from the site of the accidental spill, allowing an informed decision to be made whether to perform mitigating measures so that the integrity of affected water supplies is not jeopardized.

  12. The antihistamine hydroxyzine and Odonata : Bioaccumulation and effects on predator-prey interactions between dragonfly and damselfly larvae

    OpenAIRE

    Bomark, Ellinor

    2014-01-01

    Through wastewater entering aquatic environments, aquatic insects are continuously exposed to pharmaceuticals including neurologically active antihistamines. The antihistamine hydroxyzine has previously been found to lower activity in damselflies and to reach 2000 times the concentration of surrounding water in damselfly tissue. The purpose of this short-term exposure study was to investigate if hydroxyzine also bioaccumulates in dragonflies and if dilute hydroxyzine (362 ± 50, mean ng/l ± SD...

  13. Improving ecological risk assessment of persistent, bioaccumulative, and toxic (PBT) chemicals by using an integrated modeling system - An example assessing chloroparaffins in riverine environments.

    Science.gov (United States)

    Chemical risk assessment (CRA) is primarily carried out at the screening level relying on empirical relationships between chemical properties and tested toxicity effects. Ultimately, risk to aquatic ecosystems is strongly dependent on actual exposure, which depends on chemical pr...

  14. Bioaccumulation of copper and toxic effects on feeding, growth, fecundity and development of pond snail Lymnaea luteola L.

    Science.gov (United States)

    Das, Sangita; Khangarot, B S

    2011-01-15

    We studied the bioaccumulation and the toxic effects of Cu on survival, number of eggs and eggmasses laying, embryo development, growth, and food consumption in an Indian pond snail, Lymnaea luteola L. exposed for 7 weeks. Copper caused loss of chemoreception, locomotion and inhibited food consumption significantly during 7 weeks of exposure. Food consumption in Cu exposed snails significantly decreased and at 56 and 100 μg L(-1), snail stopped feeding activity. Mean number of eggmasses or eggs significantly decreased in Cu concentrations during the 7 week study. The percentage hatching decreased in Cu concentrations but there was more than 95% hatched in control in 10-11 days after spawning. Egg development was completely inhibited at 100 μg L(-1), while abnormal embryonic development observed at 32 and 56 μg L(-1) of Cu. The Cu concentration in tissues increased in Cu treated snails and bioaccumulation factor ranged from 2.3 to 18.7. Snail growth at 5.6 and 10 μg L(-1) was reduced by 6.2% and 16.9%, respectively. The study revealed that snail embryos and adults could be used as in vivo test models for ecotoxicological studies. Findings of present study are helpful for advancing water quality guidelines for protecting aquatic biota.

  15. Bioaccumulation and oxidative stress in Daphnia magna exposed to arsenite and arsenate.

    Science.gov (United States)

    Fan, Wenhong; Ren, Jinqian; Li, Xiaomin; Wei, Chaoyang; Xue, Feng; Zhang, Nan

    2015-11-01

    Arsenic pollution and its toxicity to aquatic organisms have attracted worldwide attention. The bioavailability and toxicity of arsenic are highly related to its speciation. The present study investigated the differences in bioaccumulation and oxidative stress responses in an aquatic organism, Daphnia magna, induced by 2 inorganic arsenic species (As(III) and As(V)). The bioaccumulation of arsenic, Na(+) /K(+) -adenosine triphosphatase (ATPase) activity, reactive oxygen species (ROS) content, total superoxide dismutase (SOD) activity, total antioxidative capability, and malondialdehyde content in D. magna were determined after exposure to 500 µg/L of arsenite and arsenate for 48 h. The results showed that the oxidative stress and antioxidative process in D. magna exposed to arsenite and arsenate could be divided into 3 phases, which were antioxidative response, oxidation inhibition, and antioxidative recovery. In addition, differences in bioaccumulation, Na(+) /K(+) -ATPase activity, and total SOD activity were also found in D. magna exposed to As(III) and As(V). These differences might have been the result of the high affinity of As(III) with sulfhydryl groups in enzymes and the structural similarity of As(V) to phosphate. Therefore, arsenate could be taken up by organisms through phosphate transporters, could substitute for phosphate in biochemical reactions, and could lead to a change in the bioaccumulation of arsenic and activity of enzymes. These characteristics were the possible reasons for the different toxicity mechanisms in the oxidative stress process of arsenite and arsenate. PMID:26084717

  16. Bioaccumulation of ionic titanium and titanium dioxide nanoparticles in zebrafish eleutheroembryos.

    Science.gov (United States)

    López-Serrano Oliver, Ana; Muñoz-Olivas, Riansares; Sanz Landaluze, Jon; Rainieri, Sandra; Cámara, Carmen

    2015-01-01

    The production of titanium dioxide nanoparticles (TiO(2) NPs) for commercial applications has greatly increased over the last years and consequently the potential risk for human health. There is a growing awareness of the need to understand the behavior and influence these nanoparticles exert on the environment. Bioaccumulation serves as a good integrator to assess chemical exposure in aquatic systems and is dependent on factors, such as the exposure routes, diet and the aqueous medium. We analyzed the experimental bioaccumulation capability of ionic titanium and TiO(2) NPs by zebrafish (Danio rerio) eleutheroembryos through bioconcentration factors (BCFs), after 48 or 72 h of exposure. The stability of both chemical forms in an aquatic medium was fully characterized for further bioaccumulation studies. Several stabilizing agents (humic acids, soluble starch, polyethylene glycol, Na(4)P(2)O(7) and Na(2)HPO(4)) for anatase and rutile, the two allotrophs of TiO(2) NPs, were evaluated to check the evolution of the aggregation process. Around 60% of TiO(2) NPs remained disaggregated under simulated environmental conditions with the addition of 50 mg L(-1) of humic acids. However, the presence of eleutheroembryos in the exposure medium increased TiO(2) NPs aggregation in the experimental tests. The BCFs values obtained in all cases were <100, which classifies ionic titanium and TiO(2) NPs as non-bioaccumulative substances, under the REACH regulations.

  17. Contrasting on Hydrocarbon Generation Model and Characteristics of Pyrolysis of Modern Aquatic Plant (Gloeocapsa) vs Marine Animal (Mantis Shrimp)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A hydrocarbon model of the modern aquatic plant Gloeocapsa and the aquatic animal mantis shrimp was found in thermal simulating experiment. The results show that the modern aquatic plant Gloeocapsa is characterized by late generation, late termination and a long duration of oil generation, while the aquatic animal mantis shrimp is characterized by early generation, early termination and a short duration of oil generation. The n-alkanes from Gloeocapsa and mantis shrimp are characterized by peak carbon C15-C17. With increasing thermal simulating temperature, the peak carbon changes from C17 to C15, and the odd-even predominance of n-allanes becomes less clear. The products from Gloeocapsa contain abundant phenanthrene and naphthalene compounds,and even a little retene, while those from mantis shrimp are dominated by naphthalene compounds, and are poor in phenanthrene compounds. Gloeocapsa and mantis shrimp are rich in C27sterane, relatively rich in tricyclic terpones (C1,-C2,) and hopanes (C27-C35), poor in 5α,14β17β sterane, and coprostane does not disappear until 450 ℃. The tricyclic terpanes in Gloeocapsaare characterized by peak carbon C23 and C2>C21, and in mantis shrimp by C21 and C21>C23. The content of pregnanes is very low at low temperature of thermal simulation, while above 360 ℃,high levels of pregnane series compounds and even degraded C2s and C26 steranes occur in thermal simulation products.

  18. Physical model of a floating trash boom to control aquatic weeds at the TVA Widows Creek Fossil Plant

    International Nuclear Information System (INIS)

    This paper reports that the Tennessee Valley Authority (TVA) Widows Creek Fossil plant seasonally encounters adverse accumulations of aquatic weeds at the intakes of the condenser cooling water pumps. To reduce the accumulations, a floating trash boom has been proposed for the intakes. To evaluate the hydraulic feasibility of a boom, a physical model of the intakes has been built at the TVA Engineering Laboratory. The model was used to determine the boom alignment and depth of skimming needed to successfully deflect weeds away from the intakes and provide self-cleaning

  19. The role of exopolymeric substances in the bioaccumulation and toxicity of Ag nanoparticles to algae.

    Science.gov (United States)

    Zhou, Kaijun; Hu, Yi; Zhang, Luqing; Yang, Kun; Lin, Daohui

    2016-01-01

    Exopolymeric substances (EPS) have an important role in bioaccumulation and toxicity of nanoparticles (NPs) to algae, which warrants specific studies. The interaction of EPS with citrate and polyvinyl pyrrolidone (PVP) coated AgNPs (C-AgNPs and P-AgNPs, respectively) and its roles in bioaccumulation and toxicity of the AgNPs to Chlorella pyrenoidosa were investigated. The amino and aromatic carboxylic groups in the EPS were involved in the EPS-AgNP interactions. Compared with Ag(+), C-AgNPs had comparable total bioaccumulation but greater absorption by intact algae with EPS; P-AgNPs had the smallest total bioaccumulation and were mainly adsorbed on algal surfaces. With EPS removed, the total bioaccumulations and surface adsorptions for the three Ag species decreased but the cell internalizations increased; the 96 h half growth inhibition concentrations decreased, indicating EPS alleviated the algal toxicity of Ag. The cell-internalized but not the adsorbed AgNPs could contribute to the nanotoxicity. The EPS could bind both AgNPs and Ag(+), and thus inhibited the cell internalization and the nanotoxicity. However, the EPS-bound Ag on the cell surfaces would migrate along with the algae and be biologically amplified in the aquatic food chains, presenting ecological risks. These results are helpful for understanding the fate and ecological effects of NPs. PMID:27615743

  20. Proceedings of the meeting on computational and experimental studies for modeling of radionuclide migration in complex aquatic ecosystems

    International Nuclear Information System (INIS)

    The Research Group for Environmental Science of JAEA held a meeting on computational and experimental studies for modeling of radionuclide migration in complex aquatic ecosystems during November 16-20 of 2009. The aim was to discuss the relevance of various computational and experimental approaches to that modeling. The meeting was attended by a Swedish researcher, Prof. Dr. Lars Hakanson of Uppsala University. It included a joint talk at the Institute for Environmental Sciences, in addition to a field and facility survey of the JNFL commercial reprocessing plant located in Rokkasho, Aomori. The meeting demonstrated that it is crucial 1) to make a model structure be strictly relevant to the target objectives of a study and 2) to account for inherent fluctuations in target values in nature in a manner of qualitative parameterization. Moreover, it was confirmed that there can be multiple different approaches of modeling (e.g. detailed or simplified) with relevance for the objectives of a study. These discussions should be considered in model integration for complex aquatic ecosystems consisting catchments, rivers, lakes and coastal oceans which can interact with the atmosphere. This report compiles research subjects and lectures presented at the meeting with associated discussions. The 10 of the presented papers indexed individually. (J.P.N.)

  1. Assessment of the consequences of the radioactive contamination of aquatic media and biota. Model testing using Chernobyl data

    International Nuclear Information System (INIS)

    The 'Cooling Pond' scenario was designed to test models for radioactive contamination of aquatic ecosystems, based on data for contamination of different aquatic media and biota due to fallout of radionuclides into the cooling pond of the Chernobyl Nuclear Power Plant. Input data included characteristics of the cooling pond ecosystem (hydrological, hydrochemical, and hydro biological conditions) and estimates of the amounts of 137 Cs in the cooling pond. Predictions were requested in two stages: (1) Calculations of 137 Cs concentrations for comparison against actual measurements, including activities of 137 Cs in the cooling pond water, in layers of sediment, and in fish; (2) Calculations for which actual measurements are not available, including dose and risk estimates for aquatic biota and for humans following hypothetical consumption of contaminated biota. Calculations were performed with the following models: LAKECO (Netherlands), POSOD (USA), LAKEPOND (Romania), WATER (Russia), GIDRO (Russia), and ECOMOD-W (Russia). The total number of scenario calculations was 18. In general, the models tended to overestimate the total doses to fish (as compared to to independent dose estimates made from measured concentrations by the scenario authors) for internal and external exposure, while a number of predictions with different models for the effective dose and risk to humans from fish consumption were in good agreement with independent test estimates. The differences among model predictions were somewhat smaller for the total doses to fish than for the environmental concentrations used in the model testing. The differences among model predictions were very great for the effective doses and risk to humans from fish consumption. This is related to distinct errors in assessments of 137 Cs concentrations in fish. Very few participants obtained good agreement with respect to all criteria of the model testing, i.e., 137 Cs concentrations in the aquatic ecosystem components and

  2. Assessment of the consequences of the radioactive contamination of aquatic media and biota. Model testing using Chernobyl data

    Energy Technology Data Exchange (ETDEWEB)

    Kryshev, I.; Sazykina, T. [SPA Typhoon, Obninsk (Russian Federation); Hoffman, O.; Thiessen, K. [SENES, Oak Ridge, TN (United States)] [and others

    1996-09-01

    The 'Cooling Pond' scenario was designed to test models for radioactive contamination of aquatic ecosystems, based on data for contamination of different aquatic media and biota due to fallout of radionuclides into the cooling pond of the Chernobyl Nuclear Power Plant. Input data included characteristics of the cooling pond ecosystem (hydrological, hydrochemical, and hydro biological conditions) and estimates of the amounts of 137 Cs in the cooling pond. Predictions were requested in two stages: (1) Calculations of 137 Cs concentrations for comparison against actual measurements, including activities of 137 Cs in the cooling pond water, in layers of sediment, and in fish; (2) Calculations for which actual measurements are not available, including dose and risk estimates for aquatic biota and for humans following hypothetical consumption of contaminated biota. Calculations were performed with the following models: LAKECO (Netherlands), POSOD (USA), LAKEPOND (Romania), WATER (Russia), GIDRO (Russia), and ECOMOD-W (Russia). The total number of scenario calculations was 18. In general, the models tended to overestimate the total doses to fish (as compared to to independent dose estimates made from measured concentrations by the scenario authors) for internal and external exposure, while a number of predictions with different models for the effective dose and risk to humans from fish consumption were in good agreement with independent test estimates. The differences among model predictions were somewhat smaller for the total doses to fish than for the environmental concentrations used in the model testing. The differences among model predictions were very great for the effective doses and risk to humans from fish consumption. This is related to distinct errors in assessments of 137 Cs concentrations in fish. Very few participants obtained good agreement with respect to all criteria of the model testing, i.e., 137 Cs concentrations in the aquatic ecosystem

  3. Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals

    Science.gov (United States)

    van den Brink, Nico W.; Arblaster, Jennifer A.; Bowman, Sarah R.; Conder, Jason M.; Elliott, John E.; Johnson, Mark S.; Muir, Derek C.G.; Natal-da-Luz, Tiago; Rattner, Barnett A.; Sample, Bradley E.; Shore, Richard F.

    2016-01-01

    Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To aid scientific and regulatory discourse on the application of terrestrial field data in this manner, this article provides practical recommendations regarding the generation and interpretation of terrestrial field data. Currently, biota-to-soil-accumulation factors (BSAFs), biomagnification factors (BMFs), and bioaccumulation factors (BAFs) are the most suitable bioaccumulation metrics that are applicable to bioaccumulation assessment evaluations and able to be generated from terrestrial field studies with relatively low uncertainty. Biomagnification factors calculated from field-collected samples of terrestrial carnivores and their prey appear to be particularly robust indicators of bioaccumulation potential. The use of stable isotope ratios for quantification of trophic relationships in terrestrial ecosystems needs to be further developed to resolve uncertainties associated with the calculation of terrestrial trophic magnification factors (TMFs). Sampling efforts for terrestrial field studies should strive for efficiency, and advice on optimization of study sample sizes, practical considerations for obtaining samples, selection of tissues for analysis, and data interpretation is provided. Although there is still much to be learned regarding terrestrial bioaccumulation, these recommendations provide some initial guidance to the present application of terrestrial field data as a line of evidence in the assessment of chemical bioaccumulation potential and a resource to inform laboratory and modeling efforts.

  4. Models for transport and fate of carbon, nutrients and point source released radionuclides to an aquatic ecosystem

    International Nuclear Information System (INIS)

    In this report three ecosystem models are described in terms of structure, initial data, and results. All models are dynamic, mass-balanced and describe the transport and fate of elements in an open aquatic ecosystem. The models are based on ecologically sound principles, provide model results with high resolution and transparency, and are constrained by the nutrient dynamics of the ecosystem itself. The processes driving the transport in all the models are both the biological processes such as primary production, consumption, respiration and excretion, and abiotic e.g. water exchange and air-sea exchange. The first model, the CNP-model, describes the distribution and fluxes of carbon and nutrients for the coastal ecosystem off Forsmark. The second model, the C-14 model, is an extension of the CNP-model and describes the transport and distribution of hypothetically released C-14 from the underground repository SFR-1 to the ecosystem above. The third model, the RN-model, is a generic radionuclide flow model that models the transport and distribution of radionuclides other than C-14 hypothetically discharged to the ecosystem. The model also analyses the importance of some radionuclide specific mechanisms for the radionuclide flow. The generic radionuclide model is also based on the CNP-model, but has radionuclide specific mechanisms connected to each compartment

  5. Models for transport and fate of carbon, nutrients and point source released radionuclides to an aquatic ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Kumblad, Linda [Stockholm Univ. (Sweden). Dept. of Systems Ecology; Kautsky, Ulrik [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2004-09-01

    In this report three ecosystem models are described in terms of structure, initial data, and results. All models are dynamic, mass-balanced and describe the transport and fate of elements in an open aquatic ecosystem. The models are based on ecologically sound principles, provide model results with high resolution and transparency, and are constrained by the nutrient dynamics of the ecosystem itself. The processes driving the transport in all the models are both the biological processes such as primary production, consumption, respiration and excretion, and abiotic e.g. water exchange and air-sea exchange. The first model, the CNP-model, describes the distribution and fluxes of carbon and nutrients for the coastal ecosystem off Forsmark. The second model, the C-14 model, is an extension of the CNP-model and describes the transport and distribution of hypothetically released C-14 from the underground repository SFR-1 to the ecosystem above. The third model, the RN-model, is a generic radionuclide flow model that models the transport and distribution of radionuclides other than C-14 hypothetically discharged to the ecosystem. The model also analyses the importance of some radionuclide specific mechanisms for the radionuclide flow. The generic radionuclide model is also based on the CNP-model, but has radionuclide specific mechanisms connected to each compartment.

  6. Aquatic Sediments.

    Science.gov (United States)

    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)

  7. Prediction of the environmental fate and aquatic ecological impact of nitrobenzene in the Songhua River using the modified AQUATOX model

    Institute of Scientific and Technical Information of China (English)

    LEI Bingli; HUANG Shengbiao; QIAO Min; LI Tianyun; WANG Zijian

    2008-01-01

    An accidental discharge of nitrobenzene happened in November 2005 in the Songhuajiang River, China. The AQUATOX model was modified and adapted to simulate the time-dependent nitrobenzene distribution in this multimedia aquatic system and its potential ecological impacts. Nitrobenzene concentrations in flowing water, sediment, and biota were predicted. Based on the initial concentrations of nitrobenzene observed on the field during the accidental discharge, that is, 0.167-1.47 mg/L at different river segments, the predicted water concentrations of nitrobenzene would decrease to 0.02 and 0.002 mg/L after twenty days and one month, respectively. Both model prediction and field observation were in good agreement. The predicted nitrobenzene concentrations in sediments and aquatic organisms would be lower than 0.025 and 0.002 mg/kg, respectively, after two months. Among environmental factors affecting nitrobenzene concentrations in water, inflow water dilution, water temperature, and initial concentration were the most important, by sensitivity analysis. Comparing the perturbed simulation and control simulation, the biomass changes for diatoms and mussel were significantly affected, whereas, no influence on other organisms could be predicted. Therefore the results indicated that nitrobenzene pollution in the Songhuajiang River should have a limited impact on the benthos community.

  8. Nutrient dynamics, transfer and retention along the aquatic continuum from land to ocean: towards integration of ecological and biogeochemical models

    Directory of Open Access Journals (Sweden)

    A. F. Bouwman

    2013-01-01

    Full Text Available In river basins, soils, groundwater, riparian zones and floodplains, streams, rivers, lakes and reservoirs act as successive filters in which the hydrology, ecology and biogeochemical processing are strongly coupled and together act to retain a significant fraction of the nutrients transported. This paper compares existing river ecology concepts with current approaches to describe river biogeochemistry, and assesses the value of these concepts and approaches for understanding the impacts of interacting global change disturbances on river biogeochemistry. Through merging perspectives, concepts, and modeling techniques, we propose integrated model approaches that encompass both aquatic and terrestrial components in heterogeneous landscapes. In this model framework, existing ecological and biogeochemical concepts are extended with a balanced approach for assessing nutrient and sediment delivery, on the one hand, and nutrient in-stream retention on the other hand.

  9. Bioaccumulation of animal adenoviruses in the pink shrimp

    Directory of Open Access Journals (Sweden)

    Roger B. Luz

    2015-09-01

    Full Text Available Adenoviruses are among the most promising viral markers of fecal contamination. They are frequently found in the water, sediment and soil of regions impacted by human activity. Studies of the bioaccumulation of enteric viruses in shrimp are scarce. The cities located in the northern coast of the lake systems in Southern Brazil have high urbanization and intensive farming rates, and poor sewage collection and treatment. One hundred (n = 100 Farfantepenaeus paulensis pink-shrimp specimens and 48 water samples were collected from coastal lagoons between June 2012 and May 2013. Water samples were concentrated and the shrimp, mashed. After DNA extraction, samples were analyzed by real time polymerase chain reaction (qPCR in order to detect and quantify viral genomes. Thirty-five percent of shrimp samples were positive for contamination, predominantly by avian adenoviruses. A total of 91.7% of water samples contained adenoviruses DNA, with the human form being the most frequent. Our results provided evidence of significant bioaccumulation of adenoviruses in shrimp, showing the extent of the impact of fecal pollution on aquatic ecosystems.

  10. Improving plant bioaccumulation science through consistent reporting of experimental data

    DEFF Research Database (Denmark)

    Fantke, Peter; Arnot, Jon A.; Doucette, William J.

    2016-01-01

    Experimental data and models for plant bioaccumulation of organic contaminants play a crucial role for assessing the potential human and ecological risks associated with chemical use. Plants are receptor organisms and direct or indirect vectors for chemical exposures to all other organisms. As new...... experimental data are generated they are used to improve our understanding of plant-chemical interactions that in turn allows for the development of better scientific knowledge and conceptual and predictive models. The interrelationship between experimental data and model development is an ongoing, never......-ending process needed to advance our ability to provide reliable quality information that can be used in various contexts including regulatory risk assessment. However, relatively few standard experimental protocols for generating plant bioaccumulation data are currently available and because of inconsistent...

  11. Mercury bioaccumulation in the Mediterranean

    Directory of Open Access Journals (Sweden)

    Cinnirella S.

    2013-04-01

    Full Text Available This study details mercury pollution within the food chain of the Mediterranean by analysing the most comprehensive mercury dataset available for biota and water measurements. In this study we computed a bioaccumulation factor (BAF for datasets in the existing mercury-related scientific literature, in on-going programs, and in past measurement campaigns. Preliminary results indicate a major lack of information, making the outcome of any assessment very uncertain. Importantly, not all marine eco-regions are (or have ever been covered by measurement campaigns. Most lacking is information associated with the South-Eastern part of the Mediterranean, and in several eco-regions it is still impossible to reconstruct a trophic net, as the required species were not accounted for when mercury measurements were taken. The datasets also have additional temporal sampling problems, as species were often not sampled systematically (but only sporadically during any given sampling period. Moreover, datasets composed of mercury concentrations in water also suffer from similar geographic limitations, as they are concentrated in the North-Western Mediterranean. Despite these concerns, we found a very clear bioaccumulation trend in 1999, the only year where comprehensive information on both methylmercury concentrations in water and biota was available.

  12. Geographic analysis of thermal equilibria: A bioenergetic model for predicting thermal response of aquatic insect communities

    International Nuclear Information System (INIS)

    The thermal regime immediately downstream from bottom release reservoirs is often characterized by reduced diel and seasonal (winter warm/summer cool) conditions. These unusual thermal patterns have often been implicated as a primary factor underlying observed downstream changes in the species composition of aquatic macroinvertebrate communities. The potential mechanisms for selective elimination of benthic species by unusual thermal regimes has been reviewed. Although the effects of temperature on the rate and magnitude of larval growth and development has been included in the list of potential mechanisms, only recently have field studies below dams focused on this interrelationship. This study investigates the overall community structure as well as the seasonal pattern of larval growth and development for several univoltine species of insects in the Delaware River below or near the hypolimnetic discharge of the Cannonsville and Pepeacton dams. These dams, which are located on the West and East branches of the Delaware River, respectively, produce a thermal gradient extending about 70 km downstream

  13. Iron bioaccumulation in mycelium of Pleurotus ostreatus

    Directory of Open Access Journals (Sweden)

    Sandra M. Almeida

    2015-03-01

    Full Text Available Pleurotus ostreatus is able to bioaccumulate several metals in its cell structures; however, there are no reports on its capacity to bioaccumulate iron. The objective of this study was to evaluate cultivation variables to increase iron bioaccumulation in P. ostreatusmycelium. A full factorial design and a central composite design were utilized to evaluate the effect of the following variables: nitrogen and carbon sources, pH and iron concentration in the solid culture medium to produce iron bioaccumulated in mycelial biomass. The maximum production of P. ostreatus mycelial biomass was obtained with yeast extract at 2.96 g of nitrogen L−1 and glucose at 28.45 g L−1. The most important variable to bioaccumulation was the iron concentration in the cultivation medium. Iron concentration at 175 mg L−1 or higher in the culture medium strongly inhibits the mycelial growth. The highest iron concentration in the mycelium was 3500 mg kg−1 produced with iron addition of 300 mg L−1. The highest iron bioaccumulation in the mycelium was obtained in culture medium with 150 mg L−1 of iron. Iron bioaccumulation in P. ostreatus mycelium is a potential alternative to produce non-animal food sources of iron.

  14. Ecological risk assessment for aquatic organisms from over-water uses of glyphosate.

    Science.gov (United States)

    Solomon, Keith R; Thompson, Dean G

    2003-01-01

    Although the herbicide glyphosate is most widely used in agriculture, some is used for the control of emergent aquatic weeds in ditches, wetlands, and margins of water bodies, largely as the formulation Rodeo. This article presents an ecological risk assessment (ERA) of glyphosate and some of the recommended surfactants as used in or near aquatic systems. Glyphosate does not bioaccumulate, biomagnify, or persist in a biologically available form in the environment. Its mechanism of action is specific to plants and it is relatively nontoxic to animals. As a commercial product, glyphosate may be formulated with surfactants that increased efficacy but, in some cases, are more toxic to aquatic organisms than the parent material. For this risk assessment, three model exposure scenarios--static or low-flow systems such as ponds, flowing waters such as streams, and systems subjected to tidal flows such as estuaries--were chosen and application rates from 1 to 8 kg glyphosate/ha were modeled. Additional measured exposure data from several field studies were also used. As acute exposures are most likely to occur, acute toxicity data were used as effect measures for the purposes of risk assessment. Toxicity data were obtained from the literature and characterized using probabilistic techniques. Risk assessments based on estimated and measured concentrations of glyphosate that would result from its use for the control of undesirable plants in wetlands and over-water situations showed that the risk to aquatic organisms is negligible or small at application rates less than 4 kg/ha and only slightly greater at application rates of 8 kg/ha. Less is known about the environmental fate and toxicology of the surfactants commonly used in combination with the Rodeo formulation of glyphosate. The surfactants used for this purpose were judged not to be persistent nor bioaccumulative in the environment. Distributional analysis of measured deposition concentrations of LI 700, suggest that

  15. Metals Bioaccumulation Mechanism in Neem Bark.

    Science.gov (United States)

    Krishnani, Kishore K; Boddu, Veera M; Moon, Deok Hyun; Ghadge, S V; Sarkar, Biplab; Brahmane, M P; Choudhary, K; Kathiravan, V; Meng, Xiaoguang

    2015-09-01

    The aim of this work was to define the bioaccumulation mechanism of metals onto the non-living biomaterial prepared from an extensively available plant bark biomass of neem (Azadirachta indica). Based on maximum ultimate fixation capacities (mmol/g) of the product, metals ions could be arranged as Hg(2+) Neem bark can be used as bioindicators, bioaccumulators and biomonitors while determining environmental pressures. Metal bioaccumulative properties and structural investigation of plant bark has potential in providing quantitative information on the metal contamination in the surrounding environment.

  16. A multiple testing approach for hazard evaluation of complex mixtures in the aquatic environment: the use of diesel oil as a model.

    Science.gov (United States)

    Johnson, B T; Romanenko, V I

    1989-01-01

    Traditional single species toxicity tests and multiple component laboratory-scaled microcosm assays were combined to assess the toxicological hazard of diesel oil, a model complex mixture, to a model aquatic environment. The immediate impact of diesel oil dosed on a freshwater community was studied in a model pond microcosm over 14 days: a 7-day dosage and a 7-day recovery period. A multicomponent laboratory microcosm was designed to monitor the biological effects of diesel oil (1.0 mg litre(-1)) on four components: water, sediment (soil + microbiota), plants (aquatic macrophytes and algae), and animals (zooplanktonic and zoobenthic invertebrates). To determine the sensitivity of each part of the community to diesel oil contamination and how this model community recovered when the oil dissipated, limnological, toxicological, and microbiological variables were considered. Our model revealed these significant occurrences during the spill period: first, a community production and respiration perturbation, characterized in the water column by a decrease in dissolved oxygen and redox potential and a concomitant increase in alkalinity and conductivity; second, marked changes in microbiota of sediments that included bacterial heterotrophic dominance and a high heterotrophic index (0.6), increased bacterial productivity, and the marked increases in numbers of saprophytic bacteria (10 x) and bacterial oil degraders (1000 x); and third, column water acutely toxic (100% mortality) to two model taxa: Selenastrum capricornutum and Daphnia magna. Following the simulated clean-up procedure to remove the oil slick, the recovery period of this freshwater microcosm was characterized by a return to control values. This experimental design emphasized monitoring toxicological responses in aquatic microcosm; hence, we proposed the term 'toxicosm' to describe this approach to aquatic toxicological hazard evaluation. The toxicosm as a valuable toxicological tool for screening aquatic

  17. How TK-TD and population models for aquatic macrophytes could support the risk assessment for plant protection products.

    Science.gov (United States)

    Hommen, Udo; Schmitt, Walter; Heine, Simon; Brock, Theo Cm; Duquesne, Sabine; Manson, Phil; Meregalli, Giovanna; Ochoa-Acuña, Hugo; van Vliet, Peter; Arts, Gertie

    2016-01-01

    This case study of the Society of Environmental Toxicology and Chemistry (SETAC) workshop MODELINK demonstrates the potential use of mechanistic effects models for macrophytes to extrapolate from effects of a plant protection product observed in laboratory tests to effects resulting from dynamic exposure on macrophyte populations in edge-of-field water bodies. A standard European Union (EU) risk assessment for an example herbicide based on macrophyte laboratory tests indicated risks for several exposure scenarios. Three of these scenarios are further analyzed using effect models for 2 aquatic macrophytes, the free-floating standard test species Lemna sp., and the sediment-rooted submerged additional standard test species Myriophyllum spicatum. Both models include a toxicokinetic (TK) part, describing uptake and elimination of the toxicant, a toxicodynamic (TD) part, describing the internal concentration-response function for growth inhibition, and a description of biomass growth as a function of environmental factors to allow simulating seasonal dynamics. The TK-TD models are calibrated and tested using laboratory tests, whereas the growth models were assumed to be fit for purpose based on comparisons of predictions with typical growth patterns observed in the field. For the risk assessment, biomass dynamics are predicted for the control situation and for several exposure levels. Based on specific protection goals for macrophytes, preliminary example decision criteria are suggested for evaluating the model outputs. The models refined the risk indicated by lower tier testing for 2 exposure scenarios, while confirming the risk associated for the third. Uncertainties related to the experimental and the modeling approaches and their application in the risk assessment are discussed. Based on this case study and the assumption that the models prove suitable for risk assessment once fully evaluated, we recommend that 1) ecological scenarios be developed that are also

  18. How TK-TD and population models for aquatic macrophytes could support the risk assessment for plant protection products.

    Science.gov (United States)

    Hommen, Udo; Schmitt, Walter; Heine, Simon; Brock, Theo Cm; Duquesne, Sabine; Manson, Phil; Meregalli, Giovanna; Ochoa-Acuña, Hugo; van Vliet, Peter; Arts, Gertie

    2016-01-01

    This case study of the Society of Environmental Toxicology and Chemistry (SETAC) workshop MODELINK demonstrates the potential use of mechanistic effects models for macrophytes to extrapolate from effects of a plant protection product observed in laboratory tests to effects resulting from dynamic exposure on macrophyte populations in edge-of-field water bodies. A standard European Union (EU) risk assessment for an example herbicide based on macrophyte laboratory tests indicated risks for several exposure scenarios. Three of these scenarios are further analyzed using effect models for 2 aquatic macrophytes, the free-floating standard test species Lemna sp., and the sediment-rooted submerged additional standard test species Myriophyllum spicatum. Both models include a toxicokinetic (TK) part, describing uptake and elimination of the toxicant, a toxicodynamic (TD) part, describing the internal concentration-response function for growth inhibition, and a description of biomass growth as a function of environmental factors to allow simulating seasonal dynamics. The TK-TD models are calibrated and tested using laboratory tests, whereas the growth models were assumed to be fit for purpose based on comparisons of predictions with typical growth patterns observed in the field. For the risk assessment, biomass dynamics are predicted for the control situation and for several exposure levels. Based on specific protection goals for macrophytes, preliminary example decision criteria are suggested for evaluating the model outputs. The models refined the risk indicated by lower tier testing for 2 exposure scenarios, while confirming the risk associated for the third. Uncertainties related to the experimental and the modeling approaches and their application in the risk assessment are discussed. Based on this case study and the assumption that the models prove suitable for risk assessment once fully evaluated, we recommend that 1) ecological scenarios be developed that are also

  19. Bioaccumulation of Triclocarban in Lumbriculus variegatus

    OpenAIRE

    Higgins, Christopher P.; J.Paesani, Zachary; Abbot Chalew, Talia E.; Halden, Rolf U.

    2009-01-01

    The antimicrobial triclocarban (TCC) has been detected in streams and municipal biosolids throughout the United States. In addition, TCC and potential TCC transformation products have been detected at high levels (ppm range) in sediments near major United States cities. Previous work has suggested that TCC is relatively stable in these environments, thereby raising concerns about the potential for bioaccumulation in sediment-dwelling organisms. Bioaccumulation of TCC from sediments was assess...

  20. pH modelling in aquatic systems with time-variable acid-base dissociation constants applied to the turbid, tidal Scheldt estuary

    NARCIS (Netherlands)

    Hofmann, A.F.; Middelburg, J.J.; Soetaert, K.; Meysman, F.J.R.

    2009-01-01

    A new pH modelling approach is presented that explicitly quantifies the influence of biogeochemical processes on proton cycling and pH in an aquatic ecosystem, and which accounts for time variable acid-base dissociation constants. As a case study, the method is applied to investigate proton cycling

  1. Doses from aquatic pathways in CSA-N288.1: deterministic and stochastic predictions compared

    Energy Technology Data Exchange (ETDEWEB)

    Chouhan, S.L.; Davis, P

    2002-04-01

    The conservatism and uncertainty in the Canadian Standards Association (CSA) model for calculating derived release limits (DRLs) for aquatic emissions of radionuclides from nuclear facilities was investigated. The model was run deterministically using the recommended default values for its parameters, and its predictions were compared with the distributed doses obtained by running the model stochastically. Probability density functions (PDFs) for the model parameters for the stochastic runs were constructed using data reported in the literature and results from experimental work done by AECL. The default values recommended for the CSA model for some parameters were found to be lower than the central values of the PDFs in about half of the cases. Doses (ingestion, groundshine and immersion) calculated as the median of 400 stochastic runs were higher than the deterministic doses predicted using the CSA default values of the parameters for more than half (85 out of the 163) of the cases. Thus, the CSA model is not conservative for calculating DRLs for aquatic radionuclide emissions, as it was intended to be. The output of the stochastic runs was used to determine the uncertainty in the CSA model predictions. The uncertainty in the total dose was high, with the 95% confidence interval exceeding an order of magnitude for all radionuclides. A sensitivity study revealed that total ingestion doses to adults predicted by the CSA model are sensitive primarily to water intake rates, bioaccumulation factors for fish and marine biota, dietary intakes of fish and marine biota, the fraction of consumed food arising from contaminated sources, the irrigation rate, occupancy factors and the sediment solid/liquid distribution coefficient. To improve DRL models, further research into aquatic exposure pathways should concentrate on reducing the uncertainty in these parameters. The PDFs given here can he used by other modellers to test and improve their models and to ensure that DRLs

  2. Stream classification of the Apalachicola-Chattahoochee-Flint River System to support modeling of aquatic habitat response to climate change

    Science.gov (United States)

    Elliott, Caroline M.; Jacobson, Robert B.; Freeman, Mary C.

    2014-01-01

    A stream classification and associated datasets were developed for the Apalachicola-Chattahoochee-Flint River Basin to support biological modeling of species response to climate change in the southeastern United States. The U.S. Geological Survey and the Department of the Interior’s National Climate Change and Wildlife Science Center established the Southeast Regional Assessment Project (SERAP) which used downscaled general circulation models to develop landscape-scale assessments of climate change and subsequent effects on land cover, ecosystems, and priority species in the southeastern United States. The SERAP aquatic and hydrologic dynamics modeling efforts involve multiscale watershed hydrology, stream-temperature, and fish-occupancy models, which all are based on the same stream network. Models were developed for the Apalachicola-Chattahoochee-Flint River Basin and subbasins in Alabama, Florida, and Georgia, and for the Upper Roanoke River Basin in Virginia. The stream network was used as the spatial scheme through which information was shared across the various models within SERAP. Because these models operate at different scales, coordinated pair versions of the network were delineated, characterized, and parameterized for coarse- and fine-scale hydrologic and biologic modeling. The stream network used for the SERAP aquatic models was extracted from a 30-meter (m) scale digital elevation model (DEM) using standard topographic analysis of flow accumulation. At the finer scale, reaches were delineated to represent lengths of stream channel with fairly homogenous physical characteristics (mean reach length = 350 m). Every reach in the network is designated with geomorphic attributes including upstream drainage basin area, channel gradient, channel width, valley width, Strahler and Shreve stream order, stream power, and measures of stream confinement. The reach network was aggregated from tributary junction to tributary junction to define segments for the

  3. COMBINING CLIMATE MODEL PREDICTIONS, HYDROLOGICAL MODELING, AND ECOLOGICAL NICHE MODELING ALGORITHMS TO PREDICT THE IMPACTS OF CLIMATE CHANGE ON AQUATIC BIODIVERSITY

    Science.gov (United States)

    The results of this research will provide a broad taxonomic and regional assessment of the impacts of climate change on aquatic species in the United States by producing predictions of current and future habitat quality for aquatic taxa based on multiple climate change scen...

  4. Aquatic Ecology Section

    International Nuclear Information System (INIS)

    Population studies were concerned with predicting long-term consequences of mortality imposed on animal populations by man's activities. These studies consisted of development of a generalized life cycle model and an empirical impingement model for use in impact analysis. Chemical effects studies were conducted on chlorine minimization; fouling by the Asiatic clam; identification of halogenated organics in cooling water; and effects of halogenated organics in cooling systems on aquatic organisms. Ecological transport studies were conducted on availability of sediment-bound 137Cs and 60Co to fish; 137Cs and 60Co in White Oak Lake fish; and chromium levels in fish from a lake chronically contaminated with chromates from cooling towers. Progress is also reported on the following: effects of irradiation on thermal tolerance of mosquito fish; toxicity of nickel to the developing eggs and larvae of carp; accumulation of selected heavy metals associated with fly ash; and environmental monitoring of aquatic ecosystems

  5. The persistence of subsistence: qualitative social-ecological modeling of indigenous aquatic hunting and gathering in tropical Australia

    Directory of Open Access Journals (Sweden)

    Marcus Barber

    2015-03-01

    Full Text Available Subsistence remains critical to indigenous people in settler-colonial states such as Australia, providing key foundations for indigenous identities and for wider state recognition. However, the drivers of contemporary subsistence are rarely fully articulated and analyzed in terms of likely changing conditions. Our interdisciplinary team combined past research experience gained from multiple sites with published literature to create two generalized qualitative models of the socio-cultural and environmental influences on indigenous aquatic subsistence in northern Australia. One model focused on the longer term (inter-year to generational persistence of subsistence at the community scale, the other model on shorter term (day to season drivers of effort by active individuals. The specification of driver definitions and relationships demonstrates the complexities of even generalized and materialist models of contemporary subsistence practices. The qualitative models were analyzed for emergent properties and for responses to plausible changes in key variables: access, habitat degradation, social security availability, and community dysfunction. Positive human community condition is shown to be critical to the long-term persistence of subsistence, but complex interactions of negative and positive drivers shape subsistence effort expended at the individual scale and within shorter time frames. Such models enable motivations, complexities, and the potential management and policy levers of significance to be identified, defined, causally related, and debated. The models can be used to augment future models of human-natural systems, be tested against case-specific field conditions and/or indigenous perspectives, and aid preliminary assessments of the effects on subsistence of changes in social and environmental conditions, including policy settings.

  6. Predicting the aquatic stage sustainability of a restored backwater channel combining in-situ and airborne remotely sensed bathymetric models.

    Science.gov (United States)

    Jérôme, Lejot; Jérémie, Riquier; Hervé, Piégay

    2014-05-01

    As other large river floodplain worldwide, the floodplain of the Rhône has been deeply altered by human activities and infrastructures over the last centuries both in term of structure and functioning. An ambitious restoration plan of selected by-passed reaches has been implemented since 1999, in order to improve their ecological conditions. One of the main action aimed to increase the aquatic areas in floodplain channels (i.e. secondary channels, backwaters, …). In practice, fine and/or coarse alluvium were dredged, either locally or over the entire cut-off channel length. Sometimes the upstream or downstream alluvial plugs were also removed to reconnect the restored feature to the main channel. Such operation aims to restore forms and associated habitats of biotic communities, which are no more created or maintained by the river itself. In this context, assessing the sustainability of such restoration actions is a major issue. In this study, we focus on 1 of the 24 floodplain channels which have been restored along the Rhône River since 1999, the Malourdie channel (Chautagne reach, France). A monitoring of the geomorphologic evolution of the channel has been conducted during a decade to assess the aquatic stage sustainability of this former fully isolated channel, which has been restored as a backwater in 2004. Two main types of measures were performed: (a) water depth and fine sediment thickness were surveyed with an auger every 10 m along the channel centerline in average every year and a half allowing to establish an exponential decay model of terrestrialization rates through time; (b) three airborne campaigns (2006, 2007, 2012) by Ultra Aerial Vehicle (UAV) provided images from which bathymetry were inferred in combination with observed field measures. Coupling field and airborne models allows us to simulate different states of terrestrialization at the scale of the whole restore feature (e.g. 2020/2030/2050). Raw results indicate that terrestrialization

  7. Recent developments of surface complexation models applied to environmental aquatic chemistry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on numerous latest references, the current developments in surface complexation, surface precipitation and the corresponding models (SCMs and SPMs), were reviewed. The contents involved comparison on surface charge composition and layer-structure of solid-solution interface for the classical 1-pK and 2- pK models, In addition, the fundamental concept and relations of the new models, i.e., multi-site complexation (MUSIC) and charge -distribution (CD) MUSIC models were described as well. To avoid misuse or abuse, it must be emphasized that the applicability nd limitation for each model should be considered carefully when selecting the concerned model(s). In addition, some new powerful techniques for surface characterization and analysis applied to model establishment and modification were also briefly introduced.

  8. The use of models in the analysis and management of aquatic and terrestrial animal production systems.

    NARCIS (Netherlands)

    Machiels, M.A.M.; Udo, H.M.J.; Densen, van W.L.T.

    1994-01-01

    Modelling of animal production systems as a whole is mainly used for extensively managed systems, such as fishing and hunting natural animal populations. This type of modelling is widely used in fisheries management, but has as yet found limited application in the modelling of extensive cultivation

  9. Comparing trace metal bioaccumulation characteristics of three freshwater decapods of the genus Macrobrachium

    Energy Technology Data Exchange (ETDEWEB)

    Cresswell, Tom, E-mail: tom.cresswell@ansto.gov.au [Centre for Environmental Contaminants Research, CSIRO Land and Water, New Illawarra Rd, Lucas Heights, 2234, NSW (Australia); School of Applied Sciences, RMIT University, Plenty Road, Bundoora 3083, VIC (Australia); Smith, Ross E.W. [Hydrobiology, Lang Parade, Auchenflower 4066, QLD (Australia); Nugegoda, Dayanthi [School of Applied Sciences, RMIT University, Plenty Road, Bundoora 3083, VIC (Australia); Simpson, Stuart L. [Centre for Environmental Contaminants Research, CSIRO Land and Water, New Illawarra Rd, Lucas Heights, 2234, NSW (Australia)

    2014-07-01

    Highlights: • Exposed three species of prawns of same genus to solid- and dissolved-phase metals. • Cd bioaccumulated from dissolved phase was significantly different between species. • All three species retained >95% of bioaccumulated Cd during the depuration phase. • Bioaccumulation of As, Pb and Zn from solid phase was different between species. • Results highlight variability among species, even under controlled conditions. - Abstract: Potential sources and kinetics of metal bioaccumulation by the three Macrobrachium prawn species M. australiense, M. rosenbergii and M. latidactylus were assessed in laboratory experiments. The prawns were exposed to two scenarios: cadmium in water only; and exposure to metal-rich mine tailings in the same water. The cadmium accumulation from the dissolved exposure during 7 days, followed by depuration in cadmium-free water for 7 days, was compared with predictions from a biokinetic model that had previously been developed for M. australiense. M. australiense and M. latidactylus accumulated significant tissue cadmium during the exposure phase, albeit with different uptake rates. All three species retained >95% of the bioaccumulated cadmium during the depuration phase, indicating very slow efflux rates. Following exposure to tailings, there were significant (p < 0.05) differences in tissue arsenic, cadmium, lead and zinc concentrations among species. Cadmium and zinc concentrations were increased relative to controls for all three species but were not different between treatments (direct/indirect contact with tailings), suggesting these metals were primarily accumulated via the dissolved phase. All species bioaccumulated significantly greater arsenic and lead when in direct contact with mine tailings, demonstrating the importance of an ingestion pathway for these metals. Copper was not bioaccumulated above control concentrations for any species. The differences between the metal accumulation of the three prawns indicated

  10. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    International Nuclear Information System (INIS)

    The aim of the work was to provide supplementary input to the risk assessment of a planned final nuclear waste repository at Forsmark. The main deliverable was a computed water exchange between basins in the Forsmark marine area for the period 6500 BC to 9000 AD - based on the hydrodynamic modelling - to be used as input to the landscape dose model. In addition and what is described in this report, a second deliverable was development and application of high-resolution models for the marine ecosystem and radionuclide processes. The purpose of this deliverable was to illustrate the spatial and temporal variation in important processes and parameters, while constituting a complement to previous modelling approaches and providing supporting information to discussions of the marine ecosystem, parameters and variation (see Chapter 4 and 6).To this end, a hydrodynamic model of high temporal and spatial resolution was constructed and calibrated for the Forsmark area. An ecosystem model was then developed and coupled to the hydrodynamic model. In turn, a detailed radionuclide model was coupled to the ecosystem model to provide detailed predictions of radionuclide transport and accumulation in the coastal ecosystem. The ecosystem and radionuclide models were developed in the equation solver MIKE ECOLab that links seamless to the MIKE3 FM hydrodynamic model. The 'standard' ECOLab ecosystem model was extended with six biological state variables, perennial macroalgae, benthic herbivors, detritus feeders, planktivorus fish and, benthic predators representing the relict isopod Saduria and cod. In contrast to the ecosystem model, the radionuclide model was developed from scratch but building on the structure of the ecosystem model and using the output (process rates linking state variables) from the ecosystem model as input to the radionuclide model. Both the ecosystem model and the radionuclide model were run for several years (5-8 years) to bring state variables into quasi

  11. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes (DHI, Hoersholm (Denmark))

    2010-06-15

    The aim of the work was to provide supplementary input to the risk assessment of a planned final nuclear waste repository at Forsmark. The main deliverable was a computed water exchange between basins in the Forsmark marine area for the period 6500 BC to 9000 AD - based on the hydrodynamic modelling - to be used as input to the landscape dose model. In addition and what is described in this report, a second deliverable was development and application of high-resolution models for the marine ecosystem and radionuclide processes. The purpose of this deliverable was to illustrate the spatial and temporal variation in important processes and parameters, while constituting a complement to previous modelling approaches and providing supporting information to discussions of the marine ecosystem, parameters and variation (see Chapter 4 and 6).To this end, a hydrodynamic model of high temporal and spatial resolution was constructed and calibrated for the Forsmark area. An ecosystem model was then developed and coupled to the hydrodynamic model. In turn, a detailed radionuclide model was coupled to the ecosystem model to provide detailed predictions of radionuclide transport and accumulation in the coastal ecosystem. The ecosystem and radionuclide models were developed in the equation solver MIKE ECOLab that links seamless to the MIKE3 FM hydrodynamic model. The 'standard' ECOLab ecosystem model was extended with six biological state variables, perennial macroalgae, benthic herbivors, detritus feeders, planktivorus fish and, benthic predators representing the relict isopod Saduria and cod. In contrast to the ecosystem model, the radionuclide model was developed from scratch but building on the structure of the ecosystem model and using the output (process rates linking state variables) from the ecosystem model as input to the radionuclide model. Both the ecosystem model and the radionuclide model were run for several years (5-8 years) to bring state variables into

  12. Management of GIS Database and multipurpose customization of computerized models of the contaminated aquatic and terrestrial ecosystems

    International Nuclear Information System (INIS)

    The experience of dealing with geographical and environmental data requests by different codes used for the assessment of radionuclide contamination and for the identifying the optimal remedial strategies for recovering the contaminated ecosystems conducted to the developing of an extended GIS database. This connects to the geographical features an Object Oriented database (OODB) comprising: population, land use, soil type and characteristics, hydrological networks (topologically defined, together with hydraulic parameters). Two problems occurred during the process: - The Price/Quality balance of the data: was solved using data source issued by profile research Institutes and the data acquiring with variable scale having higher resolution in the nuclear risk zones; - The choice between Vector and Raster GIS data types: vector files were preferred, because these can be easily grid transformed. GIS applications where used to extract, by SQL, necessary data for different environmental studies made in some projects: EVANET-HYDRA Customisation of RODOS-Hydro for Danube close to Romanian Cernavoda NPP. Customization of MOIRA: A model-based computerized system for management support for restoring radionuclide contaminated aquatic ecosystems and drainage areas. Using a common GIS database offers the possibility of intercomparison of simulated results of different models and codes

  13. Intra- and inter-laboratory reliability of a cryopreserved trout hepatocyte assay for the prediction of chemical bioaccumulation potential

    Science.gov (United States)

    Cryopreserved trout hepatocytes provide a convenient in vitro system for measuring the intrinsic clearance of xenobiotics. Measured clearance rates can then be extrapolated to the whole animal as a means of improving modeled bioaccumulation predictions. To date, however, the in...

  14. Daphnia as a model organism in limnology and aquatic biology: some aspects of its reproduction and development

    Directory of Open Access Journals (Sweden)

    Adam Petrusek

    2011-08-01

    Full Text Available Invertebrates comprise the overwhelming majority of all animal species - around 95% of described species, not including substantial cryptic variation. As it is an extremely diverse and heterogeneous group, research on various invertebrate taxa often follows parallel trajectories, with little interaction among experts on different groups. To promote sharing of knowledge within as well as across taxa, the International Society of Invertebrate Reproduction and Development (ISIRD was established in 1975 in Calicut, India. Since that time, the ISIRD has organised international conferences at three-year intervals where various aspects of invertebrate biology are presented and discussed, naturally with the focus on reproduction and development. Traditionally, marine invertebrate groups have been well represented at all ISIRD congresses, but freshwater invertebrates have often been relatively overlooked at these meetings. The 12th ISIRD congress took place between August 16 and 20, 2010 in Prague, the Czech Republic. Several different Czech institutions collaborated on the organisation of this meeting. As aquatic invertebrate research has a long tradition in the country, we decided to include a section dedicated to popular model organisms in aquatic ecology and evolutionary biology, the "water fleas", cladocerans of the genus Daphnia. The section entitled "Daphnia and other cladocerans as model organisms" was open to any aspects of cladoceran biology directly or indirectly related to their reproduction or development. Unfortunately, the timing of the Prague congress completely overlapped the triennial congress of the International Society of Theoretical and Applied Limnology (SIL in Cape Town, South Africa. This large meeting in a very attractive setting attracted many cladocerologists from all over the world, including Europe. Therefore, the Daphnia section of the Prague ISIRD meeting remained moderate in size, attracting 13 contributions (eight talks

  15. Multispecies QSAR modeling for predicting the aquatic toxicity of diverse organic chemicals for regulatory toxicology.

    Science.gov (United States)

    Singh, Kunwar P; Gupta, Shikha; Kumar, Anuj; Mohan, Dinesh

    2014-05-19

    The research aims to develop multispecies quantitative structure-activity relationships (QSARs) modeling tools capable of predicting the acute toxicity of diverse chemicals in various Organization for Economic Co-operation and Development (OECD) recommended test species of different trophic levels for regulatory toxicology. Accordingly, the ensemble learning (EL) approach based classification and regression QSAR models, such as decision treeboost (DTB) and decision tree forest (DTF) implementing stochastic gradient boosting and bagging algorithms were developed using the algae (P. subcapitata) experimental toxicity data for chemicals. The EL-QSAR models were successfully applied to predict toxicities of wide groups of chemicals in other test species including algae (S. obliguue), daphnia, fish, and bacteria. Structural diversity of the selected chemicals and those of the end-point toxicity data of five different test species were tested using the Tanimoto similarity index and Kruskal-Wallis (K-W) statistics. Predictive and generalization abilities of the constructed QSAR models were compared using statistical parameters. The developed QSAR models (DTB and DTF) yielded a considerably high classification accuracy in complete data of model building (algae) species (97.82%, 99.01%) and ranged between 92.50%-94.26% and 92.14%-94.12% in four test species, respectively, whereas regression QSAR models (DTB and DTF) rendered high correlation (R(2)) between the measured and model predicted toxicity end-point values and low mean-squared error in model building (algae) species (0.918, 0.15; 0.905, 0.21) and ranged between 0.575 and 0.672, 0.18-0.51 and 0.605-0.689 and 0.20-0.45 in four different test species. The developed QSAR models exhibited good predictive and generalization abilities in different test species of varied trophic levels and can be used for predicting the toxicities of new chemicals for screening and prioritization of chemicals for regulation.

  16. Conceptual model for improving the link between exposure and effects in the aquatic risk assessment of pesticides

    NARCIS (Netherlands)

    Boesten, J.J.T.I.; Köpp, H.; Adriaanse, P.I.; Brock, T.C.M.; Forbes, V.E.

    2007-01-01

    Assessment of risks to aquatic organisms is important in the registration procedures for pesticides in industrialised countries. This risk assessment consists of two parts: (i) assessment of effects to these organisms derived from ecotoxicological experiments (=effect assessment), and (ii) assessmen

  17. Developing Seasonal Spectral Signature Models to Accurately Assess Indicators of Aquatic Health: Algal Succession and Water Quality

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aquatic health is the number one issue to be addressed in the Malheur National Wildlife Refuge Comprehensive Conservation Plan. Malheur Lake is the number one...

  18. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes (DHI, Hoersholm (Denmark))

    2010-06-15

    The aim of the work was to provide supplementary input to the risk assessment of a planned final nuclear waste repository at Forsmark. The main deliverable was a computed water exchange between basins in the Forsmark marine area for the period 6500 BC to 9000 AD - based on the hydrodynamic modelling - to be used as input to the landscape dose model. In addition and what is described in this report, a second deliverable was development and application of high-resolution models for the marine ecosystem and radionuclide processes. The purpose of this deliverable was to illustrate the spatial and temporal variation in important processes and parameters, while constituting a complement to previous modelling approaches and providing supporting information to discussions of the marine ecosystem, parameters and variation (see Chapter 4 and 6).To this end, a hydrodynamic model of high temporal and spatial resolution was constructed and calibrated for the Forsmark area. An ecosystem model was then developed and coupled to the hydrodynamic model. In turn, a detailed radionuclide model was coupled to the ecosystem model to provide detailed predictions of radionuclide transport and accumulation in the coastal ecosystem. The ecosystem and radionuclide models were developed in the equation solver MIKE ECOLab that links seamless to the MIKE3 FM hydrodynamic model. The 'standard' ECOLab ecosystem model was extended with six biological state variables, perennial macroalgae, benthic herbivors, detritus feeders, planktivorus fish and, benthic predators representing the relict isopod Saduria and cod. In contrast to the ecosystem model, the radionuclide model was developed from scratch but building on the structure of the ecosystem model and using the output (process rates linking state variables) from the ecosystem model as input to the radionuclide model. Both the ecosystem model and the radionuclide model were run for several years (5-8 years) to bring state variables into

  19. Modelling indicators of water security, water pollution and aquatic biodiversity in Europe

    OpenAIRE

    Dumont, Egon; Williams, Richard; Keller, Virginie; Voss, Anja; Tattari, Sirkka

    2012-01-01

    The GWAVA (Global Water AVailability Assessment) model for indicating human water security has been extended with a newly developed module for calculating pollutant concentrations. This module is first described and then illustrated by being used to model nitrogen, phosphorus and organic matter concentrations. The module uses solely input variables that are likely to be available for future scenarios, making it possible to apply the module to such scenarios. The module first calculates pollut...

  20. Effect of a levee setback on aquatic resources using two-dimensional flow and bioenergetics models

    Science.gov (United States)

    Black, Robert W.; Czuba, Christiana R.; Magirl, Christopher S.; McCarthy, Sarah; Berge, Hans; Comanor, Kyle

    2016-04-05

    Watershed restoration is the focus of many resource managers and can include a multitude of restoration actions each with specific restoration objectives. For the White River flowing through the cities of Pacific and Sumner, Washington, a levee setback has been proposed to reconnect the river with its historical floodplain to help reduce flood risks, as well as provide increased habitat for federally listed species of salmonids. The study presented here documents the use of a modeling framework that integrates two-dimensional hydraulic modeling with process-based bioenergetics modeling for predicting how changes in flow from reconnecting the river with its floodplain affects invertebrate drift density and the net rate of energy intake of juvenile salmonids. Modeling results were calculated for flows of 25.9 and 49.3 cubic meters per second during the spring, summer, and fall. Predicted hypothetical future mean velocities and depths were significantly lower and more variable when compared to current conditions. The abundance of low energetic cost and positive growth locations for salmonids were predicted to increase significantly in the study reach following floodplain reconnection, particularly during the summer. This modeling framework presents a viable approach for evaluating the potential fisheries benefits of reconnecting a river to its historical floodplain that integrates our understanding of hydraulic, geomorphology, and organismal biology.

  1. Effect of a levee setback on aquatic resources using two-dimensional flow and bioenergetics models

    Science.gov (United States)

    Black, Robert W.; Czuba, Christiana R.; Magirl, Christopher S.; McCarthy, Sarah; Berge, Hans; Comanor, Kyle

    2016-01-01

    Watershed restoration is the focus of many resource managers and can include a multitude of restoration actions each with specific restoration objectives. For the White River flowing through the cities of Pacific and Sumner, Washington, a levee setback has been proposed to reconnect the river with its historical floodplain to help reduce flood risks, as well as provide increased habitat for federally listed species of salmonids. The study presented here documents the use of a modeling framework that integrates two-dimensional hydraulic modeling with process-based bioenergetics modeling for predicting how changes in flow from reconnecting the river with its floodplain affects invertebrate drift density and the net rate of energy intake of juvenile salmonids. Modeling results were calculated for flows of 25.9 and 49.3 cubic meters per second during the spring, summer, and fall. Predicted hypothetical future mean velocities and depths were significantly lower and more variable when compared to current conditions. The abundance of low energetic cost and positive growth locations for salmonids were predicted to increase significantly in the study reach following floodplain reconnection, particularly during the summer. This modeling framework presents a viable approach for evaluating the potential fisheries benefits of reconnecting a river to its historical floodplain that integrates our understanding of hydraulic, geomorphology, and organismal biology.

  2. The AquaDEB project: Physiological flexibility of aquatic animals analysed with a generic dynamic energy budget model (phase II)

    Science.gov (United States)

    Alunno-Bruscia, Marianne; van der Veer, Henk W.; Kooijman, Sebastiaan A. L. M.

    2011-11-01

    This second special issue of the Journal of Sea Research on development and applications of Dynamic Energy Budget (DEB) theory concludes the European Research Project AquaDEB (2007-2011). In this introductory paper we summarise the progress made during the running time of this 5 years' project, present context for the papers in this volume and discuss future directions. The main scientific objectives in AquaDEB were (i) to study and compare the sensitivity of aquatic species (mainly molluscs and fish) to environmental variability within the context of DEB theory for metabolic organisation, and (ii) to evaluate the inter-relationships between different biological levels (individual, population, ecosystem) and temporal scales (life cycle, population dynamics, evolution). AquaDEB phase I focussed on quantifying bio-energetic processes of various aquatic species ( e.g. molluscs, fish, crustaceans, algae) and phase II on: (i) comparing of energetic and physiological strategies among species through the DEB parameter values and identifying the factors responsible for any differences in bioenergetics and physiology; (ii) considering different scenarios of environmental disruption (excess of nutrients, diffuse or massive pollution, exploitation by man, climate change) to forecast effects on growth, reproduction and survival of key species; (iii) scaling up the models for a few species from the individual level up to the level of evolutionary processes. Apart from the three special issues in the Journal of Sea Research — including the DEBIB collaboration (see vol. 65 issue 2), a theme issue on DEB theory appeared in the Philosophical Transactions of the Royal Society B (vol 365, 2010); a large number of publications were produced; the third edition of the DEB book appeared (2010); open-source software was substantially expanded (over 1000 functions); a large open-source systematic collection of ecophysiological data and DEB parameters has been set up; and a series of DEB

  3. An outline of a model-based expert system to identify optimal remedial strategies for restoring contaminated aquatic ecosystems: the project MOIRA

    International Nuclear Information System (INIS)

    The present report describes the fundamental principles of the research programme MOIRA (a model based computerized system for management support to Identify optimal remedial strategies for Restoring radionuclide contaminated Aquatic ecosystems and drainage areas) financed by the EC (European Community) (Contract N F14P-CT96-0036). The interventions to restore radionuclides contaminated aquatic systems may result in detrimental ecological, social and economical effects. Decision makers must carefully evaluate these impacts. The main aim of the MOIRA project is the development of an expert system based on validated models predicting the evolution of the radioactive contamination of fresh water systems following countermeasure applications and their relevant ecological, social and economical impacts. The expert system will help decision makers, that are not necessarily gifted with experience in environmental modeling, to identify optimal remedial strategies for restoring contaminated fresh water systems

  4. Biological factors underlying regularity and chaos in aquatic ecosystems: Simple models of complex dynamics

    Indian Academy of Sciences (India)

    A B Medvinsky; S V Petrovskii; D A Tikhonov; I A Tikhonova; G R Ivanitsky; E Venturino; H Malchow

    2001-03-01

    This work is focused on the processes underlying the dynamics of spatially inhomogeneous plankton communities. We demonstrate that reaction—diffusion mathematical models are an appropriate tool for searching and understanding basic mechanisms of complex spatio-temporal plankton dynamics and fractal properties of planktivorous fish school walks.

  5. Reactive transport in aquatic ecosystems: Rapid model prototyping in the open source software R

    NARCIS (Netherlands)

    Soetaert, K.; Meysman, F.

    2012-01-01

    The concentrations of many natural compounds are altered by chemical and biological transformations, and physical processes such as adsorption and transport. Their fate can be predicted using reactive transport models that describe reaction and advective and dispersive movement of these components i

  6. Ecotoxicity of engineered nanoparticles to aquatic invertebrates: a brief review and recommendations for future toxicity testing

    DEFF Research Database (Denmark)

    Baun, Anders; Hartmann, Nanna Isabella Bloch; Grieger, Khara Deanne;

    2008-01-01

    Daphnia magna as the test organism. To date, the limited number of studies has indicated acute toxicity in the low mgl(-1) range and higher of engineered nanoparticles to aquatic invertebrates, although some indications of chronic toxicity and behavioral changes have also been described at concentrations...... through standardized short-term (lethality) tests with invertebrates as a basis for investigating behaviour and bioavailability of engineered nanoparticles in the aquatic environment. Based on this literature review, we further recommend that research is directed towards invertebrate tests employing long......-term low exposure with chronic endpoints along with more research in bioaccumulation of engineered nanoparticles in aquatic invertebrates....

  7. Wake-based unsteady modeling of the aquatic beetle Dytiscus marginalis

    OpenAIRE

    Whittlesey, Robert W.

    2011-01-01

    Dytiscus marginalis simultaneously uses its hind legs to propel itself through the water. Previous work has suggested that use of synchronized leg motions, such as that used by D. marginalis, allows it to swim with higher hydrodynamic efficiency than similarly sized insects that alternate their legs during swimming. A model is developed based on the generation of vortices in the wake to calculate the relative efficiency of synchronized-leg-swimming kinematics compared to alternating-leg-swimm...

  8. Modeling Microbial Biogeochemistry from Terrestrial to Aquatic Ecosystems Using Trait-Based Approaches

    Science.gov (United States)

    King, E.; Molins, S.; Karaoz, U.; Johnson, J. N.; Bouskill, N.; Hug, L. A.; Thomas, B. C.; Castelle, C. J.; Beller, H. R.; Banfield, J. F.; Steefel, C. I.; Brodie, E.

    2014-12-01

    Currently, there is uncertainty in how climate or land-use-induced changes in hydrology and vegetation will affect subsurface carbon flux, the spatial and temporal distribution of flow and transport, biogeochemical cycling, and microbial metabolic activity. Here we focus on the initial development of a Genome-Enabled Watershed Simulation Capability (GEWaSC), which provides a predictive framework for understanding how genomic information stored in a subsurface microbiome affects biogeochemical watershed functioning, how watershed-scale processes affect microbial function, and how these interactions co-evolve. This multiscale framework builds on a hierarchical approach to multiscale modeling, which considers coupling between defined microscale and macroscale components of a system (e.g., a catchment being defined as macroscale and biogeofacies as microscale). Here, we report our progress in the development of a trait-based modeling approach within a reactive transport framework that simulates coupled guilds of microbes. Guild selection is driven by traits extracted from, and physiological properties inferred from, large-scale assembly of metagenome data. Meta-genomic, -transcriptomic and -proteomic information are also used to complement our existing biogeochemical reaction networks and contributes key reactions where biogeochemical analyses are unequivocal. Our approach models the rate of nutrient uptake and the thermodynamics of coupled electron donors and acceptors for a range of microbial metabolisms including heterotrophs and chemolitho(auto)trophs. Metabolism of exogenous substrates fuels catabolic and anabolic processes, with the proportion of energy used for each based upon dynamic intracellular and environmental conditions. In addition to biomass development, anabolism includes the production of key enzymes, such as nitrogenase for nitrogen fixation or exo-enzymes for the hydrolysis of extracellular polymers. This internal resource partitioning represents a

  9. Identification of model structure for aquatic ecosystems using regionalized sensitivity analysis.

    Science.gov (United States)

    Osidele, O O; Beck, M B

    2001-01-01

    The Regionalized Sensitivity Analysis (RSA) was developed in 1978, for identifying critical unknown processes in poorly defined systems, thus directing the focus of further scientific investigations. Here, we demonstrate its application to model structure identification, by ranking the constituent hypotheses and identifying the critical elements for progressive revision of the model. Our case study is Lake Oglethorpe--a small monomictic impoundment in South-eastern Georgia, USA. Recent studies indicate that the warm temperate regional climate affords an extended growing season--typically from March to October--which promotes bacterial productivity in the lake. The result is a summer food web dominated by microbial processes, in contrast to the conventional phytoplankton-dominated food chains typically observed in the cold temperate lakes of Europe and North America. Starting with a simple phytoplankton-based food web model and a qualitative definition of system behaviour, we use the RSA procedure to establish the critical role of bacteria-mediated decomposition in Lake Oglethorpe, thus justifying the inclusion of microbial processes. Further analysis reveals the importance of size-dependent selective consumption of phytoplankton and bacteria. Finally, we discuss important practical implications of this novel application of the RSA regarding sampling efficiency and statistical robustness.

  10. Baseline for Climate Change: Modeling Watershed Aquatic Biodiversity Relative to Environmental and Anthropogenic Factors

    Energy Technology Data Exchange (ETDEWEB)

    Maurakis, Eugene G

    2010-10-01

    Objectives of the two-year study were to (1) establish baselines for fish and macroinvertebrate community structures in two mid-Atlantic lower Piedmont watersheds (Quantico Creek, a pristine forest watershed; and Cameron Run, an urban watershed, Virginia) that can be used to monitor changes relative to the impacts related to climate change in the future; (2) create mathematical expressions to model fish species richness and diversity, and macroinvertebrate taxa and macroinvertebrate functional feeding group taxa richness and diversity that can serve as a baseline for future comparisons in these and other watersheds in the mid-Atlantic region; and (3) heighten people’s awareness, knowledge and understanding of climate change and impacts on watersheds in a laboratory experience and interactive exhibits, through internship opportunities for undergraduate and graduate students, a week-long teacher workshop, and a website about climate change and watersheds. Mathematical expressions modeled fish and macroinvertebrate richness and diversity accurately well during most of the six thermal seasons where sample sizes were robust. Additionally, hydrologic models provide the basis for estimating flows under varying meteorological conditions and landscape changes. Continuations of long-term studies are requisite for accurately teasing local human influences (e.g. urbanization and watershed alteration) from global anthropogenic impacts (e.g. climate change) on watersheds. Effective and skillful translations (e.g. annual potential exposure of 750,000 people to our inquiry-based laboratory activities and interactive exhibits in Virginia) of results of scientific investigations are valuable ways of communicating information to the general public to enhance their understanding of climate change and its effects in watersheds.

  11. Two dose-estimation models CSA-N288.1 and Nureg 1.109, 1.113 - compared for chronic aquatic releases from nuclear facilities

    CERN Document Server

    Sheppard, S C; Peterson, S R

    2000-01-01

    Both the Canadian Standards Association (CSA) and the United States Nuclear Regulatory Commission (US-NRC) have published guidelines for the calculation of doses to the public due to emissions from nuclear facilities. In the sale of CANDU reactors overseas, either of these guidelines may be used as part of the approval process in the recipient country. This study compares the aquatic exposure pathways described in the guidelines. These include direct consumption of contaminated water and food, and exposure to contaminated sediments. The CSA and US-NRC guidelines for estimating dilution of aquatic emissions are of a general nature and the choice of model used to quantify dilution is left to the user. The models prescribed for the different exposure pathways by these two regulatory guides are similar in many attributes. Many of the recommended parameter values are identical and many of the formulations are either identical, or become identical under general conditions. However, despite these similarities, there...

  12. A genetically explicit model of speciation by sensory drive within a continuous population in aquatic environments

    Directory of Open Access Journals (Sweden)

    Seehausen Ole

    2007-06-01

    Full Text Available Abstract Background The sensory drive hypothesis predicts that divergent sensory adaptation in different habitats may lead to premating isolation upon secondary contact of populations. Speciation by sensory drive has traditionally been treated as a special case of speciation as a byproduct of adaptation to divergent environments in geographically isolated populations. However, if habitats are heterogeneous, local adaptation in the sensory systems may cause the emergence of reproductively isolated species from a single unstructured population. In polychromatic fishes, visual sensitivity might become adapted to local ambient light regimes and the sensitivity might influence female preferences for male nuptial color. In this paper, we investigate the possibility of speciation by sensory drive as a byproduct of divergent visual adaptation within a single initially unstructured population. We use models based on explicit genetic mechanisms for color vision and nuptial coloration. Results We show that in simulations in which the adaptive evolution of visual pigments and color perception are explicitly modeled, sensory drive can promote speciation along a short selection gradient within a continuous habitat and population. We assumed that color perception evolves to adapt to the modal light environment that individuals experience and that females prefer to mate with males whose nuptial color they are most sensitive to. In our simulations color perception depends on the absorption spectra of an individual's visual pigments. Speciation occurred most frequently when the steepness of the environmental light gradient was intermediate and dispersal distance of offspring was relatively small. In addition, our results predict that mutations that cause large shifts in the wavelength of peak absorption promote speciation, whereas we did not observe speciation when peak absorption evolved by stepwise mutations with small effect. Conclusion The results suggest

  13. Hungry Horse mitigation: Aquatic modeling of the selective withdrawal system -- Hungry Horse Dam, Montana

    International Nuclear Information System (INIS)

    Hungry Horse Dam presently releases frigid water from the bottom of the reservoir all year long. Cold water effects insect production and fish growth downstream. Rapid temperature changes of up to 8.3 C (14 F) have been measured in the Flathead River downstream of the South Fork confluence, controlled by dam discharges. Thermal effects from Hungry Horse Dam are detectable for over 64 Km downstream to Flathead Lake. The installation of a selective withdrawal structure on each of the dam's discharge penstocks was determined to be the most cost-effective means to provide constant, permanent temperature control without impacting power production and flexibility in dam operation. The thermal model presented herein revealed that fish growth potential in the river would increase two to five times through selective withdrawal, temperature control. Temperature control is possible over the entire range of turbine discharge capacity, with very little effect on power production. Findings indicate that angling would improve through higher catch rates and larger fish. Temperature control will solve the most serious impact to river health. However, flow fluctuations will continue to effect insect production and usable fishery habitat in the Flathead River. A natural thermal regime combined with moderated flow fluctuation would further enhance riverine food production, trout growth and recreation potential

  14. Bioaccumulation of 137Cs by culture collection strains of bacteria and fungi

    International Nuclear Information System (INIS)

    Soil decontamination of soil contaminated by low-level activities of radionuclides, mainly by caesium-137, which come from accidental releases by maintenance of nuclear devices and by liquid wastes reprocessing, is long-term and expensive technology. Knowledge of the causations, which control the processes of bioaccumulation of radionuclides, is a necessary condition for critical assessment and successful utilization of processes of bioremediation in situ in practise. The authors present the experimentally gained quantitative values of bioaccumulation of caesium-137 from water solutions by micro organism cultures of Rhodotorula aurantiaca CCY 20-9-1, Sacharomyces cerevisiae, Rhodococcus rhodochrous ATCC 15906, Streptomyces sp. DX-IX, Coriolus versicolor CCWDF-14 and Rhizopus sp. R-18. Intensively growing cultures reach the highest values of bioaccumulation; the cultures in non-growing phase reach several orders lower values. From researched micro organisms the highest values of bioaccumulation of Cs+ 5.1 pmol/g (wet weight) at initial concentration of Cs+ in solution co = 1 nmol/l (without carrier) and 29.2 μmol/g (wet weight) at co = 6 mmol/l Cs+ (adding of carrier CsCl) were found out at growing culture S. cerevisiae as model of eukaryotic cell after an achievement of maximal stationary grow phase. Acquired information refer to the possible role of soil micro organisms at bioaccumulation of 137Cs in contaminated soils and their potential utilization in lowering of radioactive contamination of environment (authors)

  15. Bioaccumulation of Arsenic by Fungi

    Directory of Open Access Journals (Sweden)

    Ademola O. Adeyemi

    2009-01-01

    Full Text Available Problem statement: Arsenic is a known toxic element and its presence and toxicity in nature is a worldwide environmental problem. The use of microorganisms in bioremediation is a potential method to reduce as concentration in contaminated areas. Approach: In order to explore the possible bioremediation of this element, three filamentous fungi-Aspergillus niger, Serpula himantioides and Trametes versicolor were investigated for their potential abilities to accumulate (and possibly solubilize arsenic from an agar environment consisting of non buffered mineral salts media amended with 0.2, 0.4, 0.6 and 0.8% (w/v arsenopyrite (FeAsS. Growth rates, dry weights, arsenic accumulation and oxalate production by the fungi as well as the pH of the growth media were all assessed during this study. Results: There was no visible solubilization of FeAsS particles underneath any of the growing fungal colonies or elsewhere in the respective agar plates. No specific patterns of growth changes were observed from the growth ratios of the fungi on agar amended with different amounts of FeAsS although growth of all fungi was stimulated by the incorporation of varying amounts of FeAsS into the agar with the exception of A. niger on 0.4% (w/v amended agar and T. versicolor on 0.8% (w/v amended agar. The amounts of dry weights obtained for all three fungi also did not follow any specific patterns with different amounts of FeAsS and the quantities obtained were in the order A. niger > S. himantioides > T. versicolor. All fungi accumulated as in their biomasses with all amounts of FeAsS although to varying levels and T. versicolor was the most effective with all amounts of FeAsS while A. niger was the least effective. Conclusion: The accumulation of arsenic in the biomasses of the test fungi as shown in this study may suggested a role for fungi through their bioaccumulating capabilities as agents in the possible bioremediation of arsenic contaminated environments.

  16. Using Remotely Sensed Data and Hydrologic Models to Evaluate the Effects of Climate Change on Shallow Aquatic Ecosystems in the Mobile Bay, AL Estuary

    Science.gov (United States)

    Estes, M. G.; Al-Hamdan, M. Z.; Thom, R.; Judd, C.; Woodruff, D.; Ellis, J. T.; Quattrochi, D.; Swann, R.

    2012-01-01

    Coastal systems in the northern Gulf of Mexico, including the Mobile Bay, AL estuary, are subject to increasing pressure from a variety of activities including climate change. Climate changes have a direct effect on the discharge of rivers that drain into Mobile Bay and adjacent coastal water bodies. The outflows change water quality (temperature, salinity, and sediment concentrations) in the shallow aquatic areas and affect ecosystem functioning. Mobile Bay is a vital ecosystem that provides habitat for many species of fauna and flora. Historically, submerged aquatic vegetation (SAV) and seagrasses were found in this area of the northern Gulf of Mexico; however the extent of vegetation has significantly decreased over the last 60 years. The objectives of this research are to determine: how climate changes affect runoff and water quality in the estuary and how these changes will affect habitat suitability for SAV and seagrasses. Our approach is to use watershed and hydrodynamic modeling to evaluate the impact of climate change on shallow water aquatic ecosystems in Mobile Bay and adjacent coastal areas. Remotely sensed Landsat data were used for current land cover land use (LCLU) model input and the data provided by Intergovernmental Panel on Climate Change (IPCC) of the future changes in temperature, precipitation, and sea level rise were used to create the climate scenarios for the 2025 and 2050 model simulations. Project results are being shared with Gulf coast stakeholders through the Gulf of Mexico Data Atlas to benefit coastal policy and climate change adaptation strategies.

  17. Metal mixture toxicity to aquatic biota in laboratory experiments: Application of the WHAM-F{sub TOX} model

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E., E-mail: et@ceh.ac.uk; Lofts, S.

    2013-10-15

    Highlights: •Metal accumulation by living organisms is successfully simulated with WHAM. •Modelled organism-bound metal provides a measure of toxic exposure. •The toxic potency of individual bound metals is quantified by fitting toxicity data. •Eleven laboratory mixture toxicity data sets were parameterised. •Relatively little variability amongst individual test organisms is indicated. -- Abstract: The WHAM-F{sub TOX} model describes the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (F{sub TOX}), a linear combination of the products of organism-bound cation and a toxic potency coefficient (α{sub i}) for each cation. Organism-bound, metabolically-active, cation is quantified by the proxy variable, amount bound by humic acid (HA), as predicted by the WHAM chemical speciation model. We compared published measured accumulations of metals by living organisms (bacteria, algae, invertebrates) in different solutions, with WHAM predictions of metal binding to humic acid in the same solutions. After adjustment for differences in binding site density, the predictions were in reasonable line with observations (for logarithmic variables, r{sup 2} = 0.89, root mean squared deviation = 0.44), supporting the use of HA binding as a proxy. Calculated loadings of H{sup +}, Al, Cu, Zn, Cd, Pb and UO{sub 2} were used to fit observed toxic effects in 11 published mixture toxicity experiments involving bacteria, macrophytes, invertebrates and fish. Overall, WHAM-F{sub TOX} gave slightly better fits than a conventional additive model based on solution concentrations. From the derived values of α{sub i}, the toxicity of bound cations can tentatively be ranked in the order: H < Al < (Zn–Cu–Pb–UO{sub 2}) < Cd. The WHAM-F{sub TOX} analysis indicates much narrower ranges of differences amongst individual organisms in metal toxicity tests than was previously thought. The model potentially provides a means to

  18. The selection of a model microalgal species as biomaterial for a novel aquatic phytotoxicity assay

    Energy Technology Data Exchange (ETDEWEB)

    Bengtson Nash, S.M. [National Research Centre for Environmental Toxicology, University of Queensland, Brisbane QLD 4108 (Australia)]. E-mail: s.nash@uq.edu.au; Quayle, P.A. [National Research Centre for Environmental Toxicology, University of Queensland, Brisbane QLD 4108 (Australia); Schreiber, U. [Lehrstuhl Botanik I, Julius-von-Sachs-Institut fuer Biowissenschaften, Universitaet Wuerzburg, D-97082 Wuerzburg (Germany); Mueller, J.F. [National Research Centre for Environmental Toxicology, University of Queensland, Brisbane QLD 4108 (Australia)

    2005-05-15

    A phytotoxicity assay based on the ToxY-PAM dual-channel yield analyser has been developed and successfully incorporated into field assessments for the detection of phytotoxicants in water. As a means of further exploring the scope of the assay application and of selecting a model biomaterial to complement the instrument design, nine algal species were exposed to four chemical substances deemed of priority for water quality monitoring purposes (chlorpyrifos, copper, diuron and nonylphenol ethoxylate). Inter-species differences in sensitivity to the four toxicants varied by a factor of 1.9-100. Measurements of photosystem-II quantum yield using these nine single-celled microalgae as biomaterial corroborated previous studies which have shown that the ToxY-PAM dual-channel yield analyser is a highly sensitive method for the detection of PS-II impacting herbicides. Besides Phaeodactylum tricornutum, the previously applied biomaterial, three other species consistently performed well (Nitzschia closterium, Chlorella vulgaris and Dunaliella tertiolecta) and will be used in further test optimisation experiments. In addition to sensitivity, response time was evaluated and revealed a high degree of variation between species and toxicants. While most species displayed relatively weak and slow responses to copper, C. vulgaris demonstrated an IC{sub 10} of 51 {mu}g L{sup -1}, with maximum response measured within 25 minutes and inhibition being accompanied by a large decrease in fluorescence yield. The potential for this C. vulgaris-based bioassay to be used for the detection of copper is discussed. There was no evidence that the standard ToxY-PAM protocol, using these unicellular algae species, could be used for the detection of chlorpyrifos or nonylphenol ethoxylate at environmentally relevant levels.

  19. Modelling the winter distribution of a rare and endangered migrant, the Aquatic Warbler Acrocephalus paludicola

    DEFF Research Database (Denmark)

    Walther, Bruno A; Schäffer, Norbert; van Niekerk, Adriaan;

    2007-01-01

    The Aquatic Warbler Acrocephalus paludicola is one of the most threatened Western Palearctic passerine species, classified as globally Vulnerable. With its breeding grounds relatively secure, a clear need remains for the monitoring and protection of the migration and wintering grounds of this rare...... and endangered migrant. Recent research has shown that the Aquatic Warbler migrates through northwest Africa in autumn and spring. The wintering grounds are apparently limited to wetlands of sub-Saharan West Africa, with records from only about 20 localities in Mauritania, Mali, Senegal and Ghana. Given the lack...

  20. Assessment of mechanisms of metal-induced reproductive toxicity in aquatic species as a biomarker of exposure

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.; George, W.; Preslan, J. [and others

    1996-05-02

    This project discusses the following studies: identification and quantitation of heavy metals and petroleum products present in Bayou Trepagnier relative to control sites; assessment of the uptake and bioaccumulation of metals and organic contaminants of interest in aquatic species; establishment and use of polarographic methods for use in metal speciation studies to identify specific chemical forms present in sediments, waters and organism; and evaluation of contaminants on reproductive function of aquatic species as potential biomarkers of exposure. 14 refs.

  1. Bioaccumulation of Zn and Ag Nanoparticles in the Earthworms (Eisenia fetida)

    Science.gov (United States)

    Ha, Lee Seung; Sung-Dae, Kim; Yi, Yang Song; Byeong-Gweon, Lee

    2014-05-01

    Many studies are carried out to evaluate environmental effects of engineered nanoparticles (ENPs). Most of the previous studies primarily focused on the effects of nanoparticles into the aquatic environment and human. Model studies predict that ENPs released into environment would transferred primarily to the soil of the terrestrial environment. Despite this prediction, biogeochemical behavior of ENPs in soil environment as well as bioavailability of ENPs to soil-dwelling organisms such as earthworm, springtail, isopod and nematodes are poorly understood. The main goal of this study was to compare the bioaccumulation factor (BAFs) and subcellular partitioning of nanoparticles in the soil-dwelling earthworm (Eisenia fetida) from ENP (ZnO and Ag nanoparticles) or ionic metal (Zn2+, Ag+) contaminated soil. And the sequential extraction was also used to determine the mobility of metals in soil which could be used as to predict bioavailability and compare that with bioaccumulation factor. The radiotracer method was employed to trace the transfer of ENPs and ionic metal among different environmental media and animals. Radiolabeled 65ZnO, 110mAgNPs coated with PVP or citrate were synthesized in the laboratory and their chemical and biological behavior was compared to ionic 65Zn and 110mAg. The BAFs of Zn and Ag in the earthworms were determined after animals exposed to the contaminated soils. After the 7 days of elimination phase, subcellular partitioning of metals were also obtained. BAF for ZnO(0.06) was 31 times lower than that for Zn ion (1.86), suggesting that ZnO was less bioavailable than its ionic form from contaminated soil. On the other hands, BAFs for AgNPs coated with PVP (0.12) or with citrate (0.11) were comparable to those for Ag ion (0.17), indicating that Ag from contaminated soil was bioavailable in a similar rate regardless of chemical forms. The subcellular partitioning results showed that bioaccumulated Zn from Zn ion and ZnO contaminated soil were

  2. Metals bioaccumulation mechanism in neem bark

    Science.gov (United States)

    The aim of this work was to define the bioaccumulation mechanism of metals onto the non-living biomaterial prepared from an extensively available plant bark biomass of neem (Azadirachta indica). Based on maximum ultimate fixation capacities (mmol/g) of the product, metals ions could be arranged as H...

  3. Studies on the toxicity of an aqueous suspension of C60 nanoparticles using a bacterium (gen. Bacillus) and an aquatic plant (Lemna gibba) as in vitro model systems.

    Science.gov (United States)

    Santos, Sandra M A; Dinis, Augusto M; Rodrigues, David M F; Peixoto, Francisco; Videira, Romeu A; Jurado, Amália S

    2013-10-15

    The increasing use of C60 nanoparticles and the diversity of their applications in industry and medicine has led to their production in a large scale. C60 release into wastewaters and the possible accumulation in the environment has raised concerns about their ecotoxicological impact. In the present study, an aqueous suspension of C60 nanoparticles was prepared and its potential toxicity studied in laboratory, using a bacterium (Bacillus stearothermophilus) and an aquatic plant (Lemna gibba) as model systems. C60 nanoparticles inhibited the growth of L. gibba, in contrast to that of the bacterium. Consistently, the ultrastructure and respiratory activity of bacterial cells were not affected by C60, but the contents of chlorophylls a and b and chloroplast oxygen production decreased considerably in L. gibba. Altogether, our results suggest that C60 aqueous dispersions must be viewed as an environmental pollutant, potentially endangering the equilibrium of aquatic ecosystems. PMID:24084257

  4. UV filters bioaccumulation in fish from Iberian river basins

    Energy Technology Data Exchange (ETDEWEB)

    Gago-Ferrero, Pablo [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens (Greece); Díaz-Cruz, M. Silvia, E-mail: sdcqam@cid.csic.es [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Barceló, Damià [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Catalan Institute for Water Research (ICRA), Parc Científic i Tecnològic de la Universitat de Girona, C/ Emili Grahit, 101 Edifici H2O, E-17003 Girona (Spain)

    2015-06-15

    The occurrence of eight organic UV filters (UV-Fs) was assessed in fish from four Iberian river basins. This group of compounds is extensively used in cosmetic products and other industrial goods to avoid the damaging effects of UV radiation, and has been found to be ubiquitous contaminants in the aquatic ecosystem. In particular, fish are considered by the scientific community to be the most feasible organism for contamination monitoring in aquatic ecosystems. Despite that, studies on the bioaccumulation of UV-F are scarce. In this study fish samples from four Iberian river basins under high anthropogenic pressure were analysed by liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4MBC) and octocrylene (OC) were the predominant pollutants in the fish samples, with concentrations in the range of ng/g dry weight (d.w.). The results indicated that most polluted area corresponded to Guadalquivir River basin, where maximum concentrations were found for EHMC (241.7 ng/g d.w.). Sediments from this river basin were also analysed. Lower values were observed in relation to fish for OC and EHMC, ranging from below the limits of detection to 23 ng/g d.w. Accumulation levels of UV-F in the fish were used to calculate biota-sediment accumulation factors (BSAFs). These values were always below 1, in the range of 0.04–0.3, indicating that the target UV-Fs are excreted by fish only to some extent. The fact that the highest concentrations were determined in predators suggests that biomagnification of UV-F may take place along the freshwater food web. - Highlights: • First evidence of UV filters in fish from Iberian rivers • Biota-sediment accumulation factors (BSAFs) were always below 1. • Predator species presented higher UV-F concentrations suggesting trophic magnification.

  5. UV filters bioaccumulation in fish from Iberian river basins

    International Nuclear Information System (INIS)

    The occurrence of eight organic UV filters (UV-Fs) was assessed in fish from four Iberian river basins. This group of compounds is extensively used in cosmetic products and other industrial goods to avoid the damaging effects of UV radiation, and has been found to be ubiquitous contaminants in the aquatic ecosystem. In particular, fish are considered by the scientific community to be the most feasible organism for contamination monitoring in aquatic ecosystems. Despite that, studies on the bioaccumulation of UV-F are scarce. In this study fish samples from four Iberian river basins under high anthropogenic pressure were analysed by liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4MBC) and octocrylene (OC) were the predominant pollutants in the fish samples, with concentrations in the range of ng/g dry weight (d.w.). The results indicated that most polluted area corresponded to Guadalquivir River basin, where maximum concentrations were found for EHMC (241.7 ng/g d.w.). Sediments from this river basin were also analysed. Lower values were observed in relation to fish for OC and EHMC, ranging from below the limits of detection to 23 ng/g d.w. Accumulation levels of UV-F in the fish were used to calculate biota-sediment accumulation factors (BSAFs). These values were always below 1, in the range of 0.04–0.3, indicating that the target UV-Fs are excreted by fish only to some extent. The fact that the highest concentrations were determined in predators suggests that biomagnification of UV-F may take place along the freshwater food web. - Highlights: • First evidence of UV filters in fish from Iberian rivers • Biota-sediment accumulation factors (BSAFs) were always below 1. • Predator species presented higher UV-F concentrations suggesting trophic magnification

  6. Numerical Model of Channel and Aquatic Habitat Response to Sediment Pulses in Mountain Rivers of Central Idaho

    Science.gov (United States)

    Lewicki, M.; Buffington, J. M.; Thurow, R. F.; Isaak, D. J.

    2006-12-01

    Mountain rivers in central Idaho receive pulsed sediment inputs from a variety of mass wasting processes (side-slope landslides, rockfalls, and tributary debris flows). Tributary debris flows and hyperconcentrated flows are particularly common due to winter "rain-on-snow" events and summer thunderstorms, the effects of which are amplified by frequent wildfire and resultant changes in vegetation, soil characteristics, and basin hydrology. Tributary confluences in the study area are commonly characterized by debris fans built by these repeated sediment pulses, providing long-term controls on channel slope, hydraulics and sediment transport capacity in the mainstem channel network. These long-term impacts are magnified during debris-flow events, which deliver additional sediment and wood debris to the fan and may block the mainstem river. These changes in physical conditions also influence local and downstream habitat for aquatic species, and can impact local human infrastructure (roads, bridges). Here, we conduct numerical simulations using a modified version of Cui's [2005] network routing model to examine bedload transport and debris-fan evolution in medium- sized watersheds (65-570 km2) of south-central Idaho. We test and calibrate the model using data from a series of postfire debris-flow events that occurred from 2003-4. We investigate model sensitivity to different controlling factors (location of the pulse within the stream network, volume of the pulse, and size distribution of the input material). We predict that on decadal time scales, sediment pulses cause a local coarsening of the channel bed in the vicinity of the sediment input, and a wave of downstream fining over several kilometers of the river (as long as the pulse material is not coarser than the stream bed itself). The grain-size distribution of the pulse influences its rate of erosion, the rate and magnitude of downstream fining, and the time required for system recovery. The effects of textural

  7. The biotic ligand model approach for addressing effects of exposure water chemistry on aquatic toxicity of metals: Genesis and challenges

    Science.gov (United States)

    A major uncertainty in many aquatic risk assessments for toxic chemicals is the aggregate effect of the physicochemical characteristics of exposure media on toxicity, and how this affects extrapolation of laboratory test results to natural systems. A notable example of this is h...

  8. Predicting Scenarios for Successful Autodissemination of Pyriproxyfen by Malaria Vectors from Their Resting Sites to Aquatic Habitats; Description and Simulation Analysis of a Field-Parameterizable Model.

    Directory of Open Access Journals (Sweden)

    Samson S Kiware

    Full Text Available Large-cage experiments indicate pyriproxifen (PPF can be transferred from resting sites to aquatic habitats by Anopheles arabiensis--malaria vector mosquitoes to inhibit emergence of their own offspring. PPF coverage is amplified twice: (1 partial coverage of resting sites with PPF contamination results in far higher contamination coverage of adult mosquitoes because they are mobile and use numerous resting sites per gonotrophic cycle, and (2 even greater contamination coverage of aquatic habitats results from accumulation of PPF from multiple oviposition events.Deterministic mathematical models are described that use only field-measurable input parameters and capture the biological processes that mediate PPF autodissemination. Recent successes in large cages can be rationalized, and the plausibility of success under full field conditions can be evaluated a priori. The model also defines measurable properties of PPF delivery prototypes that may be optimized under controlled experimental conditions to maximize chances of success in full field trials. The most obvious flaw in this model is the endogenous relationship that inevitably occurs between the larval habitat coverage and the measured rate of oviposition into those habitats if the target mosquito species is used to mediate PPF transfer. However, this inconsistency also illustrates the potential advantages of using a different, non-target mosquito species for contamination at selected resting sites that shares the same aquatic habitats as the primary target. For autodissemination interventions to eliminate malaria transmission or vector populations during the dry season window of opportunity will require comprehensive contamination of the most challenging subset of aquatic habitats [Formula: see text] that persist or retain PPF activity (Ux for only one week [Formula: see text], where Ux = 7 days. To achieve >99% contamination coverage of these habitats will necessitate values for the

  9. Habitat-specific bioaccumulation of methylmercury in invertebrates of small mid-latitude lakes in North America

    Energy Technology Data Exchange (ETDEWEB)

    Chetelat, John, E-mail: john.chetelat@ec.gc.c [Groupe de recherche interuniversitaire en limnologie, Departement de sciences biologiques, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada); Amyot, Marc; Garcia, Edenise [Groupe de recherche interuniversitaire en limnologie, Departement de sciences biologiques, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada)

    2011-01-15

    We examined habitat-specific bioaccumulation of methylmercury (MeHg) in aquatic food webs by comparing concentrations in pelagic zooplankton to those in littoral macroinvertebrates from 52 mid-latitude lakes in North America. Invertebrate MeHg concentrations were primarily correlated with water pH, and after controlling for this influence, pelagic zooplankton had significantly higher MeHg concentrations than littoral primary consumers but lower MeHg than littoral secondary consumers. Littoral primary consumers and pelagic zooplankton are two dominant prey for fish, and greater MeHg in zooplankton is likely sufficient to increase bioaccumulation in pelagic feeders. Intensive sampling of 8 lakes indicated that habitat-specific bioaccumulation in invertebrates (of similar trophic level) may result from spatial variation in aqueous MeHg concentration or from more efficient uptake of aqueous MeHg into the pelagic food web. Our findings demonstrate that littoral-pelagic differences in MeHg bioaccumulation are widespread in small mid-latitude lakes. - Methylmercury levels in dominant invertebrate prey for fish differ between littoral and pelagic habitats within a lake.

  10. Habitat-specific bioaccumulation of methylmercury in invertebrates of small mid-latitude lakes in North America

    International Nuclear Information System (INIS)

    We examined habitat-specific bioaccumulation of methylmercury (MeHg) in aquatic food webs by comparing concentrations in pelagic zooplankton to those in littoral macroinvertebrates from 52 mid-latitude lakes in North America. Invertebrate MeHg concentrations were primarily correlated with water pH, and after controlling for this influence, pelagic zooplankton had significantly higher MeHg concentrations than littoral primary consumers but lower MeHg than littoral secondary consumers. Littoral primary consumers and pelagic zooplankton are two dominant prey for fish, and greater MeHg in zooplankton is likely sufficient to increase bioaccumulation in pelagic feeders. Intensive sampling of 8 lakes indicated that habitat-specific bioaccumulation in invertebrates (of similar trophic level) may result from spatial variation in aqueous MeHg concentration or from more efficient uptake of aqueous MeHg into the pelagic food web. Our findings demonstrate that littoral-pelagic differences in MeHg bioaccumulation are widespread in small mid-latitude lakes. - Methylmercury levels in dominant invertebrate prey for fish differ between littoral and pelagic habitats within a lake.

  11. Aquatic Therapy for Children

    Science.gov (United States)

    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…

  12. Heavy Metal Bioaccumulation and Toxicity with Special Reference to Microalgae

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The bioaccumulation and toxicity of heavy metals were reviewed with special reference to microalgae, the key component of the food web in aquatic ecosystems. Heavy metals enter algal cells either by means of active transport or by endocytosis through chelating proteins and affect various physiological and biochemical processes of the algae. The toxicity primarily results from their binding to the sulphydryl groups in proteins or disrupting protein structure or displacing essential elements. Metals can break the oxidative balance of the algae, inducing antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and ascorbate peroxidase (APX). The amount of oxidized proteins and lipids in the algal cells thus indicates the severity of the stress. Algal tolerance to heavy metal is highly dependent upon the defense response against the probable oxidative damages. Production of binding factors and proteins, exclusion of metals from cells by ion-selective transporters and excretion or compartmentalization have been suggested with regard to reducing heavy metal toxicity. However, a comprehensive description on the mechanisms underlining metal toxicity of microalgae and gaining tolerance is yet to be elaborated.

  13. Triclosan: Current Status, Occurrence, Environmental Risks and Bioaccumulation Potential

    Directory of Open Access Journals (Sweden)

    Gurpreet Singh Dhillon

    2015-05-01

    Full Text Available Triclosan (TCS is a multi-purpose antimicrobial agent used as a common ingredient in everyday household personal care and consumer products. The expanded use of TCS provides a number of pathways for the compound to enter the environment and it has been detected in sewage treatment plant effluents; surface; ground and drinking water. The physico-chemical properties indicate the bioaccumulation and persistence potential of TCS in the environment. Hence, there is an increasing concern about the presence of TCS in the environment and its potential negative effects on human and animal health. Nevertheless, scarce monitoring data could be one reason for not prioritizing TCS as emerging contaminant. Conventional water and wastewater treatment processes are unable to completely remove the TCS and even form toxic intermediates. Considering the worldwide application of personal care products containing TCS and inefficient removal and its toxic effects on aquatic organisms, the compound should be considered on the priority list of emerging contaminants and its utilization in all products should be regulated.

  14. Arsenic bioaccumulation in a marine juvenile fish Terapon jarbua

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wei [State Key Laboratory of Oceanography in the Tropics, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Huang Liangmin [State Key Laboratory of Oceanography in the Tropics, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301 (China); Wang Wenxiong, E-mail: wwang@ust.hk [Division of Life Science, HKUST, Clear Water Bay, Kowloon (Hong Kong)

    2011-10-15

    Highlights: Radiotracer technique was used to quantify the biokinetics of As(V) in a marine fish. As(V) had a low bioavailability to Terapon jarbua. Dietary assimilation of As was only 3.1-7.4% for fish fed with different preys. Dietary uptake could be the primary route for As bioaccumulation in fish. - Abstract: Arsenic (As) is a ubiquitous toxic metalloid that is causing widespread public concern. Recent measurements have indicated that some marine fish in China might be seriously contaminated with As. Yet the biokinetics and bioaccumulation pathway of As in fish remain little understood. In this study, we employed a radiotracer technique to quantify the dissolved uptake, dietary assimilation and subsequent efflux of As(V) in a marine predatory fish, Terapon jarbua. The dissolved uptake of As showed a linear pattern over a range of dissolved concentrations from 0.5 to 50 {mu}g L{sup -1}, with a corresponding uptake rate constant of 0.0015 L g{sup -1} d{sup -1}. The assimilation efficiencies (AEs) of dietary As were only 3.1-7.4% for fish fed with copepods, clams, prey fish, or artificial diets, and were much lower than the As that entered the trophically available metal fraction in the prey. The dietary AEs were independent of the As(V) concentrations in the artificial diets. The efflux rate constant of As in fish following the dietary exposure was 0.03 d{sup -1}. Modeling calculations showed that dietary uptake could be the primary route for As bioaccumulation in fish, and the corresponding contributions of waterborne and dietary uptakes were related to the bioconcentration factor (BCF) of the prey and the ingestion rate of fish. This study demonstrates that As(V) has a low bioavailability to T. jarbua.

  15. Arsenic bioaccumulation in a marine juvenile fish Terapon jarbua

    International Nuclear Information System (INIS)

    Highlights: Radiotracer technique was used to quantify the biokinetics of As(V) in a marine fish. As(V) had a low bioavailability to Terapon jarbua. Dietary assimilation of As was only 3.1–7.4% for fish fed with different preys. Dietary uptake could be the primary route for As bioaccumulation in fish. - Abstract: Arsenic (As) is a ubiquitous toxic metalloid that is causing widespread public concern. Recent measurements have indicated that some marine fish in China might be seriously contaminated with As. Yet the biokinetics and bioaccumulation pathway of As in fish remain little understood. In this study, we employed a radiotracer technique to quantify the dissolved uptake, dietary assimilation and subsequent efflux of As(V) in a marine predatory fish, Terapon jarbua. The dissolved uptake of As showed a linear pattern over a range of dissolved concentrations from 0.5 to 50 μg L−1, with a corresponding uptake rate constant of 0.0015 L g−1 d−1. The assimilation efficiencies (AEs) of dietary As were only 3.1–7.4% for fish fed with copepods, clams, prey fish, or artificial diets, and were much lower than the As that entered the trophically available metal fraction in the prey. The dietary AEs were independent of the As(V) concentrations in the artificial diets. The efflux rate constant of As in fish following the dietary exposure was 0.03 d−1. Modeling calculations showed that dietary uptake could be the primary route for As bioaccumulation in fish, and the corresponding contributions of waterborne and dietary uptakes were related to the bioconcentration factor (BCF) of the prey and the ingestion rate of fish. This study demonstrates that As(V) has a low bioavailability to T. jarbua.

  16. Radionuclide Transport and Uptake in Coastal Aquatic Ecosystems: A Comparison of a 3D Dynamic Model and a Compartment Model

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe [Ecological and Environmental Dept., DHI, Hoersholm (Denmark)], E-mail: aer@dhigroup.com; Konovalenko, Lena; Bradshaw, Clare [The Dept. of Ecology, Environment and Plant Sciences, Stockholm Univ., Stockholm (Sweden); Kautsky, Ulrik [Swedish Nuclear Fuel and Waste Management Co. (SKB), Stockholm (Sweden); Aquilonius, Karin [Studsvik Nuclear AB, Nykoeping (Sweden)

    2013-05-15

    In safety assessments of underground radioactive waste repositories, understanding radionuclide fate in ecosystems is necessary to determine the impacts of potential releases. Here, the reliability of two mechanistic models (the compartmental K-model and the 3D dynamic D-model) in describing the fate of radionuclides released into a Baltic Sea bay is tested. Both are based on ecosystem models that simulate the cycling of organic matter (carbon). Radionuclide transfer is linked to adsorption and flows of carbon in food chains. Accumulation of Th-230, Cs-135, and Ni-59 in biological compartments was comparable between the models and site measurements despite differences in temporal resolution, biological state variables, and partition coefficients. Both models provided confidence limits for their modeled concentration ratios, an improvement over models that only estimate means. The D-model enables estimates at high spatio-temporal resolution. The K-model, being coarser but faster, allows estimates centuries ahead. Future developments could integrate the two models to take advantage of their respective strengths.

  17. Radionuclide transport and uptake in coastal aquatic ecosystems - a comparison of a 3D dynamic model and a compartment model

    Energy Technology Data Exchange (ETDEWEB)

    Konovalenko, L.; Bradshaw, C. [The Department of Ecology, Environment and Plant Sciences Stockholm University (Sweden); Erichsen, A.C.; Moehlenberg, F. [Ecological and Environmental Department DHI (Sweden); Kautsky, U. [Swedish Nuclear Fuel and Waste Management Co - SKB (Sweden)

    2014-07-01

    In safety assessments of underground radioactive waste repositories, understanding the fate of radionuclides in ecosystems is necessary. Here, two mechanistic models (K- and D- model) describing the fate of radionuclides released into a Baltic Sea bay were compared. Both are based on ecosystem models that simulate the cycling of organic matter. Parallel to adsorption, transfer of radionuclides is linked to flows of organic matter (carbon) in food chains. Despite differences in temporal resolution, biological state variables and partition coefficients, the accumulation of Th-230, Cs-135 and Ni-59 in biological compartments was comparable between the models and with site measurements. Both models provided confidence limits for their modeled concentration ratios, an improvement over models that only estimate mean values. The D-model enables estimates at high spatio-temporal resolution. The K-model being coarser but faster, allows estimates centuries ahead. Future developments could integrate the two models to take full advantage of their respective strengths. Document available in abstract form only. (authors)

  18. Understanding carbon regulation in aquatic systems - Bacteriophages as a model [v1; ref status: indexed, http://f1000r.es/4zd

    Directory of Open Access Journals (Sweden)

    Swapnil Sanmukh

    2015-06-01

    Full Text Available The bacteria and their phages are the most abundant constituents of the aquatic environment, and so represent an ideal model for studying carbon regulation in an aquatic system. The microbe-mediated interconversion of bioavailable organic carbon (OC into dissolved organic carbon (DOC by the microbial carbon pump (MCP has been suggested to have the potential to revolutionize our view of carbon sequestration. It is estimated that DOC is the largest pool of organic matter in the ocean and, though a major component of the global carbon cycle, its source is not yet well understood. A key element of the carbon cycle is the microbial conversion of DOC into inedible forms. The primary aim of this study is to understand the phage conversion from organic to inorganic carbon during phage-host interactions. Time studies of phage-host interactions under controlled conditions reveal their impact on the total carbon content of the samples and their interconversion of organic and inorganic carbon compared to control samples. A total organic carbon (TOC analysis showed an increase in inorganic carbon content by 15-25 percent in samples with bacteria and phage compared to samples with bacteria alone. Compared to control samples, the increase in inorganic carbon content was 60-70-fold in samples with bacteria and phage, and 50-55-fold for samples with bacteria alone. This study indicates the potential impact of phages in regulating the carbon cycle of aquatic systems.

  19. Assessment of aquatic plants in the reservoirs of AES-tietê and development of an integrated control model for the most important species.

    Science.gov (United States)

    Velini, Edivaldo Domingues; Galo, Maria Lourdes B T; Carvalho, Fernando Tadeu; Martins, Dagoberto; Cavenaghi, Anderson Luis; Trindade, Maria Lúcia Bueno; Bravin, Luis Fernando N; Negrisoli, Eduardo; Antuniassi, Ulisses Rocha; Simionato, José L A; Santos, Silvio C A

    2005-01-01

    The general objective of this work was to develop a monitoring and management model for aquatic plants that could be used in reservoir cascades in Brazil, using the reservoirs of AES-Tietê as a study case. The investigations were carried out at the reservoirs of Barra-Bonita, Bariri, Ibitinga, Promissão, and Nova-Avanhandava, located in the Tietê River Basin; Agua Vermelha, located in the Grande River Basin; Caconde, Limoeiro, and Euclides da Cunha, which are part of the Pardo River Basin; and the Mogi-Guaçu reservoir, which belongs to the Mogi-Guaçu River basin. The main products of this work were: development of techniques using satellite-generated images for monitoring and planning aquatic plant control; planning and construction of a boat to move coating plant masses and an airboat equipped with a DGPS navigation and application flow control system. Results allowed to conclude that the occurrence of all types of aquatic plants is directly associated with sedimentation process and, consequently, with nutrient and light availability. Reservoirs placed at the beginning of cascades are more subject to sedimentation and occurrence of marginal, floating and emerged plants, and are the priority when it comes to controlling these plants, since they provide a supply of weeds for the other reservoirs. Reservoirs placed downstream show smaller amounts of water-suspended solids, with greater transmission of light and occurrence of submerged plants. PMID:15656166

  20. Bioaccumulation patterns of methyl mercury and essential fatty acids in lacustrine planktonic food webs and fish.

    Science.gov (United States)

    Kainz, Martin; Telmer, Kevin; Mazumder, Asit

    2006-09-01

    Organisms of the planktonic food web convey essential nutrients as well as contaminants to animals at higher trophic levels. We measured concentrations of methyl mercury (MeHg) and essential fatty acids (EFAs, key nutrients for aquatic food webs) in four size categories of planktonic organisms - seston (10-64 microm), micro-(100-200 microm), meso-(200-500 microm), and macrozooplankton (>500 microm) - as well as total mercury (THg) and EFAs in rainbow trout (Oncorhynchus mykiss) in coastal lakes. We demonstrate that, in all lakes during this summer sampling, MeHg concentrations of planktonic organisms increase significantly with plankton size, independent of their taxonomic composition, and that their MeHg accumulation patterns predict significantly THg concentrations in rainbow trout (R2=0.71, pzooplankton size fraction. Moreover, concentrations of individual EFA compounds in rainbow trout are consistently lower, with the exception of docosahexaenoic acid, than those in macrozooplankton. The continuous increase of MeHg concentrations in aquatic organisms, therefore, differs from patterns of EFA accumulation in zooplankton and fish. We interpret these contrasting accumulation patterns of MeHg and EFA compounds as the inability of aquatic organisms to regulate the assimilation of dietary MeHg, whereas the rate of EFA retention may be controlled to optimize their physiological performance. Therefore, we conclude that bioaccumulation patterns of Hg in these aquatic food webs are not controlled by lipid solubility and/or the retention of EFA compounds. PMID:16226794

  1. Forecasting fish biomasses, densities, productions, and bioaccumulation potentials of Mid-Atlantic wadeable streams

    Science.gov (United States)

    Regional fishery conditions of Mid-Atlantic wadeable streams in the eastern United States are estimated using the BASS bioaccumulation and fish community model and data collected by the U.S. Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP)....

  2. Combined effects of sugarcane bagasse extract and Zinc(II ions on the growth and bioaccumulation properties of yeast isolates.

    Directory of Open Access Journals (Sweden)

    Geetanjali Basak

    2011-08-01

    Full Text Available Bioaccumulation of zinc(II ions by yeast isolates viz. Candida rugosa and Cryptococcus laurentii was investigated in different growth media. Both the isolates showed maximum bioaccumulation of zinc(II in the medium prepared from sugarcane bagasse extract. The growth and zinc(II bioaccumulation properties of yeasts in sugar cane bagasse extract were tested as a function of pH, temperature and initial metal concentrations. The combined effects of sugar extracted from bagasse and initial zinc(II ion concentrations on specific growth rate and bioaccumulation efficiencies of yeasts were investigated. At a constant zinc(II concentration, the growthand zinc(II bioaccumulation increased with increasing concentrations of sugar up to 24 g/L. The inhibition effect of zinc(II ions on the specific growth rate of yeasts was studied by non competitive and uncompetitive inhibition models at various concentrations of zinc(II ranging from 0-50 mg/L at constant sugar concentrations (8- 24 g/L. Bioaccumulation of zinc(II by the yeast isolates followed first-order-reaction kinetics.

  3. Application of potassium chloride to a Chernobyl-contaminated lake. Modelling the dynamics of radiocaesium in an aquatic ecosystem and decontamination of fish

    International Nuclear Information System (INIS)

    This study tests a whole-lake experiment to reduce the bioaccumulation of radiocaesium (137Cs) in fish in lakes contaminated by the Chernobyl accident. In many lakes in the Chernobyl contaminated areas, radiocaesium activity concentrations in fish are still significantly higher (up to 100 times in some species) than acceptable limits for human consumption. Estimates of the long-term rate of decline of 137Cs in fish in these regions, in the absence of countermeasures, show that radioactivity in fish in some lakes may remain above acceptable consumption limits for a further 50-100 years from the present date. In February 1998 we applied 15 t of potassium chloride to Lake Svyatoe, Kostiukovichy. The addition of potassium chloride fertilizer to the lake resulted in a decrease in activity concentration of 137Cs to approximately 40% of pre-countermeasure values in a number of different fish species. In contrast to Lake Svyatoe, 137Cs activity concentrations in fish from four control lakes showed no systematic decrease over the study period. Simplified models for transfers of 137Cs in lakes successfully 'blind' predicted the changes in 137Cs in water and fish resulting from this major alteration of the potassium concentration of the lake. The experiment represents the first test of a predictive model for the dynamics of radiocaesium in response to a major perturbation in potassium (its major competitor ion) in a whole lake ecosystem

  4. Production in aquatic macrophyte communities

    DEFF Research Database (Denmark)

    Binzer, Thomas; Sand-Jensen, Kaj

    2002-01-01

    -dimensional structure because of the strong drag and shear forces of moving water. This difference in canopy structure has been suggested to account for the three- to fivefold higher gross production rates in terrestrial than aquatic communities. To evaluate the effect of community structure in aquatic habitats, we...... combined a simple mechanistic model and empirical measurements on artificially structured macroalgal communities (Ulva lactuca) with varying thallus absorptance and community density. Predicted and measured values corresponded closely and revealed that gross production in high-light environments...... was markedly enhanced by a vertical orientation of thalli when absorptance and community density were both high. This result implies that aquatic macrophytes of high thallus absorptance and community density exposed to high light are limited in attaining high gross production rates because of their inability...

  5. Macrophytes: Ecology of aquatic plants

    NARCIS (Netherlands)

    Bornette, G.; Puijalon, S.

    2009-01-01

    Aquatic plants contribute to maintaining key functions and related biodiversity in freshwater ecosystems, and to provide the needs of human societies. The way the ecological niches of macrophytes are determined by abiotic filters and biotic ones is considered. A simple, broadly applicable model of t

  6. Bioaccumulation of the synthetic dye Basic Violet 3 and heavy metals in single and binary systems by Candida tropicalis grown in a sugarcane bagasse extract medium: Modelling optimal conditions using response surface methodology (RSM) and inhibition kinetics

    International Nuclear Information System (INIS)

    Single and binary effects of dye Basic Violet 3 and heavy metals, 'namely', Pb(II) and Cd(II), were investigated for their role in dye and heavy metal bioaccumulation by Candida tropicalis that was grown in a sugarcane bagasse extract medium containing 8 g/L, 16 g/L or 24 g/L of sugar. The optimum pH was found to be 4.0 in the single system and 5.0 in the binary system. A central composite design was successfully used to analyse the experimental results. Four numerical correlations that were fitted to a second order quadratic equation were used to estimate optimum combinations predicted by response surface methodology. In the dye-Pb(II) binary system, C. tropicalis was capable of bioaccumulating 49.5% of the dye and 49.6% of the Pb(II), in comparison to 15.9% of the dye and 55.5% of the Cd(II) in the dye-Cd(II) binary system. In these two systems, the pollutants were dispersed at minimum working concentration levels. Competitive inhibition was observed in both the single and binary systems, which was suggested by an increase in the saturation constant, Ks, and a simultaneous decrease in the specific growth rate that was calculated from Lineweaver-Burk plots. Atomic force microscopy images demonstrated changes in yeast cell morphology by exposure to these contaminants in the dye-Pb(II) binary system grown in a bioaccumulation medium.

  7. Species-specific mercury bioaccumulation in a diverse fish community.

    Science.gov (United States)

    Donald, David B; Wissel, Björn; Anas, M U Mohamed

    2015-12-01

    Mercury bioaccumulation models developed for fish provide insight into the sources and transfer of Hg within ecosystems. Mercury concentrations were assessed for 16 fish species of the western reach of Lake Diefenbaker, Saskatchewan, Canada. For top predators (northern pike, Esox Lucius; walleye, Sander vitreum), Hg concentrations were positively correlated to δ(15)N, and δ(15)N to fish age, suggesting that throughout life these fish fed on organisms with increasingly higher trophic values and Hg concentrations. However, fish mass and/or age were the principal parameters related to Hg concentrations for most species. For 9 common species combined, individual variation in Hg concentration was explained in declining order of importance by fish mass, trophic position (δ(15)N), and fish age. Delta (15)N value was not the leading variable related to Hg concentration for the assemblage, probably because of the longevity of lower--trophic-level species (3 species ≥ 20 yr), substantial overlap in Hg concentration and δ(15)N values for large-bodied fish up to 3000 g, and complex relationships between Hg concentration and δ(15)N among species. These results suggest that the quantity of food (and Hg) consumed each year and converted to fish mass, the quantity of Hg bioaccumulated over years and decades, and trophic position were significant determinants of Hg concentration in Lake Diefenbaker fish.

  8. Arsenic bioaccumulation in a marine juvenile fish Terapon jarbua.

    Science.gov (United States)

    Zhang, Wei; Huang, Liangmin; Wang, Wen-Xiong

    2011-10-01

    Arsenic (As) is a ubiquitous toxic metalloid that is causing widespread public concern. Recent measurements have indicated that some marine fish in China might be seriously contaminated with As. Yet the biokinetics and bioaccumulation pathway of As in fish remain little understood. In this study, we employed a radiotracer technique to quantify the dissolved uptake, dietary assimilation and subsequent efflux of As(V) in a marine predatory fish, Terapon jarbua. The dissolved uptake of As showed a linear pattern over a range of dissolved concentrations from 0.5 to 50 μg L(-1), with a corresponding uptake rate constant of 0.0015 L g(-1)d(-1). The assimilation efficiencies (AEs) of dietary As were only 3.1-7.4% for fish fed with copepods, clams, prey fish, or artificial diets, and were much lower than the As that entered the trophically available metal fraction in the prey. The dietary AEs were independent of the As(V) concentrations in the artificial diets. The efflux rate constant of As in fish following the dietary exposure was 0.03 d(-1). Modeling calculations showed that dietary uptake could be the primary route for As bioaccumulation in fish, and the corresponding contributions of waterborne and dietary uptakes were related to the bioconcentration factor (BCF) of the prey and the ingestion rate of fish. This study demonstrates that As(V) has a low bioavailability to T. jarbua. PMID:21945928

  9. Bioaccumulation of radiocaesium in Arctic seals

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, JoLynn; Wolkers, Hans; Andersen, Magnus; Rissanen, Kristina

    2002-12-01

    Seals are high trophic level feeders that bioaccumulate many contaminants to a greater degree than most lower trophic level organisms. Their trophic status in the marine food web and wide-spread distribution make seals useful sentinels of arctic environmental change. The purpose of this investigation is to document the levels and bioaccumulation potential of radiocaesium in high latitude seal species for which data have not previously been available. The study was carried out on harp, ringed, and bearded seals caught north of the island archipelago of Svalbard (82 deg. N) in 1999. The results are then compared with previous studies in order to elucidate factors responsible for bioaccumulation in Arctic seals. Concentrations of {sup 137}Cs were determined in muscle, liver and kidney samples from a total of 10 juvenile and one adult seal. The mean concentration in muscle samples for all animals was 0.23{+-}0.045 Bq/kg f.w. {sup 137}Cs concentrations in both liver and kidney samples were near detection limits ({approx}0.2 Bq/kg f.w.). The results are consistent with previous studies indicating low levels of radiocaesium in Arctic seals in response to a long term trend of decreasing levels of {sup 137}Cs in the Barents Sea region. Bioconcentration factors (BCFs) estimated for seals from NE Svalbard are low, ranging from 34 to 130. Comparing these values with reported BCFs for Greenland seals from other sectors of the European Arctic, we suggest that the combination of physiological and ecological factors on radiocaesium bioaccumulation is comparable among different Arctic seal populations. The application of this work to Arctic monitoring and assessment programs is discussed.

  10. A protocell design for bioaccumulation applications

    OpenAIRE

    von Hegner, Ian

    2015-01-01

    This article provides a specific example of recombinant cell and protocell technology, moving from what is presently known to suggesting how novel application of existing methodologies could be utilized to design a complex synthetic system in form of a self-sufficient light empowered protocell. A practical application of protocells using a primary example of desalination in water treatment is given, followed by a more general approach to bioaccumulation and bio-diagnostics, outlining the poss...

  11. An investigation into ciguatoxin bioaccumulation in sharks.

    Science.gov (United States)

    Meyer, Lauren; Capper, Angela; Carter, Steve; Simpfendorfer, Colin

    2016-09-01

    Ciguatoxins (CTXs) produced by benthic Gambierdiscus dinoflagellates, readily biotransform and bioaccumulate in food chains ultimately bioconcentrating in high-order, carnivorous marine species. Certain shark species, often feeding at, or near the top of the food-chain have the ability to bioaccumulate a suite of toxins, from both anthropogenic and algal sources. As such, these apex predators are likely sinks for CTXs. This assumption, in conjunction with anecdotal knowledge of poisoning incidents, several non-specific feeding trials whereby various terrestrial animals were fed suspect fish flesh, and a single incident in Madagascar in 1994, have resulted in the widespread acceptance that sharks may accumulate CTXs. This prompted a study to investigate original claims within the literature, as well as investigate CTX bioaccumulation in the muscle and liver of 22 individual sharks from nine species, across four locations along the east coast of Australia. Utilizing an updated ciguatoxin extraction method with HPLC-MS/MS, we were unable to detect P-CTX-1, P-CTX-2 or P-CTX-3, the three primary CTX congeners, in muscle or liver samples. We propose four theories to address this finding: (1) to date, methods have been optimized for teleost species and may not be appropriate for elasmobranchs, or the CTXs may be below the limit of detection; (2) CTX may be biotransformed into elasmobranch-specific congeners as a result of unique metabolic properties; (3) 22 individuals may be an inadequate sample size given the rare occurrence of high-order ciguatoxic organisms and potential for CTX depuration; and (4) the ephemeral nature and inconsistent toxin profiles of Gambierdiscus blooms may have undermined our classifications of certain areas as CTX hotspots. These results, in combination with the lack of clarity within the literature, suggest that ciguatoxin bioaccumulation in sharks remains elusive, and warrants further investigation to determine the dynamics of toxin production

  12. Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife

    Science.gov (United States)

    Eagles-Smith, Collin A.; Wiener, James G.; Eckley, Chris S.; Willacker, James J.; Evers, David C.; Marvin-DiPasquale, Mark C.; Obrist, Daniel; Fleck, Jacob; Aiken, George R.; Lepak, Jesse M.; Jackson, Allyson K.; Webster, Jackson; Stewart, Robin; Davis, Jay; Alpers, Charles N.; Ackerman, Josh

    2016-01-01

    Western North America is a region defined by extreme gradients in geomorphology and climate, which support a diverse array of ecological communities and natural resources. The region also has extreme gradients in mercury (Hg) contamination due to a broad distribution of inorganic Hg sources. These diverse Hg sources and a varied landscape create a unique and complex mosaic of ecological risk from Hg impairment associated with differential methylmercury (MeHg) production and bioaccumulation. Understanding the landscape-scale variation in the magnitude and relative importance of processes associated with Hg transport, methylation, and MeHg bioaccumulation requires a multidisciplinary synthesis that transcends small-scale variability. The Western North America Mercury Synthesis compiled, analyzed, and interpreted spatial and temporal patterns and drivers of Hg and MeHg in air, soil, vegetation, sediments, fish, and wildlife across western North America. This collaboration evaluated the potential risk from Hg to fish, and wildlife health, human exposure, and examined resource management activities that influenced the risk of Hg contamination. This paper integrates the key information presented across the individual papers that comprise the synthesis. The compiled information indicates that Hg contamination is widespread, but heterogeneous, across western North America. The storage and transport of inorganic Hg across landscape gradients are largely regulated by climate and land-cover factors such as plant productivity and precipitation. Importantly, there was a striking lack of concordance between pools and sources of inorganic Hg, and MeHg in aquatic food webs. Additionally, water management had a widespread influence on MeHg bioaccumulation in aquatic ecosystems, whereas mining impacts where relatively localized. These results highlight the decoupling of inorganic Hg sources with MeHg production and bioaccumulation. Together the findings indicate that developing

  13. Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife.

    Science.gov (United States)

    Eagles-Smith, Collin A; Wiener, James G; Eckley, Chris S; Willacker, James J; Evers, David C; Marvin-DiPasquale, Mark; Obrist, Daniel; Fleck, Jacob A; Aiken, George R; Lepak, Jesse M; Jackson, Allyson K; Webster, Jackson P; Stewart, A Robin; Davis, Jay A; Alpers, Charles N; Ackerman, Joshua T

    2016-10-15

    Western North America is a region defined by extreme gradients in geomorphology and climate, which support a diverse array of ecological communities and natural resources. The region also has extreme gradients in mercury (Hg) contamination due to a broad distribution of inorganic Hg sources. These diverse Hg sources and a varied landscape create a unique and complex mosaic of ecological risk from Hg impairment associated with differential methylmercury (MeHg) production and bioaccumulation. Understanding the landscape-scale variation in the magnitude and relative importance of processes associated with Hg transport, methylation, and MeHg bioaccumulation requires a multidisciplinary synthesis that transcends small-scale variability. The Western North America Mercury Synthesis compiled, analyzed, and interpreted spatial and temporal patterns and drivers of Hg and MeHg in air, soil, vegetation, sediments, fish, and wildlife across western North America. This collaboration evaluated the potential risk from Hg to fish, and wildlife health, human exposure, and examined resource management activities that influenced the risk of Hg contamination. This paper integrates the key information presented across the individual papers that comprise the synthesis. The compiled information indicates that Hg contamination is widespread, but heterogeneous, across western North America. The storage and transport of inorganic Hg across landscape gradients are largely regulated by climate and land-cover factors such as plant productivity and precipitation. Importantly, there was a striking lack of concordance between pools and sources of inorganic Hg, and MeHg in aquatic food webs. Additionally, water management had a widespread influence on MeHg bioaccumulation in aquatic ecosystems, whereas mining impacts where relatively localized. These results highlight the decoupling of inorganic Hg sources with MeHg production and bioaccumulation. Together the findings indicate that developing

  14. Bioaccumulation of gasoline in brackish green algae and popular clams

    Directory of Open Access Journals (Sweden)

    Gihan A. El-Shoubaky

    2016-03-01

    Full Text Available The green algae (Ulva lactuca and Enteromorpha clathrata and the clams (Tapes decussates and Venerupis aurea grow together in Timsah Lake, Suez Canal, Egypt. Our ultimate goal is to validate the bioaccumulation of gasoline in the marine organisms and their behavior after exposure to the pollutant, experimentally. These species were treated with a serial treatment of gasoline (1000, 4000, 16,000 and 64,000 μl in aquaria with brackish sea-water for 72 h. The tested green algae and clams were taken for an analysis of total hydrocarbon accumulation daily. The statistical analysis showed significant differences between the four species and also between the duration of exposure. The accumulation of gasoline in U. lactuca and E. clathrata reached their maximum after 48 h at 1000 and 4000 μl. The highest absorption was registered after 24 h only at 16,000 and at 64,000 μl. U. lactuca recorded complete mortality in 64,000 μl at 72 h whereas E. clathrata registered death at 48 h and 72 h in the same treatment. V. aurea was more sensitive than T. decussates. The accumulation of gasoline reached its maximum in V. aurea after only 24 h in the first treatment while it retarded to 48 h in T. decussates with a lesser accumulation. However, both clam species accumulated the highest amount of petroleum hydrocarbons during the first hour of exposure at the first treatment. In the third and fourth treatments, clams did not accumulate gasoline but began to dispose it from their tissues till it became less than that in the control. Mortality gradually increased with time in each treatment except the last one (64,000 μl in which 100% death of the specimens was observed. In general, the bioaccumulation of gasoline level was in a descending order as follows: U. lactuca > E. clathrata > V. aurea > T. decussates. Their behavior changed from accumulation to detoxification with time and with the increase in pollutant concentration. Generally, these

  15. Bioaccumulation of selected heavy metals by the water fern, Azolla filiculoides Lam. in a wetland ecosystem affected by sewage, mine and industrial pollution

    Energy Technology Data Exchange (ETDEWEB)

    Wet, L.P.D. de; Schoonbee, H.J.; Pretorius, J.; Bezuidenhout, L.M. (Rand Afrikaans University, Johannesburg (South Africa). Depts. of Zoology and Botany, Research Unit for Aquatic and Terrestrial Ecosystems)

    1990-10-01

    The bio-accumulation of the heavy metals, Fe, Cu, Ni, Pb, Zn, Mn and Cr by the water fern, Azolla filiculoides Lam. in a wetland ecosystem polluted by effluents from sewage works, mines and industries was investigated. Results showed that the different metals can be accumulated by the water fern at concentration levels not necessarily related to their actual concentrations in the aquatic environment, as measured in this case, in the bottom sediments. 45 refs., 1 fig., 3 tabs.

  16. The Relative Influence of Aquatic and Terrestrial Processes on Methylmercury Transport in River Basins

    Science.gov (United States)

    Burns, D. A.; Bradley, P. M.; Marvin-DiPasquale, M. C.; Aiken, G.; Brigham, M. E.

    2012-12-01

    Conceptual understanding of the mercury (Hg) cycle in river basins is important for the development of improved Hg models that can inform Hg emissions policies, and, therefore, decrease the health risk that stems from widespread high Hg levels found in fresh water fish throughout the US and globally. Distinguishing the relative roles of aquatic and terrestrial ecosystems in Hg transport and transformation is fundamental to improved Hg risk management. The principal zones where Hg is transformed to its methyl form (MeHg), the transport of that MeHg to aquatic ecosystems, and subsequent bioaccumulation in aquatic food webs have been the focus of our investigations for more than 10 years in several small river basins across the US. Our data indicate that most MeHg in these rivers originates at the interface of the terrestrial and aquatic ecosystem in wetlands and riparian areas where anaerobic conditions and abundant organic matter favor methylation. Key factors in addition to methylation potential are those that influence the hydrologic transport of MeHg to adjacent streams and rivers such as hydraulic conductivity in the shallow subsurface and the depth of the water table in riparian areas. The presence and quality of organic matter in wetland soils and in water that moves through wetland areas also plays a pivotal role in MeHg source and transport. We discuss how these factors affect aquatic MeHg concentrations in light of a recently completed investigation of the Hg cycle in river basins in the Adirondack Mountains of New York and Coastal Plain of South Carolina. At each site, MeHg originates primarily in riparian wetland areas and is transported to the streams via shallow groundwater flow. The presence of open water bodies in these basins favors losses of MeHg by any of several processes, though smaller open water bodies may act as net MeHg sources. Ongoing work is building on this conceptualization of the Hg cycle through development of a model based on the

  17. Bioaccumulation of Pb and Cd on Broiler Chicken Fed in Difference Diets

    Directory of Open Access Journals (Sweden)

    Bambang Dwiloka

    2012-10-01

    Full Text Available The study was aimed to compute Pb and Cd bioaccumulation in different organs of broiler. Carcass, heart, liver, gizzard, intestine, and excreta. The data were obtained from broiler reared in the litter cage. Four treatments of feed were given to the broiler chicken, i.e.  T1 = X brand of commercial feed, T2 = Y brand of commercial feed, T3 = self-prepared feed without fish meal addition and T4 = self prepared feed without fish meal but contaminated with cadmium chloride (Cd.Cl2.4H2O. For each treatment, five broiler chicken were grouped each week (from week I up to week VI. Results of the first stage of this study was analyzed descriptively. A polinomial regression equation was used as an empirical model to describe the heavy metal bioaccumulation phenomenon in broiler carcasses. The quadratic equation  turned out to be the most suitable model for describing the bioaccumulation of heavy metal in broiler carcasses. From the simulation, it was found that  quadratic model fit to 61.31% and 54.17%  bioaccumulation data of Pb and Cd respectively. According to the model, initially metal concentrations declined since the first week and started to rebound at the fifth week, both in terms of chronological and physiological age. The patterns of Pb and Cd bioaccumulation in this study can be used as a reference to determine the proper slaughter period. It can be concluded that for reducing the risk of metal contamination the proper slaughter time of the broiler is before the fifth week.

  18. Watershed and Hydrodynamic Modeling for Evaluating the Impact of Land Use Change on Submerged Aquatic Vegetation and Seagrasses in Mobile Bay

    Science.gov (United States)

    Estes, Maurice G.; Al-Hamdan, Mohammed; Thom, Ron; Quattrochi, Dale; Woodruff, Dana; Judd, Chaeli; Ellism Jean; Watson, Brian; Rodriguez, Hugo; Johnson, Hoyt

    2009-01-01

    There is a continued need to understand how human activities along the northern Gulf of Mexico coast are impacting the natural ecosystems. The gulf coast is experiencing rapid population growth and associated land cover/land use change. Mobile Bay, AL is a designated pilot region of the Gulf of Mexico Alliance (GOMA) and is the focus area of many current NASA and NOAA studies, for example. This is a critical region, both ecologically and economically to the entire United States because it has the fourth largest freshwater inflow in the continental USA, is a vital nursery habitat for commercially and recreational important fisheries, and houses a working waterfront and port that is expanding. Watershed and hydrodynamic modeling has been performed for Mobile Bay to evaluate the impact of land use change in Mobile and Baldwin counties on the aquatic ecosystem. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for land use Scenarios in 1948, 1992, 2001, and 2030. The Prescott Spatial Growth Model was used to project the 2030 land use scenario based on observed trends. All land use scenarios were developed to a common land classification system developed by merging the 1992 and 2001 National Land Cover Data (NLCD). The LSPC model output provides changes in flow, temperature, sediments and general water quality for 22 discharge points into the Bay. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment concentrations on a grid with four vertical profiles throughout the Bay s aquatic ecosystems. The models were calibrated using in-situ data collected at sampling stations in and around Mobile bay. This phase of the project has focused on sediment modeling because of its significant influence on light attenuation which is a critical factor in the health of submerged aquatic

  19. Bioaccumulation of silver nanoparticles in rainbow trout (Oncorhynchus mykiss): Influence of concentration and salinity

    Energy Technology Data Exchange (ETDEWEB)

    Salari Joo, Hamid, E-mail: h.salary1365@gmail.com [Department of Aquaculture, Marine Science Faculty, Tarbiat Modares University, Mazandaran, Noor (Iran, Islamic Republic of); Kalbassi, Mohammad Reza, E-mail: kalbassi_m@modares.ac.ir [Department of Aquaculture, Marine Science Faculty, Tarbiat Modares University, Mazandaran, Noor (Iran, Islamic Republic of); Yu, Il Je, E-mail: u1670916@chol.com [Institute of Nano-product Safety Research, Hoseo University, 165 Sechul-ri, Baebang-myun, Asan 336-795 (Korea, Republic of); Lee, Ji Hyun, E-mail: toxin@dreamwiz.com [Institute of Nano-product Safety Research, Hoseo University, Asan (Korea, Republic of); Johari, Seyed Ali, E-mail: a.johari@uok.ac.ir [Aquaculture Department, Natural Resources Faculty, University of Kurdistan, Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2013-09-15

    Highlights: •We studied influence of concentration and salinity on bioaccumulation of silver nanoparticles in rainbow trout (Oncorhynchus mykiss). •The Ag-NPs were characterized using standard methods. •The organisms were exposed to Ag-NPs in three different salinity concentrations, for 14 days in static renewal systems. •The bioaccumulation of Ag in the studied tissues was concentration-dependent in all the salinities and its order were liver > kidneys ≈ gills > white muscles respectively. -- Abstract: With the increasing use of silver nanoparticles (Ag-NPs), their entrance into aquatic ecosystems is inevitable. Thus, the present study simulated the potential fate, toxicity, and bioaccumulation of Ag-NPs released into aquatic systems with different salinities. The Ag-NPs were characterized using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), dynamic light scattering (DLS), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), and UV–vis spectroscopy. Juvenile rainbow trout were exposed to Ag-NPs in three different salinity concentrations, including low (0.4 ppt), moderate (6 ± 0.3 ppt), and high (12 ± 0.2 ppt) salinity, for 14 days in static renewal systems. The nominal Ag-NP concentrations in the low salinity were 0.032, 0.1, 0.32, and 1 ppm, while the Ag-NP concentrations in the moderate and high salinity were 3.2, 10, 32, and 100 ppm. UV–vis spectroscopy was used during 48 h (re-dosing time) to evaluate the stability and possible changes in size of the Ag-NPs in the water. The results revealed that the λ{sub max} of the Ag-NPs remained stable (415–420 nm) at all concentrations in the low salinity with a reduction of absorbance between 380 and 550 nm. In contrast, the λ{sub max} quickly shifted to a longer wavelength and reduced absorbance in the moderate and higher salinity. The bioaccumulation of Ag in the studied tissues was concentration-dependent in all the salinities based on the following

  20. Lake Bathymetric Aquatic Vegetation

    Data.gov (United States)

    Minnesota Department of Natural Resources — Aquatic vegetation represented as polygon features, coded with vegetation type (emergent, submergent, etc.) and field survey date. Polygons were digitized from...

  1. Fluvial geomorphology and aquatic-to-terrestrial Hg export are weakly coupled in small urban streams of Columbus, Ohio

    Science.gov (United States)

    Sullivan, S. Mažeika P.; Boaz, Lindsey E.; Hossler, Katie

    2016-04-01

    Although mercury (Hg) contamination is common in stream ecosystems, mechanisms governing bioavailability and bioaccumulation in fluvial systems remain poorly resolved as compared to lentic systems. In particular, streams in urbanized catchments are subject to fluvial geomorphic alterations that may contribute to Hg distribution, bioaccumulation, and export across the aquatic-to-terrestrial boundary. In 12 streams of urban Columbus, Ohio, we investigated the influence of fluvial geomorphic characteristics related to channel geometry, streamflow, and sediment size and distribution on (1) Hg concentrations in sediment and body burdens in benthic larval and adult emergent aquatic insects and (2) aquatic-to-terrestrial contaminant transfer to common riparian spiders of the families Pisauridae and Tetragnathidae via changes in aquatic insect Hg body burdens as well as in aquatic insect density and community composition. Hydrogeomorphic characteristics were weakly related to Hg body burdens in emergent insects (channel geometry) and tetragnathid spiders (streamflow), but not to Hg concentrations in sediment or benthic insects. Streamflow characteristics were also related to emergent insect density, while wider channels were associated with benthic insect community shifts toward smaller-bodied and more tolerant taxa (e.g., Chironomidae). Thus, our results provide initial evidence that fluvial geomorphology may influence aquatic-to-terrestrial contaminant Hg transfer through the collective effects on emergent insect body burdens as well as on aquatic insect community composition and abundance.

  2. A rational approach to selecting and ranking some pharmaceuticals of concern for the aquatic environment and their relative importance compared with other chemicals.

    Science.gov (United States)

    Donnachie, Rachel L; Johnson, Andrew C; Sumpter, John P

    2016-04-01

    Aquatic organisms can be exposed to thousands of chemicals discharged by the human population. Many of these chemicals are considered disruptive to aquatic wildlife, and the literature on the impacts of these chemicals grows daily. However, because time and resources are not infinite, research must focus on the chemicals that represent the greatest threat. One group of chemicals of increasing concern is pharmaceuticals, for which the primary challenge is to identify which represent the greatest threat. In the present study, a list of 12 pharmaceuticals was compiled based on scoring the prevalence of different compounds from previous prioritization reviews. These included rankings based on prescription data, environmental concentrations, predicted environmental concentration/predicted no-effect concentration (PEC/PNEC) ratios, persistency/bioaccumulation/(eco)toxicity (PBT), and fish plasma model approaches. The most frequently cited were diclofenac, paracetamol, ibuprofen, carbamazepine, naproxen, atenolol, ethinyl estradiol, aspirin, fluoxetine, propranolol, metoprolol, and sulfamethoxazole. For each pharmaceutical, literature on effect concentrations was compiled and compared with river concentrations in the United Kingdom. The pharmaceuticals were ranked by degree of difference between the median effect and median river concentrations. Ethinyl estradiol was ranked as the highest concern, followed by fluoxetine, propranolol, and paracetamol. The relative risk of these pharmaceuticals was compared with those of metals and some persistent organic pollutants. Pharmaceuticals appear to be less of a threat to aquatic organisms than some metals (Cu, Al, Zn) and triclosan, using this ranking approach.

  3. Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL

    Science.gov (United States)

    Al-Hamdan, Mohammad; Estes, Maurice G., Jr.; Judd, Chaeli; Woodruff, Dana; Ellis, Jean; Quattrochi, Dale; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

    2012-01-01

    Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA s EcoWatch and Gulf of Mexico Data Atlas online systems for

  4. Development of advanced process-based model towards evaluation of boundless biogeochemical cycles in terrestrial-aquatic continuum

    Science.gov (United States)

    Nakayama, Tadanobu; Maksyutov, Shamil

    2014-05-01

    Recent research shows inland water may play some role in continental biogeochemical cycling though its contribution has remained uncertain due to a paucity of data (Battin et al. 2009). The author has developed process-based National Integrated Catchment-based Eco-hydrology (NICE) model (Nakayama, 2008a-b, 2010, 2011a-b, 2012a-c, 2013; Nakayama and Fujita, 2010; Nakayama and Hashimoto, 2011; Nakayama and Shankman, 2013a-b; Nakayama and Watanabe, 2004, 2006, 2008a-b; Nakayama et al., 2006, 2007, 2010, 2012), which incorporates surface-groundwater interactions, includes up- and down-scaling processes between local, regional and global scales, and can simulate iteratively nonlinear feedback between hydrologic, geomorphic, and ecological processes. In this study, NICE was extended to evaluate global hydrologic cycle by using various global datasets. The simulated result agreed reasonably with that in the previous research (Fan et al., 2013) and extended to clarify further eco-hydrological process in global scale. Then, NICE was further developed to incorporate the biogeochemical cycle including the reaction between inorganic and organic carbons (DOC, POC, DIC, pCO2, etc.) in the biosphere (terrestrial and aquatic ecosystems including surface water and groundwater). The model simulated the carbon cycle, for example, CO2 evasion from inland water in global scale, which is relatively in good agreement in that estimated by empirical relation using the previous pCO2 data (Aufdenkampe et al., 2011; Global River Chemistry Database, 2013). This simulation system would play important role in identification of full greenhouse gas balance of the biosphere and spatio-temporal hot spots in boundless biogeochemical cycle (Cole et al. 2007; Frei et al. 2012). References; Aufdenkampe, A.K., et al., Front. Ecol. Environ., doi:10.1890/100014, 2011. Battin, T.J., et al., Nat. Geosci., 2, 598-600, 2009. Cole, J.J. et al., Ecosystems, doi:10.1007/s10021-006-9013-8, 2007. Fan, Y. et al

  5. Contrasting PCB bioaccumulation patterns among Lake Huron lake trout reflect basin-specific ecology.

    Science.gov (United States)

    Paterson, Gordon; Ryder, Mark; Drouillard, Ken G; Haffner, G Douglas

    2016-01-01

    This study collected multiple age classes of lake trout from Lake Huron's Main Basin, Georgian Bay, and North Channel regions to compare and contrast top predator polychlorinated biphenyl (PCB) bioaccumulation patterns in separate compartments of the same ecosystem. Sum PCB concentrations were highest for Main Basin (260 ± 24.9 ng g(-1) wet wt) fish, followed by Georgian Bay (74.6 ± 16.2 ng g(-1) ) and North Channel (42.0 ± 3.3 ng g(-1)) fish. Discriminant functions analysis of lake trout PCB profiles and stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope values clearly distinguished fish by location, indicating high degrees of basin fidelity throughout their lifetimes in addition to highly contrasting PCB bioaccumulation profiles. These unique profiles were not attributable to significant differences in lake trout lipid contents (p = 0.856) or trophic position (δ(15)N; p = 0.334), with rainbow smelt representing the primary prey across the basins. Furthermore, significant differences were observed among the basins for the relationships between PCB biomagnification factors and hydrophobicity. An empirical model for predicting PCB biomagnification in Lake Huron lake trout indicated that basin-specific population growth rates and prey abundances were significant for explaining these contrasting patterns of PCB bioaccumulation. The results of the present study are fundamental for understanding the role of ecology in legacy persistent organic pollutant (POP) bioaccumulation. Specifically, ecosystem characteristics such as prey abundances, foraging ecology, and ultimately consumer growth can regulate the variability of legacy POP bioaccumulation as observed within and among a wide range of freshwater ecosystems.

  6. Toxicity and bioaccumulation of biosolids-borne triclocarban (TCC) in terrestrial organisms.

    Science.gov (United States)

    Snyder, Elizabeth Hodges; O'Connor, George A; McAvoy, Drew C

    2011-01-01

    Triclocarban (TCC) toxicity and bioaccumulation data are primarily limited to direct human and animal dermal exposures, animal ingestion exposures to neat and feed-spiked TCC, and/or aquatic organism exposures. Three non-human, terrestrial organism groups anticipated to be the most highly exposed to land-applied, biosolids-borne TCC are soil microbes, earthworms, and plants. The three ecological receptors are expected to be at particular risk due to unique modes of exposure (e.g. constant, direct contact with soil; uptake of amended soil and pore water), inherently greater sensitivity to environmental contaminants (e.g. increased body burdens, permeable membranes), and susceptibility to minute changes in the soil environment. The toxicities of biosolids-borne TCC to Eisenia fetida earthworms and soil microbial communities were characterized using adaptations of the USEPA Office of Prevention, Pesticides, and Toxic Substances (OPPTS) Guidelines 850.6200 (Earthworm Subchronic Toxicity Test) and 850.5100 (Soil Microbial Community Toxicity Test), respectively. The resultant calculated TCC LC50 value for E. fetida was 40 mg TCC kg amended fine sand(-1). Biosolids-borne TCC in an amended fine sand had no significant effect on soil microbial community respiration, ammonification, or nitrification. Bioaccumulation of biosolids-borne TCC by E. fetida and Paspulum notatum was measured to characterize potential biosolids-borne TCC movement through the food chain. Dry-weight TCC bioaccumulation factor (BAF) values in E. fetida and P. notatum ranged from 5.2-18 and 0.00041-0.007 (gsoil gtissue(-1)), respectively.

  7. Hot Spots of Mercury Bioaccumulation in Amphibian Populations From the Conterminous United States

    Science.gov (United States)

    Bank, M. S.

    2008-12-01

    Mercury (Hg) contamination in the United States (U.S.) is well-documented and continues to be a public- health issue of great concern. Fish consumption advisories have been issued throughout much of the U.S. due to elevated levels of methylmercury (MeHg). Methylmercury contamination in the developing fetus and in young children is a major public health issue for certain sectors of the global human population. Moreover, identifying MeHg hot spots and the effects of MeHg pollution on environmental health and biodiversity are also considered a high priority for land managers, risk assessors, and conservation scientists. Despite their overall biomass and importance to aquatic and terrestrial ecosystems, Hg and MeHg bioaccumulation dynamics and toxicity in amphibians are not well studied, especially when compared to other vertebrate taxa such as birds, mammals, and fish species. Population declines in amphibians are well documented and likely caused by synergistic and interacting, multiple stressors such as climate change, exposure to toxic pollutants, fungal pathogens, and habitat loss and ecosystem degradation. Protecting quality of terrestrial ecosystems in the U.S. has enormous ramifications for economic and public health of the nation's residents and is fundamental to maintaining the biotic integrity of surface waters, riparian zones, and environmental health of forested landscapes nationwide. Determining Hg concentration levels for terrestrial and surface water ecosystems also has important implications for protecting the nation's fauna. Here I present an overview of the National Amphibian Mercury Program and evaluate variation in MeHg hotspots, Hg bioaccumulation and distribution in freshwater and terrestrial habitats across a broad gradient of physical, climatic, biotic, and ecosystem settings to identify the environmental conditions and ecosystem types that are most sensitive to Hg pollution. The role of geography, disturbance mechanisms, and abiotic and biotic

  8. Bioaccumulation of metals in sediments, fish and plant from Tisza river (Serbia)

    Science.gov (United States)

    Štrbac, Snežana; Gajica, Gordana; Kašanin-Grubin, Milica; Šajnović, Aleksandra; Vasić, Nebojša; Jovančićević, Branimir; Simonović, Predrag

    2014-05-01

    In the aquatic environments metals originate from various natural and anthropogenic sources. The purpose of the study was to assess the bioaccumulation level of metals in sediments fish and common reed at four different localities of the Tisza River stretch in Serbia. For purpose of this study concentrations of Al, As, B, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr and Zn were determined in sediment, common reed (Phragmites australis (Cav.) Trin. ex Steud. 1841) and four ecologically different fish species (piscivorous northern pike (Esox lucius L.), benthivorous sterlet (Acipenser ruthenus L.) silver bream (Brama brama L.), omnivorous common carp (Cyprinus carpio L.)). Analysis of metals was carried out for liver, gills, brain, testicles and ovaries in fish and in the rhizome, stem and leaves of the common reed and sediment fraction leaves>stems. Obtained results indicate that the location does not have impact to the level of bioaccumulation. On the basis of this research the under-ground organ (rhizome) of common reed, liver and gills and omnivorous fish species could be recommended as environmental indicators for the presence of metals during environmental monitoring.

  9. Antioxidative responses and bioaccumulation in Japanese flounder larvae and juveniles under chronic mercury exposure.

    Science.gov (United States)

    Huang, Wei; Cao, Liang; Ye, Zhenjiang; Yin, Xuebo; Dou, Shuozeng

    2010-06-01

    This study investigated the sub-lethal effects of waterborne mercury on growth, bioaccumulation and antioxidative responses of larvae and juveniles of Japanese flounder (Paralichthys olivaceus). Fish were exposed to 0-10 microg Hg(2)(+)L(-1) solutions from embryonic to the juvenile stages for 80 days. Antioxidative responses to mercury exposure were studied in metamorphosing larvae (18 days post hatching, dph), settling larvae (33 dph) and juveniles (78 dph). Results showed that increasing mercury concentration led to increased mercury bioaccumulation and reduced flounder growth. Of the antioxidants investigated, superoxide dismutase (SOD) and catalase (CAT) activities at the three developmental stages were sensitive to mercury exposure and increased with increasing mercury concentration. Glutathione (GSH) content was elevated in metamorphosing larvae, but decreased in juveniles as mercury concentration increased. Glutathione-S-transferase (GST) activity did not significantly vary with mercury concentration in either larvae or juveniles. Mercury exposure did not affect malondialdehyde (MDA) content of larvae, but significantly increased MDA content of juveniles. Results suggest that flounder larvae and juveniles have the potential to manipulate the levels of antioxidants such as SOD, CAT and GSH, which protect flounder from oxidative stress induced by mercury exposure. These antioxidants could serve as biomarkers of mercury contamination in the aquatic environment.

  10. Evaluating the risk to aquatic ecosystems posed by leachate from tire shred fill in roads using toxicity tests, toxicity identification evaluations, and groundwater modeling.

    Science.gov (United States)

    Sheehan, Patrick J; Warmerdam, John M; Ogle, Scott; Humphrey, Dana N; Patenaude, Stacey M

    2006-02-01

    The risk to adjacent aquatic systems posed by leachates from scrap tires used in engineering applications has not been characterized adequately. Toxicity testing, toxicity identification evaluation (TIE), and groundwater modeling were used to determine the circumstances under which tire shreds could be used as roadbed fill with negligible risk to aquatic organisms in adjacent water bodies. Elevated levels of iron, manganese, and several other chemicals were found in tire shred leachates. However, chronic toxicity tests with Ceriodaphnia dubia and fathead minnows (Pimephales promelas) showed no adverse effects caused by leachates collected from tire shreds installed above the water table. Exposure to leachates collected from tire shreds installed below the water table resulted in significant reductions to both survival and reproduction in C. dubia. The TIE results indicated that exposure to soluble metals (likely ferrous iron primarily) and the formation of iron hydroxide precipitates on this invertebrate species likely were the causes of the observed effects. The available chemistry data show that iron concentrations in the affected groundwater decreased substantially within a short distance (0.61 m) downgradient of tire shred fill. Based on geochemical modeling, the use of tire shreds in applications below the water table is appropriate in settings where dissolved oxygen is greater than 2.0 mg/L, pH is greater than 5.8, and a downgradient buffer of approximately 3.0 m exists between the fill and the surface water. For settings with lower dissolved oxygen concentrations or lower pH, results of groundwater modeling indicate that a greater buffer distance (approximately 11 m) is needed to dilute the leachate to nontoxic levels under various soil and groundwater conditions solely through advection and dispersion processes. PMID:16519300

  11. Bioaccumulation and transformation of cadmium by Phaeodactylum tricornutum

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper,we report the bioaccumulation and transformation of cadmium (Cd) by Phaeodactylum tricornutum in the presence of ethylenediamine tetra acetic acid (EDTA) and cysteine (Cys). Both EDTA and Cys can alleviate the toxicity of Cd to P. tricornutum. Short term intracellular uptake and extracellular adsorption experiments using ICP-MS indicated that the amounts of Cd accumulated on the cell surface of P. tricornutum and inside the cell decreased along with the increase of EDTA concentration,which conformed to the prediction of the Free Ion Activity Model (FIAM). However,extracellular adsorption of Cd increased at first and then decreased along with the increase in the concentration of Cys,while intracellular uptake increased under Cys concentrations from the blank value to 4.45 μmol/L,and then tended to remain at the same level when the Cys concentration was greater than 4.45 μmol/L,and this deviated remarkably from the FIAM. The interactions of Cd with _Si_OH,_C_OH and NH2(CO) _OH on the cell wall were confirmed using FT-IR and XPS studies. The results obtained using HPLC of the phytochelatins (PCs) produced by P. tricornutum under CdCl2,Cd_EDTA and Cd_Cys stress suggested that the main reason for the different effects of EDTA and Cys on the bioaccumulation and transformation of Cd by P. tricornutum was that Cys is not only a complexing ligand to Cd,as is EDTA,but also it is a precursor of the intracellular synthesizing PCs participating in the cellular defense mechanism against Cd. Furthermore,the discovery of in vivo PCs and oxidized_PCs as well as Cd-PC2 in P. tricornutum using ESI-IT-MS provided the evidence for deactivation of Cd by the PCs,reducing Cd-toxicity to P. tricornutum.

  12. A Method for Application of Classification Tree Models to Map Aquatic Vegetation Using Remotely Sensed Images from Different Sensors and Dates

    Directory of Open Access Journals (Sweden)

    Ying Cai

    2012-09-01

    Full Text Available In previous attempts to identify aquatic vegetation from remotely-sensed images using classification trees (CT, the images used to apply CT models to different times or locations necessarily originated from the same satellite sensor as that from which the original images used in model development came, greatly limiting the application of CT. We have developed an effective normalization method to improve the robustness of CT models when applied to images originating from different sensors and dates. A total of 965 ground-truth samples of aquatic vegetation types were obtained in 2009 and 2010 in Taihu Lake, China. Using relevant spectral indices (SI as classifiers, we manually developed a stable CT model structure and then applied a standard CT algorithm to obtain quantitative (optimal thresholds from 2009 ground-truth data and images from Landsat7-ETM+, HJ-1B-CCD, Landsat5-TM and ALOS-AVNIR-2 sensors. Optimal CT thresholds produced average classification accuracies of 78.1%, 84.7% and 74.0% for emergent vegetation, floating-leaf vegetation and submerged vegetation, respectively. However, the optimal CT thresholds for different sensor images differed from each other, with an average relative variation (RV of 6.40%. We developed and evaluated three new approaches to normalizing the images. The best-performing method (Method of 0.1% index scaling normalized the SI images using tailored percentages of extreme pixel values. Using the images normalized by Method of 0.1% index scaling, CT models for a particular sensor in which thresholds were replaced by those from the models developed for images originating from other sensors provided average classification accuracies of 76.0%, 82.8% and 68.9% for emergent vegetation, floating-leaf vegetation and submerged vegetation, respectively. Applying the CT models developed for normalized 2009 images to 2010 images resulted in high classification (78.0%–93.3% and overall (92.0%–93.1% accuracies. Our

  13. Aquatic Life Benchmarks

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Aquatic Life Benchmarks is an EPA-developed set of criteria for freshwater species. These benchmarks are based on toxicity values reviewed by EPA and used in...

  14. Aquatic Research Laboratory (ARL)

    Data.gov (United States)

    Federal Laboratory Consortium — Columbia River and groundwater well water sources are delivered to the Aquatic Research Laboratory (ARL), where these resources are used to conduct research on fish...

  15. Restoring Damaged Aquatic Ecosystems

    OpenAIRE

    Cairns, John

    2006-01-01

    Aquatic ecosystems must play a major role to ensure that water, which is both essential and scarce, is always available for both present and future generations. This has become even more urgent in light of the ongoing increase in total world population and predicted changes in the world climate. Since aquatic ecosystems have been damaged at a rate far in excess of both natural restoration and anthropogenic restoration, it is essential that both restorative processes be accelerated. However, e...

  16. Introducing Aquatic Biology

    OpenAIRE

    Kinne, Otto; Browman, Howard I.; Seaman, Matthias

    2007-01-01

    The Inter-Research Science Center (IR) journals Marine Ecology Progress Series (MEPS) and Aquatic Microbial Ecology (AME) have been receiving increasing numbers of high-quality manuscripts that are principally biological, rather than ecological. With regret, we have had to turn these submissions away. Also, leading limnologists have for many years suggested that IR should provide an outlet for top quality articles on freshwater biology and ecology. Aquatic Biology (...

  17. Molecular ecology of aquatic microbes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

  18. Using High-Resolution Models to Predict the Effects of Climate Change on Aquatic Ecosystems in the Crown of the Continent

    Science.gov (United States)

    Jones, L.; Muhlfeld, C.; Marshall, L. A.

    2013-12-01

    Climate trends and projections have prompted interest in assessing the thermal sensitivity of aquatic species. How species will adapt and respond to these changes is uncertain, however, climatic and hydrologic changes may shift species habitat distributions and physiological functions both spatially and temporally. This is particularly true for salmonids (e.g., trout, char, and salmon), which are cold-water species strongly influenced by changes in temperature, flow, and physical habitat conditions. Therefore, understanding how habitats are likely to change and how species may respond to changes in climatic conditions is critical for developing conservation and management strategies. The purpose of this study is to develop a high-resolution stream temperature model for the Crown of the Continent Ecosystem (CCE) to simulate potential climate change impacts on thermal regimes throughout the riverscape. A spatially explicit statistical regression model is coupled with high-resolution climate data such as air temperature, precipitation, solar radiation, baseflow and surface runoff. This empirically based model is used to predict daily stream temperatures under historic, current and forecasted climate conditions. The model is parameterized with empirical stream temperature data, which has been gathered from agencies across the region. The current database of empirical stream temperature data consists of over 800 sites throughout the CCE, which provide time series data to the model application. The biological integration and application of this model is on bull trout (Salvelinus confluentus) populations within the CCE. The model will be used to assess species vulnerabilities caused by spatial and temporal changes in stream temperature and hydrology. By evaluating the magnitude, timing and duration of climatic changes on the riverscape, we can more accurately assess potential vulnerabilities of critical life history traits, such as growth potential, spawning migrations

  19. Elemental bioaccumulators in air pollution studies

    International Nuclear Information System (INIS)

    K0-Based instrumental neutron activation analysis (k0 INAA) was used to determine the concentrations of Cr, Fe, Co, Zn, Se, Sb and Hg in the vascular plants Cistus salvifolius and Inula viscosa and in the lichen Parmelia sulcata. The samples were collected in the neighbourhood of industrial complexes. The elemental accumulation in the vascular plants and the lichen are compared to optimize the choice of the bioaccumulator. It is concluded that P.sulcata seems to be the best accumulator of the three species for the element studied; Cistus salvifolius is sensitive to the contents of Zn, Fe, Cr and Sb in the air; Inula viscosa seems to accumulate Fe, Sb, Co, Cr and Zn. Nevertheless, it is concluded that lichen is a good air pollution indicator, while the vascular plants are not due to the large seasonal variations found in the elemental concentrations. (author) 11 refs.; 7 figs.; 2 tabs

  20. A protocell design for bioaccumulation applications

    CERN Document Server

    von Hegner, Ian

    2015-01-01

    This article provides a specific example of recombinant cell and protocell technology, moving from what is presently known to suggesting how novel application of existing methodologies could be utilized to design a complex synthetic system in form of a self-sufficient light empowered protocell. A practical application of protocells using a primary example of desalination in water treatment is given, followed by a more general approach to bioaccumulation and bio-diagnostics, outlining the possibilities associated with applications of protocells. The key hypothesis is that the inside-negative electrochemical membrane potential generated by chloride pump activity via halorhodopsin could also be utilized to drive the accumulation of cations into a protocell. Thus, the functional expression of halorhodopsin could energize proton-coupled uptake of substances or metals through a selective cotransport channel for a number of applications in biotechnology, molecular medicine, and water biotechnology.

  1. Bioaccumulation and ecotoxicity of carbon nanotubes

    DEFF Research Database (Denmark)

    Jackson, Petra; Jacobsen, Nicklas Raun; Baun, Anders;

    2013-01-01

    Carbon nanotubes (CNT) have numerous industrial applications and may be released to the environment. In the aquatic environment, pristine or functionalized CNT have different dispersion behavior, potentially leading to different risks of exposure along the water column. Data included in this review...

  2. The Japanese medaka (Oryzias latipes) model: applicability for investigating the immunosuppressive effects of the aquatic pollutant benzo[a]pyrene (BaP).

    Science.gov (United States)

    Carlson, E A; Li, Y; Zelikoff, J T

    2002-01-01

    Despite the fact that BaP is a carcinogen, mammalian immunosuppressant, and ubiquitous aquatic pollutant, knowledge regarding the effects of BaP on the immune system of fish is still lacking. To begin to fill this gap, studies were conducted in medaka to examine the effects and mechanisms by which BaP exposure might alter host immunocompetence. Fish, exposed by IP injection of BaP (2-600 microg/g BW), were examined after 48 h for effects upon immune function and CYP1A expression/activity. Benzo[a]pyrene, at a concentration below that which increased levels of CYPIA expression/activity (2 microg BaP/g BW) suppressed lymphocyte proliferation. Concentrations of BaP at 20 and 200 microg/g BW. suppressed antibody-forming cell (AFC) numbers, superoxide production, and host resistance against bacteria. In contrast, exposure to the low affinity aryl hydrocarbon receptor (AhR) agonist, benzo[e]pyrene (BeP), neither induced CYP1A expression nor altered immune function. Given the lack of immunosuppressive effects produced by BeP, and the fact that exposure to the AhR antagonist (and CYP1A inhibitor) alpha-naphthoflavone (ANF) ameliorated the suppressive effects of BaP upon AFC numbers, the AhR pathway (including CYP1A-mediated production of reactive BaP metabolites) appears important in mediating BaP-induced immunotoxicity in fish, as in mammals. In the past, the medaka has proven a successful model for assessing carcinogenic agents. These studies have demonstrated its utility for also determining the immunosuppressive effects of an important aquatic contaminant.

  3. Predicting the bioaccumulation of polyaromatic hydrocarbons and polychlorinated biphenyls in benthic animals in sediments.

    Science.gov (United States)

    Tuikka, A I; Leppänen, M T; Akkanen, J; Sormunen, A J; Leonards, P E G; van Hattum, B; van Vliet, L A; Brack, W; Smedes, F; Kukkonen, J V K

    2016-09-01

    There were two main objectives in this study. The first was to compare the accuracy of different prediction methods for the chemical concentrations of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the organism, based on the measured chemical concentrations existing in sediment dry matter or pore water. The predicted tissue concentrations were compared to the measured ones after 28-day laboratory test using oligochaeta worms (Lumbriculus variegatus). The second objective was to compare the bioaccumulation of PAHs and PCBs in the laboratory test with the in situ bioaccumulation of these compounds. Using the traditional organic carbon-water partitioning model, tissue concentrations were greatly overestimated, based on the concentrations in the sediment dry matter. Use of an additional correction factor for black carbon with a two-carbon model, significantly improved the bioaccumulation predictions, thus confirming that black carbon was important in binding the chemicals and reducing their accumulation. The predicted PAH tissue concentrations were, however, high compared to the observed values. The chemical concentrations were most accurately predicted from their freely dissolved pore water concentrations, determined using equilibrium passive sampling. The patterns of PCB and PAH accumulation in sediments for laboratory-exposed L. variegatus were similar to those in field-collected Lumbriculidae worms. Field-collected benthic invertebrates and L. variegatus accumulated less PAHs than PCBs with similar lipophilicity. The biota to sediment accumulation factors of PAHs tended to decrease with increasing sediment organic carbon normalized concentrations. The presented data yields bioconcentration factors (BCF) describing the chemical water-lipid partition, which were found to be higher than the octanol-water partition coefficients, but on a similar level with BCFs drawn from relevant literature. In conclusion, using the two-carbon model method

  4. In situ Treatment with Activated Carbon Reduces Bioaccumulation in Aquatic Food Chains

    NARCIS (Netherlands)

    Kupryianchyk, D.; Rakowska, M.I.; Roessink, I.; Reichman, E.P.; Grotenhuis, J.T.C.; Koelmans, A.A.

    2013-01-01

    In situ activated carbon (AC) amendment is a new direction in contaminated sediment management, yet its effectiveness and safety have never been tested on the level of entire food chains including fish. Here we tested the effects of three different AC treatments on hydrophobic organic chemical (HOC)

  5. In situ treatment with activated carbon reduces bioaccumulation in aquatic food chains.

    Science.gov (United States)

    Kupryianchyk, D; Rakowska, M I; Roessink, I; Reichman, E P; Grotenhuis, J T C; Koelmans, A A

    2013-05-01

    In situ activated carbon (AC) amendment is a new direction in contaminated sediment management, yet its effectiveness and safety have never been tested on the level of entire food chains including fish. Here we tested the effects of three different AC treatments on hydrophobic organic chemical (HOC) concentrations in pore water, benthic invertebrates, zooplankton, and fish (Leuciscus idus melanotus). AC treatments were mixing with powdered AC (PAC), mixing with granular AC (GAC), and addition-removal of GAC (sediment stripping). The AC treatments resulted in a significant decrease in HOC concentrations in pore water, benthic invertebrates, zooplankton, macrophytes, and fish. In 6 months, PAC treatment caused a reduction of accumulation of polychlorobiphenyls (PCB) in fish by a factor of 20, bringing pollutant levels below toxic thresholds. All AC treatments supported growth of fish, but growth was inhibited in the PAC treatment, which was likely explained by reduced nutrient concentrations, resulting in lower zooplankton (i.e., food) densities for the fish. PAC treatment may be advised for sites where immediate ecosystem protection is required. GAC treatment may be equally effective in the longer term and may be adequate for vulnerable ecosystems where longer-term protection suffices. PMID:23544454

  6. Influence of feeding and earthworm density on compound bioaccumulation in earthworms Eisenia andrei.

    Science.gov (United States)

    Šmídová, Klára; Šerá, Jana; Bielská, Lucie; Hofman, Jakub

    2015-12-01

    Earthworm density and feeding during exposure to contaminated soil have been used inconsistently in bioaccumulation studies, which may lead to possible errors in risk assessment and modeling. Hydrophobic organic pollutants with a wide range of environmental properties (phenanthrene, pyrene, lindane, p,p'-DDT, and PCB 153) were used to study the effect of different earthworm densities in combination with the presence or absence of feeding on bioaccumulation factors (BAFs). Similar BAFs were found at various soil-to-worm ratios, with the exception of phenanthrene. We recommend using at least 15 gsoil dw per earthworm. The absence of feeding doubled the BAFs and, thus, using no food ration can be considered as "the worst case scenario". Whenever food is to be applied (i.e. to ensure the validity of the test in earthworm mass loss), we suggest feeding depending on the organic carbon content of the studied soil. PMID:26378968

  7. [Dissolution, absorption and bioaccumulation in gastrointestinal tract of mercury in HgS-containing traditional medicines Cinnabar and Zuotai].

    Science.gov (United States)

    Zheng, Zhi-yuan; Li, Cen; Zhang, Ming; Yang, Hong-xia; Geng, Lu-jing; Li, Lin-shuai; Du, Yu-zhi; Wei, Li-xin

    2015-06-01

    α-HgS is the main component of traditional Chinese medicine cinnabar, while β-HgS is the main component of Tibetan medicine Zuotai. However, there was no comparative study on the dissolution and absorption in gastrointestinal tract and bioaccumulation in organs of mercury in Cinnabar, Zuotai, α-HgS and β-HgS. In this study, the dissolution process of the four compounds in the human gastrointestinal tract was simulated to determine the mercury dissolutions and compare the mercury dissolution of different medicines and the dissolution-promoting capacity of different solutions. To explore the absorption and bioaccumulation of cinnabar and Zuotai in organisms, mice were orally administered with clinical equivalent doses cinnabar and Zuotai. Meanwhile, a group of mice was given α-HgS and β-HgS with the equivalent mercury with cinnabar, while another group was given β-HgS and HgCl2 with the equivalent mercury with Zuotai. The mercury absorption and bioaccumulation capacities of different medicines in mice and their mercury bioaccumulation in different tissues and organs were compared. The experimental results showed a high mercury dissolutions of Zuotai in artificial gastrointestinal fluid, which was followed by β-HgS, cinnabar and α-HgS. As for the mercury absorption and bioaccumulation in mice, HgCl2 was the highest, β-HgS was the next, and a-HgS was slightly higher than cinnabar. The organs with the mercury bioaccumulation from high to low were kidney, liver and brain. This study is close to clinical practices and can provide reference for the clinical safe medication as well as a study model for the safety evaluation on heavy metal-containing medicines by observing the mercury dissolution, absorption, distribution and accumulation of mercury-containing medicines cinnabar and zuotai. PMID:26591542

  8. BIOACCUMULATION OF HEAVY METALS BY BACILLUS MEGATERIUM FROM PHOSPHOGYPSUM WASTE

    Directory of Open Access Journals (Sweden)

    IOANA ADRIANA STEFANESCU

    2015-05-01

    Full Text Available The aim of present study was to characterize the bioaccumulation capacity of heavy metals by Bacillus megaterium from phosphogypsum waste. The Bacillus megaterium strain (BM30 was isolated from soil near the phosphogypsum (PG dump. For the bioaccumulation quantification produced by BM30 strain were used three experimental treatments respectively with 2, 6 and 10 gL-1 PG. Cellular biomass samples were collected punctually at ages corresponding to the three stages of the development cycle of the microorganism: exponential phase, stationary phase and decline phase and the heavy metals concentrations were measured by atomic absorption spectroscopy. The bioaccumulation yields in cell biomass, relative to the total amount of analyte introduced in the reaction medium were between 20 - 80 %, the lowest value was recorded by Cu and highest by Mn. The study results indicated that the isolated strain near the dump PG, BM30, bioaccumulate heavy metals monitored in cell biomass in the order Cu > Fe > Zn = Mn.

  9. Bioaccumulation dynamics of polychlorinated biphenyls (PCBs) and organochlorine pesticides

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bioaccumulation dynamics of polychlorinated biphenyls (PCBs) and organochlorine pesticides was examined in young-of-the-year bluefish from seven sub-estuaries of...

  10. Impact of Organic Contamination on Some Aquatic Organisms

    OpenAIRE

    Yasser, El-Nahhal; Shawkat, El-Najjar; Samir, Afifi

    2015-01-01

    Background: Contamination of water systems with organic compounds of agricultural uses pose threats to aquatic organisms. Carbaryl, chlorpyrifos, and diuron were considered as model aquatic pollutants in this study. The main objective of this study was to characterize the toxicity of organic contamination to two different aquatic organisms. Materials and Methods: Low concentrations (0.0–60 µmol/L) of carbaryl, diuron and very low concentration (0.0–0.14 µmol/L) of chlorpyrifos and their mixtu...

  11. Global N removal by freshwater aquatic systems using a spatially distributed, within-basin approach

    NARCIS (Netherlands)

    Wollheim, W.M.; Vörösmarty, C.J.; Bouwman, A.F.; Green, P.; Harrison, J.; Linder, E.; Peterson, B.J.; Seitzinger, S.P.; Syvitski, J.P.M.

    2008-01-01

    We explored the role of aquatic systems in the global N cycle using a spatially distributed, within-basin, aquatic nitrogen (N) removal model, implemented within the Framework for Aquatic Modeling in the Earth System (FrAMES-N). The model predicts mean annual total N (TN) removal by small rivers (wi

  12. Proceedings of the twentieth annual aquatic toxicity workshop. Comptes rendus du vingtieme colloque annuel de toxicologie aquatique

    Energy Technology Data Exchange (ETDEWEB)

    Coillie, R. van; Roy, Y.; Bois, Y.; Campbell, P.G.C.; Lundahl, P.; Martel, L.; Michaud, M.; Riebel, P.; Thellen, C. (eds.)

    1994-01-01

    A workshop was held as part of a continuing series of meetings on toxicity testing methods and pathways of contaminants in the aquatic environment. Papers were presented at the workshop on topics including biodegradation of contaminants, ecological assessments of priority substances, micro-scale bioassays, mercury in the northern aquatic environment, ecotoxicological risk assessment, bioaccumulation of contaminants, effects assessment, the St. Lawrence River Action Plan, polycyclic aromatic hydrocarbons, industrial effluents and environment management, microcosms and mesocosms, and biomarkers. Separate abstracts have been prepared for five papers from this workshop.

  13. Modeling and optimization of anaerobic codigestion of potato waste and aquatic weed by response surface methodology and artificial neural network coupled genetic algorithm.

    Science.gov (United States)

    Jacob, Samuel; Banerjee, Rintu

    2016-08-01

    A novel approach to overcome the acidification problem has been attempted in the present study by codigesting industrial potato waste (PW) with Pistia stratiotes (PS, an aquatic weed). The effectiveness of codigestion of the weed and PW was tested in an equal (1:1) proportion by weight with substrate concentration of 5g total solid (TS)/L (2.5gPW+2.5gPS) which resulted in enhancement of methane yield by 76.45% as compared to monodigestion of PW with a positive synergistic effect. Optimization of process parameters was conducted using central composite design (CCD) based response surface methodology (RSM) and artificial neural network (ANN) coupled genetic algorithm (GA) model. Upon comparison of these two optimization techniques, ANN-GA model obtained through feed forward back propagation methodology was found to be efficient and yielded 447.4±21.43LCH4/kgVSfed (0.279gCH4/kgCODvs) which is 6% higher as compared to the CCD-RSM based approach. PMID:27155267

  14. Bioaccumulation of Fe2O3(magnetic) nanoparticles in Ceriodaphnia dubia

    International Nuclear Information System (INIS)

    While nano-Fe2O3(magnetic) is generally considered non-toxic, it could serve as a carrier of other toxic chemicals such as As(V) and enhance their toxicity. The bioaccumulation of nano-Fe2O3(m) with different exposure times, NP concentrations, and pH conditions was investigated using Ceriodaphnia dubia (C. dubia) as the model organism. Under natural pH conditions, C. dubia significantly accumulated nano-Fe2O3(m) in the gut, with the maximum accumulation being achieved after 6 h of exposure. The concentration of nano-Fe2O3 also impacted its accumulation, with the maximum uptake occurring at 20 mg/L or more. In addition, the highest bioaccumulation occurred in a pH range of 7–8 where the highest feeding rate was reported, confirming that the ingestion of NPs is the main route of nano-Fe2O3(m) bioaccumulation. In a clean environment without NPs, depuration of nano-Fe2O3(m) occurred, and food addition accelerated the depuration process. - Highlights: ► Nano-Fe2O3(m) enhances the toxicity of As(V). ► C. dubia significantly accumulate nano-Fe2O3(m) through ingestion. ► The bioaccumulation of nano-Fe2O3(m) is affected by time, NP concentration, and pH. ► Food addition accelerates the depuration process of accumulated nano-Fe2O3(m). - Nano-Fe2O3(m) could enhance the toxicity of As(V) due to the significant accumulation of nano-Fe2O3(m) along with sorbed As(V) by C. dubia through ingestion.

  15. Which processes dominate the uncertainties in the modelling of the transfer of radionuclides in lake ecosystems

    International Nuclear Information System (INIS)

    There are several processes governing the transfer of radionuclides in the aquatic environment. These processes are usually lumped together into specific parameters describing those processes, such as distribution coefficients and bioaccumulation factors. One can conclude from the B3 scenario that the differences in results were explained more by difference in the selection of parameter values than they were by differences in assumed lake type or model structure. The parameters contributing most to the uncertainty in model predictions were the distribution coefficient between water and sediment and the fish bioaccumulation factor. In a site specific assessment it may be possible to limit the level of consideration necessary for each process according to lake type, the chemical and physical characteristics of the radionuclides released. In the B5 scenario it was found that no new processes were identified in spite of the site specific data given. However most users changed their model according to the new information given. The A5 scenario showed that the predictions were in fairly good agreement with the observed values. Other results from this study are the importance of including resuspension, chemical form. Predictions of concentration of cesium in fish were performed by applying a constant bioaccumulation factor approach or a dynamic modelling approach. It showed that it was necessary to apply the dynamic modelling to be able to calculate the initial concentration in fish. This was also discussed in Scenario B3 and thus has been verified in Scenario A5. (3 refs., 10 figs.)

  16. Combined effects of sugarcane bagasse extract and synthetic dyes on the growth and bioaccumulation properties of Pichia fermentans MTCC 189.

    Science.gov (United States)

    Das, Devlina; Charumathi, D; Das, Nilanjana

    2010-11-15

    Bioaccumulation of synthetic dyes viz. Acid Blue 93, Direct Red 28 and Basic Violet 3 by growing cells of yeast, Pichia fermentans MTCC 189 was investigated in growth media prepared from sugarcane bagasse extract. The maximum dye bioaccumulation was determined at pH 5.0 for all the dyes tested. Two kinetic models viz. Noncompetitive and Uncompetitive models were tested in order to determine the toxic effects of dyes on the specific growth rate of P. fermentans MTCC 189. Basic Violet 3 was found to be more toxic than the other two dyes. The combined effects of sugarcane bagasse extract and initial Basic Violet 3 dye concentrations on the specific growth rate and dye bioaccumulation efficiency of P. fermentans MTCC 189 was investigated and optimized using Response Surface Methodology (RSM). A 2(2) full factorial central composite design was successfully used for analysis of results. The optimum combination predicted via RSM confirmed that P. fermentans MTCC 189 was capable of bioaccumulating Basic Violet 3 dye upto 69.8% in the medium containing 10 mg/L of dye and 24 g/L sugar extracted from sugarcane bagasse.

  17. Contaminated Aquatic Sediments.

    Science.gov (United States)

    Jaglal, Kendrick

    2016-10-01

    A review of the literature published in 2015 relating to the assessment, evaluation and remediation of contaminated aquatic sediments is presented. The review is divided into the following main sections: policy and guidance, methodology, distribution, fate and transport, risk, toxicity and remediation. PMID:27620103

  18. Aquatic Environment 2000

    DEFF Research Database (Denmark)

    Svendsen, L. M.; Bijl, L. van der; Boutrup, S.;

    The report summarizes the results of the Danish Aquatic Monitoring and Assessment Programme 1998-2003. Danish Environmental Protection Agency 2000: NOVA-2003. Programbeskrivelse for det nationale program for overvågning af vandmiljøet 1998-2003. 397 pp. - Redegørelse fra Miljøstyrelsen nr. 1 (in...

  19. Assessing the concentrations of polar organic microcontaminants from point sources in the aquatic environment: measure or model?

    Science.gov (United States)

    Johnson, Andrew C; Ternes, Thomas; Williams, Richard J; Sumpter, John P

    2008-08-01

    To carry out meaningful ecotoxicity studies on novel polar organic microcontaminants, it is essential to know what concentrations wildlife may be exposed to. Traditionally these values were obtained by analytical chemistry, but in recent years GIS water quality models have been developed which may offer a quick and reliable way of getting the same information. Thus, two ways of obtaining basically the same information now exist, and an issue, therefore, arises as to which method is the most appropriate to use in which situation. To address this issue we have critically reviewed and compared measuring and modeling approaches for the determination of sewage effluent and river water concentrations of organic microcontaminants. Where model predictions and chemical measurements can be directly compared in sewage effluents, receiving waters, and across catchments, reported model mean values have all been within 1 order of magnitude of the measured values, with typically no more than a 3- or 4-fold difference. Interlaboratory chemical analysis of some organic microcontaminants in effluents in the challenging ng/L range have provided results which have varied from one another by a similar margin. No such comparison has been carried out yet for GIS water quality models to determine variation in predicted concentrations. As the level of ecotoxicological effects of many chemicals is often considerably higher than the reported measured or modeled values, such errors that might occur will often be of no consequence. But due to their extraordinary potency, much more accuracy is required with some natural and synthetic hormones. Significantly, modeling is no more complex to conduct when dealing with contaminants at ng/L compared with mg/L concentrations, but the same cannot be said for chemical analysis. A combination of modeling and measuring techniques will give the greatest confidence in risk assessment. PMID:18754451

  20. LiDAR-derived spatial models of hydrological and biogeochemical source areas to improve estimates of terrestrial-aquatic mercury export in northern forested landscapes

    Science.gov (United States)

    Richardson, M. C.; Mitchell, C. P.; Branfireun, B. A.; Kolka, R. K.; Fortin, M.

    2010-12-01

    Recent research on watershed mercury (Hg) and dissolved organic carbon (DOC) cycling in headwater research catchments in south-central Ontario, northwestern Ontario and northern Minnesota points to the critical role of discrete landscape elements in dictating rainfall-runoff response and the mobilization of DOC, Hg and methyl-mercury (MeHg) to downstream surface-waters. An overview of this research will be presented, emphasising two newly developed techniques used to extract hydrological and biogeochemical sources areas from airborne Light Detection and Ranging (LiDAR) surveys. First, hydrogeomorphic edge-detection was used to partition the landscape into discrete functional units based on local drainage conditions. From this initial landscape segmentation, forested wetlands and non-wetland saturation prone depressional areas were classified and extracted using classification and regression tree models based on LiDAR-derived geomorphic indices aggregated to the scale of individual landscape elements. Following this procedure, a characteristic morphology analysis was conducted from LiDAR bare-earth returns to quantitatively define the upland-peatland interfaces within all peatlands greater than 0.2 ha. These two terrain analysis techniques produced a number of functionally different landscape element classes that were subsequently used in the south-central Ontario study sites to test statistical models of terrestrial-aquatic fluxes of DOC, total Hg and MeHg over different time-scales. The regression models indicate that functional differences exist among landscape element classes with respect to their solute source-strengths and runoff generating potentials, and showed marked improvements over previous landscape models of hydrological and biogeochemical source areas in northern forested regions. LiDAR remote sensing can therefore be used to refine estimates of biogeochemical transformations and solute transport at the landscape scale, thus improving our

  1. Bioaccumulation of trace elements by Avicennia marina

    Directory of Open Access Journals (Sweden)

    Kandasamy Kathiresan

    2014-11-01

    Full Text Available Objective: To analyze the concentrations of 12 micro-nutrients (Al, B, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn in different plant parts of Avicennia marina and its rhizosphere soil of the south east coast of India. Methods: The samples were acid digested, then analyzed by using inductively coupled plasma system (ICP-Optical Emission Spectrophotometer. Results: Levels of metals were found in the decreasing order: Cd>Co>Ni>Pb>B >Cr>Zn>Mg>Mn>Cu>Fe>Al. The soil held more levels of metals than plant parts, but within the permissible limits of concentration. Bark and root accumulated higher levels of trace elements in a magnitude of 10-80 folds than other plant parts. The overall bioaccumulation factor in the sampling sites of Vellar, Pichavaram and Cuddalore was 2.88, 1.42 0.47 respectively. Essential elements accumulate high in mature mangroves forest while non-essential elements accumulate high in the industrially polluted mangroves. Conclusions: The ratio between essential and non-essential elements was found higher in young mangrove forest than that in mature mangrove forest and polluted mangrove areas. Thus, the ratio of accumulation can be used as an index of the growth and pollution status of mangroves.

  2. Bioaccumulation of trace elements by Avicennia marina

    Institute of Scientific and Technical Information of China (English)

    Kandasamy Kathiresan; Kandasamy Saravanakumar; Pandiyan Mullai

    2014-01-01

    Objective: To analyze the concentrations of 12 micro-nutrients (Al, B, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn) in different plant parts of Avicennia marina and its rhizosphere soil of the south east coast of India. Methods: The samples were acid digested, then analyzed by using inductively coupled plasma system (ICP-Optical Emission Spectrophotometer). Results: Levels of metals were found in the decreasing order: Cd>Co>Ni>Pb>B>Cr>Zn>Mg>Mn>Cu>Fe>Al. The soil held more levels of metals than plant parts, but within the permissible limits of concentration. Bark and root accumulated higher levels of trace elements in a magnitude of 10-80 folds than other plant parts. The overall bioaccumulation factor in the sampling sites of Vellar, Pichavaram and Cuddalore was 2.88, 1.42 0.47 respectively. Essential elements accumulate high in mature mangroves forest while non-essential elements accumulate high in the industrially polluted mangroves. Conclusions:The ratio between essential and non-essential elements was found higher in young mangrove forest than that in mature mangrove forest and polluted mangrove areas. Thus, the ratio of accumulation can be used as an index of the growth and pollution status of mangroves.

  3. Aquatic Pest Control. Manual 99.

    Science.gov (United States)

    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. Introduced aquatic plants and algae

    Science.gov (United States)

    Non-native aquatic plants such as waterhyacinth and hydrilla severely impair the uses of aquatic resources including recreational faculties (lakes, reservoirs, rivers) as well as timely delivery of irrigation water for agriculture. Costs associated with impacts and management of all types of aquatic...

  5. Potential of the aquatic fern Azolla filiculoides in biodegradation of an azo dye: modeling of experimental results by artificial neural networks.

    Science.gov (United States)

    Khataee, A R; Movafeghi, A; Vafaei, F; Lisar, S Y Salehi; Zarei, M

    2013-01-01

    The potential of an aquatic fern, Azolla filiculoides, in phytoremediation of a mono azo dye solution, C.I. Acid Blue 92 (AB92), was studied. The effects of operational parameters such as reaction time, initial dye concentration, fern fresh weight, pH, temperature and reusability of the fern on biodegradation efficiency were investigated. The intermediate compounds produced by biodegradation process were analyzed using GC-MS analysis. An artificial neural network (ANN) model was developed to predict the biodegradation efficiency. The findings indicated that ANN provides reasonable predictive performance (R2 = 0.961). The effects of AB92 solutions (10 and 20 mg L(-1)) on growth, chlorophylls and carotenoids content, activity of antioxidant enzymes such as superoxide dismutase, peroxidase and catalase and formation of malondialdehyde were analyzed. AB92 generally showed inhibitory effects on the growth. Moreover, photosynthetic pigments in the fronds significantly decreased in the treatments. An increase was detected for lipid peroxidation and antioxidant enzymes activity, suggesting that AB92 caused reactive oxygen species production in Azolla fronds, which were scavenged by induced activities of antioxidant enzymes. PMID:23819271

  6. Study on Cultivation Technique and Model Innovation of Aquatic Vegetables%浙江水生蔬菜栽培技术和模式的创新

    Institute of Scientific and Technical Information of China (English)

    郑寨生; 张尚法; 王凌云; 陈淑玲; 张雷; 袁名安; 孔向军

    2013-01-01

    通过水生蔬菜栽培技术和模式创新研究,先后总结出单季茭“一茬双收”栽培技术、双季茭“三改两优化”栽培技术、莲藕“五改”早熟栽培技术、子莲“早鲜多”栽培技术和菱角“带果移栽”长季栽培技术等,并在产区得到大面积推广,取得明显成效.%This paper summarized a series of cultivation techniques by researching on the cultivation technique and model innovation of aquatic vegetables, such as "One cropping and double harvest" of single - cropping water bamboo, "Three transformation and two optimization" of double - cropping water bamboo, "five transformation" of early maturing lotus root, "early maturity - fresh - high yield" of seed lotus, and "transplanting with immature fruit" long - season cultivation technique of water chestnut. These techniques obtained large - scale promotion in the production region, and achieved remarkable results.

  7. Potential of the aquatic fern Azolla filiculoides in biodegradation of an azo dye: modeling of experimental results by artificial neural networks.

    Science.gov (United States)

    Khataee, A R; Movafeghi, A; Vafaei, F; Lisar, S Y Salehi; Zarei, M

    2013-01-01

    The potential of an aquatic fern, Azolla filiculoides, in phytoremediation of a mono azo dye solution, C.I. Acid Blue 92 (AB92), was studied. The effects of operational parameters such as reaction time, initial dye concentration, fern fresh weight, pH, temperature and reusability of the fern on biodegradation efficiency were investigated. The intermediate compounds produced by biodegradation process were analyzed using GC-MS analysis. An artificial neural network (ANN) model was developed to predict the biodegradation efficiency. The findings indicated that ANN provides reasonable predictive performance (R2 = 0.961). The effects of AB92 solutions (10 and 20 mg L(-1)) on growth, chlorophylls and carotenoids content, activity of antioxidant enzymes such as superoxide dismutase, peroxidase and catalase and formation of malondialdehyde were analyzed. AB92 generally showed inhibitory effects on the growth. Moreover, photosynthetic pigments in the fronds significantly decreased in the treatments. An increase was detected for lipid peroxidation and antioxidant enzymes activity, suggesting that AB92 caused reactive oxygen species production in Azolla fronds, which were scavenged by induced activities of antioxidant enzymes.

  8. Light-limited growth and competition for light in well-mixed aquatic environments : An elementary model

    NARCIS (Netherlands)

    Huisman, Jef; Weissing, F.J.

    1994-01-01

    Light is never distributed homogeneously since it forms a gradient over biomass. As a consequence, the common theories on nutrient competition are not applicable to competition for light. In this paper, we investigate a model for light-limited growth and competition among phytoplankton species in a

  9. Development of a kinetic model for the removal of zinc using the aquatic macrophyte, Lemna gibba L.

    Science.gov (United States)

    Khellaf, N; Zerdaoui, M

    2012-01-01

    This work was conducted to develop a suitable kinetic model for the removal of zinc (Zn) using the duckweed Lemna gibba L. as a phytoremediation agent at laboratory scale. The 7-day treatments of 6.0-18.0 mg Zn/L were performed under controlled conditions: 12 h photoperiod, temperature of 21±1 °C, pH of 6.0±0.1 and a quarter Coïc and Lesaint solution as a culture medium. The results revealed a Zn removal efficiency of 60-70% and an accumulation capacity of plants ranging from 4.23 to 25.88 mg/g DM. Two simplified kinetic models namely pseudo-first-order and pseudo-second-order were used to study the mechanism that controls the biological process. The kinetic study proved that the removal rate of Zn by L. gibba was proportional to the Zn concentration present in water. Therefore, the pseudo-first-order model was considered to be more suitable to describe the disappearance of Zn from water in the presence of fronds of L. gibba L. These results may serve as a basis in mathematical modelling for large-scale application. PMID:22797221

  10. How TK-TD and population models for aquatic macrophytes could support the risk assessment for plant protection products

    NARCIS (Netherlands)

    Hommen, U.; Schmitt, W.; Heine, S.; Brock, T.C.M.; Duquesne, S.; Manson, P.; Meregali, G.; Ochoa-Acuna, H.; Vliet, van P.; Arts, G.H.P.

    2016-01-01

    This case study of the SETAC workshop MODELINK demonstrates the potential use of mechanistic effects models for macrophytes to extrapolate from effects of a plant protection product observed in laboratory tests to effects resulting from dynamic exposure on macrophyte populations in edge-of-field wat

  11. Bioavailability of PAHs in aluminum smelter affected sediments: evaluation through assessment of pore water concentrations and in vivo bioaccumulation.

    Science.gov (United States)

    Ruus, Anders; Bøyum, Olav; Grung, Merete; Næs, Kristoffer

    2010-12-15

    Bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) from coal tar pitch polluted sediments was predicted by (1) a generic approach based on organic carbon-water partitioning and Gibbs linear free energy relationship (between K(OW) and K(OC)), and (2) measurements of freely dissolved concentrations of PAHs in the sediment pore water, using passive samplers and solid phase extraction. Results from these predictions were compared with those from in vivo bioaccumulation experiments using Nereis diversicolor (Polychaeta), Hinia reticulata (Gastropoda), and Nuculoma tenuis (Bivalvia). Measured sediment/water partition coefficients were higher than predicted by the generic approach. Furthermore, predicted biota-to-sediment accumulation factors (BSAFs) derived from measured pore water concentrations were more in agreement with the bioaccumulation observed for two of the three species. Discrepancies associated with the third species (N. tenuis) were likely a result of particles remaining in the intestine (as shown by microscopic evaluation). These results indicate the importance of conducting site-specific evaluations of pore water concentrations and/or bioaccumulation studies by direct measurements to accurately provide a basis for risk assessment and remediation plans. The importance of knowledge regarding specific characteristics of model organisms is emphasized.

  12. Inter- and intraspecific variation in mercury bioaccumulation by snakes inhabiting a contaminated river floodplain.

    Science.gov (United States)

    Drewett, David V V; Willson, John D; Cristol, Daniel A; Chin, Stephanie Y; Hopkins, William A

    2013-04-01

    Although mercury (Hg) is a well-studied contaminant, knowledge about Hg accumulation in snakes is limited. The authors evaluated Hg bioaccumulation within and among four snake species (northern watersnakes, Nerodia sipedon; queen snakes, Regina septemvittata; common garter snakes, Thamnophis sirtalis; and rat snakes, Elaphe obsoleta [Pantherophis alleghaniensis]) from a contaminated site on the South River (Waynesboro, VA, USA) and two nearby reference sites. Total Hg (THg) concentrations in northern watersnake tail tissue at the contaminated site ranged from 2.25 to 13.84 mg/kg dry weight (mean: 4.85 ± 0.29), or 11 to 19 times higher than reference sites. Blood THg concentrations (0.03-7.04 mg/kg wet wt; mean: 2.24 ± 0.42) were strongly correlated with tail concentrations and were the highest yet reported in a snake species. Within watersnakes, nitrogen stable isotope values indicated ontogenetic trophic shifts that correlated with THg bioaccumulation, suggesting that diet plays a substantial role in Hg exposure. Female watersnakes had higher mean THg concentrations (5.67 ± 0.46 mg/kg) than males (4.93 ± 0.49 mg/kg), but no significant differences between sexes were observed after correcting for body size. Interspecific comparisons identified differences in THg concentrations among snake species, with more aquatic species (watersnakes and queen snakes) accumulating higher mean concentrations (5.60 ± 0.40 and 4.59 ± 0.38 mg/kg in tail tissue, respectively) than the more terrestrial species, garter snakes and rat snakes (1.28 ± 0.32 and 0.26 ± 0.09 mg/kg, respectively). The results of the present study warrant further investigation of potential adverse effects and will aid in prioritizing conservation efforts.

  13. Uranium bioaccumulation in a freshwater ecosystem: Impact of feeding ecology

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, Lisa D., E-mail: lisakraemer@trentu.ca [Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 7B8 (Canada); Evans, Douglas [Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 7B8 (Canada)

    2012-11-15

    Uranium bioaccumulation in a lake that had been historically affected by a U mine and (2) to use a combined approach of gut content examination and stable nitrogen and carbon isotope analysis to determine if U bioaccumulation in fish was linked to foodweb ecology. We collected three species of fish: smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus), in addition to several invertebrate species including freshwater bivalves (family: Sphaeriidae), dragonfly nymphs (order: Odonata), snails (class: Gastropoda) and zooplankton (family: Daphniidae). Results showed significant U bioaccumulation in the lake impacted by historical mining activities. Uranium accumulation was 2-3 orders of magnitude higher in invertebrates than in the fish species. Within fish, U was measured in operculum (bone), liver and muscle tissue and accumulation followed the order: operculum > liver > muscle. There was a negative relationship between stable nitrogen ratios ({sup 15}N/{sup 14}N) and U bioaccumulation, suggesting U biodilution in the foodweb. Uranium bioaccumulation in all three tissues (bone, liver, muscle) varied among fish species in a consistent manner and followed the order: bluegill > yellow perch > smallmouth bass. Collectively, gut content and stable isotope analysis suggests that invertebrate-consuming fish species (i.e. bluegill) have the highest U levels, while fish species that were mainly piscivores (i.e. smallmouth bass) have the lowest U levels. Our study highlights the importance of understanding the feeding ecology of fish when trying to predict U accumulation.

  14. Uranium bioaccumulation in a freshwater ecosystem: Impact of feeding ecology

    International Nuclear Information System (INIS)

    Uranium bioaccumulation in a lake that had been historically affected by a U mine and (2) to use a combined approach of gut content examination and stable nitrogen and carbon isotope analysis to determine if U bioaccumulation in fish was linked to foodweb ecology. We collected three species of fish: smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus), in addition to several invertebrate species including freshwater bivalves (family: Sphaeriidae), dragonfly nymphs (order: Odonata), snails (class: Gastropoda) and zooplankton (family: Daphniidae). Results showed significant U bioaccumulation in the lake impacted by historical mining activities. Uranium accumulation was 2–3 orders of magnitude higher in invertebrates than in the fish species. Within fish, U was measured in operculum (bone), liver and muscle tissue and accumulation followed the order: operculum > liver > muscle. There was a negative relationship between stable nitrogen ratios (15N/14N) and U bioaccumulation, suggesting U biodilution in the foodweb. Uranium bioaccumulation in all three tissues (bone, liver, muscle) varied among fish species in a consistent manner and followed the order: bluegill > yellow perch > smallmouth bass. Collectively, gut content and stable isotope analysis suggests that invertebrate-consuming fish species (i.e. bluegill) have the highest U levels, while fish species that were mainly piscivores (i.e. smallmouth bass) have the lowest U levels. Our study highlights the importance of understanding the feeding ecology of fish when trying to predict U accumulation.

  15. Scaling macroscopic aquatic locomotion

    Science.gov (United States)

    Gazzola, Mattia; Argentina, Mederic; Mahadevan, Lakshminarayanan

    2014-11-01

    Inertial aquatic swimmers that use undulatory gaits range in length L from a few millimeters to 30 meters, across a wide array of biological taxa. Using elementary hydrodynamic arguments, we uncover a unifying mechanistic principle characterizing their locomotion by deriving a scaling relation that links swimming speed U to body kinematics (tail beat amplitude A and frequency ω) and fluid properties (kinematic viscosity ν). This principle can be simply couched as the power law Re ~ Swα , where Re = UL / ν >> 1 and Sw = ωAL / ν , with α = 4 / 3 for laminar flows, and α = 1 for turbulent flows. Existing data from over 1000 measurements on fish, amphibians, larvae, reptiles, mammals and birds, as well as direct numerical simulations are consistent with our scaling. We interpret our results as the consequence of the convergence of aquatic gaits to the performance limits imposed by hydrodynamics.

  16. Bioaccumulation of dissociating substances; Bioakkumulation dissoziierender Stoffe

    Energy Technology Data Exchange (ETDEWEB)

    Butte, W.; Plegge, V.; Schettgen, C.; Willenborg, R.; Zauke, G.P. [Oldenburg Univ. (Germany). Fachbereich Chemie; Kuhlmann, H. [Oldenburg Univ. (Germany). Fachbereich Chemie]|[Bundesforschungsanstalt fuer Fischerei, Ahrensburg (Germany). Inst. fuer Fischereioekologie

    2000-02-01

    Bioconcentration factors (BCF) are important parameters to assess the environmental fate of chemicals. In this report we describe the determination of BCF for Triclosan, a trichlorophenoxy phenol, for some dissociating herbicides like Dichlorprop, MCPA, Mecoprop, Triclopyr and Picloram as well as for selected pyrethroids like Cyfluthrin, Cypermethrin, Deltamethrin and Permethrin. It was shown that BCF and rate constants for the uptake of Triclosan are decreasing with an increasing pH of the test water. The BCF for the herbicides evaluated are all below 10, confirming data already reported for herbicides of similar structure. Thus, for these compounds there is no tendency to bioaccumulate. Furthermore, there was no correlation between BCF and n-octanol/water partition coefficients or dissociation constants. BCF of pyrethroids were between 860 and 2200. For the analysis of pyrenthroid metabolites a gas chromatographic method using daughter-ion mass spectrometry for detection was established. The detection limit of this method was 1 {mu}g/kg, but metabolites could not be detected in fish during the bioaccumulation experiments. The high toxicity of pyrethroids for fish was approved; LC50-values were between 1 and 5 {mu}g/l. To evaluate physiological effects in fish, produced by pyrethroids, EROD activities in preparations of trout liver were measured. No increase in activity could be detected, but there was a tendency to lower values. We think this to result from the high toxicity of pyrethroids that could have impaired this enzyme system. (orig.) [German] Biokonzentrationsfaktoren (BCF) sind wichtige Parameter, mit Hilfe derer das Umweltverhalten von Chemikalien abgeschaetzt werden kann. Im Rahmen dieses Forschungsvorhabens wurden BCF-Werte fuer Triclosan, ein Trichlorphenoxyphenol, fuer einige dissoziierende Herbizide: Dichlorprop, MCPA, Mecoprop, Triclopyr und Picloram sowie fuer ausgewaehlte Pyrethroide: Cyfluthrin, Cypermethrin, Deltamethrin und Permethrin

  17. Modeling of hydroecological feedbacks predicts distinct classes of landscape pattern, process, and restoration potential in shallow aquatic ecosystems

    Science.gov (United States)

    Larsen, Laurel G.; Harvey, Judson W.

    2011-01-01

    It is widely recognized that interactions between vegetation and flow cause the emergence of channel patterns that are distinct from the standard Schumm classification of river channels. Although landscape pattern is known to be linked to ecosystem services such as habitat provision, pollutant removal, and sustaining biodiversity, the mechanisms responsible for the development and stability of different landscape patterns in shallow, vegetated flows have remained poorly understood. Fortunately, recent advances have made possible large-scale models of flow through vegetated environments that can be run over a range of environmental variables and over timescales of millennia. We describe a new, quasi-3D cellular automata model that couples simulations of shallow-water flow, bed shear stresses, sediment transport, and vegetation dynamics in an efficient manner. That efficiency allowed us to apply the model widely in order to determine how different hydroecological feedbacks control landscape pattern and process in various types of wetlands and floodplains. Distinct classes of landscape pattern were uniquely associated with specific types of allogenic and autogenic drivers in wetland flows. Regular, anisotropically patterned wetlands were dominated by allogenic processes (i.e., processes driven by periodic high water levels and flow velocities that redistribute sediment), relative to autogenic processes (e.g., vegetation production, peat accretion, and gravitational erosion). These anistropically patterned wetlands are therefore particularly prone to hydrologic disturbance. Other classes of wetlands that emerged from simulated interactions included maze-patterned, amorphous, and topographically noisy marshes, open marsh with islands, banded string-pool sequences perpendicular to flow, parallel deep and narrow channels flanked by marsh, and ridge-and-slough patterned marsh oriented parallel to flow. Because vegetation both affects and responds to the balance between the

  18. Aquatic macroinvertebrates of the Jablanica river, Serbia

    Directory of Open Access Journals (Sweden)

    Stefanović Katarina S.

    2009-01-01

    Full Text Available Research on the community of aquatic macroinvertebrates was carried out during 2005 and 2006 at four sampling sites along the Jablanica River, a right-hand tributary of the Kolubara River. Fifty-seven taxa were recorded in the course of the investigation. The most diverse group was Ephemeroptera, followed by Trichoptera and Plecoptera. Members of the Rhitrogena semicolorata group were the most abundant. Our results could be the basis for evaluation of the influence of damming of the Jablanica River on the status of its water and can serve as a model for studying the influ­ence of hydromorphological degradation of aquatic ecosystems.

  19. Modeling of hydroecological feedbacks predicts distinct classes of landscape pattern, process, and restoration potential in shallow aquatic ecosystems

    Science.gov (United States)

    Larsen, Laurel G.; Harvey, Judson W.

    2011-03-01

    It is widely recognized that interactions between vegetation and flow cause the emergence of channel patterns that are distinct from the standard Schumm classification of river channels. Although landscape pattern is known to be linked to ecosystem services such as habitat provision, pollutant removal, and sustaining biodiversity, the mechanisms responsible for the development and stability of different landscape patterns in shallow, vegetated flows have remained poorly understood. Fortunately, recent advances have made possible large-scale models of flow through vegetated environments that can be run over a range of environmental variables and over timescales of millennia. We describe a new, quasi-3D cellular automata model that couples simulations of shallow-water flow, bed shear stresses, sediment transport, and vegetation dynamics in an efficient manner. That efficiency allowed us to apply the model widely in order to determine how different hydroecological feedbacks control landscape pattern and process in various types of wetlands and floodplains. Distinct classes of landscape pattern were uniquely associated with specific types of allogenic and autogenic drivers in wetland flows. Regular, anisotropically patterned wetlands were dominated by allogenic processes (i.e., processes driven by periodic high water levels and flow velocities that redistribute sediment), relative to autogenic processes (e.g., vegetation production, peat accretion, and gravitational erosion). These anistropically patterned wetlands are therefore particularly prone to hydrologic disturbance. Other classes of wetlands that emerged from simulated interactions included maze-patterned, amorphous, and topographically noisy marshes, open marsh with islands, banded string-pool sequences perpendicular to flow, parallel deep and narrow channels flanked by marsh, and ridge-and-slough patterned marsh oriented parallel to flow. Because vegetation both affects and responds to the balance between the

  20. Performance evaluation on aquatic product cold-chain logistics

    Directory of Open Access Journals (Sweden)

    Wenbing Wu

    2015-11-01

    Full Text Available Purpose: The requirements for high quality and diversification aquatic products are increasing with the improvement of Chinese living standard. However, the distribution between place of production and place of consumption are uneven, which results in large cold-chain logistics demand for aquatic products. At present, the low-level development of cold chain logistics has a bad impact on the circulation of aquatic products in China. So it is very urgent to develop cold-chain logistics in China. Design/methodology/approach: In order to do this, we apply performance evaluation, a well-known management tool, to study Chinese aquatic product cold-chain logistics. In this paper we first propose SISP(Subjects, Indexes, Standards, and Phases of performance evaluation model and ACSSN model(Aquatic product, Customer, Supply Chain, Society, and Node enterprises of supply chain for aquatic products cold-chain logistics performance evaluation. Then an ANP-Fuzzy method is proposed to evaluate the operational performance of Shandong Oriental Ocean Sci-Tech Co., Ltd. Furthermore, a system dynamic model is built to simulate the impact of temperature on the profits in aquatic products cold-chain sales section. Findings: We find out within a reasonable temperature range, lower temperature brings higher profit level. Also, performance improvement methods are proposed and the simulation of performance evaluation system is developed. Practical implications: Our findings can help to improve the level of aquatic product cold-chain logistics in China. Originality/value: The paper proposes the SISP (Subjects, Indexes, Standards, and Phases of performance evaluation model and ACSSN model (Aquatic product, Customer, Supply Chain, Society, and Node enterprises of supply chain for aquatic products cold-chain logistics performance evaluation.

  1. Bioaccumulation of total mercury in the earthworm Eisenia andrei

    OpenAIRE

    Le Roux, Shirley; Baker, Priscilla; Crouch, Andrew

    2016-01-01

    Earthworms are a major part of the total biomass of soil fauna and play a vital role in soil maintenance. They process large amounts of plant and soil material and can accumulate many pollutants that may be present in the soil. Earthworms have been explored as bioaccumulators for many heavy metal species such as Pb, Cu and Zn but limited information is available for mercury uptake and bioaccumulation in earthworms and very few report on the factors that influence the kinetics of Hg uptake by ...

  2. The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

    DEFF Research Database (Denmark)

    Douglas, Thomas A.; Loseto, Lisa L.; MacDonald, Robie W.;

    2012-01-01

    into the Arctic by oceanic, atmospheric and terrestrial pathways. Our focus is on the movement, transformation and bioaccumulation of Hg in aquatic (marine and fresh water) and terrestrial ecosystems. The processes most relevant to biological Hg uptake and the potential risk associated with Hg exposure...... the fate of Hg in most ecosystems, and the role of trophic processes in controlling Hg in higher order animals are also included. Case studies on Eastern Beaufort Sea beluga (Delphinapterus leucas) and landlocked Arctic char (Salvelinus alpinus) are presented as examples of the relationship between...

  3. A rational approach to selecting and ranking some pharmaceuticals of concern for the aquatic environment and their relative importance compared with other chemicals.

    Science.gov (United States)

    Donnachie, Rachel L; Johnson, Andrew C; Sumpter, John P

    2016-04-01

    Aquatic organisms can be exposed to thousands of chemicals discharged by the human population. Many of these chemicals are considered disruptive to aquatic wildlife, and the literature on the impacts of these chemicals grows daily. However, because time and resources are not infinite, research must focus on the chemicals that represent the greatest threat. One group of chemicals of increasing concern is pharmaceuticals, for which the primary challenge is to identify which represent the greatest threat. In the present study, a list of 12 pharmaceuticals was compiled based on scoring the prevalence of different compounds from previous prioritization reviews. These included rankings based on prescription data, environmental concentrations, predicted environmental concentration/predicted no-effect concentration (PEC/PNEC) ratios, persistency/bioaccumulation/(eco)toxicity (PBT), and fish plasma model approaches. The most frequently cited were diclofenac, paracetamol, ibuprofen, carbamazepine, naproxen, atenolol, ethinyl estradiol, aspirin, fluoxetine, propranolol, metoprolol, and sulfamethoxazole. For each pharmaceutical, literature on effect concentrations was compiled and compared with river concentrations in the United Kingdom. The pharmaceuticals were ranked by degree of difference between the median effect and median river concentrations. Ethinyl estradiol was ranked as the highest concern, followed by fluoxetine, propranolol, and paracetamol. The relative risk of these pharmaceuticals was compared with those of metals and some persistent organic pollutants. Pharmaceuticals appear to be less of a threat to aquatic organisms than some metals (Cu, Al, Zn) and triclosan, using this ranking approach. Environ Toxicol Chem 2016;35:1021-1027. © 2015 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC. PMID:26184376

  4. The use of enclosed plankton communities in aquatic ecotoxicology : fate effects of mercury, cadmium and selected aromatic organics in a marine model ecosystem

    NARCIS (Netherlands)

    Kuiper, J.

    1982-01-01

    Most investigations in ecotoxicology are carried out in the laboratory. Although laboratory experiments are indispensable and yield useful information, it is difficult if not impossible to extrapolate results of short-term laboratory tests currently in use to real field situations. The need in aquat

  5. Presence, fate and effects of the intense sweetener sucralose in the aquatic environment

    International Nuclear Information System (INIS)

    Sucralose (1,6-dichloro-1,6-dideoxy-b-D-fructo-furanosyl 4-chloro-4-deoxy-a-D-galactopyranoside), sold under the trade name Splenda®, has been detected in municipal effluents and surface waters in the United States and Europe. The environmental presence of sucralose has led to interest in the possibility of toxic effects in non-target species. This review presents an environmental risk assessment of sucralose based on available data concerning its presence, fate and effects in the environment. Sucralose, which is made by selective chlorination of sucrose, is a highly stable compound, which undergoes negligible metabolism in mammals, including humans, and displays a low biodegradation potential in the environment. This intense sweetener is highly soluble in water, displays a low bioaccumulation potential and a low sorption potential to soil and organic matter, and thus is predominantly present in the water column. The predicted environmental concentration (PEC) for sucralose, based on measured data in surface waters, was determined to be 10 μg/L. Aquatic toxicity studies using standardized, validated protocols used in regulatory decision making indicate that sucralose does not alter survival, growth and reproduction of aquatic organisms (such as plants, algae, crustaceans and fish) at concentrations > 9000 times higher than those detected in the environment. Some studies, using non-standardized protocols, have reported behavioral and other non-traditional responses in aquatic organisms, but the relevance of these findings for assessing adverse effects on individuals and populations will require further investigation. In terms of traditional risk assessment, the proposed predicted no effect concentration for aquatic organisms (PNEC) was determined to be 0.93 mg/L, based on the lowest no effect concentration (NOEC) from a validated chronic study with mysid shrimp and an application factor of 100. The resultant PEC/PNEC quotient was determined to be well below 1 (PEC

  6. Presence, fate and effects of the intense sweetener sucralose in the aquatic environment

    Energy Technology Data Exchange (ETDEWEB)

    Tollefsen, Knut Erik, E-mail: ket@niva.no [Norwegian Institute for Water Research (NIVA), Gaustadalleen 21, N-0349 Oslo (Norway); Nizzetto, Luca [Norwegian Institute for Water Research (NIVA), Gaustadalleen 21, N-0349 Oslo (Norway); Huggett, Duane B. [Department of Biological Sciences, University of North Texas, P.O. Box 310559, Denton, TX 76203 (United States)

    2012-11-01

    Sucralose (1,6-dichloro-1,6-dideoxy-b-D-fructo-furanosyl 4-chloro-4-deoxy-a-D-galactopyranoside), sold under the trade name Splenda Registered-Sign , has been detected in municipal effluents and surface waters in the United States and Europe. The environmental presence of sucralose has led to interest in the possibility of toxic effects in non-target species. This review presents an environmental risk assessment of sucralose based on available data concerning its presence, fate and effects in the environment. Sucralose, which is made by selective chlorination of sucrose, is a highly stable compound, which undergoes negligible metabolism in mammals, including humans, and displays a low biodegradation potential in the environment. This intense sweetener is highly soluble in water, displays a low bioaccumulation potential and a low sorption potential to soil and organic matter, and thus is predominantly present in the water column. The predicted environmental concentration (PEC) for sucralose, based on measured data in surface waters, was determined to be 10 {mu}g/L. Aquatic toxicity studies using standardized, validated protocols used in regulatory decision making indicate that sucralose does not alter survival, growth and reproduction of aquatic organisms (such as plants, algae, crustaceans and fish) at concentrations > 9000 times higher than those detected in the environment. Some studies, using non-standardized protocols, have reported behavioral and other non-traditional responses in aquatic organisms, but the relevance of these findings for assessing adverse effects on individuals and populations will require further investigation. In terms of traditional risk assessment, the proposed predicted no effect concentration for aquatic organisms (PNEC) was determined to be 0.93 mg/L, based on the lowest no effect concentration (NOEC) from a validated chronic study with mysid shrimp and an application factor of 100. The resultant PEC/PNEC quotient was determined to be

  7. Bioaccumulation factor for 32P measured in bluegill, Lepomis macrochirus, and catfish, Ictalurus punctatus

    International Nuclear Information System (INIS)

    The ratio of the bioaccumulation factors for 32P and phosphorus was determined for edible tissue in two species of freshwater fish by measuring the specific activity (32P activity per milligram phosphorus) in muscle relative to feed. The 32P tracer was added to the feed at a uniform level throughout the study. Feeding was at two levels: ad libitum and at a lower but constant intake per body weight. In the main experiment, bluegill were maintained in a large flow-through tank and sacrificed at approximately weekly intervals for 51 d of 32P accumulation and 28 d of depuration to compare the specific activity with values predicted with a calculational model. In experiments performed in smaller aquaria, the specific activity in bluegill and catfish muscle was compared at two feeding levels and two temperatures. In addition, unfed fish were exposed to 32P in water at a known specific activity to determine the extent of phosphorus uptake directly from water. The pattern of specific activity increase and decrease in fish muscle during the accumulation/depuration experiment was consistent with a one-compartment model, so that specific activity ratios at steady state could be predicted from measurements during relatively brief exposures. On this basis, the ratio of the bioaccumulation factors of 32P and phosphorus in fish feeding ad libitum was 0.081 for bluegill and 0.17 for catfish. Hence, at a mean phosphorus bioaccumulation factor of 70,000, the factors for 32P are 6000 and 12,000, respectively. The ratios were less at lower phosphorus intakes associated with lower feeding rates; moreover, the lesser value for bluegill occurred at a much lower phosphorus intake than by catfish

  8. Conceptual Framework for Aquatic Interfaces

    Science.gov (United States)

    Lewandowski, J.; Krause, S.

    2015-12-01

    Aquatic interfaces are generally characterized by steep gradients of physical, chemical and biological properties due to the contrast between the two adjacent environments. Innovative measurement techniques are required to study the spatially heterogeneous and temporally variable processes. Especially the different spatial and temporal scales are a large challenge. Due to the steep biogeochemical gradients and the intensive structural and compositional heterogeneity, enhanced biogeochemical processing rates are inherent to aquatic interfaces. Nevertheless, the effective turnover depends strongly on the residence time distribution along the flow paths and in sections with particular biogeochemical milieus and reaction kinetics. Thus, identification and characterization of the highly complex flow patterns in and across aquatic interfaces are crucial to understand biogeochemical processing along exchange flow paths and to quantify transport across aquatic interfaces. Hydrodynamic and biogeochemical processes are closely coupled at aquatic interfaces. However, interface processing rates are not only enhanced compared to the adjacent compartments that they connect; also completely different reactions might occur if certain thresholds are exceeded or the biogeochemical milieu differs significantly from the adjacent environments. Single events, temporal variability and spatial heterogeneity might increase overall processing rates of aquatic interfaces and thus, should not be neglected when studying aquatic interfaces. Aquatic interfaces are key zones relevant for the ecological state of the entire ecosystem and thus, understanding interface functioning and controls is paramount for ecosystem management. The overall aim of this contribution is a general conceptual framework for aquatic interfaces that is applicable to a wide range of systems, scales and processes.

  9. Optimizing fish sampling for fish–mercury bioaccumulation factors

    Science.gov (United States)

    Fish Bioaccumulation Factors (BAFs; ratios of mercury (Hg) in fish (Hgfish) and water (Hgwater)) are used to develop total maximum daily load and water quality criteria for Hg-impaired waters. Both applications require representative Hgfish estimates and, thus, are sensitive to s...

  10. Development and field validation of a multimedia exposure assessment model for waste load allocation in aquatic ecosystems: Application to 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran in the Fraser River Watershed

    Energy Technology Data Exchange (ETDEWEB)

    Gobas, F.A.P.; Pasternak, J.P.; Lien, K.; Duncan, R.K. [Simon Fraser Univ., Burnaby, British Columbia (Canada). School of Resource and Environmental Management

    1998-08-15

    Knowledge of the relationship between contaminant emissions and ambient concentrations is crucial in achieving environmental quality objectives. This paper reports the development and field validation of EcoFate, a time dependent multimedia mass balance simulation model of the environmental distribution food-chain accumulation of organic contaminants in aquatic ecosystems. The purpose of the model is to present a methodology for deriving maximum daily-loading estimates in accordance with environmental quality objectives for a variety of aquatic ecosystems impacted by emissions from one or several point or nonpoint sources. The application of the model to multiple, time-varying pulp and paper mill discharges of 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran in the Fraser-Thompson River system from 1988 to 1995 is demonstrated. The ability of the model to predict chemical concentrations in various environmental media and organisms resulting from chemical emissions is tested against field data collected over a 7 year period. The results include (1) a comparison of observed and predicted concentrations, (2) an assessment of uncertainty, and (3) a test of the model`s temporal response to changes in contaminant loadings. The application of the model for the derivation of maximum daily loadings for multiple point sources in watersheds is illustrated.

  11. Bioavailability of Polycyclic Aromatic Hydrocarbons in aquatic ecosystems : influence of natural and anthropic organic matter; Biodisponibilite des hydrocarbures aromatiques polycycliques dans les ecosystemes aquatiques: influence de la matiere organique naturelle et anthropique

    Energy Technology Data Exchange (ETDEWEB)

    Gourlay, C.

    2004-11-01

    Aquatic ecosystems receive micro-pollutants. They also contain organic matter (OM) of natural and anthropogenic origins. The contaminant bioavailability in aquatic media is determined by the interactions between contaminants and OM. This work deals with the influence of organic matter from anthropogenic media on the bioavailability of hydrophobic organic pollutants. Polycyclic Aromatic Hydrocarbons (PAHs) have been used as model contaminants, since they are widely spread in urban media. In anthropogenic media, some OM may be bio-degraded. Up to now, most researches focused on the interactions between contaminants and humic OM that are mostly non-degradable, using physico-chemical characterizations of OM. On the contrary, in this work, the biodegradability of OM was deliberately taken into account. Indeed, we assume that the contaminant affinity for OM evolves during OM biodegradation, so that pollutants may be released in a bio-available form and then may be bond again by biodegradation sub-products. In laboratory evaluation, PAH bioavailability was assessed through the measurements of the bioaccumulation in Daphnia magna. The influence of organic matter on the bioavailability of PAHs and the evolution of this influence along OM bacterial mineralization were proved, as well as the strong binding efficiency of degradation by-products. A model of observed phenomena was elaborated. These observations about urban and natural OM effect were compared to in situ PAH bioavailability measurements in the river Seine basin. In this case, the bioavailability was estimated using Semi-Permeable Membrane Device (SPMD) sampling technique. (author)

  12. Effects of aqueous effluents from in situ fossil fuel processing technologies on aquatic systems. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, H.L.; Anderson, A.D.

    1977-12-01

    This is the first annual report issued under a project to evaluate the effects of aqueous effluents from in-situ fossil fuel processing technologies on aquatic biota. Briefly, the goals of the project are to: evaluate the toxicity of process water effluents on aquatic biota; recommend maximum exposure concentrations for process water constituents; and assist DOE in using project data and recommendations to design control technologies and to assess environmental impacts. The project objectives for Year 1 were pursued through the following five tasks: a literature review on process water constituents; toxicity studies on the effect of process waters and six process water constituents on aquatic biota; degradation rate studies on four to six process water constituents; bioaccumulation studies on four to six process water constituents; and recommendations on maximum exposure concentrations for process water constituents based on data from the project and from the literature. Progress toward completion of these goals is presented.

  13. Bioaccumulation of P-32 in bluegill and catfish

    International Nuclear Information System (INIS)

    Bluegill and catfish were fed P-32 at a constant feeding rate per body weight to determine the bioaccummulation factor (BF/sub r/) for P-32 in muscle relative to water. The fish were maintained in flow-through tanks at two feeding levels. The bluegill accumulated P-32 for 51 days, followed by depuration for 28 days. The catfish study had to be teminated after 11 days. Fish were analyzed in triplicte for P-32 and phosphorus at intervals of 1 to 8 days. Additional aquaria experiments were performed to determine the effects of water temperature, feeding rate, and type of food (worms vs. pellets) on P-32 uptake, and to observe P-32 uptake from water by unfed fish (including fish with blocked esophagus). A simple calculational model was used to determine the phosphorus turnover constant from the specific activity in tissue relative to food. This ratio at steady state approaches the BF/sub r/BF ratio (where BF is the phosphorus bioaccumulation factor) if P-32 transfers rapidly from water to food. The bluegill showed a weight gain of 0.2 %/d, a phosphorous turnover constant in muscle of 0.43 %/d, and a BF/sub r//BF ratio of 0.081 at the higher feeding rate, and 0.05 %/d, 0.34 %/d, and 0.064 at the lower feeding rate. Hence, respective P-32 BF/sub r/ values are 6000 and 4000 at a phosphorus BF of 70,000. The BF/sub r/ values for catfish were approximately twice as high. The aquarium experiments suggest that the higher factors are due to a much higher phosphorus intake, higher water temperature, higher retention from pellets than from worms, and possible higher retention by catfish than bluegill under the same conditions. 36 references, 15 figures, 22 tables

  14. Uranium bioaccumulation in a freshwater ecosystem: impact of feeding ecology.

    Science.gov (United States)

    Kraemer, Lisa D; Evans, Douglas

    2012-11-15

    The objectives of our study were: (1) to determine if there was significant uranium (U) bioaccumulation in a lake that had been historically affected by a U mine and (2) to use a combined approach of gut content examination and stable nitrogen and carbon isotope analysis to determine if U bioaccumulation in fish was linked to foodweb ecology. We collected three species of fish: smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus), in addition to several invertebrate species including freshwater bivalves (family: Sphaeriidae), dragonfly nymphs (order: Odonata), snails (class: Gastropoda) and zooplankton (family: Daphniidae). Results showed significant U bioaccumulation in the lake impacted by historical mining activities. Uranium accumulation was 2-3 orders of magnitude higher in invertebrates than in the fish species. Within fish, U was measured in operculum (bone), liver and muscle tissue and accumulation followed the order: operculum>liver>muscle. There was a negative relationship between stable nitrogen ratios ((15)N/(14)N) and U bioaccumulation, suggesting U biodilution in the foodweb. Uranium bioaccumulation in all three tissues (bone, liver, muscle) varied among fish species in a consistent manner and followed the order: bluegill>yellow perch>smallmouth bass. Collectively, gut content and stable isotope analysis suggests that invertebrate-consuming fish species (i.e. bluegill) have the highest U levels, while fish species that were mainly piscivores (i.e. smallmouth bass) have the lowest U levels. Our study highlights the importance of understanding the feeding ecology of fish when trying to predict U accumulation. PMID:22963859

  15. Bioaccumulation and toxicity of selenium during a life-cycle exposure with desert pupfish (Cyprinodon macularius)

    Science.gov (United States)

    2012-01-01

    Populations of desert pupfish (Cyprinodon macularius; pupfish), a federally-listed endangered species, inhabit irrigation drains in the Imperial Valley agricultural area of southern California. These drains have varying degrees of selenium (Se) contamination of water, sediment, and aquatic biota. Published Se toxicity studies suggest that these levels of Se contamination may pose risk of chronic toxicity to Se-sensitive fish, but until recently there have been no studies of the chronic toxicity of Se to desert pupfish. A life-cycle Se exposure with pupfish was conducted to estimate dietary and tissue thresholds for toxic effects of Se on all life stages. The dietary exposure was based on live oligochaete worms (Lumbriculus variegatus) dosed with Se by a laboratory food chain based on selenized yeast. Oligochaetes readily accumulated Se from mixtures of selenized and control yeasts. The protocol for dosing oligochaetes for pupfish feeding studies included long-term (at least 28 days) feeding of a low-ration of yeast mixtures to large batches of oligochaetes. Oligochaetes were dosed at five Se levels in a 50-percent dilution series. Pupfish were simultaneously fed Se-dosed oligochaetes and exposed to a series of Se concentrations in water (consisting of 85 percent selenate and 15 percent selenite) to produce exposures that were consistent with Se concentrations and speciation in pupfish habitats. The nutritional characteristics of oligochaete diets were consistent across the range of oligochaete Se concentrations tested. The life-cycle exposure started with laboratory-cultured juvenile pupfish that were exposed to Se through sexual maturation and reproduction (150 days; F0 exposure). The Se exposure continued with eggs, larvae, and juveniles produced by Se-exposed parents (79 days; F1 exposure). Selenium exposure (water and diets), Se bioaccumulation (whole-body and eggs), and toxicity endpoints (juvenile and adult survival and growth; egg production and hatching

  16. Enantiomer-specific toxicity and bioaccumulation of alpha-cypermethrin to earthworm Eisenia fetida.

    Science.gov (United States)

    Diao, Jinling; Xu, Peng; Liu, Donghui; Lu, Yule; Zhou, Zhiqiang

    2011-09-15

    Alpha-cypermethrin, a synthetic pyrethroid, is highly effective against a wide range of chewing and sucking insects in crops, and it is a racemic mixture of two enantiomers ((+)-1R-cis-αS+(-)-1S-cis-αR). Studies about the toxicity of alpha-cypermethrin to non-target organisms are mainly focused on aquatic organisms, whereas information regarding terrestrial organisms is relatively much less. Very little report about its enantioselective toxicity is known, so the present study tested the enantiomer-specific acute toxicity to earthworm Eisenia fetida. Experiment about bioaccumulation of two enantiomers in soil was conducted, peak-shaped accumulation curves were observed for both enantiomers, and the calculated biota to soil accumulations factor (BSAF) have significant difference between the two enantiomers. It was obvious that earthworm can uptake alpha-cypermethrin enantioselectively, preferentially accumulating (-)-(1S-cis-αR)-enantiomer. Great difference in toxicity to earthworm between two enantiomers was found, and the calculated LC(50) values for (+)-(1R-cis-αS)-, (-)-(1S-cis-αR)-, and rac-alpha-cypermethrin were 49.53, 1663.87 and 165.61 ng/cm(2), respectively. The acute toxicity of alpha-cypermethrin enantiomers was enantioselective.

  17. Bioaccumulation of selenium (Se) in the Cienega de Santa Clara wetland, Sonora, Mexico.

    Science.gov (United States)

    García-Hernández, J; Glenn, E P; Artiola, J; Baumgartner, D J

    2000-07-01

    The Cienega de Santa Clara, on the east side of the Colorado River delta, is a brackish wetland supported by agricultural drainage water from the United States that provides habitat for endangered fish and bird species. Bioaccumulation of selenium has created toxicity problems for wildlife in similar wetlands in the United States. This is the first selenium survey in the Cienega de Santa Clara. Ten sites were selected to collect water (dissolved), sediments (total), plants, invertebrates, and fish. Samples were collected from October 1996 to March 1997. Selenium was detected in all samples. Concentrations in water ranged from 5 to 19 microg/L and increased along a salinity gradient. Although water levels of selenium exceeded EPA criterion for protection of wildlife, levels in sediments (0.8-1.8 mg/kg), aquatic plants (0.03-0.17 mg/kg), and fish (2.5-5.1 mg/kg whole body, dry wt) did not exceed USFWS recommended levels. It is concluded from this study that the levels of selenium in water did not affect the overall health of the fish sampled. Therefore, it is important to maintain or improve the water quality entering this wetland to continue to have normal levels of Se in the food chain components.

  18. Heavy metals toxicity and bioaccumulation patterns in the body organs of four fresh water fish species

    Directory of Open Access Journals (Sweden)

    Safina Kousar and Muhammad Javed

    2014-04-01

    Full Text Available Various environmental pollutants, including metals can cause toxicological effects on aquatic animals especially fish species. Laboratory experiments were conducted to determine acute toxicity and bioaccumulation patterns of arsenic (As, nickel (Ni and zinc (Zn in 150-day old fish species (Labeo rohita, Cirrhina mrigala, Catla catla and Ctenopharyngodon idella, separately, in glass aquaria under constant water temperature (30oC, total hardness (300 mg L-1 and pH (7.5. Catla catla showed significantly (PNi>As. Among exposed fish species, Cirrhina mrigala exhibited significantly higher ability to amass Ni (146.8±149.1 μg g-1 and Zn (243.0±190.5 μg g-1, followed by Ctenopharyngodon idella, Labeo rohita and Catla catla at 96-h LC50. Liver showed higher tendency to accumulate Ni, followed by gills and kidney with significant differences while kidney showed higher tendency to accumulate As, followed by liver. Fins and scales exhibited significantly (P<0.05 least tendency to accumulate all the three metals. Accumulation of metals in different fish species is the function of their membrane permeability, which is highly species specific. Due to this reason different fish species showed different amount of metal accumulated in their bodies. This study also reveals that the metals, being conservative in nature have higher ability of biomagnifications.

  19. Mercury in Pacific bluefin tuna (Thunnus orientalis):bioaccumulation and trans-Pacific Ocean migration

    Science.gov (United States)

    Colman, John A.; Nogueira, Jacob I.; Pancorbo, Oscar C.; Batdorf, Carol A.; Block, Barbara A.

    2015-01-01

    Pacific bluefin tuna (Thunnus orientalis) have the largest home range of any tuna species and are well known for the capacity to make transoceanic migrations. We report the measurement of mercury (Hg) concentrations in wild Pacific bluefin tuna (PBFT), the first reported with known size-of-fish and capture location. The results indicate juvenile PBFT that are recently arrived in the California Current from the western Pacific Ocean have significantly higher Hg concentrations in white muscle (0.51 ug/g wet mass, wm) than PBFT of longer California Current residency (0.41 ug/g wm). These new arrivals are also higher in Hg concentration than PBFT in farm pens (0.43 ug/g wm) that were captured on arrival in the California Current and raised in pens on locally derived feed. Analysis by direct Hg analyzer and attention to Hg by tissue type and location on the fish allowed precise comparisons of mercury among wild and captive fish populations. Analysis of migration and nearshore residency, determined through extensive archival tagging, bioaccumulation models, trophic investigations, and potential coastal sources of methylmercury, indicates Hg bioaccumulation is likely greater for PBFT juvenile habitats in the western Pacific Ocean (East China Sea, Yellow Sea) than in the eastern Pacific Ocean (California Current). Differential bioaccumulation may be a trophic effect or reflect methylmercury availability, with potential sources for coastal China (large hypoxic continental shelf receiving discharge of three large rivers, and island-arc volcanism) different from those for coastal Baja California (small continental shelf, no large rivers, spreading-center volcanism).

  20. Interactions between zooplankton and crude oil: toxic effects and bioaccumulation of polycyclic aromatic hydrocarbons.

    Directory of Open Access Journals (Sweden)

    Rodrigo Almeda

    Full Text Available We conducted ship-, shore- and laboratory-based crude oil exposure experiments to investigate (1 the effects of crude oil (Louisiana light sweet oil on survival and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs in mesozooplankton communities, (2 the lethal effects of dispersant (Corexit 9500A and dispersant-treated oil on mesozooplankton, (3 the influence of UVB radiation/sunlight exposure on the toxicity of dispersed crude oil to mesozooplankton, and (4 the role of marine protozoans on the sublethal effects of crude oil and in the bioaccumulation of PAHs in the copepod Acartia tonsa. Mortality of mesozooplankton increased with increasing oil concentration following a sigmoid model with a median lethal concentration of 32.4 µl L(-1 in 16 h. At the ratio of dispersant to oil commonly used in the treatment of oil spills (i.e. 1∶20, dispersant (0.25 µl L(-1 and dispersant-treated oil were 2.3 and 3.4 times more toxic, respectively, than crude oil alone (5 µl L(-1 to mesozooplankton. UVB radiation increased the lethal effects of dispersed crude oil in mesozooplankton communities by 35%. We observed selective bioaccumulation of five PAHs, fluoranthene, phenanthrene, pyrene, chrysene and benzo[b]fluoranthene in both mesozooplankton communities and in the copepod A. tonsa. The presence of the protozoan Oxyrrhis marina reduced sublethal effects of oil on A. tonsa and was related to lower accumulations of PAHs in tissues and fecal pellets, suggesting that protozoa may be important in mitigating the harmful effects of crude oil exposure in copepods and the transfer of PAHs to higher trophic levels. Overall, our results indicate that the negative impact of oil spills on mesozooplankton may be increased by the use of chemical dispersant and UV radiation, but attenuated by crude oil-microbial food webs interactions, and that both mesozooplankton and protozoans may play an important role in fate of PAHs in marine environments.

  1. Accumulation and fluxes of mercury in terrestrial and aquatic food chains with special reference to Finland

    Directory of Open Access Journals (Sweden)

    Martin Lodenius

    2013-03-01

    Full Text Available Mercury is known for its biomagnification especially in aquatic food chains and for its toxic effects on different organisms including man. In Finland mercury has formerly been used in industry and agriculture and in addition many anthropogenic activities may increase the mercury levels in ecosystems. Phenyl mercury was widely used as slimicide in the pulp and paper industry in the 1950s and 1960s. In the chlor-alkali industry metallic mercury was used as catalyst at three plants. The most toxic form of mercury, methyl mercury, may be formed in soils, water, sediments and organisms. Many factors, including microbial activity, temperature, oxygen status etc., affect the methylation rate. In the lake ecosystem bioaccumulation of methyl mercury is very strong. In early 1980s there was a restriction of fishing concerning approximately 4000 km2 of lakes and sea areas because of mercury pollution. In aquatic systems we still find elevated concentrations near former emission sources. Long-range atmospheric transport and mechanical operations like ditching and water regulation may cause increased levels of mercury in the aquatic ecosystems. In the Finnish agriculture organic mercury compounds were used for seed dressing until 1992. Although the amounts used were substantial the concentrations in agricultural soils have remained rather low. In terrestrial food chains bioaccumulation is normally weak with low or moderate concentration at all ecosystem levels. Due to a weak uptake through roots terrestrial, vascular plants normally contain only small amounts of mercury. There is a bidirectional exchange of mercury between vegetation and atmosphere. Contrary to vascular plants, there is a very wide range of concentrations in fungi. Mercury may pose a threat to human health especially when accumulated in aquatic food chains.

  2. Tool use by aquatic animals.

    Science.gov (United States)

    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. PMID:24101631

  3. The use of enclosed plankton communities in aquatic ecotoxicology : fate effects of mercury, cadmium and selected aromatic organics in a marine model ecosystem

    OpenAIRE

    Kuiper, J.

    1982-01-01

    Most investigations in ecotoxicology are carried out in the laboratory. Although laboratory experiments are indispensable and yield useful information, it is difficult if not impossible to extrapolate results of short-term laboratory tests currently in use to real field situations. The need in aquatic ecotoxicology for experiments with complex systems, more closely approximating natural conditions, led to the use of large, flexible plastic bags, isolating part of the ecosystem, and suspended ...

  4. Is Zeolite a Detoxificant: Modelling of Ferrous Chloride/Zeolite Application of Aquatic Organisms on Rainbow Trout (Oncorhynchus mykiss to Determine Its Effects on Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Arzu UÇAR

    2016-08-01

    Full Text Available Populations of native fish and aquatic ecosystems have been negatively affected by the contamination of ground and surface waters as a result of various activities. Due to the ferrous chloride (FeCl2, which is used as the reducing agent for the organic synthesis reactions in the contamination of water column and sediment, iron salts may be very toxic for some aquatic organism. In order to minimize these effects, natural products such as zeolite have been widely used recently. For this reason, rainbow trout (Oncorhynchus mykiss were exposed to FeCl2 and/or zeolite for 28 days and their oxidative stress responses were investigated. At the end of the treatment period, oxidative stress responses were determined with antioxidant enzyme activities in the samples taken from liver and kidneys. CAT, SOD, GPx and MDA values for kidney and liver tissues were found statistically important between control and treatment groups (p<0.05. In this study, zeolite application provided lower values in terms of enzyme activities, and the protective effect of zeolite for aquatic organism was supported by biochemical parameters. 

  5. Exposures from aquatic pathways

    International Nuclear Information System (INIS)

    Methods for estimation aquatic pathways contribution to the total population exposure are discussed. Aquatic pathways are the major factor for radionuclides spreading from the Chernobyl Exclusion zone. An annual outflow of 90Sr and 137Cs comprised 10-20 TBq and 2-4 TBq respectively and the population exposed by this effluence constitutes almost 30 million people. The dynamic of doses from 90Sr and 'Cs, which Dnieper water have to delivered, is calculated. The special software has been developed to simulate the process of dose formation in the of diverse Dnieper regions. Regional peculiarities of municipal tap, fishing and irrigation are considered. Seventy-year prediction of dose structure and function of dose forming is performed. The exposure is estimated for 12 regions of the Dnieper basin and the Crimea. The maximal individual annual committed effective doses due to the use of water by ordinary members of the population in Kiev region from 90Sr and 137Cs in 1986 are 1.7*10-5 Sv and 2.7*10-5 Sv respectively. A commercial fisherman on Kiev reservoir in 1986 received 4.7*10-4 Sv and 5*10-3 Sv from 90Sr and 137Cs, respectively. The contributions to the collective cumulative (over 70 years) committed effective dose (CCCED70) of irrigation, municipal tap water and fish consumption for members of the population respectively are 18%, 43%, 39% in Kiev region, 8%, 25%, 67% in Poltava region, and 50%, 50%, 0% (consumption of Dnieper fish is absent) in the Crimea. The predicted contribution of the Strontium-90 to CCCED70 resulting from the use of water is 80%. The CCCED70 to the population of the Dnieper regions (32.5 million people) is 3000 person-Sv due to the use the Dnieper water

  6. Uranium in Aquatic Sediments; Where are the Guidelines?

    International Nuclear Information System (INIS)

    Sediment data has been collected on and around the Ranger uranium mine for over 20 years. This included studies such as annual routine monitoring of metal concentrations, adsorption-desorption conditions, phase associations, transport mechanism, release potential, bioaccumulation and bioconcentration etc. Building on this, performance-based monitoring of the sediments from on-site water bodies was undertaken to ascertain the spatial and temporal distribution of contaminants as a basis to determine ecological risks associated with the sediments which in turn underpins closure planning. Highlights of these studies are interpreted using an ecological risk assessment approach. Ideally interpretation of aquatic sediment contamination in Australia is guided by the national guidelines for water quality and a weighted multiple lines of evidence approach whereby the chemistry of sediments is compared with reference and guideline values and predictions of bio-availability, and biological effects data allows cause and effect relationships to be derived. However, where uranium in aquatic sediments is concerned there is a lack of national (Australian) and international guidelines that are applicable to tropical sediments and the biological effects data available are limited or confounded by other variables. In the absence of clear uranium guidelines for sediments an internationally reported “Predicted No Effect Concentration” (PNEC) for uranium in temperate sediments was used as a “pseudo-guideline” value to identify sites with concentrations that might present an environmental risk and that should be further investigated. The applicability of the PNEC to the tropical Ranger site was understandably questioned by stakeholders and peers. The issues raised highlighted the need for international guidelines for uranium in aquatic sediments for tropical and temperate climates and an internationally accepted approach for deriving same. (author)

  7. The effect of organic and inorganic aqueous uranium speciation on U(VI) bioavailability to an aquatic invertebrate

    Science.gov (United States)

    Fuller, C.; Croteau, M. N.; Campbell, K. M.; Cain, D.; Aiken, G.

    2015-12-01

    Growing world-wide demand for uranium (U) as an energy source has raised concerns of the human and ecological risks of U extraction and processing in the United States. Because of limited information on the relationship between U speciation and bioavailability, particularly in aquatic animals, we are characterizing U uptake by a model freshwater invertebrate (the snail Lymnaea stagnalis). This species grazes on biofilms and is thus key in the trophic transfer of contaminants through aquatic food webs. We determined the bioavailability of dissolved U(VI) over a range of water hardness, pH (6 to 8), and the presence of dissolved natural organic matter (NOM) as a competing ligand, to test the effect of aqueous speciation on uptake. Bioavailability was assessed using U uptake rate constants (kuw) derived from a kinetic bioaccumulation model. Dissolved U (1 to 1000 nM) was bioavailable over the range of geochemical conditions tested with kuw (L/g/d) decreasing with increasing dissolved Ca and with increasing pH. For example, kuw decreased from 1.6 to 0.3 as dissolved Ca was increased from 0.04 to 1.5 mM, suggesting competition between bioavailable U(VI) species and strong ternary calcium uranyl carbonato complexes. At pH 7.5 in synthetic moderately hard freshwater, kuw decreased from 0.22 in the absence of NOM to 0.07 in the presence of a hydrophobic acid NOM isolate of high aromaticity (SUVA = 5) consistent with strong aqueous complexation of U(VI) by the NOM. The co-variance of U uptake and aqueous U species distribution is being analyzed to determine which U species are bioavailable. U speciation in systems with NOM is calculated using conditional U-NOM binding constants derived by equilibrium dialysis ligand exchange methodology. The bioavailability of dietborne U is being tested since dietary metal uptake prevails for many aquatic species. These experiments include addition of ferrihydrite with U sorbed, both in the presence and absence of NOM, and mixed with diet.

  8. Subcellular localisation of radionuclides by transmission electronic microscopy in aquatic and terrestrial organisms

    International Nuclear Information System (INIS)

    The global framework of this study is to go further in the understanding of the involved mechanisms of uranium and selenium internalisation at the subcellular level and of their toxicity towards several aquatic and terrestrial organisms. In this context, the applications and performances of a Scanning Transmission Electron Microscope (TEM/STEM) equipped with CCD camera and Energy-Dispersive- X-Ray (EDAX) analysis are reported. The principal merit of this equipment is the clear expression of element distribution with nanometer resolution. The sample for TEM analysis were prepared in ultrathin sections of 70-140 nm (thickness) and those for EDAX in sections of 200-500 nm. This method offers the possibility of a direct correlation between histological image and distribution map of trace elements. For each sample, following TEM analysis, EDAX spectra or EDAX mapping were also recorded to confirm the identity of the electron dense material in the scanned sections. Demonstration of the usefulness of this method to understand the bioaccumulation mechanisms and to study the effect of the pollutant uptake at the subcellular level was performed for target organs of a metal (U) and a metalloid (Se) in various biological models: a higher rooted plant (Phaseolus vulgaris)) and a freshwater invertebrate (Orconectes Limosus) and a unicellular green alga (Chlamydomonas reinhardtii)). TEM-EDAX analysis revealed the presence of U-deposits in gills and digestive gland in crayfish, and in vacuoles or in the cytoplasm of different rooted cells bean. In the alga, the accumulation of Se was found in electron-dense granules within cytoplasm associated with ultrastructural changes and starch accumulation. (author)

  9. Aquatic fungi: targeting the forgotten in microbial ecology.

    Science.gov (United States)

    Grossart, Hans-Peter; Rojas-Jimenez, Keilor

    2016-06-01

    Fungi constitute important and conspicuous components of aquatic microbial communities, but their diversity and functional roles remain poorly characterized. New methods and conceptual frameworks are required to accurately describe their ecological roles, involvement in global cycling processes, and utility for human activities, considering both cultivation-independent techniques as well as experiments in laboratory and in natural ecosystems. Here we highlight recent developments and extant knowledge gaps in aquatic mycology, and provide a conceptual model to expose the importance of fungi in aquatic food webs and related biogeochemical processes.

  10. Bioaccumulation of 226Ra by plants growing in fresh water ecosystem around the uranium industry at Jaduguda, India

    International Nuclear Information System (INIS)

    A field study has been conducted to evaluate the 226Ra bioaccumulation among aquatic plants growing in the stream/river adjoining the uranium mining and ore-processing complex at Jaduguda, India. Two types of plant group have been investigated namely free floating algal species submerged into water and plants rooted in stream and riverbed. The highest 226Ra activity concentration (9850 Bq kg-1) was found in filamentous algae growing in the residual water of tailings pond. The concentration ratios of 226Ra in filamentous algae (activity concentration of 226Ra in plant Bq kg-1 fresh weight/activity concentration of 226Ra in water Bq l-1) widely varied i.e. from 1.1 x 103 to 8.6 x 104. Other aquatic plants were also showing wide variability in the 226Ra activity concentration. The ln-transformed filamentous algae 226Ra activity concentration was significantly correlated with that of ln-transformed water concentration (r = 0.89, p 226Ra in stream/riverbed rooted plants and the substrate. For this group, correlation between 226Ra activity concentration and Mn, Fe, Cu concentration in plants were statistically significant.

  11. Bioaccumulation, subcellular, and molecular localization and damage to physiology and ultrastructure in Nymphoides peltata (Gmel.) O. Kuntze exposed to yttrium.

    Science.gov (United States)

    Fu, Yongyang; Li, Feifei; Xu, Ting; Cai, Sanjuan; Chu, Weiyue; Qiu, Han; Sha, Sha; Cheng, Guangyu; Xu, Qinsong

    2014-02-01

    Bioaccumulation, subcellular distribution, and acute toxicity of yttrium (Y) were evaluated in Nymphoides peltata. The effects of Y concentrations of 1-5 mg L(-1) applied for 4 days were assessed by measuring changes in photosynthetic pigments, nutrient contents, enzymatic and non-enzymatic antioxidants, and ultrastructure. The accumulation of Y in subcellular fractions decreased in the order of cell wall > organelle > soluble fraction. Much more Y was located in cellulose and pectin than in other biomacromolecules. The content of some mineral elements (Mg, Ca, Fe, Mn, and Mo) increased in N. peltata, but there was an opposite effect for P and K. Meanwhile, ascorbate, and catalase activity decreased significantly for all Y concentrations. In contrast, peroxidase activity was induced, while initial rises in superoxide dismutase activity and glutathione content were followed by subsequent declines. Morphological symptoms of senescence, such as chlorosis and damage to chloroplasts and mitochondria, were observed even at the lowest Y concentration. Pigment content decreased as the Y concentration rose and the calculated EC50 and MPC of Y for N. peltata were 2 and 0.2 mg L(-1) after 4 days of exposure, respectively. The results showed that exogenous Y was highly available in water and that its high concentration in water bodies might produce harmful effects on aquatic organisms. N. peltata is proposed as a biomonitor for the assessment of metal pollution in aquatic ecosystems. PMID:24170501

  12. Bioaccumulation of Cs-137 and Co-57 by marine phytoplankton

    Energy Technology Data Exchange (ETDEWEB)

    Heldal, H.E. [Inst. of Marine Research, Bergen (Norway); Stupakoff, I.; Fisher, N.S. [State Univ. of New York, Marine Sciences Research Center, Stone Brook, NY (United States)

    1999-11-01

    Under controlled laboratory conditions we have examined the bioaccumulation of Cs-137 and Co-57 in three prymnesiophytes, the coccolithophorid Emiliania huxleyi and the non-calcareous species Isochrysis galbana and Phaeocystis globosa, and two diatoms Skeletonema costatum and Thalassiosira pseudonana. We measured uptake in growing and non-growing cells, and determined concentration factors on both volume and dry weight basis. For Co-57 uptake in non-growing cells, volume concentration factors (VCF) at equilibrium ranged from 0.2{sup *}10{sup 3} for Emiliana huxleyi to 4{sup *}10{sup 3} for the diatom Thalassiosira pseudonana. For Cs-137 uptake in non-growing cells the VCFs were close to zero. The results suggest that, in contrast to Co, the cycling and bioaccumulation in animals of Cs in marine systems is unlikely to be affected by primary producers. (au)

  13. Integrated testing strategy (ITS) for bioaccumulation assessment under REACH

    DEFF Research Database (Denmark)

    Lombardo, Anna; Roncaglioni, Alessandra; Benfentati, Emilio;

    2014-01-01

    present an ITS for evaluating the bioaccumulation potential of organic chemicals. The scheme includes the use of all available data (also the non-optimal ones), waiving schemes, analysis of physicochemical properties related to the end point and alternative methods (both in silico and in vitro). In vivo...... in a dossier. REACH promotes the use of alternative methods to replace, refine and reduce the use of animal (eco)toxicity testing. Within the EU OSIRIS project, integrated testing strategies (ITSs) have been developed for the rational use of non-animal testing approaches in chemical hazard assessment. Here we...... methods are used only as last resort. Using the ITS, in vivo testing could be waived for about 67% of the examined compounds, but bioaccumulation potential could be estimated on the basis of non-animal methods. The presented ITS is freely available through a web tool. © 2014 Elsevier Ltd....

  14. Bioaccumulation of heavy metals in two wet retention ponds

    DEFF Research Database (Denmark)

    Søberg, Laila C.; Vollertsen, Jes; Blecken, Godecke-Tobias;

    2016-01-01

    Metal accumulation in stormwater ponds may contaminate the inhabiting fauna, thus jeopardizing their ecosystem servicing function. We evaluated bioaccumulation of metals in natural fauna and caged mussel indicator organisms in two wet retention ponds. Mussel cages were distributed throughout...... the ponds to detect bioaccumulation gradients and obtain a time-integrated measure of metal bioavailability. We further investigated if sediment metal concentrations correlate with those in the fauna and mussels. Metal concentrations in the fauna tended to be higher in the ponds than in a reference lake......, but statistical significance was only shown for Cu. Positive correlations were found for some metals in fauna and sediment. Sediment metal concentrations in one pond decreased from inlet to outlet while no gradients were observed in the mussels in either pond. These findings indicate that metal accumulation...

  15. Does aquatic foraging impact head shape evolution in snakes?

    Science.gov (United States)

    Segall, Marion; Cornette, Raphaël; Fabre, Anne-Claire; Godoy-Diana, Ramiro; Herrel, Anthony

    2016-08-31

    Evolutionary trajectories are often biased by developmental and historical factors. However, environmental factors can also impose constraints on the evolutionary trajectories of organisms leading to convergence of morphology in similar ecological contexts. The physical properties of water impose strong constraints on aquatic feeding animals by generating pressure waves that can alert prey and potentially push them away from the mouth. These hydrodynamic constraints have resulted in the independent evolution of suction feeding in most groups of secondarily aquatic tetrapods. Despite the fact that snakes cannot use suction, they have invaded the aquatic milieu many times independently. Here, we test whether the aquatic environment has constrained head shape evolution in snakes and whether shape converges on that predicted by biomechanical models. To do so, we used three-dimensional geometric morphometrics and comparative, phylogenetically informed analyses on a large sample of aquatic snake species. Our results show that aquatic snakes partially conform to our predictions and have a narrower anterior part of the head and dorsally positioned eyes and nostrils. This morphology is observed, irrespective of the phylogenetic relationships among species, suggesting that the aquatic environment does indeed drive the evolution of head shape in snakes, thus biasing the evolutionary trajectory of this group of animals.

  16. Bioaccumulation of PCBs in the cuttlefish Sepia officinalis from seawater, sediment and food pathways

    Energy Technology Data Exchange (ETDEWEB)

    Danis, B. [Laboratoire de Biologie Marine (CP 160-15), Universite Libre de Bruxelles, 50 Av. F.D. Roosevelt, B-1050 Brussels (Belgium)]. E-mail: bdanis@ulb.ac.be; Bustamante, P. [Laboratoire de Biologie et Environnement Marins, UPRES-EA 3168, Universite de La Rochelle, 22 Av. Michel Crepeau, F-17042 La Rochelle Cedex (France); Cotret, O. [Marine Environment Laboratory - International Atomic Energy Agency, 4 Quai Antoine Ier, Monaco, MC-98000 Monaco (Monaco); Teyssie, J.L. [Marine Environment Laboratory - International Atomic Energy Agency, 4 Quai Antoine Ier, Monaco, MC-98000 Monaco (Monaco); Fowler, S.W. [Marine Environment Laboratory - International Atomic Energy Agency, 4 Quai Antoine Ier, Monaco, MC-98000 Monaco (Monaco); Warnau, M. [Marine Environment Laboratory - International Atomic Energy Agency, 4 Quai Antoine Ier, Monaco, MC-98000 Monaco (Monaco)

    2005-03-01

    The cuttlefish Sepia officinalis was selected as a model cephalopod to study PCB bioaccumulation via seawater, sediments and food. Newly hatched, juvenile cuttlefish were exposed for 17 days to environmentally realistic concentrations of {sup 14}C-labeled 2,2',4,4',5,5'-hexachlorobiphenyl (PCB no. 153) (18 ng PCB l{sup -1} seawater; 30 ng PCB g{sup -1} dry wt sediments; Artemia salina exposed to 18 ng PCB l{sup -1} seawater). Accumulation of PCB no. 153 was followed in three body compartments: digestive gland, cuttlebone and the combined remaining tissues. Results showed that (1) uptake kinetics were source- and body compartment-dependent, (2) for each body compartment, the accumulation was far greater when S. officinalis was exposed via seawater, (3) the cuttlebone accumulated little of the contaminant regardless of the source, and (4) the PCB congener showed a similar distribution pattern among the different body compartments following exposure to contaminated seawater, sediment or food with the lowest concentrations in the cuttlebone and the highest in the remaining tissues. The use of radiotracer techniques allowed delineating PCB kinetics in small whole organisms as well as in their separate tissues. The results underscore the enhanced ability of cephalopods to concentrate organic pollutants such as PCBs, and raise the question of potential risk to their predators in contaminated areas. - Bioaccumulation of PCBs by cuttlefish is studied, via seawater, sediments and their food.

  17. Influence of Lipophilicity on the Toxicity of Bisphenol A and Phthalates to Aquatic Organisms.

    Science.gov (United States)

    Mathieu-Denoncourt, Justine; Wallace, Sarah J; de Solla, Shane R; Langlois, Valerie S

    2016-07-01

    Bisphenol A (BPA) and phthalates are among the most popular plasticizers used today and have been reported ubiquitously in surface water, ground water, and sediment. For aquatic organisms, BPA was the most toxic (96 h LC50s) to aquatic invertebrates (0.96-2.70 mg/L) and less toxic to fish (6.8-17.9 mg/L). The toxicity of BPA to amphibians differed among developmental stages, with embryos having an LC50 of 4.6-6.8 mg/L and juveniles 0.50-1.4 mg/L. The toxicity of phthalates is affected by aromatic ring substitution, alkyl chain length, and metabolism. The toxicity (96 h LC50s) of phthalates was similar to aquatic invertebrates (0.46-377 mg/L) and fish (0.48-121 mg/L). In general, the toxicity of phthalates appears to be highest around a log KOW of 6, which corresponds to the highest potential for bioconcentration and bioaccumulation. In conclusion, the lipophilicity of BPA and phthalates influence their toxicity to aquatic species.

  18. Evaluation and network of EC-decision support systems in the field of hydrological dispersion models and of aquatic radioecological research: assessment of environmental models and software

    International Nuclear Information System (INIS)

    The present report describes the results of an assessment of state-of-the-art computerised Decision Support Systems based on environmental models for the management of fresh water ecosystems contaminated by radioactive substances. The models are examined and compared to identify their main features, the application domains, the performances, etc., for a rationale of the entire sector in view of the needs of potential users. A similar assessment was performed for the software products implementing the Decision Support Systems. This work was carried out in the frame of the network EVANET-HYDRA financed by the European Commission

  19. Uptake and bioaccumulation of Cry toxins by an aphidophagous predator.

    Science.gov (United States)

    Paula, Débora P; Andow, David A

    2016-02-01

    Uptake of Cry toxins by insect natural enemies has rarely been considered and bioaccumulation has not yet been demonstrated. Uptake can be demonstrated by the continued presence of Cry toxin after exposure has stopped and gut contents eliminated. Bioaccumulation can be demonstrated by showing uptake and that the concentration of Cry toxin in the natural enemy exceeds that in its food. We exposed larvae of the aphidophagous predator, Harmonia axyridis, to Cry1Ac and Cry1F through uniform and constant tritrophic exposure via an aphid, Myzus persicae, and looked for toxin presence in the pupae. We repeated the experiment using only Cry1F and tested newly emerged adults. Both Cry toxins were detected in pupae, and Cry1F was detected in recently emerged, unfed adults. Cry1Ac was present 2.05 times and Cry1F 3.09 times higher in predator pupae than in the aphid prey. Uptake and bioaccumulation in the third trophic level might increase the persistence of Cry toxins in the food web and mediate new exposure routes to natural enemies. PMID:26686057

  20. Metals bioaccumulation and biomarkers responses in the Neotropical freshwater clam Anodontites trapesialis: Implications for monitoring coal mining areas.

    Science.gov (United States)

    Oliveira, Luciana Fernandes de; Cabral, Millena Terezinha; Vieira, Carlos Eduardo Delfino; Antoniazzi, Matheus Henrique; Risso, Wagner Ezequiel; Martinez, Claudia Bueno Dos Reis

    2016-11-15

    As one of the most impactful industries, coal mining can promote several alterations at surrounding environment. In surface water, elevated concentrations of metals like Mn, Zn, Fe and Al are often observed. Thus, the aim of this study was to investigate the bioaccumulation and the sub-lethal effects of these metals on various organs of the Neotropical bivalve Anodontites trapesialis confined along a stream located near a coal mine, in order to assess a set of biomarkers that could be used for effectively monitoring coal mining areas. Clams were caged, for 96h, at two sites located upstream (Up1 and Up2) and two sites downstream (Dw1 and Dw2) from the mine. Metals bioaccumulation was determined in gills, mantle, digestive gland, muscle and hemolymph and the following biomarkers were measured in A. trapesialis tissues: total antioxidant capacity against peroxyl radicals, metallothionein content, lipid peroxidation (LPO), proteins carbonylation, glutathione S-transferase activity, superoxide dismutase activity and acetylcholinesterase (AChE) activity. The results showed that Al and Fe bioaccumulation in the gills and hemolymph, Al bioaccumulation in the mantle and muscle, increased LPO in the gills (Dw1 and Dw2) and mantle (Dw1), as well as reduced AChE activity in the muscle (Dw1 and Dw2) should be considered effective biomarkers for monitoring coal mining areas. A. trapesialis proved to be an efficient biological model, considering that biomarkers responses were observed in the clams after only 96h of confinement at Dw sites, accordingly this species could be a good candidate for monitoring Neotropical freshwaters. PMID:27453135

  1. Bioaccumulation of arsenic and silver by the caddisfly larvae Hydropsyche siltalai and H. pellucidula

    DEFF Research Database (Denmark)

    Awrahman, Zmnako; Rainbow, Philip S; Smith, Brian D;

    2015-01-01

    , respectively, for H. pellucidula in moderately hard synthetic water at 10 °C. The assimilation efficiencies (±SE) of As and Ag from radiolabeled ingested food were 46.0 ± 7.7% and 75.7 ± 3.6%, respectively, for H. siltalai, and 61.0 ± 4.2% and 52.6 ± 8.6%, respectively, for H. pellucidula. Ag, but not As, AEs......Biodynamic modeling was used to investigate the uptake and bioaccumulation of arsenic and silver from water and food by two Hydropsychid caddisfly larvae: Hydropsyche siltalai and Hydropsyche pellucidula. Radiotracer techniques determined the uptake rate constants of arsenic and silver from water...... and silver concentrations in environmental water and food (suspended particles) samples were measured. Biodynamic models successfully predicted accumulated As and Ag concentrations in resident H. siltalai and H. pellucidula at each site. The models also showed that more than 95% of accumulated As and almost...

  2. Modelling of the transfer of radiocaesium from deposition to lake ecosystems. Report of the VAMP aquatic working group. Part of the IAEA/CEC co-ordinated research programme on the validation of environmental model predictions (VAMP)

    International Nuclear Information System (INIS)

    The environmental impact of releases of radionuclides from nuclear installations can be predicted using assessment models. For such assessments information on their reliability must be provided. Ideally models should be developed and tested using actual data on the transfer of the nuclides which are site specific for the environment being modelled. In the past, generic data have often been taken from environmental contamination that resulted from the fallout from the nuclear weapons testing in the 1950s and 1960s or from laboratory experiments. However, it has always been recognized that there may be differences in the physico-chemical form of the radionuclides from these sources as compared to those that could be released from nuclear installations. Furthermore, weapons fallout was spread over time; it did not provide a single pulse which is generally used in testing models that predict time dependence. On the other hand, the Chernobyl accident resulted in a single pulse, which was detected and measured in a variety of environments throughout Europe. The acquisition of these new data sets justified the establishment of an international programme aimed at collating data from different IAEA Member States and at co-ordinating work on new model testing studies. The IAEA established a Co-ordinated Research Programme (CRP) on 'Validation of Environmental Model Predictions' (VAMP). The principal objectives of the VAMP Co-ordinated Research Programme were: (a) To facilitate the validation of assessment models for radionuclide transfer in the terrestrial, aquatic and urban environments. It is envisaged that this will be achieved by acquiring suitable sets of environmental data from the results of the national research and monitoring programmes established following the Chernobyl release. (b) To guide, if necessary, environmental research and monitoring efforts to acquire data for the validation of models used to assess the most significant radiological exposure pathways

  3. Tunison Laboratory of Aquatic Science

    Data.gov (United States)

    Federal Laboratory Consortium — Tunison Laboratory of Aquatic Science (TLAS), located in Cortland, New York, is a field station of the USGS Great Lakes Science Center (GLSC). TLAS was established...

  4. Does the antibiotic amoxicillin affect haemocyte parameters in non-target aquatic invertebrates? The clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis as model organisms.

    Science.gov (United States)

    Matozzo, Valerio; Bertin, Valeria; Battistara, Margherita; Guidolin, Angelica; Masiero, Luciano; Marisa, Ilaria; Orsetti, Alessandro

    2016-08-01

    Amoxicillin (AMX) is one of the most widely used antibiotics worldwide, and its levels in aquatic ecosystems are expected to be detectable. At present, information concerning the toxic effects of AMX on non-target aquatic organisms, such as bivalves, is scarce. Consequently, in this study, we investigated for the first time the effects of AMX on the haemocyte parameters of two bivalve species, the clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis, which share the same habitat in the Lagoon of Venice, in order to compare the relative sensitivity of the two species. The bivalves were exposed to 100, 200 and 400 μg AMX/L for 1, 3 and 7 days, and the effects on the total haemocyte count (THC), the diameter and volume of the haemocytes, haemocyte proliferation, lactate dehydrogenase (LDH) activity in cell-free haemolymph, the haemolymph pH, and the formation of micronuclei were evaluated. The actual concentrations of AMX in the seawater samples from the experimental tanks were also measured. Overall, the obtained results demonstrated that AMX affected slightly the haemocyte parameters of bivalves. In addition, no clear differences in terms of sensitivity to AMX exposure were recorded between the two bivalve species.

  5. Does the antibiotic amoxicillin affect haemocyte parameters in non-target aquatic invertebrates? The clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis as model organisms.

    Science.gov (United States)

    Matozzo, Valerio; Bertin, Valeria; Battistara, Margherita; Guidolin, Angelica; Masiero, Luciano; Marisa, Ilaria; Orsetti, Alessandro

    2016-08-01

    Amoxicillin (AMX) is one of the most widely used antibiotics worldwide, and its levels in aquatic ecosystems are expected to be detectable. At present, information concerning the toxic effects of AMX on non-target aquatic organisms, such as bivalves, is scarce. Consequently, in this study, we investigated for the first time the effects of AMX on the haemocyte parameters of two bivalve species, the clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis, which share the same habitat in the Lagoon of Venice, in order to compare the relative sensitivity of the two species. The bivalves were exposed to 100, 200 and 400 μg AMX/L for 1, 3 and 7 days, and the effects on the total haemocyte count (THC), the diameter and volume of the haemocytes, haemocyte proliferation, lactate dehydrogenase (LDH) activity in cell-free haemolymph, the haemolymph pH, and the formation of micronuclei were evaluated. The actual concentrations of AMX in the seawater samples from the experimental tanks were also measured. Overall, the obtained results demonstrated that AMX affected slightly the haemocyte parameters of bivalves. In addition, no clear differences in terms of sensitivity to AMX exposure were recorded between the two bivalve species. PMID:27219711

  6. 我国鲜活水产品流通组织模式现状及特征分析%Analysis on the Status and Characteristics of the Organization Model of Fresh Aquatic Products Circulation in China

    Institute of Scientific and Technical Information of China (English)

    李晓红; 金兆国; 卢凤君; 吴慧曼

    2011-01-01

    Based on the analysis of the documents and combined with the field investigation, the organization model of fresh aquatic products circulation is differentiated into three types; market transaction, alliance cooperation and product-transport-sale integration in accordance to the degree of organization. This paper analyzes the status and characters of each type respectively. At last, this paper proposes the key factors which impact the organization model of fresh aquatic products circulation.%在文献分析基础上,结合实地调查,按组织化程度高低把我国鲜活水产品流通组织模式分成了产运销一体化型、市场交易型和联盟合作型3种类型,并分别对各种模式特征进行了分析,最后提出了影响鲜活水产品流通组织模式的关键因素.

  7. Implications of Dynamic Loading and Changing Climate on Mercury Bioaccumulation in a Planktivorous Fish (Orthodon microlepidotus)

    Science.gov (United States)

    Carroll, R. W. H.; Flickinger, A.; Warwick, J. J.; Schumer, R.

    2015-12-01

    A bioenergetic and mercury (Hg) mass balance (BioHg) model is developed for the Sacramento blackfish (Orthodon microlepidotus), a filter feeding cyprinid found in northern California and Nevada. Attention focuses on the Lahontan Reservoir in northern Nevada, which receives a strong temporally varying load of dissolved methylmercury (DMeHg) from the Carson River. Hg loads are the result of contaminated bank erosion during high flows and diffusion from bottom sediments during low flows. Coupling of dynamic reservoir loading with periods of maximum plankton growth and maximum fish consumption rates are required to explain the largest body burdens observed in the planktivore. In contrast, the large body burdens cannot be achieved using average water column concentrations. The United States Bureau of Reclamation has produced future streamflow estimates for 2000-2099 using 112 CMIP3 climate projections and the Variable Infiltration Capacity (VIC) model. These are used to drive a fully dynamic Hg transport model to assess changes in contaminant loading to the reservoir and implications on planktivorous bioaccumulation. Model results suggest the future loads of DMeHg entering the Lahontan Reservoir will decrease most significantly in the spring and summer due to channel width increases and depth decreases in the Carson River which reduce bank erosion over the century. The modeled concentrations of DMeHg in the reservoir are expected to increase during the summer due to a decrease in reservoir volume affecting the concentrations more than the decrease in loads, and the model results show that bioaccumulation levels may increase in the upstream sections of the reservoir while maintaining contamination levels above the federal action limit for human consumption in the lower reservoir.

  8. Biogeochemical analysis of ancient Pacific Cod bone suggests Hg bioaccumulation was linked to paleo sea level rise and climate change

    Directory of Open Access Journals (Sweden)

    Maribeth S. Murray

    2015-02-01

    Full Text Available Deglaciation at the end of the Pleistocene initiated major changes in ocean circulation and distribution. Within a brief geological time, large areas of land were inundated by sea-level rise and today global sea level is 120 m above its minimum stand during the last glacial maximum. This was the era of modern sea shelf formation; climate change caused coastal plain flooding and created broad continental shelves with innumerable consequences to marine and terrestrial ecosystems and human populations. In Alaska, the Bering Sea nearly doubled in size and stretches of coastline to the south were flooded, with regional variability in the timing and extent of submergence. Here we suggest how past climate change and coastal flooding are linked to mercury bioaccumulation that could have had profound impacts on past human populations and that, under conditions of continued climate warming, may have future impacts. Biogeochemical analysis of total mercury (tHg and 13C/15N ratios in the bone collagen of archaeologically recovered Pacific Cod (Gadus macrocephalus bone shows high levels of tHg during early/mid-Holocene. This pattern cannot be linked to anthropogenic activity or to food web trophic changes, but may result from natural phenomena such as increases in productivity, carbon supply and coastal flooding driven by glacial melting and sea-level rise. The coastal flooding could have led to increased methylation of Hg in newly submerged terrestrial land and vegetation. Methylmercury is bioaccumulated through aquatic food webs with attendant consequences for the health of fish and their consumers, including people. This is the first study of tHg levels in a marine species from the Gulf of Alaska to provide a time series spanning nearly the entire Holocene and we propose that past coastal flooding resulting from climate change had the potential to input significant quantities of Hg into marine food webs and subsequently to human consumers.

  9. Mycoloop: chytrids in aquatic food webs

    Directory of Open Access Journals (Sweden)

    Maiko eKagami

    2014-04-01

    Full Text Available Parasites are ecologically significant in various ecosystems through their role in shaping food web structure, facilitating energy transfer, and controlling disease. Here in this review, we mainly focus on parasitic chytrids, the dominant parasites in aquatic ecosystems, and explain their roles in aquatic food webs, particularly as prey for zooplankton. Chytrids have a free-living zoosporic stage, during which they actively search for new hosts. Zoospores are excellent food for zooplankton in terms of size, shape, and nutritional quality. In the field, densities of chytrids can be high, ranging from 101-109 spores L-1. When large inedible phytoplankton species are infected by chytrids, nutrients within host cells are transferred to zooplankton via the zoospores of parasitic chytrids. This new pathway, the ‘mycoloop,’ may play an important role in shaping aquatic ecosystems, by altering sinking fluxes or determining system stability. The grazing of zoospores by zooplankton may also suppress outbreaks of parasitic chytrids. A food web model demonstrated that the contribution of the mycoloop to zooplankton production increased with nutrient availability and was also dependent on the stability of the system. Further studies with advanced molecular tools are likely to discover greater chytrid diversity and evidence of additional mycoloops in lakes and oceans.

  10. Bioaccumulation and removal of {sup 1}`3{sup 7} Cs by algae Gracilaria Greville and preparation of compartimental model; Bioacumulo e eliminacao de {sup 137} Cs pela alga Gracilaria Greville e elaboracao de modelo compartimental

    Energy Technology Data Exchange (ETDEWEB)

    Marchese, Sandra R.M. [Centro Tecnologico da Marinha, Sao Paulo, SP (Brazil); Cunha, Ieda I.L.; Mesquita, Carlos H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1997-12-01

    Cesium-137 may be accumulated by biota and transferred through marine chains so, it is important to quantify the accumulation and elimination of radioactivity at different trophic levels. A series of laboratory radiotracer experiments were performed to study the accumulation na delimination rates of cesium-137 in Gracilaria Greville seaweed. The concentration factor as wellas the biological half time for cesium were determined. A compartimental model (AnaComp Program) was employed to estimate transfer rates between compartiments. (author). 8 refs., 2 figs., 4 tabs.

  11. Tritium in the aquatic environment

    International Nuclear Information System (INIS)

    Tritium is of environmental importance because it is released from nuclear facilities in relatively large quantities and because it has a half life of 12.26 y. Most of the tritium released into the atmosphere eventually reaches the aqueous environment, where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered studies of algae, aquatic macrophytes, invertebrates, fish, and the food chain, were that aquatic organisms incorporate tritium into their tissue-free water very rapidly and reach concentrations near those of the external medium. The rate at which tritium from tritiated water is incorporated into the organic matter of cells is slower than the rate of its incorporation into the tissue-free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster, and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water alone. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the ''carrier'' molecule. No evidence was found that biomagnification of tritium occurs at higher trophic levels. Radiation doses from tritium releases to large populations of humans will most likely come from the consumption of contaminated water rather than contaminated aquatic food products

  12. Tritium in the aquatic environment

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G.; Hoffman, F.O.; Frank, M.L.

    1986-02-01

    Tritium is of environmental importance because it is released from nuclear facilities in relatively large quantities and because it has a half life of 12.26 y. Most of the tritium released into the atmosphere eventually reaches the aqueous environment, where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered studies of algae, aquatic macrophytes, invertebrates, fish, and the food chain, were that aquatic organisms incorporate tritium into their tissue-free water very rapidly and reach concentrations near those of the external medium. The rate at which tritium from tritiated water is incorporated into the organic matter of cells is slower than the rate of its incorporation into the tissue-free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster, and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water alone. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the ''carrier'' molecule. No evidence was found that biomagnification of tritium occurs at higher trophic levels. Radiation doses from tritium releases to large populations of humans will most likely come from the consumption of contaminated water rather than contaminated aquatic food products.

  13. Bioaccumulation of organohalogenated compounds in sharks and rays from the southeastern USA.

    Science.gov (United States)

    Weijs, Liesbeth; Briels, Nathalie; Adams, Douglas H; Lepoint, Gilles; Das, Krishna; Blust, Ronny; Covaci, Adrian

    2015-02-01

    Organohalogenated compounds are widespread in the marine environment and can be a serious threat to organisms in all levels of aquatic food webs, including elasmobranch species. Information about the concentrations of POPs (persistent organic pollutants) and of MeO-PBDEs (methoxylated polybrominated diphenyl ethers) in elasmobranchs is scarce and potential toxic effects are poorly understood. The aims of the present study were therefore to investigate the occurrence of multiple POP classes (PCBs, PBDEs, DDXs, HCB, CHLs) and of MeO-PBDEs in various elasmobranch species from different trophic levels in estuarine and marine waters of the southeastern United States. Overall, levels and patterns of PCBs, PBDEs, DDXs, HCB, CHLs and of MeO-PBDEs varied according to the species, maturity stage, gender and habitat type. The lowest levels of POPs were found in Atlantic stingrays and the highest levels were found in bull sharks. As both species are respectively near the bottom and at top of the trophic web, with juvenile bull sharks frequently feeding on Atlantic stingrays, these findings further suggest a bioaccumulation and biomagnification process with trophic position. MeO-PBDEs were not detected in Atlantic stingrays, but were found in all shark species. HCB was not found in Atlantic stingrays, bonnetheads or lemon sharks, but was detected in the majority of bull sharks examined. Comparison with previous studies suggests that Atlantic stingrays may be experiencing toxic effects of PCBs and DDXs on their immune system. However, the effect of these compounds on the health of shark species remains unclear. PMID:25569844

  14. Mercury Bioaccumulation in the Brazilian Amazonian Tucunares (Cichla sp., Cichlidae, Perciformes

    Directory of Open Access Journals (Sweden)

    Maria Josefina Reyna Kurtz

    2008-08-01

    Full Text Available There are emissions of mercury to the atmosphere, soil and rivers of the Brazilian Amazon stem from many sources. Once in the atmosphere, the metal is oxidized and immediately deposited. In the water, the transformation to methylmercury takes place mostly by the action of microorganisms. The formation of methylmercury increases the dispersion and bioavailability of the element in the aquatic environment. Methylmercury can be assimilated by plankton and enters the food chain. The concentration of mercury increases further up in the trophic levels of the chain and reaches the highest values in carnivorous fishes like tucunare. Therefore, mercury emissions cause the contamination of natural resources and increase risks to the health of regular fish consumers. The objective of this work was to study the bioaccumulation of mercury in tucunares (Cichla sp., top predators of the food chain. The fishes were collected at two locations representative of the Amazonian fluvial ecosystem, in the state of Pará, Brazil, in 1992 and 2001. One location is near a former informal gold mining area. The other is far from the mining area and is considered pristine. Average values of total mercury concentration and accumulation rates for four different collection groups were compared and discussed. Tucunares collected in 2001 presented higher mercury contents and accumulated mercury faster than tucunares collected in 1992 notwithstanding the decline of mining activities in this period. The aggravation of the mercury contamination with time not only in an area where informal gold mining was practiced but also far from this area is confirmed.

  15. Bioaccumulation of Legacy and Emerging Organochlorine Contaminants in Lumbriculus variegatus.

    Science.gov (United States)

    Dang, Viet D; Kroll, Kevin J; Supowit, Samuel D; Halden, Rolf U; Denslow, Nancy D

    2016-07-01

    Freshwater sediment-dwelling Lumbriculus variegatus is known to serve as a vector for the transfer of contaminants from sediments to higher trophic level organisms, but limited data exist on the bioaccumulation of chemicals associated with sediments containing high total organic carbon (TOC). In the current study, sediments from the north shore area of Lake Apopka (Florida, USA), containing very high TOC [39 % (w/w)], were spiked with four chemicals-p,p'-dichlorordiphenyldichloroethylene (p,p'-DDE), dieldrin, fipronil, and triclosan-individually or in a mixture of the four and then used for bioaccumulation studies. Tissue concentrations of chemicals in L. variegatus were measured at 2, 7, 14, 21, and 28 days of exposure, and the bioaccumulation potential was evaluated using biosediment accumulation factors [BSAF (goc/glipid)]. Increase in total body burdens of all four chemicals in L. variegatus was rapid at day 2 and reached a steady-state level after 7 days in both single and mixture experiments. Tissue concentrations of fipronil peaked after 2 days and then decreased by 70 % in sediment experiments suggesting that in addition to the degradation of fipronil that occurred in the sediment, L. variegatus may also be able to metabolize fipronil. The calculated 28-day BSAF values varied among the chemicals and increased in the order fipronil (1.1) < triclosan (1.4) < dieldrin (21.8) < p,p'-DDE (49.8) in correspondence with the increasing degree of their hydrophobicity. The relatively high BSAF values for p,p'-DDE and dieldrin probably resulted from lower-than-expected sorption of chemicals to sediment organic matter either due to the nature of the plant-derived organic matter, as a result of the relatively short equilibration time among the various compartments, or due to ingestion of sediment particles by the worms. PMID:26833202

  16. Estimation of the bioaccumulation potential of a nonchlorinated bisphenol and an ionogenic xanthene dye to Eisenia andrei in field-collected soils, in conjunction with predictive in silico profiling.

    Science.gov (United States)

    Princz, Juliska; Bonnell, Mark; Ritchie, Ellyn; Velicogna, Jessica; Robidoux, Pierre-Yves; Scroggins, Rick

    2014-02-01

    In silico-based model predictions, originating from structural and mechanistic (e.g., transport, bioavailability, reactivity, and binding potential) profiling, were compared against laboratory-derived data to estimate the bioaccumulation potential in earthworms of 2 organic substances (1 neutral, 1 ionogenic) known to primarily partition to soil. Two compounds representative of specific classes of chemicals were evaluated: a nonchlorinated bisphenol containing an -OH group (4,4′-methylenebis[2,6-di-tert-butylphenol] [Binox]), and an ionogenic xanthene dye (2′,4′,5′,7′-tetrabromo-4,5,6,7-tetrachloro-3′,6′-dihydroxy-, disodium salt [Phloxine B]). Soil bioaccumulation studies were conducted using Eisenia andrei and 2 field-collected soils (a clay loam and a sandy soil). In general, the in silico structural and mechanistic profiling was consistent with the observed soil bioaccumulation tests. Binox did not bioaccumulate to a significant extent in E. andrei in either soil type; however, Phloxine B not only accumulated within tissue, but was not depurated from the earthworms during the course of the elimination phase. Structural and mechanistic profiling demonstrated the binding and reactivity potential of Phloxine B; this would not be accounted for using traditional bioaccumulation metrics, which are founded on passive-based diffusion mechanisms. This illustrates the importance of profiling for reactive ionogenic substances; even limited bioavailability combined with reactivity can result in exposures to a hazardous substance not predictable by traditional in silico modeling methods.

  17. Estimation of the bioaccumulation potential of a nonchlorinated bisphenol and an ionogenic xanthene dye to Eisenia andrei in field-collected soils, in conjunction with predictive in silico profiling.

    Science.gov (United States)

    Princz, Juliska; Bonnell, Mark; Ritchie, Ellyn; Velicogna, Jessica; Robidoux, Pierre-Yves; Scroggins, Rick

    2014-02-01

    In silico-based model predictions, originating from structural and mechanistic (e.g., transport, bioavailability, reactivity, and binding potential) profiling, were compared against laboratory-derived data to estimate the bioaccumulation potential in earthworms of 2 organic substances (1 neutral, 1 ionogenic) known to primarily partition to soil. Two compounds representative of specific classes of chemicals were evaluated: a nonchlorinated bisphenol containing an -OH group (4,4′-methylenebis[2,6-di-tert-butylphenol] [Binox]), and an ionogenic xanthene dye (2′,4′,5′,7′-tetrabromo-4,5,6,7-tetrachloro-3′,6′-dihydroxy-, disodium salt [Phloxine B]). Soil bioaccumulation studies were conducted using Eisenia andrei and 2 field-collected soils (a clay loam and a sandy soil). In general, the in silico structural and mechanistic profiling was consistent with the observed soil bioaccumulation tests. Binox did not bioaccumulate to a significant extent in E. andrei in either soil type; however, Phloxine B not only accumulated within tissue, but was not depurated from the earthworms during the course of the elimination phase. Structural and mechanistic profiling demonstrated the binding and reactivity potential of Phloxine B; this would not be accounted for using traditional bioaccumulation metrics, which are founded on passive-based diffusion mechanisms. This illustrates the importance of profiling for reactive ionogenic substances; even limited bioavailability combined with reactivity can result in exposures to a hazardous substance not predictable by traditional in silico modeling methods. PMID:24173968

  18. Effects of sedimentary soot-like materials on bioaccumulation and sorption of polychlorinated biphenyls

    NARCIS (Netherlands)

    Jonker, M.T.O.; Hoenderboom, A.M.; Koelmans, A.A.

    2004-01-01

    Bioaccumulation of hydrophobic organic chemicals from sediments containing soot or sootlike materials has been hypothesized to be limited by strong sorption of the chemicals to the soot matrixes. To test this hypothesis, we quantified bioaccumulation of 11 polychlorinated biphenyls (PCBs) into the a

  19. Bioaccumulation of total mercury in the earthworm Eisenia andrei.

    Science.gov (United States)

    Le Roux, Shirley; Baker, Priscilla; Crouch, Andrew

    2016-01-01

    Earthworms are a major part of the total biomass of soil fauna and play a vital role in soil maintenance. They process large amounts of plant and soil material and can accumulate many pollutants that may be present in the soil. Earthworms have been explored as bioaccumulators for many heavy metal species such as Pb, Cu and Zn but limited information is available for mercury uptake and bioaccumulation in earthworms and very few report on the factors that influence the kinetics of Hg uptake by earthworms. It is known however that the uptake of Hg is strongly influenced by the presence of organic matter, hence the influence of ligands are a major factor contributing to the kinetics of mercury uptake in biosystems. In this work we have focused on the uptake of mercury by earthworms (Eisenia andrei) in the presence of humic acid (HA) under varying physical conditions of pH and temperature, done to assess the role of humic acid in the bioaccumulation of mercury by earthworms from soils. The study was conducted over a 5-day uptake period and all earthworm samples were analysed by direct mercury analysis. Mercury distribution profiles as a function of time, bioaccumulation factors (BAFs), first order rate constants and body burden constants for mercury uptake under selected conditions of temperature, pH as well as via the dermal and gut route were evaluated in one comprehensive approach. The results showed that the uptake of Hg was influenced by pH, temperature and the presence of HA. Uptake of Hg(2+) was improved at low pH and temperature when the earthworms in soil were in contact with a saturating aqueous phase. The total amount of Hg(2+) uptake decreased from 75 to 48 % as a function of pH. For earthworms in dry soil, the uptake was strongly influenced by the presence of the ligand. Calculated BAF values ranged from 0.1 to 0.8. Mercury uptake typically followed first order kinetics with rate constants determined as 0.2 to 1 h(-1). PMID:27347466

  20. Bioaccumulation of ergovaline in bovine lateral saphenous veins in vitro.

    Science.gov (United States)

    Klotz, J L; Kirch, B H; Aiken, G E; Bush, L P; Strickland, J R

    2009-07-01

    Ergot alkaloids have been associated with vasoconstriction in grazing livestock affected by the fescue toxicosis syndrome. Previous in vitro investigations studying how ergot alkaloids caused vasoconstriction have shown that ergovaline has a distinct receptor affinity and sustained contractile response. A similar contractile response has not been noted for lysergic acid. The objectives of this study were to determine if repetitive in vitro exposure of bovine lateral saphenous vein to lysergic acid or ergovaline would result in an increasing contractile response and if a measurable bioaccumulation of the alkaloids in the vascular tissue occurs over time. Segments of vein were surgically biopsied from healthy, Angus x Brangus cross-bred, fescue-naïve yearling heifers (n = 16) or collected from healthy mixed breed and sex cattle immediately after slaughter (n = 12) at a local abattoir. Veins were trimmed of excess fat and connective tissue, sliced into cross-sections, and suspended in a myograph chamber containing 5 mL of oxygenated Krebs-Henseleit buffer (95% O(2)/5% CO(2); pH = 7.4; 37 degrees C). Contractile responses to repetitive additions of ergovaline (1 x 10(-9) and 1 x 10(-7) M) and lysergic acid (1 x 10(-5) and 1 x 10(-4) M) were evaluated using the biopsied veins. For the bioaccumulation experiments, veins collected at the abattoir underwent repetitive additions of 1 x 10(-7) M ergovaline and 1 x 10(-5) M lysergic acid and the segments were removed after every 2 additions and media rinses for alkaloid quantification via HPLC/mass spectrometry. Contractile data were normalized as a percentage of contractile response induced by a reference dose of norepinephrine (1 x 10(-4) M). Repetitive additions of 1 x 10(-9) M ergovaline and 1 x 10(-5) and 1 x 10(-4) M lysergic acid resulted in contractile response with a negative slope (P < 0.02). In contrast, repetitive addition of 1 x 10(-7) M ergovaline resulted in a contractile response that increased with each

  1. Flows of dioxins and furans in coastal food webs: inverse modeling, sensitivity analysis, and applications of linear system theory.

    Science.gov (United States)

    Saloranta, Tuomo M; Andersen, Tom; Naes, Kristoffer

    2006-01-01

    Rate constant bioaccumulation models are applied to simulate the flow of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the coastal marine food web of Frierfjorden, a contaminated fjord in southern Norway. We apply two different ways to parameterize the rate constants in the model, global sensitivity analysis of the models using Extended Fourier Amplitude Sensitivity Test (Extended FAST) method, as well as results from general linear system theory, in order to obtain a more thorough insight to the system's behavior and to the flow pathways of the PCDD/Fs. We calibrate our models against observed body concentrations of PCDD/Fs in the food web of Frierfjorden. Differences between the predictions from the two models (using the same forcing and parameter values) are of the same magnitude as their individual deviations from observations, and the models can be said to perform about equally well in our case. Sensitivity analysis indicates that the success or failure of the models in predicting the PCDD/F concentrations in the food web organisms highly depends on the adequate estimation of the truly dissolved concentrations in water and sediment pore water. We discuss the pros and cons of such models in understanding and estimating the present and future concentrations and bioaccumulation of persistent organic pollutants in aquatic food webs.

  2. Flows of dioxins and furans in coastal food webs: inverse modeling, sensitivity analysis, and applications of linear system theory.

    Science.gov (United States)

    Saloranta, Tuomo M; Andersen, Tom; Naes, Kristoffer

    2006-01-01

    Rate constant bioaccumulation models are applied to simulate the flow of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the coastal marine food web of Frierfjorden, a contaminated fjord in southern Norway. We apply two different ways to parameterize the rate constants in the model, global sensitivity analysis of the models using Extended Fourier Amplitude Sensitivity Test (Extended FAST) method, as well as results from general linear system theory, in order to obtain a more thorough insight to the system's behavior and to the flow pathways of the PCDD/Fs. We calibrate our models against observed body concentrations of PCDD/Fs in the food web of Frierfjorden. Differences between the predictions from the two models (using the same forcing and parameter values) are of the same magnitude as their individual deviations from observations, and the models can be said to perform about equally well in our case. Sensitivity analysis indicates that the success or failure of the models in predicting the PCDD/F concentrations in the food web organisms highly depends on the adequate estimation of the truly dissolved concentrations in water and sediment pore water. We discuss the pros and cons of such models in understanding and estimating the present and future concentrations and bioaccumulation of persistent organic pollutants in aquatic food webs. PMID:16494250

  3. An aquatic ecosystem in space.

    Science.gov (United States)

    Voeste, D; Andriske, M; Paris, F; Levine, H G; Blum, V

    1999-07-01

    The Closed Equilibrated Biological Aquatic System (CEBAS) Mini-Module experiment was designed to study aquatic ecosystem performance within a middeck locker on the Space Shuttle. CEBAS was flown aboard STS-89 in January 1998 with a population of four pregnant Xiphophorus helleri female fish and eleven adult Biomphalaria glabrata snails in the first compartment and 200 juvenile X. helleri and 48 adult and juvenile B. glabrata in the second compartment. A plant compartment contained eleven snails and 53 g of the aquatic angiosperm Ceratophyllum demersum. During the flight, Ceratophyllum fresh weight increased from 53 g to 117 g. All adult fish and 65 juveniles survived the flight experiment and 37 adult snails and 40 newly laid snail spawn packs were recovered after the flight. Oxygen production and pH were as expected.

  4. Bioaccumulation and toxicity of selenium during a life-cycle exposure with desert pupfish (Cyprinodon macularius)

    Science.gov (United States)

    Besser, John M.; Brumbaugh, William G.; Papoulias, Diana M.; Ivey, Chris D.; Kunz, James L.; Annis, Mandy; Ingersoll, Christopher G.

    2012-01-01

    Populations of desert pupfish (Cyprinodon macularius; pupfish), a federally-listed endangered species, inhabit irrigation drains in the Imperial Valley agricultural area of southern California. These drains have varying degrees of selenium (Se) contamination of water, sediment, and aquatic biota. Published Se toxicity studies suggest that these levels of Se contamination may pose risk of chronic toxicity to Se-sensitive fish, but until recently there have been no studies of the chronic toxicity of Se to desert pupfish.A life-cycle Se exposure with pupfish was conducted to estimate dietary and tissue thresholds for toxic effects of Se on all life stages. The dietary exposure was based on live oligochaete worms (Lumbriculus variegatus) dosed with Se by a laboratory food chain based on selenized yeast. Oligochaetes readily accumulated Se from mixtures of selenized and control yeasts. The protocol for dosing oligochaetes for pupfish feeding studies included long-term (at least 28 days) feeding of a low-ration of yeast mixtures to large batches of oligochaetes. Oligochaetes were dosed at five Se levels in a 50-percent dilution series. Pupfish were simultaneously fed Se-dosed oligochaetes and exposed to a series of Se concentrations in water (consisting of 85 percent selenate and 15 percent selenite) to produce exposures that were consistent with Se concentrations and speciation in pupfish habitats. The nutritional characteristics of oligochaete diets were consistent across the range of oligochaete Se concentrations tested.The life-cycle exposure started with laboratory-cultured juvenile pupfish that were exposed to Se through sexual maturation and reproduction (150 days; F0 exposure). The Se exposure continued with eggs, larvae, and juveniles produced by Se-exposed parents (79 days; F1 exposure). Selenium exposure (water and diets), Se bioaccumulation (whole-body and eggs), and toxicity endpoints (juvenile and adult survival and growth; egg production and hatching

  5. Bioaccumulation potential of contaminants from bedded and suspended Oakland Harbor deepening project sediments to San Francisco Bay flatfish and bivalve mollusks. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, V.A.; Clarke, J.U.; Lutz, C.H.; Jarvis, A.S.; Mulhearn, B.

    1994-08-01

    The Oakland Harbor Deepening Project (OHDP) has been on hold since 1987 due to public and resource agency concerns regarding further disposal of dredged sediments within San Francisco (SF) Bay. Dispersal of the fines fraction throughout the Bay was thought to occur following disposal operations at the Alcatraz site, resulting in transport of contaminants throughout the Bay system. The study described in this report was designed to address the potential for contaminant uptake in estuarine organisms through exposure to suspended and bedded OHDP sediments. Bioaccumulation that occurred from these sediments was put into perspective with bioaccumulation from sediments normally resuspended in the Bay by natural processes, and from a demonstrably contaminated sediment. Indigenous SF Bay organisms were exposed to either bedded or suspended sediment in replicate experimental units of the Flow-through Aquatic Toxicology Exposure System (FATES) at the WES. Sediments and tissues were analyzed for a suite of contaminants, including organotins, polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides and DDE, and ten metals.

  6. Metal bioaccumulation in the Mediterranean barbel (Barbus meridionalis) in a Mediterranean river receiving effluents from urban and industrial wastewater treatment plants.

    Science.gov (United States)

    Maceda-Veiga, Alberto; Monroy, Mario; de Sostoa, Adolfo

    2012-02-01

    Although sewage treatment plants (STPs) play a crucial role in maintaining the water quality and flow of Mediterranean rivers, particularly during drought periods, few studies have addressed their impact on aquatic fauna. Here we analyzed the role of STPs as a source of metals in the Ripoll River, a heavily urbanized and industrialized watercourse with a long history of anthropogenic disturbance. For this purpose, we measured iron, mercury, cadmium, zinc, lead, nickel and copper accumulation in the liver and muscle of the Mediterranean barbel, Barbus meridionalis and also the concentrations of these metals in the river water. Industrial and urban sewage treatment plants are source of metals in Ripoll River but the former mainly increases Zn and Ni values. Significant differences in metal bioaccumulation between reference and polluted sites were detected. Nevertheless, there was only a significant positive relationship between bioaccumulation of Cu and Hg, and their concentration in water. In addition, the lead concentration in fish was not clearly associated with the presence of STPs. On the basis of morphometric parameters, the hepato-somatic index was the only one denoting significant differences between polluted and references sites. Given that fish are key elements in food webs, recreational fishing is practice in this area and that river water is used for agricultural purposes, we recommend long-term studies to analyze the impact of metal pollution in this river.

  7. Study on pricing model of aquatic environment quality resources%水环境质量资源定价模型研究

    Institute of Scientific and Technical Information of China (English)

    王俊能; 许振成; 彭晓春; 胡习邦; 张修玉

    2011-01-01

    在水环境质量资源的价格分析中,引入"级差地租"理论,以水质差异而造成的水价不同作为水环境质量资源的定量依据,结合模糊综合评判法,建立一种新的适用于复杂且模糊的多指标评价体系的环境质量资源定价方法.以广州流溪河为例,分析了各河段的水质价格,分析表明,本文提供的模型可为合理调整水价,修正水资源核算,制定水资源管理的相关政策提供依据.%Using price difference caused by water quality difference as the quantifying base of water environmental quality, introducing differential rent theory and combining with fuzzy comprehensive evaluation, a pricing method of aquatic environment quality resources was proposed.This new pricing method was applicable to complicated and fuzzy multi-index evaluation system.Taking Liuxi River in Guangzhou as an example, water quality price in each river section was calculated, which provided a base for rationally adjusting water price, correcting water resources checking and making relevant police of water resources management.

  8. Effects of the antihistamine diphenhydramine on selected aquatic organisms.

    Science.gov (United States)

    Berninger, Jason P; Du, Bowen; Connors, Kristin A; Eytcheson, Stephanie A; Kolkmeier, Mark A; Prosser, Krista N; Valenti, Theodore W; Chambliss, C Kevin; Brooks, Bryan W

    2011-09-01

    In recent years pharmaceuticals have been detected in aquatic systems receiving discharges of municipal and industrial effluents. Although diphenhydramine (DPH) has been reported in water, sediment, and fish tissue, an understanding of its impacts on aquatic organisms is lacking. Diphenhydramine has multiple modes of action (MOA) targeting the histamine H1, acetylcholine (ACh), and 5-HT reuptake transporter receptors, and as such is used in hundreds of pharmaceutical formulations. The primary objective of this study was to develop a baseline aquatic toxicological understanding of DPH using standard acute and subchronic methodologies with common aquatic plant, invertebrate, and fish models. A secondary objective was to test the utility of leveraging mammalian pharmacology information to predict aquatic toxicity thresholds. The plant model, Lemna gibba, was not adversely affected at exposures as high as 10 mg/L. In the fish model, Pimephales promelas, pH affected acute toxicity thresholds and feeding behavior was more sensitive (no-observed-effect concentration = 2.8 µg/L) than standardized survival or growth endpoints. This response threshold was slightly underpredicted using a novel plasma partitioning approach and a mammalian pharmacological potency model. Interestingly, results from both acute mortality and subchronic reproduction studies indicated that the model aquatic invertebrate, Daphnia magna, was more sensitive to DPH than the fish model. These responses suggest that DPH may exert toxicity in Daphnia through ACh and histamine MOAs. The D. magna reproduction no-observed-effect concentration of 0.8 µg/L is environmentally relevant and suggests that additional studies of more potent antihistamines and antihistamine mixtures are warranted. PMID:21647947

  9. Sediment Bioaccumulation Test with Lumbriculus variegatus: Effects of Organism Loading.

    Science.gov (United States)

    Burkhard, Lawrence P; Hubin-Barrows, Dylan; Billa, Nanditha; Highland, Terry L; Hockett, James R; Mount, David R; Norberg-King, Teresa J

    2016-07-01

    At contaminated sediment sites, the bioavailability of contaminants in sediments is assessed using sediment-bioaccumulation tests with Lumbriculus variegates (Lv). The testing protocols recommend that ratio of total organic carbon (TOC) in sediment to L. variegatus (dry weight) (TOC/Lv) should be no less than 50:1. Occasionally, this recommendation is not followed, especially with sediments having low TOC, e.g., polychlorinated biphenyls (PCBs) in the L. variegatus were measured in six of the seven sediments tested, and differences in PCB residues among loading ratios across all sediments were small, i.e., ±50 %, from those measured at the minimum recommended ratio of 50:1 TOC/Lv. In all sediment, PCB residues increased with increasing loading of the organisms for the mono-, di-, and tri-chloro-PCBs. For tetra-chloro and heavier PCBs, residues increased with increasing loading of organisms for only two of the six sediments. PCB residues were not significantly different between TOC/Lv loadings of 50:1 and mid-20:1 ratios indicating that equivalent results can be obtained with TOC/Lv ratios into the mid-20:1 ratios. Overall, the testing results suggest that when testing recommendation of 50:1 TOC/Lv is not followed, potential biases in the biota-sediment accumulations factors from the sediment-bioaccumulation test will be small. PMID:27165691

  10. Bioaccumulation of hexachlorobenzene in Eisenia foetida at different aging stages

    Institute of Scientific and Technical Information of China (English)

    GAO Hongjian

    2009-01-01

    The impacts of contact time on the extractability, the availability of hexachlorobenzene (HCB) in different soils (paddy soil, red soil, and fluvo-aquic soil) and bioaccurnulation in earthworm Eisenia foetida were investigated under controlled conditions in laboratory. Results indicated that the aging rate of HCB displaying a biphasic character in different soils: a rapid aging in the first 60 d followed by a slow aging in the next 120 d incubation time. Moreover, most of extractable HCB (about 90%) decline occurred in the first 60 d after HCB was spiked into the soils. The aging rate of HCB in the paddy soil was higher than that in the fluvo-aquic soil or the red soil. The amount of HCB accumulated in the earthworms and its accumulative ability, expressed as a bioaccumulation factor (BAF), declined as the aging time increased from 1 to 180 d. Although the extractable HCB decreased with increasing residence time in soil, much of HCB could still be accumulated by earthworms (457.6-984.3 ng/g) through bioaccumulation, which poses a potential risk to soil ecological safety.

  11. Bioaccumulation Pattern of Mercury in Bacopa monnieri (L. Pennell

    Directory of Open Access Journals (Sweden)

    Hussain K

    2012-05-01

    Full Text Available Bioaccumulation pattern of mercury was studied in Bacopa monnieri plants cultivated in Hoagland nutrient medium artificially contaminated with 5 and 10μM HgCl2. Mercury content of roots, stem and leaves were analysed using Atomic Absorption Spectrophotometry (AAS. During a period 12 days of growth, more accumulation was noticed in roots followed by stem and leaves. Repeated addition of HgCl2 and enhanced growth period up to 50 days showed only negligible increase in accumulation maintaining a threshold level of mercury in the root. When a comparison was done between the quantities of HgCl2 added to the growth medium and the sum of total accumulation of the plant and content present in the residual medium, a significant quantity of mercury is found to be lost presumably through the process of phytovolatilization from the plant. Studies on the effect of pH on bioaccumulation of mercury showed that acidic pH enhanced accumulation rate and hence for phytoremediation technology ‘chlorination’ is recommended whereas for medicinal purpose, Bacopa monnieri plants can be harvested after ‘liming’ to increase the pH and thereby reducing accumulation rate of mercury.

  12. Learning from data for aquatic and geothenical environments

    NARCIS (Netherlands)

    Bhattacharya, B.

    2005-01-01

    The book presents machine learning as an approach to build models that learn from data, and that can be used to complement the existing modelling practice in aquatic and geotechnical environments. It provides concepts of learning from data, and identifies segmentation (clustering), classification, r

  13. Morbillivirus infections in aquatic mammals

    NARCIS (Netherlands)

    I.K.G. Visser (Ilona); M.F. van Bressem; T. Barrett (Thomas); A.D.M.E. Osterhaus (Ab)

    1993-01-01

    textabstractInfections with morbilliviruses have caused heavy losses among different populations of aquatic mammals during the last 5 years. Two different morbilliviruses were isolated from disease outbreaks among seals in Europe and Siberia: phocid distemper virus-1 (PDV-1) and phocid distemper vir

  14. KINETICS AND EQUILIBRIUM PARAMETERS OF BIOSORPTION AND BIOACCUMULATION OF LEAD IONS FROM AQUEOUS SOLUTIONS BY TRICHODERMA LONGIBRACHIATUM

    Directory of Open Access Journals (Sweden)

    Enitan S. Balogun

    2012-04-01

    Full Text Available Biosorption and bioaccumulation of Lead ions (Pb(II by Trichoderma longibrachiatum were investigated in a batch system. The effects of some important parameters such as pH, initial metal concentration, temperature and inoculum concerntration on biosorption capacity were also studied. The maximum biosorption capacity of Trichoderma longibrachiatum was at 25 ppm of lead, showed 100 % removal at pH 7 and 25 oC after fifteen days. Biosorption equilibrium was established in 150 minutes. The process fitted well into pseudo second order kinetic model and was best explained by Langmuir isotherm.

  15. Relevance and analysis of traffic related platinum group metals (Pt, Pd, Rh) in the aquatic biosphere, with emphasis on palladium.

    Science.gov (United States)

    Sures, Bernd; Zimmermann, Sonja; Messerschmidt, Jürgen; von Bohlen, Alex

    2002-10-01

    Following the introduction of automobile catalysts in the middle of the Eighties in Germany there is an increasing emission of the platinum-group-metals (PGM) platinum (Pt), palladium (Pd) and rhodium (Rh). Still, it remains unclear if these metals are bioavailable for aquatic animals and to which extent they accumulate in the aquatic biosphere. Zebra mussels (Dreissena polymorpha) were maintained in water containing road dust at a concentration of 1 kg/10 l. Following an exposure period of 26 weeks, soft tissues of the mussels were analysed applying adsorptive cathodic stripping voltammetry (ACSV) for the determination of Pt and Rh and total-reflection X-ray fluorescence analysis after co-precipitation of Pd with mercury. This experiment revealed for the first time that all the three catalyst emitted metals were accumulated by mussels. The bioaccumulation increased in the following manner: Rh < Pt < Pd. Thus, the application of sentinel organisms in combination with modern trace analytical procedures in environmental impact studies does allow an assessment of the distribution and the degree of bioaccumulation of PGM in the environment, which is highly appreciated. PMID:12463686

  16. Proactive aquatic ecotoxicological assessment of room-temperature ionic liquids

    Science.gov (United States)

    Kulacki, K.J.; Chaloner, D.T.; Larson, J.H.; Costello, D.M.; Evans-White, M. A.; Docherty, K.M.; Bernot, R.J.; Brueseke, M.A.; Kulpa, C.F.; Lamberti, G.A.

    2011-01-01

    Aquatic environments are being contaminated with a myriad of anthropogenic chemicals, a problem likely to continue due to both unintentional and intentional releases. To protect valuable natural resources, novel chemicals should be shown to be environmentally safe prior to use and potential release into the environment. Such proactive assessment is currently being applied to room-temperature ionic liquids (ILs). Because most ILs are water-soluble, their effects are likely to manifest in aquatic ecosystems. Information on the impacts of ILs on numerous aquatic organisms, focused primarily on acute LC50 and EC50 endpoints, is now available, and trends in toxicity are emerging. Cation structure tends to influence IL toxicity more so than anion structure, and within a cation class, the length of alkyl chain substituents is positively correlated with toxicity. While the effects of ILs on several aquatic organisms have been studied, the challenge for aquatic toxicology is now to predict the effects of ILs in complex natural environments that often include diverse mixtures of organisms, abiotic conditions, and additional stressors. To make robust predictions about ILs will require coupling of ecologically realistic laboratory and field experiments with standard toxicity bioassays and models. Such assessments would likely discourage the development of especially toxic ILs while shifting focus to those that are more environmentally benign. Understanding the broader ecological effects of emerging chemicals, incorporating that information into predictive models, and conveying the conclusions to those who develop, regulate, and use those chemicals, should help avoid future environmental degradation. ?? 2011 Bentham Science Publishers Ltd.

  17. Aquatic Macrophyte Risk Assessment for Pesticides

    NARCIS (Netherlands)

    Maltby, L.; Arnold, D.; Arts, G.H.P.; Davies, J.; Heimbach, F.; Pickl, C.; Poulsen, V.

    2009-01-01

    Given the essential role that primary producers play in aquatic ecosystems, it is imperative that the potential risk of pesticides to the structure and functioning of aquatic plants is adequately assessed. This book discusses the assessment of the risk of pesticides with herbicidal activity to aquat

  18. Sea Level Affecting Marshes Model (SLAMM)‐New Functionality for Predicting Changes in Distribution of Submerged Aquatic Vegetation in Response to Sea Level Rise.Version 1.0

    Science.gov (United States)

    Submerged aquatic vegetation (SAV) is an ecologically important habitat world-wide. In Pacific Northwest (PNW) estuaries, SAV in the lower intertidal and shallow subtidal habitats are dominated by the native seagrass, Zostera marina also referred to as submerged aquatic vegetati...

  19. Role of metal mixtures (Ca, Cu and Pb) on Cd bioaccumulation and phytochelatin production by Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    The goal of the study was to determine whether metal uptake and biological effects could be predicted by free ion concentrations when organisms were exposed to Cd and a second metal. Bioaccumulation and algal phytochelatin (PC) concentrations were determined for Chlamydomonas reinhardtii following a 6-h exposure. Bioaccumulation results, after six hours of exposure, showed that Cd uptake decreased in the presence of relatively high concentrations of Ca, Cu and Pb, however, Cd bioaccumulation increased in the presence of ca. equimolar concentrations of Cu. A good correlation was observed between the production of PCs and the amount of metals bioaccumulated for the binary mixtures of Cd–Pb and Cd–Cu, but not the Cd–Ca mixture. Overall, the results suggested that, in the case of mixtures, bioaccumulated metal rather than free ion concentrations would be a better predictor of biological effect. -- Highlights: •Cd bioaccumulation and phytochelatin production were evaluated for metal mixtures. •Bioaccumulated metal rather than free ion was a better predictor of biological effect. •Calcium additions decreased Cd bioaccumulation but increased phytochelatin production. •Copper additions increased Cd bioaccumulation and phytochelatin production. •Lead additions had little effect on either Cd bioaccumulation or phytochelatin production. -- In metal mixtures containing Cd and Ca, Pb or Cu, bioaccumulated metal rather than free ion was a better predictor of biological effect

  20. IMPROVED VALUATION OF ECOLOGICAL BENEFITS ASSOCIATED WITH AQUATIC LIVING RESOURCES: DEVELOPMENT AND TESTING OF INDICATOR-BASED STATED PREFERENCE VALUATION AND TRANSFER

    Science.gov (United States)

    In addition to development and systematic qualitative/quantitative testing of indicator-based valuation for aquatic living resources, the proposed work will improve interdisciplinary mechanisms to model and communicate aquatic ecosystem change within SP valuation—an area...

  1. Toxicity evaluation of copper oxide bulk and nanoparticles in Nile tilapia, Oreochromis niloticus, using hematological, bioaccumulation and histological biomarkers.

    Science.gov (United States)

    Abdel-Khalek, Amr A; Badran, Shereen R; Marie, Mohamed-Assem S

    2016-08-01

    The increased industrial applications of nanoparticles (NPs) augment the possibility of their deposition into aquatic ecosystems and threatening the aquatic life. So, this study aimed to provide a comparable toxicological effects of nano-CuO and bulk CuO on a common freshwater fish, Oreochromis niloticus. Fish were exposed to two selected doses (1/10 and 1/20 of the LC50/96 h) of both nano-/bulk CuO for 30 days. Based on the studied hematological parameters (RBCs count, hemoglobin content and hematocrit%), the two selected concentrations of CuO in their nano- and bulk sizes were found to induce significant decrease in all studied parameters. But, nano-CuO-treated fish showed the maximum decrease in all recorded parameters among the all studied groups especially at the low concentration of 1/20 LC50/96 h. Hematological status was also confirmed using the calculated blood indices (MCV, MHC and MCHC). In case of bulk CuO-treated groups, the significant decrease in the studied hematological parameters was not followed by any change in MCV and MCH (normocytic anemia), while fish that exposed to NPs showed a significant increase in all calculated blood parameters reflecting erythrocytes swelling which is related to the intracellular osmotic disorders (macrocytic anemia). Regarding metal bioaccumulation factor, the results showed that CuO NPs had more efficiency to internalize fish tissues (liver, kidneys, gills, skin and muscle). The accumulation pattern of Cu metal was ensured by histopathological investigation of liver, kidneys and gills. The histopathological analysis revealed various alterations that varied between adaptation responses and permanent tissue damage.

  2. Toxicity evaluation of copper oxide bulk and nanoparticles in Nile tilapia, Oreochromis niloticus, using hematological, bioaccumulation and histological biomarkers.

    Science.gov (United States)

    Abdel-Khalek, Amr A; Badran, Shereen R; Marie, Mohamed-Assem S

    2016-08-01

    The increased industrial applications of nanoparticles (NPs) augment the possibility of their deposition into aquatic ecosystems and threatening the aquatic life. So, this study aimed to provide a comparable toxicological effects of nano-CuO and bulk CuO on a common freshwater fish, Oreochromis niloticus. Fish were exposed to two selected doses (1/10 and 1/20 of the LC50/96 h) of both nano-/bulk CuO for 30 days. Based on the studied hematological parameters (RBCs count, hemoglobin content and hematocrit%), the two selected concentrations of CuO in their nano- and bulk sizes were found to induce significant decrease in all studied parameters. But, nano-CuO-treated fish showed the maximum decrease in all recorded parameters among the all studied groups especially at the low concentration of 1/20 LC50/96 h. Hematological status was also confirmed using the calculated blood indices (MCV, MHC and MCHC). In case of bulk CuO-treated groups, the significant decrease in the studied hematological parameters was not followed by any change in MCV and MCH (normocytic anemia), while fish that exposed to NPs showed a significant increase in all calculated blood parameters reflecting erythrocytes swelling which is related to the intracellular osmotic disorders (macrocytic anemia). Regarding metal bioaccumulation factor, the results showed that CuO NPs had more efficiency to internalize fish tissues (liver, kidneys, gills, skin and muscle). The accumulation pattern of Cu metal was ensured by histopathological investigation of liver, kidneys and gills. The histopathological analysis revealed various alterations that varied between adaptation responses and permanent tissue damage. PMID:26947705

  3. Mercury bioaccumulation in the food web of Three Gorges Reservoir (China): Tempo-spatial patterns and effect of reservoir management

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jun [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Zhou, Qiong, E-mail: hainan@mail.hzau.edu.cn [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Yuan, Gailing; He, Xugang [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Xie, Ping [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)

    2015-09-15

    Tempo-spatial patterns of mercury bioaccumulation and tropho-dynamics, and the potential for a reservoir effect were evaluated in the Three Gorges Reservoir (TGR, China) from 2011 to 2012, using total mercury concentrations (THg) and stable isotopes (δ{sup 13}C and δ{sup 15}N) of food web components (seston, aquatic invertebrates and fish). Hg concentrations in aquatic invertebrates and fish indicated a significant temporal trend associated with regular seasonal water-level manipulation. This includes water level lowering to allow for storage of water during the wet season (summer); a decrease of water levels from September to June providing a setting for flood storage. Hg concentrations in organisms were the highest after flooding. Higher Hg concentrations in fish were observed at the location farthest from the dam. Hg concentrations in water and sediment were correlated. Compared with the reservoirs of United States and Canada, TGR had lower trophic magnification factors (0.046–0.066), that are explained primarily by organic carbon concentrations in sediment, and the effect of “growth dilution”. Based on comparison before and after the impoundment of TGR, THg concentration in biota did not display an obvious long-term reservoir effect due to (i) short time since inundation, (ii) regular water discharge associated with water-level regulation, and/or (iii) low organic matter content in the sediment. - Highlights: • Hg concentrations were measured in biota of the main stem of 3 Gorges Reservoir. • Fish Hg concentration post-flood period > pre-flood period > flood period. • Fish Hg concentrations were the highest farthest from the dam. • THg in fish 2 years after inundation were the same as before impoundment. • Low biomagnification was ascribed to low DOC content in the sediment.

  4. Mercury bioaccumulation in the food web of Three Gorges Reservoir (China): Tempo-spatial patterns and effect of reservoir management

    International Nuclear Information System (INIS)

    Tempo-spatial patterns of mercury bioaccumulation and tropho-dynamics, and the potential for a reservoir effect were evaluated in the Three Gorges Reservoir (TGR, China) from 2011 to 2012, using total mercury concentrations (THg) and stable isotopes (δ13C and δ15N) of food web components (seston, aquatic invertebrates and fish). Hg concentrations in aquatic invertebrates and fish indicated a significant temporal trend associated with regular seasonal water-level manipulation. This includes water level lowering to allow for storage of water during the wet season (summer); a decrease of water levels from September to June providing a setting for flood storage. Hg concentrations in organisms were the highest after flooding. Higher Hg concentrations in fish were observed at the location farthest from the dam. Hg concentrations in water and sediment were correlated. Compared with the reservoirs of United States and Canada, TGR had lower trophic magnification factors (0.046–0.066), that are explained primarily by organic carbon concentrations in sediment, and the effect of “growth dilution”. Based on comparison before and after the impoundment of TGR, THg concentration in biota did not display an obvious long-term reservoir effect due to (i) short time since inundation, (ii) regular water discharge associated with water-level regulation, and/or (iii) low organic matter content in the sediment. - Highlights: • Hg concentrations were measured in biota of the main stem of 3 Gorges Reservoir. • Fish Hg concentration post-flood period > pre-flood period > flood period. • Fish Hg concentrations were the highest farthest from the dam. • THg in fish 2 years after inundation were the same as before impoundment. • Low biomagnification was ascribed to low DOC content in the sediment

  5. Assessment of potential aquatic herbicide impacts to California aquatic ecosystems.

    Science.gov (United States)

    Siemering, Geoffrey S; Hayworth, Jennifer D; Greenfield, Ben K

    2008-10-01

    A series of legal decisions culminated in 2002 with the California State Water Resources Control Board funding the San Francisco Estuary Institute to develop and implement a 3-year monitoring program to determine the potential environmental impacts of aquatic herbicide applications. The monitoring program was intended to investigate the behavior of all aquatic pesticides in use in California, to determine potential impacts in a wide range of water-body types receiving applications, and to help regulators determine where to direct future resources. A tiered monitoring approach was developed to achieve a balance between program goals and what was practically achievable within the project time and budget constraints. Water, sediment, and biota were collected under "worst-case" scenarios in close association with herbicide applications. Applications of acrolein, copper sulfate, chelated copper, diquat dibromide, glyphosate, fluridone, triclopyr, and 2,4-D were monitored. A range of chemical analyses, toxicity tests, and bioassessments were conducted. At each site, risk quotients were calculated to determine potential impacts. For sediment-partitioning herbicides, sediment quality triad analysis was performed. Worst-case scenario monitoring and special studies showed limited short-term and no long-term toxicity directly attributable to aquatic herbicide applications. Risk quotient calculations called for additional risk characterizations; these included limited assessments for glyphosate and fluridone and more extensive risk assessments for diquat dibromide, chelated copper products, and copper sulfate. Use of surfactants in conjunction with aquatic herbicides was positively associated with greater ecosystem impacts. Results therefore warrant full risk characterization for all adjuvant compounds. PMID:18293029

  6. Aquatic pathway 1

    International Nuclear Information System (INIS)

    This first part of the study discusses problems of exposure due to the emission of radioactive substances into the environment via the water pathway. Discussion is started with a paper on the fundamentals of calculation and another paper on the results of preliminary radiological model calculations. The colloquium will assess the present state of knowledge, helps to find an agreement between divergent opinions and determine open questions and possible solutions. Ten main problems have been raised, most of which pertain to site conditions. They are trated as sub-investigations by individual participants or working groups. The findings will be discussed in further colloquia. (orig.)

  7. Mercury in mercury(II)-spiked soils is highly susceptible to plant bioaccumulation.

    Science.gov (United States)

    Hlodák, Michal; Urík, Martin; Matúš, Peter; Kořenková, Lucia

    2016-01-01

    Heavy metal phytotoxicity assessments usually use soluble metal compounds in spiked soils to evaluate metal bioaccumulation, growth inhibition and adverse effects on physiological parameters. However, exampling mercury phytotoxicity for barley (Hordeum vulgare) this paper highlights unsuitability of this experimental approach. Mercury(II) in spiked soils is extremely bioavailable, and there experimentally determined bioaccumulation is significantly higher compared to reported mercury bioaccumulation efficiency from soils collected from mercury-polluted areas. Our results indicate this is not affected by soil sorption capacity, thus soil ageing and formation of more stable mercuric complexes with soil fractions is necessary for reasonable metal phytotoxicity assessments.

  8. Strong linkages between DOM optical properties and main clades of aquatic bacteria

    DEFF Research Database (Denmark)

    Amaral, Valentina; Graeber, Daniel; Calliari, Danilo;

    2016-01-01

    Despite considerable research on the linkages between dissolved organic matter (DOM) and bacteria, it is not yet clear how the abundance of the main aquatic clades relates to DOM composition in natural aquatic systems. We evaluated this relation using PARAFAC modeling of excitation–emission fluor...

  9. Proposed Release Guides to Protect Aquatic Biota

    Energy Technology Data Exchange (ETDEWEB)

    Marter, W.L.

    2001-03-28

    At the request of South Carolina Department of Health and Environmental Control (SCDHEC) and the Department of Energy (DOE), the Savannah River Laboratory was assigned the task of developing the release guides to protect aquatic biota. A review of aquatic radioecology literature by two leading experts in the field of radioecology concludes that exposure of aquatic biota at one rad per day or less will not produce detectable deleterious effects on aquatic organisms. On the basis of this report, DOE recommends the use of one rad per day as an interim dose standard to protect aquatic biota.

  10. Optimization of methodology by X-ray fluorescence for the metals determination in aquatic plants of the high course of the Lerma river; Optimizacion de la metodologia por fluorescencia de rayos X para la determinacion de metales en plantas acuaticas del curso alto del Rio Lerma

    Energy Technology Data Exchange (ETDEWEB)

    Albino P, E.

    2015-07-01

    The high course of the Lerma river has a pollution problem in its hydrological system due to discharges of urban wastewater and industrial areas; the pollutants that affect the hydrological system are metals, which are absorbed by living organisms and probably incorporated into the food chain. For this reason in this work the technique of X-ray fluorescence total reflection was applied in six species of aquatic plants that grow in the high course of the Lerma river: Arroyo Mezapa (Eichhornia crassipes, Juncus efusus, Hydrocotyle, Schoenoplectus validus) Ameyalco river (Lemna gibba) and Atarasquillo river (Berula erecta) in order to evaluate the metals concentration (Cr, Mn, Fe, Ni, Cu, Zn and Pb) as well as the translocation factor and bioaccumulation factor for each aquatic species. According to the results, was observed that the highest concentration of metals is located in the deeper parts; metals which present a significant concentration are Mn and Fe in the six species of aquatic plants. According to the translocation factor the species having a higher translocation of metals are: Juncus efusus in Mn (1.19 mg/L) and Zn (1.31 mg/L), Hydrocotyle (1.14 mg/L), the species Eichhornia crassipes not show translocation. For bioaccumulation factor, was observed that the most bioaccumulation of metals is found in the soluble fraction of the six species of aquatic plants, especially Fe followed of Cu and Zn. Also was considered that the Berula erecta plant had a higher bioaccumulation of metals such as Cr, Mn, Fe, Cu and Zn so it can be considered as a hyper-accumulating species of these elements. With the results can be considered that the technique of X-ray fluorescence total reflection is 95% reliable to determine the concentration of metals within the structures of the aquatic plants used for this study. (Author)

  11. CHROMIUM BIOACCUMULATION FROM COMPOSTS AND VERMICOMPOSTS BASED ON TANNERY SLUDGES

    Directory of Open Access Journals (Sweden)

    Krzysztof GONDEK

    2008-07-01

    Full Text Available Storage of waste substances is not indifferent to ecological equilibrium in the environment therefore should not be the ultimate way to limit waste arduousness. Therefore, the conducted investigations aimed to determine the effect of tannery composts and vermicomposts loaded with chromium on this element bioaccumulation in earthworm bodies and biomass of selected plants. Chromium in composts and vermicomposts based on tannery sludges occurred in small quantities and easily soluble compounds. Chromium concentrations in redworm biomass points to this metal accumulation in Eisenia fetida body tissues. This element content in redworm biomass was signifi cantly positively correlated with its content in composts. Chromium content in plants was diversifi ed and on treatments was generally smaller than on mineral treatment or farmyard manure. Chromium absorbed by plants was stored mainly in the root systems, and over the norm content of this element found in vermicomposts did not cause its excessive accumulation in plant biomass.

  12. Bioaccumulation of heavy metals by fimbrial designer adhesins

    DEFF Research Database (Denmark)

    Schembri, Mark; Kjærgaard, Kristian; Klemm, Per

    1999-01-01

    Naturally occurring adhesins bind to specific molecular targets in a lock-and-key fashion due to the composition of the binding domain of the adhesin. By introduction of random peptide libraries in a suitable surface exposed carrier protein it is possible to create and select designer adhesins wi...... for the bioaccumulation of heavy metals from the environment. (C) 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved........ By serial selection and enrichment procedures specific sequences were identified which conferred the ability on recombinant cells to adhere to various metal oxides (PbO2, CoO, MnO2, Cr2O3 ) The properties inherent in these sequences permitted the distinct recognition of metals to varying degrees, indicating...

  13. Effects of ionizing radiation on aquatic organisms and ecosystems

    International Nuclear Information System (INIS)

    A panel of experts in November 1971 specifically considered the effects of ionizing radiation on aquatic organisms and ecosystems and formulated detailed suggestions for research in the area. A further panel meeting took place in April 1974. The results of the work are presented in this report which is divided into 3 chapters in the first chapter the concentrations of natural and artificial radionuclides in aquatic environments and the radiation dose rates received by aquatic organisms are discussed. In particular, simple dosimetry models for phytoplankton, zooplankton, mollusca, crustacea and fish are presented which permit the estimation of the dose rates from incorporated radionuclides and from radionuclides in the external environment. In the second chapter the somatic and genetic effects of ionizing radiation on aquatic organisms are reviewed. Somatic effects are discussed separately as effects due to short-term (acute) exposure to near-lethal doses of radiation. Great attention is paid to the effects due to long-term (chronic) exposure at lower doses rates. Consideration is given to behaviour, repair mechanisms and metabolic stimulation after exposure, and also the influence of environmental factors on radiation effects. In the third chapter the potential effects of low-level irradiation on aquatic populations are considered. First, the possible consequences of somatic effects on egg and larval mortality, stock-recruitment, fecundity and ecosystem stability are discussed. Subsequently, the assessment of genetic effects as they relate to population genetics and increased mutation rates are considered

  14. 定量评估水生资源及生态系统的EWE营养模型研究%Study on EWE Nutrition Model for the Quantitative Assessment of Aquatic Resources and Ecosystem

    Institute of Scientific and Technical Information of China (English)

    欧阳力剑; 胥献宇; 胡思玉; 刘文

    2011-01-01

    According to environmental data. Ecopath with Ecosim (EWE) can quantitatively describe the energy flow in the produolion and consumption of function components of system by using trophodynamics, and accurately assess the biomass and stable state of aquatic ecosys tem. In the paper, the basic principle and parameter) of EWE model were introduced firstly, then the relationship between Q/B (the important parameter of EWE model) and basic life indies of fish was discussed, and the current study and typical results of EWE model were analyzed finally.%基于环境调查数据,EWE生态营养通道模型利用营养动力学原理,定量描述系统中各功能成分生产和消耗的能量流动,能较为准确地评估稳定状态下水域生态系统组份的生物量及其系统稳定状态:首先概括了EWE模型的基本原理和基本参数,然后探讨了EWE重要参数Q/B与鱼类基本生命指标之间的关系,最后分析了EWE模型的研究现状及典型研究成果.

  15. Enantioseletive bioaccumulation of tebuconazole in earthworm Eisenia fetida

    Institute of Scientific and Technical Information of China (English)

    Dingyi Yu; Jianzhong Li; Yanfeng Zhang; Huili Wang; Baoyuan Guo; Lin Zheng

    2012-01-01

    Methods of extraction and determination of tebuconazole enantiomers in earthworm (Eisenia fetida) were developed by capillary electrophoresis (CE) and high performance liquid chromatography (HPLC).Both CE and HPLC have excellent resolution and recovery.The linearity ranges were 2.9-102.4 mg/kg and 3.0-99.6 mg/kg for (+)-R-tebuconazole and (-)-S-tebuconazole respectively in CE,and from 0.56 to 1000 mg/kg for both enantiomers in HPLC.Enantioselective bioaccumulation in earthworms from soil was investigated under laboratory condition at concentrations of 10 and 50 mg/kg dw in soil.The uptake kinetics of (+)-R-tebuconazole fitted the firstorder kinetics well with r2 0.97 and 0.94 under 10 and 50 mg/kg dw exposure condition,respectively,while (-)-S-tebueonazole with r2 0.75 and 0.22 did not show the same.Bioaccumulation of tebuconazole in earthworm tissues was enantioselective with a preferential accumulation of (+)-R-tebuconazole.The (+)-R-tebuconazole might also have biomagnifying effect potential in earthworm food chain with biota-sediment accumulation factor (BSAF) of 1.64 kg OC/kg lip in 10 mg/kg dw exposure group and 2.61 kg OC/kg lip in 50 mg/kg dw exposure group from soil to earthworm after 36 days.Although (-)-S-tebuconazole shares the same physicochemical properties with (+)-R-tebuconazole,it did not biomagnify.BSAFs of (-)-S-tebuconazole were 0.50 kg OC/kg lip (10 mg/kg dw tebuconazole exposure) and 0.28 kg OC/kg lip (50 mg/kg dw tebuconazole exposure) after 36 days,which was possibly owing to biotransformation or metabolism in earthworm tissues.

  16. A Study on the Fluid Mechanics Performance of Aquatics Equipment

    Directory of Open Access Journals (Sweden)

    Jiao Jian

    2015-01-01

    Based on the theoretical foundation of fluid mechanics performance, this paper carries out an analysis on mechanical characteristics of aquatic sports. First, basic features of windsurfing are studied in this paper. Performance of windsurfing changes with its parameters, requiring a lot for windsurfers. It can be known from variance analysis that the best performance of NP plate and a relatively small resistance should be the direction of sail-board design. Meanwhile, by building up a mathematical model with fuzzy comprehensive evaluation and correlation analysis, it can be also found that the fluid resistance characteristic is a key factor that influences the performance of windsurfers. Besides, this paper also takes into account external factors, including the influences of regional difference on aquatic events. Different regions with various geographical conditions have different influences on aquatic events.

  17. Optimizing Stream Water Mercury Sampling for Calculation of Fish Bioaccumulation Factors

    Science.gov (United States)

    Mercury (Hg) bioaccumulation factors (BAFs) for game fishes are widely employed for monitoring, assessment, and regulatory purposes. Mercury BAFs are calculated as the fish Hg concentration (Hgfish) divided by the water Hg concentration (Hgwater) and, consequently, are sensitive ...

  18. Optimizing the use of rainbow trout hepatocytes for bioaccumulation assessments with fish

    Science.gov (United States)

    Measured rates of biotransformation by cryopreserved trout hepatocytes can be extrapolated to the whole animal as a means of predicting metabolism impacts on chemical bioaccumulation. Future use of these methods within a regulatory context requires, however, that they be standar...

  19. Molecular effects and bioaccumulation of levonorgestrel in the non-target organism Dreissena polymorpha

    DEFF Research Database (Denmark)

    Contardo-Jara, V.; Lorenz, Claudia; Pflugmacher, S.;

    2011-01-01

    Bioaccumulation and effects of the contraceptive hormone levonorgestrel were examined in the nontarget organism Dreissena polymorpha. Molecular biomarkers of biotransformation, elimination, antioxidant defence and protein damage were analyzed after exposure to increasing concentrations of levonor...

  20. DISTRIBUTION OF TOTAL AND METHYLMERCURY IN DIFFERENT ECOSYSTEM COMPARTMENTS IN THE EVERGLADES: IMPLICATIONS FOR MERCURY BIOACCUMULATION

    Science.gov (United States)

    Mercury (Hg) species distribution patterns among ecosystem compartments in the Everglades were analyzed at the landscape level in order to explore the implications of Hg distribution for Hg bioaccumulation, and to investigate major biogeochemical processes that are pertinent to t...

  1. Mathematical modeling of pollutant and radionuclide transformation in aquatic ecosystems results of elaboration and verification for the chain of industrial reservoirs on the Techa River

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A.B.; Mokrov, Y.G.; Glagolenko, Y.V.; Drozhko, E.G. [Mayak, Ozersk (Russian Federation); Khodakovsky, I.L.; Leonov, A.V. [Russian Academy of Sciences, Moscow (Russian Federation)

    1995-12-31

    The modern radioecological situation around the oldest radiochemical plant, Mayak, in South Ural (Russia) is indicated by the storage of 300 million to tons of low level radioactive waste in the Techa`s reservoir chain (TRC). Future approaches for TRC restoration may be evaluated using corresponding mathematical models. The mathematical modeling complex, KASKAD, was developed at Mayak and is intended for reservoir radioecological state forecasting and alternative remediation approaches evaluation. The paper describes this model.

  2. Mathematical modeling of pollutant and radionuclide transformation in aquatic ecosystems results of elaboration and verification for the chain of industrial reservoirs on the Techa River

    International Nuclear Information System (INIS)

    The modern radioecological situation around the oldest radiochemical plant, Mayak, in South Ural (Russia) is indicated by the storage of 300 million to tons of low level radioactive waste in the Techa's reservoir chain (TRC). Future approaches for TRC restoration may be evaluated using corresponding mathematical models. The mathematical modeling complex, KASKAD, was developed at Mayak and is intended for reservoir radioecological state forecasting and alternative remediation approaches evaluation. The paper describes this model

  3. Procedures for Collecting and Processing Aquatic Invertebrates and Fish for Analysis of Mercury as Part of the National Water-Quality Assessment Program

    Science.gov (United States)

    Scudder, Barbara C.; Chasar, Lia C.; DeWeese, L. Rod; Brigham, Mark E.; Wentz, Dennis A.; Brumbaugh, William G.

    2008-01-01

    Mercury studies conducted as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program have included nationwide reconnaissance samplings of hundreds of stream sites, as well as detailed, process-oriented research at selected sites. These reconnaissance and detailed studies are intended to provide a better understanding of methylmercury bioaccumulation in stream ecosystems over a range of environmental settings. This publication describes trace-element-clean techniques used for collection and processing of aquatic invertebrates and fish to be analyzed for total mercury, methylmercury, and stable isotopes as part of NAWQA studies.

  4. 应用Abraham方程研究有机污染物对七种水生生物的毒性∗%Study on the toxicity of organic pollutants to seven aquatic organisms based on Abraham model

    Institute of Scientific and Technical Information of China (English)

    于洋; 王晓红; 闻洋; 赵元慧

    2015-01-01

    The toxicities of 141 organic pollutants to seven aquatic organisms ( Vibrio fischeri, River bacteria, Scenedesmus obliguue, Daphnia magna, Cyprinuscarpio, Pimephalespromelas, Poeciliareticulata) were analyzed. A linear relationship between the toxicity data of non⁃polar or polar narcotics and hydrophobicity (lgKow) was established for the seven species, respectively. This relationship was interpretated based on the theoretical consideration. Meanwhile, quantitative structure⁃activity relationship ( QSAR) studies were performed between the toxicities of seven aquatic organisms and Abraham descriptors. The mechanisms of action to seven species were analyzed theoretically based on Abraham descriptors and model coefficients. The principal component analysis carried out on the regression coefficients of Abraham models shows that there are interspecies similarities and differences between the species. In the same time, the interspecies correlation of organic pollutants to seven aquatic organisms was analyzed. The results show that there are good interspecies corrections between fish species, marine bacterium and fish or daphnia magna and fish. It is suggested that some compounds shared the same toxic mechanism of action between the species. However , poor interspecies relationships found between toxicities to algae and daphnia magna or fish suggested that compounds have different toxic mechanism of action between these species.%通过研究141种对7种水生生物(发光菌、江水细菌、绿藻、大型溞、鲤鱼、黑头呆鱼,古比鱼)的毒性,建立了非极性麻醉型和极性麻醉型有机物的毒性与辛醇/水分配系数的对数lgKow的相关性,并对该相关性进行了理论解释。同时,建立了Abraham参数与7种水生生物毒性的预测模型,根据Abraham参数和预测模型的系数,对有机污染物与生物毒性作用机理进行了理论分析。在此基础上,对Abraham毒性模型回归系数进行主

  5. Effects of storage on sediment toxicity, bioaccumulation potential, and chemistry. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tatem, H.E.; Brandon, D.L.; Lee, C.R.; Jarvis, A.S.; Rhett, R.G.

    1991-01-01

    Current guidance on storage of sediments for bioassay/bioaccumulation tests requires that samples be held at 4 C and used within 2 weeks of collection. The objective of this study was to determine the effects of sediment storage for 40 weeks on sediment toxicity, bioaccumulation potential, and chemical analyses. Toxicity and bioaccumulation tests were conducted five times during 40 weeks of storage. Chemical analyses were performed three times during this period. The data indicate that sediments can be held for longer than 2 to 4 weeks, in many cases, without significant effect on test results. However, results of the study also show that tests performed at different times can produce different results. This study showed that a sediment that was toxic to mysids remained toxic during 16 weeks of sediment storage. Two sediments that were toxic initially continued to show significant toxicity after 8 and 16 weeks of sediment storage. One sediment, not toxic initially or at 4 weeks, changed during storage, becoming significantly toxic compared to the Atlantic Ocean (Ref) sediment. The bioaccumulation results showed that certain sediment contaminants (lead, mercury, polychlorinated biphenyls, and some polycyclic aromatic hydrocarbons, PAHs), generally do not reveal a statistical change in bioaccumulation, relative to Ref animals, during 16 weeks of sediment storage. Other PAHs, including phenanthrene, anthracene, benzo (a) anthracene, and chrysene, did change in bioaccumulation potential during storage.

  6. Bioaccumulation and depuration of chromium in the selected organs and whole body tissues of freshwater fish Cirrhinus mrigala individually and in binary solutions with nickel

    Institute of Scientific and Technical Information of China (English)

    PL. RM. Palaniappan; S. Karthikeyan

    2009-01-01

    Contamination of aquatic ecosystems with heavy metals has been receiving increased worldwide attention due to their harmful effects on human health and other organisms in the environment.Most of the studies dealing with toxic effects of metals deal with single metal species, while the aquatic organisms are typically exposed to mixtures of metals.Hence, in order to provide data supporting the usefulness of freshwater fish as indicators of heavy metal pollution, it has been proposed in the present study to investigate the bioaccumulation and depuration of chromium in the selected organs of freshwater fingerlings Cirrhinus mrigala, individually and in binary solutions with nickel.The results show that the kidney is a target organ for chromium accumulation, which implies that it is also the "critical" organ for toxic symptoms.The results further show that accumulation of nickel in all the tissues of C.mrigala is higher than that of chromium.In addition, the metal accumulations of the binary mixtures of chromium and nickel are substantially higher than those of the individual metals, indicating synergistic interactions between the two metals.Theoretically the simplest explanation for an additive joint action of toxicants in a mixture is that they act in a qualitatively similar way.The observed data suggest that C.mrigala could be suitable monitoring organisms to study the bioavailability of water-bound metals in freshwater habitats.

  7. Invertebrates in stormwater wet detention ponds - Sediment accumulation and bioaccumulation of heavy metals have no effect on biodiversity and community structure.

    Science.gov (United States)

    Stephansen, Diana Agnete; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Pedersen, Morten Lauge; Vollertsen, Jes

    2016-10-01

    The invertebrate diversity in nine stormwater wet detention ponds (SWDP) was compared with the diversity in eleven small shallow lakes in the western part of Denmark. The SWDPs and lakes were chosen to reflect as large a gradient of pollutant loads and urbanization as possible. The invertebrates as well as the bottom sediments of the ponds and shallow lakes were analyzed for copper, iron, zinc, cadmium, chromium, lead, aluminum, nickel, arsenic and the potentially limiting nutrient, phosphorus. The Principal Component Analysis showed that invertebrates in SWDPs and lakes differed with respect to bioaccumulation of these elements, as did the sediments, albeit to a lesser degree. However, the Detrended Correspondence Analysis and the TWINSPAN showed that the invertebrate populations of the ponds and lakes could not be distinguished, with the possible exception of highway ponds presenting a distinct sub-group of wet detention ponds. The SWDPs and shallow lakes studied seemed to constitute aquatic ecosystems of similar taxon richness and composition as did the 11 small and shallow lakes. This indicates that SWDPs, originally constructed for treatment and flood protection purposes, become aquatic environments which play a local role for biodiversity similar to that of natural small and shallow lakes. PMID:27302374

  8. FABM-PCLake - linking aquatic ecology with hydrodynamics

    Science.gov (United States)

    Hu, Fenjuan; Bolding, Karsten; Bruggeman, Jorn; Jeppesen, Erik; Flindt, Morgens R.; van Gerven, Luuk; Janse, Jan H.; Janssen, Annette B. G.; Kuiper, Jan J.; Mooij, Wolf M.; Trolle, Dennis

    2016-07-01

    This study presents FABM-PCLake, a redesigned structure of the PCLake aquatic ecosystem model, which we implemented in the Framework for Aquatic Biogeochemical Models (FABM). In contrast to the original model, which was designed for temperate, fully mixed freshwater lakes, the new FABM-PCLake represents an integrated aquatic ecosystem model that can be linked with different hydrodynamic models and allows simulations of hydrodynamic and biogeochemical processes for zero-dimensional, one-dimensional as well as three-dimensional environments. FABM-PCLake describes interactions between multiple trophic levels, including piscivorous, zooplanktivorous and benthivorous fish, zooplankton, zoobenthos, three groups of phytoplankton and rooted macrophytes. The model also accounts for oxygen dynamics and nutrient cycling for nitrogen, phosphorus and silicon, both within the pelagic and benthic domains. FABM-PCLake includes a two-way communication between the biogeochemical processes and the physics, where some biogeochemical state variables (e.g., phytoplankton) influence light attenuation and thereby the spatial and temporal distributions of light and heat. At the same time, the physical environment, including water currents, light and temperature influence a wide range of biogeochemical processes. The model enables studies on ecosystem dynamics in physically heterogeneous environments (e.g., stratifying water bodies, and water bodies with horizontal gradients in physical and biogeochemical properties), and through FABM also enables data assimilation and multi-model ensemble simulations. Examples of potential new model applications include climate change impact studies and environmental impact assessment scenarios for temperate, sub-tropical and tropical lakes and reservoirs.

  9. NorWeST: A Regional Stream Temperature Model for High-Resolution Aquatic Vulnerability Assessments in the Northwest U.S

    Science.gov (United States)

    Wenger, S.; Isaak, D.; Dunham, J.; Hostetler, S.; Kershner, J.; Peterson, D.; Peterson, E.; Luce, C.; Roper, B.; Ver Hoef, J.; Nagel, D.; Hockman-Wert, D.; Horan, D.; Chandler, G.; Parkes, S.; Wollrab, S.

    2012-12-01

    The unknown consequences of climate change on the Earth's biodiversity create significant challenges for natural resource conservation. Effective resource stewardship will require development of datasets and models for downscaling climate change effects on organisms to scales relevant to species management. Through a project funded in part by Great Northern Landscape Conservation Cooperative, we assembled NorWeST, a stream temperature database for the Northwest U.S. consisting of >45,000 summers of measurement at >15,000 unique stream sites collected by dozens of resource agencies. These data are being used to develop a stream temperature model that makes predictions at 1 km resolution for 350,000 km of streams in the region. The stream temperature model is then forced by the USGS RegCM3 dynamically downscaled regional climate model to reconstruct historical climate stream temperatures and make future projections. Finally, the stream temperature model predictions are being integrated into several related projects that include: 1) biological vulnerability assessments, 2) defining species' thermal niches, 3) improved bioclimatic models, 4) decision support tools, and 5) temperature and biological monitoring efforts. We present preliminary results from pilot projects for vulnerability assessments and thermal niche classifications for imperiled fish species in the Northwest U.S.

  10. Improving aquatic warbler population assessments by accounting for imperfect detection.

    Science.gov (United States)

    Oppel, Steffen; Marczakiewicz, Piotr; Lachmann, Lars; Grzywaczewski, Grzegorz

    2014-01-01

    Monitoring programs designed to assess changes in population size over time need to account for imperfect detection and provide estimates of precision around annual abundance estimates. Especially for species dependent on conservation management, robust monitoring is essential to evaluate the effectiveness of management. Many bird species of temperate grasslands depend on specific conservation management to maintain suitable breeding habitat. One such species is the Aquatic Warbler (Acrocephalus paludicola), which breeds in open fen mires in Central Europe. Aquatic Warbler populations have so far been assessed using a complete survey that aims to enumerate all singing males over a large area. Because this approach provides no estimate of precision and does not account for observation error, detecting moderate population changes is challenging. From 2011 to 2013 we trialled a new line transect sampling monitoring design in the Biebrza valley, Poland, to estimate abundance of singing male Aquatic Warblers. We surveyed Aquatic Warblers repeatedly along 50 randomly placed 1-km transects, and used binomial mixture models to estimate abundances per transect. The repeated line transect sampling required 150 observer days, and thus less effort than the traditional 'full count' approach (175 observer days). Aquatic Warbler abundance was highest at intermediate water levels, and detection probability varied between years and was influenced by vegetation height. A power analysis indicated that our line transect sampling design had a power of 68% to detect a 20% population change over 10 years, whereas raw count data had a 9% power to detect the same trend. Thus, by accounting for imperfect detection we increased the power to detect population changes. We recommend to adopt the repeated line transect sampling approach for monitoring Aquatic Warblers in Poland and in other important breeding areas to monitor changes in population size and the effects of habitat management.

  11. Improving aquatic warbler population assessments by accounting for imperfect detection.

    Directory of Open Access Journals (Sweden)

    Steffen Oppel

    Full Text Available Monitoring programs designed to assess changes in population size over time need to account for imperfect detection and provide estimates of precision around annual abundance estimates. Especially for species dependent on conservation management, robust monitoring is essential to evaluate the effectiveness of management. Many bird species of temperate grasslands depend on specific conservation management to maintain suitable breeding habitat. One such species is the Aquatic Warbler (Acrocephalus paludicola, which breeds in open fen mires in Central Europe. Aquatic Warbler populations have so far been assessed using a complete survey that aims to enumerate all singing males over a large area. Because this approach provides no estimate of precision and does not account for observation error, detecting moderate population changes is challenging. From 2011 to 2013 we trialled a new line transect sampling monitoring design in the Biebrza valley, Poland, to estimate abundance of singing male Aquatic Warblers. We surveyed Aquatic Warblers repeatedly along 50 randomly placed 1-km transects, and used binomial mixture models to estimate abundances per transect. The repeated line transect sampling required 150 observer days, and thus less effort than the traditional 'full count' approach (175 observer days. Aquatic Warbler abundance was highest at intermediate water levels, and detection probability varied between years and was influenced by vegetation height. A power analysis indicated that our line transect sampling design had a power of 68% to detect a 20% population change over 10 years, whereas raw count data had a 9% power to detect the same trend. Thus, by accounting for imperfect detection we increased the power to detect population changes. We recommend to adopt the repeated line transect sampling approach for monitoring Aquatic Warblers in Poland and in other important breeding areas to monitor changes in population size and the effects of

  12. Application of Bayesian regularized BP neural network model for analysis of aquatic ecological data--A case study of chlorophyll-a prediction in Nanzui water area of Dongting Lake

    Institute of Scientific and Technical Information of China (English)

    XU Min; ZENG Guang-ming; XU Xin-yi; HUANG Guo-he; SUN Wei; JIANG Xiao-yun

    2005-01-01

    Bayesian regularized BP neural network(BRBPNN) technique was applied in the chlorophyll-a prediction of Nanzui water area in Dongting Lake. Through BP network interpolation method, the input and output samples of the network were obtained. After the selection of input variables using stepwise/multiple linear regression method in SPSS 11.0 software, the BRBPNN model was established between chlorophyll-a and environmental parameters, biological parameters. The achieved optimal network structure was 3-11-1 with the correlation coefficients and the mean square errors for the training set and the test set as 0.999 and 0.00078426, 0.981 and 0.0216 respectively. The sum of square weights between each input neuron and the hidden layer of optimal BRBPNN models of different structures indicated that the effect of individual input parameter on chlorophyll-a declined in the order of alga amount > secchi disc depth(SD) > electrical conductivity (EC) . Additionally, it also demonstrated that the contributions of these three factors were the maximal for the change of chlorophyll-a concentration, total phosphorus(TP) and total nitrogen(TN) were the minimal. All the results showed that BRBPNN model was capable of automated regularization parameter selection and thus it may ensure the excellent generation ability and robustness. Thus, this study laid the foundation for the application of BRBPNN model in the analysis of aquatic ecological data(chlorophyll-a prediction) and the explanation about the effective eutrophication treatment measures for Nanzui water area in Dongting Lake.

  13. Marine envenomations and aquatic dermatology.

    Science.gov (United States)

    Soppe, G G

    1989-08-01

    Jellyfish stings are usually mild except those caused by species in the South Pacific. The box jellyfish can produce a severe cardiorespiratory insult. The sting of the Portuguese man-of-war is more potent than that of the common jellyfish. The Indo-Pacific area is the source of the most venomous bony fish. Many injuries can be avoided by wearing shoes when walking in shallow water or tide pools. Aquatic-related skin infections may involve unusual organisms. Swimmer's itch, a disease of freshwater bathing, is caused by cercariae. Seabather's eruption produces a rash in swimsuit-covered areas; the etiology is not clear. PMID:2569260

  14. Phytoremediation Potential of Aquatic Macrophyte, Azolla

    OpenAIRE

    Sood, Anjuli; Uniyal, Perm L.; Prasanna, Radha; Ahluwalia, Amrik S.

    2011-01-01

    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 us...

  15. Toxicity assessment of boron (B) by Lemna minor L. and Lemna gibba L. and their possible use as model plants for ecological risk assessment of aquatic ecosystems with boron pollution.

    Science.gov (United States)

    Gür, Nurcan; Türker, Onur Can; Böcük, Harun

    2016-08-01

    As many of the metalloid-based pollutants, the boron (B) toxicity issues have aroused more and more global attentions, especially concerning drinking water sources which flow through boron-rich areas. Therefore, feasible and innovative approaches are required in order to assess B toxicity in aquatic ecosystems. In this study, the toxic effects of B on Lemna minor L. and Lemna gibba L. were investigated using various endpoints including number of fronds, growth rates, dry biomass and antioxidants enzymatic activities. Lemna species were exposed to B concentrations of 2 (control), 4, 8, 16, 32, 64 and 128 mg L(-1) for a test period of 7 days. The results demonstrated that plant growth was significantly reduced when the B concentration reached 16 mg L(-1). Furthermore, our results also concluded that among the antioxidative enzymes, SOD, APX and GPX can serve as important biomarkers for B-rich environment. The present results suggested that L. minor and L. gibba are very useful model plants for phytoremediation of low-B contaminated wastewater and they are also suitable options for B biomonitoring due to high phototoxic sensitivity against B. In this respect, the scientific insight of the present study is to fill the gaps in the research about the use of L. minor and L. gibba in ecotoxicological research associated with B toxicity. PMID:27192627

  16. Radioactivity in the Canadian aquatic environment

    International Nuclear Information System (INIS)

    Sources of radionuclides arising from natural anthropogenic processes as well as technologically enhanced natural radiation are discussed. Transport, distribution and behaviour of these radionuclides in aquatic systems are influenced by physical, chemical, biological and geological processes and conditions in freshwater and marine environments. Dosimetry of aquatic organisms, as well as various methods of measuring dose rate are presented. Effects of ionizing radiation (acute and chronic exposure) on aquatic organisms, populations and ecosystems are reviewed. This review covers the entire spectrum of the aquatic environment. Results of many studies are summarized. 300+ refs

  17. Actinide elements in aquatic and terrestrial environments

    International Nuclear Information System (INIS)

    Progress is reported in terrestrial ecology studies with regard to plutonium in biota from the White Oak Creek forest; comparative distribution of plutonium in two forest ecosystems; an ecosystem model of plutonium dynamics; actinide element metabolism in cotton rats; and crayfish studies. Progress is reported in aquatic studies with regard to transuranics in surface waters, frogs, benthic algae, and invertebrates from pond 3513; and radioecology of transuranic elements in cotton rats bordering waste pond 3513. Progress is also reported in stability of trivalent plutonium in White Oak Lake water; chemistry of plutonium, americium, curium, and uranium in pond water; uranium, thorium, and plutonium in small mammals; and effect of soil pretreatment on the distribution of plutonium

  18. A Model-Based Prioritisation Exercise for the European Water Framework Directive

    Directory of Open Access Journals (Sweden)

    Paul Whitehouse

    2011-02-01

    Full Text Available A model-based prioritisation exercise has been carried out for the Water Framework Directive (WFD implementation. The approach considers two aspects: the hazard of a certain chemical and its exposure levels, and focuses on aquatic ecosystems, but also takes into account hazards due to secondary poisoning, bioaccumulation through the food chain and potential human health effects. A list provided by EU Member States, Stakeholders and Non-Governmental Organizations comprising 2,034 substances was evaluated according to hazard and exposure criteria. Then 78 substances classified as “of high concern” where analysed and ranked in terms of risk ratio (Predicted Environmental Concentration/Predicted No-Effect Concentration. This exercise has been complemented by a monitoring-based prioritization exercise using data provided by Member States. The proposed approach constitutes the first step in setting the basis for an open modular screening tool that could be used for the next prioritization exercises foreseen by the WFD.

  19. A model-based prioritisation exercise for the European water framework directive.

    Science.gov (United States)

    Daginnus, Klaus; Gottardo, Stefania; Payá-Pérez, Ana; Whitehouse, Paul; Wilkinson, Helen; Zaldívar, José-Manuel

    2011-02-01

    A model-based prioritisation exercise has been carried out for the Water Framework Directive (WFD) implementation. The approach considers two aspects: the hazard of a certain chemical and its exposure levels, and focuses on aquatic ecosystems, but also takes into account hazards due to secondary poisoning, bioaccumulation through the food chain and potential human health effects. A list provided by EU Member States, Stakeholders and Non-Governmental Organizations comprising 2,034 substances was evaluated according to hazard and exposure criteria. Then 78 substances classified as "of high concern" where analysed and ranked in terms of risk ratio (Predicted Environmental Concentration/Predicted No-Effect Concentration). This exercise has been complemented by a monitoring-based prioritization exercise using data provided by Member States. The proposed approach constitutes the first step in setting the basis for an open modular screening tool that could be used for the next prioritization exercises foreseen by the WFD. PMID:21556195

  20. The effect of pH on chronic aquatic nickel toxicity is dependent on the pH itself: Extending the chronic nickel bioavailability models.

    Science.gov (United States)

    Nys, Charlotte; Janssen, Colin R; Van Sprang, Patrick; De Schamphelaere, Karel A C

    2016-05-01

    The environmental quality standard for Ni in the European Commission's Water Framework Directive is bioavailability based. Although some of the available chronic Ni bioavailability models are validated only for pH ≤ 8.2, a considerable fraction of European surface waters has a pH > 8.2. Therefore, the authors investigated the effect of a change in pH from 8.2 to 8.7 on chronic Ni toxicity in 3 invertebrate (Daphnia magna, Lymnaea stagnalis, and Brachionus calyciflorus) and 2 plant species (Pseudokirchneriella subcapitata and Lemna minor). Nickel toxicity was almost always significantly higher at pH 8.7 than at pH 8.2. To test whether the existing chronic Ni bioavailability models developed for pH ≤ 8.2 can be used at higher pH levels, Ni toxicity at pH 8.7 was predicted based on Ni toxicity observed at pH 8.2. This resulted in a consistent underestimation of toxicity. The results suggest that the effect of pH on Ni(2+) toxicity is dependent on the pH itself: the slope of the pH effect is steeper above than below pH 8.2 for species for which a species-specific bioavailability model exists. Therefore, the existing chronic Ni bioavailability models were modified to allow predictions of chronic Ni toxicity to invertebrates and plants in the pH range of 8.2 to 8.7 by applying a pH slope (SpH ) dependent on the pH of the target water. These modified Ni bioavailability models resulted in more accurate predictions of Ni toxicity to all 5 species (within 2-fold error), without the bias observed using the bioavailability models developed for pH ≤ 8.2. The results of the present study can decrease the uncertainty in implementing the bioavailability-based environmental quality standard under the Water Framework Directive for high-pH regions in Europe. PMID:26335781

  1. Uranium in aquatic sediments: Where are the guidelines?

    International Nuclear Information System (INIS)

    Full text: Water management at Ranger uranium mine in tropical northern Australia, involves the use of constructed biological wetland filters to passively reduce the concentrations of metals, including uranium and radium, in mine waters before their release off-site. The concentration reduction is achieved principally through partitioning of the metals from the water column into the sediments, resulting in contaminant build-up in the sediments. Environmental Requirements (ERs) for Ranger, enshrined in both Commonwealth and Northern Territory regulations, specify environmental objectives to be achieved during the life of the mine and following closure. While the ERs describe the broad objectives for rehabilitation, specific criteria are required to determine whether these objectives are met; including criteria for the rehabilitation of aquatic sediments contaminated by uptake of uranium and heavy metals. Routine monitoring of sediments in selected billabongs on and adjoining the Ranger Project Area and strategic environmental research has formed part of the regulatory framework governing the authority to operate for over 20 years. This included studies such as annual routine monitoring of metal concentrations, adsorption-desorption conditions, phase associations, transport mechanisms, release potential, bioaccumulation and bioconcentration etc. Building on this, performance-based monitoring of the sediments from on-site water bodies was undertaken to ascertain the spatial and temporal distribution of contaminants as a basis to determine ecological risks associated with the sediments which in turn underpins closure planning. Highlights of these studies are interpreted using an ecological risk assessment approach. Ideally interpretation of aquatic sediment contamination in Australia is guided by the national guidelines for water quality (ANZECC and ARMCANZ 2000) and a weighted multiple lines of evidence approach (Simpson et. al., 2005) whereby the chemistry of

  2. Application of a k- ɛ formulation to model the effect of submerged aquatic vegetation on turbulence induced by an oscillating grid

    Science.gov (United States)

    Casamitjana, Xavier; Pujol, Dolors; Colomer, Jordi; Serra, Teresa

    2012-02-01

    Oscillating-grid turbulence (OGT) in a homogeneous fluid has been widely investigated. In a recent paper Pujol et al. (2010) used an oscillating grid to mimic wind-generated turbulence. They quantified the vertical distribution of turbulent kinetic energy (TKE) above and within different types of vegetation, which were simulated by constructing two different canopies at the bottom of a water tank. The first canopy, made of PVC cylinders, was rigid and the second, made of nylon threads, was semi-rigid. We propose a k- ɛ turbulence model to simulate the results obtained in their paper. Two source terms (˜(TKE) 3/2) were added to a classical k- ɛ turbulence formulation to account for canopy dissipation. Results of the model show good agreement with experimental data.

  3. Biologically mediated transport of contaminants to aquatic systems.

    Science.gov (United States)

    Blais, Jules M; Macdonald, Robie W; Mackay, Donald; Webster, Eva; Harvey, Colin; Smol, John P

    2007-02-15

    The prevailing view is that long-range transport of semivolatile contaminants is primarily conducted by the physical system (e.g., winds, currents), and biological transport is typically ignored. Although this view may be correct in terms of bulk budgets and fluxes, it neglects the potential of animals to focus contaminants into foodwebs due to their behaviors and lifecycles. In particular, gregarious animals that biomagnify and bioaccumulate certain contaminants and then migrate and congregate can become the predominant pathway for contaminants in many circumstances. Fish and birds provide prominent examples for such behavior. This review examines the potential for biovector transport to expose populations to contaminants. In addition, we apply a modeling approach to compare the potential of biovector transport to other physical transport pathways for a hypothetical lake receiving large numbers of fish. We conclude that biovector transport should not be neglected when considering environmental risks of biomagnifying contaminants.

  4. Chromium accumulation in submerged aquatic plants treated with tannery effluent at Kanpur, India.

    Science.gov (United States)

    Gupta, Kiran; Gaumat, Sumati; Mishra, Kumkum

    2011-09-01

    Aquatic macrophytes have been widely studied because of their capability of absorbing contaminants from water and their subsequent use in biomonitoring. This study presents a comparison of Cr accumulating potential of submerged aquatic plants viz Vallisneria spiralis and Hydrilla verticillata. These plants were treated with various concentrations of treated tannery effluent collected from UASB, Jajmau, Kanpur under repeated exposure in controlled laboratory conditions in order to assess their maximum bioaccumulation potential. The maximum accumulation of 385.6 and 201.6 microg g(-1) dry weight was found in roots of V. spiralis and the whole plants of H. verticillata, respectively at 100% concentration after 9th day of effluent exposure. The chlorophyll and protein content of both species decreased with increase in effluent concentration and duration. At highest concentration and duration a maximum reduction of 67.4 and 62.66% in total chlorophyll content, 9.97 and 4.66% in carotenoid content and 62.66 and 59.36% in protein content was found in V. spiralis and H. verticillata respectively. Anatomical studies in both V. spiralis and H. verticillata was carried out to assess the effects of metal accumulation within the plants. Changes in the anatomical structures of both plants exhibits the capacity of these species to act as indicator of effluent toxicity. The high accumulation potential of Cr by both plants revealed their capability to remove pollutants from effluent. PMID:22319874

  5. Cadmium tolerance and bioaccumulation of 18 hemp accessions.

    Science.gov (United States)

    Shi, Gangrong; Liu, Caifeng; Cui, Meicheng; Ma, Yuhua; Cai, Qingsheng

    2012-09-01

    Hemp (Cannabis sativa L.) is a fast-growing and high biomass producing plant species, which has been traditionally grown as multiple-use crop and recently considered as an energy crop. In order to screen accessions that can be cultivated in cadmium (Cd)-contaminated soils for biodiesel production, the ability of Cd tolerance and bioaccumulation of 18 hemp cultivars or ecotypes were evaluated in pot experiment under 25 mg Cd kg(-1) (dry weight, DW) soil condition, in terms of plant growth, pigment contents, chlorophyll fluorescence, and Cd accumulation at 45 days after seedling emergence. Results showed that seedlings of all cultivars, except USO-31, Shenyang and Shengmu, could grow quite well under 25 mg Cd kg(-1) (DW) soil condition. Among them, Yunma 1, Yunma 2, Yunma 3, Yunma 4, Qujing, Longxi, Lu'an, Xingtai, and Shuyang showed great biomass (>0.5 g plant(-1)), high tolerance factors (68.6-92.3%), and little reduction of pigment content and chlorophyll fluorescence under 25 mg Cd kg(-1) (DW) soil stress, indicating these cultivars had a strong tolerance to Cd stress and could be cultivated in Cd-contaminated soils. Cultivars Longxi, Lu'an, Xingtai, Yunma 2, Yunma 3, Yunma 4, and Qujing exhibited higher Cd concentrations and total Cd in shoots. These cultivars, therefore, are good candidates for the implementation of the new strategy of cultivating biodiesel crops for phytoremediation of Cd-contaminated soils.

  6. Optimizing fish sampling for fish - mercury bioaccumulation factors

    Science.gov (United States)

    Scudder Eikenberry, Barbara C.; Riva-Murray, Karen; Knightes, Christopher D.; Journey, Celeste A.; Chasar, Lia C.; Brigham, Mark E.; Bradley, Paul M.

    2015-01-01

    Fish Bioaccumulation Factors (BAFs; ratios of mercury (Hg) in fish (Hgfish) and water (Hgwater)) are used to develop Total Maximum Daily Load and water quality criteria for Hg-impaired waters. Both applications require representative Hgfish estimates and, thus, are sensitive to sampling and data-treatment methods. Data collected by fixed protocol from 11 streams in 5 states distributed across the US were used to assess the effects of Hgfish normalization/standardization methods and fish sample numbers on BAF estimates. Fish length, followed by weight, was most correlated to adult top-predator Hgfish. Site-specific BAFs based on length-normalized and standardized Hgfish estimates demonstrated up to 50% less variability than those based on non-normalized Hgfish. Permutation analysis indicated that length-normalized and standardized Hgfish estimates based on at least 8 trout or 5 bass resulted in mean Hgfish coefficients of variation less than 20%. These results are intended to support regulatory mercury monitoring and load-reduction program improvements.

  7. Bioaccumulation and bioavailability of polybrominated diphynel ethers (PBDEs) in soil

    Energy Technology Data Exchange (ETDEWEB)

    Liang Xianwei; Zhu Shuzhen; Chen Peng [College of Environmental Science and Engineering, Nankai University, Weijin Road 94, Tianjin 300071 (China); Key Laboratory of Pollution Processes and Environmental Criteria (Nankai University), Ministry of Education, Tianjin 300071 (China); Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, Nankai University, Tianjin 300071 (China); Zhu Lingyan, E-mail: zhuly@nankai.edu.c [College of Environmental Science and Engineering, Nankai University, Weijin Road 94, Tianjin 300071 (China); Key Laboratory of Pollution Processes and Environmental Criteria (Nankai University), Ministry of Education, Tianjin 300071 (China); Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, Nankai University, Tianjin 300071 (China)

    2010-07-15

    Earthworms were exposed to artificially contaminated soils of DE-71 and DE-79 to investigate the bioaccumulation and bioavailability of PBDEs in soil. All major congeners were bioavailable to earthworms. The uptake and elimination rate coefficients of PBDEs decreased with their logK{sub ow}s. The biota soil accumulation factors of PBDEs also declined with logK{sub ow}. These may be due to the large molecular size and the high affinity of PBDEs to soil particles. The concentrations extracted by Tenax for 6 h correlated very well with those found in earthworms, suggesting that the bioavailability of PBDEs in soil is related to the fraction of rapid desorption from soil. This also indicates that 6 h Tenax extraction is a good proxy for the bioavailability of PBDEs to earthworms in soil. The BSAFs of PBDEs in aged soil decreased 22-84% compared to freshly spiked soil, indicating that aging may diminish the bioavailability of PBDEs in soil significantly. - PBDEs are bioavailable to earthworms in soil and the uptake and elimination rate coefficients and BSAFs declined with their logK{sub ow}s.

  8. Persistence and bioaccumulation of oxyfluorfen residues in onion.

    Science.gov (United States)

    Sondhia, Shobha

    2010-03-01

    A field study was conducted to determine persistence and bioaccumulation of oxyflorfen residues in onion crop at two growth stages. Oxyfluorfen (23.5% EC) was sprayed at 250 and 500 g ai/ha on the crop (variety, N53). Mature onion and soil samples were collected at harvest. Green onion were collected at 55 days from each treated and control plot and analyzed for oxyfluorfen residues by a validated high-performance liquid chromatography method with an accepted recovery of 78-92% at the minimum detectable concentration of 0.003 microg g(-1). Analysis showed 0.015 and 0.005 microg g(-1) residues of oxyfluorfen at 250 g a.i. ha(-1) rate in green and mature onion samples, respectively; however, at 500 g a.i.ha(-1) rates, 0.025 and 0.011 microg g(-1) of oxyfluorfen residues were detected in green and mature onion samples, respectively. Soil samples collected at harvest showed 0.003 and 0.003 microg g(-1) of oxyfluorfen residues at the doses 250 and 500 g a.i. ha(-1), respectively. From the study, a pre-harvest interval of 118 days for onion crop after the herbicide application is suggested. PMID:19238567

  9. Bioaccumulation of Hg in the mushroom Pleurotus ostreatus

    Energy Technology Data Exchange (ETDEWEB)

    Bressa, G.; Cima, L.; Costa, P.

    1988-10-01

    The possibility of utilizing industrial, urban, and other wastes for the growth of a product which is directly edible by humans is fascinating. However, it is possible that many wastes containing toxic substances, for example, heavy metals, could reach the food chain and produce adverse effects on human health. To this end, we studied the possibility of bioaccumulation of Hg by a mushroom, Pleurotus ostreatus, grown on an artificial compost containing this element. Concentrations of 0.05, 0.1, and 0.2 mg/kg of Hg as Hg(NO/sub 3/)/sub 2/.H/sub 2/O were added to three groups of the same compost, successively inoculated with the mycelia of the mushroom. Higher concentrations strongly reduced the growth of the mycelia and therefore were not utilized. The concentrations of Hg in the substrate and in the mushroom were evaluated by AAS. The range of the accumulation factor was found to be 65-140, i.e., very marked. This finding suggests that the cultivation of P. ostreatus on substrates containing Hg from industrial and urban wastes could involve possible risks to human health.

  10. Bioaccumulation and biosorption of chromium by Aspergillus niger MTCC 2594.

    Science.gov (United States)

    Sandana Mala, John Geraldine; Unni Nair, Balachandran; Puvanakrishnan, Rengarajulu

    2006-06-01

    Chromium toxicity is of prime concern due to chrome tanning processes in the leather sector. Chrome tanning results in the discharge of toxic levels of chromium causing pollution hazards. Chromium levels of Cr(III) and Cr(VI) were high above permissible limits in chrome samples after chrome tanning. The potential of Aspergillus niger MTCC 2594 to accumulate chromium as well as its biosorption capacity is investigated in this study. Bioaccumulation of Cr(III) and Cr(VI) in the spent chrome liquor has resulted in a 75-78% reduction of the initial Cr content in 24-36 h. A. niger biomass is found to be very effective in the biosorption of Cr(III) and Cr(VI) in spent chrome liquor. Maximum adsorption of 83% for biosorption of Cr(III) at 48 h and 79% of Cr(VI) at 36 h in spent chrome liquor is observed. The biosorption characteristics fit well with Langmuir and Freundlich isotherms and the adsorption parameters are evaluated. The biosorption of Cr also follows Lagergren kinetics. A. niger biomass is effectively used for the biosorption of chromium with 79-83% Cr removal in 36-48 h.

  11. Heavy metal bioaccumulation by wild edible saprophytic and ectomycorrhizal mushrooms.

    Science.gov (United States)

    Širić, Ivan; Humar, Miha; Kasap, Ante; Kos, Ivica; Mioč, Boro; Pohleven, Franc

    2016-09-01

    Heavy metals cause serious problems in the environment, and they can be accumulated in organisms, especially in the higher fungi. The concentration of Ni, Cr, Pb, Cd, and Hg in 10 species of edible mushrooms in Medvednica Nature Park, Croatia was therefore determined. In addition, the similarity between the studied species was determined by cluster analysis based on concentrations of the aforementioned metals in the fruiting bodies. The contents of nickel, chromium, lead, cadmium, and mercury in the fruiting bodies of mushrooms were obtained by X-ray fluorescence spectrometry. The highest concentrations of Ni (3.62 mg kg(-1)), Cr (3.01 mg kg(-1)), and Cd (2.67 mg kg(-1)) were determined in Agaricus campestris. The highest concentration of Pb (1.67 mg kg(-1)) was determined in Macrolepiota procera, and the highest concentration of Hg (2.39 mg kg(-1)) was determined in Boletus edulis. The concentration of all heavy metals significantly differed (p Cr, and Pb and bioaccumulators of Cd and Hg. Cluster analysis performed on the basis of the accumulation of the studied metals revealed great phenotypic similarity of mushroom species belonging to the same genus and partial similarity of species of the same ecological affiliation. PMID:27272918

  12. Assessing the impact of global change on micropollutants in aquatic ecosystems: Modelling the fate of nonylphenolic compounds in the Seine River

    OpenAIRE

    Cladière, Mathieu; Bonhomme, Céline; Vilmin, Lauriane; Gasperi, Johnny; Flipo, Nicolas; Habets, Florence; Tassin, Bruno

    2013-01-01

    This study aims at modelling the annual variability in concentrations of nonylphenolic compounds such as 4 nonylphenol (4-NP), nonylphenol monoethoxylate (NP1EO) and nonylphenoxy acetic acid (NP1EC) within the Seine River in the Paris metropolitan area. These compounds are of prime interest because the 4-NP is a well known endocrine disrupting chemical, while NP1EO and NP1EC are expected to be biodegraded into 4-NP in the environment (Giger et al. 2009). Thus the potential consequence of clim...

  13. Colorado Plateau Rapid Ecoregion Assessment Conservation Elements: Aquatic Intactness (HUC5)

    Data.gov (United States)

    Bureau of Land Management, Department of the Interior — This map provides an estimate of current and near-term aquatic intactness, which is based on the results of a fuzzy logic model integrating land use, water quality,...

  14. Development of criteria for an ecotoxicological examination procedure by differentially high integrated parts of aquatic model ecosystems and mathematical models. Final report. Erarbeitung von oekosystemaren Bewertungsstrategien zur Beurteilung der Umweltgefaehrlichkeit von Chemikalien mit Hilfe von unterschiedlich hoch integrierten aquatischen Modelloekosystemausschnitten und mathematischen Modellen. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Huber, W. (Technische Univ. Muenchen, Weihenstephan (Germany). Inst. fuer Landespflege und Botanik); Zieris, F.J. (Technische Univ. Muenchen, Weihenstephan (Germany). Inst. fuer Landespflege und Botanik); Lay, J.P. (GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Bodenoekologie); Weiss, K. (GSF - Forschungszentrum fuer Umwelt und Gesundhe

    1994-02-28

    It is difficult to assess the risks of environmental toxicants, especially when they have to be extrapolated from laboratory datas. Therefore efforts are made to determine the potential hazards of chemicals with the help of artificial ecosystems or parts of them. These kinds of test systems are similar to the structure and function of natural ecosystems and therefore allow to make representative extrapolations to real nature. As a disadvantage they are expensive and not yet standardized. To be accepted for the risk assessment of chemicals it was attempted to standardize artificial aquatic ecosystems in this project. It was tried to minimize the costs of the testing procedures by using a mathematical model simulating artificial littoral ecosystems. With increasing complexity of the system a better description of expected effects caused by a substance in environment can be given. With the help of outdoor ecosystems the threshold concentration of a chemical could be determined that is not likely to affect an aquatic ecosystem. Further we succeeded in providing a prototype modeling the effects in the microcosms used in our experiments. This model is able to approximately describe the behavior of macrophytes, algae, and secondary consumers in uncontaminated and contaminated systems (with the test chemical atrazine). (orig.)

  15. Phytotoxic effects of cyanobacteria extract on the aquatic plant Lemna gibba: microcystin accumulation, detoxication and oxidative stress induction.

    Science.gov (United States)

    Saqrane, Sana; Ghazali, Issam El; Ouahid, Youness; Hassni, Majida El; Hadrami, Ismaïl El; Bouarab, Lahcen; del Campo, Franscica F; Oudra, Brahim; Vasconcelos, Vitor

    2007-08-01

    The occurrence of toxic cyanobacteria in the aquatic environment constitutes a serious risk for the ecological balance and the functioning of ecosystems. The presence of cyanotoxins in ecosystems could have eventual adverse effects on aquatic plants, which play an important biological role as primary producers. The original aim of this study was to investigate microcystin (MC) accumulation, detoxication and oxidative stress induction in the free-floating aquatic vascular plant Lemna gibba (Duckweed, Lemnaceae). Experiments were carried out with a range of MC levels, obtained from toxic Microcystis culture extracts (0.075, 0.15, 0.22 and 0.3 microg equiv.MC-LR mL(-1)). During chronic exposure of the plant to MC, we examined the growth, photosynthetic pigment contents and also the physiological behavior related to toxin accumulation, possible biodegradation and stress oxidative processes of L. gibba. For the last reason, changes in peroxidase activity and phenol compound content were determined. This is a first report using phenol compounds as indicators of biotic stress induced by MC contamination in aquatic plants. Following MC exposure, a significant decrease of plant growth and chlorophyll content was observed. Also, it was demonstrated that L. gibba could take up and bio-transform microcystins. A suspected MC degradation metabolite was detected in treated Lemna cells. In response to chronic contamination with MCs, changes in the peroxidase activity and qualitative and quantitative changes in phenolic compounds were observed after 24h of plant exposure. The physiological effects induced by chronic exposure to microcystins confirm that in aquatic ecosystems plants coexisting with toxic cyanobacterial blooms may suffer an important negative ecological impact. This may represent a sanitary risk due to toxin bioaccumulation and biotransfer through the food chain. PMID:17582520

  16. Hazardous materials in aquatic environments of the Mississippi River Basin

    International Nuclear Information System (INIS)

    Tulane and Xavier Universities have singled out the environment as a major strategic focus for research and training for now and by the year 2000. In December, 1992, the Tulane/Xavier CBR was awarded a five year grant to study pollution in the Mississippi River system. The ''Hazardous Materials in Aquatic Environments of the Mississippi River Basin'' project is a broad research and education program aimed at elucidating the nature and magnitude of toxic materials that contaminate aquatic environments of the Mississippi River Basin. Studies include defining the complex interactions that occur during the transport of contaminants, the actual and potential impact on ecological systems and health, and the mechanisms through which these impacts might be remediated. The Mississippi River Basin represents a model system for analyzing and solving contamination problems that are found in aquatic systems world-wide. These research and education projects are particularly relevant to the US Department of Energy's programs aimed at addressing aquatic pollution problems associated with DOE National Laboratories. First year funding supported seven collaborative cluster projects and twelve initiation projects. This report summarizes research results for period December 1992--December 1993

  17. Impact of Organic Contamination on Some Aquatic Organisms

    Science.gov (United States)

    Yasser, El-Nahhal; Shawkat, El-Najjar; Samir, Afifi

    2015-01-01

    Background: Contamination of water systems with organic compounds of agricultural uses pose threats to aquatic organisms. Carbaryl, chlorpyrifos, and diuron were considered as model aquatic pollutants in this study. The main objective of this study was to characterize the toxicity of organic contamination to two different aquatic organisms. Materials and Methods: Low concentrations (0.0–60 µmol/L) of carbaryl, diuron and very low concentration (0.0–0.14 µmol/L) of chlorpyrifos and their mixtures were tested against fish and Daphnia magna. Percentage of death and immobilization were taken as indicators of toxicity. Results: Toxicity results to fish and D. magna showed that chlorpyrifos was the most toxic compound (LC50 to fish and D. magna are 0.08, and 0.001 µmol/L respectively), followed by carbaryl (LC50 to fish and D. magna are 43.19 and 0.031 µmol/L), while diuron was the least toxic one (LC50 values for fish and D. magna are 43.48 and 32.11 µmol/L respectively). Mixture toxicity (binary and tertiary mixtures) showed antagonistic effects. Statistical analysis showed a significant difference among mixture toxicities to fish and D. magma. Conclusion: Fish and D. magam were sensitive to low concentrations. These data suggest potent threats to aquatic organisms from organic contamination. PMID:26862260

  18. The NEON Aquatic Network: Expanding the Availability of Biogeochemical Data

    Science.gov (United States)

    Vance, J. M.; Bohall, C.; Fitzgerald, M.; Utz, R.; Parker, S. M.; Roehm, C. L.; Goodman, K. J.; McLaughlin, B.

    2013-12-01

    /sediment chemistry, aquatic organisms, geomorphology). The aquatic network will produce ~212 low-level data products for each site. NEON will produce several higher level data products such as measurements of whole-stream metabolism, gross primary productivity, ecosystem respiration, and fluxes of nitrogen, phosphorous and carbon that will enable users to analyze processes on a gross scale. These data may be integrated with NEON's terrestrial and airborne networks to bridge the gap between aquatic and terrestrial biogeochemical research. The NEON Aquatic Network is poised to greatly expand our ability to create more robust biogeochemical models. For example, hydrologic and stable isotope data will allow investigation of terrestrial-aquatic carbon flux. Constraints provided by NEON's terrestrial and atmospheric data concurrent with remotely sensed data will facilitate the scaling to regional and continental scales, potentially leading to greater accuracy in the global carbon budget. The NEON Aquatic Network represents a powerful tool that will give the scientific community access to standardized data over spatiotemporal scales that are needed to answer fundamental questions about natural ecological variability and responses to changes in the environment.

  19. Aquatic Therapy: A Viable Therapeutic Recreation Intervention.

    Science.gov (United States)

    Broach, Ellen; Dattilo, John

    1996-01-01

    Reviews literature on the effects of aquatic therapy (swimming and exercise) to improve function. Research shows that aquatic therapy has numerous psychological and physical benefits, and it supports the belief that participation can provide a realistic solution to maintaining physical fitness and rehabilitation goals while engaging in enjoyable…

  20. Purification of Water by Aquatic Plants

    OpenAIRE

    Morimitsu, Katsuhito; Kawahigashi, Tatsuo

    2013-01-01

    [Abstract] Water quality purification of many water systems including those occurring in rivers depends to a great degree on water quality purification activities of aquatic plants and microbes. This paper presents a discussion of results, based on laboratory experiments, of purification by aquatic plants.

  1. Estimating Aquatic Insect Populations. Introduction to Sampling.

    Science.gov (United States)

    Chihuahuan Desert Research Inst., Alpine, TX.

    This booklet introduces high school and junior high school students to the major groups of aquatic insects and to population sampling techniques. Chapter 1 consists of a short field guide which can be used to identify five separate orders of aquatic insects: odonata (dragonflies and damselflies); ephemeroptera (mayflies); diptera (true flies);…

  2. Control of Fish and Aquatic Plants.

    Science.gov (United States)

    Hesser, R. B.; And Others

    This agriculture extension service publication from Pennsylvania State University is a handbook for the water body manager. The bulk of the contents deals with aquatic plant control. The different types of aquatic plants, their reproduction and growth, and their role in the ecology of the water body are introduced in this main section. Also, the…

  3. Hungry Horse Dam Fisheries Mitigation; Aquatic Modeling of the Selective Withdrawal System, Hungry Horse Dam, Montana, 1991-1993 Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Marotz, Brian L.; Althen, Craig; Gustafson, Daniel

    1994-04-01

    Hungry Horse Dam presently releases frigid water from the bottom of the reservoir all year long. Cold water effects insect production and fish growth downstream. Rapid temperature changes of up to 8.3 C (14 F) have been measured in the Flathead River downstream of the South Fork confluence, controlled by dam discharges. Thermal effects from Hungry Horse Dam are detectable for over 64 Km downstream to Flathead Lake. The installation of a selective withdrawal structure on each of the dam`s discharge penstocks was determined to be the most cost-effective means to provide constant, permanent temperature control without impacting power production and flexibility in dam operation. The thermal model presented herein revealed that fish growth potential in the river would increase two to five times through selective withdrawal, temperature control. Temperature control is possible over the entire range of turbine discharge capacity, with very little effect on power production. Findings indicate that angling would improve through higher catch rates and larger fish. Temperature control will solve the most serious impact to river health. However, flow fluctuations will continue to effect insect production and usable fishery habitat in the Flathead River. A natural thermal regime combined with moderated flow fluctuation would further enhance riverine food production, trout growth and recreation potential.

  4. Effects of nano-TiO2 on perfluorooctanesulfonate bioaccumulation in fishes living in different water layers: Implications for enhanced risk of perfluorooctanesulfonate.

    Science.gov (United States)

    Qiang, Liwen; Pan, Xiaoyu; Zhu, Lingyan; Fang, Shuhong; Tian, Shengyan

    2016-01-01

    Nano-titanium dioxide (nano-TiO2) is one of the most universal engineered nano-materials while perfluorooctanesulfonate (PFOS) is a typical new persistent organic pollutant. They are widely used and present in aquatic environment. In this study, a novel semi-static multilayer microcosm was setup to investigate the impacts of nano-TiO2 on PFOS bioaccumulation in fish species [Danio rerio (D. rerio), Ctenopharyngodon idella (C. idella), Hypostomus plecostomus (H. plecostomus)] living in different vertical layers. As a result of aggregation and deposition, the concentration of TiO2 increased from upper to bottom layers in the water column. Concomitantly, due to adsorption of PFOS on the nano-TiO2 particles, PFOS also displayed an increasing trend from upper to bottom layer. Owing to ingestion of the TiO2-PFOS complexes, more PFOS was taken-up by fish. With the aid of intestinal fluid, PFOS was readily released from TiO2 particles and absorbed by fish. As a result, accumulation of PFOS in whole fish was facilitated and the bioaccumulation factors of PFOS in D. rerio, C. idella and H. plecostomus were 3.01, 2.42 and 1.11 times of that in the groups without TiO2. However, TiO2 aggregates were too large to penetrate biological membranes to participate body circulation, and no significant accumulation of TiO2 was observed in fish muscle. The results suggested that the ecological risk of PFOS could be enhanced due to the presence of nano-TiO2 in water.

  5. Bio-accumulation kinetics of radioruthenium in marine bivalves. Laboratory study

    International Nuclear Information System (INIS)

    Three kinds of marine bivalves (wild Saccostrea cucullata, aquacultured Perna viridis and aquacultured Pinctada martens), collected from Daya Bay, the South China Sea, were used to investigate the bio-accumulation of radioruthenium in the glass aquarium with natural seawater (pH 8.20, 35 per mille salinity, filtered by 0.45 μm) at ambient temperature under laboratory feeding conditions. The experimental results show that the stead-state of biology concentration factor (BCF, ml/g) of radioruthenium was approached around 6 days for most species of bivalves. The values of BCF in shells are the highest in organs all the three bivalves. The orders of BCF values (ml x g-1) are as: Perna viridis (33.2) < Saccostrea cucullata (47.0) < Pinctada martensi (208.4) for shells and Saccostrea cucullata (1.5) < Pinctada martensi (2.2) ∼ Perma viridis (2.4) for soft tissues, respectively, after exposed for 14 days. The rate constants of uptake and elimination of radioruthenium on marine bivalves were also discussed by first-order kinetics model. The Pinctada martensi may be applicable to be an indictor for monitoring radioruthenium among the three bivalves. (author)

  6. Bioaccumulation of cesium-137 in yellow bullhead catfish (Ameiurus natalis) inhabiting an abandoned nuclear reactor reservoir

    International Nuclear Information System (INIS)

    Bioaccumulation of 137Cs was investigated in yellow bullhead catfish (Ameiurus natalis) inhabiting an abandoned reactor reservoir, Pond B, Savannah River Site, Barnwell Co., South Carolina. The authors collected fish by trap-netting, and determined ages from pectoral spines. Muscle and other tissues were assayed for 137Cs by NaI-scintillation. Music 137Cs was unrelated to sex or mass of fish, but was related to age. Examination of least-squares means suggested that 137Cs in muscle increased up to about age 3, but did not increase with greater age. A modified Richards model showed equilibrium 137Cs concentration in muscle was acquired in approximately 2.4 years. Growth differed between sexes and the time to asymptotic body mass was longer than the time to attain equilibrium 137Cs concentration. Males attained an asymptotic mass of 577 g in approximately 6.3 years; females attained an asymptotic mass of 438 g in approximately 5.9 years. The cumulative 137Cs burden of the population was 4.9 x 106 Bq, representing 137Cs inventory of the reservoir. Concentration of 137Cs varied among tissues with gill and muscle the lowest and highest. Concentration of 137Cs in ovaries declined with increasing ovary mass. Until equilibrium is attained in these fish, 137Cs concentration is directly related to increasing age rather than size

  7. Effects of cadmium on bioaccumulation and biochemical stress response in rice (Oryza sativa L.).

    Science.gov (United States)

    Xie, Pan-pan; Deng, Juan-wei; Zhang, Hui-min; Ma, You-hua; Cao, De-ju; Ma, Ru-xiao; Liu, Ren-jing; Liu, Cheng; Liang, Yue-gan

    2015-12-01

    This study investigated the effects of various Cd concentrations on the bioaccumulation, antioxidative defense, and stress responses of rice (Oryza sativa L.). The distribution characteristics of Cd in rice were in the following order: roots>stems>grains. The bioconcentration factor values of Cd increased at concentrations lower than 3.00 mg Cd/kg and approximately decreased to a constant value at concentrations higher than 3.00 mg Cd/kg. Rice showed a higher Cd accumulation potential at low Cd concentrations than at high Cd concentrations. The Freundlich isotherm model described well the adsorption isotherms of Cd in rice roots. The biosorption mechanism of rice roots was determined to be cooperative adsorption. The malondialdehyde (MDA) content increased at a concentration range of 0.00-5.00 mg/L, indicating the enhancement of lipid peroxidation. By contrast, the MDA content slightly decreased at concentrations higher than 5.00 mg/L. Peroxidase (POD) activity exhibited active response to oxidative stress at concentrations lower than 5.00 mg/L but was inhibited at concentrations higher than 5.00 mg/L. The response to Cd stress of the N-H, O-H and C-O functional groups in rice shoots was observed via Fourier transform infrared spectroscopy.

  8. Phytoremediation potential of aquatic macrophyte, Azolla.

    Science.gov (United States)

    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. PMID:22396093

  9. Effects of Zinc and Lead Toxicity on the Growth and their Bioaccumulation in Fish

    Directory of Open Access Journals (Sweden)

    M. Javed

    2012-06-01

    Full Text Available This study evaluated the impacts of chronic exposure of waterborne zinc (Zn and lead (Pb on the growth and their bioaccumulation in three fish species viz. Catla catla, Labeo rohita and Cirrhina mrigala. Three fish species responded similarly for their feed intakes while weight increments and feed conversion efficiency (FCE varied significantly due to Zn and Pb exposures. Younger fish were significantly more sensitive to metallic ion toxicity. Chronic exposure of both Zn and Pb (at 1/3rd of LC50 to the fish caused significantly lesser gain in weight, feed intakes and FCE than that of control (un-stressed fish. Amongst 9 age groups, 330-day fish exhibited significantly better growth in terms of weight gain and feed intake than the other age groups. Both Zn and Pb bioaccumulations varied significantly among fish organs while the patterns of their bioaccumulation did not vary significantly within three fish species. Fish liver and kidney accumulated significantly higher Zn and Pb during chronic exposures. However, Zn accumulation was significantly more than that of Pb in the fish body. Amongst three fish species, Labeo rohita exhibited significantly higher tendency to accumulate Zn while Catla catla amassed higher Pb in its body. The bioaccumulation of both Zn and Pb was positively dependent upon fish age and exposure concentration of metals. Zn bioaccumulation in fish body followed the order: liver>kidney>skin>gills>scale=muscle while that of Pb was: kidney>liver>gills>skin>muscle=scales.

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

    International Nuclear Information System (INIS)

    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

  11. Organochlorine pollution in tropical rivers (Guadeloupe): Role of ecological factors in food web bioaccumulation

    Energy Technology Data Exchange (ETDEWEB)

    Coat, Sophie, E-mail: coatsophie@gmail.com [EA 926 DYNECAR, Laboratoire de Biologie Marine, UFR Sciences, Universite des Antilles et de la Guyane, BP592, 97159 Pointe-a-Pitre Cedex (France); Monti, Dominique, E-mail: dominique.monti@univ-ag.fr [EA 926 DYNECAR, Laboratoire de Biologie Marine, UFR Sciences, Universite des Antilles et de la Guyane, BP592, 97159 Pointe-a-Pitre Cedex (France); Legendre, Pierre, E-mail: pierre.legendre@umontreal.ca [Departement de Sciences Biologique, Universite de Montreal, C.P. 6128, succursale A, Montreal, Quebec H3C 3J7 (Canada); Bouchon, Claude, E-mail: claude.bouchon@univ-ag.fr [EA 926 DYNECAR, Laboratoire de Biologie Marine, UFR Sciences, Universite des Antilles et de la Guyane, BP592, 97159 Pointe-a-Pitre Cedex (France); Massat, Felix, E-mail: fmassat@ladrome.fr [LDA26, laboratoire Departemental d' Analyses de la Drome, 27 avenue Lautagne, 26000 Valence (France); Lepoint, Gilles, E-mail: g.lepoint@ulg.ac.be [MARE Centre, Laboratoire d' Oceanologie, Universite de Liege, Bat. B6, 4000 Sart Tilman, Belgique (Belgium)

    2011-06-15

    Concentrations of organochlorine pesticides and stable isotope ratios of nitrogen and carbon were measured in a tropical freshwater ecosystem to evaluate the contamination level of biota and examine the bioaccumulation patterns of pollutants through the food web. Chemical analyses showed a general and heavy contamination of the entire food web. They revealed the strong accumulation of pollutants by juveniles of diadromous fishes and shrimps, as they re-enter the river. The role of ecological factors in the bioaccumulation of pesticides was evaluated. Whereas the most persistent pollutants (chlordecone and monohydro-chlordecone) were related to the organisms diet and habitat, bioaccumulation of {beta}-HCH was only influenced by animal lipid content. The biomagnification potential of chlordecone through the food chain has been demonstrated. It highlighted the importance of trophic transfer in this compound bioaccumulation process. In contrast, bioconcentration by passive diffusion from water seemed to be the main exposure route of biota to {beta}-HCH. - Highlights: > We measured OC pesticides and stable isotope ratios in a tropical stream. > Results showed a strong and ubiquitous contamination of the entire food web. > Diadromous juveniles strongly accumulated pollutants when they re-enter the river. > The most persistent pollutant (chlordecone) was related to species diet and habitat. > {beta}-HCH was only influenced by animal lipid content. - This paper determines the bioaccumulation and transfer processes of organochlorine pesticides within the stream food web in Guadeloupe (Caribbean).

  12. Organochlorine pollution in tropical rivers (Guadeloupe): Role of ecological factors in food web bioaccumulation

    International Nuclear Information System (INIS)

    Concentrations of organochlorine pesticides and stable isotope ratios of nitrogen and carbon were measured in a tropical freshwater ecosystem to evaluate the contamination level of biota and examine the bioaccumulation patterns of pollutants through the food web. Chemical analyses showed a general and heavy contamination of the entire food web. They revealed the strong accumulation of pollutants by juveniles of diadromous fishes and shrimps, as they re-enter the river. The role of ecological factors in the bioaccumulation of pesticides was evaluated. Whereas the most persistent pollutants (chlordecone and monohydro-chlordecone) were related to the organisms diet and habitat, bioaccumulation of β-HCH was only influenced by animal lipid content. The biomagnification potential of chlordecone through the food chain has been demonstrated. It highlighted the importance of trophic transfer in this compound bioaccumulation process. In contrast, bioconcentration by passive diffusion from water seemed to be the main exposure route of biota to β-HCH. - Highlights: → We measured OC pesticides and stable isotope ratios in a tropical stream. → Results showed a strong and ubiquitous contamination of the entire food web. → Diadromous juveniles strongly accumulated pollutants when they re-enter the river. → The most persistent pollutant (chlordecone) was related to species diet and habitat. → β-HCH was only influenced by animal lipid content. - This paper determines the bioaccumulation and transfer processes of organochlorine pesticides within the stream food web in Guadeloupe (Caribbean).

  13. Bioaccumulation factor of {sup 137}Cs in some marine biotas from West Bangka Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Suseno, Heny, E-mail: henis@batan.go.id [Radioactive Waste Technology Center - The Indonesia Nuclear Energy Agency (BATAN) (Indonesia)

    2014-03-24

    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.

  14. Cyanobacteria and prawn farming in northern New South Wales, Australia--a case study on cyanobacteria diversity and hepatotoxin bioaccumulation

    International Nuclear Information System (INIS)

    Harmful cyanobacteria pose a hazard to aquatic ecosystems due to toxins (hepatotoxic microcystins, nodularins, and cylindrospermopsin) they produce. The microcystins and nodularins are potent toxins, which are also tumor promoters. The microcystins and nodularins may accumulate into aquatic organisms and be transferred to higher trophic levels, and eventually affect vector animals and consumers. Prawn farming is a rapidly growing industry in Australia. Because information regarding effects of cyanobacteria at prawn farms was lacking, we examined diversity of cyanobacteria and toxin production plus bioaccumulation into black tiger prawns (Penaeus monodon) under both field (northern New South Wales, Australia, December 2001-April 2002) and laboratory conditions. Samples were analyzed for hepatotoxins using enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC). The maximum density of cyanobacteria (1 x 106 to 4 x 106 cells/l) was reached in April. Cyanobacteria encountered were Oscillatoria sp. (up to 4 x 106 cells/l), Pseudanabaena sp. (up to 1.8 x 106 cells/l), Microcystis sp. (up to 3.5 x 104 cells/l), and Aphanocapsa sp. (up to 2 x 104 cells/l). An uncommon cyanobacterium, Romeria sp. (up to 2.2 x 106 cells/l), was also observed. Contrasting earlier indications, toxic Nodularia spumigena was absent. Despite that both Oscillatoria sp. and Microcystis sp. are potentially hepatotoxic, hepatotoxin levels in phytoplankton samples remained low (up to 0.5-1.2 mg/kg dw; ELISA) in 2001-2002. ELISA was found suitable not only for phytoplankton but prawn tissues as well. Enzymatic pretreatment improved extractability of hepatotoxin from cyanobacteria (nodularin from N. spumigena as an example), but did not generally increase toxin recovery from prawn hepatopancreas. There were slightly increasing hepatotoxin concentrations in prawn hepatopancreas (from 6-20 to 20-80 μg/kg dw; ELISA) during the study. Hepatotoxin concentrations in

  15. Mercury bioaccumulation and biomagnification in a small Arctic polynya ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Clayden, Meredith G., E-mail: meredith.clayden@gmail.com [Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB E2L 4L5 (Canada); Arsenault, Lilianne M. [Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB E2L 4L5 (Canada); Department of Earth and Environmental Science, Acadia University, Wolfville, NS B4P 2R6 (Canada); Department of Biology, Acadia University, Wolfville, NS B4P 2R6 (Canada); Kidd, Karen A. [Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB E2L 4L5 (Canada); O' Driscoll, Nelson J. [Department of Earth and Environmental Science, Acadia University, Wolfville, NS B4P 2R6 (Canada); Mallory, Mark L. [Department of Biology, Acadia University, Wolfville, NS B4P 2R6 (Canada)

    2015-03-15

    Recurring polynyas are important areas of biological productivity and feeding grounds for seabirds and mammals in the Arctic marine environment. In this study, we examined food web structure (using carbon and nitrogen isotopes, δ{sup 13}C and δ{sup 15}N) and mercury (Hg) bioaccumulation and biomagnification in a small recurring polynya ecosystem near Nasaruvaalik Island (Nunavut, Canada). Methyl Hg (MeHg) concentrations increased by more than 50-fold from copepods (Calanus hyperboreus) to Arctic terns (Sterna paradisaea), the abundant predators at this site. The biomagnification of MeHg through members of the food web – using the slope of log MeHg versus δ{sup 15}N – was 0.157 from copepods (C. hyperboreus) to fish. This slope was higher (0.267) when seabird chicks were included in the analyses. Collectively, our results indicate that MeHg biomagnification is occurring in this small polynya and that its trophic transfer is at the lower end of the range of estimates from other Arctic marine ecosystems. In addition, we measured Hg concentrations in some poorly studied members of Arctic marine food webs [e.g. Arctic alligatorfish (Ulcina olrikii) and jellyfish, Medusozoa], and found that MeHg concentrations in jellyfish were lower than expected given their trophic position. Overall, these findings provide fundamental information about food web structure and mercury contamination in a small Arctic polynya, which will inform future research in such ecosystems and provide a baseline against which to assess changes over time resulting from environmental disturbance. - Highlights: • Polynyas are recurring sites of open water in polar marine areas • Mercury (Hg) biomagnification was studied in a small polynya near Nasaruvaalik Island, NU, Canada • Hg biomagnification estimates for invertebrates to fish were low compared to other Arctic systems • Factors underlying this result are unknown but may relate to primary productivity in small polynyas.

  16. Bioaccumulation and maternal transfer of mercury and selenium in amphibians.

    Science.gov (United States)

    Bergeron, Christine M; Bodinof, Catherine M; Unrine, Jason M; Hopkins, William A

    2010-04-01

    Amphibian population declines have been documented worldwide and environmental contaminants are believed to contribute to some declines. Maternal transfer of bioaccumulated contaminants to offspring may be an important and overlooked mechanism of impaired reproductive success that affects amphibian populations. Mercury (Hg) is of particular concern due to its ubiquity in the environment, known toxicity to other wildlife, and complex relationships with other elements, such as selenium (Se). The objectives of the present study were to describe the relationships between total Hg (THg), methlymercury (MMHg), and Se in three amphibian species (Plethodon cinereus, Eurycea bislineata cirrigera, and Bufo americanus) along a Hg-polluted river and floodplain, and to determine if B. americanus maternally transfers Hg and Se to its eggs in a tissue residue-dependent manner. Total Hg and MMHg concentrations in all species spanned two orders of magnitude between the reference and contaminated areas, while Se concentrations were generally low in all species at both sites. Strong positive relationships between THg and MMHg in tissues of all species were observed throughout. Both Hg and Se were maternally transferred from females to eggs in B. americanus, but the percentage of the females' Hg body burden transferred to eggs was low compared with Se. In addition, Hg concentrations appeared to positively influence the amount of Se transferred from female to eggs. The present study is the first to confirm a correlation between Hg concentrations in female carcass and eggs in amphibians and among the first to describe co-transference of Se and Hg in an anamniotic vertebrate. The results suggest future work is needed to determine whether maternal transfer of Hg has transgenerational implications for amphibian progeny.

  17. Mercury bioaccumulation and biomagnification in a small Arctic polynya ecosystem

    International Nuclear Information System (INIS)

    Recurring polynyas are important areas of biological productivity and feeding grounds for seabirds and mammals in the Arctic marine environment. In this study, we examined food web structure (using carbon and nitrogen isotopes, δ13C and δ15N) and mercury (Hg) bioaccumulation and biomagnification in a small recurring polynya ecosystem near Nasaruvaalik Island (Nunavut, Canada). Methyl Hg (MeHg) concentrations increased by more than 50-fold from copepods (Calanus hyperboreus) to Arctic terns (Sterna paradisaea), the abundant predators at this site. The biomagnification of MeHg through members of the food web – using the slope of log MeHg versus δ15N – was 0.157 from copepods (C. hyperboreus) to fish. This slope was higher (0.267) when seabird chicks were included in the analyses. Collectively, our results indicate that MeHg biomagnification is occurring in this small polynya and that its trophic transfer is at the lower end of the range of estimates from other Arctic marine ecosystems. In addition, we measured Hg concentrations in some poorly studied members of Arctic marine food webs [e.g. Arctic alligatorfish (Ulcina olrikii) and jellyfish, Medusozoa], and found that MeHg concentrations in jellyfish were lower than expected given their trophic position. Overall, these findings provide fundamental information about food web structure and mercury contamination in a small Arctic polynya, which will inform future research in such ecosystems and provide a baseline against which to assess changes over time resulting from environmental disturbance. - Highlights: • Polynyas are recurring sites of open water in polar marine areas • Mercury (Hg) biomagnification was studied in a small polynya near Nasaruvaalik Island, NU, Canada • Hg biomagnification estimates for invertebrates to fish were low compared to other Arctic systems • Factors underlying this result are unknown but may relate to primary productivity in small polynyas

  18. Measurement of undisturbed di-nitrogen emissions from aquatic ecosystems

    Science.gov (United States)

    Qin, Shuping, Clough, Timothy, Lou, Jiafa; Hu, Chunsheng; Oenema, Oene; Wrage-Mönnig, Nicole; Zhang, Yuming

    2016-04-01

    Increased production of reactive nitrogen (Nr) from atmospheric di-nitrogen (N2) during the last century has greatly contributed to increased food production1-4. However, enriching the biosphere with Nr through N fertilizer production, combustion, and biological N2 fixation has also caused a series of negative effects on global ecosystems 5,6, especially aquatic ecosystems7. The main pathway converting Nr back into the atmospheric N2 pool is the last step of the denitrification process, i.e., the reduction of nitrous oxide (N2O) into N2 by micro-organisms7,8. Despite several attempts9,10, there is not yet an accurate, fast and direct method for measuring undisturbed N2 fluxes from denitrification in aquatic sediments at the field scale11-14. Such a method is essential to study the feedback of aquatic ecosystems to Nr inputs1,2,7. Here we show that the measurement of both N2O emission and its isotope signature can be used to infer the undisturbed N2 fluxes from aquatic ecosystems. The microbial reduction of N2O increases the natural abundance of 15N-N2O relative to 14N-N2O (δ15N-N2O). We observed linear relationships between δ15N-N2O and the logarithmic transformed N2O/(N2+N2O) emission ratios. Through independent measurements, we verified that the undisturbed N2 flux from aquatic ecosystems can be inferred from measurements of N2O emissions and the δ15N-N2O signature. Our method allows the determination of field-scale N2 fluxes from undisturbed aquatic ecosystems, and thereby allows model predictions of denitrification rates to be tested. The undisturbed N2 fluxes observed are almost one order of magnitude higher than those estimated by the traditional method, where perturbation of the system occurs, indicating that the ability of aquatic ecosystems to remove Nr may have been severely underestimated.

  19. Spreading of Oil Spill on Placid Aquatic Medium

    Directory of Open Access Journals (Sweden)

    Derrick O. NJOBUENWU

    2008-06-01

    Full Text Available Continuous research in the development of suitable predictive model is vital as the input of oil spills into the aquatic environment particularly in the Niger Delta area of Nigeria is alarming due to frequent oil spills. This eventually affects aquatic organisms and shoreline activities. This work developed an semi-empirical expression that can predict the horizontal spreading of Niger Delta Oil Spills (NDOS on a placid water body using simple physical coefficients of the oil and the aquatic medium. The empirical expression developed is a function of the spreading coefficient which was derived from heuristic arguments and enhanced to deal with gravity, viscous and surface tension forces. The extent of spread of various oil samples was found to correlate with non-dimensional groups comprised of the ratios of the product between density, viscosity for oil and water respectively. This model provides an easy means to estimate oil slick transport under stagnant water conditions at specific locations in the Niger Delta area. The semi-empirical model is verified against most popular empirical model.

  20. Differences in fatty acid composition between aquatic and terrestrial insects used as food in human nutrition.

    Science.gov (United States)

    Fontaneto, Diego; Tommaseo-Ponzetta, Mila; Galli, Claudio; Risé, Patrizia; Glew, Robert H; Paoletti, Maurizio G

    2011-01-01

    Edible insects may be a source of long-chain polyunsaturated fatty acids (LC-PUFA). The aim of this article is to test for differences in aquatic and terrestrial insects used in human nutrition. We implemented linear models and discovered that differences in the proportion of LC-PUFA between aquatic and terrestrial insects do exist, with terrestrial insects being significantly richer in particular omega-6 fatty acids. In conclusion, any kind of insect may provide valuable sources of LC-PUFA. Because terrestrial insects are more abundant and easier to collect, they can be considered a better source of LC-PUFA than aquatic ones.

  1. The bioaccumulation and effects of selenium in the oligochaete Lumbriculus variegatus via dissolved and dietary exposure routes.

    Science.gov (United States)

    Xie, Lingtian; Wu, Xing; Chen, Hongxing; Luo, Yongju; Guo, Zhongbao; Mu, Jingli; Blankson, Emmanuel R; Dong, Wu; Klerks, Paul L

    2016-09-01

    Aquatic organisms take up selenium from solution and from their diets. Many questions remain regarding the relative importance of selenium accumulation from these sources and resulting effects in benthic invertebrates. The present study addressed the toxicity and accumulation of Se via dissolved and dietary exposures to three different Se species, in the freshwater oligochaete Lumbriculus variegatus. Worms were exposed to 20μg/g dry weight of selenite (Se(IV)), selenate (Se(VI)), or seleno-l-methionine (Se-Met) in their diet (sediment) or to 15μg/L dissolved Se in water-only exposures. While the dissolved and sediment Se levels differed greatly, such levels may co-occur at a Se-contaminated site. Se accumulation, worm population growth, lipid peroxidation (as TBARS), and Na(+)/K(+)-ATPase activity were quantified at the end of the 2-week exposure. The sediment Se-Met exposure caused 100% mortality, while worm densities were reduced by the other exposures except the Se(VI) one. Se bioaccumulation was generally higher for the sediment-Se exposure than the dissolved-Se ones, and was higher for Se(IV) than Se(VI) in the dissolved-Se exposure but not the sediment-Se one. The Se accumulation was highest for Se-Met. The oligochaetes that accumulated Se had higher levels of lipid peroxidation and reduced Na(+)/K(+)-ATPase activity. The present study's findings of differences in Se accumulation and toxicity for the three Se species, with effects generally but not exclusively a function of Se body burdens, underscore the need for research on these issues in invertebrates. Moreover, the results imply that the dietary uptake route is the predominant one for Se accumulation in L. variegatus. PMID:27450235

  2. Wetland management and rice farming strategies to decrease methylmercury bioaccumulation and loads from the Cosumnes River Preserve, California

    Science.gov (United States)

    Eagles-Smith, Collin A.; Ackerman, Joshua T.; Fleck, Jacob; Windham-Myers, Lisamarie; McQuillen, Harry; Heim, Wes

    2014-01-01

    We evaluated mercury (Hg) concentrations in caged fish (deployed for 30 days) and water from agricultural wetland (rice fields), managed wetland, slough, and river habitats in the Cosumnes River Preserve, California. We also implemented experimental hydrological regimes on managed wetlands and post-harvest rice straw management techniques on rice fields in order to evaluate potential Best Management Practices to decrease methylmercury bioaccumulation within wetlands and loads to the Sacramento-San Joaquin River Delta. Total Hg concentrations in caged fish were twice as high in rice fields as in managed wetland, slough, or riverine habitats, including seasonal managed wetlands subjected to identical hydrological regimes. Caged fish Hg concentrations also differed among managed wetland treatments and post-harvest rice straw treatments. Specifically, Hg concentrations in caged fish decreased from inlets to outlets in seasonal managed wetlands with either a single (fall-only) or dual (fall and spring) drawdown and flood-up events, whereas Hg concentrations increased slightly from inlets to outlets in permanent managed wetlands. In rice fields, experimental post-harvest straw management did not decrease Hg concentrations in caged fish. In fact, in fields in which rice straw was chopped and either disked into the soil or baled and removed from the fields, fish Hg concentrations increased from inlets to outlets and were higher than Hg concentrations in fish from rice fields subjected to the more standard post-harvest practice of simply chopping rice straw prior to fall flood-up. Finally, aqueous methylmercury (MeHg) concentrations and export were highly variable, and seasonal trends in particular were often opposite to those of caged fish. Aqueous MeHg concentrations and loads were substantially higher in winter than in summer, whereas caged fish Hg concentrations were relatively low in winter and substantially higher in summer. Together, our results highlight the

  3. FLOW STRUCTURE AND SEDIMENT TRANSPORT WITH IMPACTS OF AQUATIC VEGETATION

    Institute of Scientific and Technical Information of China (English)

    LIU Cheng; SHEN Yong-ming

    2008-01-01

    Aquatic vegetation plays an important role in the flow structure of open channels and thus changes the fate and the transport of sediment. This article proposes a three-dimensional turbulence model by introducing vegetation density and drag force into the control equations of water flow in the presence of vegetation. The model was used to calculate the impacts of submerged vegetation on the vertical profiles of longitudinal flow velocities, the changes of the depth-averaged flow velocities in a compound channel with emergent vegetation in the floodplain, the removal of suspended sediment from the channels by emergent vegetation, and the bed changes around and in a vegetated island. Numerical investigations show that aquatic vegetation retards flow in the vegetation zone, reduces the sediment transport capacity, and contributes to erosion on both sides of the vegetated island. Calculated results agree well with experimental results.

  4. Structural changes in response to bioaccumulation of iron and mercury in Chromolaena odorata (L.) King & Robins.

    Science.gov (United States)

    Swapna, K S; Salim, Nabeesa; Chandra, Ratheesh; Puthur, Jos T

    2015-09-01

    A comparative study was designed to elucidate the effect of iron and mercury on the morphological and anatomical changes as well as bioaccumulation potential in Chromolaena odorata. Plants were grown in half-strength Hoagland nutrient medium artificially contaminated with known quantities of HgCl2 (15 μM) and FeCl3 (1000 μM). Bioaccumulation of Hg and Fe was maximum in the root, and comparatively reduced bioaccumulation was recorded in the stem and leaves. Microscopic studies on morphology and anatomy revealed development of trichomes and lenticels on the stem and modified trichomes on leaves. Localized deposits of stained masses in various internal parts of the root, stem and leaf also were observed. Differential adaptation/strategy of C. odorata to attain tolerance towards Hg and Fe and phytoremediation potential of the plant is discussed. PMID:26239568

  5. Equilibrium Sampling to Determine the Thermodynamic Potential for Bioaccumulation of Persistent Organic Pollutants from Sediment

    DEFF Research Database (Denmark)

    Jahnke, Annika; MacLeod, Matthew; Wickström, Håkan;

    2014-01-01

    Equilibrium partitioning (EqP) theory is currently the most widely used approach for linking sediment pollution by persistent hydrophobic organic chemicals to bioaccumulation. Most applications of the EqP approach assume (I) a generic relationship between organic carbon-normalized chemical...... concentrations in sediments and lipid-normalized concentrations in biota and (II) that bioaccumulation does not induce levels exceeding those expected from equilibrium partitioning. Here, we demonstrate that assumption I can be obviated by equilibrating a silicone sampler with chemicals in sediment, measuring...... chemical concentrations in the silicone, and applying lipid/silicone partition ratios to yield concentrations in lipid at thermodynamic equilibrium with the sediment (CLip⇌Sed). Furthermore, we evaluated the validity of assumption II by comparing CLip⇌Sed of selected persistent, bioaccumulative and toxic...

  6. Bioaccumulation and food chain transfer of corrosion products from radioactive stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Young, J.S.

    1986-07-01

    Two sets of experiments were conducted to determine if corrosion products from radioactive Type 347 stainless steel could be biologically transferred from sediment through a marine food chain, and whether corrosion products dissolved in seawater could be bioaccumulated and then eliminated. Corrosion products containing /sup 60/Co and /sup 63/Ni from the radioactive stainless steel were introduced into marine sediments. Infaunal polychaete worms exposed to these sediments bioaccumulated the radionuclides. The feeding of these worms to shrimp and fish resulted in a trophic transfer of the radioactive products across a one-step food chain. The magnitude of the transfers are described in terms of transfer factors. Dissolved corrosion products as measured by the radionuclides were also bioaccumulated by shrimp and fish concentrating more than fish. Concentration factors were calculated.

  7. Optimal choice of pH for toxicity and bioaccumulation studies of ionizing organic chemicals

    DEFF Research Database (Denmark)

    Rendal, Cecilie; Kusk, Kresten Ole; Trapp, Stefan

    2011-01-01

    at multiple pH levels. Toxicity and bioconcentration factors (BCFs) were higher for acids at lower pH values, whereas the opposite was true for bases. The effect of pH was most pronounced when pH-pKa was in the range of -1 to 3 for acids, and -3 to 1 for bases. The factor by which toxicity and BCF changed......It is recognized that the pH of exposure solutions can influence the toxicity and bioaccumulation of ionizing compounds. The present study investigates whether it can be considered a general rule that an ionizable compound is more toxic and more bioaccumulative when in the neutral state. Three...... processes were identified to explain the behavior of ionizing compounds with changing pH: the change in lipophilicity when a neutral compound becomes ionized, electrical attraction, and the ion trap. The literature was screened for bioaccumulation and toxicity tests of ionizing organic compounds performed...

  8. Bioaccumulation and food chain transfer of corrosion products from radioactive stainless steel

    International Nuclear Information System (INIS)

    Two sets of experiments were conducted to determine if corrosion products from radioactive Type 347 stainless steel could be biologically transferred from sediment through a marine food chain, and whether corrosion products dissolved in seawater could be bioaccumulated and then eliminated. Corrosion products containing 60Co and 63Ni from the radioactive stainless steel were introduced into marine sediments. Infaunal polychaete worms exposed to these sediments bioaccumulated the radionuclides. The feeding of these worms to shrimp and fish resulted in a trophic transfer of the radioactive products across a one-step food chain. The magnitude of the transfers are described in terms of transfer factors. Dissolved corrosion products as measured by the radionuclides were also bioaccumulated by shrimp and fish concentrating more than fish. Concentration factors were cal