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Sample records for affect aquatic organisms

  1. Irrigation agriculture affects organic matter decomposition in semi-arid terrestrial and aquatic ecosystems.

    PubMed

    Arroita, Maite; Causapé, Jesús; Comín, Francisco A; Díez, Joserra; Jimenez, Juan José; Lacarta, Juan; Lorente, Carmen; Merchán, Daniel; Muñiz, Selene; Navarro, Enrique; Val, Jonatan; Elosegi, Arturo

    2013-12-15

    Many dryland areas are being converted into intensively managed irrigation crops, what can disrupt the hydrological regime, degrade soil and water quality, enhance siltation, erosion and bank instability, and affect biological communities. Still, the impacts of irrigation schemes on the functioning of terrestrial and aquatic ecosystems are poorly understood. Here we assess the effects of irrigation agriculture on breakdown of coarse organic matter in soil and water. We measured breakdown rates of alder and holm oak leaves, and of poplar sticks in terrestrial and aquatic sites following a gradient of increasing irrigation agriculture in a semi-arid Mediterranean basin transformed into irrigation agriculture in 50% of its surface. Spatial patterns of stick breakdown paralleled those of leaf breakdown. In soil, stick breakdown rates were extremely low in non-irrigated sites (0.0001-0.0003 day(-1)), and increased with the intensity of agriculture (0.0018-0.0044 day(-1)). In water, stick breakdown rates ranged from 0.0005 to 0.001 day(-1), and increased with the area of the basin subject to irrigation agriculture. Results showed that irrigation agriculture affects functioning of both terrestrial and aquatic ecosystems, accelerating decomposition of organic matter, especially in soil. These changes can have important consequences for global carbon budgets.

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

    PubMed

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

    2015-04-21

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

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

    EPA Science Inventory

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

  4. Chapter 6: Selenium Toxicity to Aquatic Organisms

    EPA Science Inventory

    This chapter addresses the characteristics and nature of organic selenium (Se) toxicity to aquatic organisms, based on the most current state of scientific knowledge. As such, the information contained in this chapter relates to the 'toxicity assessment' phase of aquatic ecologi...

  5. Apparatus Induces And Fixes Small Aquatic Organisms

    NASA Technical Reports Server (NTRS)

    Todd, Christopher

    1992-01-01

    Syringe-and-bag assembly compact, lightweight self-contained, portable apparatus introducing liquids to aquatic organisms. Isolates organisms from toxic substances until time of introduction. Includes plastic syringes, each containing inner, sealed, burstable bag. Adaptable to use in biological tests and experiments at remote locations on Earth.

  6. SEDIMENT ASSOCIATED PHOTOTOXICITY TO AQUATIC ORGANISMS

    EPA Science Inventory

    Phototoxicity is a two to greater than 1000-fold increase in chemical toxicity caused by ultraviolet radation (UV), which has been demonstrated in a broad range of marine and freshwater fish, invertebrates, and other aquatic organisms in water column exposures. Field collected s...

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

    PubMed

    Katagi, Toshiyuki

    2010-01-01

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

  8. Impact of Organic Contamination on Some Aquatic Organisms

    PubMed Central

    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

  9. Effects of the antihistamine diphenhydramine on selected aquatic organisms.

    PubMed

    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.

  10. Effects of triclosan on various aquatic organisms.

    PubMed

    Tatarazako, Norihisa; Ishibashi, Hiroshi; Teshima, Kenji; Kishi, Katsuyuki; Arizono, Koji

    2004-01-01

    Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) is widely used as an antibacterial agent in various industrial products, such as textile goods, soap, shampoo, liquid toothpaste and cosmetics, and often detected in wastewater effluent. However, there is a paucity of data on the toxicity of triclosan and its effects on aquatic organisms. In this study, the acute toxicity of triclosan to the Microtox bacterium (Vibrio fischeri), a microalga (Selenastrum capricornutum), a crustacean (Ceriodaphnia dubia) and fish (Danio rerio and Oryzias latipes) was examined. As a result, the MicrotoxR bacterium, crustacean and fish had similar sensitivities towards triclosan toxicity (i.e., IC25 from 0.07 to 0.29 mg/L triclosan). In contrast, the microalga was about 30-80-fold (IC25 = 0.0034 mg/L triclosan) more sensitive to triclosan toxicity than the bacterium and fish. Therefore, triclosan is quite highly toxic to aquatic animals, and is particularly highly toxic to the green alga used as a test organism in this study. This result indicates that triclosan exerts a marked influence on algae, which are important organisms being the first-step producers in the ecosystem; therefore, the possible destruction of the balance of the ecosystem is expected if triclosan is discharged into the environment at high levels.

  11. An Investigation into the Physico-chemical Factors Affecting the Abundance and Diversity of Aquatic Insects in Organically Manured Aquadams and Their Utilization by Oreochromis mossambicus (Perciformes: Cichlidae).

    PubMed

    Rapatsa, M M; Moyo, N A G

    2015-08-01

    The interaction between the fish Oreochromis mossambicus (Percifomes: Cichlidae) and aquatic insects after application of chicken, cow, and pig manure was studied in 7,000-liter plastic aquadams. Principal component analysis showed that most of the variation in water quality after application of manure was accounted for by potassium, nitrogen, dissolved oxygen, phosphate, and alkalinity. Canonical correspondence analysis showed that Gyrinidae, Elminidae, Hydrophilidae, Hydraenidae, and Athericidae were associated with high nutrient levels (nitrogen, phosphorus, and potassium) characteristic of the chicken manure. However, the most abundant aquatic insects Gerridae, Notonectidae, and Culicidae were close to the centre of the ordination and not defined by any nutrient gradient. The Shannon-Wiener diversity was highest in the aquadams treated with chicken manure. The most frequently occurring aquatic insects in the diet of O. mossambicus were culicid mosquitoes in all the treatments. However, in the laboratory, Chironomidae were the most preferred because they lacked refuge. Notonectidae and Gerridae were not recorded in the diet of O. mossambicus despite their abundance. This may be because of their anti-predation strategies. Laboratory experiments showed that Notonectidae, Gyrinidae, and Gerridae fed on Chironomidae and Culicidae. This implies that aquatic predatory insects competed for food with O. mossambicus.

  12. The multixenobiotic resistance mechanism in aquatic organisms

    SciTech Connect

    Kurelec, B. )

    1992-01-01

    Many aquatic organisms thrive and reproduce in polluted waters. This fact indicates that they are well equipped with a defense system(s) against several toxic xenobiotics simultaneously because water pollution is typically caused by a mixture of a number of pollutants. We have found that the biochemical mechanism underlying such multixenobiotic' resistance in freshwater and marine mussel, in several marine sponges, and in freshwater fish is similar to the mechanism of multidrug resistance (MDR) found in tumor cells that became refractory to treatment with a variety of chemotherapeutic agents. All these organisms possess a verapamil-sensitive potential to bind 2-acetylaminofluorene and vincristine onto membrane vesicles. They all express mRNA for mdr1 gene, and mdr1 protein product, the glycoprotein P170. Finally, in in vivo experiments, the accumulation of xenobiotics is enhanced in all investigated organisms in the presence of verapamil, the inhibitor of the P170 extrusion pump. The knowledge that the presence of one xenobiotic may block the pumping out, and hence accelerating accumulation, of others, may help us to understand and interpret our present and past data on different environmental parameters obtained using indicator organisms.99 references.

  13. Pesticide toxicity index for freshwater aquatic organisms

    USGS Publications Warehouse

    Munn, Mark D.; Gilliom, Robert J.

    2001-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  16. Life under solar UV radiation in aquatic organisms

    NASA Astrophysics Data System (ADS)

    Sinha, R. P.; Häder, D.-P.

    Aquatic photosynthetic organisms are exposed to solar ultraviolet (UV) radiation while they harvest longer wavelength radiation for energetic reasons. Solar UV-B radiation (280 - 315 nm) affects motility and orientation in motile organisms and impairs photosynthesis in cyanobacteria, phytoplankton and macroalgae as measured by monitoring oxygen production or pulse amplitude modulated fluorescence analysis. Upon moderate UV stress most organisms respond by photoinhibition which is an active downregulation of the photosynthetic electron transport in photosystem II by degradation of UV-damaged D1 protein. Photoinhibition is readily reversible during recovery in shaded conditions. Excessive UV stress causes photodamage which is not easily reversible. Another major target is the DNA where UV-B mainly induces thymine dimers. Cyanobacteria, phytoplankton and macroalgae produce scytonemin, mycosporine-like amino acids and other UV-absorbing substances to protect themselves from short wavelength solar radiation.

  17. Active Pharmaceutical Ingredients and Aquatic Organisms

    EPA Science Inventory

    The presence of active pharmaceuticals ingredients (APIs) in aquatic systems in recent years has led to a burgeoning literature examining environmental occurrence, fate, effects, risk assessment, and treatability of these compounds. Although APIs have received much attention as ...

  18. Effects of Exposure to Semiconductor Nanoparticles on Aquatic Organisms

    PubMed Central

    Leigh, Kenton; Bouldin, Jennifer; Buchanan, Roger

    2012-01-01

    Because of their unique physical, optical, and mechanical properties, nanomaterials hold great promise in improving on a wide variety of current technologies. Consequently, their use in research and consumer products is increasing rapidly, and contamination of the environment with various nanomaterials seems inevitable. Because surface waters receive pollutants and contaminants from many sources including nanoparticles and act as reservoirs and conduits for many environmental contaminants, understanding the potential impacts of nanoparticles on the organisms within these environments is critical to evaluating their potential toxicity. While there is much to be learned about interactions between nanomaterials and aquatic systems, there have been a number of recent reports of interactions of quantum dots (QDs) with aquatic environments and aquatic organisms. This review is focused on providing a summary of recent work investigating the impacts of quantum dots on aquatic organisms. PMID:22131989

  19. Toxicity of trifluoroacetate to aquatic organisms

    SciTech Connect

    Berends, A.G.; Rooij, C.G. de; Boutonnet, J.C.; Thompson, R.S.

    1999-05-01

    As a result of the atmospheric degradation of several hydrofluorocarbons and hydrochlorofluorocarbons, trifluoroacetate (TFA) will be formed. Through precipitation, TFA will enter aquatic ecosystems. To evaluate the impact on the aquatic environment, an aquatic toxicity testing program was carried out with sodium trifluoroacetate (NaTFA). During acute toxicity tests, no effects of NaTFA on water fleas (Daphnia magna) and zebra fish (Danio retrio) were found at a concentration of 1,200 mg/L. A 7-d study with duckweed (Lemna gibba Ge) revealed a NOEC of 300 mg/L. On the basis of the results of five toxicity tests with Selenastrum capricornutum, they determined a NOEC of 0.12 mg/L. However, algal toxicity tests with NaTFA and Chlorella vulgaris, Scenedesmus subspicatus, Chlamydomonas reinhardtii, Dunaliella tertiolecta, Eugelan gracilis, Phaeodactylum tricornutum, Navicula pelliculosa, Skeletonema costatum, Anabaena flos-aquae, and Microcystis aeruginosa resulted in EC50 values that were all higher than 100 mg/L. The toxicity of TFA to S. capricornutum could be due to metabolic defluorination to monofluoroacetate (MFA), which is known to inhibit the citric acid cycle. A toxicity test with MFA and S. capricornutum revealed it to be about three orders of magnitude more toxic than TFA. However, a bioactivation study revealed that defluorination of TFA was less than 4%. On the other hand, S. capricornutum exposed to a toxic concentration of NaTFA showed a recovery of growth when citric acid was added, suggesting that TFA (or a metabolite of TFA) interferes with the citric acid cycle. A recovery of the growth of S. capricornutum was also found when TFA was removed from the test solutions. Therefore, TFA should be considered algistatic and not algicidic for S. capricornutum. On the basis of the combined results of the laboratory tests and a previously reported semi-field study, they can consider a TFA concentration of 0.10 mg/L as safe for the aquatic ecosystem.

  20. The effects of ionizing radiation on aquatic organisms

    SciTech Connect

    Templeton, W.L.; Blaylock, B.G.

    1990-09-01

    Scientific Committee {number sign}64-6 of the National Council on Radiation Protection (NCRP) of the United States has recently completed a review of the literature on the effects of ionizing radiation on aquatic organisms (NCRP 1990). In this report, the NCRP provides guidance for a dose rate below which deleterious effects to aquatic organisms are acceptably low; reviews a series of simple dosimetric models that can be applied to demonstrate compliance with such a dose rate; provides examples of the application of the models to contaminated aquatic environments; and evaluates the validity of the statement of the International Commission on Radiation Protection (ICRP 1977) that if man is adequately protected then other living things are also likely to be sufficiently protected.'' 6 refs.

  1. Partition of nonionic organic compounds in aquatic systems

    USGS Publications Warehouse

    Smith, James A.; Witkowski, Patrick J.; Chiou, Cary T.

    1988-01-01

    In aqueous systems, the distribution of many nonionic organic solutes in soil-sediment, aquatic organisms, and dissolved organic matter can be explained in terms of a partition model. The nonionic organic solute is distributed between water and different organic phases that behave as bulk solvents. Factors such as polarity, composition, and molecular size of the solute and organic phase determine the relative importance of partition to the environmental distribution of the solute. This chapter reviews these factors in the context of a partition model and also examines several environmental applications of the partition model for surface- and ground-water systems.

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

    PubMed Central

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

    2016-01-01

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

  3. BIOGEOCHEMISTRY OF CHLORINATED ORGANIC CONTAMINANTS IN AQUATIC ECOSYSTEMS

    EPA Science Inventory

    Over the last several years we have conducted both laboratory and field studies to develop a better understanding of the movement of chlorinated organic compounds through aquatic ecosystems, with special emphasis on the differential movement of these compounds due to physical/che...

  4. Organic Geochemistry and Sources of Natural Aquatic Foams

    USGS Publications Warehouse

    Mills, M.S.; Thurman, E.M.; Ertel, J.; Thorn, K.A.

    1996-01-01

    Aquatic foams and stream-water samples were collected from two pristine sites for humic substances isolation and characterization. Biomarker compounds identified in foam and stream humic substances included phospholipid fatty acids, steroids, and lignin. Results showed that foams had a 10 to 20 fold greater DOC concentration and were enriched in humic substances (90% by weight of DOC) that showed increased hydrophobicity, aliphatic character, and compositional complexity compared to host stream humic substances (55 to 81% by weight of DOC). Foam humic substances also were enriched in humic acid (36 to 83% by weight) compared to host stream humic substances (10 to 14% by weight). Biomarkers, which contributed less than 5% by weight to the DOC pool, indicated higher plants, bacteria, algae, fungi, and diatoms as DOC sources. It is proposed that aquatic foams may be important media for the concentration and transport of organic substances in the aquatic environment.

  5. Peer reviewed: Characterizing aquatic dissolved organic matter

    USGS Publications Warehouse

    Leenheer, Jerry A.; Croué, Jean-Philippe

    2003-01-01

    Whether it causes aesthetic concerns such as color, taste, and odor; leads to the binding and transport of organic and inorganic contaminants; produces undesirable disinfection byproducts; provides sources and sinks for carbon; or mediates photochemical processes, the nature and properties of dissolved organic matter (DOM) in water are topics of significant environmental interest. DOM is also a major reactant in and product of biogeochemical processes in which the material serves as a carbon and energy source for biota and controls levels of dissolved oxygen, nitrogen, phosphorus, sulfur, numerous trace metals, and acidity.

  6. Global warming and environmental contaminants in aquatic organisms: the need of the etho-toxicology approach.

    PubMed

    Manciocco, Arianna; Calamandrei, Gemma; Alleva, Enrico

    2014-04-01

    Environmental contaminants are associated with a wide spectrum of pathological effects. Temperature increase affects ambient distribution and toxicity of these chemicals in the water environment, representing a potentially emerging problem for aquatic species with short-, medium- and long-term repercussions on human health through the food chain. We assessed peer-reviewed literature, including primary studies, review articles and organizational reports available. We focused on studies concerning toxicity of environmental pollutants within a global warming scenario. Existing knowledge on the effects that the increase of water temperature in a contaminated situation has on physiological mechanisms of aquatic organisms is presented. Altogether we consider the potential consequences for the human beings due to fish and shellfish consumption. Finally, we propose an etho-toxicological approach to study the effects of toxicants in conditions of thermal increase, using aquatic organisms as experimental models under laboratory controlled conditions.

  7. A Source of Terrestrial Organic Carbon to Investigate the Browning of Aquatic Ecosystems

    PubMed Central

    Lennon, Jay T.; Hamilton, Stephen K.; Muscarella, Mario E.; Grandy, A. Stuart; Wickings, Kyle; Jones, Stuart E.

    2013-01-01

    There is growing evidence that terrestrial ecosystems are exporting more dissolved organic carbon (DOC) to aquatic ecosystems than they did just a few decades ago. This “browning” phenomenon will alter the chemistry, physics, and biology of inland water bodies in complex and difficult-to-predict ways. Experiments provide an opportunity to elucidate how browning will affect the stability and functioning of aquatic ecosystems. However, it is challenging to obtain sources of DOC that can be used for manipulations at ecologically relevant scales. In this study, we evaluated a commercially available source of humic substances (“Super Hume”) as an analog for natural sources of terrestrial DOC. Based on chemical characterizations, comparative surveys, and whole-ecosystem manipulations, we found that the physical and chemical properties of Super Hume are similar to those of natural DOC in aquatic and terrestrial ecosystems. For example, Super Hume attenuated solar radiation in ways that will not only influence the physiology of aquatic taxa but also the metabolism of entire ecosystems. Based on its chemical properties (high lignin content, high quinone content, and low C:N and C:P ratios), Super Hume is a fairly recalcitrant, low-quality resource for aquatic consumers. Nevertheless, we demonstrate that Super Hume can subsidize aquatic food webs through 1) the uptake of dissolved organic constituents by microorganisms, and 2) the consumption of particulate fractions by larger organisms (i.e., Daphnia). After discussing some of the caveats of Super Hume, we conclude that commercial sources of humic substances can be used to help address pressing ecological questions concerning the increased export of terrestrial DOC to aquatic ecosystems. PMID:24124511

  8. Emerging aquatic insects affect riparian spider distribution and growth rates in a temperate rainforest

    NASA Astrophysics Data System (ADS)

    Marczak, L. B.; Richardson, J. S.

    2005-05-01

    Emerging aquatic insects from streams provide a temporally shifting, alternative source of energy to riparian web-building spiders. The effects of dynamics in aquatic insect emergence on spider distributions are poorly understood. We manipulated the abundance of aquatic insects in riparian forests of British Columbia by excluding aquatic insects using a greenhouse type covering from May through the end of July. In the absence of manipulations, aquatic insect abundance generally peaks in July. The overall density of riparian spiders was reduced when aquatic insects were excluded in May and July but not in June. As in similar studies, tetragnathid spiders in particular showed a strong response to aquatic insect exclusion. The ideal free distribution predicts that organisms at low densities should have equal access to resources for growth to those at high densities. Using comparisons of body size low and high densities of animals we determined that tetragnathid abundance and growth patterns do represent an ideal free distribution.

  9. Toxicity of ferric chloride sludge to aquatic organisms.

    PubMed

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

    2007-06-01

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

  10. Biogeochemical interactions affecting hepatic trace element levels in aquatic birds

    SciTech Connect

    Moeller, G.

    1996-07-01

    Knowledge of elemental interactions is important to the toxicological assessment of wildlife in the geochemical environment. This study determines the concentrations of Al, As, B, Ba, Be, Cd, Cr, Cu, Fe, Pb, Li, Mg, Mn, Hg, Mo, Ni, Se, Ag, V, and Zn in aquatic bird liver, fish liver, whole bivalves, insects, and waters in several aquatic ecosystems in northern California. There is evidence of strong in vivo and environmental interactions, including the observation of manganese as a possible cofactor or indicator in selenium bioaccumulation. The nearest neighbor selenium correlation in aquatic bird liver tissue that results from this work is Cd-Mn-Se-Hg-As. The correlation of liver selenium to manganese in vivo and the result that the majority of the variance in liver selenium concentration is contained in the manganese term of the regression model relating Se to Cd, Mn, and Hg is new knowledge in the study of aquatic birds. A linear relationship between liver selenium and environmental manganese (water and sediment) is found in the data, suggesting a water chemistry compartmentalization or activation of toxicants. Alternatively, the hepatic concentrations of selenium, manganese, and iron suggest induction of enzymes in response to oxidative stress.

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

    PubMed

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

    2015-02-01

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

  12. Aquatic Organic Matter Fluorescence - from phenomenon to application

    NASA Astrophysics Data System (ADS)

    Reynolds, Darren

    2014-05-01

    The use of fluorescence to quantify and characterise aquatic organic matter in river, ocean, ground water and drinking and waste waters has come along way since its discovery as a phenomenon in the early 20th century. For example, there are over 100 papers published each year in international peer reviewed journals, an order of magnitude increase since a decade ago (see Figure taken from ISI database from 1989 to 2007 for publications in the fields of river water and waste water). Since then it has been extensively used as a research tool since the 1990's by scientists and is currently used for a wide variety of applications within a number of sectors. Universities, organisations and companies that research into aquatic organic matter have either recently readily use appropriate fluorescence based techniques and instrumentation. In industry and government, the technology is being taken up by environmental regulators and water and wastewater companies. This keynote presentation will give an overview of aquatic organic matter fluorescence from its conception as a phenomenon through to its current use in a variety of emerging applications within the sectors concerned with understanding, managing and monitoring the aquatic environment. About the Speaker Darren Reynolds pioneered the use of fluorescence spectroscopy for the analysis of wastewaters in the 1990's. He currently leads a research group within the Centre for Research in Biosciences and sits on the Scientific Advisory Board for the Institute of Bio-Sensing Technology at the University of the West of England, Bristol. He is a multidisciplinary scientist concerned with the development of technology platforms for applications in the fields of environment/agri-food and health. His current research interests include the development of optical technologies and techniques for environmental and biological sensing and bio-prospecting applications. He is currently involved in the development and use of synthetic biology

  13. The aquatic impact of ionic liquids on freshwater organisms.

    PubMed

    Costa, Susana P F; Pinto, Paula C A G; Saraiva, M Lúcia M F S; Rocha, Fábio R P; Santos, Joyce R P; Monteiro, Regina T R

    2015-11-01

    Ionic liquids (ILs), also known as liquid electrolytes, are powerful solvents with a wide variety of academic and industrial applications. Bioassays with aquatic organisms constitute an effective tool for the evaluation of ILs' toxicity, as well as for the prediction and identification of possible moieties that act as toxicophores. In this work, the acute toxicity of six ILs and two commonly used organic solvents was evaluated using freshwater organisms: Daphnia magna, Raphidocelis subcapitata and Hydra attenuata. The bioassays were performed by exposing the organisms to increasing concentrations of the ILs and observing D. magna immobilization, R. subcapitata growth inhibition, and the morphological or mortality effects in H. attenuata. The results demonstrate that the tested organisms are not equally susceptible to the ILs, e.g., bmpyr [BF4] was the least toxic compound for R. subcapitata, N1,1 [N1,1,1OOH] for D. magna and emim [Tf2N] for H. attenuata. This highlights the importance of applying a battery of assays in toxicological analysis. Additionally, Hydra proved to be the most tolerant species to the tested ILs. According to their hazard rankings, the tested ILs are considered practically harmless or moderately toxic, except (Hex)3(TDec)P [Cl], which was classified as highly toxic. The ILs were revealed to be more harmful to aquatic systems than the tested organic solvents, reaffirming the need to analyze carefully the (eco)toxicological impact of these compounds. The present study provides additional data in the evaluation of the potential hazard and the impact of ILs in the environment.

  14. Relative sensitivity of some selected aquatic organisms to phenol

    SciTech Connect

    Tisler, T.; Zagorc-Koncan, J.

    1995-05-01

    Although the possibility of adverse effects of materials on organisms was recognized earlier, not until the 1940s or 1950s short-term acute tests with fishes were being studied. The fishes have become the most popular test organism because the effects of toxic substances in streams have been most evident on the fishes. Many other organisms bearing the important role in the environment live in the waters and began to be used in the toxicological research. Nowadays such great variety of test methods and organisms make the selection of the suitable toxicity test difficult. One or two species of test organisms only are often applied in the determination of the toxic substances or wastewaters. The toxicity test with daphnids is widely used due to its sensitivity to the great part of toxic substances. The purpose of our research was to determine the toxicity of phenol to some aquatic organisms from the group of bacteria, algae, crustacea and fishes, and to determine the most sensitive kind. Test organisms have been selected from three basic groups in the food chain (bacteria - decomposers, algae - producers and crustacea, fish - consumers). Phenol, an organic degradable substance that is a frequent contaminant in wastewaters, has been chosen for the test substance. 29 refs., 3 tabs.

  15. 40 CFR 158.243 - Experimental use permit data requirements for terrestrial and aquatic nontarget organisms.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... toxicity R R R NR NR NR TGAI, TEP 1, 2, 5, 6, 11 850.1010 Acute toxicity freshwater invertebrates R R R NR NR NR TGAI, TEP 1, 2, 6, 7, 11 850.1300 Aquatic invertebrate life cycle (freshwater) NR R R NR NR NR... aquatic organisms. 7. Data are required on one freshwater aquatic invertebrate species. 8. Data...

  16. 40 CFR 158.243 - Experimental use permit data requirements for terrestrial and aquatic nontarget organisms.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... toxicity R R R NR NR NR TGAI, TEP 1, 2, 5, 6, 11 850.1010 Acute toxicity freshwater invertebrates R R R NR NR NR TGAI, TEP 1, 2, 6, 7, 11 850.1300 Aquatic invertebrate life cycle (freshwater) NR R R NR NR NR... aquatic organisms. 7. Data are required on one freshwater aquatic invertebrate species. 8. Data...

  17. 40 CFR 158.243 - Experimental use permit data requirements for terrestrial and aquatic nontarget organisms.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... toxicity R R R NR NR NR TGAI, TEP 1, 2, 5, 6, 11 850.1010 Acute toxicity freshwater invertebrates R R R NR NR NR TGAI, TEP 1, 2, 6, 7, 11 850.1300 Aquatic invertebrate life cycle (freshwater) NR R R NR NR NR... aquatic organisms. 7. Data are required on one freshwater aquatic invertebrate species. 8. Data...

  18. Effects of water temperature on the toxicity of chemicals to aquatic organisms

    SciTech Connect

    Mayer, F.; Brecken-Folse, J.; Howe, G.; Linton, T.

    1995-12-31

    Water temperatures fluctuate regularly in aquatic environments, producing physiological and ecological changes in resident biota. Temperature has been recognized as a critical factor affecting the toxicity of chemicals by altering the physiological condition of the biota and the interactions between organisms and toxicants. Temperature significantly affects respiration rates, chemical absorption, and chemical detoxification and excretion. Acute toxicity of most chemicals to aquatic organisms is positively correlated with temperature; however, the toxicity of some chemicals is negatively correlated with or not affected by temperature. Regression slopes of toxicity appear consistent among species within a chemical for temperature, indicating chemical rather than biological differences in toxicity. Temperature may not affect acute toxicity per se, but does affect bioavailability and, therefore, exposure. Octanol/water partition coefficients are altered by temperature and could replace some biological testing since the partition coefficient-acute toxicity relationship has been well established. Temperature may only alter the rate of intoxication in chronic exposures no-effect concentrations do not appear to be affected by temperature; only the time required to attain the same no-effect concentration varies.

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

    USGS Publications Warehouse

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

    2006-01-01

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

  20. Model simulation of atrazine exposure to aquatic nontarget organisms

    SciTech Connect

    Williams, W.M.; Cheplick, J.M.; Balu, K.

    1996-10-01

    Pesticide fate and transport models have been identified by a number of regulatory work groups, including the Aquatic Risk Assessment and Mitigation Dialogue Group (ARAMDG) and the FIFRA Exposure Modeling Work Group (EMWG), as potential valuable tools in improving regulatory decisions for pesticide registration. To date, models uses have been limited to preliminary screening evaluations because the predictive capabilities of candidate models have not been adequately characterized and because procedures for scenario identification have not been tested. This paper presents an overview of a comprehensive modeling study that was conducted to evaluate exposure concentrations of atrazine to nontarget organisms and their ecosystems that may result from usage patterns of the herbicide throughout the United States. Simulations were conducted using the Pesticide Root Zone Model (PRZM-2.3) and the Riverine Environments Water Quality Model (RIVWQ-2.0). Included are procedures used for scenario identification, model comparisons to field runoff and aquatic monitoring studies, and the statistical compilation of results for risk assessment use.

  1. Research of nickel nanoparticles toxicity with use of Aquatic Organisms

    NASA Astrophysics Data System (ADS)

    Morgaleva, T.; Morgalev, Yu; Gosteva, I.; Morgalev, S.

    2015-11-01

    The effect of nanoparticles with the particle size Δ50=5 nm on the test function of aquatic organisms was analyzed by means of biotesting methods with the use of a complex of test-organisms representing general trophic levels. The dependence of an infusoria Paramecium caudatum chemoattractant-elicited response, unicellular algae Chlorella vulgaris Beijer growth rate, Daphnia magna Straus mortality and trophic activity and Danio rerio fish kill due to nNi disperse system concentration, is estimated. It is determined that the release of chlorella into cultivated environment including nNi as a feed for daphnias raises the death rate of entomostracans. The minimal concentration, whereby an organism response to the effect of nNi is registered, depends on the type of test organism and the analysed test function. L(E)C20 is determined for all the organisms used in bioassays. L(E)C50 is estimated for Paramecium caudatum (L(E)C50 = 0.0049 mg/l), for Chlorella vulgaris Beijer (L(E)C50 = 0.529 mg/l), for Daphnia m. S (L(E)C50 > 100 mg/l) and for fish Danio rerio (L(E)C50 > 100 mg/l). According to the Globally Harmonized System hazard substance evaluation criteria and Commission Directive 93/67/EEC, nNi belongs to the “acute toxicity 1” category of toxic substances.

  2. Organic volatile sulfur compounds in inland aquatic systems

    SciTech Connect

    Richards, S.R.

    1991-01-01

    The speciation, concentration, and fluxes of organic volatile sulfur compounds (VSCs) in a wide variety of inland aquatic systems wee studied. Dissolved VSCs were sparged from water samples, trapped cryogenically, and quantified by gas chromatograph equipped with a flame photometric detector. Species detected and mean surface water concentrations were: carbonyl sulfide (COS), 0.091-7.6 nM; methanethiol (MSH), undetected-180 nM; dimethyl sulfide (DMS), 0.48-1290 nM; carbon disulfide (CS[sub 2]), undetected-69 nM; dimethyl disulfide (DMDS), undetected-68 nM. The range in surface water concentrations of over five orders of magnitude was influenced principally by lake depth and sulfate concentration ([SO[sub 4][sup 2[minus

  3. Toxicity of a complex munitions wastewater to aquatic organisms

    SciTech Connect

    Liu, D.H.W.; Bailey, H.C.; Pearson, J.G.

    1981-10-01

    The toxicity to freshwater organisms of a complex munitions effluent called condensate wastewater was determined using a novel and relatively economical approach proposed by Pearson and co-workers at the Second Annual ASTM Symposium on Aquatic Toxicology. Applicable only to complex wastewaters in which the concentrations of the individual chemical components are relatively constant over time, the approach emphasizes performing toxicity and related tests on a chemical mixture representative of the actual wastewater, with secondary attention being directed toward testing the individual chemical components, which is the conventional approach. The testing program comprised several series of static acute toxicity tests on authentic wastewater, artificial wastewater, and selected components to identify the conditions under which they are most toxic and to identify the most sensitive species; a series of flow-through acute toxicity tests on the artificial wastewater using the most sensitive species; a series of short-term bioconcentration tests; several early life-stage tests; and, finally, several life-cycle chronic tests. Twelve species representing three trophic levels were employed in the program. It was concluded that the approach economically and rapidly provided a sufficient data base for assessing the effects of the wastewater on aquatic life. Two modifications were recommended to decrease the cost and time of obtaining the data. One was to perform a static and a flow-through test early in the testing program to identify the most appropriate exposure condition to use in the initial portion of the program. The other was to compute the octanol-water partition coefficients of the organic components of the wastewater before performing any bioconcentration test and to use the coefficients to determine if bioconcentration tests are necessary.

  4. Pressure of non-professional use of pesticides on operators, aquatic organisms and bees in Belgium.

    PubMed

    Fevery, Davina; Houbraken, Michael; Spanoghe, Pieter

    2016-04-15

    Various studies focus on professional pesticide use, whereas pressure of non-professional use on human and the environment is often neglected. In this study, an attempt was made to estimate the pressure of non-professional use of pesticides on operators, aquatic organisms and bees in Belgium based on sales figures and by using three exposure models. A classification in non-professional use was made based on type of pesticide, application method and on intensity of non-professional use. Pressure of non-professional use on operators is highest for intensive operators, caused by the use of insecticides in an aerosol spray can. Pressure of non-professional pesticides on aquatic life is mainly generated by the use of herbicides. The aerosol spray induces the highest pressure whereas the trigger application hardly affects operator and environmental exposure. The ordinary non-professional user generates most pressure on aquatic organisms. Pressure of non-professional pesticides on bees is mainly caused by the use of insecticides, especially the active substance imidacloprid in combination with the aerosol spray can application method applied by an intensive operator. In general, both total usage (kg) and pressure of pesticides decreased for the period 2005 to 2012 due to efforts made by the government and industry. The results of this study suggest to pay special attention to aerosol spray applications and the non-professional use of insecticides.

  5. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Fish, crustaceans, mollusks, and other... § 230.31 Fish, crustaceans, mollusks, and other aquatic organisms in the food web. (a) Aquatic organisms in the food web include, but are not limited to, finfish, crustaceans, mollusks, insects,...

  6. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Fish, crustaceans, mollusks, and other... § 230.31 Fish, crustaceans, mollusks, and other aquatic organisms in the food web. (a) Aquatic organisms in the food web include, but are not limited to, finfish, crustaceans, mollusks, insects,...

  7. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Fish, crustaceans, mollusks, and other... § 230.31 Fish, crustaceans, mollusks, and other aquatic organisms in the food web. (a) Aquatic organisms in the food web include, but are not limited to, finfish, crustaceans, mollusks, insects,...

  8. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Fish, crustaceans, mollusks, and other... § 230.31 Fish, crustaceans, mollusks, and other aquatic organisms in the food web. (a) Aquatic organisms in the food web include, but are not limited to, finfish, crustaceans, mollusks, insects,...

  9. Increases in terrestrially derived carbon stimulate organic carbon processing and CO₂ emissions in boreal aquatic ecosystems.

    PubMed

    Lapierre, Jean-François; Guillemette, François; Berggren, Martin; del Giorgio, Paul A

    2013-01-01

    The concentrations of terrestrially derived dissolved organic carbon have been increasing throughout northern aquatic ecosystems in recent decades, but whether these shifts have an impact on aquatic carbon emissions at the continental scale depends on the potential for this terrestrial carbon to be converted into carbon dioxide. Here, via the analysis of hundreds of boreal lakes, rivers and wetlands in Canada, we show that, contrary to conventional assumptions, the proportion of biologically degradable dissolved organic carbon remains constant and the photochemical degradability increases with terrestrial influence. Thus, degradation potential increases with increasing amounts of terrestrial carbon. Our results provide empirical evidence of a strong causal link between dissolved organic carbon concentrations and aquatic fluxes of carbon dioxide, mediated by the degradation of land-derived organic carbon in aquatic ecosystems. Future shifts in the patterns of terrestrial dissolved organic carbon in inland waters thus have the potential to significantly increase aquatic carbon emissions across northern landscapes.

  10. Effect of physicochemical form on copper availability to aquatic organisms

    SciTech Connect

    Harrison, F.L.

    1983-11-01

    Copper concentration and speciation were determined in influent and effluent waters collected from eight power stations that used copper alloys in their cooling systems. Quantities of copper associated with particles, colloids, and organic and inorganic ligands differed with the site, season, and mode of operation of the station. Under normal operating conditions, the differences between influent and effluent waters were generally small, and most of the copper was in bound (complexed) species. However, copper was high in concentration and present in labile species during start-up of water circulation through some cooling systems and during changeover from an open- to closed-cycle operation. Copper sensitivity of selected ecologically and economically important aquatic organisms was also evaluted. Our primary emphasis was on acute effects and most of the testing was performed under controlled laboratory conditions. However, sublethal effects of copper on a population of bluegills living in a power station cooling lake containing water of low pH were also assessed. The toxic response to copper differed with the species and life stage of the animal and with the chemical form of copper in the water.

  11. Nutrient enrichment affects the mechanical resistance of aquatic plants

    PubMed Central

    Puijalon, Sara

    2012-01-01

    For many plant species, nutrient availability induces important anatomical responses, particularly the production of low-density tissues to the detriment of supporting tissues. Due to the contrasting biomechanical properties of plant tissues, these anatomical responses may induce important modifications in the biomechanical properties of plant organs. The aim of this study was to determine the effects of nutrient enrichment on the anatomical traits of two freshwater plant species and its consequences on plant biomechanical performance. Two plant species were grown under controlled conditions in low versus high nutrient levels. The anatomical and biomechanical traits of the plant stems were measured. Both species produced tissues with lower densities under nutrient-rich conditions, accompanied by modifications in the structure of the aerenchyma for one species. As expected, nutrient enrichment also led to important modifications in the biomechanical properties of the stem for both species. In particular, mechanical resistance (breaking force and strength) and stiffness of stems were significantly reduced under nutrient rich conditions. The production of weaker stem tissues as a result of nutrient enrichment may increase the risk of plants to mechanical failure, thus challenging plant maintenance in mechanically stressful or disturbed habitats. PMID:23028018

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

    SciTech Connect

    Siriwardena, S.N.; Rana, K.J.; Baird, D.J.

    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.

  13. Fractionating nanosilver: importance for determining toxicity to aquatic test organisms.

    PubMed

    Kennedy, Alan J; Hull, Matthew S; Bednar, Anthony J; Goss, Jennifer D; Gunter, Jonas C; Bouldin, Jennifer L; Vikesland, Peter J; Steevens, Jeffery A

    2010-12-15

    This investigation applied novel techniques for characterizing and fractionating nanosilver particles and aggregates and relating these measurements to toxicological endpoints. The acute toxicity of eight nanosilver suspensions of varying primary particle sizes (10-80 nm) and coatings (citrate, polyvinylpyrrolidone, EDTA, proprietary) was assessed using three aquatic test organisms (Daphnia magna, Pimephales promelas, Pseudokirchneriella subcapitata). When 48-h lethal median concentrations (LC50) were expressed as total silver, both D. magna and P. promelas were significantly more sensitive to ionic silver (Ag(+)) as AgNO(3) (mean LC50 = 1.2 and 6.3 μg/L, respectively) relative to a wide range in LC50 values determined for the nanosilver suspensions (2 -126 μg/L). However, when LC50 values for nanosilver suspensions were expressed as fractionated nanosilver (Ag(+) and/or <4 nm particles), determined by ultracentrifugation of particles and confirmed field-flow-fractograms, the LC50 values (0.3-5.6 μg/L) were comparable to the values obtained for ionic Ag(+) as AgNO(3). These results suggest that dissolved Ag(+) plays a critical role in acute toxicity and underscores the importance of characterizing dissolved fractions in nanometal suspensions.

  14. Fundamental study on magnetic separation of aquatic organisms for preservation of marine ecosystem

    NASA Astrophysics Data System (ADS)

    Sakaguchi, F.; Akiyama, Y.; Izumi, Y.; Nishijima, S.

    2009-10-01

    Recently, destruction and disturbance of marine ecosystem have been caused by changes in global environment and transplants of farmed fishes and shellfishes. To solve the problems, water treatment techniques to kill or to remove aquatic organisms are necessary. In this study, application of magnetic separation for removal of the aquatic organisms was examined in order to establish the process with high-speed, compact device and low environmental load. Techniques of magnetic seeding and magnetic separation using superconducting magnet are important for high-speed processing of aquatic organisms. Magnetic seeding is to adhere separating object to the surface of ferromagnetic particles, and magnetic separation is to remove aquatic organisms with magnetic force. First, we confirmed the possibility of magnetic seeding of aquatic organisms, and then interaction between aquatic organisms and ferromagnetic particles was examined. Next, for practical application of magnetic separation system using superconducting magnet for removal of aquatic organisms, particle trajectories were simulated and magnetic separation experiment using superconducting magnet was performed in order to design magnetic separation system to achieve high separation efficiency.

  15. Hydroecology of Intermittent and Ephemeral Streams: Will Landscape Connectivity Sustain Aquatic Organisms in a Changing Climate?

    DTIC Science & Technology

    2015-07-24

    132 5. Ecological strategies predict associations between aquatic and genetic connectivity for dryland amphibians...amphibian and aquatic invertebrate species with contrasting life histories were investigated. How species’ ecological strategies affect the regional...and Boreonectes aequinoctialis (Coleoptera: Dytiscidae)]. These species characterize a range of ecological strategies, driven primarily by

  16. Hydroecology of Intermittent and Ephemeral Streams: Will Landscape Connectivity Sustain Aquatic Organisms in a Changing Climate?

    DTIC Science & Technology

    2015-05-01

    132 5. Ecological strategies predict associations between aquatic and genetic connectivity for dryland amphibians...amphibian and aquatic invertebrate species with contrasting life histories were investigated. How species’ ecological strategies affect the regional...and Boreonectes aequinoctialis (Coleoptera: Dytiscidae)]. These species characterize a range of ecological strategies, driven primarily by

  17. Biogeochemical processes governing exposure and uptake of organic pollutant compounds in aquatic organisms.

    PubMed Central

    Farrington, J W

    1991-01-01

    This paper reviews current knowledge of biogeochemical cycles of pollutant organic chemicals in aquatic ecosystems with a focus on coastal ecosystems. There is a bias toward discussing chemical and geochemical aspects of biogeochemical cycles and an emphasis on hydrophobic organic compounds such as polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and chlorinated organic compounds used as pesticides. The complexity of mixtures of pollutant organic compounds, their various modes of entering ecosystems, and their physical chemical forms are discussed. Important factors that influence bioavailability and disposition (e.g., organism-water partitioning, uptake via food, food web transfer) are reviewed. These factors include solubilities of chemicals; partitioning of chemicals between solid surfaces, colloids, and soluble phases; variables rates of sorption, desorption; and physiological status of organism. It appears that more emphasis on considering food as a source of uptake and bioaccumulation is important in benthic and epibenthic ecosystems when sediment-associated pollutants are a significant source of input to an aquatic ecosystem. Progress with mathematical models for exposure and uptake of contaminant chemicals is discussed briefly. PMID:1904812

  18. Effects of marine toxins on the reproduction and early stages development of aquatic organisms.

    PubMed

    Vasconcelos, Vítor; Azevedo, Joana; Silva, Marisa; Ramos, Vítor

    2010-01-19

    Marine organisms, and specially phytoplankton species, are able to produce a diverse array of toxic compounds that are not yet fully understood in terms of their main targets and biological function. Toxins such as saxitoxins, tetrodotoxin, palytoxin, nodularin, okadaic acid, domoic acid, may be produced in large amounts by dinoflagellates, cyanobacteria, bacteria and diatoms and accumulate in vectors that transfer the toxin along food chains. These may affect top predator organisms, including human populations, leading in some cases to death. Nevertheless, these toxins may also affect the reproduction of aquatic organisms that may be in contact with the toxins, either by decreasing the amount or quality of gametes or by affecting embryonic development. Adults of some species may be insensitive to toxins but early stages are more prone to intoxication because they lack effective enzymatic systems to detoxify the toxins and are more exposed to the toxins due to a higher metabolic growth rate. In this paper we review the current knowledge on the effects of some of the most common marine toxins on the reproduction and development of early stages of some organisms.

  19. Ecotoxicity of selected nano-materials to aquatic organisms.

    PubMed

    Blaise, C; Gagné, F; Férard, J F; Eullaffroy, P

    2008-10-01

    Present knowledge concerning the ecotoxic effects of nano-materials is very limited and merits to be documented more fully. For this purpose, we appraised the toxicity of nine metallic nano-powders (copper zinc iron oxide, nickel zinc iron oxide, yttrium iron oxide, titanium dioxide, strontium ferrite, indium tin oxide, samarium oxide, erbium oxide, and holmium oxide) and of two organic nano- powders (fullerene-C60 and single-walled carbon nanotube or SWCNT). After a simple process where nano-powders (NPs) were prepared in aqueous solution and filtered, they were then bioassayed across several taxonomic groups including decomposers (bacteria), primary producers (micro-algae), as well as primary and secondary consumers (micro-invertebrates and fish). Toxicity data generated on the 11 NPs reflected a wide spectrum of sensitivity that was biological level-, test-, and endpoint-specific. With all acute and chronic tests confounded for these 11 NPs, toxicity responses spanned over three orders of magnitude: >463 mg/L (24 h LC50 of the invertebrate Thamnoplatyurus platyurus for fullerene-C60) / 0.3 mg/L (96 h EC50 of the invertebrate Hydra attenuata for indium tin oxide), that is a ratio of 1543. On the basis of the MARA (Microbial Array for Risk Assessment) assay toxic fingerprint concept, it is intimated that NPs may have different modes of toxic action. When mixed in a 1:1 ratio with a certified reference material (CRM) sediment, two solid phase assays and an elutriate assay, respectively, showed that five NPs (copper zinc iron oxide, samarium oxide, erbium oxide, holmium oxide, and SWCNT) were able to increase both CRM sediment toxicity and its elutriate toxicity. This initial investigation suggests that chemicals emerging from nanotechnology may pose a risk to aquatic life in water column and sediment compartments and that further studies on their adverse effects are to be encouraged.

  20. Teratogenicity and embryotoxicity in aquatic organisms after pesticide exposure and the role of oxidative stress.

    PubMed

    Pašková, Veronika; Hilscherová, Klára; Bláha, Luděk

    2011-01-01

    Many pesticides have been documented to induce embryotoxicity and teratogenicity in non-target aquatic biota such a fish, amphibians and invertebrates. Our review of the existing literature shows that a broad range of pesticides, representing several different chemical classes, induce variable toxic effects in aquatic species. The effects observed include diverse morphological malformations as well as physiological and behavioral effects. When development malformations occur, the myoskeletal system is among the most highly sensitive of targets. Myoskeletal effects that have been documented to result from pesticides were also known to interfere with the development of organ systems including the eyes or the heart and are also known to often cause lethal or sublethal edema in exposed organisms. The Physiological, behavioral, and population endpoints affected by pesticides include low or delayed hatching, growth suppression, as well as embryonal or larval mortality. The risks associated with pesticide exposure increase particularly during the spring. This is the period of time in which major pepticide applications take place, and this period unfortunately also coincides with many sensitive reproductive events such as spawning, egg laying, and early development of many aquatic organisms. Only few experimental studies with pesticides have directly linked developmental toxicity with key oxidative stress endpoints, such as lipid peroxidation, oxidative DNA damage, or modulation of antioxidant mechanisms. On the other hand, it has been documented in many reports that pesticide-related oxidative damage occurs in exposed adult fish, amphibians, and invertebrates. Moreover, the contribution of oxidative stress to the toxicity of pesticides has been emphasized in several recent review papers that have treated this topic. In conclusion, the available experimental data, augmented by several indirect lines of evidence, provide support to the concept that oxidative stress is a

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

    PubMed

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

    2016-08-01

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

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

    USGS Publications Warehouse

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

    2012-01-01

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

  3. Toxicity of TNT Wastewater (Pink Water) to Aquatic Organisms.

    DTIC Science & Technology

    1976-01-01

    to the fathead minnow (Pimephales promelas) and the aquatic invertebrate Daphnia magna . The toxicity tests were conducted on materials that had been...probably the most toxic ingredient of LAP wastewater. The minnow and Daphnia magna were equally sensitive to 2,4-DNT, but the latter was more tolerant of alpha-TNT.

  4. Pelargonic acid - a potential organic aquatic herbicide for duckweed management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Duckweed (Lemna spp.) are small, free floating aquatic plants that flourish on stagnant, or slow moving, water surfaces throughout the continental U.S. Members of the genus are among the smallest flowering plants, providing food for fish and fowl, but their aggressive growth and invasive habit make...

  5. Francisella infections in farmed and wild aquatic organisms

    PubMed Central

    2011-01-01

    Over the last 10 years or so, infections caused by bacteria belonging to a particular branch of the genus Francisella have become increasingly recognised in farmed fish and molluscs worldwide. While the increasing incidence of diagnoses may in part be due to the development and widespread availability of molecular detection techniques, the domestication of new organisms has undoubtedly instigated emergence of clinical disease in some species. Francisellosis in fish develops in a similar fashion independent of host species and is commonly characterised by the presence of multi-organ granuloma and high morbidity, with varying associated mortality levels. A number of fish species are affected including Atlantic cod, Gadus morhua; tilapia, Oreochromis sp.; Atlantic salmon, Salmo salar; hybrid striped bass, Morone chrysops × M. saxatilis and three-lined grunt, Parapristipoma trilinineatum. The disease is highly infectious and often prevalent in affected stocks. Most, if not all strains isolated from teleost fish belong to either F. noatunensis subsp. orientalis in warm water fish species or Francisella noatunensis subsp. noatunensis in coldwater fish species. The disease is quite readily diagnosed following histological examination and identification of the aetiological bacterium by culture on cysteine rich media or PCR. The available evidence may indicate a degree of host specificity for the various Francisella strains, although this area requires further study. No effective vaccine is currently available. Investigation of the virulence mechanisms and host response shows similarity to those known from Francisella tularensis infection in mammals. However, no evidence exists for zoonotic potential amongst the fish pathogenic Francisella. PMID:21385413

  6. Biodegradability of dissolved organic carbon in permafrost soils and aquatic systems: a meta-analysis

    USGS Publications Warehouse

    Jorien E. Vonk,; Tank, Suzanne E.; Paul J. Mann,; Robert G.M. Spencer,; Treat, Claire C.; Striegl, Robert G.; Benjamin W. Abbott,; Wickland, Kimberly P.

    2015-01-01

    As Arctic regions warm and frozen soils thaw, the large organic carbon pool stored in permafrost becomes increasingly vulnerable to decomposition or transport. The transfer of newly mobilized carbon to the atmosphere and its potential influence upon climate change will largely depend on the degradability of carbon delivered to aquatic ecosystems. Dissolved organic carbon (DOC) is a key regulator of aquatic metabolism, yet knowledge of the mechanistic controls on DOC biodegradability is currently poor due to a scarcity of long-term data sets, limited spatial coverage of available data, and methodological diversity. Here, we performed parallel biodegradable DOC (BDOC) experiments at six Arctic sites (16 experiments) using a standardized incubation protocol to examine the effect of methodological differences commonly used in the literature. We also synthesized results from 14 aquatic and soil leachate BDOC studies from across the circum-arctic permafrost region to examine pan-arctic trends in BDOC.An increasing extent of permafrost across the landscape resulted in higher DOC losses in both soil and aquatic systems. We hypothesize that the unique composition of (yedoma) permafrost-derived DOC combined with limited prior microbial processing due to low soil temperature and relatively short flow path lengths and transport times, contributed to a higher overall terrestrial and freshwater DOC loss. Additionally, we found that the fraction of BDOC decreased moving down the fluvial network in continuous permafrost regions, i.e. from streams to large rivers, suggesting that highly biodegradable DOC is lost in headwater streams. We also observed a seasonal (January–December) decrease in BDOC in large streams and rivers, but saw no apparent change in smaller streams or soil leachates. We attribute this seasonal change to a combination of factors including shifts in carbon source, changing DOC residence time related to increasing thaw-depth, increasing water temperatures later

  7. Biodegradability of dissolved organic carbon in permafrost soils and aquatic systems: a meta-analysis

    NASA Astrophysics Data System (ADS)

    Vonk, J. E.; Tank, S. E.; Mann, P. J.; Spencer, R. G. M.; Treat, C. C.; Striegl, R. G.; Abbott, B. W.; Wickland, K. P.

    2015-12-01

    As Arctic regions warm and frozen soils thaw, the large organic carbon pool stored in permafrost becomes increasingly vulnerable to decomposition or transport. The transfer of newly mobilized carbon to the atmosphere and its potential influence upon climate change will largely depend on the degradability of carbon delivered to aquatic ecosystems. Dissolved organic carbon (DOC) is a key regulator of aquatic metabolism, yet knowledge of the mechanistic controls on DOC biodegradability is currently poor due to a scarcity of long-term data sets, limited spatial coverage of available data, and methodological diversity. Here, we performed parallel biodegradable DOC (BDOC) experiments at six Arctic sites (16 experiments) using a standardized incubation protocol to examine the effect of methodological differences commonly used in the literature. We also synthesized results from 14 aquatic and soil leachate BDOC studies from across the circum-arctic permafrost region to examine pan-arctic trends in BDOC. An increasing extent of permafrost across the landscape resulted in higher DOC losses in both soil and aquatic systems. We hypothesize that the unique composition of (yedoma) permafrost-derived DOC combined with limited prior microbial processing due to low soil temperature and relatively short flow path lengths and transport times, contributed to a higher overall terrestrial and freshwater DOC loss. Additionally, we found that the fraction of BDOC decreased moving down the fluvial network in continuous permafrost regions, i.e. from streams to large rivers, suggesting that highly biodegradable DOC is lost in headwater streams. We also observed a seasonal (January-December) decrease in BDOC in large streams and rivers, but saw no apparent change in smaller streams or soil leachates. We attribute this seasonal change to a combination of factors including shifts in carbon source, changing DOC residence time related to increasing thaw-depth, increasing water temperatures later

  8. Environmental monitoring of pesticide exposure and effects on mangrove aquatic organisms of Mozambique.

    PubMed

    Sturve, Joachim; Scarlet, Perpetua; Halling, Maja; Kreuger, Jenny; Macia, Adriano

    2016-10-01

    The use of pesticides in Mozambique is increasing along with the development of agriculture in the country. Mangroves along the coastlines are ecologically important areas and vital nursing grounds for many aquatic species, several of which are of high economic value in Mozambique. Barred mudskipper (Periophthalmus argentilineatus), Jarbua fish (Terapon jarbua), Indian white prawn (Penaeus indicus) and the clam Meretrix meretrix were collected at three mangrove sites in the Maputo Bay area. This was complemented with samplings of the freshwater fish Mozambique tilapia (Oreochromis mossambicus), which was collected from three sampling sites along rivers in the surroundings of Maputo and from three sites along the Olifants and Limpopo River. Acetylcholinesterase (AChE) activity, which is an established biomarker for organophosphates and carbamate pesticides, was measured in brain and liver tissue in fish, and hepatopancreas tissue in prawn and clam. Butyrylcholinesterase (BChE) activity was also analyzed. Freshwater samples for pesticide analyses were collected in order to get an initial understanding of the classes and levels of pesticides present in aquatic systems in Mozambique. In addition to field samplings two 48-h exposure experiments were also conducted where the Indian white prawn and Barred mudskipper were exposed to malathion, and Mozambique tilapia exposed to malathion and diazinon. Field results show a significant decrease in AChE activity in fish from four of the sampling sites suggesting that pesticides present in water could be one stressor potentially affecting aquatic organisms negatively. The 48 h exposure experiment results showed a clear dose-response relationship of AChE activity in mudskipper and tilapia suggesting these species as suitable as sentinel species in environmental studies.

  9. Antibiotics as a chemical stressor affecting an aquatic decomposer-detritivore system.

    PubMed

    Bundschuh, Mirco; Hahn, Torsten; Gessner, Mark O; Schulz, Ralf

    2009-01-01

    Recent evidence indicates that a variety of antibiotic residues may affect the integrity of streams located downstream from wastewater treatment plants. Aquatic communities comprising bacterial and fungal decomposers and invertebrate detritivores (shredders) play an important role in the decomposition of allochthonous leaf litter, which acts as a primary energy source for small running waters. The aim of the present study was to assess whether an antibiotic mixture consisting of sulfamethoxazole, trimethoprim, erythromycin-H2O, roxithromycin, and clarithromycin has an effect on such a decomposer-detritivore system. Leaf discs were exposed to these antibiotics (total concentration of 2 or 200 microg/L) for approximately 20 d before offering these discs and corresponding control discs to an amphipod shredder, Gammarus fossarum, in a food choice experiment. Gammarus preferred the leaf discs conditioned in the presence of the antibiotic mixture at 200 microg/L over the control discs (pair-wise t test; p = 0.006). A similar tendency, while not significant, was observed for leaves conditioned with antibiotics at a concentration of 2 microg/L. The number of bacteria associated with leaves did not differ between treatments at either antibiotic concentration (t test; p = 0.57). In contrast, fungal biomass (measured as ergosterol) was significantly higher in the 200 microg/L treatment (t test; p = 0.038), suggesting that the preference of Gammarus may be related to a shift in fungal communities. Overall these results indicate that mixtures of antibiotics may disrupt important ecosystem processes such as organic matter flow in stream ecosystems, although effects are likely to be weak at antibiotic concentrations typical of streams receiving wastewater treatment plant effluents.

  10. Aquatic Global Passive Sampling (AQUA-GAPS) Revisited: First Steps toward a Network of Networks for Monitoring Organic Contaminants in the Aquatic Environment.

    PubMed

    Lohmann, Rainer; Muir, Derek; Zeng, Eddy Y; Bao, Lian-Jun; Allan, Ian J; Arinaitwe, Kenneth; Booij, Kees; Helm, Paul; Kaserzon, Sarit; Mueller, Jochen F; Shibata, Yasuyuki; Smedes, Foppe; Tsapakis, Manolis; Wong, Charles S; You, Jing

    2017-02-07

    Organic contaminants, in particular persistent organic pollutants (POPs), adversely affect water quality and aquatic food webs across the globe. As of now, there is no globally consistent information available on concentrations of dissolved POPs in water bodies. The advance of passive sampling techniques has made it possible to establish a global monitoring program for these compounds in the waters of the world, which we call the Aquatic Global Passive Sampling (AQUA-GAPS) network. A recent expert meeting discussed the background, motivations, and strategic approaches of AQUA-GAPS, and its implementation as a network of networks for monitoring organic contaminants (e.g., POPs and others contaminants of concern). Initially, AQUA-GAPS will demonstrate its operating principle via two proof-of-concept studies focused on the detection of legacy and emerging POPs in freshwater and coastal marine sites using both polyethylene and silicone passive samplers. AQUA-GAPS is set up as a decentralized network, which is open to other participants from around the world to participate in deployments and to initiate new studies. In particular, participants are sought to initiate deployments and studies investigating the presence of legacy and emerging POPs in Africa, Central, and South America.

  11. Toxicity of Hydrolyzed Chemical Agents to Aquatic Organisms.

    DTIC Science & Technology

    1997-03-01

    may be the most likely candidate for less restrictive disposal methods. 14. SUBJECT TERMS 15. NUMBER OF PAGES Daphnia magna HD GD 20 Aquatic...10 2.4 Daphnia Magna Assay ..................................... 11 2.5 Biomass Growth Study . ................................... 11 3...mortality data was evaluated using the probit analysis that was developed by Tidepool Scientific Software (McKinleyville, CA). 8 2.4 Daphnia Magna

  12. Earth life support for aquatic organisms, system and technical aspects

    NASA Astrophysics Data System (ADS)

    König, B.; Dünne, M.; Slenzka, K.

    The importance of the research on Bioregenerative Life Support has increased dramatically in the last decade not only with regard to possible space flight application but also as a way to obtain a better understanding of our Earth's ecology. A major goal was to reach long-term stability of artificial model systems. Preliminary data are presented on the development of an improved aquatic system, currently dedicated for ground-based research. Closed aquatic ecosystems require reliability of the key parameters of pH, O 2 and CO 2 concentration and stability of sensors for monitoring. Besides the integration of an artificial lung (holofiber system and air pump with valves, allowing controlled oxygen uptake of air), in parallel to the oxygen producing water plants. Our new approach is to implement opto-chemical sensors, for such environmental monitoring. One major advantage of the new sensor technique is their better long-term reliability as compared to the electrochemical sensors. Our experiment with the new sensor technique has demonstrated satisfactory performance in closed aquatic ecosystems.

  13. 40 CFR 158.243 - Experimental use permit data requirements for terrestrial and aquatic nontarget organisms.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Avian dietary toxicity R R R R NR NR TGAI 1, 4 Aquatic Organisms Testing 850.1075 Freshwater fish toxicity R R R NR NR NR TGAI, TEP 1, 2, 5, 6, 11 850.1010 Acute toxicity freshwater invertebrates R R R NR NR NR TGAI, TEP 1, 2, 6, 7, 11 850.1300 Aquatic invertebrate life cycle (freshwater) NR R R NR NR...

  14. The fate of eroded soil organic carbon along a European transect - controls after deposition in terrestrial and aquatic systems

    NASA Astrophysics Data System (ADS)

    Kirkels, Frédérique; Cammeraat, Erik; Kalbitz, Karsten; Van Oost, Kristof; Ellerbrock, Ruth; Folain, Stéphane; Gerke, Horst; Heckrath, Goswin; Kögel-Knabner, Ingrid; Kuhn, Nikolaus; Quinton, John; Salvador-Blanes, Sébastien; Sommer, Michael; Steffens, Markus

    2014-05-01

    The potential fate of eroded soil organic carbon (SOC) after deposition is key to understand carbon cycling in eroding landscapes. Globally, large quantities of sediments and SOC are redistributed by soil erosion on agricultural land, particularly after heavy precipitation events. Deposition of eroded SOC takes place on downslope soils within the catchment and in adjacent inland waters, i.e. substantial amounts of SOC are transferred from terrestrial to aquatic ecosystems. However, the net effect on C exchange between soils, atmosphere and inland waters is unknown. We hypothesize that the turnover of deposited C is significantly affected by soil and organic matter properties, and whether deposition occurs in terrestrial or aquatic environments. We sampled topsoils from 10 agricultural sites along a European transect, spanning a wide range of SOC and soil characteristics (e.g. texture, aggregation, C content, etc.). Turnover of SOC was determined for terrestrial and aquatic depositional conditions in a 10-week incubation study. Moreover, we studied the impact of labile carbon inputs ('priming') on SOC stability using 13C labelled cellulose. We evaluated potentially important controls on the fate of SOC such as amounts and composition of soil organic matter (SOM), distribution of SOC in density fractions and aggregates as well as soil physical and chemical properties. NMR analysis provided an in-depth characterization of SOM quality, showing large similarities in chemical composition among the sites. The role of the microbial biomass was specifically assessed in relation to SOC turnover. The results of our study broadly enhanced our knowledge about controls on SOC decomposition/stabilization after its deposition in terrestrial and aquatic environments. We envisage that our quantitative relationships will contribute to obtain better estimates of the impact of soil erosion on carbon budgets and reduce uncertainties in the linkage between terrestrial and aquatic carbon

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

    PubMed

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

    2017-04-01

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

  16. 40 CFR 158.243 - Experimental use permit data requirements for terrestrial and aquatic nontarget organisms.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... organisms. All terrestrial and aquatic nontarget organism data, as described in paragraph (c) of this... product; TGAI=Technical grade of the active ingredient; commas between the test substances (e.g. TGAI, TEP... note. (c) Table. The following table shows the experimental use data requirements for terrestrial...

  17. A review on factors affecting microcystins production by algae in aquatic environments.

    PubMed

    Dai, Ruihua; Wang, Pinfei; Jia, Peili; Zhang, Yi; Chu, Xincheng; Wang, Yifei

    2016-03-01

    Microcystins, a toxin produced by Microcystis aeruginosa have become a global environmental issue in recent years. As a consequence of eutrophication, microcystins have become widely disseminated in drinking water sources, seriously impairing drinking water quality. This review focuses on the relationship between microcystins synthesis and physical, chemical, and biological environmental factors that are significant in controlling their production. Light intensity and temperature are the more important physical factors, and in many cases, an optimum level for these two factors has been observed. Nitrogen and phosphorus are the key chemical factors causing frequent occurrence of harmful algal blooms and microcystins production. The absorption of nutrients and metabolic activities of algae are affected by different concentrations and forms of nitrogen and phosphorus, leading to variations in microcystins production Metal ions and emerging pollutants are other significant chemical factors, whose comprehensive impact is still being studied. Algae can also interact with biological agents like predators and competitors in aquatic environments, and such interactions are suggested to promote MCs production and release. This review further highlights areas that require further research in order to gain a better understanding of microcystins production. It provides a theoretical basis for the control of microcystins production and releasing into aquatic environments.

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

    PubMed

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

    2011-10-01

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

  19. INTERACTIONS OF SOLAR UV RADIATION AND DISSOLVED ORGANIC MATTER IN AQUATIC ENVIRONMENTS

    EPA Science Inventory

    Changes in the ozone layer over the past two decades have resulted in increases in solar ultraviolet (UV) radiation that reaches the surface of aquatic environments. Recent studies have demonstrated that these UV increases cause changes in photochemical reactions that affect the...

  20. The prognostic significance of the bioaccumulation of heavy metals by aquatic organisms

    SciTech Connect

    Chelomin, V.P.

    1995-12-31

    The conceptual four-stage model, which relates the response of cellular homeostatic and detoxification pathways of aquatic organisms to the increasing environmental heavy metal concentrations, is proposed. Generally, this model is based on the distinction between the bioconcentration and bioaccumulation as two main states of any biological system. According to the theoretical grounds it is assumed the existence of metal concentration threshold in the sea water above which the organism changes from the regulation to the accumulation state. This concentration threshold for different metals, called critical concentration for accumulation (CCA), was quantitatively estimated for various aquatic invertebrates. In the course of heavy metal accumulation there may exist ranges of metal concentrations in the tissues on which the organism implicates various adaptation mechanisms including metabolic regulatory response (the stage of compensatory) and synthesis of specific proteins with a high affinity for metals (the state of expending). Further increase in metal level may result in the spill over of defense systems and in the development of destructive processes (the toxic stage). Concentration ranges of the corresponding stages were quantitatively also estimated using the author`s (an example of marine bivalves) and literature experimental data. This conceptual model provides the scientific basis for assessing both the quality of the aquatic environment and consequences of heavy metal accumulations by aquatic organisms.

  1. Ecotoxicogenomic approaches for understanding molecular mechanisms of environmental chemical toxicity using aquatic invertebrate, Daphnia model organism.

    PubMed

    Kim, Hyo Jeong; Koedrith, Preeyaporn; Seo, Young Rok

    2015-05-29

    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.

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

    PubMed Central

    Kim, Hyo Jeong; Koedrith, Preeyaporn; Seo, Young Rok

    2015-01-01

    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. PMID:26035755

  3. EVALUATION OF MINIMUM DATA REQUIREMENTS FOR ACUTE TOXICITY VALUE EXTRAPOLATION WITH AQUATIC ORGANISMS

    EPA Science Inventory

    Buckler, Denny R., Foster L. Mayer, Mark R. Ellersieck and Amha Asfaw. 2003. Evaluation of Minimum Data Requirements for Acute Toxicity Value Extrapolation with Aquatic Organisms. EPA/600/R-03/104. U.S. Environmental Protection Agency, National Health and Environmental Effects Re...

  4. Assessment of aquatic organisms as bioindicators of historical radionuclide release to the Columbia River

    SciTech Connect

    Dauble, D.D.; Poston, T.M.; Newell, R.L.

    1988-12-01

    This study examined the potential for using several aquatic organisms as biological indicators of historic levels of radionuclides released to the Hanford Reach of the Columbia River. The purpose of the study was to determine the types of environmental samples that could be collected to further our understanding of previous releases of radionuclides at Hanford. Information was initially collected to determine the relative abundance and persistence of radionuclides historically released at Hanford. The potential for long-lived radionuclides to bioaccumulated in aquatic organisms was then assessed. The life history of several common aquatic organisms was examined to evaluate their use as potential bioindicators of radionuclides released to the Columbia River. Considerations for analyzing strontium (ZSr) in biological samples were determined. Based on our review of radionuclides released to the environment and their potential for bioaccumulation in aquatic organisms, strontium appears to be the only radionuclide suitable for further study. White sturgeon (Acipenser transmontanus) and the common mussel (Margaritifera margaritifera) are suitable candidates for developing dose reconstruction scenarios. Considerations for tissue analysis of radionuclide concentration in these species include potential for biological turnover and tissue mass. 48 refs., 1 fig., 4 tabs.

  5. USING GENOMICS AND PROTEOMICS TO DIAGNOSE EXPOSURE OF AQUATIC ORGANISMS TO ENVIRONMENTAL CONTAMINANTS

    EPA Science Inventory

    Advances in molecular biology allow the use of cutting-edge genomic and proteomic tools to assess the effects of environmental contaminants on aquatic organisms. Techniques are available to measure changes in expression of single genes (quantitative real-time PCR) or to measure g...

  6. Pheromones, attractants and other chemical cues of aquatic organisms and amphibians.

    PubMed

    Cummins, Scott F; Bowie, John H

    2012-06-01

    This review covers the subject of pheromones, attractants and other chemical cues of aquatic invertebrates, fishes and amphibians (including salamanders and anurans). Major topics include the sex pheromones of gastropods, salamanders and a giant tree frog, and the conspecific attraction of sperm to ova of some of the organisms and animals described in this review.

  7. Degradation and aquatic toxicity of naphthenic acids in oil sands process-affected waters using simulated wetlands.

    PubMed

    Toor, Navdeep S; Franz, Eric D; Fedorak, Phillip M; MacKinnon, Michael D; Liber, Karsten

    2013-01-01

    Oil sands process-affected waters (OSPWs) produced during the extraction of bitumen at the Athabasca Oil Sands (AOS) located in northeastern Alberta, Canada, are toxic to many aquatic organisms. Much of this toxicity is related to a group of dissolved organic acids known as naphthenic acids (NAs). Naphthenic acids are a natural component of bitumen and are released into process water during the separation of bitumen from the oil sand ore by a caustic hot water extraction process. Using laboratory microcosms as an analogue of a proposed constructed wetland reclamation strategy for OSPW, we evaluated the effectiveness of these microcosms in degrading NAs and reducing the aquatic toxicity of OSPW over a 52-week test period. Experimental manipulations included two sources of OSPW (one from Syncrude Canada Ltd. and one from Suncor Energy Inc.), two different hydraulic retention times (HRTs; 40 and 400 d), and increased nutrient availability (added nitrate and phosphate). Microcosms with a longer HRT (for both OSPWs) showed higher reductions in total NAs concentrations (64-74% NAs reduction, p<0.05) over the test period, while nutrient enrichment appeared to have little effect. A 96 h static acute rainbow trout (Oncorhynchus mykiss) bioassay showed that the initial acute toxicity of Syncrude OSPW (LC50=67% v/v) was reduced (LC50>100% v/v) independent of HRT. However, EC20s from separate Microtox® bioassays were relatively unchanged when comparing the input and microcosm waters at both HRTs over the 52-week study period (p>0.05), indicating that some sub-lethal toxicity persisted under these experimental conditions. The present study demonstrated that given sufficiently long HRTs, simulated wetland microcosms containing OSPW significantly reduced total NAs concentrations and acute toxicity, but left behind a persistent component of the NAs mixture that appeared to be associated with residual chronic toxicity.

  8. Toxicity of Water Accommodated Fractions of Estonian Shale Fuel Oils to Aquatic Organisms.

    PubMed

    Blinova, Irina; Kanarbik, Liina; Sihtmäe, Mariliis; Kahru, Anne

    2016-02-01

    Estonia is the worldwide leading producer of the fuel oils from the oil shale. We evaluated the ecotoxicity of water accommodated fraction (WAF) of two Estonian shale fuel oils ("VKG D" and "VKG sweet") to aquatic species belonging to different trophic levels (marine bacteria, freshwater crustaceans and aquatic plants). Artificial fresh water and natural lake water were used to prepare WAFs. "VKG sweet" (lower density) proved more toxic to aquatic species than "VKG D" (higher density). Our data indicate that though shale oils were very toxic to crustaceans, the short-term exposure of Daphnia magna to sub-lethal concentrations of shale fuel oils WAFs may increase the reproductive potential of survived organisms. The weak correlation between measured chemical parameters (C10-C40 hydrocarbons and sum of 16 PAHs) and WAF's toxicity to studied species indicates that such integrated chemical parameters are not very informative for prediction of shale fuel oils ecotoxicity.

  9. Potential toxicity of pesticides measured in midwestern streams to aquatic organisms

    USGS Publications Warehouse

    Battaglin, W.; Fairchild, J.

    2002-01-01

    Society is becoming increasingly aware of the value of healthy aquatic ecosystems as well as the effects that man's activities have on those ecosystems. In recent years, many urban and industrial sources of contamination have been reduced or eliminated. The agricultural community also has worked towards reducing off-site movement of agricultural chemicals, but their use in farming is still growing. A small fraction, estimated at <1 to 2% of the pesticides applied to crops are lost from fields and enter nearby streams during rainfall events. In many cases aquatic organisms are exposed to mixtures of chemicals, which may lead to greater non-target risk than that predicted based on traditional risk assessments for single chemicals. We evaluated the potential toxicity of environmental mixtures of 5 classes of pesticides using concentrations from water samples collected from ???50 sites on midwestern streams during late spring or early summer runoff events in 1989 and 1998. Toxicity index values are calculated as the concentration of the compound in the sample divided by the EC50 or LC50 of an aquatic organism. These index values are summed within a pesticide class and for all classes to determine additive pesticide class and total pesticide toxicity indices. Toxicity index values greater than 1.0 indicate probable toxicity of a class of pesticides measured in a water sample to aquatic organisms. Results indicate that some samples had probable toxicity to duckweed and green algae, but few are suspected of having significant toxicity to bluegill sunfish or chorus frogs.

  10. METHOD FOR TESTING THE AQUATIC TOXICITY OF SEDIMENT EXTRACTS FOR USE IN IDENTIFYING ORGANIC TOXICANTS IN SEDIMENTS

    EPA Science Inventory

    Biologically-directed fractionation techniques are a fundamental tool for identifying the cause of toxicity in environmental samples, but few are available for studying mixtures of organic chemicals in aquatic sediments. This paper describes a method for extracting organic chemic...

  11. Interactions of carbon nanotubes with aqueous/aquatic media containing organic/inorganic contaminants and selected organisms of aquatic ecosystems--A review.

    PubMed

    Boncel, Sławomir; Kyzioł-Komosińska, Joanna; Krzyżewska, Iwona; Czupioł, Justyna

    2015-10-01

    Due to their unique molecular architecture translating into numerous every-day applications, carbon nanotubes (CNTs) will be ultimately an increasingly significant environmental contaminant. This work reviews qualitative/quantitative analyses of interactions of various types of CNTs and their chemically modified analogues with aqueous/aquatic media containing organic and inorganic contaminants and selected organisms of aquatic ecosystems. A special emphasis was placed on physicochemical interactions between CNTs as adsorbents of heavy metal cations and aromatic compounds (dyes) with its environmental consequences. The studies revealed CNTs as more powerful adsorbents of aromatic compounds (an order of magnitude higher adsorption capacity) than metal cations. Depending on the presence of natural organic matter (NOM) and/or co-contaminants, CNTs may act as Trojan horse while passing through biological membranes (in the absence of NOM coordinating metal ions). Nanotubes, depending on flow conditions and their morphology/surface chemistry, may travel with natural waters or sediment with immobilized PAHs or metals and/or increase cyto- and ecotoxicity of PAHs/metal ions by their release via competitive complexation, or cause synergic ecotoxicity while adsorbing nutrients. Additionally, toxicity of CNTs against exemplary aquatic microorganisms was reviewed. It was found for Daphnia magna that longer exposures to CNTs led to higher ecotoxicity with a prolonged CNTs excretion. SWCNTs were more toxic than MWCNTs, while hydrophilization of CNTs via oxidation or anchoring thereto polar/positively charged polymer chains enhanced stability of nanotubes dispersion in aqueous media. On the other hand, bioavailability of functionalized CNTs was improved leading to more complex both mechanisms of uptake and cytotoxic effects.

  12. Simple Mechanisms for Broadspectrum Color Control in Aquatic Organisms

    DTIC Science & Technology

    2012-02-28

    Diaptomus and the use of a single carotenoid compound to achieve coloration (Figure 1). Specifically, the objectives and approaches were to: 2...have red ovaries and red egg cases. We hypothesized that this is to provide photoprotection and antioxidants (another property of carotenoid pigments...that carotenoid content and color patterning affected copepod sensitivity to ultraviolet light as well as, for the first time, pro-oxidant chemicals

  13. Analysis of current-use pesticides in aquatic and terrestrial organisms collected throughout California, USA

    USGS Publications Warehouse

    Smalling, Kelly L.; Kuivila, Kathyrn M.

    2010-01-01

    A wide variety of pesticides are applied concurrently in agricultural and urban areas and transported off site dissolved in water and bound to sediments. But the exposure of aquatic and terrestrial organisms to current-use pesticides and the resulting effects are not well understood. One approach is to directly analyze tissue concentrations of contaminants. The overall objective of this study was to develop a sensitive method to analyze current-use pesticides with a wide range of Kow's in tissue to better understand the accumulation of these contaminants in different aquatic and terrestrial organisms. This method was then used to analyze current-use pesticides in tissues from a variety of organisms from sites with different land-use practices.

  14. Automatic recognition system of aquatic organisms by classical and fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Lauffer, M.; Genty, F.; Margueron, S.; Collette, J. L.; Pihan, J. C.

    2015-05-01

    Blooming of algae and more generally phytoplankton in water ponds or marine environments can lead to hyper eutrophication and lethal consequences on other organisms. The selective recognition of invading species is investigated by automatic recognition algorithms of optical and fluorescence imaging. On one hand, morphological characteristics of algae of microscopic imaging are treated. The image processing lead to the identification the genus of aquatic organisms and compared to a morphologic data base. On the other hand, fluorescence images allow an automatic recognition based on multispectral data that identify locally the ratio of different photosynthetic pigments and gives a unique finger print of algae. It is shown that the combination of both methods are useful in the recognition of aquatic organisms.

  15. Sludge-grown algae for culturing aquatic organisms: Part II. Sludge-grown algae as feeds for aquatic organisms

    NASA Astrophysics Data System (ADS)

    Wong, M. H.; Hung, K. M.; Chiu, S. T.

    1996-05-01

    This project investigated the feasibility of using sewage sludge to culture microalgae ( Chlorella-HKBU) and their subsequent usage as feeds for rearing different organisms. Part II of the project evaluated the results of applying the sludge-grown algae to feed Oreochromis mossambicus (fish), Macrobrachium hainenese (shrimp), and Moina macrocopa (cladocera). In general, the yields of the cultivated organisms were unsatisfactory when they were fed the sludge-grown algae directly. The body weights of O. mossambicus and M. macrocopa dropped 21% and 37%, respectively, although there was a slight increase (4.4%) in M. hainenese. However, when feeding the algal-fed cladocerans to fish and shrimp, the body weights of the fish and shrimp were increased 7% and 11% accordingly. Protein contents of the cultivated organisms were comparable to the control diet, although they contained a rather high amount of heavy metals. When comparing absolute heavy metal contents in the cultivated organisms, the following order was observed: alga > cladocera > shrimp, fish > sludge extracts. Bioelimination of heavy metals may account for the decreasing heavy metal concentrations in higher trophic organisms.

  16. Methods for estimating doses to organisms from radioactive materials released into the aquatic environment

    SciTech Connect

    Baker, D.A.; Soldat, J.K.

    1992-06-01

    The US Department of Energy recently published an interim dose limit of 1 rad d{sup {minus}1} for controlling the radiation exposure of nature aquatic organisms. A computer program named CRITR, developed previously for calculating radiation doses to aquatic organisms and their predators, has been updated as an activity of the Hanford Site Surface Environmental Surveillance Project to facilitate demonstration of compliance with this limit. This report presents the revised models and the updated computer program, CRITR2, for the assessment of radiological doses to aquatic organisms and their predators; tables of the required input parameters are also provided. Both internal and external doses to fish, crustacea, mollusks, and algae, as well as organisms that subsist on them, such as muskrats, raccoons, and ducks, may be estimated using CRITR2. Concentrations of radionuclides in the water to which the organisms are exposed may be entered directly into the user-input file or may be calculated from a source term and standard dilution models developed for the National Council on Radiation Protection and Measurements.

  17. Comparison of water solubility enhancements of organic solutes by aquatic humic materials and commercial humic acids

    SciTech Connect

    Chiou, C.T.; Kile, D.E.; Brinton, T.I.; Malcolm, R.L.; Leenheer, J.A.; MacCarthy, P.

    1987-12-01

    Water solubility enhancements of 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (p,p'-DDT), 2,4,5,2',5'-pentachlorobiphenyl (2,4,5,2',5'-PCB), and 2,4,4'-trichlorobiphenyl (2,4,4'-PCB) by dissolved organic matter have been studied with the following samples: (1) acidic water samples from the Suwannee River, Georgia, and the Sopchoppy River, Florida; (2) a humic extract of a nearly neutral pH water from the Calcasieu River, Louisiana; (3) commercial humic acids from the Aldrich Chemical Co. and Fluka-Tridom Chemical Corp. The calculated partition coefficients on a dissolved organic carbon basis (K/sub doc/) for organic solutes with water samples and aquatic humic extracts from this and earlier studies indicate that the enhancement effect varies with the molecular composition of the aquatic humic materials, The K/sub doc/ values with water and aquatic humic samples are, however, far less than the observed K/sub doc/ values obtained with the two commercial samples, by factors of about 4-20. In view of this finding, one should be cautious in interpreting the effects of the dissolved organic matter on solubility enhancement of organic solutes on the basis of the use of commercial humic acids. 14 references, 3 figures, 2 tables.

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

    PubMed

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

    2012-04-01

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

  19. Anaerobic biodegradation of (emerging) organic contaminants in the aquatic environment.

    PubMed

    Ghattas, Ann-Kathrin; Fischer, Ferdinand; Wick, Arne; Ternes, Thomas A

    2017-02-03

    Although strictly anaerobic conditions prevail in several environmental compartments, up to now, biodegradation studies with emerging organic contaminants (EOCs), such as pharmaceuticals and personal care products, have mainly focused on aerobic conditions. One of the reasons probably is the assumption that the aerobic degradation is more energetically favorable than degradation under strictly anaerobic conditions. Certain aerobically recalcitrant contaminants, however, are biodegraded under strictly anaerobic conditions and little is known about the organisms and enzymatic processes involved in their degradation. This review provides a comprehensive survey of characteristic anaerobic biotransformation reactions for a variety of well-studied, structurally rather simple contaminants (SMOCs) bearing one or a few different functional groups/structural moieties. Furthermore it summarizes anaerobic degradation studies of more complex contaminants with several functional groups (CMCs), in soil, sediment and wastewater treatment. While strictly anaerobic conditions are able to promote the transformation of several aerobically persistent contaminants, the variety of observed reactions is limited, with reductive dehalogenations and the cleavage of ether bonds being the most prevalent. Thus, it becomes clear that the transferability of degradation mechanisms deduced from culture studies of SMOCs to predict the degradation of CMCs, such as EOCs, in environmental matrices is hampered due the more complex chemical structure bearing different functional groups, different environmental conditions (e.g. matrix, redox, pH), the microbial community (e.g. adaptation, competition) and the low concentrations typical for EOCs.

  20. Boron in Pariette Wetland Sediments, Aquatic Vegetation & Benthic Organisms

    NASA Astrophysics Data System (ADS)

    Vasudeva, P.; Jones, C. P.; Powelson, D.; Jacobson, A. R.

    2015-12-01

    The Pariette Wetlands are comprised of 20 ponds located in Utah's Uintah Basin. Boron concentration in the Pariette Wetlands have been observed to exceed the total maximum daily limit of 750 µg L-1. Considering water flow in and out of the wetlands, boron is accumulating within the wetlands where it is sorbed to sediments and bioconcentrated by wetland plant and macro invertebrates. Since boron is an avian teratogen, an estimate of boron ingestion exposure is warranted. Samples from 3 of the 23 Pariette Wetland ponds with one pond near the inlet, one near the outlet, and one in the middle were collected. Five sampling points were designated along a 100 m transect of each pond. At each sampling point duplicate (or triplicate) samples of water, sediments, benthic organisms and wetland vegetation were collected. The sediments were collected with a KB-corer and divided at depths of 0-2 cm, 2-7 cm, and 7+ cm from the sediment surface. Sample splits were sent to the USU Bug lab for identification of invertebrate species. Whenever this transect was not intercepting vegetation, 2-3 additional sample sites were identified at the pond within stands of representative vegetation where bird nests are located. The plant parts used for boron analyses will include seeds, shoot and roots of vascular plants, as well as algae or duckweeds skimmed from the surface. Samples were processed within 2 days of collection. Water samples filtered through a 0.45 μ membrane filter were analyzed for DOC, pH and ECe. The dried and washed vegetation samples were ground and stored. The benthic organisms and macro invertebrates were netted at the water surface. The dried samples were weighed, ground and stored. Samples were weighed, oven dried and reweighed. For plant and macro-invertebrate samples, a nitric and hydrogen peroxide digestion procedure is used to dissolve environmentally available elements. The Hot Water extraction and DTPA-Sorbitol extraction were compared to estimate wetland plant

  1. Toxicity of a coal liquefaction product to aquatic organisms

    SciTech Connect

    Giddings, J.M.; Parkhurst, B.R.; Gehrs, C.W.; Millemann, R.E.

    1980-01-01

    As coal liquefaction processes approach commercialization in the United States, there is a growing need for information on their potential environmental impacts. Past oil spill experiences will not be adequate for predicting the effects of coal-derived oils, because the latter are chemically quite different from petroleum products. Using acute bioassay tests, a representative coal liquefaction product was compared with a petroluem-derived residual fuel oil and a diesel fuel, materials whose ecological effects have been documented following actual spills over the past 15 years. The acute toxicity of water soluble fractions (WSFs) of the three oils to two freshwater algae and one freshwater crustacean was determined. The WSFs were tested instead of the whole oils because (a) the water soluble components of an oil are responsible for most of its acute toxicity; and (b) while spilled oil can be contained and often recovered, the water with which it comes in contact will affect a larger area and for a longer time.

  2. Factors affecting membership in specialty nursing organizations.

    PubMed

    White, Mary Joe; Olson, Rhonda S

    2004-01-01

    A discouraging trend in many specialty nursing organizations is the stagnant or declining membership. The research committee of the Southeast Texas Chapter of the Association of Rehabilitation Nurses (ARN) collected data and studied this trend to determine what changes would be necessary to increase membership. Using Herzberg's motivational theory as a framework, a review of the literature was initiated. There were few current studies on this issue, but relevant information was found about nursing's emerging workforce, as well as implications of the growth of magnet hospitals, which affect whether nurses join specialty nursing organizations. A multifaceted data-collection approach using convenience samples was designed. First, relevant literature was reviewed. Second, a survey was sent by e-mail to other ARN chapters. Third, a telephone survey on other specialty organizations in the geographic region was completed. Finally, members of the local ARN chapter and four other specialty organizations, as well staff nurses in the geographic area, were given questionnaires to complete. Descriptive statistics and cross tabulations were used to determine why nurses do and do not join specialty organizations (N = 81). The most frequent reasons for joining an organization were to increase knowledge, benefit professionally, network, and earn continuing education units. Reasons for choosing not to participate were family responsibilities, lack of information about these organizations, and lack of time. Ways to reverse the decline in membership are discussed.

  3. Changing agricultural practices: Potential consequences to aquatic organisms

    USGS Publications Warehouse

    Lasier, Peter J.; Urich, Matthew L.; Hassan, Sayed M.; Jacobs, Whitney N.; Bringolf, Robert B.; Owens, Kathleen M.

    2016-01-01

    Agricultural practices pose threats to biotic diversity in freshwater systems with increasing use of glyphosate-based herbicides for weed control and animal waste for soil amendment becoming common in many regions. Over the past two decades, these particular agricultural trends have corresponded with marked declines in populations of fish and mussel species in the Upper Conasauga River watershed in Georgia/Tennessee, USA. To investigate the potential role of agriculture in the population declines, surface waters and sediments throughout the basin were tested for toxicity and analyzed for glyphosate, metals, nutrients, and steroid hormones. Assessments of chronic toxicity with Ceriodaphnia dubia and Hyalella azteca indicated that few water or sediment samples were harmful and metal concentrations were generally below impairment levels. Glyphosate was not observed in surface waters, although its primary degradation product, aminomethyl phosphonic acid (AMPA), was detected in 77% of the samples (mean = 509 μg/L, n = 99) and one or both compounds were measured in most sediment samples. Waterborne AMPA concentrations supported an inference that surfactants associated with glyphosate may be present at levels sufficient to affect early life stages of mussels. Nutrient enrichment of surface waters was widespread with nitrate (mean = 0.7 mg NO3-N/L, n = 179) and phosphorus (mean = 275 μg/L, n = 179) exceeding levels associated with eutrophication. Hormone concentrations in sediments were often above those shown to cause endocrine disruption in fish and appear to reflect the widespread application of poultry litter and manure. Observed species declines may be at least partially due to hormones, although excess nutrients and herbicide surfactants may also be implicated.

  4. Changing agricultural practices: potential consequences to aquatic organisms.

    PubMed

    Lasier, Peter J; Urich, Matthew L; Hassan, Sayed M; Jacobs, Whitney N; Bringolf, Robert B; Owens, Kathleen M

    2016-12-01

    Agricultural practices pose threats to biotic diversity in freshwater systems with increasing use of glyphosate-based herbicides for weed control and animal waste for soil amendment becoming common in many regions. Over the past two decades, these particular agricultural trends have corresponded with marked declines in populations of fish and mussel species in the Upper Conasauga River watershed in Georgia/Tennessee, USA. To investigate the potential role of agriculture in the population declines, surface waters and sediments throughout the basin were tested for toxicity and analyzed for glyphosate, metals, nutrients, and steroid hormones. Assessments of chronic toxicity with Ceriodaphnia dubia and Hyalella azteca indicated that few water or sediment samples were harmful and metal concentrations were generally below impairment levels. Glyphosate was not observed in surface waters, although its primary degradation product, aminomethyl phosphonic acid (AMPA), was detected in 77% of the samples (mean = 509 μg/L, n = 99) and one or both compounds were measured in most sediment samples. Waterborne AMPA concentrations supported an inference that surfactants associated with glyphosate may be present at levels sufficient to affect early life stages of mussels. Nutrient enrichment of surface waters was widespread with nitrate (mean = 0.7 mg NO3-N/L, n = 179) and phosphorus (mean = 275 μg/L, n = 179) exceeding levels associated with eutrophication. Hormone concentrations in sediments were often above those shown to cause endocrine disruption in fish and appear to reflect the widespread application of poultry litter and manure. Observed species declines may be at least partially due to hormones, although excess nutrients and herbicide surfactants may also be implicated.

  5. Priority Substances and Emerging Organic Pollutants in Portuguese Aquatic Environment: A Review.

    PubMed

    Ribeiro, Cláudia; Ribeiro, Ana Rita; Tiritan, Maria Elizabeth

    Aquatic environments are among the most noteworthy ecosystems regarding chemical pollution due to the anthropogenic pressure. In 2000, the European Commission implemented the Water Framework Directive, with the aim of progressively reducing aquatic chemical pollution of the European Union countries. Therefore, the knowledge about the chemical and ecological status is imperative to determine the overall quality of water bodies. Concerning Portugal, some studies have demonstrated the presence of pollutants in the aquatic environment but an overall report is not available yet. The aim of this paper is to provide a comprehensive review about the occurrence of priority substances included in the Water Framework Directive and some classes of emerging organic pollutants that have been found in Portuguese aquatic environment. The most frequently studied compounds comprise industrial compounds, natural and synthetic estrogens, phytoestrogens, phytosterols, pesticides, pharmaceuticals and personal care products. Concentration of these pollutants ranged from few ng L(-1) to higher values such as 30 μg L(-1) for industrial compounds in surface waters and up to 106 μg L(-1) for the pharmaceutical ibuprofen in wastewaters. Compounds already banned in Europe such as atrazine, alkylphenols and alkylphenol polyethoxylates are still found in surface waters, nevertheless their origin is still poorly understood. Beyond the contamination of the Portuguese aquatic environment by priority substances and emerging organic pollutants, this review also highlights the need of more research on other classes of pollutants and emphasizes the importance of extending this research to other locations in Portugal, which have not been investigated yet.

  6. Influence of poultry litter on the toxicity of cadmium to aquatic organisms

    SciTech Connect

    Ghosal, T.K.; Kaviraj, A.

    1996-12-01

    Increased deposition of cadmium in impounded water through atmospheric fallout and runoff water is a growing concern for aquaculture. In India, pisciculture practices are threatened by frequent low to moderate deposition of Cd in ponds. Although several studies have been conducted on Cd toxicity to freshwater organisms, little is known about the interaction of Cd with other chemicals present in the receiving water system. There is evidence that Cd, in the presence of other chemicals, may produce synergistic, additive or antagonistic effect on aquatic organisms. Aquatic ecosystems, heavily enriched by nitrogen and phosphorus, have reduced the stress imposed by Cd. In contrast, chemicals such as KMnO{sub 4} and CoCl{sub 2} used in aquaculture increase Cd toxicity to fish and plankton. Poultry litter is frequently used in pisciculture ponds to enrich nutrients. However, interaction of poultry litter with Cd is not known. 17 refs., 1 fig., 4 tabs.

  7. Ecophotonics: assessment of temperature gradient in aquatic organisms using up-conversion luminescent particles

    NASA Astrophysics Data System (ADS)

    Volkova, E. K.; Yanina, I. Yu; Popov, A. P.; Bykov, A. V.; Gurkov, A. N.; Borvinskaya, E. V.; Timofeyev, M. A.; Meglinski, I. V.

    2017-02-01

    In the frameworks of developing ecophotonics, we consider the possibility of applying luminescence spectroscopy for monitoring conditions of aquatic organisms, aimed at the study and prognosis of the effect of human activity and climate changes on the environment. The method of luminescence spectroscopy in combination with anti-Stokes luminophores (up-conversion particles) used as optical sensors is used for the noninvasive assessment of the temperature gradient in the internal tissues of aquatic organisms. It is shown that the temperature dependence of the intensity ratio observed in the maxima of the luminescence spectrum bands of the particles Y2O3 : Yb, Er, administered in a biological object, is linear. This fact offers a possibility of using the up-conversion particles for assessing the metabolic activity of different tissues, including those in the framework of ecological monitoring.

  8. Non-target effects on aquatic decomposer organisms of imidacloprid as a systemic insecticide to control emerald ash borer in riparian trees.

    PubMed

    Kreutzweiser, David; Good, Kevin; Chartrand, Derek; Scarr, Taylor; Thompson, Dean

    2007-11-01

    Imidacloprid is effective against emerald ash borer when applied as a systemic insecticide. Following stem or soil injections to trees in riparian areas, imidacloprid residues could be indirectly introduced to aquatic systems via leaf fall or leaching. Either route of exposure may affect non-target, aquatic decomposer organisms. Leaves from ash trees treated with imidacloprid at two field rates and an intentionally-high concentration were added to aquatic microcosms. Leaves from trees treated at the two field rates contained imidacloprid concentrations of 0.8-1.3 ppm, and did not significantly affect leaf-shredding insect survival, microbial respiration or microbial decomposition rates. Insect feeding rates were significantly inhibited at foliar concentrations of 1.3 ppm but not at 0.8 ppm. Leaves from intentionally high-dose trees contained concentrations of about 80 ppm, and resulted in 89-91% mortality of leaf-shredding insects, but no adverse effects on microbial respiration and decomposition rates. Imidacloprid applied directly to aquatic microcosms to simulate leaching from soils was at least 10 times more toxic to aquatic insects than the foliar concentrations, with high mortality at 0.13 ppm and significant feeding inhibition at 0.012 ppm.

  9. Proceedings of the fifth international zebra mussel and other aquatic nuisance organisms conference 1995

    SciTech Connect

    Ackerman, J.D.

    1995-06-01

    This report contains articles from the proceedings of the fifth international zebra mussel & other aquatic nuisance organisms conference. Topics include articles on: Zebra mussel life history; Strategies for application of non-oxidizing biocides; examination of the potential of chlorine dioxide for use in zebra mussel veliger control; and ballast water control; overview of the Canadian approach. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  10. Natural and active chemical remediation of toxic metals, organics, and radionuclides in the aquatic environment

    SciTech Connect

    McPherson, G.; Pintauro, P.; O`Connor, S.

    1996-05-02

    This project focuses on the chemical aspects of remediation, with the underlying theme that chemical remediation does occur naturally. Included are studies on the fate of heavy metal and organic contaminants discharged into aquatic environments; accurate assay metal contaminants partitioned into soils, water and tissue; development of novel polymeric membranes and microporous solids for the entrapment of heavy metals; and the development of hybrid chemo-enzymatic oxidative schemes for aromatics decontamination. 49 refs.

  11. Characterization of natural organic matter as major constituents in aquatic systems

    NASA Astrophysics Data System (ADS)

    Frimmel, F. H.

    1998-12-01

    Natural organic matter (NOM) is ubiquitous in global aquatic systems, the mass concentrations ranging from 0.5 to 100 mg/l of organic carbon. The polydispersity of molar masses and the chemical structures comprising NOM give it a multifunctional role in natural environment and in water treatment processes. Important functions include serving as an electron donor in metal complexation, sorption of xenobiotics and adsorption onto mineral phases and onto activated carbon. NOM is partially oxidized during microbial utilization and during water treatment in which it may also become substituted with chlorine leading to a suite of products with toxic relevance. Meaningful methods of NOM characterization would be useful for the development of a predictive capacity for NOM behaviour in different water sources. Among analytical characterization methods, those directly applicable to aqueous samples are most useful and in addition to classical spectroscopic methods, more advanced methods have become available within the last decade. High pressure liquid chromatography using gels have proved useful in combination with UV/vis, fluorescence, light scattering and sensitive dissolved organic carbon detection techniques, yielding information on molecular absorbance, size distribution, molar mass and reactivity. Information on biodegradability of NOM can be deduced from experimental measurement of bacterial growth under defined conditions. The nature and amount of biologically assimilable organic carbon (AOC) in combination with the bacterial cell number and growth rate constants can provide a meaningful characterization of microbial stability in aquatic systems. In addition, determination of directly available and acid or enzymatically hydrolysable amino acids and carbohydrates can add to the understanding of NOM biodegradability over different time scales. The paper gives the results obtained by the application of the different methods for the characterization of aquatic NOM and

  12. The midgut epithelium of aquatic arthropods: a critical target organ in environmental toxicology.

    PubMed Central

    Beaty, Barry J; Mackie, Ryan S; Mattingly, Kimberly S; Carlson, Jonathan O; Rayms-Keller, Alfredo

    2002-01-01

    The midgut epithelium of aquatic arthropods is emerging as an important and toxicologically relevant organ system for monitoring environmental pollution. The peritrophic matrix of aquatic arthropods, which is secreted by the midgut epithelium cells, is perturbed by copper or cadmium. Molecular biological studies have identified and characterized two midgut genes induced by heavy metals in the midgut epithelium. Many other metal-responsive genes (MRGs) await characterization. One of the MRGs codes for an intestinal mucin, which is critical for protecting the midgut from toxins and pathogens. Another codes for a tubulin gene, which is critical for structure and function of the midgut epithelial cells. Perturbation of expression of either gene could condition aquatic arthropod survivorship. Induction of these MRGs is a more sensitive and rapid indicator of heavy-metal pollution than biological assays. Characterization of genes induced by pollutants could provide mechanistic understanding of fundamental cellular responses to pollutants and insight into determinants of aquatic arthropod population genetic structure and survivorship in nature. PMID:12634118

  13. Effects of molecular weight on the diffusion coefficient of aquatic dissolved organic matter and humic substances.

    PubMed

    Balch, J; Guéguen, C

    2015-01-01

    In situ measurements of labile metal species using diffusive gradients in thin films (DGT) passive samplers are based on the diffusion rates of individual species. Although most studies have dealt with chemically isolated humic substances, the diffusion of dissolved organic matter (DOM) across the hydrogel is not well understood. In this study, the diffusion coefficient (D) and molecular weight (MW) of 11 aquatic DOM and 4 humic substances (HS) were determined. Natural, unaltered aquatic DOM was capable of diffusing across the diffusive gel membrane with D values ranging from 2.48×10(-6) to 5.31×10(-6) cm(2) s(-1). Humic substances had diffusion coefficient values ranging from 3.48×10(-6) to 6.05×10(-6) cm(2) s(-1), congruent with previous studies. Molecular weight of aquatic DOM and HS samples (∼500-1750 Da) measured using asymmetrical flow field-flow fractionation (AF4) strongly influenced D, with larger molecular weight DOM having lower D values. No noticeable changes in DOM size properties were observed during the diffusion process, suggesting that DOM remains intact following diffusion across the diffusive gel. The influence of molecular weight on DOM mobility will assist in further understanding and development of the DGT technique and the uptake and mobility of contaminants associated with DOM in aquatic environments.

  14. Trace element trophic transfer in aquatic organisms: A critique of the kinetic model approach

    USGS Publications Warehouse

    Reinfelder, J.R.; Fisher, N.S.; Luoma, S. N.; Nichols, J.W.; Wang, W.-X.

    1998-01-01

    The bioaccumulation of trace elements in aquatic organisms can be described with a kinetic model that includes linear expressions for uptake and elimination from dissolved and dietary sources. Within this model, trace element trophic transfer is described by four parameters: the weight-specific ingestion rate (IR); the assimilation efficiency (AE); the physiological loss rate constant (ke); and the weight-specific growth rate (g). These four parameters define the trace element trophic transfer potential (TTP=IR·AE/[ke+g]) which is equal to the ratio of the steady-state trace element concentration in a consumer due to trophic accumulation to that in its prey. Recent work devoted to the quantification of AE and ke for a variety of trace elements in aquatic invertebrates has provided the data needed for comparative studies of trace element trophic transfer among different species and trophic levels and, in at least one group of aquatic consumers (marine bivalves), sensitivity analyses and field tests of kinetic bioaccumulation models. Analysis of the trophic transfer potentials of trace elements for which data are available in zooplankton, bivalves, and fish, suggests that slight variations in assimilation efficiency or elimination rate constant may determine whether or not some trace elements (Cd, Se, and Zn) are biomagnified. A linear, single-compartment model may not be appropriate for fish which, unlike many aquatic invertebrates, have a large mass of tissue in which the concentrations of most trace elements are subject to feedback regulation.

  15. Application of the Activity Framework for Assessing Aquatic Ecotoxicology Data for Organic Chemicals.

    PubMed

    Thomas, Paul; Dawick, James; Lampi, Mark; Lemaire, Philippe; Presow, Shaun; van Egmond, Roger; Arnot, Jon A; Mackay, Donald; Mayer, Philipp; Galay Burgos, Malyka

    2015-10-20

    Toxicological research in the 1930s gave the first indications of the link between narcotic toxicity and the chemical activity of organic chemicals. More recently, chemical activity has been proposed as a novel exposure parameter that describes the fraction of saturation and that quantifies the potential for partitioning and diffusive uptake. In the present study, more than 2000 acute and chronic algal, aquatic invertebrates and fish toxicity data, as well as water solubility and melting point values, were collected from a series of sources. The data were critically reviewed and grouped by mode of action (MoA). We considered 660 toxicity data to be of acceptable quality. The 328 data which applied to the 72 substances identified as MoA 1 were then evaluated within the activity-toxicity framework: EC50 and LC50 values for all three taxa correlated generally well with (subcooled) liquid solubilities. Acute toxicity was typically exerted within the chemical activity range of 0.01-0.1, whereas chronic toxicity was exerted in the range of 0.001-0.01. These results confirm that chemical activity has the potential to contribute to the determination, interpretation and prediction of toxicity to aquatic organisms. It also has the potential to enhance regulation of organic chemicals by linking results from laboratory tests, monitoring and modeling programs. The framework can provide an additional line of evidence for assessing aquatic toxicity, for improving the design of toxicity tests, reducing animal usage and addressing chemical mixtures.

  16. Evaluation of the aquatic toxicity of two veterinary sulfonamides using five test organisms.

    PubMed

    De Liguoro, Marco; Di Leva, Vincenzo; Gallina, Guglielmo; Faccio, Elisabetta; Pinto, Gabriele; Pollio, Antonino

    2010-10-01

    The aquatic toxicity of sulfaquinoxaline (SQO) and sulfaguanidine (SGD) was evaluated on the following test organisms: Daphnia magna (reproduction test), Pseudokirchneriella subcapitata, Scenedesmus dimorphus, Synecococcus leopoliensis (algal growth inhibition test) and Lemna gibba (duckweed growth inhibition test). Furthermore, the additivity of the two compounds was measured on D. magna (acute immobilisation test) and P. subcapitata (algal growth inhibition test) using the isobologram method. Results show that SQO and SGD are more toxic to green algae and daphnids, respectively, than other veterinary sulfonamides (SAs) and that their mixtures have a less then additive interaction. Taking into account the highest concentrations detected so far in surface waters for SQO (0.112 μg L(-1)) and for SGD (0.145 μg L(-1)) and the lowest NOECs obtained with the five test organisms, divided by an assessment factor of 10, the following PNECs and risk quotients (RQs) were calculated. SQO: PNEC 2 μg L(-1); RQ 0.056. SGD: PNEC 39.5 μg L(-1); RQ 0.004. Consequently, at the concentrations actually detected in the aquatic environment, the two SAs alone should not harm the freshwater organisms. However, it seems advisable, for veterinary mass treatments, the use of other SAs that have a lesser impact on the aquatic environment. Furthermore, considering the high probability of having complex mixtures of different SAs residues in water, each individual contamination should be evaluated by applying to the SAs mixtures the conservative criteria of additivity.

  17. Effects of dissolved organic matter (DOM) on the bioconcentration of organic chemicals in aquatic organisms--a review.

    PubMed

    Haitzer, M; Höss, S; Traunspurger, W; Steinberg, C

    1998-09-01

    Current knowledge on the effects of dissolved organic matter (DOM) on the bioconcentration of organic chemicals in aquatic animals (water fleas, mussels, amphipods and fish) is summarized. A graphical representation of the available data gives an overview of the magnitude of the observed effects. Most of the studies have shown decreases in bioconcentration in the presence of DOM (2 to 98% relative to DOM-free controls). However, at low DOM levels, up to 10 mg/L, also enhancements of bioconcentration due to DOM, ranging from 2 to 303% have been reported. Generally, the change in BCFW (Bioconcentration factor on a wet weight basis) per mg/L DOC was most pronounced at low levels of DOC. The data also show that DOM from different sources with different characteristics and quality can lead to substantial variations in the bioconcentration of organic compounds at comparable levels of DOC. While decreases in bioconcentration have generally been attributed to a lack of bioavailability of DOM-bound chemical, no mechanisms have been proposed to explain increased uptake of xenobiotics caused by DOM.

  18. Environmental constraints upon locomotion and predator-prey interactions in aquatic organisms: an introduction.

    PubMed

    Domenici, P; Claireaux, G; McKenzie, D J

    2007-11-29

    Environmental constraints in aquatic habitats have become topics of concern to both the scientific community and the public at large. In particular, coastal and freshwater habitats are subject to dramatic variability in various environmental factors, as a result of both natural and anthropogenic processes. The protection and sustainable management of all aquatic habitats requires greater understanding of how environmental constraints influence aquatic organisms. Locomotion and predator-prey interactions are intimately linked and fundamental to the survival of mobile aquatic organisms. This paper summarizes the main points from the review and research articles which comprise the theme issue 'Environmental constraints upon locomotion and predator-prey interactions in aquatic organisms'. The articles explore how natural and anthropogenic factors can constrain these two fundamental activities in a diverse range of organisms from phytoplankton to marine mammals. Some major environmental constraints derive from the intrinsic properties of the fluid and are mechanical in nature, such as viscosity and flow regime. Other constraints derive from direct effects of factors, such as temperature, oxygen content of the water or turbidity, upon the mechanisms underlying the performance of locomotion and predator-prey interactions. The effect of these factors on performance at the tissue and organ level is reflected in constraints upon performance of the whole organism. All these constraints can influence behaviour. Ultimately, they can have an impact on ecological performance. One issue that requires particular attention is how factors such as temperature and oxygen can exert different constraints on the physiology and behaviour of different taxa and the ecological implications of this. Given the multiplicity of constraints, the complexity of their interactions, and the variety of biological levels at which they can act, there is a clear need for integration between the fields of

  19. Do organic ligands affect calcite dissolution rates?

    NASA Astrophysics Data System (ADS)

    Oelkers, Eric H.; Golubev, Sergey V.; Pokrovsky, Oleg S.; Bénézeth, Pascale

    2011-04-01

    Steady state Iceland-spar calcite dissolution rates were measured at 25 °C in aqueous solutions containing 0.1 M NaCl and up to 0.05 M dissolved bicarbonate at pH from 7.9 to 9.1 in the presence of 13 distinct dissolved organic ligands in mixed-flow reactors. The organic ligands considered in this study include those most likely to be present in either (1) aquifers at the conditions pertinent to CO 2 sequestration or (2) soil/early diagenetic environments: acetate, phthalate, citrate, EDTA 4-, succinate, D-glucosaminate, L-glutamate, D-gluconate, 2,4-dihydroxybenzoate, 3,4-dihydroxybenzoate, fumarate, malonate, and gallate. Results show that the presence of <0.05 mol/kg of these organic anions changes calcite dissolution rates by less than a factor of 2.5 with the exception of citrate and EDTA 4-. The presence of 0.05 mol/kg citrate and EDTA 4- increases calcite dissolution rates by as much as a factor of 35 and 500, respectively, compared to rates in organic anion-free solutions. Further calcite dissolution experiments were performed in the presence of organic polymers similar to bacterial exudates, cell exopolysaccharides, and analogs of microbial cell envelopes: alginate, lichen extract, humic acid, pectin, and gum xanthan. In no case did the presence of <100 ppm of these organics change calcite dissolution rates by more than a factor of 2.5. Results obtained in this study suggest that the presence of aqueous organic anions negligibly affects calcite forward dissolution rates in most natural environments. Some effect on calcite reactivity may be observed, however, by the presence of organic anions if they change substantially the chemical affinity of the fluid with respect to calcite.

  20. Cyanide-resistant respiration in photosynthetic organs of freshwater aquatic plants.

    PubMed

    Azcón-Bieto, J; Murillo, J; Peñuelas, J

    1987-07-01

    THE RATE AND SENSITIVITY TO INHIBITORS (KCN AND SALICYLHYDROXAMIC ACID[SHAM]) OF RESPIRATORY OXYGEN UPTAKE HAS BEEN INVESTIGATED IN PHOTOSYNTHETIC ORGANS OF SEVERAL FRESHWATER AQUATIC PLANT SPECIES: six angiosperms, two bryophytes, and an alga. The oxygen uptake rates on a dry weight basis of angiosperm leaves were generally higher than those of the corresponding stems. Leaves also had a higher chlorophyll content than stems. Respiration of leaves and stems of aquatic angiosperms was generally cyanide-resistant, the percentage of resistance being higher than 50% with very few exceptions. The cyanide resistance of respiration of whole shoots of two aquatic bryophytes and an alga was lower and ranged between 25 and 50%. These results suggested that the photosynthetic tissues of aquatic plants have a considerable alternative pathway capacity. The angiosperm leaves generally showed the largest alternative path capacity. In all cases, the respiration rate of the aquatic plants studied was inhibited by SHAM alone by about 13 to 31%. These results were used for calculating the actual activities of the cytochrome and alternative pathways. These activities were generally higher in the leaves of angiosperms. The basal oxygen uptake rate of Myriophyllum spicatum leaves was not stimulated by sucrose, malate or glycine in the absence of the uncoupler carbonylcyanide-m-chlorophenylhydrazone (CCCP), but was greatly increased by CCCP, either in the presence or in the absence of substrates. These results suggest that respiration was limited by the adenylate system, and not by substrate availability. The increase in the respiratory rate by CCCP was due to a large increase in the activities of both the cytochrome and alternative pathways. The respiration rate of M. spicatum leaves in the presence of substrates was little inhibited by SHAM alone, but the SHAM-resistant rate (that is, the cytochrome path) was greatly stimulated by the further addition of CCCP. Similarly, the cyanide

  1. Cyanide-resistant respiration in photosynthetic organs of freshwater aquatic plants. [Myriophyllum spicatum

    SciTech Connect

    Azcon-Bieto, J.; Murillo, J.; Penuelas, J.

    1987-07-01

    The rate and sensitivity to inhibitors (KCN and salicylhydroxamic acid(SHAM)) of respiratory oxygen uptake has been investigated in photosynthetic organs of several freshwater aquatic plant species. The oxygen uptake rates on a dry weigh basis of angiosperm leaves were generally higher than those of the corresponding stems. Leaves also had a higher chlorophyll content than stems. Respiration of leaves and stems of aquatic angiosperms was generally cyanide-resistant. The cyanide resistance of respiration of whole shoots of two aquatic bryophytes and an alga was lower. These results suggested that the photosynthetic tissues of aquatic plants have a considerable alternative pathway capacity. The angiosperm leaves generally showed the largest alternative path capacity. In all cases, the respiration rate of the aquatic plants studied was inhibited by SHAM alone by about 13 to 31%. These results were used for calculating the actual activities of the cytochrome and alternative pathways. These activities were generally higher in the leaves of angiosperms. The basal oxygen uptake rate of Myriophyllum spicatum leaves was greatly increased by CCCP, either in the presence or in the absence of substrates. These results suggest that respiration was limited by the adenylate system, and not by substrate availability. The increase in the respiratory rate by CCCP was due to a large increase in the activities of both the cytochrome and alternative pathways. The respiration rate of M. spicatum leaves in the presence of substrates was little inhibited by SHAM alone, but the SHAM-resistant rate (that is, the cytochrome path) was greatly stimulated by the further addition of CCCP. Similarly, the cyanide-resistant rate of O/sub 2/ uptake was also increased by the uncoupler.

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

    EPA Science Inventory

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

  3. Impact of pretilachlor herbicide and pyridaphenthion insecticide on aquatic organisms in model streams.

    PubMed

    Takahashi, Yoshiyuki; Houjyo, Toshihiko; Kohjimoto, Toshiki; Takagi, Yutaka; Mori, Katsuhiko; Muraoka, Tetsuro; Annoh, Hirochika; Ogiyama, Kazuhiro; Funaki, Yuki; Tanaka, Kaoru; Wada, Yutaka; Fujita, Toshikazu

    2007-06-01

    To detect the impact of pesticides on aquatic organisms, model streams (3m wide, 20 m long) were established in paddy field in Japan. More than 100 species of aquatic organisms were generated in the model streams. Field tests with pretilachlor herbicide and pyridaphenthion insecticide were carried out in the streams for 3 yr (2001-2003). Exposure of pretilachlor (max. 0.382 mg/L) showed little density changes in algae with a Bray-Curtis percent similarity in the range 81.6-93.3% for algae. Exposure to high concentrations (>0.1mg/L) of pyridaphenthion produced visible density reductions in Cladocera zooplankton species. Reduction of individual aquatic insects in the model streams by pyridaphenthion caused an increase of chlorophyll a greater than that of the control streams. The pesticides used showed no substantial differences in the ecosystems of model streams exposed to maximum environmental concentrations (e.g., 0.01 mg/L) detected in real rivers.

  4. Mosquitocidal essential oils: are they safe against non-target aquatic organisms?

    PubMed

    Conti, Barbara; Flamini, Guido; Cioni, Pier Luigi; Ceccarini, Lucia; Macchia, Mario; Benelli, Giovanni

    2014-01-01

    In latest years, the importance of the Melaleuca alternifolia essential oil (EO) has been greatly empathised due to its anti-microbial and anti-inflammatory effects, as well as to its toxic properties towards many arthropods of great medical and veterinary importance. In this research, the EO extracted from aerial parts of M. alternifolia was evaluated for its toxicity against larvae of the most invasive mosquito worldwide, Aedes albopictus (Diptera: Culicidae), and towards adults of the water flea, Daphnia magna (Cladocera: Crustacea), a non-target aquatic organism that share the same ecological niche of A. albopictus. The chemical composition of M. alternifolia EO was investigated by GC-MS analysis. Tea tree EO was mainly composed by oxygenated monoterpenes, with 1,8-cineole as the major constituent. M. alternifolia EO exerted toxic activity against A. albopictus larvae, with a LC50 = 267.130 ppm. However, this EO had a remarkable acute toxicity also towards adults of the non-target arthropod D. magna, with a LC50 = 80.636 ppm. This research provide useful information for the development of newer and safer mosquito control tools, highlighting that the non-target effects against aquatic organisms that share the same ecological niche of A. albopictus larvae are crucial in the development of ecofriendly mosquito control strategies. Further research is needed to investigate the chronic and/or reproductive toxicity of M. alternifolia EO both towards target and non-target aquatic arthropods.

  5. Alternative tissue analysis method developed for organochlorine contaminants in aquatic organisms

    SciTech Connect

    Shan, T.H.; Hopple, J.A.; Foster, G.D. )

    1994-09-01

    The exposure of aquatic life to organochlorine contaminants has been investigated during the past two decades because of human and ecosystem health concerns related to the bioaccumulation of hazardous, lipophilic substances. The toxic effects of polychlorodibenzo-p-dioxines and polychlorinated biphenyls (PCBs) are well known, and recent evidence also suggests that low level exposure to lipophilic organochlorines may interfere with normal development during sensitive early life history stages. As the use of lipophilic organochlorines, such as DDT, in third world countries continues and with the purported global cycling and food chain accumulation of persistent organochlorines, the occurrence of these compounds in aquatic organisms is a critical global environmental issue. An understanding of the fate of organochlorines in the environmental clearly remains an extremely important subject related to water quality. The U.S. Geological Survey (USGS) has recently gained congressional approval in the United States to track nation wide trends in water quality through the establishment of the National Water Quality Assessment Program (NAWQA). Among the goals defined by NAWQA, aquatic organisms, including fish, shellfish, and plants, collected from major drainage basins will be analyzed for, along with other contaminants, polychlorinated biphenyls (PCBs), organochlorine insecticides, and chlorobenzenes. The purpose of this report is to present quality assurance data obtained from the development of a PCB, chlorobenzene, and organochlorine insecticide tissue analysis method in support of NAWQA and other large-scale water quality programs conducted through our laboratory. 12 refs., 1 fig., 2 tabs.

  6. Removal of high organic loads from winery wastewater by aquatic plants.

    PubMed

    Zimmels, Y; Kirzhner, F; Schreiber, J

    2008-09-01

    Laboratory- and field-scale purification tests of raw and diluted winery wastewater (WWW) were carried out using aquatic plants at high organic loads. The laboratory tests were performed using artificial light at 1800 to 1900 lux. The objective of the current study was to define the potential of floating and emergent aquatic macrophytes and the microorganisms attached to their roots, to reduce high organic loads that characterize WWW, thereby providing, for these effluents, an effective treatment and management system. These microorganisms are believed to have a major role in the treatment process. In this context, the potential of floating and emergent macrophytes to improve the water quality of raw compared with diluted WWW was evaluated. In raw WWW (chemical oxygen demand [COD] 5.6 g/L),growth inhibition of both water hyacinth (Eichhornia crassipes) and water pennywort (Hydrocotyle umbellata) was observed. A 1:1 dilution of WWW with fresh (tap) water facilitated growth of these plants. At this dilution level, growth of pennywort was limited, while that of water hyacinth was robust. In terms of reductions in biochemical oxygen demand, COD, and total suspended solids, both water hyacinth and pennywort performed better in diluted compared with raw WWW. At 1:1 and 1:3 dilution, 95.9 to 97% of the COD was removed after 23 days, in the presence of Hydrocotyle and Eichhornia plants and aeration. The capacity of new emergent plants to remove high organic loads from WWW, at enhanced kinetics, was demonstrated. This unique property was tested and compared with the role of the gravel media that support growth of the high-capacity emergent plants. In the presence of reed and salt marsh plants, 83 to 99% of the COD was removed within a period of 24 to 29 days, at 1.5:1 dilution. The new emergent plants proved to be effective, even at record high levels of COD. At an initial level of 16,460 mg/L, the COD was brought down to 2870 mg/L after 24 days (82.6% removal), while 12

  7. Guidelines for biomonitoring persistent organic pollutants (POPs), using lichens and aquatic mosses--a review.

    PubMed

    Augusto, Sofia; Máguas, Cristina; Branquinho, Cristina

    2013-09-01

    During the last decades, awareness regarding persistent organic pollutants (POPs), such dioxins and furans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs), has become a cutting-edge topic, due to their toxicity, bioaccumulation and persistency in the environment. Monitoring of PCDD/Fs and PAHs in air and water has proven to be insufficient to capture deposition and effects of these compounds in the biota. To overcome this limitation, environmental biomonitoring using lichens and aquatic mosses, have aroused as promising tools. The main aim of this work is to provide a review of: i) factors that influence the interception and accumulation of POPs by lichens; ii) how lichens and aquatic bryophytes can be used to track different pollution sources and; iii) how can these biomonitors contribute to environmental health studies. This review will allow designing a set of guidelines to be followed when using biomonitors to assess environmental POP pollution.

  8. The mysteriously variable half-life of dissolved organic matter in aquatic ecosystems: artefact or insight?

    NASA Astrophysics Data System (ADS)

    Evans, Chris; Fovet, Ophelie; Jones, Tim; Jones, Davey; Moldan, Filip; Futter, Martyn

    2016-04-01

    Dissolved organic matter (DOM) fluxes from land to water represent an important loss term in the terrestrial carbon balance, a major pathway in the global carbon cycle, a significant influence on aquatic light, nutrient and energy regimes, and an important concern for drinking water production. Although freshwaters are now recognised as zones of active carbon cycling, rather than passive conduits for carbon transport, evidence regarding the magnitude of, and controls on, DOM cycling in aquatic systems is incomplete and in some cases seemingly contradictory, with DOM 'half-lives' ranging from a few days to many years. Bringing together experimental, isotopic, catchment mass balance and modelling data, we suggest that apparently conflicting results can be reconciled through understanding of differences in: i) the terrestrial sources of DOM within heterogeneous landscapes, and consequent differences in its reactivity and stoichiometry; ii) experimental methodologies (i.e. which reactions are actually being measured), and iii) the extent of prior transformation of DOM upstream of the point of study. We argue that rapid photo-degradation, particularly of peat-derived DOM, is a key process in headwaters, whilst apparently slow DOM turnover in downstream, agriculturally-influenced lakes and rivers can partly be explained by the offsetting effect of in situ DOM production. This production appears to be strongly constrained by nutrient supply, thus linking DOM turnover and composition to the supply of inorganic nutrient inputs from diffuse agricultural pollution, and also providing a possible mechanistic link between aquatic DOM production and terrestrial DOM breakdown via the mineralisation and re-assimilation of organic nutrients. A more complete conceptual understanding of these interlinked processes will provide an improved understanding of the sources and fate of aquatic DOM, its role in the global carbon cycle, and the impact of anthropogenic activities, for example

  9. The aquatic vascular plant Ruppia maritima as an indicator organisms for contaminated sediments

    SciTech Connect

    Tagliabue, M.D.; Thursby, G.B.; Walker, H.A.; Johnston, R.K.

    1994-12-31

    An ongoing estuarine ecological risk assessment case study for the Portsmouth Naval Shipyard in the Great Bay (Kittery, ME, Portsmouth, NH) has been the catalyst for continued methods development with a rooted aquatic plant for a sediment toxicity test. A test using the aquatic vascular plant Ruppia maritima would be similar in it`s utility to the Algal (Champia parvula) Reproduction Test, an accepted, short term test (US EPA Short term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms). Laboratory studies were conducted to evaluate effects of lead, the primary site contaminant on R. maritima in the Great Bay. Morphology and life cycle of R. maritima are similar to that of the aquatic vascular plant Zostra marina which comprises up to 46% of the Great Bay habitat (Short 1992). R. maritima`s reduced size makes it a practical laboratory organism and Ruppia`s effects may offer useful insights into potential effects on Zostra or other aquatic vascular plants. Presently rooted vascular plants are not found in the site of concern (Clark Cove). This can be contributed to either of two factors; the physical parameters of the site, i.e., a depositional zone or the chemical parameters, i.e., metals contamination, specifically lead. Exposure of bedded and nonbedded plants occurred over a four day and ten day period using lead sulfate. Concentrations for bedded exposures were as follows, 0.3, 0.5, 0.8, 1.0 simultaneously extracted metal/acid volatile sulfide (SEM/AVS) molar ratios, and 0.1, 1.0, 10.0 and 100.0mg/l Pb for water only exposures. Some reduction in cumulative leaf growth was observed in the site samples as well as the spiked samples as compared to site controls. Results of this study and associated research which focuses on the further development of the Ruppia test methods will be presented.

  10. Toxicity of five antibiotics and their mixtures towards photosynthetic aquatic organisms: implications for environmental risk assessment.

    PubMed

    González-Pleiter, Miguel; Gonzalo, Soledad; Rodea-Palomares, Ismael; Leganés, Francisco; Rosal, Roberto; Boltes, Karina; Marco, Eduardo; Fernández-Piñas, Francisca

    2013-04-15

    The individual and combined toxicities of amoxicillin, erythromycin, levofloxacin, norfloxacin and tetracycline have been examined in two organisms representative of the aquatic environment, the cyanobacterium Anabaena CPB4337 as a target organism and the green alga Pseudokirchneriella subcapitata as a non-target organism. The cyanobacterium was more sensitive than the green alga to the toxic effect of antibiotics. Erythromycin was highly toxic for both organisms; tetracycline was more toxic to the green algae whereas the quinolones levofloxacin and norfloxacin were more toxic to the cyanobacterium than to the green alga. Amoxicillin also displayed toxicity to the cyanobacterium but showed no toxicity to the green alga. The toxicological interactions of antibiotics in the whole range of effect levels either in binary or multicomponent mixtures were analyzed using the Combination Index (CI) method. In most cases, synergism clearly predominated both for the green alga and the cyanobacterium. The CI method was compared with the classical models of additivity Concentration Addition (CA) and Independent Action (IA) finding that CI could accurately predict deviations from additivity. Risk assessment was performed by calculating the ratio between Measured Environmental Concentration (MEC) and the Predicted No Effect Concentration (PNEC). A MEC/PNEC ratio higher than 1 was found for the binary erythromycin and tetracycline mixture in wastewater effluents, a combination which showed a strong synergism at low effect levels in both organisms. From the tested antibiotic mixtures, it can be concluded that certain specific combinations may pose a potential ecological risk for aquatic ecosystems with the present environmentally measured concentrations.

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

    PubMed

    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

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

    PubMed

    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.

  13. The aquatic vascular plant Ruppia maritima as an indicator organism for contaminated sediments

    SciTech Connect

    Tagliabue, M.D.; Thursby, G.B.; Walker, H.A.; Johnston, R.K.

    1995-12-31

    An ongoing estuarine ecological risk assessment case study for the Portsmouth Naval Shipyard in the Great Bay Estuary (New Hampshire, Maine) was the catalyst to continue development a rooted aquatic plant sediment toxicity test. Laboratory studies were conducted to evaluate effects of lead, the primary site contaminant on R. maritima in the Great Bay. Although the aquatic vascular plant Zostra marina comprises up to 46% of the Great Bay subtidal habitat, R. maritima`s much smaller size makes it a more practical laboratory organism. Effects on Ruppia may offer useful insights into potential effects on Zostra or other aquatic vascular plants. Presently rooted vascular plants are not found in Clark Cove located adjacent to a landfill disposal site on the shipyard. The absence of rooted vegetation can be contributed to, physical parameters of the site (turbidity, grain size, texture) or chemical parameters (heavy metal/Pb contamination, redox potential). Exposure of bedded and nonbedded plants occurred over a four day and ten day period using lead sulfate. Concentrations for bedded exposures were as follows, 0.3, 0.5, 0.8, 1.0 simultaneously extracted metal/acid volatile sulfide (SEM/AVS) molar ratios, and 0.1, 1.0, 10.0 and 100.0mg/l Pb for water only exposures. Reduction in cumulative leaf growth was observed for the Clark Cove sediments as well as the spiked sediments as compared to reference sediments.

  14. Dissolved Organic Carbon Dynamics Along Terrestrial-aquatic Flowpaths in a Catchment Dominated by Sandy Soils

    NASA Astrophysics Data System (ADS)

    Wickland, K.; Walker, J. F.; Hood, K.; Butler, K. D.

    2015-12-01

    Aquatic systems receive significant amounts of terrestrially-derived dissolved organic carbon (DOC) from their watersheds. The amount and nature received depends on terrestrial carbon source strength, processing and losses of carbon during transport, and hydrologic connectivity between terrestrial and aquatic systems. While much research has been done on terrestrial DOC dynamics along terrestrial-aquatic flowpaths, there is still considerable uncertainty in many areas including the importance of different carbon sources, microbial metabolism and sorption of DOC, and processing of carbon in groundwater. Here we investigate DOC dynamics in soils, groundwater, and stream waters at the USGS Water, Energy, and Biogeochemical (WEBB) Program research site in northern Wisconsin. This site is well-suited for studying DOC dynamics as soils are sandy and homogenous with small DOC sorption potential, and previous work has characterized the hydrology of the region in detail. We collected water samples over two years from soil pit lysimeters along a series of hillslope transects, from shallow and deep groundwater wells, and from a first-order stream receiving these waters. We measured DOC concentration, DOC optical properties, and biodegradability of DOC. Combined with historical DOC and companion water chemistry data we characterize DOC generation and loss along the following flowpaths: 1) infiltration through the unsaturated zone to the groundwater table, 2) shallow groundwater flow, and 3) long groundwater flowpaths of different origin (lake-derived vs. terrestrial-derived water).

  15. Toxicity of Jet A (aviation fuel) selected aquatic organisms. Technical report, August 1987-February 1988

    SciTech Connect

    Haley, M.V.; Landis, W.G.

    1989-03-01

    JP8 (jet propulsion) is an aviation fuel being considered for replacement of diesel fuel used in the generation of smoke on the battlefield. JP8 is projected to be more economical and also be used as a fuel for the ground machinery used in the transport and dissemination of JP8. Also, fog oil has naphthene constituents above the Occupational Safety and Health Administration (OSHA) standards. JP8 trailing and testing could lead to contaminating surrounding aquatic ecosystems through runoff or wind transport. Therefore, the toxicity of JP8 to aquatic organisms must be known. Jet A (aviation fuel) was substituted for JP8 due to availability and similar distillation procedure. The aquatic toxicity of the soluble fraction of Jet A (aviation fuel) was examined. Acute 48-hr bioassays were performed using the water flea, Daphnia magna, and 96-hr growth inhibition bioassays were performed using a green unicellular alga, Selenastrum capricornutum. All tests were conducted according to guidelines set by the U.S. Environmental Protection Agency (EPA) and the American Society for Testing and Materials (ASTM). The 48-hr EC50 for D. magna was 3.1 mg/L. The 96-hr IC50 for S. capricornutum was 4.2 mg/L.

  16. Toxicological impacts of antibiotics on aquatic micro-organisms: A mini-review.

    PubMed

    Välitalo, Pia; Kruglova, Antonina; Mikola, Anna; Vahala, Riku

    2017-02-22

    Antibiotics are found globally in the environment at trace levels due to their extensive consumption, which raises concerns about the effects they can have on non-target organisms, especially environmental micro-organisms. So far the majority of studies have focused on different aspects of antibiotic resistance or on analyzing the occurrence, fate, and removal of antibiotics from hospital and municipal wastewaters. Little attention has been paid to ecotoxicological effects of antibiotics on aquatic micro-organisms although they play a critical role in most ecosystems and they are potentially sensitive to these substances. Here we review the current state of research on the toxicological impacts of antibiotics to aquatic micro-organisms, including proteobacteria, cyanobacteria, algae and bacteria commonly present in biological wastewater treatment processes. We focus on antibiotics that are poorly removed during wastewater treatment and thus end up in surface waters. We critically discuss and compare the available analytical methods and test organisms based on effect concentrations and identify the knowledge gaps and future challenges. We conclude that, in general, cyanobacteria and ammonium oxidizing bacteria are the most sensitive micro-organisms to antibiotics. It is important to include chronic tests in ecotoxicological assessment, because acute tests are not always appropriate in case of low sensitivity (for example for proteobacteria). However, the issue of rapid development of antibiotic resistance should be regarded in chronic testing. Furthermore, the application of other species of bacteria and endpoints should be considered in the future, not forgetting the mixture effect and bacterial community studies. Due to differences in the sensitivity of different test organisms to individual antibiotic substances, the application of several bioassays with varying test organisms would provide more comprehensive data for the risk assessment of antibiotics

  17. Current Advances on Virus Discovery and Diagnostic Role of Viral Metagenomics in Aquatic Organisms

    PubMed Central

    Munang'andu, Hetron M.; Mugimba, Kizito K.; Byarugaba, Denis K.; Mutoloki, Stephen; Evensen, Øystein

    2017-01-01

    The global expansion of the aquaculture industry has brought with it a corresponding increase of novel viruses infecting different aquatic organisms. These emerging viral pathogens have proved to be a challenge to the use of traditional cell-cultures and immunoassays for identification of new viruses especially in situations where the novel viruses are unculturable and no antibodies exist for their identification. Viral metagenomics has the potential to identify novel viruses without prior knowledge of their genomic sequence data and may provide a solution for the study of unculturable viruses. This review provides a synopsis on the contribution of viral metagenomics to the discovery of viruses infecting different aquatic organisms as well as its potential role in viral diagnostics. High throughput Next Generation sequencing (NGS) and library construction used in metagenomic projects have simplified the task of generating complete viral genomes unlike the challenge faced in traditional methods that use multiple primers targeted at different segments and VPs to generate the entire genome of a novel virus. In terms of diagnostics, studies carried out this far show that viral metagenomics has the potential to serve as a multifaceted tool able to study and identify etiological agents of single infections, co-infections, tissue tropism, profiling viral infections of different aquatic organisms, epidemiological monitoring of disease prevalence, evolutionary phylogenetic analyses, and the study of genomic diversity in quasispecies viruses. With sequencing technologies and bioinformatics analytical tools becoming cheaper and easier, we anticipate that metagenomics will soon become a routine tool for the discovery, study, and identification of novel pathogens including viruses to enable timely disease control for emerging diseases in aquaculture. PMID:28382024

  18. Current Advances on Virus Discovery and Diagnostic Role of Viral Metagenomics in Aquatic Organisms.

    PubMed

    Munang'andu, Hetron M; Mugimba, Kizito K; Byarugaba, Denis K; Mutoloki, Stephen; Evensen, Øystein

    2017-01-01

    The global expansion of the aquaculture industry has brought with it a corresponding increase of novel viruses infecting different aquatic organisms. These emerging viral pathogens have proved to be a challenge to the use of traditional cell-cultures and immunoassays for identification of new viruses especially in situations where the novel viruses are unculturable and no antibodies exist for their identification. Viral metagenomics has the potential to identify novel viruses without prior knowledge of their genomic sequence data and may provide a solution for the study of unculturable viruses. This review provides a synopsis on the contribution of viral metagenomics to the discovery of viruses infecting different aquatic organisms as well as its potential role in viral diagnostics. High throughput Next Generation sequencing (NGS) and library construction used in metagenomic projects have simplified the task of generating complete viral genomes unlike the challenge faced in traditional methods that use multiple primers targeted at different segments and VPs to generate the entire genome of a novel virus. In terms of diagnostics, studies carried out this far show that viral metagenomics has the potential to serve as a multifaceted tool able to study and identify etiological agents of single infections, co-infections, tissue tropism, profiling viral infections of different aquatic organisms, epidemiological monitoring of disease prevalence, evolutionary phylogenetic analyses, and the study of genomic diversity in quasispecies viruses. With sequencing technologies and bioinformatics analytical tools becoming cheaper and easier, we anticipate that metagenomics will soon become a routine tool for the discovery, study, and identification of novel pathogens including viruses to enable timely disease control for emerging diseases in aquaculture.

  19. The Toxicity of Nitroguanidine and Photolyzed Nitroguandine to Freshwater Aquatic Organisms

    DTIC Science & Technology

    1985-03-01

    Paratanytarsus dissimlils), and aquatic worms ( Lumbriculus variegatus ). The. IN) tWS UCLASSIFIED SEURIY4T CLAISIPICAtIOW OF TNIS PAGE (1160 Date U40*4. I. II...2868 0 ( Lumbriculus variegatue ) 1785 0 (1.49 0 a. The high, low, and control NGu concentrations are listed for each test. The top concentration tested...Bailey, H.C. and D.H.W. Liu. 1980. Lumbriculus variegatus , a benthic oligochaete, as a bioassay organism. In: A.L. Buikema and J. Cairns, Jr., eds

  20. Modeling organic chemical fate in aquatic systems: Significance of bioaccumulation and relevant time-space scales

    SciTech Connect

    Thomann, R.V.

    1995-06-01

    The importance of aquatic food chain bioaccumulation of organic chemicals in contributing to human dose is derived. It is shown that for chemicals with log octanol water partition coefficients greater than about 3, the role of food chain transfer to fish consumed by humans becomes the more dominant route over drinking water. Modeling of aquatic food chain bioaccumulation then becomes necessary to accurately estimate dose of such chemicals to humans. The relevant time and space scales for groundwater and surface water also indicate a division of organic chemicals at a log octanol water partition coefficient of about 3. For chemicals greater than that level, groundwater transport is minimal, while for chemicals with log octanol water coefficients of less than about 3, detention times are long relative to surface water and biodegradation processes become more significant. An illustration is given of modeling the groundwater transport of two organic chemicals (BCEE and benzene) and a metal (chromium) at a Superfund site. The model indicates that after 10 years only a relatively small fraction of the chemicals had traveled in the groundwater about 300 m to the point of release from the site to surface water. On the other hand, steady state in the adjacent stream and lake is reached rapidly over a distance of 2000 m, illustrating the difference in spatial and temporal scales for the groundwater and surface water. 15 refs., 8 figs., 1 tab.

  1. Off-site impacts of agricultural composting: role of terrestrially derived organic matter in structuring aquatic microbial communities and their metabolic potential.

    PubMed

    Pommier, Thomas; Merroune, Asmaa; Bettarel, Yvan; Got, Patrice; Janeau, Jean-Louis; Jouquet, Pascal; Thu, Thuy D; Toan, Tran D; Rochelle-Newall, Emma

    2014-12-01

    While considered as sustainable and low-cost agricultural amendments, the impacts of organic fertilizers on downstream aquatic microbial communities remain poorly documented. We investigated the quantity and quality of the dissolved organic matter leaching from agricultural soil amended with compost, vermicompost or biochar and assessed their effects on lake microbial communities, in terms of viral and bacterial abundances, community structure and metabolic potential. The addition of compost and vermicompost significantly increased the amount of dissolved organic carbon in the leachate compared with soil alone. Leachates from these additions, either with or without biochar, were highly bioavailable to aquatic microbial communities, although reducing the metabolic potential of the community and harbouring more specific communities. Although not affecting bacterial richness or taxonomic distributions, the specific addition of biochar affected the original lake bacterial communities, resulting in a strongly different community. This could be partly explained by viral burst and converging bacterial abundances throughout the samples. These results underline the necessity to include off-site impacts of agricultural amendments when considering their cascading effect on downstream aquatic ecosystems.

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

    ERIC Educational Resources Information Center

    Blaine, Thomas W.; Lichtkoppler, Frank R.

    2016-01-01

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

  3. Aquatic Plant Control Research Program. Effects of Organic Amendments to Sediment on Freshwater Macrophyte Growth.

    DTIC Science & Technology

    1983-10-01

    Wiley and Sons, New York. Anderson, L. W. 1978. Abscisic acid induces formation of floating leaves in the heterophyllous aquatic angiosperm Potamogeton...availability for the growth of angiosperm aquatic plants. Limnology and Oceanography, 11, 529-537. Godfrey, R. K., and Wooten, J. W. 1979. Aquatic and...pp 258-264. . 1978. Decomposition of aquatic angiosperms II. Particu- late components. Aquatic Botany, 5, 301-327. Golterman, H. L. 1975

  4. Heavy metals in aquatic organisms of different trophic levels and their potential human health risk in Bohai Bay, China.

    PubMed

    Zhang, Yan; Lu, Xueqiang; Wang, Naili; Xin, Meinan; Geng, Shiwei; Jia, Jing; Meng, Qinghui

    2016-09-01

    Fourteen aquatic organism samples were collected from Bohai Bay, and concentrations of five heavy metals were measured to evaluate the pollution levels in aquatic organisms and the potential risk to human health. The concentrations of Zn and Cu were much higher than those of Cd, Cr, and Pb in all the organisms. In general, the heavy metal concentration levels were in the order phytoplankton < zooplankton < fish < shrimp < shellfish. Heavy metal concentrations in higher trophic-level aquatic organisms in Bohai Bay were compared to those in the organisms from other worldwide coastal waters. The concentration levels of most heavy metals were higher than the 75th percentile, except that Pb concentration was between the 25th and 50th percentiles. The calculated bioconcentration factors (BCF) of Cr, Cu, and Pb for phytoplankton were less than 100, indicating no accumulation in primary producers. The bioaccumulation factor (BAF) of Pb for zooplankton was the highest, indicating significant Pb accumulation in zooplankton. For higher trophic-level aquatic organisms, the order of BAF values was fish < shrimp < shellfish for most metals except for Pb. The human health risk assessment suggests that strict abatement measures of heavy metals must be taken to decrease the health risk caused by consuming aquatic products.

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

    PubMed

    Xu, Liang; Zhou, Zhen-Feng

    2017-03-08

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

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

    PubMed Central

    Xu, Liang; Zhou, Zhen-Feng

    2017-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Xu, Liang; Zhou, Zhen-Feng

    2017-03-01

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

  8. Preliminary Characterisation Of Proteins In Aquatic Samples: A Key To Understanding The Organic Nitrogen Cycle

    NASA Astrophysics Data System (ADS)

    Jones, V.; Ruddell, C. J.; Wainwright, G.; Jaffe, R.; Wolff, G. A.

    When discussing the nitrogen cycle, the dissolved organic nitrogen pool is often treated as a 'black box', due to the analytical difficulties associated with the character- isation of its components. Proteins contain a significant portion of the organic nitro- gen in aquatic systems and recent studies have suggested that certain protein species present in the aquatic environment are not as labile as it was originally thought (e.g. Suzuki et al., 1999) and may therefore form an important part of the long term nitro- gen cycle. The aim of this work is to apply extremely sensitive techniques, recently developed in the biochemical / biomedical field, to characterise proteins in aquatic samples. Two analytical approaches are followed: sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE) with silver staining and liquid chromatography mass spectrometry (peptide mapping). In this poster, we concentrate on SDS PAGE. Large volume water samples were collected at the Everglades National Park, Florida, which encompasses a wide array of ecosystems, ranging from freshwater canals to a shallow marine bay. Samples were concentrated and desalted by tangential flow filtration and proteins were isolated by repeated trichloroacetic acid precipitation. Leaf extracts of the dominant vegetation at each site were prepared. Application of SDS PAGE revealed a large number of distinct protein bands for all sites, corresponding to approximate molecular weights ranging from 30kDa to 250kDa. Protein distributions varied between sites, although bands corresponding to approximate molecular weights of 37kDa, 41kDa, 45kDa, 58kDa and 145kDa were ubiquitous. The 37kDa band in particular was also observed in all leaf extracts pre- pared, suggesting it may represent a recalcitrant molecule, which originates in the higher plant vegetation.

  9. The relationship between metal toxicity and biotic ligand binding affinities in aquatic and soil organisms: a review.

    PubMed

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

    2014-12-01

    The biotic ligand model (BLM) is a theoretical, potentially mechanistic approach to assess metal bioavailability in soil and aquatic systems. In a BLM, toxicity is linked to the fraction of biotic ligand occupied, which in turn, depends on the various components of the solution, including activity of the metal. Bioavailability is a key factor in determining toxicity and uptake of metals in organisms. In this study, the present status of BLM development for soil and aquatic organisms is summarized. For all species and all metals, toxicity was correlated with the conditional biotic ligand binding constants. For almost all organisms, values for Ag, Cu, and Cd were higher than those for Zn and Ni. The constants derived for aquatic systems seem to be equally valid for soil organisms, but in the case of soils, bioavailability from the soil solution is greatly influenced by the presence of the soil solid phase.

  10. The Life Cycle of Mercury Within the Clear Lake Aquatic Ecosystem: From Ore to Organism

    NASA Astrophysics Data System (ADS)

    Suchanek, T. H.; Suchanek, T. H.; Nelson, D. C.; Nelson, D. C.; Zierenberg, R. A.; King, P.; King, P.; McElroy, K.; McElroy, K.

    2001-12-01

    Clear Lake (Lake County) is located in the geologically active Clear Lake volcanics mercury (Hg) bearing Franciscan formation within the Coast Range of California, which includes over 300 abandoned Hg mines and prospects. Intermittent mining at the Sulphur Bank Mercury Mine (from 1872-1957), now a USEPA SuperFund site, has resulted in approximately 100 metric tonnes of Hg being deposited into the aquatic ecosystem of Clear Lake, with sediment concentrations of total-Hg as high as 650 mg/kg (parts per million = ppm) near the mine, making Clear Lake one of the most Hg contaminated lakes in the world. As a result, largemouth bass and other top predatory fish species often exceed both the Federal USFDA recommended maximum recommended concentrations of 1.0 ppm and the State of California level of 0.5 ppm. Acid rock drainage leaches Hg and high concentrations of sulfate from the mine site through wasterock and subsurface conduits through subsediment advection and eventually upward diffusion into lake sediments and water. When mineral-laden pH 3 fluids from the mine mix with Clear Lake water (pH 8), an alumino-silicate precipitate (floc) is produced that promotes the localized production of toxic methyl Hg. Floc "hot spots" in sediments near the mine exhibit low pH, high sulfate, anoxia and high organic loading which create conditions that promote Hg methylation by microbial activity, especially in late summer and fall. Wind-driven currents transport methyl-Hg laden floc particles throughout Clear Lake, where they are consumed by plankton and benthic invertebrates and bioaccumulated throughout the food web. While Clear Lake biota have elevated concentrations of methyl-Hg, they are not as elevated as might be expected based on the total Hg loading into the lake. A science-based management approach, utilizing over 10 years of data collected on Hg cycling within the physical and biological compartments of Clear Lake, is necessary to affect a sensible remediation plan.

  11. Role of chemical and ecological factors in trophic transfer of organic chemicals in aquatic food webs

    SciTech Connect

    Russell, R.W.; Gobas, F.A.P.C. . School of Resource and Environmental Management); Haffner, G.D. )

    1999-06-01

    Trophic transfer of chlorinated organic contaminants was investigated in an aquatic community composed of zooplankton, benthic invertebrates, and fish. Biomagnification, measured as the increase in lipid-based chemical concentrations in predator over that in prey, was observed for high-K[sub OW] chemicals (log K[sub OW] > 6.3). Low-K[sub OW] chemicals (log K[sub OW] < 5.5) did not biomagnify in the food web, and chemicals with log K[sub OW] between 5.5 and 6.3 showed some evidence of biomagnification. Trophic level differences in chemical accumulation in the food web could not be attributed to bioconcentration into increasing trophic levels with increasing lipid levels, as no relationship was observed between trophic position and lipid content of organisms. Plots of contaminant-ordinated principal component scores in component space predicted the detailed diets of the species examined. It is concluded that (1) trophic interactions play a crucial role in the distribution of high-K[sub OW] chemicals but not for low-K[sub OW] chemicals and that (2) contaminant distributions provide a means to determine structure in aquatic communities.

  12. Removal of terrestrial dissolved organic carbon in aquatic ecosystems of a temperate river network.

    NASA Astrophysics Data System (ADS)

    Wollheim, W. M.; Stewart, R. J.; Aiken, G.; Butler, K. D.; Morse, N.; Salisbury, J.

    2015-12-01

    Surface waters play an important role in the global carbon balance. Dissolved organic carbon (DOC) fluxes are a major transfer of terrestrial carbon to river systems, and the net removal of terrestrial DOC in aquatic systems is poorly constrained. We used a combination of spatially distributed sampling of three DOC fractions, nitrate, and chloride in streams of different size throughout a river network and modeling to quantify the net removal of terrestrial DOC relative to other constituents during a summer base flow period. The approach was applied to the 400 km2 Ipswich River watershed, MA, USA. We found that aquatic reactivity of terrestrial DOC leading to net loss is low, closer to conservative chloride than to reactive nitrogen. Net removal of DOC occurred mainly from the hydrophobic organic acid fraction, while hydrophilic and transphilic acids showed no net change. Model fits were improved using the different DOC fractions than when using bulk DOC, indicating that partitioning of bulk DOC into different fractions is critical for understanding terrestrial DOC removal. These findings suggest that river systems may have only a modest ability to alter the amounts of terrestrial DOC delivered to coastal zones.

  13. Evaluating the Relationship between Equilibrium Passive Sampler Uptake and Aquatic Organism Bioaccumulation.

    PubMed

    Joyce, Abigail S; Portis, Lisa M; Parks, Ashley N; Burgess, Robert M

    2016-11-01

    This Critcal Review evaluates passive sampler uptake of hydrophobic organic contaminants (HOCs) in water column and interstitial water exposures as a surrogate for organism bioaccumulation. Fifty-seven studies were found where both passive sampler uptake and organism bioaccumulation were measured and 19 of these investigations provided direct comparisons relating passive sampler uptake and organism bioaccumulation. Polymers compared included low-density polyethylene (LDPE), polyoxymethylene (POM), and polydimethylsiloxane (PDMS), and organisms ranged from polychaetes and oligochaetes to bivalves, aquatic insects, and gastropods. Regression equations correlating bioaccumulation (CL) and passive sampler uptake (CPS) were used to assess the strength of observed relationships. Passive sampling based concentrations resulted in log-log predictive relationships, most of which were within one to 2 orders of magnitude of measured bioaccumulation. Mean coefficients of determination (r(2)) for LDPE, PDMS, and POM were 0.68, 0.76, and 0.58, respectively. For the available raw, untransformed data, the mean ratio of CL and CPS was 10.8 ± 18.4 (n = 609). Using passive sampling as a surrogate for organism bioaccumulation is viable when biomonitoring organisms are not available. Passive sampling based estimates of bioaccumulation provide useful information for making informed decisions about the bioavailability of HOCs.

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

    PubMed

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

    2016-11-01

    With the projected increase in drought duration and intensity in future, small water bodies, and especially the terrestrial-aquatic interfaces, will be subjected to longer dry periods with desiccation of the sediment. Drought effects on the plant-sediment microorganism carbon continuum may disrupt the tight linkage between plants and microbes which governs sediment carbon and nutrient cycling, thus having a potential negative impact on carbon sequestration of small freshwater ecosystems. However, research on drought effects on the plant-sediment carbon transfer in aquatic ecosystems is scarce. We therefore exposed two emergent aquatic macrophytes, Phragmites australis and Typha latifolia, to a month-long summer drought in a mesocosm experiment. We followed the fate of carbon from leaves to sediment microbial communities with (13) CO2 pulse labelling and microbial phospholipid-derived fatty acid (PLFA) analysis. We found that drought reduced the total amount of carbon allocated to stem tissues but did not delay the transport. We also observed an increase in accumulation of (13) C-labelled sugars in roots and found a reduced incorporation of (13) C into the PLFAs of sediment microorganisms. Drought induced a switch in plant carbon allocation priorities, where stems received less new assimilates leading to reduced starch reserves whilst roots were prioritised with new assimilates, suggesting their use for osmoregulation. There were indications that the reduced carbon transfer from roots to microorganisms was due to the reduction of microbial activity via direct drought effects rather than to a decrease in root exudation or exudate availability.

  15. Acute toxicity of anionic and non-ionic surfactants to aquatic organisms.

    PubMed

    Lechuga, M; Fernández-Serrano, M; Jurado, E; Núñez-Olea, J; Ríos, F

    2016-03-01

    The environmental risk of surfactants requires toxicity measurements. As different test organisms have different sensitivity to the toxics, it is necessary to establish the most appropriate organism to classify the surfactant as very toxic, toxic, harmful or safe, in order to establish the maximum permissible concentrations in aquatic ecosystems. We have determined the toxicity values of various anionic surfactants ether carboxylic derivatives using four test organisms: the freshwater crustacean Daphnia magna, the luminescent bacterium Vibrio fischeri, the microalgae Selenastrum capricornutum (freshwater algae) and Phaeodactylum tricornutum (seawater algae). In addition, in order to compare and classify the different families of surfactants, we have included a compilation of toxicity data of surfactants collected from literature. The results indicated that V. fischeri was more sensitive to the toxic effects of the surfactants than was D. magna or the microalgae, which was the least sensitive. This result shows that the most suitable toxicity assay for surfactants may be the one using V. fischeri. The toxicity data revealed considerable variation in toxicity responses with the structure of the surfactants regardless of the species tested. The toxicity data have been related to the structure of the surfactants, giving a mathematical relationship that helps to predict the toxic potential of a surfactant from its structure. Model-predicted toxicity agreed well with toxicity values reported in the literature for several surfactants previously studied. Predictive models of toxicity is a handy tool for providing a risk assessment that can be useful to establish the toxicity range for each surfactant and the different test organisms in order to select efficient surfactants with a lower impact on the aquatic environment.

  16. Effects of magnesium, chromium, iron and zinc from food supplements on selected aquatic organisms.

    PubMed

    Bosnir, Jasna; Puntarić, Dinko; Cvetković, Zelimira; Pollak, Lea; Barusić, Lidija; Klarić, Ivana; Miskulin, Maja; Puntarić, Ida; Puntarić, Eda; Milosević, Milan

    2013-09-01

    The aim of this study was to determine the effect of uncontrolled environmental disposal of food supplements containing magnesium (Mg), chromium (Cr), iron (Fe) and zinc (Zn) on selected aquatic organisms including freshwater algae Scenedesmus subspicatus and Raphidocelis subcapitata, water flea Daphnia magna and duckweed Lemna minor. Thirty different food supplements containing Mg, Cr, Fe and Zn were analyzed. Results were expressed as effective concentration 50 (EC50), i.e. growth inhibiting Mg, Cr, Fe and Zn (mg/L) concentration immobilizing 50% of treated organisms. Particular metal EC50 differed significantly (p < 0.001) among study organisms, as follows (in ascending order): Scenedesmus subspicatus EC50 Fe (median 46.9 mg/L) < Zn (59.8 mg/L) < Mg (73.0 mg/L) < Cr (88.1 mg/L) (KW-H(3;120) = 36.856; p < 0.001); Raphidocelis subcapitata EC50 Fe (median 44.9 mg/L) < Zn (52.6 mg/L) < Mg (62.2 mg/L) < Cr (76.8 mg/L) (KW-H(3;120) = 44.0936; p < 0.001); Daphnia magna EC50 Zn (median 59.4 mg/L) < Cr (79.2 mg/L) < Fe (80.8 mg/L) Mg (82.0 mg/L) (KW-H(3;120) = 39.2637; p < 0.001); and Lemna minor EC50 Zn (median 131.0 mg/L) < Fe (186.8 mg/L) < Mg (192.5 mg/L) < Cr (240.4 mg/L) (KW-H(3;120) = 58.6567; p < 0.001). Uncontrolled environmental disposal of food supplements containing Mg, Cr, Fe and Zn exerts adverse effects on aquatic organisms. Therefore, legal provisions should regulate both the utilization and disposal of food supplements into the environment.

  17. Single and joint ecotoxicity data estimation of organic UV filters and nanomaterials toward selected aquatic organisms. Urban groundwater risk assessment.

    PubMed

    Molins-Delgado, Daniel; Gago-Ferrero, Pablo; Díaz-Cruz, M Silvia; Barceló, Damià

    2016-02-01

    The hazardous potential of organic UV filters (UV-Fs) is becoming an issue of great concern due to the widespread application of these compounds in most daily-use goods, such as hygiene and beauty products. Nanomaterials (NMs) have also been used in personal care products (PCPs) for many years. Nowadays, both classes of chemicals are considered environmental emerging contaminants. Despite some studies performed in vitro and in vivo reported adverse effects of many UV-Fs on the normal development of organisms, there is scarce data regarding acute and chronic toxicity. The aim of the present study was to determine the EC50 values of selected UV-Fs using standardised toxicity assays on three aquatic species i.e. Daphnia magna, Raphidocelis subcapitata and Vibrio fischeri. EC50 values obtained were in the mgl(-1) range for all the species. The estimated toxicity data allowed us to assess the environmental risk posed by selected UV-Fs in urban groundwater from Barcelona (Spain). The calculated ecological risk indicated a negligible impact on the aquifer. Giving the increasing importance of studying mixtures of pollutants and due to the widespread presence of nanomaterials (NMs) in the aquatic environment, other objective of this work was to explore the response on D. magna after exposure to both binary combinations of UV-Fs among them and UV-F with NMs. In all cases but the nano-silver mixtures, joint toxicity was mitigated or even eradicated.

  18. Helminths and protozoans of aquatic organisms as bioindicators of chemical pollution.

    PubMed

    Vidal Martínez, V M

    2007-09-01

    There is no doubt that the aquatic environments receive large quantities of chemicals as consequence of human activities and that those substances have a detrimental effect on human health. Despite the obvious need for effective disposal of these substances, we need to understand and prevent the outcome of harmful environmental exposures. Thus, we need biomarkers and bioindicators to advance our understanding to these harmful exposures and their biological effects. In the last three decades a large number of publications has suggested that aquatic organisms and their parasites (mainly helminths and ciliate protozoans) are useful bioindicators of chemical pollution. However, the main weakness of this approach is that after exposure the population size of these parasites can increase or decrease without a consistent pattern. I suggest that this is in part due to the lack of focus on the correct spatial or temporal scales at which the environment is acting over our study object. Thus, I propose to use spatially explicit (= georeferenced) data for determining whether there is spatial structure in our study area. Spatial structure is the tendency of nearby samples to have attribute values more similar than those farther apart. These attributes are shaped by environmental variables acting at specific spatial and temporal scales. Thus, I suggest to consider these tools for determining the correct spatial or temporal scales of study, but also to record pollutant concentrations, bioindicators, biomarkers and parasites at individual host level. Combining this information with long-term monitoring programs is likely to improve our understanding of the effects of chemical pollutants over the aquatic environments.

  19. Effects of Outreach on the Prevention of Aquatic Invasive Species Spread among Organism-in-Trade Hobbyists.

    PubMed

    Seekamp, Erin; Mayer, Jessica E; Charlebois, Patrice; Hitzroth, Greg

    2016-11-01

    Releases of aquatic organisms-in-trade by aquarists, water gardeners, and outdoor pond owners have been identified as aquatic invasive species vectors within the Laurentian Great Lakes region. The trademarked U.S. Fish and Wildlife Service Habitattitude campaign was developed in 2004 to encourage self-regulation by these groups, but little is known about its effects. We surveyed organisms-in-trade hobbyists in the eight Great Lakes states (Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin, USA) to assess their recognition of the Habitattitude campaign and their compliance with the campaign's recommended behaviors for organism purchase and disposal. Awareness of the Habitattitude campaign was low, but hobbyists that identified as both water gardeners and aquarium hobbyists were more aware of the campaign than individuals who participated in one of those hobbies. Engaged hobbyists (high aquatic invasive species awareness, concern, and knowledge) were significantly more likely than passive hobbyists (low aquatic invasive species awareness, concern, and knowledge) to make decisions about disposal of live organisms with the intention of preventing aquatic invasive species spread, were more likely to contact other hobbyists for disposal and handling advice, and were less likely to contact professionals, such as retailers. On the basis of our results, we suggest that compliance with recommended behaviors may be increased by fostering hobbyist networks; creating materials that both explain tangible, negative environmental impacts and list specific prevention behaviors; and disseminating these materials through trusted information sources and venues.

  20. Effects of Outreach on the Prevention of Aquatic Invasive Species Spread among Organism-in-Trade Hobbyists

    NASA Astrophysics Data System (ADS)

    Seekamp, Erin; Mayer, Jessica E.; Charlebois, Patrice; Hitzroth, Greg

    2016-11-01

    Releases of aquatic organisms-in-trade by aquarists, water gardeners, and outdoor pond owners have been identified as aquatic invasive species vectors within the Laurentian Great Lakes region. The trademarked U.S. Fish and Wildlife Service Habitattitude campaign was developed in 2004 to encourage self-regulation by these groups, but little is known about its effects. We surveyed organisms-in-trade hobbyists in the eight Great Lakes states (Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin, USA) to assess their recognition of the Habitattitude campaign and their compliance with the campaign's recommended behaviors for organism purchase and disposal. Awareness of the Habitattitude campaign was low, but hobbyists that identified as both water gardeners and aquarium hobbyists were more aware of the campaign than individuals who participated in one of those hobbies. Engaged hobbyists (high aquatic invasive species awareness, concern, and knowledge) were significantly more likely than passive hobbyists (low aquatic invasive species awareness, concern, and knowledge) to make decisions about disposal of live organisms with the intention of preventing aquatic invasive species spread, were more likely to contact other hobbyists for disposal and handling advice, and were less likely to contact professionals, such as retailers. On the basis of our results, we suggest that compliance with recommended behaviors may be increased by fostering hobbyist networks; creating materials that both explain tangible, negative environmental impacts and list specific prevention behaviors; and disseminating these materials through trusted information sources and venues.

  1. The mode of action of isocyanide in three aquatic organisms, Balanus amphitrite, Bugula neritina and Danio rerio.

    PubMed

    Zhang, Yi-Fan; Kitano, Yoshikazu; Nogata, Yasuyuki; Zhang, Yu; Qian, Pei-Yuan

    2012-01-01

    Isocyanide is a potential antifouling compound in marine environments. In this study, we investigated its mode of action in three aquatic organisms. Two of them, the bryozoan Bugula neritina and the barnacle Balanus amphitrite, are major marine fouling invertebrates, and the other organism is the non-target species zebrafish Danio rerio. In the swimming larvae of B. neritina, isocyanide did not affect the total attachment rate (≤50 µg ml(-1)), but it did change the attachment site by increasing the percentage of attachment on the bottom of the container rather than on the wall or air-water inter-surface. Isocyanide binds several proteins in B. neritina as identified via SDS-PAGE-LC-MS/MS: 1) a 30 kD protein band containing two proteins similar to voltage dependent anion channels (VDAC), which control the direct coupling of the mitochondrial matrix to the energy maintenance of the cytosol and the release of apoptogenic factors from mitochondria of mammalian cells; and 2) an unknown 39 kD protein. In B. amphitrite cyprids, the isocyanide binding protein were 1) a protein similar to NADH-ubiquinone oxidoreductase, which is the "entry enzyme" of oxidative phosphorylation in mitochondria; and 2) cytochrome P450. In Danio rerio embryos, isocyanide caused "wavy" notochords, hydrocephalus, pericardial edema, poor blood circulation, and defects in pigmentation and hematopoiesis, which phenocopied copper deficiency. This is the first report on isocyanide binding proteins in fouling organisms, as well as the first description of its phenotype and potential toxicology in zebrafish.

  2. FROM ORGANISMS TO POPULATIONS: MODELING AQUATIC TOXICITY DATA ACROSS TWO LEVELS OF BIOLOGICAL ORGANIZATION.

    EPA Science Inventory

    A critical step in estimating the ecological effects of a toxicant is extrapolating organism-level response data across higher levels of biological organization. In the present study, the organism-to-population link is made for the mysid, Americamysis bahia, exposed to a range of...

  3. Toxicity of pentachlorophenol to aquatic organisms under naturally varying and controlled environmental conditions

    SciTech Connect

    Hedtke, S.F.; West, C.W.; Allen, K.N.; Norberg-King, T.J.; Mount, D.I.

    1986-06-01

    The toxicity of pentachlorophenol (PCP) was determined in the laboratory for 11 aquatic species. Tests were conducted seasonally in ambient Mississippi River water and under controlled conditions in Lake Superior water. Fifty-one acute toxicity tests were conducted, with LC50 values ranging from 85 micrograms/L for the white sucker Catastomus commersoni during the summer to greater than 7770 micrograms/L for the isopod Asellus racovitzai during the winter. The effect of PCP on growth and/or reproduction was determined for seven species. The most sensitive chronically exposed organisms were the cladoceran Ceriodaphnia reticulata and the snail Physa gyrina. The greatest variation in toxicity was due to species sensitivity. Within a given, season there was as much as a 40-fold difference in LC50 values between species. For any one species, the maximum variation in LC50 between seasons was approximately 14-fold. There were also substantial differences in acute-chronic relationships, with acute/chronic ratios ranging from greater than 37 for C. reticulata to 1 for Simocephalus vetulus. It is suggested that the composition of the aquatic community should be the most important consideration in estimating the potential environmental effects of PCP.

  4. Potential risks to freshwater aquatic organisms following a silvicultural application of herbicides in Oregon's Coast Range.

    PubMed

    Louch, Jeff; Tatum, Vickie; Allen, Ginny; Hale, V Cody; McDonnell, Jeffrey; Danehy, Robert J; Ice, George

    2017-03-01

    Glyphosate, aminomethylphosphonic acid (AMPA), imazapyr, sulfometuron methyl (SMM), and metsulfuron methyl (MSM) were measured in streamwater collected during and after a routine application of herbicides to a forestry site in Oregon's Coast Range. Samples were collected at 3 stations: HIGH at the fish-no-fish interface in the middle of the harvest and spray unit, MID at the bottom of the unit, and LOW downstream of the unit. All herbicides were applied by helicopter in a single tank mix. AMPA, imazapyr, SMM, and MSM were not detected (ND) in any sample at 15, 600, 500, and 1000 ng/L, respectively. A pulse of glyphosate peaking at approximately equal to 62 ng/L manifested at HIGH during the application. Glyphosate pulses peaking at 115 ng/L (MID) and 42 ng/L (HIGH) were found during the first 2 postapplication storm events 8 and 10 days after treatment (DAT), respectively: glyphosate was less than 20 ng/L (ND) at all stations during all subsequent storm events. All glyphosate pulses were short-lived (4-12 h). Glyphosate in baseflow was approximately equal to 25 ng/L at all stations 3 DAT and was still approximately equal to 25 ng/L at HIGH, but ND at the other stations, 8 DAT: subsequently, glyphosate was ND in baseflow at all stations. Aquatic organisms were subjected to multiple short-duration, low-concentration glyphosate pulses corresponding to a cumulative time-weighted average (TWA) exposure of 6634 ng/L × h. Comparisons to TWA exposures associated with a range of toxicological endpoints for sensitive aquatic organisms suggests a margin of safety exceeding 100 at the experimental site, with the only potential exception resulting from the ability of fish to detect glyphosate via olfaction. For imazapyr, SMM, and MSM the NDs were at concentrations low enough to rule out effects on all organisms other than aquatic plants, and the low concentration and (assumed) pulsed nature of any exposure should mitigate this potential. Integr Environ

  5. Do affective attitudes predict organ donor registration? A prospective study.

    PubMed

    Shepherd, Lee; O'Carroll, Ronan E

    2014-10-01

    This study assessed whether people's affective attitudes predicted organ donor registration at a later time. People who were not registered as an organ donor prior to completing the study (N = 150) first rated their affective attitudes towards organ donation. We then measured whether they clicked on a hyperlink to register as an organ donor. Believing that the body should be kept whole for burial (bodily integrity) was the only affective attitude to predict this organ donation behaviour. Future campaigns should target this concern in order to increase organ donor registration and the availability of donor organs.

  6. The effect of organism density on bioaccumulation of contaminants from sediment in three aquatic test species: a case for standardizing to sediment organic carbon.

    PubMed

    Van Geest, J L; Poirier, D G; Solomon, K R; Sibley, P K

    2011-05-01

    Laboratory methods for measuring bioaccumulation of organic contaminants from sediment into aquatic organisms continue to improve, but some aspects are still in need of standardization. From a review of published methods, we noted that the loading density of organisms was determined inconsistently and was primarily based on either sediment volume or total organic carbon (TOC). The rationale mainly expressed for standardizing to TOC was to minimize the depletion of sediment contaminants. However, even when density was standardized to TOC, the relative amount of TOC provided (i.e., ratio of TOC to organism dry weight [dw]) was highly variable. In this study, we examined the effect of organism density (standardized to sediment TOC or volume) on bioaccumulation in three freshwater organisms. The oligochaete Lumbriculus variegatus, mayfly nymph Hexagenia spp., and fathead minnow Pimephales promelas were exposed for 28 days to two field-contaminated sediments that varied in concentration of PCBs and TOC. Densities tested were 50:1 and 27:1 ratios of TOC to organism dw and 140 ml sediment/g wet weight (ww) biomass, yielding low to high organism densities. Bioaccumulation in Hexagenia spp. was significantly higher at the lowest organism density compared with the highest organism density when exposed to site 2 sediment (1.1% TOC) but only with tissue concentrations expressed on a ww basis. Otherwise, there was no significant effect of density on bioaccumulation in organisms exposed to sediments from site 1 (12% TOC) or site 2. Survival of Hexagenia spp. was adversely affected at the highest organism density when the relative amount of TOC was low. The results of this study support the recommendation of standardizing organism density relative to a particular amount of TOC for invertebrate species. A 27:1 ratio of TOC:organism dw was selected as a standard organism density for a new bioaccumulation method because survival, growth, and bioaccumulation were not impacted

  7. Assessment of relative accuracy in the determination of organic matter concentrations in aquatic systems

    USGS Publications Warehouse

    Aiken, G.; Kaplan, L.A.; Weishaar, J.

    2002-01-01

    Accurate determinations of total (TOC), dissolved (DOC) and particulate (POC) organic carbon concentrations are critical for understanding the geochemical, environmental, and ecological roles of aquatic organic matter. Of particular significance for the drinking water industry, TOC measurements are the basis for compliance with US EPA regulations. The results of an interlaboratory comparison designed to identify problems associated with the determination of organic matter concentrations in drinking water supplies are presented. The study involved 31 laboratories and a variety of commercially available analytical instruments. All participating laboratories performed well on samples of potassium hydrogen phthalate (KHP), a compound commonly used as a standard in carbon analysis. However, problems associated with the oxidation of difficult to oxidize compounds, such as dodecylbenzene sulfonic acid and caffeine, were noted. Humic substances posed fewer problems for analysts. Particulate organic matter (POM) in the form of polystyrene beads, freeze-dried bacteria and pulverized leaf material were the most difficult for all analysts, with a wide range of performances reported. The POM results indicate that the methods surveyed in this study are inappropriate for the accurate determination of POC and TOC concentration. Finally, several analysts had difficulty in efficiently separating inorganic carbon from KHP solutions, thereby biasing DOC results.

  8. Molecular weight distribution of phosphorus fraction of aquatic dissolved organic matter.

    PubMed

    Ged, Evan C; Boyer, Treavor H

    2013-05-01

    This study characterized dissolved organic phosphorus (DOP) that is discharged from the Everglades Agricultural Area as part of the larger pool of aquatic dissolved organic matter (DOM). Whole water samples collected at the Everglades stormwater treat area 1 West (STA-1 W) were fractionated using a batch ultrafiltration method to separate organic compounds based on apparent molecular weight (AMW). Each AMW fraction of DOM was characterized for phosphorus, carbon, nitrogen, UV absorbance, and fluorescence. The DOP content of the Everglades water matrix was characteristically variable constituting 4-56% of total phosphorus (TP) and demonstrated no correlation with dissolved organic carbon (DOC). Measured values for DOP exceeded 14μgL(-1) in four out of five sampling dates making phosphorus load reductions problematic for the stormwater treatment areas (STAs), which target inorganic phosphorus and have a goal of 10μgL(-1) as TP. The molecular weight distributions revealed 40% of DOP is high molecular weight, aromatic-rich DOM. The results of this research are expected to be of interest to environmental chemists, environmental engineers, and water resources managers because DOP presents a major obstacle to achieving TP levels <10μgL(-1).

  9. Thermal effects on aquatic organisms: an annotated bibliography of the 1978 literature

    SciTech Connect

    Talmage, S.S.

    1980-01-01

    This bibliography, containing 457 references from the 1978 literature, is the eighth in a series of annotated bibliographies on the effects of heat on aquatic organisms. The effects of thermal discharges at power plant sites are emphasized. Laboratory and field studies on temperature tolerance and the effects of temperature changes on reproduction, development, growth, distribution, physiology, and sensitivity to other stresses are included. References in the bibliography are divided into three subject categories: marine sytems, freshwater systems, and estuaries. The references are arranged alphabetically by first author. Indexes are provided for author, keywords, subject category, geographic location of the study, taxon, and title (alphabetical listing of keywords-in-context of nontrivial words in the title).

  10. Structural and functional effects of herbicides on non-target organisms in aquatic ecosystems with an emphasis on atrazine

    USGS Publications Warehouse

    Fairchild, James; Kortekamp, Andreas

    2011-01-01

    Agricultural production accounts for approximately 90% of herbicide use in the U.S. (Kiely et al., 2004). Gianessi and Reigner (2007) indicated that herbicides are routinely used on more than 90% of the area designated for large commercial crops including corn, soybeans, cotton, sugar beets, peanuts, and rice. Increased farm mechanization, technological advancements in production of inexpensive sources of inorganic nitrogen fertilizer (e.g., anhydrous ammonia), and conversion of forest, grassland, and wetland habitats to cropland has led to a tremendous increase in global food production over the past half-century. Herbicides have augmented advances in large-scale agricultural systems and have largely replaced mechanical and hand-weeding control mechanisms (Gianessi and Reigner, 2007). The wide-spread use of herbicides in agriculture has resulted in frequent chemical detections in surface and groundwaters (Gilliom, 2007). The majority of herbicides used are highly water soluble and are therefore prone to runoff from terrestrial environments. In additon, spray drift and atmospheric deposition can contribute to herbicide contamination of aquatic environments. Lastly, selected herbicides are deliberately applied to aquatic environments for controlling nuisance aquatic vegetation. Although aquatic herbicide exposure has been widely documented, these exposures are not necessarily related to adverse non-target ecological effects on natural communities in aquatic environments. This chapter evaluates the potential for effects of herbicides on the structure and function of aquatic envrionments at the population, community, and ecosystem levels of biological organization. In this manuscript I examine several critical aspects of the subject matter area: primary herbicides in use and chemical modes of action; the regulatory process used for registration and risk assessment of herbicides; data regarding non-target risks and the relative sensitivity of aquatic plants

  11. Effects of aqueous soil-biochar extracts on representative aquatic organisms: a first evaluation

    NASA Astrophysics Data System (ADS)

    Bastos, A. C.; Abrantes, N.; Prodana, M.; Verheijen, F.; Keizer, J. J.; Soares, A. M. V. M.; Loureiro, S.

    2012-04-01

    Increasing considerations of biochar application to soils has raised concerns over implications to overall environmental quality, associated to some of its components. The heterogeneity of biochar composition is well documented in relation to co-existing chemical species, as a function of feedstock and pyrolysis conditions. Robust ecotoxicology studies with focus on bioavailable biochar components in soil remain scarce and have only started to emerge. This pilot study provides an insight into the potential ecotoxicological effects of aqueous extracts of biochar-amended soil on a range of aquatic organisms (Vibrio fischeri, Pseudokirchneriella subcapitata and Daphnia magna), using a battery of standard aquatic bioassays. The use of such bioassays in environmental risk assessment of soil-biochar elutriates is here suggested as a crucial tool, to bridge the gap between biochar's 'inert' fraction in soil and that bioavailable to edaphic organisms. Aqueous extracts were obtained from LUFA 2.2 standard soil (control) and following amendment with pine biochar at common field application rates (80 ton ha-1). Acute exposure to soil-biochar extracts allowed estimating toxicity parameters and developing dose-response curves for all tested species, through well-established methodological guidelines. The bioluminescent bacteria V. fischeri showed negligible EC50 (effect concentration corresponding to 50% luminescence decline) values in the MICROTOX® basic test (independent of exposure time), suggesting low susceptibility to soil-biochar extracts. Mild toxicity was also observed in the microalgae P. subcapitata growth inhibition test, where significant deleterious effects on growth rate occurred only at the highest (100%) extract concentration (p<0.05). Among the tested species, toxicity was generally more marked in the primary consumer D. magna, with an EC50 (effect concentration corresponding to 50% immobilisation) of 2.95%. The pattern and extent of observed effects were

  12. Organochlorine and metal pollution in aquatic organisms sampled in the Donana National Park during the period 1983-1986

    SciTech Connect

    Rico, M.C.; Hernandez, L.M.; Gonzalez, M.J.; Fernandez, M.A.; Montero, M.C.

    1987-12-01

    The study area, Donana National Park, is located in the South South-West of Spain, and this is one of the most important reservation of Europe. Samples of aquatic organism were obtained from the principal waterway of Donana National Park to determine the degree of organochlorine and metal contamination of this environment. The sampling was carried out during the period 1983-1986 in order to collect six aquatic species in four sites along the Brazo de la Torre. An agricultural area in the North-West side of the Park and a working mine at about 40 km from its northern boundary were considered as the likely main polluting sources of organochlorine pesticides, PCBs, and heavy metals respectively. The aquatic organism species chosen for analysis were: American crayfish (Procambarus clarckii), carp (Cyprinus carpio), barbel (Barbus barbus), grey mullet (Mugil capito), eel (Anguilla anguilla), and frog (Rana perezi).

  13. Toxicity on aquatic organisms exposed to secondary effluent disinfected with chlorine, peracetic acid, ozone and UV radiation.

    PubMed

    da Costa, Juliana Berninger; Rodgher, Suzelei; Daniel, Luiz Antonio; Espíndola, Evaldo Luiz Gaeta

    2014-11-01

    The toxic potential of four disinfectant agents (chlorine, ozone, peracetic acid and UV radiation), used in the disinfection of urban wastewater, was evaluated with respect to four aquatic organisms. Disinfection assays were carried out with wastewater from the city of Araraquara (São Paulo State, Brazil), and subsequently, toxicity bioassays were applied in order to verify possible adverse effects to the cladocerans (Ceriodaphnia silvestrii and Daphnia similis), midge larvae Chironomus xanthus and fish (Danio rerio). Under the experimental conditions tested, all the disinfectants were capable of producing harmful effects on the test organisms, except for C. xanthus. The toxicity of the effluent to C. silvestrii was observed to increase significantly as a result of disinfection using 2.5 mg L(-1) chlorine and 29.9 mg L(-1) ozone. Ozonation and chlorination significantly affected the survival of D. similis and D. rerio, causing mortality of 60 to 100 % in comparison to the non-disinfected effluent. In experiments with effluent treated with peracetic acid (PAA) and UV radiation, a statistically significant decrease in survival was only detected for D. rerio. This investigation suggested that the study of the ideal concentrations of disinfectants is a research need for ecologically safe options for the treatment of wastewater.

  14. A Review of the Tissue Residue Approach for Organic and Organometallic Compounds in Aquatic Organisms

    EPA Science Inventory

    This paper reviews the tissue residue approach (TRA) for toxicity assessment as it applies to organic chemicals and some organometallic compounds (tin, mercury, and lead). Specific emphasis was placed on evaluating key factors that influence interpretation of critical body resid...

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

    USGS Publications Warehouse

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

    2009-01-01

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

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

    USGS Publications Warehouse

    Larsen, L.G.; Harvey, J.W.; Noe, G.B.; Crimaldi, J.P.

    2009-01-01

    Transport of particulate organic material can impact watershed sediment and nutrient budgets and can alter the geomorphologic evolution of shallow aquatic environments. Prediction of organic aggregate ("floc") transport in these environments requires knowledge of how hydraulics and biota affect the entrainment, settling, and aggregation of particles. This study evaluated the aggregation and field transport dynamics of organic floc from a low-gradient floodplain wetland with flow-parallel ridges and sloughs in the Florida Everglades. floc dynamics were evaluated in a rotating annular flume and in situ in the field. Under present managed conditions in the Everglades, floc is not entrained by mean flows but is suspended via biological production in the water column and bioturbation. Aggregation was a significant process affecting Everglades floc at high flume flow velocities (7.0 cm s-1) and during recovery from high flow; disaggregation was not significant for the tested flows. During moderate flows when floc dynamics are hydrodynamically controlled, it is possible to model floc transport using a single "operative floc diameter" that accurately predicts fluxes downstream and to the bed. In contrast, during high flows and recovery from high flows, aggregation dynamics should be simulated. When entrained by flow in open-water sloughs, Everglades floc will be transported downstream in multiple deposition and reentrainment events but will undergo net settling when transported onto ridges of emergent vegetation. We hypothesize that net transport of material from open to vegetated areas during high flows is critical for forming and maintaining distinctive topographic patterning in the Everglades and other low-gradient floodplains. Copyright 2009 by the American Geophysical Union.

  17. Development of a passive, in situ, integrative sampler for hydrophilic organic contaminants in aquatic environments.

    PubMed

    Alvarez, David A; Petty, Jimmie D; Huckins, James N; Jones-Lepp, Tammy L; Getting, Dominic T; Goddard, Jon P; Manahan, Stanley E

    2004-07-01

    Increasingly it is being realized that a holistic hazard assessment of complex environmental contaminant mixtures requires data on the concentrations of hydrophilic organic contaminants including new generation pesticides, pharmaceuticals, personal care products, and many chemicals associated with household, industrial, and agricultural wastes. To address this issue, we developed a passive in situ sampling device (the polar organic chemical integrative sampler [POCIS]) that integratively concentrates trace levels of complex mixtures of hydrophilic environmental contaminants, enables the determination of their time-weighted average water concentrations, and provides a method of estimating the potential exposure of aquatic organisms to the complex mixture of waterborne contaminants. Using a prototype sampler, linear uptake of selected herbicides and pharmaceuticals with log K(ow)s < 4.0 was observed for up to 56 d. Estimation of the ambient water concentrations of chemicals of interest is achieved by using appropriate uptake models and determination of POCIS sampling rates for appropriate exposure conditions. Use of POCIS in field validation studies targeting the herbicide diuron in the United Kingdom resulted in the detection of the chemical at estimated concentrations of 190 to 600 ng/L. These values are in agreement with reported levels found in traditional grab samples taken concurrently.

  18. Toxicity of sediments near an aluminum smelter on the St. Lawrence river to aquatic organisms

    SciTech Connect

    Metcalfe-Smith, J.L.; Sirota, G.R.; Holtze, K.E.; Reid, J.J.

    1994-12-31

    Under a US EPA Superfund Administrative Order, over 50,000 cu yds of bottom sediments contaminated with fluoride, cyanide, PCBs, PAHs and Al will be dredged from the St. Lawrence River near the Reynolds Metals plant at Massena, NY in 1994. The purpose of this study was to determine the toxicity of these sediments to aquatic organisms and the potential for remobilizing sediment-bound contaminants into the water column during dredging. Sediment was collected from 7 sites along a gradient from the outfall in October 1993. Sediment from the most contaminated site ``B2`` (1,500 {mu}g/g fluoride, 30 {mu}g/g cyanide, 450 {mu}g/g PCBs, 3,500 {mu}g/g PAHs, 90,000 {mu}g/g Al), caused complete mortality of mayflies, Hexagenia limbata, and avoidance, considerable weight loss and some mortality in fathead minnows, Pimephales promelas, after 21 d exposure. Mortality was not observed at other sites, but growth of both organisms decreased with increasing contamination. LOECs of B2 elutriate were 13% for survival and reproduction of Ceriodaphnia dubia, and 6% for survival and 1.5% for growth of larval fatheads. Elutriates of other sediments were nontoxic. TIE testing suggested organic contaminants as the primary toxicants. Over 2,000 cu yds of sediment are highly toxic and 18,000 cu yds somewhat toxic. Toxicity of B2 elutriate shows that contaminants enter the water column when sediments are disturbed and may harm indigenous biota.

  19. Development of a passive, in situ, integrative sampler for hydrophilic organic contaminants in aquatic environments

    USGS Publications Warehouse

    Alvarez, D.A.; Petty, J.D.; Huckins, J.N.; Jones-Lepp, T. L.; Getting, D.T.; Goddard, J.P.; Manahan, S.E.

    2004-01-01

    Increasingly it is being realized that a holistic hazard assessment of complex environmental contaminant mixtures requires data on the concentrations of hydrophilic organic contaminants including new generation pesticides, pharmaceuticals, personal care products, and many chemicals associated with household, industrial, and agricultural wastes. To address this issue, we developed a passive in situ sampling device (the polar organic chemical integrative sampler [POCIS]) that integratively concentrates trace levels of complex mixtures of hydrophilic environmental contaminants, enables the determination of their time-weighted average water concentrations, and provides a method of estimating the potential exposure of aquatic organisms to the complex mixture of waterborne contaminants. Using a prototype sampler, linear uptake of selected herbicides and pharmaceuticals with log KowS < 4.0 was observed for up to 56 d. Estimation of the ambient water concentrations of chemicals of interest is achieved by using appropriate uptake models and determination of POCIS sampling rates for appropriate exposure conditions. Use of POCIS in field validation studies targeting the herbicide diuron in the United Kingdom resulted in the detection of the chemical at estimated concentrations of 190 to 600 ng/L. These values are in agreement with reported levels found in traditional grab samples taken concurrently.

  20. INTERSPECIES CORRELATION ESTIMATION (ICE) FOR ACUTE TOXICITY TO AQUATIC ORGANISMS AND WILDLIFE. II. USER MANUAL AND SOFTWARE

    EPA Science Inventory

    Asfaw, Amha, Mark R. Ellersieck and Foster L. Mayer. 2003. Interspecies Correlation Estimations (ICE) for Acute Toxicity to Aquatic Organisms and Wildlife. II. User Manual and Software. EPA/600/R-03/106. U.S. Environmental Protection Agency, National Health and Environmental Effe...

  1. sAC from aquatic organisms as a model to study the evolution of acid/base sensing.

    PubMed

    Tresguerres, Martin

    2014-12-01

    Soluble adenylyl cyclase (sAC) is poised to play multiple physiological roles as an acid/base (A/B) sensor in aquatic organisms. Many of these roles are probably similar to those in mammals; a striking example is the evolutionary conservation of a mechanism involving sAC, carbonic anhydrase and vacuolar H⁺-ATPase that acts as a sensor system and regulator of extracellular A/B in shark gills and mammalian epididymis and kidney. Additionally, the aquatic environment presents unique A/B and physiological challenges; therefore, sACs from aquatic organisms have likely evolved distinct kinetic properties as well as distinct physiological roles. sACs from aquatic organisms offer an excellent opportunity for studying the evolution of A/B sensing at both the molecular and whole organism levels. Moreover, this information could help understand and predict organismal responses to environmental stress based on mechanistic models.This article is part of a Special Issue entitled "The Role of Soluble Adenylyl Cyclase in Health and Disease," guest edited by J. Buck and L. R. Levin.

  2. Bayesian approach to potency estimation for aquatic toxicology experiments when a toxicant affects both fecundity and survival.

    PubMed

    Zhang, Jing; Bailer, A John; Oris, James T

    2012-08-01

    Chemicals in aquatic systems may impact a variety of endpoints including mortality, growth, or reproduction. Clearly, growth or reproduction will only be observed in organisms that survive. Because it is common to observe mortality in studies focusing on the reproduction of organisms, especially in higher concentration conditions, the resulting observed numbers of young become a mixture of zeroes and positive counts. Zeroes are recorded for organisms that die before having any young and living organisms with no offspring. Positive counts are recorded for living organisms with offspring. Thus, responses reflect both fecundity and mortality of the organisms used in such tests. In the present study, the authors propose the estimation of the concentration associated with a specified level of reproductive inhibition (RIp) using a Bayesian zero-inflated Poisson (ZIP) regression model. This approach allows any prior information and expert knowledge about the model parameters to be incorporated into the regression coefficients or RIp estimation. Simulation studies are conducted to compare the Bayesian ZIP regression model and classical methods. The Bayesian estimator outperforms the frequentist alternative by producing more precise point estimates with smaller mean square differences between RIp estimates and true values, narrower interval estimates with better coverage probabilities. The authors also applied their proposed model to a study of Ceriodaphnia dubia exposed to a test toxicant.

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

    SciTech Connect

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

    2007-07-15

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

  4. Evaluation of OECD guidelines for testing of chemicals with aquatic organisms

    SciTech Connect

    Blaylock, B.G.; McCarthy, J.F.; Frank, M.L.; Singley, P.T.

    1983-10-01

    The protocols in the OECD (Organization for Economic Cooperation and Development) guidelines for testing of chemicals with aquatic organisms were evaluated for the following tests: (1) Fish, Acute Toxicity Test, (2) Bioaccumulation: Flow-through Fish Test, (3) Daphnia sp., 14-day Reproduction Test (including an Acute Immobilization Test), and (4) Alga, Growth Inhibition Test. The protocols were evaluated by conducting the tests with different classes of chemicals (i.e., water soluble, less water soluble requiring a chemical carrier, and volatile chemical). Flow-through and semistatic Fish, Acute Toxicity Tests were conducted with cupric chloride and acridine. The Bioaccumulation Flow-Through Fish Test was conducted with naphthalene and DDE. Three chemicals - cupric chloride, acridine, and di-n-butyl phthalate - were used to evaluate the Daphnia sp., 14-day Reproduction Test. The Alga, Growth Inhibition Test was evaluated with three chemicals: cupric chloride, acridine, and paradichlorobenzene. By following the OECD guidelines in conducting these tests, results were obtained that are comparable with literature data obtained with other methods. An evaluation of each test protocol is given with recommendations for the guidelines for conducting the tests.

  5. Role of exposure mode in the bioavailability of triphenyl phosphate to aquatic organisms

    USGS Publications Warehouse

    Huckins, James N.; Fairchild, James F.; Boyle, Terence P.

    1991-01-01

    A laboratory study was conducted to investigate the role of the route of triphenyl phosphate (TPP) entry on its aquatic bioavailability and acute biological effects. Three TPP treatments were used for exposures of fish and invertebrates. These consisted of TPP dosed directly into water with and without clean sediment and TPP spiked onto sediment prior to aqueous exposures. Results of static acute toxicity tests (no sediment) were 0.78 mg/L (96-h LC50) for bluegill, 0.36 mg/L (48-h EC50) for midge, and 0.25 mg/L (96-h EC50) for scud. At 24 h, the sediment (1.1% organic carbon)/water partition coefficient (Kp) for TPP was 112. Use of this partition coefficient model to predict the sediment-mediated reduction of TPP concentration in water during toxicity tests resulted in a value that was only 10% less than the nominal value. However, the required nominal concentration of TPP to cause acute toxicity responses in test organisms was significantly higher than the predicted value by the model for both clay and soil-derived sediment. Direct spiking of TPP to soil minimized TPP bioavailability. Data from parallel experiments designed to track TPP residues in water through time suggest that sorption kinetics control residue bioavailability in the initial 24 h of exposure and may account for observed differences in LC50 and EC50 values from the sediment treatments.

  6. Plastic as a carrier of POPs to aquatic organisms: a model analysis.

    PubMed

    Koelmans, Albert A; Besseling, Ellen; Wegner, Anna; Foekema, Edwin M

    2013-07-16

    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 sorption of POPs to plastic (POP "dilution"), increased bioaccumulation by ingestion of plastic-containing POPs ("carrier"), and decreased bioaccumulation by ingestion of clean plastic ("cleaning"). The model is parametrized for the lugworm Arenicola marina and evaluated against recently published bioaccumulation data for this species from laboratory bioassays with polystyrene microplastic. Further scenarios include polyethylene microplastic, nanosized plastic, and open marine systems. Model analysis shows that plastic with low affinity for POPs such as polystyrene will have a marginal decreasing effect on bioaccumulation, governed by dilution. For stronger sorbents such as polyethylene, the dilution, carrier, and cleaning mechanism are more substantial. In closed laboratory bioassay systems, dilution and cleaning dominate, leading to decreased bioaccumulation. Also in open marine systems a decrease is predicted due to a cleaning mechanism that counteracts biomagnification. However, the differences are considered too small to be relevant from a risk assessment perspective.

  7. Unexpected toxicity to aquatic organisms of some aqueous bisphenol A samples treated by advanced oxidation processes.

    PubMed

    Tišler, Tatjana; Erjavec, Boštjan; Kaplan, Renata; Şenilă, Marin; Pintar, Albin

    2015-01-01

    In this study, photocatalytic and catalytic wet-air oxidation (CWAO) processes were used to examine removal efficiency of bisphenol A from aqueous samples over several titanate nanotube-based catalysts. Unexpected toxicity of bisphenol A (BPA) samples treated by means of the CWAO process to some tested species was determined. In addition, the CWAO effluent was recycled five- or 10-fold in order to increase the number of interactions between the liquid phase and catalyst. Consequently, the inductively coupled plasma mass spectrometry (ICP-MS) analysis indicated higher concentrations of some toxic metals like chromium, nickel, molybdenum, silver, and zinc in the recycled samples in comparison to both the single-pass sample and the photocatalytically treated solution. The highest toxicity of five- and 10-fold recycled solutions in the CWAO process was observed in water fleas, which could be correlated to high concentrations of chromium, nickel, and silver detected in tested samples. The obtained results clearly demonstrated that aqueous samples treated by means of advanced oxidation processes should always be analyzed using (i) chemical analyses to assess removal of BPA and total organic carbon from treated aqueous samples, as well as (ii) a battery of aquatic organisms from different taxonomic groups to determine possible toxicity.

  8. An in vitro screening with emerging contaminants reveals inhibition of carboxylesterase activity in aquatic organisms.

    PubMed

    Solé, Montserrat; Sanchez-Hernandez, Juan C

    2015-12-01

    Pharmaceuticals and personal care products (PPCPs) form part of the new generation of pollutants present in many freshwater and marine ecosystems. Although environmental concentrations of these bioactive substances are low, they cause sublethal effects (e.g., enzyme inhibition) in non-target organisms. However, little is known on metabolism of PPCPs by non-mammal species. Herein, an in vitro enzyme trial was performed to explore sensitivity of carboxylesterase (CE) activity of aquatic organisms to fourteen PPCPs. The esterase activity was determined in the liver of Mediterranean freshwater fish (Barbus meridionalis and Squalius laietanus), coastal marine fish (Dicentrarchus labrax and Solea solea), middle-slope fish (Trachyrhynchus scabrus), deep-sea fish (Alepocephalus rostratus and Cataetix laticeps), and in the digestive gland of a decapod crustacean (Aristeus antennatus). Results showed that 100μM of the lipid regulators simvastatin and fenofibrate significantly inhibited (30-80% of controls) the CE activity of all target species. Among the personal care products, nonylphenol and triclosan were strong esterase inhibitors in most species (36-68% of controls). Comparison with literature data suggests that fish CE activity is as sensitive to inhibition by some PPCPs as that of mammals, although their basal activity levels are lower than in mammals. Pending further studies on the interaction between PPCPs and CE activity, we postulate that this enzyme may act as a molecular sink for certain PPCPs in a comparable way than that described for the organophosphorus pesticides.

  9. Triplet state dissolved organic matter in aquatic photochemistry: reaction mechanisms, substrate scope, and photophysical properties.

    PubMed

    McNeill, Kristopher; Canonica, Silvio

    2016-11-09

    Excited triplet states of chromophoric dissolved organic matter ((3)CDOM*) play a major role among the reactive intermediates produced upon absorption of sunlight by surface waters. After more than two decades of research on the aquatic photochemistry of (3)CDOM*, the need for improving the knowledge about the photophysical and photochemical properties of these elusive reactive species remains considerable. This critical review examines the efforts to date to characterize (3)CDOM*. Information on (3)CDOM* relies mainly on the use of probe compounds because of the difficulties associated with directly observing (3)CDOM* using transient spectroscopic methods. Singlet molecular oxygen ((1)O2), which is a product of the reaction between (3)CDOM* and dissolved oxygen, is probably the simplest indicator that can be used to estimate steady-state concentrations of (3)CDOM*. There are two major modes of reaction of (3)CDOM* with substrates, namely triplet energy transfer or oxidation (via electron transfer, proton-coupled electron transfer or related mechanisms). Organic molecules, including several environmental contaminants, that are susceptible to degradation by these two different reaction modes are reviewed. It is proposed that through the use of appropriate sets of probe compounds and model photosensitizers an improved estimation of the distribution of triplet energies and one-electron reduction potentials of (3)CDOM* can be achieved.

  10. Exploring how organic matter controls structural transformations in natural aquatic nanocolloidal dispersions.

    PubMed

    King, Stephen M; Jarvie, Helen P

    2012-07-03

    The response of the dispersion nanostructure of surface river bed sediment to the controlled removal and readdition of natural organic matter (NOM), in the absence and presence of background electrolyte, was examined using the technique of small-angle neutron scattering (SANS). Partial NOM removal induced aggregation of the mineral particles, but more extensive NOM removal restored colloidal stability. When peat humic acid (PHA) was added to a NOM-deficient sediment concentration-related structural transformations were observed: at 255 mg/L PHA aggregation of the nanocolloid was actually enhanced, but at 380 mg/L PHA disaggregation and colloidal stability were promoted. The addition of 2 mM CaCl(2) induced mild aggregation in the native sediment but not in sediments with added PHA, suggesting that the native NOM and the PHA respond differently to changes in ionic strength. A first attempt at using SANS to directly characterize the thickness and coverage of an adsorbed PHA layer in a natural nanocolloid is also presented. The results are discussed in the context of a hierarchical aquatic colloidal nanostructure, and the implications for contemporary studies of the role of dissolved organic carbon (DOC) in sustaining the transport of colloidal iron in upland catchments.

  11. Hydrologic alteration affects aquatic plant assemblages in an arid-land river

    USGS Publications Warehouse

    Vinson, Mark; Hestmark, Bennett; Barkworth, Mary E.

    2014-01-01

    We evaluated the effects of long-term flow alteration on primary-producer assemblages. In 1962, Flaming Gorge Dam was constructed on the Green River. The Yampa River has remained an unregulated hydrologically variable river that joins the Green River 100 km downstream from Flaming Gorge Dam. In the 1960s before dam construction only sparse occurrences of two macroalgae, Cladophora and Chara, and no submerged vascular plants were recorded in the Green and Yampa rivers. In 2009–2010, aquatic plants were abundant and widespread in the Green River from the dam downstream to the confluence with the Yampa River. The assemblage consisted of six vascular species, Elodea canadensis, Myriophyllum sibiricum, Nasturtium officinale,Potamogeton crispus, Potamogeton pectinatus, and Ranunculus aquatilis, the macroalgae Chara and Cladophora, and the bryophyte, Amblystegium riparium. In the Green River downstream from the Yampa River, and in the Yampa River, only sparse patches of Chara and Cladophora growing in the splash zone on boulders were collected. We attribute the observed changes in the Green River to an increase in water transparency and a reduction in suspended and bed-load sediment and high flow disturbances. The lack of hydrophyte colonization downstream from the confluence with the Yampa River has implications for understanding tributary amelioration of dam effects and for designing more natural flow-regime schedules downstream from large dams.

  12. Factors Affecting Morbidity in Solid Organ Injuries.

    PubMed

    Baygeldi, Serdar; Karakose, Oktay; Özcelik, Kazım Caglar; Pülat, Hüseyin; Damar, Sedat; Eken, Hüseyin; Zihni, İsmail; Çalta, Alpaslan Fedai; Baç, Bilsel

    2016-01-01

    Background and Aim. The aim of this study was to investigate the effects of demographic characteristics, biochemical parameters, amount of blood transfusion, and trauma scores on morbidity in patients with solid organ injury following trauma. Material and Method. One hundred nine patients with solid organ injury due to abdominal trauma during January 2005 and October 2015 were examined retrospectively in the General Surgery Department of Dicle University Medical Faculty. Patients' age, gender, trauma interval time, vital status (heart rate, arterial tension, and respiratory rate), hematocrit (HCT) value, serum area aminotransferase (ALT) and aspartate aminotransferase (AST) values, presence of free abdominal fluid in USG, trauma mechanism, extra-abdominal system injuries, injured solid organs and their number, degree of injury in abdominal CT, number of blood transfusions, duration of hospital stay, time of operation (for those undergoing operation), trauma scores (ISS, RTS, Glasgow coma scale, and TRISS), and causes of morbidity and mortality were examined. In posttraumatic follow-up period, intra-abdominal hematoma infection, emboli, catheter infection, and deep vein thrombosis were monitored as factors of morbidity. Results. One hundred nine patients were followed up and treated due to isolated solid organ injury following abdominal trauma. There were 81 males (74.3%) and 28 females (25.7%), and the mean age was 37.6 ± 18.28 (15-78) years. When examining the mechanism of abdominal trauma in patients, the following results were obtained: 58 (53.3%) traffic accidents (22 out-vehicle and 36 in-vehicle), 27 (24.7%) falling from a height, 14 (12.9%) assaults, 5 (4.5%) sharp object injuries, and 5 (4.5%) gunshot injuries. When evaluating 69 liver injuries scaled by CT the following was detected: 14 (20.3%) of grade I, 32 (46.4%) of grade II, 22 (31.8%) of grade III, and 1 (1.5%) of grade IV. In 63 spleen injuries scaled by CT the following was present: grade I in 21

  13. Experimental insights into the importance of aquatic bacterial community composition to the degradation of dissolved organic matter

    PubMed Central

    Logue, Jürg B; Stedmon, Colin A; Kellerman, Anne M; Nielsen, Nikoline J; Andersson, Anders F; Laudon, Hjalmar; Lindström, Eva S; Kritzberg, Emma S

    2016-01-01

    Bacteria play a central role in the cycling of carbon, yet our understanding of the relationship between the taxonomic composition and the degradation of dissolved organic matter (DOM) is still poor. In this experimental study, we were able to demonstrate a direct link between community composition and ecosystem functioning in that differently structured aquatic bacterial communities differed in their degradation of terrestrially derived DOM. Although the same amount of carbon was processed, both the temporal pattern of degradation and the compounds degraded differed among communities. We, moreover, uncovered that low-molecular-weight carbon was available to all communities for utilisation, whereas the ability to degrade carbon of greater molecular weight was a trait less widely distributed. Finally, whereas the degradation of either low- or high-molecular-weight carbon was not restricted to a single phylogenetic clade, our results illustrate that bacterial taxa of similar phylogenetic classification differed substantially in their association with the degradation of DOM compounds. Applying techniques that capture the diversity and complexity of both bacterial communities and DOM, our study provides new insight into how the structure of bacterial communities may affect processes of biogeochemical significance. PMID:26296065

  14. Organic contaminants in Great Lakes tributaries: Prevalence and potential aquatic toxicity.

    PubMed

    Baldwin, Austin K; Corsi, Steven R; De Cicco, Laura A; Lenaker, Peter L; Lutz, Michelle A; Sullivan, Daniel J; Richards, Kevin D

    2016-06-01

    Organic compounds used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewer overflows, among other sources. Concentrations of these organic waste compounds (OWCs) in some Great Lakes tributaries indicate a high potential for adverse impacts on aquatic organisms. During 2010-13, 709 water samples were collected at 57 tributaries, together representing approximately 41% of the total inflow to the lakes. Samples were collected during runoff and low-flow conditions and analyzed for 69 OWCs, including herbicides, insecticides, polycyclic aromatic hydrocarbons, plasticizers, antioxidants, detergent metabolites, fire retardants, non-prescription human drugs, flavors/fragrances, and dyes. Urban-related land cover characteristics were the most important explanatory variables of concentrations of many OWCs. Compared to samples from nonurban watersheds (<15% urban land cover) samples from urban watersheds (>15% urban land cover) had nearly four times the number of detected compounds and four times the total sample concentration, on average. Concentration differences between runoff and low-flow conditions were not observed, but seasonal differences were observed in atrazine, metolachlor, DEET, and HHCB concentrations. Water quality benchmarks for individual OWCs were exceeded at 20 sites, and at 7 sites benchmarks were exceeded by a factor of 10 or more. The compounds with the most frequent water quality benchmark exceedances were the PAHs benzo[a]pyrene, pyrene, fluoranthene, and anthracene, the detergent metabolite 4-nonylphenol, and the herbicide atrazine. Computed estradiol equivalency quotients (EEQs) using only nonsteroidal endocrine-active compounds indicated medium to high risk of estrogenic effects (intersex or vitellogenin induction) at 10 sites. EEQs at 3 sites were comparable to values reported in effluent. This multifaceted study is

  15. Organic contaminants in Great Lakes tributaries: Prevalence and potential aquatic toxicity

    USGS Publications Warehouse

    Baldwin, Austin K.; Corsi, Steven R.; De Cicco, Laura A.; Lenaker, Peter L.; Lutz, Michelle A; Sullivan, Daniel J.; Richards, Kevin D.

    2016-01-01

    Organic compounds used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewer overflows, among other sources. Concentrations of these organic waste compounds (OWCs) in some Great Lakes tributaries indicate a high potential for adverse impacts on aquatic organisms. During 2010–13, 709 water samples were collected at 57 tributaries, together representing approximately 41% of the total inflow to the lakes. Samples were collected during runoff and low-flow conditions and analyzed for 69 OWCs, including herbicides, insecticides, polycyclic aromatic hydrocarbons, plasticizers, antioxidants, detergent metabolites, fire retardants, non-prescription human drugs, flavors/fragrances, and dyes. Urban-related land cover characteristics were the most important explanatory variables of concentrations of many OWCs. Compared to samples from nonurban watersheds (< 15% urban land cover) samples from urban watersheds (> 15% urban land cover) had nearly four times the number of detected compounds and four times the total sample concentration, on average. Concentration differences between runoff and low-flow conditions were not observed, but seasonal differences were observed in atrazine, metolachlor, DEET, and HHCB concentrations. Water quality benchmarks for individual OWCs were exceeded at 20 sites, and at 7 sites benchmarks were exceeded by a factor of 10 or more. The compounds with the most frequent water quality benchmark exceedances were the PAHs benzo[a]pyrene, pyrene, fluoranthene, and anthracene, the detergent metabolite 4-nonylphenol, and the herbicide atrazine. Computed estradiol equivalency quotients (EEQs) using only nonsteroidal endocrine-active compounds indicated medium to high risk of estrogenic effects (intersex or vitellogenin induction) at 10 sites. EEQs at 3 sites were comparable to values reported in effluent. This multifaceted study

  16. Defining an exposure-response relationship for suspended kaolin clay particulates and aquatic organisms: work toward defining a water quality guideline for suspended solids.

    PubMed

    Gordon, Andrew K; Palmer, Carolyn G

    2015-04-01

    Water quality guidelines for suspended solids generally rely on the percentage departure from reference condition, an approach that has been criticized. Attempts to develop a biological effects-base guideline have, however, been confounded by low data availability. Furthermore, the high biological response variability to suspended solids exposure suggests that organisms are responding not only to exposure concentration and duration but also to other mechanisms of effect associated with suspended particles (e.g., size, shape, and geochemical composition). An alternative option is to develop more situation and site specific guidelines by generating biological effects data to suspended particles of a particular geochemistry and restricted size range. With this in mind, aquatic organism responses to kaolin clay particle exposure were collated from the literature and incorporated into 2 exposure-response relationship approaches. The species sensitivity distribution approach produced a hazardous concentration affecting 5% of species estimate of 58 mg/L for mortality responses, and 36 mg/L for sublethal data. The severity-of-ill-effect approach produced similar estimates for lethal and sublethal data. These results suggest that aquatic organisms are slightly more tolerant of kaolin clay particles than particles from barite or bentonite clays, based on results from previous studies on these clay types. This type of information can enable better estimates of the risk faced by aquatic organisms exposed to suspended solids. For example, when the sediments of a particular water body are dominated by a particular type of clay particle, then the most appropriate exposure-response relationship can be applied.

  17. A comparison of water solubility enhancements of organic solutes by aquatic humic materials and commercial humic acids

    USGS Publications Warehouse

    Chlou, C.T.; Kile, D.E.; Brinton, T.I.; Malcolm, R.L.; Leenheer, J.A.; MacCarthy, P.

    1987-01-01

    Water solubility enhancements of 1,1-bis(p-chloro-phenyl)-2,2,2-trichloroethane (p,p???-DDT), 2,4,5,2???,5???-pentachlorobiphenyl (2,4,5,2???,5???-PCB), and 2,4,4???-tri-chlorobiphenyl (2,4,4???-PCB) by dissolved organic matter have been studied with the following samples: (1) acidic water samples from the Suwannee River, Georgia, and the Sopchoppy River, Florida; (2) a humic extract of a nearly neutral pH water from the Calcasieu River, Louisiana; (3) commercial humic acids from the Aldrich Chemical Co. and Fluka-Tridom Chemical Corp. The calculated partition coefficients on a dissolved organic carbon basis (Kdoc) for organic solutes with water samples and aquatic humic extracts from this and earlier studies indicate that the enhancement effect varies with the molecular composition of the aquatic humic materials. The Kdoc values with water and aquatic humic samples are, however, far less than the observed Kdoc values obtained with the two commercial samples, by factors of about 4-20. In view of this finding, one should be cautious in interpreting the effects of the dissolved organic matter on solubility enhancement of organic solutes on the basis of the use of commercial humic acids.

  18. Toxicity of organic pollutants to seven aquatic organisms: effect of polarity and ionization.

    PubMed

    Qin, W C; Su, L M; Zhang, X J; Qin, H W; Wen, Y; Guo, Z; Sun, F T; Sheng, L X; Zhao, Y H; Abraham, M H

    2010-07-01

    The toxicity of organic chemicals to Vibrio fischeri, river bacteria, algae, Daphnia magna and fishes were analysed. The results showed that the toxicity of chemicals to narcotics was dependent on hydrophobicity. A single model for both polar and non-polar narcotics was developed by inclusion of a polarity descriptor as well as the hydrophobic parameter. The highly hydrophobic polar narcotics could be treated as non-polar narcotics because their polar functional group(s) make(s) a relatively small contribution to polarity as compared with their hydrophobicity. In order to investigate the toxic mechanism of action for reactive compounds, the response-surface approach was used to develop models derived from easily calculated descriptors. The stepwise analysis selected the octanol/water partition coefficient and a polarity descriptor to parameterize bio-uptake and reactivity, respectively, for seven species. Benzoic acids can be easily absorbed into the unicellular bacteria, but this is not the case for multicellular D. magna and fish. Their toxicity to V. fischeri is much higher than that to D. magna and carp. Regression analysis was performed based on the model that we developed for ionizable compounds. Good correlations were observed by introducing the correction factor for ionizable compounds. The toxic mechanisms are discussed.

  19. INFLUENCE OF DISSOLVED ORGANIC MATTER ON AGROCHEMICAL PHOTOREACTIONS IN AQUATIC ENVIRONMENTS

    EPA Science Inventory

    Pioneering studies by Don Crosby and co-workers demonstrated that the sunlight-induced dissipation of agrochemicals in water often is strongly affected by natural constituents in the water such as nitrate and dissolved organic matter. In this presentation, the focus is on the rol...

  20. An overview of UV-absorbing compounds (organic UV filters) in aquatic biota.

    PubMed

    Gago-Ferrero, Pablo; Díaz-Cruz, M Silvia; Barceló, Damià

    2012-11-01

    The purpose of this article is to summarize biological monitoring information on UV-absorbing compounds, commonly referred as organic UV filters or sunscreen agents, in aquatic ecosystems. To date a limited range of species (macroinvertebrates, fish, and birds), habitats (lakes, rivers, and sea), and compounds (benzophenones and camphors) have been investigated. As a consequence there is not enough data enabling reliable understanding of the global distribution and effect of UV filters on ecosystems. Both liquid chromatography and gas chromatography coupled with mass spectrometry-based methods have been developed and applied to the trace analysis of these pollutants in biota, enabling the required selectivity and sensitivity. As expected, the most lipophilic compounds occur most frequently with concentrations up to 7112 ng g(-1) lipids in mussels and 3100 ng g(-1) lipids (homosalate) in fish. High concentrations have also been reported for 4-methylbenzilidenecamphor (up to 1800 ng g(-1) lipids) and octocrylene (2400 ng g(-1) lipids). Many fewer studies have evaluated the potential bioaccumulation and biomagnification of these compounds in both fresh and marine water and terrestrial food webs. Estimated biomagnification factors suggest biomagnification in predator-prey pairs, for example bird-fish and fish-invertebrates. Ecotoxicological data and preliminary environmental assessment of the risk of UV filters are also included and discussed.

  1. Acute toxicity assessment of Osthol content in bio-pesticides using two aquatic organisms

    PubMed Central

    Yim, Eun-Chae; Kim, Hyeon Joe; Kim, Seong-Jun

    2014-01-01

    Objectives This study focused on the assessment of acute toxicity caused by Osthol, a major component of environment-friendly biological pesticides, by using two aquatic organisms. Methods The assessment of acute toxicity caused by Osthol was conducted in Daphnia magna and by examining the morphological abnormalities in Danio rerio embryos. Results The median effective concentration value of Osthol in D. magna 48 hours after inoculation was 19.3 μM. The median lethal concentration of D. rerio embryo at 96 hours was 30.6 μM. No observed effect concentration and predicted no effect concentration values of Osthol in D. magna and D. rerio were calculated as 5.4 and 0.19 μM, respectively. There was an increase in the morphological abnormalities in D. rerio embryo due to Osthol over time. Coagulation, delayed hatching, yolk sac edema, pericardial edema, and pigmentation were observed in embryos at 24–48 hours. Symptoms of scoliosis and head edema occurred after 72 hours. In addition, bent tails, ocular defects, and symptoms of collapse were observed in fertilized embryo tissue within 96 hours. Ocular defects and pigmentation were the additional symptoms observed in this study. Conclusions Because Osthol showed considerable toxicity levels continuous toxicity evaluation in agro-ecosystems is necessary when bio-pesticides containing Osthol are used. PMID:25518842

  2. Inability to detect free cylindrospermopsin in spiked aquatic organism extracts plausibly suggests protein binding.

    PubMed

    Esterhuizen-Londt, Maranda; Pflugmacher, Stephan

    2016-11-01

    Even though the frequency and prevalence of cylindrospermopsin producing cyanobacteria are increasing, several publications have reported the absence of free cylindrospermopsin bioaccumulation in aquatic food chains. Cylindrospermopsin modification by protein binding has been suggested, however, only one publication has investigated this with eukaryotic reticulocyte lysate and concluded that cylindrospermopsin binds non-covalently to soluble proteins larger than 100 kDa associated with eukaryotic translation. With this as the extent of knowledge regarding cylindrospermopsin binding, the present study aimed to determine whether cylindrospermopsin binding also occurred with other proteins. In the present study, proteins from various organisms were extracted, incubated with cylindrospermopsin, and the amount of free cylindrospermopsin was determined by liquid chromatography tandem mass spectroscopy. Additionally, cylindrospermopsin binding to various ammonium sulfate precipitation fractions of Egeria densa protein, as well as with selected amino acids was investigated. We find that the percentage of free cylindrospermopsin varied with exposure to various animal and plant proteins as well as with various fractions of proteins but found no binding with single amino acids.

  3. Environmental DNA sampling protocol - filtering water to capture DNA from aquatic organisms

    USGS Publications Warehouse

    Laramie, Matthew B.; Pilliod, David S.; Goldberg, Caren S.; Strickler, Katherine M.

    2015-09-29

    Environmental DNA (eDNA) analysis is an effective method of determining the presence of aquatic organisms such as fish, amphibians, and other taxa. This publication is meant to guide researchers and managers in the collection, concentration, and preservation of eDNA samples from lentic and lotic systems. A sampling workflow diagram and three sampling protocols are included as well as a list of suggested supplies. Protocols include filter and pump assembly using: (1) a hand-driven vacuum pump, ideal for sample collection in remote sampling locations where no electricity is available and when equipment weight is a primary concern; (2) a peristaltic pump powered by a rechargeable battery-operated driver/drill, suitable for remote sampling locations when weight consideration is less of a concern; (3) a 120-volt alternating current (AC) powered peristaltic pump suitable for any location where 120-volt AC power is accessible, or for roadside sampling locations. Images and detailed descriptions are provided for each step in the sampling and preservation process.

  4. Measurement of dissolved organic matter fluorescense in aquatic environments: An interlaboratory comparison

    USGS Publications Warehouse

    Murphy, Kathleen R.; Butler, Kenna D.; Spencer, Robert G. M.; Stedmon, Colin A.; Boehme, Jennifer R.; Aiken, George R.

    2010-01-01

    The fluorescent properties of dissolved organic matter (DOM) are often studied in order to infer DOM characteristics in aquatic environments, including source, quantity, composition, and behavior. While a potentially powerful technique, a single widely implemented standard method for correcting and presenting fluorescence measurements is lacking, leading to difficulties when comparing data collected by different research groups. This paper reports on a large-scale interlaboratory comparison in which natural samples and well-characterized fluorophores were analyzed in 20 laboratories in the U.S., Europe, and Australia. Shortcomings were evident in several areas, including data quality-assurance, the accuracy of spectral correction factors used to correct EEMs, and the treatment of optically dense samples. Data corrected by participants according to individual laboratory procedures were more variable than when corrected under a standard protocol. Wavelength dependency in measurement precision and accuracy were observed within and between instruments, even in corrected data. In an effort to reduce future occurrences of similar problems, algorithms for correcting and calibrating EEMs are described in detail, and MATLAB scripts for implementing the study's protocol are provided. Combined with the recent expansion of spectral fluorescence standards, this approach will serve to increase the intercomparability of DOM fluorescence studies.

  5. Correlates of Instrumental and Affective Attachment to Organizations.

    ERIC Educational Resources Information Center

    Angle, Harold L.

    It has been suggested that different forms of organizational commitment have different outcomes as well as different antecedents. To test the hypothesis that instrumental attachment to an organization is associated with members' investments in the organization, and that affective attachment to an organization is influenced primarily by the way the…

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

    PubMed

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

    2015-12-01

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

  7. Toxicity of select beta adrenergic receptor-blocking pharmaceuticals (B-blockers) on aquatic organisms.

    PubMed

    Huggett, D B; Brooks, B W; Peterson, B; Foran, C M; Schlenk, D

    2002-08-01

    One class of pharmaceutical compounds identified in U.S. and European waters are the B-adrenergic receptor blocking compounds (B-blockers). However, little information is available on the potential aquatic toxicity of these compounds. Therefore, Hyalella azteca, Daphnia magna, Ceriodaphnia dubia, and Oryias latipes (Japanese medaka) were exposed to metoprolol, nadolol, and propranolol to determine potential toxicity. Average 48-h LC(50) for propranolol to H. azteca was 29.8 mg/L. The no-observed-effects concentration (NOEC) and lowest-observed-effects concentration (LOEC) for propranolol affecting reproduction of H. azteca were 0.001 and 0.1 mg/L, respectively. The average propranolol and metoprolol 48-h LC(50)s for D. magna were 1.6 and 63.9 mg/L, respectively. C. dubia 48-h LC(50)s were 0.85 and 8.8 mg/L for propranolol and metoprolol, respectively. The NOEC and LOEC of propranolol affecting reproduction in C. dubia were 0.125 and 0.25 mg/L, respectively. In O. latipes, the propranolol 48-h LC(50) was 24.3 mg/L. Medaka growth was decreased at 0.5 mg/L propranolol. A 2-week medaka reproductive study indicated significant changes in plasma steroid levels; however, no changes in the average number of eggs produced or number of viable eggs which hatched was observed. In a 4-week follow-up propranolol exposure, the total number of eggs produced by medaka and the number of viable eggs that hatched were decreased at concentrations as low as 0.5 microg/L. Based on this study and the expected aqueous environmental exposure levels, adverse effects of propranolol to invertebrate populations is unlikely; however, further reproductive studies are need to elucidate the risk to teleosts.

  8. Particulate Organic Matter Distribution along the Lower Amazon River: Addressing Aquatic Ecology Concepts Using Fatty Acids

    PubMed Central

    Mortillaro, Jean-Michel; Rigal, François; Rybarczyk, Hervé; Bernardes, Marcelo; Abril, Gwenaël; Meziane, Tarik

    2012-01-01

    One of the greatest challenges in understanding the Amazon basin functioning is to ascertain the role played by floodplains in the organic matter (OM) cycle, crucial for a large spectrum of ecological mechanisms. Fatty acids (FAs) were combined with environmental descriptors and analyzed through multivariate and spatial tools (asymmetric eigenvector maps, AEM and principal coordinates of neighbor matrices, PCNM). This challenge allowed investigating the distribution of suspended particulate organic matter (SPOM), in order to trace its seasonal origin and quality, along a 800 km section of the Amazon river-floodplain system. Statistical analysis confirmed that large amounts of saturated FAs (15:0, 18:0, 24:0, 25:0 and 26:0), an indication of refractory OM, were concomitantly recorded with high pCO2 in rivers, during the high water season (HW). Contrastingly, FAs marker which may be attributed in this ecosystem to aquatic plants (18:2ω6 and 18:3ω3) and cyanobacteria (16:1ω7), were correlated with higher O2, chlorophyll a and pheopigments in floodplains, due to a high primary production during low waters (LW). Decreasing concentrations of unsaturated FAs, that characterize labile OM, were recorded during HW, from upstream to downstream. Furthermore, using PCNM and AEM spatial methods, FAs compositions of SPOM displayed an upstream-downstream gradient during HW, which was attributed to OM retention and the extent of flooded forest in floodplains. Discrimination of OM quality between the Amazon River and floodplains corroborate higher autotrophic production in the latter and transfer of OM to rivers at LW season. Together, these gradients demonstrate the validity of FAs as predictors of spatial and temporal changes in OM quality. These spatial and temporal trends are explained by 1) downstream change in landscape morphology as predicted by the River Continuum Concept; 2) enhanced primary production during LW when the water level decreased and its residence time

  9. Particulate organic matter distribution along the lower Amazon River: addressing aquatic ecology concepts using fatty acids.

    PubMed

    Mortillaro, Jean-Michel; Rigal, François; Rybarczyk, Hervé; Bernardes, Marcelo; Abril, Gwenaël; Meziane, Tarik

    2012-01-01

    One of the greatest challenges in understanding the Amazon basin functioning is to ascertain the role played by floodplains in the organic matter (OM) cycle, crucial for a large spectrum of ecological mechanisms. Fatty acids (FAs) were combined with environmental descriptors and analyzed through multivariate and spatial tools (asymmetric eigenvector maps, AEM and principal coordinates of neighbor matrices, PCNM). This challenge allowed investigating the distribution of suspended particulate organic matter (SPOM), in order to trace its seasonal origin and quality, along a 800 km section of the Amazon river-floodplain system. Statistical analysis confirmed that large amounts of saturated FAs (15:0, 18:0, 24:0, 25:0 and 26:0), an indication of refractory OM, were concomitantly recorded with high pCO(2) in rivers, during the high water season (HW). Contrastingly, FAs marker which may be attributed in this ecosystem to aquatic plants (18:2ω6 and 18:3ω3) and cyanobacteria (16:1ω7), were correlated with higher O(2), chlorophyll a and pheopigments in floodplains, due to a high primary production during low waters (LW). Decreasing concentrations of unsaturated FAs, that characterize labile OM, were recorded during HW, from upstream to downstream. Furthermore, using PCNM and AEM spatial methods, FAs compositions of SPOM displayed an upstream-downstream gradient during HW, which was attributed to OM retention and the extent of flooded forest in floodplains. Discrimination of OM quality between the Amazon River and floodplains corroborate higher autotrophic production in the latter and transfer of OM to rivers at LW season. Together, these gradients demonstrate the validity of FAs as predictors of spatial and temporal changes in OM quality. These spatial and temporal trends are explained by 1) downstream change in landscape morphology as predicted by the River Continuum Concept; 2) enhanced primary production during LW when the water level decreased and its residence time

  10. Fish Karyome version 2.1: a chromosome database of fishes and other aquatic organisms

    PubMed Central

    Nagpure, Naresh Sahebrao; Pathak, Ajey Kumar; Pati, Rameshwar; Rashid, Iliyas; Sharma, Jyoti; Singh, Shri Prakash; Singh, Mahender; Sarkar, Uttam Kumar; Kushwaha, Basdeo; Kumar, Ravindra; Murali, S.

    2016-01-01

    A voluminous information is available on karyological studies of fishes; however, limited efforts were made for compilation and curation of the available karyological data in a digital form. ‘Fish Karyome’ database was the preliminary attempt to compile and digitize the available karyological information on finfishes belonging to the Indian subcontinent. But the database had limitations since it covered data only on Indian finfishes with limited search options. Perceiving the feedbacks from the users and its utility in fish cytogenetic studies, the Fish Karyome database was upgraded by applying Linux, Apache, MySQL and PHP (pre hypertext processor) (LAMP) technologies. In the present version, the scope of the system was increased by compiling and curating the available chromosomal information over the globe on fishes and other aquatic organisms, such as echinoderms, molluscs and arthropods, especially of aquaculture importance. Thus, Fish Karyome version 2.1 presently covers 866 chromosomal records for 726 species supported with 253 published articles and the information is being updated regularly. The database provides information on chromosome number and morphology, sex chromosomes, chromosome banding, molecular cytogenetic markers, etc. supported by fish and karyotype images through interactive tools. It also enables the users to browse and view chromosomal information based on habitat, family, conservation status and chromosome number. The system also displays chromosome number in model organisms, protocol for chromosome preparation and allied techniques and glossary of cytogenetic terms. A data submission facility has also been provided through data submission panel. The database can serve as a unique and useful resource for cytogenetic characterization, sex determination, chromosomal mapping, cytotaxonomy, karyo-evolution and systematics of fishes. Database URL: http://mail.nbfgr.res.in/Fish_Karyome PMID:26980518

  11. Ultraviolet irradiation effects incorporation of nitrate and nitrite nitrogen into aquatic natural organic matter

    USGS Publications Warehouse

    Thorn, Kevin A.; Cox, Larry G.

    2012-01-01

    One of the concerns regarding the safety and efficacy of ultraviolet radiation for treatment of drinking water and wastewater is the fate of nitrate, particularly its photolysis to nitrite. In this study, 15N NMR was used to establish for the first time that UV irradiation effects the incorporation of nitrate and nitrite nitrogen into aquatic natural organic matter (NOM). Irradiation of 15N-labeled nitrate in aqueous solution with an unfiltered medium pressure mercury lamp resulted in the incorporation of nitrogen into Suwannee River NOM (SRNOM) via nitrosation and other reactions over a range of pH from approximately 3.2 to 8.0, both in the presence and absence of bicarbonate, confirming photonitrosation of the NOM. The major forms of the incorporated label include nitrosophenol, oxime/nitro, pyridine, nitrile, and amide nitrogens. Natural organic matter also catalyzed the reduction of nitrate to ammonia on irradiation. The nitrosophenol and oxime/nitro nitrogens were found to be susceptible to photodegradation on further irradiation when nitrate was removed from the system. At pH 7.5, unfiltered irradiation resulted in the incorporation of 15N-labeled nitrite into SRNOM in the form of amide, nitrile, and pyridine nitrogen. In the presence of bicarbonate at pH 7.4, Pyrex filtered (cutoff below 290–300 nm) irradiation also effected incorporation of nitrite into SRNOM as amide nitrogen. We speculate that nitrosation of NOM from the UV irradiation of nitrate also leads to production of nitrogen gas and nitrous oxide, a process that may be termed photo-chemodenitrification. Irradiation of SRNOM alone resulted in transformation or loss of naturally abundant heterocyclic nitrogens.

  12. Fish Karyome version 2.1: a chromosome database of fishes and other aquatic organisms.

    PubMed

    Nagpure, Naresh Sahebrao; Pathak, Ajey Kumar; Pati, Rameshwar; Rashid, Iliyas; Sharma, Jyoti; Singh, Shri Prakash; Singh, Mahender; Sarkar, Uttam Kumar; Kushwaha, Basdeo; Kumar, Ravindra; Murali, S

    2016-01-01

    A voluminous information is available on karyological studies of fishes; however, limited efforts were made for compilation and curation of the available karyological data in a digital form. 'Fish Karyome' database was the preliminary attempt to compile and digitize the available karyological information on finfishes belonging to the Indian subcontinent. But the database had limitations since it covered data only on Indian finfishes with limited search options. Perceiving the feedbacks from the users and its utility in fish cytogenetic studies, the Fish Karyome database was upgraded by applying Linux, Apache, MySQL and PHP (pre hypertext processor) (LAMP) technologies. In the present version, the scope of the system was increased by compiling and curating the available chromosomal information over the globe on fishes and other aquatic organisms, such as echinoderms, molluscs and arthropods, especially of aquaculture importance. Thus, Fish Karyome version 2.1 presently covers 866 chromosomal records for 726 species supported with 253 published articles and the information is being updated regularly. The database provides information on chromosome number and morphology, sex chromosomes, chromosome banding, molecular cytogenetic markers, etc. supported by fish and karyotype images through interactive tools. It also enables the users to browse and view chromosomal information based on habitat, family, conservation status and chromosome number. The system also displays chromosome number in model organisms, protocol for chromosome preparation and allied techniques and glossary of cytogenetic terms. A data submission facility has also been provided through data submission panel. The database can serve as a unique and useful resource for cytogenetic characterization, sex determination, chromosomal mapping, cytotaxonomy, karyo-evolution and systematics of fishes. Database URL: http://mail.nbfgr.res.in/Fish_Karyome.

  13. The effects of humic acid on the uptake and depuration of fullerene aqueous suspensions in two aquatic organisms.

    PubMed

    Chen, Qiqing; Yin, Daqiang; Li, Jing; Hu, Xialin

    2014-05-01

    The authors investigated the uptake and depuration of fullerene aqueous suspensions (nC(60)) in 2 aquatic organisms: Daphnia magna and zebrafish. The effects of humic acid were examined to elucidate its possible mechanisms in the aquatic environment. The uptake was concentration-dependent in both organisms, and the maximum uptake concentration of nC(60) in Daphnia (2268 ± 158 mg/kg) was approximately 1 order of magnitude higher than that in zebrafish (222 ± 30 mg/kg) because of the larger gut volume ratio to the mass of Daphnia or its high uptake efficiency. Humic acid reduced the uptake of nC(60) in Daphnia and zebrafish as a result of the size effect and the polarity alternation of nC(60). The depuration patterns were rapid for Daphnia and slow for zebrafish, and the differences were most likely the result of different water exchange frequencies between organisms. The remaining nC(60) percentages were approximately 20% for Daphnia and 30% for zebrafish after 48-h depuration, suggesting that a large nC(60) burden still existed for both aquatic organisms and that there is a need for further studies on the potential for trophic transfer.

  14. Assessment of biomarkers for contaminants of emerging concern on aquatic organisms downstream of a municipal wastewater discharge.

    PubMed

    Jasinska, Edyta J; Goss, Greg G; Gillis, Patricia L; Van Der Kraak, Glen J; Matsumoto, Jacqueline; de Souza Machado, Anderson A; Giacomin, Marina; Moon, Thomas W; Massarsky, Andrey; Gagné, Francois; Servos, Mark R; Wilson, Joanna; Sultana, Tamanna; Metcalfe, Chris D

    2015-10-15

    Contaminants of emerging concern (CECs), including pharmaceuticals, personal care products and estrogens, are detected in wastewater treatment plant (WWTP) discharges. However, analytical monitoring of wastewater and surface water does not indicate whether CECs are affecting the organisms downstream. In this study, fathead minnows (Pimephales promelas) and freshwater mussels Pyganodon grandis Say, 1829 (synonym: Anodonta grandis Say, 1829) were caged for 4 weeks in the North Saskatchewan River, upstream and downstream of the discharge from the WWTP that serves the Edmonton, AB, Canada. Passive samplers deployed indicated that concentrations of pharmaceuticals, personal care products, an estrogen (estrone) and an androgen (androstenedione) were elevated at sites downstream of the WWTP discharge. Several biomarkers of exposure were significantly altered in the tissues of caged fathead minnows and freshwater mussels relative to the upstream reference sites. Biomarkers altered in fish included induction of CYP3A metabolism, an increase in vitellogenin (Vtg) gene expression in male minnows, elevated ratios of oxidized to total glutathione (i.e. GSSG/TGSH), and an increase in the activity of antioxidant enzymes (i.e. glutathione reductase, glutathione-S-transferase). In mussels, there were no significant changes in biomarkers of oxidative stress and the levels of Vtg-like proteins were reduced, not elevated, indicating a generalized stress response. Immune function was altered in mussels, as indicated by elevated lysosomal activity per hemocyte in P. grandis caged closest to the wastewater discharge. This immune response may be due to exposure to bacterial pathogens in the wastewater. Multivariate analysis indicated a response to the CECs Carbamazepine (CBZ) and Trimethoprim (TPM). Overall, these data indicate that there is a 1 km zone of impact for aquatic organisms downstream of WWTP discharge. However, multiple stressors in municipal wastewater make measurement and

  15. Developing biohopanoid molecular proxies for bacterially derived soil organic matter and its fate in aquatic systems

    NASA Astrophysics Data System (ADS)

    Talbot, H. M.; Cooke, M. P.; Zhu, C.; Handley, L.; Van Dongen, B.; Doğrul Selver, A.; Kim, J.; Pancost, R. D.; Pereira, R.; Graham, D.; Wagner, T.

    2011-12-01

    Microbially-mediated processes at the Earth's surface and in the subsurface are fundamental controls on the global carbon and climate cycle. Bacteria and other microorganisms produce a variety of lipid biomarkers which are important for studying their activity in modern and Recent environments; however, many of these molecules are not well preserved in the sedimentary record. A developing approach to tackle bacterial biomarkers in sediments is to apply bacteriohopanepolyols (BHPs), membrane lipids biosynthesised by many, but not all bacteria. Recently identified in sediments up to 55 Ma, these compounds, consist of a stable pentacyclic hydrocarbon skeleton with an extended, highly functionalised side chain containing at least 4 functional groups. BHPs are significant components in soils and sediments and although some BHPs have a diverse range of biological source organisms, others have more restricted origins. Recently several BHPs have been proposed as novel markers for specific biogeochemical processes including aerobic methane oxidation and nitrogen-fixation. Here we will focus on the persistent need to understand carbon dynamics and reactions involving organic matter at the land-ocean interface which has lead to a proposed new BHP based approach. We have identified a group of compounds related to adenosylhopane which are highly abundant components in soils but generally scarce or absent in lacustrine sediments and open marine systems. We propose that the relative contribution of this group of compounds to the sedimentary BHP pool may be a useful proxy for terrestrial organic matter input. Development is still ongoing; however, as a foundation to this application we have surveyed the BHP composition of over 600 soil samples from around the world including new samples from the tropics and polar regions and will here present a synthesis of this data, comparing terrestrial BHP fingerprints to those from a range of aquatic sediments located within different climate

  16. A systems-based approach to predict biological responses of aquatic organisms to complex environmental mixtures

    EPA Science Inventory

    Contaminants of emerging concern (CECs) such as new-generation pesticides, pharmaceuticals, household and personal care products, steroid hormones, and flame retardants enter the aquatic environment through multiple sources such as wastewater treatment plants and agricultural ope...

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

    SciTech Connect

    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.

  18. Long-Term Effects of Dredging Operations Program: Assessing Bioaccumulation in Aquatic Organisms Exposed to Contaminated Sediments

    DTIC Science & Technology

    1991-07-01

    Bioconcentration of Hydrophobic Chemicals by Fish ," Ecotoxicology and Environmental Safety. Vol 16, pp 242-257. Connolly, J. P., and Pedersen, C. J...Ocean Disposal of Wastes," Chapter 12 in Fate and Effects of Sediment-Bound Chemicals in Aauatic Systems , K. C. Dickson, A. W. Maki, and W. A. Brungs...AD-A239 551 LONG-TERM EFFECTS OF DREDGING{Tf I IIIID . OPERATIONS PROGRAM MISCELLANEOUS PAPER D-91-2 ASSESSING BIOACCUMULATION IN AQUATIC ORGANISMS

  19. Complex inter-Kingdom interactions: carnivorous plants affect growth of an aquatic vertebrate.

    PubMed

    Davenport, Jon M; Riley, Alex W

    2017-05-01

    Coexistence of organisms in nature is more likely when phenotypic similarities of individuals are reduced. Despite the lack of similarity, distantly related taxa still compete intensely for shared resources. No larger difference between organisms that share a common prey could exist than between carnivorous plants and animals. However, few studies have considered inter-Kingdom competition among carnivorous plants and animals. In order to evaluate interactions between a carnivorous plant (greater bladderwort, Utricularia vulgaris) and a vertebrate (bluegill, Lepomis macrochirus) on a shared prey (zooplankton), we conducted a mesocosm experiment. We deployed two levels of bladderwort presence (functional and crushed) and measured bluegill responses (survival and growth). Zooplankton abundance was reduced the greatest in bluegill and functional bladderwort treatments. Bluegill survival did not differ among treatments, but growth was greatest with crushed bladderwort. Thus, bluegill growth was facilitated by reducing interference competition in the presence of crushed bladderwort. The facilitating effect was dampened, however, when functional bladderwort removed a shared prey. To our knowledge, this is one of the first studies to experimentally demonstrate interactions between a carnivorous plant and a fish. Our data suggest that carnivorous plants may actively promote or reduce animal co-occurrence from some ecosystems via facilitation or competition.

  20. Uptake and toxic effects of surface modified nanomaterials in freshwater aquatic organisms

    NASA Astrophysics Data System (ADS)

    Seda, Brandon Casey

    Nanomaterials are a class of materials with unique properties due to their size, and the association of these properties with the toxicity of nanomaterials is poorly understood. The present study assessed the toxic effects of stable aqueous colloidal suspensions of three distinctly different classes of nanomaterials in aquatic organisms. The fullerene, C70, was stabilized through non-covalent surface modification with gallic acid. Toxicity of C70-gallic acid was confirmed to exhibit similar toxic effects as C60-fullerene, including changes in antioxidative processes in Daphnia magna. Daphnia magna fecundity was significantly reduced in 21d bioassays at C70-gallic concentrations below quantifiable limits (0.03 mg/L C70). Antioxidant enzyme activities of glutathione peroxidase and superoxide dismutase as well as lipid peroxidation suggested that exposed organisms experienced oxidative stress. Carbon dots are a class of nanomaterials proposed for use as nontoxic alternatives to semiconductor quantum dots for photoluminescent applications, because of the difference in toxicity of their core components: carbon as opposed to heavy metals. In vivo analysis of treated organisms by confocal fluorescence microscopy revealed carbon dots were absorbed and systemically distributed regardless of particle size. The present study did not find any evidence of acute toxicity at concentrations up to 10mg/L carbon dots. These concentrations also failed to produce negative effects in Ceriodaphnia dubia bioassays to predict chronic toxicity. Carbon dots also failed to elicit developmental toxic effects in zebrafish. The toxic effects of semiconductor quantum dots have been partially attributed to the release of heavy metals with their degradation, particularly cadmium. Laser ablation inductively coupled mass spectrometry was used to compare the uptake of cadmium, selenium and zinc in Daphnia magna treated to CdSe/ZnS quantum dots or CdCl2. These quantum dots were observed to accumulate

  1. Uptake and toxicity of methylmethacrylate-based nanoplastic particles in aquatic organisms.

    PubMed

    Booth, Andy M; Hansen, Bjørn Henrik; Frenzel, Max; Johnsen, Heidi; Altin, Dag

    2016-07-01

    The uptake and toxicity of 2 poly(methylmethacrylate)-based plastic nanoparticles (PNPs) with different surface chemistries (medium and hydrophobic) were assessed using aquatic organisms selected for their relevance based on the environmental behavior of the PNPs. Pure poly(methylmethacrylate) (medium; PMMA PNPs) and poly(methylmethacrylate-co-stearylmethacrylate) copolymer (hydrophobic; PMMA-PSMA PNPs) of 86 nm to 125 nm were synthesized using a miniemulsion polymerization method. Fluorescent analogs of each PNP were also synthesized using monomer 7-[4-(trifluoromethyl)coumarin]acrylamide and studied. Daphnia magna, Corophium volutator, and Vibrio fischeri were employed in a series of standard acute ecotoxicity tests, being exposed to the PNPs at 3 different environmentally realistic concentrations (0.01 mg/L, 0.1 mg/L, and 1.0 mg/L) and a high concentration 500 mg/L to 1000 mg/L. In addition, sublethal effects of PNPs in C. volutator were determined using a sediment reburial test, and the uptake and depuration of fluorescent PNPs was studied in D. magna. The PNPs and fluorescent PNPs did not exhibit any observable toxicity at concentrations up to 500 mg/L to 1000 mg/L in any of the tests except for PMMA-PSMA PNPs and fluorescent PNPs following 48-h exposure to D. magna (median lethal concentration values of 879 mg/L and 887 mg/L, respectively). No significant differences were observed between labeled and nonlabeled PNPs, indicating the suitability of using fluorescent labeling. Significant uptake and rapid excretion of the fluorescent PNPs was observed in D. magna. Environ Toxicol Chem 2016;35:1641-1649. © 2015 SETAC.

  2. VASCULAR PLANTS AS ENGINEERS OF OXYGEN IN AQUATIC SYSTEMS

    EPA Science Inventory

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  4. Differential Regulation by Organic Compounds and Heavy Metals of Multiple Laccase Genes in the Aquatic Hyphomycete Clavariopsis aquatica

    PubMed Central

    Solé, Magali; Müller, Ines; Pecyna, Marek J.; Fetzer, Ingo; Harms, Hauke

    2012-01-01

    To advance the understanding of the molecular mechanisms controlling microbial activities involved in carbon cycling and mitigation of environmental pollution in freshwaters, the influence of heavy metals and natural as well as xenobiotic organic compounds on laccase gene expression was quantified using quantitative real-time PCR (qRT-PCR) in an exclusively aquatic fungus (the aquatic hyphomycete Clavariopsis aquatica) for the first time. Five putative laccase genes (lcc1 to lcc5) identified in C. aquatica were differentially expressed in response to the fungal growth stage and potential laccase inducers, with certain genes being upregulated by, e.g., the lignocellulose breakdown product vanillic acid, the endocrine disruptor technical nonylphenol, manganese, and zinc. lcc4 is inducible by vanillic acid and most likely encodes an extracellular laccase already excreted during the trophophase of the organism, suggesting a function during fungal substrate colonization. Surprisingly, unlike many laccases of terrestrial fungi, none of the C. aquatica laccase genes was found to be upregulated by copper. However, copper strongly increases extracellular laccase activity in C. aquatica, possibly due to stabilization of the copper-containing catalytic center of the enzyme. Copper was found to half-saturate laccase activity already at about 1.8 μM, in favor of a fungal adaptation to low copper concentrations of aquatic habitats. PMID:22544244

  5. Revisiting the concept of recalcitrance and organic matter persistence in soils and aquatic systems: Does environment trump chemistry?

    NASA Astrophysics Data System (ADS)

    Marin-Spiotta, E.

    2014-12-01

    Most ecological models of decomposition rely on plant litter chemistry. However, growing evidence suggests that the chemical composition of organic matter (OM) is not a good predictor of its eventual fate in terrestrial or aquatic environments. New data on variable decomposition rates of select organic compounds challenge concepts of chemical recalcitrance, i.e. the inherent ability of certain molecular structures to resist biodegradation. The role of environmental or "ecosystem" properties on influencing decomposition dates back to some of the earliest research on soil OM. Despite early recognition that the physical and aqueous matrices are critical in determining the fate of organic compounds, the prevailing paradigm hinges on intrinsic chemical properties as principal predictors of decay rate. Here I build upon recent reviews and discuss new findings that contribute to three major transformations in our understanding of OM persistence: (1) a shift away from an emphasis on chemical recalcitrance as a primary predictor of turnover, (2) new interpretations of radiocarbon ages which challenge predictions of reactivity, and (3) the recognition that most detrital OM accumulating in soils and in water has been microbially processed. Predictions of OM persistence due to aromaticity are challenged by high variability in lignin and black C turnover observed in terrestrial and aquatic environments. Contradictions in the behavior of lignin are, in part, influenced by inconsistent methodologies among research communities. Even black C, long considered to be one of the most recalcitrant components of OM, is susceptible to biodegradation, challenging predictions of the stability of aromatic structures. At the same time, revised interpretations of radiocarbon data suggest that organic compounds can acquire long mean residence times by various mechanisms independent of their molecular structure. Understanding interactions between environmental conditions and biological

  6. Toxicological assessment of indium nitrate on aquatic organisms and investigation of the effects on the PLHC-1 fish cell line.

    PubMed

    Zurita, Jorge L; Jos, Angeles; del Peso, Ana; Salguero, Manuel; Cameán, Ana M; López-Artíguez, Miguel; Repetto, Guillermo

    2007-11-15

    Indium nitrate is mainly used as a semiconductor in batteries, for plating and other chemical and medical applications. There is a lack of available information about the adverse effects of indium compounds on aquatic organisms. Therefore, the toxic effects on systems from four trophic levels of the aquatic ecosystem were investigated. Firstly, the bacterium Vibrio fischeri, the alga Chlorella vulgaris and the cladoceran Daphnia magna were used in the toxicological evaluation of indium nitrate. The most sensitive model was V. fischeri, with a NOAEL of 0.02 and an EC(50) of 0.04 mM at 15 min. Although indium nitrate should be classified as harmful to aquatic organisms, it is not expected to represent acute risk to the aquatic biota. Secondly, PLHC-1 fish cell line was employed to investigate the effects and mechanisms of toxicity. Although protein content, neutral red uptake, methylthiazol metabolization, lysosomal function and acetylcholinesterase activity were reduced in cells, stimulations were observed for metallothionein levels and succinate dehydrogenase and glucose-6-phosphate dehydrogenase activities. No changes were observed in ethoxyresorufin-O-deethylase activity. To clarify the main events in PLHC-1 cell death induced by indium nitrate, nine modulators were applied. They were related to oxidative stress (alpha-tocopherol succinate, mannitol and sodium benzoate), disruption of calcium homeostasis (BAPTA-AM and EGTA), thiol protection (1,4-dithiotreitol), iron chelation (deferoxiamine) or regulation of glutathione levels (2-oxothiazolidine-4-carboxylic acid and malic acid diethyl ester). The main morphological alterations were hydropic degeneration and loss of cells. At least, in partly, toxicity seems to be mediated by oxidative stress, and particularly by NADPH-dependent lipid peroxidation.

  7. Chemical Composition of Aquatic Dissolved Organic Matter in Five Boreal Forest Catchments Sampled in Spring and Fall Seasons

    SciTech Connect

    Schumacher,M.; Christl, I.; Vogt, R.; Barmettler, K.; Jacobsen, C.; Kretzschmar, R.

    2006-01-01

    The chemical composition and carbon isotope signature of aquatic dissolved organic matter (DOM) in five boreal forest catchments in Scandinavia were investigated. The DOM was isolated during spring and fall seasons using a reverse osmosis technique. The DOM samples were analyzed by elemental analysis, FT-IR, solid-state CP-MAS {sup 13}C-NMR, and C-1s NEXAFS spectroscopy. In addition, the relative abundance of carbon isotopes ({sup 12}C, {sup 13}C, {sup 14}C) in the samples was measured. There were no significant differences in the chemical composition or carbon isotope signature of the DOM sampled in spring and fall seasons. Also, differences in DOM composition between the five catchments were minor. Compared to reference peat fulvic and humic acids, all DOM samples were richer in O-alkyl carbon and contained less aromatic and phenolic carbon, as shown by FT-IR, {sup 13}C-NMR, and C-1s NEXAFS spectroscopy. The DOM was clearly enriched in {sup 14}C relative to the NBS oxalic acid standard of 1950, indicating that the aquatic DOM contained considerable amounts of organic carbon younger than about 50 years. The weight-based C:N ratios of 31 {+-} 6 and the {delta}{sup 13}Cvalues of -29 {+-} 2{per_thousand}indicate that the isolated DOM is of terrestrial rather than aquatic origin. We conclude that young, hydrophilic carbon compounds of terrestrial origin are predominant in the samples investigated, and that the composition of the aquatic DOM in the studied boreal forest catchments is rather stable during low to intermediate flow conditions.

  8. Behavior persistence in defining threshold switch in stepwise response of aquatic organisms exposed to toxic chemicals.

    PubMed

    Ren, Zongming; Li, Shangge; Zhang, Tingting; Qi, Luhuizi; Xing, Na; Yu, Huimin; Jian, Jinfeng; Chon, Tae-Soo; Tang, Bo

    2016-12-01

    As a characteristic in bacterial colony, persistence model described the dynamics of two subpopulations (normal (n) and persister (p)). In order to illustrate the switch of "Threshold" in the stepwise behavior responses of organisms, it is hypothesized that total behavior (Bt) of organisms consists of two types in behavior tendency, intoxication (Bp) and normal/recovery behavior (Bn). Both Bp and Bn could be concurrently affected by environmental stress E, and behavior response modes (M) are decided by the relationship between E and toxicity threshold of test organisms (Ti). The results suggested stress constant λ was decided by the constant rates gnE,gpE, an and ap. Due to different stress constant λ, the behavior responses of indicators showed great difference in different M, which included 'safe mode' (Ms), 'acclimation mode' (Mac), 'adjustment mode' (Maj) and 'toxic effect' (Mte). Usually, Bt during Ms could maintain around 0.8, and Mte would happen once it is lower than 0.2. According to the relationship between Bt values and E changes in 7 Majs, behavior persistence relying on adjustment could reflect the behavior homeostasis of organisms under environmental stress and be regarded as a threshold switch for the stepwise behavior responses. The mathematical analysis of behavior persistence allows making a quantitative prediction on environment assessment that would promote the emergence of persistence, as well as evaluating its ecological implications.

  9. Bioconcentration of the intense sweetener sucralose in a multitrophic battery of aquatic organisms.

    PubMed

    Lillicrap, Adam; Langford, Katherine; Tollefsen, Knut Erik

    2011-03-01

    Reports of the intense (artificial) sweetener sucralose (1,6-dichloro-1,6-dideoxy-β-D-fructo-furanosyl 4-chloro-4-deoxy-α-D-galactopyranoside) in various environmental compartments have led to speculations about biological effects in nontarget species living in areas receiving discharges from anthropogenic activities. We have, as the first step in the risk assessment of this compound, conducted bioaccumulation studies in the freshwater alga Pseudokirchneriella subcapitata, the crustacean Daphnia magna, and zebrafish (Danio rerio). The freshwater algae and the daphnid tests were performed using a 48-h static exposure system, whereas the zebrafish test was performed using a 48-h semi static exposure system followed by 48 h flow-through of clean water for the depuration phase. All three studies were conducted with two exposure concentrations (10 and 100 mg/L), and the concentrations of sucralose in water and biota were verified by liquid chromatography/mass spectrometry. The studies showed that uptake of sucralose was assumed to achieve a steady state within the first 48 h, and the bioconcentration factor at the assumed steady state (BCF(SS) ) was calculated to be less than 1 for algae and between 1.6 to 2.2 for the daphnids. The fish BCF(SS), assumed to occur between 24 to 48 hours, were calculated to be less than 1 for both concentrations tested. A first-order one-compartment (uptake phase) and a first-order two-compartment (elimination phase) model characterized the uptake and depuration kinetics in zebrafish (k(1)=0.027-0.038/h and k(2)=0.206-0.222/h, t(95)=13.5 to 14.6 h, t(50)=3.1 to 3.3 h, and BCF(kinetic)=0.4 to 0.9). The current study shows that sucralose does not bioaccumulate in aquatic organisms from different tiers of the food web, and that the BCF's obtained were considerably lower than the criteria set to identify persistent, bioaccumulative, and toxic substances (i.e., BCF ≥ 2,000).

  10. 40 CFR 158.630 - Terrestrial and aquatic nontarget organisms data requirements table.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... honeybee acute contact LD50, one freshwater fish early-life stage, one freshwater invertebrate life cycle..., the freshwater invertebrate life-cycle, and the acute estuarine tests. (c) Key. R=Required; CR... 850.1300 Aquatic invertebrate life cycle (freshwater) R R R R NR NR TGAI 1, 10, 12 850.1350...

  11. 40 CFR 158.630 - Terrestrial and aquatic nontarget organisms data requirements table.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... honeybee acute contact LD50, one freshwater fish early-life stage, one freshwater invertebrate life cycle..., the freshwater invertebrate life-cycle, and the acute estuarine tests. (c) Key. R=Required; CR... 850.1300 Aquatic invertebrate life cycle (freshwater) R R R R NR NR TGAI 1, 10, 12 850.1350...

  12. 40 CFR 158.630 - Terrestrial and aquatic nontarget organisms data requirements table.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... honeybee acute contact LD50, one freshwater fish early-life stage, one freshwater invertebrate life cycle..., the freshwater invertebrate life-cycle, and the acute estuarine tests. (c) Key. R=Required; CR... 850.1300 Aquatic invertebrate life cycle (freshwater) R R R R NR NR TGAI 1, 10, 12 850.1350...

  13. Persistent organic pollutants in the Olifants River Basin, South Africa: Bioaccumulation and trophic transfer through a subtropical aquatic food web.

    PubMed

    Verhaert, Vera; Newmark, Nadine; D'Hollander, Wendy; Covaci, Adrian; Vlok, Wynand; Wepener, Victor; Addo-Bediako, Abraham; Jooste, Antoinette; Teuchies, Johannes; Blust, Ronny; Bervoets, Lieven

    2017-05-15

    This study investigates the trophic transfer of persistent organic pollutants (POPs: PCBs, PBDEs, OCPs and PFASs) in the subtropical aquatic ecosystem of the Olifants River Basin (South Africa) by means of trophic magnification factors (TMFs). Relative trophic levels were determined by stable isotope analysis. POP levels in surface water, sediment and biota were low. Only ∑DDTs levels in fish muscle (1, indicating biomagnification of all detected POPs. Calculated TMFs for PCBs were comparable to TMF values reported from the tropical Congo River basin and lower than TMFs from temperate and arctic regions. For p,p'-DDT, a higher TMF value was observed for the subtropical Olifants River during the winter low flow season than for the tropical Congo river. TMFs of DDTs from the present study were unexpectedly higher than TMFs from temperate and arctic aquatic food webs. The fish species in the aquatic ecosystem of the Olifants River can be consumed with a low risk for POP contamination.

  14. An approach for calculating a confidence interval from a single aquatic sample for monitoring hydrophobic organic contaminants.

    PubMed

    Matzke, Melissa M; Allan, Sarah E; Anderson, Kim A; Waters, Katrina M

    2012-12-01

    The use of passive sampling devices (PSDs) for monitoring hydrophobic organic contaminants in aquatic environments can entail logistical constraints that often limit a comprehensive statistical sampling plan, thus resulting in a restricted number of samples. The present study demonstrates an approach for using the results of a pilot study designed to estimate sampling variability, which in turn can be used as variance estimates for confidence intervals for future n = 1 PSD samples of the same aquatic system. Sets of three to five PSDs were deployed in the Portland Harbor Superfund site for three sampling periods over the course of two years. The PSD filters were extracted and, as a composite sample, analyzed for 33 polycyclic aromatic hydrocarbon compounds. The between-sample and within-sample variances were calculated to characterize sources of variability in the environment and sampling methodology. A method for calculating a statistically reliable and defensible confidence interval for the mean of a single aquatic passive sampler observation (i.e., n = 1) using an estimate of sample variance derived from a pilot study is presented. Coverage probabilities are explored over a range of variance values using a Monte Carlo simulation.

  15. Morphological evolution and reconstruction of silver nanoparticles in aquatic environments: the roles of natural organic matter and light irradiation.

    PubMed

    Zou, Xiaoyan; Shi, Junpeng; Zhang, Hongwu

    2015-07-15

    With the proliferation of silver nanoparticles (AgNPs), their potential entry into the environment has attracted increasing concern. Although photochemical transformation is an important fate of AgNPs in aquatic environments due to their strong light absorption, little is known about the evolution and transformation mechanisms of AgNPs. This study investigated the morphological evolution and reconstruction of AgNPs during photoconversion in the presence of natural organic matter (NOM). In the dark, the AgNPs formed chain-like structures through bridging effects with NOM at concentrations of 0.1 and 1 mg/L, and the proportion of Ag(+) in solution in the presence of 10 mg/L NOM was reduced by roughly half compared with that in the absence of NOM. Under irradiation, NOM participated in the photoreaction of AgNPs and can decelerate the photoreaction of AgNPs via several mechanisms, including light attenuation, the formation of a NOM coating, and competing with Ag for photons. Additionally, NOM can substitute for citrate as a stabilizing agent to compensate for the loss of AgNP stability due to citrate mineralization under extended irradiation, producing stable triangular nanosilver in aquatic environments. This study sheds light on the behavioral differences of AgNPs in different aquatic systems, which create uncertainties and difficulties in assessing the environmental risks of AgNPs.

  16. Release of copper from sintered tungsten-bronze shot under different pH conditions and its potential toxicity to aquatic organisms.

    PubMed

    Thomas, Vernon G; Santore, Robert C; McGill, Ian

    2007-03-01

    Sintered tungsten-bronze is a new substitute for lead shot, and is about to be deposited in and around the wetlands of North America. This material contains copper in the alloyed form of bronze. This in vitro study was performed according to U.S. Fish and Wildlife Service criteria to determine the dissolution rate of copper from the shot, and to assess the toxic risk that it may present to aquatic organisms. The dissolution of copper from tungsten-bronze shot, pure copper shot, and glass beads was measured in a buffered, moderately hard, synthetic water of pH 5.5, 6.6, and 7.8 over a 28-day period. The dissolution of copper from both the control copper shot and the tungsten-bronze shot was affected significantly by the pH of the water and the duration of dissolution (all p values<0.000). The rate of copper release from tungsten bronze shot was 30 to 50 times lower than that from the copper shot, depending on pH (p<0.0000). The observed expected environmental concentration of copper released from tungsten-bronze shot after 28 days was 0.02 microg/L at pH 7.8, and 0.4 microg/L at pH 5.6, using a loading and exposure scenario specific in a U.S. Fish and Wildlife Service protocol. Ratio Quotient values derived from the highest EEC observed in this study (0.4 microg/L), and the copper toxic effect levels for all aquatic species listed in the U.S. Environmental Protection Agency ambient water quality criteria database, were all far less than the 0.1 criterion value. Given the conditions stipulated by the U.S. Fish and Wildlife Service and the U.S. Environmental Protection Agency, heavy loading from discharged tungsten-bronze shot would not pose a toxic risk to potable water, or to soil. Consequently, it would appear that no toxic risks to aquatic organisms will attend the use of tungsten-bronze shot of the approved composition. Given the likelihood that sintered tungsten-bronze of the same formula will be used for fishing weights, bullets, and wheel balance weights, it

  17. Exposures of aquatic organisms to the organophosphorus insecticide, chlorpyrifos resulting from use in the United States.

    PubMed

    Williams, W Martin; Giddings, Jeffrey M; Purdy, John; Solomon, Keith R; Giesy, John P

    2014-01-01

    Concentrations of CPY in surface waters are an integral determinant of risk to aquatic organisms. CPY has been measured in surface waters of the U.S. in several environmental monitoring programs and these data were evaluated to characterize concentrations, in relation to major areas of use and changes to the label since 2001, particularly the removal of domestic uses. Frequencies of detection and 95th centile concentrations of CPY decreased more than fivefold between 1992 and 2010. Detections in 1992-2001 ranged from 10.2 to 53%, while 2002-2010 detections ranged from 7 to 11%. The 95th centile concentrations ranged from 0.007 to 0.056 j.lg L -I in 1992-2001 and 0.006-0.008 j.lg L -I in 2002-2010.The greatest frequency of detections occurred in samples from undeveloped and agricultural land-use classes. Samples from urban and mixed land-use classes had the smallest frequency of detections and 95th centile concentrations, consistent with the cessation of most homeowner uses in 2001. The active metabolite of CPY, CPYO, was not detected frequently or in large concentrations. In 10,375 analyses from several sampling programs conducted between 1999 and 2012, only 25 detections (0.24% of samples) of CPYO were reported and estimated concentrations were less than the LOQ.Although the monitoring data on CPY provide relevant insight in quantifying the range of concentrations in surface waters, few monitoring programs have sampled at a frequency sufficient to quantify the time-series pattern of exposure. Therefore,numerical simulations were used to characterize concentrations of CPY in water and sediment for three representative high exposure environments in the U.S. Thefate of CPY in the environment is dependent on a number of dissipation and degradation processes. In terms of surface waters, fate in soils is a major driver of the potential for runoff into surface waters and results from a number of dissipation studies in the laboratory were characterized. Aerobic

  18. Effect of soil sorption and aquatic natural organic matter on the antibacterial activity of a fullerene water suspension.

    PubMed

    Li, Dong; Lyon, Delina Y; Li, Qilin; Alvarez, Pedro J J

    2008-09-01

    The present study investigated the association of a C60 water suspension (nC6) with natural organic matter, present as a soil constituent or dissolved in the water column, and its effect on the antibacterial activity of nC60. Sorption of nC60 to soil reduced its bioavailability and antibacterial activity, and the sorption capacity strongly depended on the organic content of the soil. Adsorption of aquatic dissolved humic substances onto nC60 and possible subsequent reactions also were found to eliminate nC60 toxicity at humic acid concentrations as low as 0.05 mg/L. These findings indicate that natural organic matter in the environment can mitigate significantly the potential impacts of nC60 on microbial activities that are important to ecosystem health.

  19. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus

    PubMed Central

    Laarhoven, Bob; Elissen, H. J. H.; Temmink, H.; Buisman, C. J. N.

    2016-01-01

    An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv). The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml), 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin). With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates. PMID:26937632

  20. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus.

    PubMed

    Laarhoven, Bob; Elissen, H J H; Temmink, H; Buisman, C J N

    2016-01-01

    An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv). The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml), 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin). With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates.

  1. A simultaneous multiple species acute toxicity test comparing relative sensitivities of six aquatic organisms to HgCl{sub 2}

    SciTech Connect

    McCrary, J.E.; Heagler, M.G.

    1995-12-31

    In the last few years there has been concern in the scientific community about observed declines in some amphibian species. These population declines could be reflecting a global phenomenon due to a general class sensitivity or may be part of a natural cycle. The suggestion of an overall greater sensitivity of amphibians is not supported. Studies show that amphibians, as a class, are neither more or less susceptible than fish to environmental conditions. Mercury has been found to be one of the most toxic of the heavy metals introduced into amphibian breeding waters. Six aquatic species were simultaneously exposed in a comparative acute toxicity test with mercury chloride: three amphibians, Rana catesbeiana (bullfrog), R. clamitans (green frog), and R. sphenocephala (southern leopard frog, formally classified as R. utricularia); two fish, Gambusia affinis (mosquitofish) and Notemigonus crysoleucas (golden shiner); one aquatic aligochaete, Lumbriculus variegatus (aquatic earthworm). The five test concentrations used were 1.4, 3.9, 12.0, 110.0, and 487.0 {micro}g Hg/L respectively. Ten organisms per species were randomly placed into the six test tanks (control and five concentrations), each species in a separate chamber. The resultant LC50-96hr values produced the following rank order: R. sphenocephala, 6.59 {micro}g Hg/L; R. clamitans, 14.7 {micro}g Hg/L; N. crysoleucas, 16.75 {micro}g Hg/L; L. variegatus, 43.72,ug Hg/L; G. affinis, 52.62 {micro}g Hg/L; R. catesbeiana, 63.36 {micro}g Hg/L. No general organism class sensitivity trend, for amphibians, was developed from this data, contrary to the implicit suggestions of some researchers.

  2. Viral ecology of organic and inorganic particles in aquatic systems: avenues for further research

    PubMed Central

    Weinbauer, M.G.; Bettarel, Y.; Cattaneo, R.; Luef, B.; Maier, C.; Motegi, C.; Peduzzi, P.; Mari, X.

    2016-01-01

    Viral abundance and processes in the water column and sediments are well studied for some systems; however, we know relatively little about virus–host interactions on particles and how particles influence these interactions. Here we review virus–prokaryote interactions on inorganic and organic particles in the water column. Profiting from recent methodological progress, we show that confocal laser scanning microscopy in combination with lectin and nucleic acid staining is one of the most powerful methods to visualize the distribution of viruses and their hosts on particles such as organic aggregates. Viral abundance on suspended matter ranges from 105 to 1011 ml−1. The main factors controlling viral abundance are the quality, size and age of aggregates and the exposure time of viruses to aggregates. Other factors such as water residence time likely act indirectly. Overall, aggregates appear to play a role of viral scavengers or reservoirs rather than viral factories. Adsorption of viruses to organic aggregates or inorganic particles can stimulate growth of the free-living prokaryotic community, e.g. by reducing viral lysis. Such mechanisms can affect microbial diversity, food web structure and biogeochemical cycles. Viral lysis of bacterio- and phytoplankton influences the formation and fate of aggregates and can, for example, result in a higher stability of algal flocs. Thus, viruses also influence carbon export; however, it is still not clear whether they short-circuit or prime the biological pump. Throughout this review, emphasis has been placed on defining general problems and knowledge gaps in virus–particle interactions and on providing avenues for further research, particularly those linked to global change. PMID:27478304

  3. Humic substances alleviate the aquatic toxicity of polyvinylpyrrolidone-coated silver nanoparticles to organisms of different trophic levels.

    PubMed

    Wang, Zhuang; Quik, Joris T K; Song, Lan; Van Den Brandhof, Evert-Jan; Wouterse, Marja; Peijnenburg, Willie J G M

    2015-06-01

    The present study investigated how humic substances (HS) modify the aquatic toxicity of silver nanoparticles (AgNPs) as these particles agglomerate in water and interact with HS. An alga species (Raphidocelis subcapitata), a cladoceran species (Chydorus sphaericus), and a freshwater fish larva (Danio rerio), representing organisms of different trophic levels, were exposed to colloids of the polyvinylpyrrolidone-coated AgNPs in the presence and absence of HS. Results show that the presence of HS alleviated the aquatic toxicity of the AgNP colloids to all the organisms in a dose-dependent manner. The particle size distribution of the AgNPs' colloidal particles shifted to lower values due to the presence of HS, implying that the decrease in the toxicity of the AgNP colloids cannot be explained by the variation of agglomeration size. The surface charge of the AgNPs was found to be more negative in the presence of high concentrations of HS, suggesting an electrostatic barrier by which HS might limit interactions between particles and algae cells; indeed, this effect reduced the algae toxicity. Observations on silver ions (Ag(+)) release show that HS inhibit AgNP dissolution, depending on the concentrations of HS. When toxic effects were expressed as a function of each Ag-species, toxicity of the free Ag(+) was found to be much higher than that of the agglomerated particles.

  4. Phototransformation of carboxin in water. Toxicity of the pesticide and its sulfoxide to aquatic organisms.

    PubMed

    DellaGreca, Marina; Iesce, Maria Rosaria; Cermola, Flavio; Rubino, Maria; Isidori, Marina

    2004-10-06

    Sunlight exposure of aqueous suspensions of carboxin (1) causes its phototransformation to sulfoxide 2 and minor components. Similar effects are observed in the presence of humic acid or nitrate or at different pH values. Photoproducts 2-9 were isolated by chromatographic techniques and/or identified by spectroscopic means. Carboxin 1 and its main photoproduct sulfoxide 2 were tested to evaluate acute toxicity to primary consumers typical of the aquatic environment: the rotifer Brachionus calyciflorus and two crustaceans, Daphnia magna and Thamnocephalus platyurus. Chronic tests comprised a producer, the alga Pseudokirchneriella subcapitata, and a consumer, the crustacean Ceriodaphnia dubia.

  5. Scoping assessment of radiological doses to aquatic organisms and wildlife -- N Springs

    SciTech Connect

    Poston, T.M.; Soldat, J.K.

    1992-10-01

    Estimated does rates were determined for endemic biota inhabiting the N Springs area based primarily on spring water data collected from the first 6 months of 1991. Radiological dose estimates were computed from measured values of specific radionuclides and modeled levels of radionuclides using established computer codes. The highest doses were predicted in hypothetical populations of clams, fish-eating ducks, and rabbits. The calculated dose estimates did not exceed 1 rad/d, an administrative dose rate established by the US Department of Energy for the protection of native aquatic biota. An administrative dose rate has not been established for terrestrial wildlife.

  6. Scoping assessment of radiological doses to aquatic organisms and wildlife -- N Springs. [N Springs

    SciTech Connect

    Poston, T.M.; Soldat, J.K.

    1992-10-01

    Estimated does rates were determined for endemic biota inhabiting the N Springs area based primarily on spring water data collected from the first 6 months of 1991. Radiological dose estimates were computed from measured values of specific radionuclides and modeled levels of radionuclides using established computer codes. The highest doses were predicted in hypothetical populations of clams, fish-eating ducks, and rabbits. The calculated dose estimates did not exceed 1 rad/d, an administrative dose rate established by the US Department of Energy for the protection of native aquatic biota. An administrative dose rate has not been established for terrestrial wildlife.

  7. Long-term effects of dredging operations program: Assessing bioaccumulation in aquatic organisms exposed to contaminated sediments. Final report

    SciTech Connect

    Clarke, J.U.; McFarland, V.A.

    1991-07-01

    This paper synthesizes previous work on bioaccumulation to provide a working document for the environmental impact on the aquatic environment due to bioaccumulation of sediment contaminants resulting from dredging operations and dredged material placement. Emphasis is placed on explanation of basic concepts concerning, and factors influencing, sediment contaminant bioaccumulation and bioavailability. The paper presents several numerical methods for assessing bioaccumulation, including a simple method for estimating theoretical bioaccumulation potential (TBP) from sediment chemistry for neutral organic chemicals. Methods are also given for projecting contaminant concentrations in organism tissues when steady state is achieved, based on laboratory or field exposures to contaminated sediments. These assessments are presented in the context of the US Environmental Protection Agency's tiered testing approach for dredged material evaluation. The various numerical methods for bioaccumulation assessment are illustrated and compared using step-by-step example calculations with hypothetical and actual data.

  8. Organic trace pollutants in the aquatic environment--regulatory and technical problem-solving approaches in Germany and China.

    PubMed

    Koester, Stephan; Beier, Silvio; Zhao, Fang Fang; Sui, Qian; Yu, Gang; Pinnekamp, Johannes

    2012-01-01

    In recent years, worldwide awareness of an aquatic environment polluted by organic trace pollutants, e.g. pharmaceutical residues and industrial chemicals, has risen tremendously. The present paper outlines similarities and differences in how to face the organic trace pollutants occurring in the natural and urban water cycles in Germany and China. Our joint review clearly shows that this emerging environmental problem is in both countries being widely discussed on a scientific level and it is evidently perceived in a comparable way. However, while the state of knowledge, which is still unsatisfactory, induces further investigations in China, the research activities in Germany have already led to first full-scale applications to remove trace pollutants. While Germany seems to be one step ahead, China possibly is in a better position for a later trace pollutants removal due to the massively increasing use of membrane bioreactors as a key technology for the necessary expansion of wastewater treatment capacities.

  9. How Are Changing Solar Ultraviolet Radiation and Climate Affecting Light-induced Chemical Processes in Aquatic Environments?

    EPA Science Inventory

    Changes in the ozone layer over the past three decades have resulted in increases in solar UV-B radiation (280-315 nm) that reach the surface of aquatic environments. These changes have been accompanied by unprecedented changes in temperature and precipitation patterns around the...

  10. PROCEEDINGS OF A SYMPOSIUM ON COOLING WATER INTAKE TECHNOLOGIES TO PROTECT AQUATIC ORGANISMS

    EPA Science Inventory

    This Symposium brought together professionals from federal, state, and tribal regulatory agencies; industry; environmental organizations; engineering consulting firms; science and research organizations; academia; and other organizations concerned with mitigating harm to the aqua...

  11. Evaluating the Relationship between Equilibrium Passive Sampler Uptake and Aquatic Organism Bioaccumulation

    EPA Science Inventory

    This Critcal Review evaluates passive sampler uptake of hydrophobic organic contaminants (HOCs) in water column and interstitial water exposures as a surrogate for organism bioaccumulation. Fifty-seven studies were found where both passive sampler uptake and organism bioaccumulat...

  12. Evaluating the Relationship between Equilibrium Passive Sampler Uptake and Aquatic Organism Bioaccumulation..

    EPA Science Inventory

    This review evaluates passive sampler uptake of hydrophobic organic contaminants (HOCs) in water column and interstitial water exposures as a surrogate for organism bioaccumulation. Fifty-four studies were found where both passive sampler uptake and organism bioaccumulation wer...

  13. Comparative transcriptome analysis between aquatic and aerial breathing organs of Channa argus to reveal the genetic basis underlying bimodal respiration.

    PubMed

    Jiang, Yanliang; Feng, Shuaisheng; Xu, Jian; Zhang, Songhao; Li, Shangqi; Sun, Xiaoqing; Xu, Peng

    2016-10-01

    Aerial breathing in fish was an important adaption for successful survival in hypoxic water. All aerial breathing fish are bimodal breathers. It is intriguing that they can obtain oxygen from both air and water. However, the genetic basis underlying bimodal breathing has not been extensively studied. In this study, we performed next-generation sequencing on a bimodal breathing fish, the Northern snakehead, Channa argus, and generated a transcriptome profiling of C. argus. A total of 53,591 microsatellites and 26,378 SNPs were identified and classified. A Ka/Ks analysis of the unigenes indicated that 63 genes were under strong positive selection. Furthermore, the transcriptomes from the aquatic breathing organ (gill) and the aerial breathing organ (suprabranchial chamber) were sequenced and compared, and the results showed 1,966 genes up-regulated in the gill and 2,727 genes up-regulated in the suprabranchial chamber. A gene pathway analysis concluded that four functional categories were significant, of which angiogenesis and elastic fibre formation were up-regulated in the suprabranchial chamber, indicating that the aerial breathing organ may be more efficient for gas exchange due to its highly vascularized and elastic structure. In contrast, ion uptake and transport and acid-base balance were up-regulated in the gill, indicating that the aquatic breathing organ functions in ion homeostasis and acid-base balance, in addition to breathing. Understanding the genetic mechanism underlying bimodal breathing will shed light on the initiation and importance of aerial breathing in the evolution of vertebrates.

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

    PubMed

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

    2016-02-01

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

  15. Codependency in nurses. How it affects your organization.

    PubMed

    Wise, B; Ferreiro, B

    1995-09-01

    Codependence in a staff nurse affects both direct patient care and relationships with coworkers, physicians, and supervisors. Codependent behaviors negatively impact the nurse's sphere of influence. The nurse manager's codependency has the same impact, but the sphere of influence is larger and thus, the potential for harm is greater. Codependent behaviors enacted at different levels of an organization can disrupt an entire institution or profession. The author describes how nurses' practices are affected by codependent behaviors and identifies ways in which those behaviors can be modified by good management.

  16. From a microcosm to the catchment scale: studying the fate of organic runoff pollutants in aquatic ecosystems

    NASA Astrophysics Data System (ADS)

    Böttcher, T.; Schroll, R.

    2009-04-01

    Spray-drift, drainage, erosion and runoff events are the major causes responsible for deportation of agrochemicals as micropollutants to aquatic non-target sites. These processes can lead to the contamination of nearby freshwater ecosystems with considerably high concentrations of xenobiotics. Thus, it is important to unravel the fate of these pollutants and to evaluate their ecological effects. A novel approach to address this goal was established by the development of a microcosm with multiple sampling abilities enabling quantitative assessment of organic volatilisation, mineralization, metabolization and distribution within the aquatic ecosystem. This microcosm system was designed to support modelling approaches of the catchment scale and gain insights into the fate of pesticides simulating a large scale water body. The potential of this microcosm was exemplified for Isoproturon (IPU), a phenylurea derived systemic herbicide, which is frequently found as contaminant in water samples and with the free-floating macrophyte Lemna minor as non-target species, that is common to occur in rural water bodies. During 21 days exposure time, only a small amount of 14C labeled IPU was removed from the aquatic medium. The major portion (about 5%) was accumulated by Lemna minor resulting in a BCF of 15.8. IPU-volatilisation was very low with 0.13% of the initially applied herbicide. Only a minor amount of IPU was completely metabolized, presumably by rhizosphere microorganisms and released as 14CO2. The novel experimental system allowed to quantitatively investigate the fate of IPU and showed a high reproducibility with a mean average 14C-recovery rate of 97.1

  17. Mercury Photolytic Transformation Affected by Low-Molecular-Weight Natural Organics in Water

    SciTech Connect

    He, Feng; Zheng, Wang; Gu, Baohua; Liang, Liyuan

    2012-01-01

    Mechanisms by which dissolved organic matter (DOM) mediates the photochemical reduction of Hg(II) in aquatic ecosystems are not fully understood, owing to the heterogeneous nature and complex structural properties of DOM. In this work, naturally occurring aromatic compounds including salicylic, 4-hydrobenzoic, anthranilic, 4-aminobenzoic, and phthalic acid were systematically studied as surrogates for DOM in order to gain an improved mechanistic understanding of these compounds in the photoreduction of Hg(II) in water. We show that the photoreduction rates of Hg(II) are influenced not only by the substituent functional groups such as OH, NH2 and COOH on the benzene ring, but also the positioning of these functional groups on the ring structure. The Hg(II) photoreduction rate decreases in the order anthranilic acid > salicylic acid > phthalic acid according to the presence of the NH2, OH, COOH functional groups on benzoic acid. The substitution position of the functional groups affects reduction rates in the order anthranilic acid > 4-aminobenzoic acid and salicylic acid > 4-hydroxybenzoic acid. Reduction rates correlate strongly with ultraviolet (UV) absorption of these compounds and their concentrations, suggesting that the formation of organic free radicals during photolysis of these compounds is responsible for Hg(II) photoreduction. These results provide insight into the role of low-molecular-weight organic compounds and possibly DOM in Hg photoredox transformation and may thus have important implications for understanding Hg geochemical cycling in the environment.

  18. Dissipation of a commercial mixture of polyoxyethylene amine surfactants in aquatic outdoor microcosms: Effect of water depth and sediment organic carbon.

    PubMed

    Rodriguez-Gil, Jose Luis; Lissemore, Linda; Solomon, Keith; Hanson, Mark

    2016-04-15

    This study optimized existing analytical approaches and characterized the effect of sediment total organic carbon (0.05-2.05% TOC), and water depth (15, 30, and 90cm) on the fate of MON 0818, a commercial mixture of polyoxyethylene amine surfactants (POEAs), in outdoor microcosms. Mixtures of POEAs are commonly used as adjuvants in commercial herbicide formulations containing glyphosate. Until recently, analytical methods sensitive enough to monitor environmental concentrations of POEAs in aquatic systems were not available. After optimizing recently developed analytical methods, we found that the combined use of accelerated solvent extraction (ASE) and liquid chromatography-tandem mass spectrometry provided a reliable approach for determining the concentration of sediment-adsorbed POEAs. The surfactant showed strong affinity for sediment materials, with low maximum recoveries by ASE of 52%. Under microcosm conditions, water depth or sediment characteristics did not significantly affect the water-column half-life of POEA, which ranged from 3.2 to 5.3h. Binding of POEAs to suspended solids was observed, which dissipated via one- or two-phase exponential decay; when two-phase decay occurred, fast phase half-life values ranged from 0.71 to 1.3h and slow-phase values ranged from 18 to 44h. Concentrations of POEA increased in sediment shortly after application and decreased over the study period with a half-life of 5.8 to 71d. The concentrations of POEAs in the sediment of the shallow (15cm) ponds dissipated following a two-phase exponential decay model with an initial fast-phase half-life of 1.1 to 8.9d and a slower second-phase half-life of 21d. Our results suggest that aquatic organisms are unlikely to be exposed to POEAs in aqueous phase for periods of more than a few hours following an over-water application, and that sediment is a significant sink for POEAs in aquatic systems.

  19. U.S. federal policies, legislation, and responsibilities related to importation of exotic fishes and other aquatic organisms

    USGS Publications Warehouse

    Stanley, Jon G.; Peoples, Robert A.; McCann, James A.

    1991-01-01

    Within the Federal government, the U. S. Fish and Wildlife Service (Service) has primary responsibility for legal and policy responsibility for introduced exotic species. The Lacey Act of 1900 authorizes the Service to prohibit the importation of species that are potentially injurious to native fish and wildlife. However, regulations under authority of the Lacey Act cover only a few species. The Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 established a Task Force co-chaired by the Director of the Service and Under Secretary of Commerce for Oceans and Atmosphere. The Task Force consults with the Secretary of Transportation to develop regulations to prevent the importation and spread of aquatic nuisance species into the Great Lakes through exchange of ballast water. Federal agencies must comply with Presidential Executive Order 1198, Exotic Organisms, that prohibits Federal agencies or activities they fund or authorize from introducing exotic species. The Service conducts research and evaluation of exotic species to support Federal, State, and local efforts to prevent further importation of harmful species. Effective regulation will also depend on the full cooperation with Canada.

  20. Genetically modified crops and aquatic ecosystems: considerations for environmental risk assessment and non-target organism testing.

    PubMed

    Carstens, Keri; Anderson, Jennifer; Bachman, Pamela; De Schrijver, Adinda; Dively, Galen; Federici, Brian; Hamer, Mick; Gielkens, Marco; Jensen, Peter; Lamp, William; Rauschen, Stefan; Ridley, Geoff; Romeis, Jörg; Waggoner, Annabel

    2012-08-01

    Environmental risk assessments (ERA) support regulatory decisions for the commercial cultivation of genetically modified (GM) crops. The ERA for terrestrial agroecosystems is well-developed, whereas guidance for ERA of GM crops in aquatic ecosystems is not as well-defined. The purpose of this document is to demonstrate how comprehensive problem formulation can be used to develop a conceptual model and to identify potential exposure pathways, using Bacillus thuringiensis (Bt) maize as a case study. Within problem formulation, the insecticidal trait, the crop, the receiving environment, and protection goals were characterized, and a conceptual model was developed to identify routes through which aquatic organisms may be exposed to insecticidal proteins in maize tissue. Following a tiered approach for exposure assessment, worst-case exposures were estimated using standardized models, and factors mitigating exposure were described. Based on exposure estimates, shredders were identified as the functional group most likely to be exposed to insecticidal proteins. However, even using worst-case assumptions, the exposure of shredders to Bt maize was low and studies supporting the current risk assessments were deemed adequate. Determining if early tier toxicity studies are necessary to inform the risk assessment for a specific GM crop should be done on a case by case basis, and should be guided by thorough problem formulation and exposure assessment. The processes used to develop the Bt maize case study are intended to serve as a model for performing risk assessments on future traits and crops.

  1. Metacommunity ecology meets biogeography: effects of geographical region, spatial dynamics and environmental filtering on community structure in aquatic organisms.

    PubMed

    Heino, Jani; Soininen, Janne; Alahuhta, Janne; Lappalainen, Jyrki; Virtanen, Risto

    2017-01-01

    Metacommunity patterns and underlying processes in aquatic organisms have typically been studied within a drainage basin. We examined variation in the composition of six freshwater organismal groups across various drainage basins in Finland. We first modelled spatial structures within each drainage basin using Moran eigenvector maps. Second, we partitioned variation in community structure among three groups of predictors using constrained ordination: (1) local environmental variables, (2) spatial variables, and (3) dummy variable drainage basin identity. Third, we examined turnover and nestedness components of multiple-site beta diversity, and tested the best fit patterns of our datasets using the "elements of metacommunity structure" analysis. Our results showed that basin identity and local environmental variables were significant predictors of community structure, whereas within-basin spatial effects were typically negligible. In half of the organismal groups (diatoms, bryophytes, zooplankton), basin identity was a slightly better predictor of community structure than local environmental variables, whereas the opposite was true for the remaining three organismal groups (insects, macrophytes, fish). Both pure basin and local environmental fractions were, however, significant after accounting for the effects of the other predictor variable sets. All organismal groups exhibited high levels of beta diversity, which was mostly attributable to the turnover component. Our results showed consistent Clementsian-type metacommunity structures, suggesting that subgroups of species responded similarly to environmental factors or drainage basin limits. We conclude that aquatic communities across large scales are mostly determined by environmental and basin effects, which leads to high beta diversity and prevalence of Clementsian community types.

  2. Leveraging existing data for prioritization of the ecological risks of human and veterinary pharmaceuticals to aquatic organisms

    PubMed Central

    LaLone, Carlie A.; Berninger, Jason P.; Villeneuve, Daniel L.; Ankley, Gerald T.

    2014-01-01

    Medicinal innovation has led to the discovery and use of thousands of human and veterinary drugs. With this comes the potential for unintended effects on non-target organisms exposed to pharmaceuticals inevitably entering the environment. The impracticality of generating whole-organism chronic toxicity data representative of all species in the environment has necessitated prioritization of drugs for focused empirical testing as well as field monitoring. Current prioritization strategies typically emphasize likelihood for exposure (i.e. predicted/measured environmental concentrations), while incorporating only rather limited consideration of potential effects of the drug to non-target organisms. However, substantial mammalian pharmacokinetic and mechanism/mode of action (MOA) data are produced during drug development to understand drug target specificity and efficacy for intended consumers. An integrated prioritization strategy for assessing risks of human and veterinary drugs would leverage available pharmacokinetic and toxicokinetic data for evaluation of the potential for adverse effects to non-target organisms. In this reiview, we demonstrate the utility of read-across approaches to leverage mammalian absorption, distribution, metabolism and elimination data; analyse cross-species molecular target conservation and translate therapeutic MOA to an adverse outcome pathway(s) relevant to aquatic organisms as a means to inform prioritization of drugs for focused toxicity testing and environmental monitoring. PMID:25405975

  3. May organic pollutants affect fish populations in the North Sea?

    PubMed

    Hylland, Ketil; Beyer, Jonny; Berntssen, Marc; Klungsøyr, Jarle; Lang, Thomas; Balk, Lennart

    2006-01-08

    The North Sea is a highly productive area with large fish populations that have been extensively harvested over the past century. North Sea fisheries remain important to the surrounding countries despite declining fish stocks over the past decades. The main reason for declining fish stocks is nearly certainly overfishing, but other environmental pressures also affect fish populations, such as eutrophication, climate change, and exposure to metals and organic pollutants, including polyaromatic hydrocarbons (PAHs), alkylphenols, and organochlorine compounds. There are three main sources of organic pollutants in the North Sea: atmospheric, land-based sources, and inputs from offshore gas and oil installations. All three sources contribute to elevated concentrations of organic pollutants in the North Sea compared to the Norwegian Sea. There is evidence that chlorinated organic contaminants were present in sufficiently high concentrations in the southern North Sea two decades ago, to alter embryonal development in fish. The results from extensive, long-term monitoring programs show that some diseases decreased whereas other increased in the southern North Sea and that, among other factors, contaminants may play a role in the temporal changes recorded in disease prevalence. Recent studies demonstrated that components in offshore effluents may affect fish reproduction and that tissues of fish near oil rigs are structurally different to tissues of fish from reference areas. Data on effluents from offshore activities have recently become available through an international workshop (BECPELAG) and follow-up studies.

  4. Trace element accumulation and trophic relationships in aquatic organisms of the Sundarbans mangrove ecosystem (Bangladesh).

    PubMed

    Borrell, Asunción; Tornero, Victoria; Bhattacharjee, Dola; Aguilar, Alex

    2016-03-01

    The Sundarbans forest is the largest and one of the most diverse and productive mangrove ecosystems in the world. Located at the northern shoreline of the Bay of Bengal in the Indian Ocean and straddling India and Bangladesh, the mangrove forest is the result of three primary river systems that originate further north and northwest. During recent decades, the Sundarbans have been subject to increasing pollution by trace elements caused by the progressive industrialization and urbanization of the basins of these three rivers. As a consequence, animals and plants dwelling downstream in the mangroves are exposed to these pollutants in varying degrees, and may potentially affect human health when consumed. The aim of the present study was to analyse the concentrations of seven trace elements (Zn, Cu, Cr, Hg, Pb, Cd and As) in 14 different animal and plant species collected in the Sundarbans in Bangladesh to study their transfer through the food web and to determine whether their levels in edible species are acceptable for human consumption. δ(15)N values were used as a proxy of the trophic level. A decrease in Zn, Cu, Pb and Cd levels was observed with increasing trophic position. Trace element concentrations measured in all organisms were, in general, lower than the concentrations obtained in other field studies conducted in the same region. When examined with respect to accepted international standards, the concentrations observed in fish and crustaceans were generally found to be safe for human consumption. However, the levels of Zn in Scylla serrata and Cr and Cd in Harpadon nehereus exceeded the proposed health advisory levels and may be of concern for human health.

  5. Evaluating the Relationship between Equilibrium Passive Sampler Uptake and Aquatic Organism Bioaccumulation.

    EPA Science Inventory

    For decades, biomonitoring organisms have been used to assess the bioavailability of hydrophobic organic contaminants (HOCs) at contaminated sediment Superfund sites across the country. Specific applications include evaluating remedy effectiveness and pre- and post-remediation l...

  6. Evaluating the Relationship between Equilibrium Passive Sampler Uptake and Aquatic Organism Bioaccumulation,

    EPA Science Inventory

    Objectives. This review evaluates passive sampler uptake of hydrophobic organic contaminants (HOCs) in water column and interstitial water exposures as a surrogate for organism bioaccumulation. Approach/Activities. Fifty-five studies were found where both passive sampler uptake...

  7. Wastewater treatment plant effluent as a source of microplastics: review of the fate, chemical interactions and potential risks to aquatic organisms.

    PubMed

    Ziajahromi, Shima; Neale, Peta A; Leusch, Frederic D L

    2016-11-01

    Wastewater treatment plant (WWTP) effluent has been identified as a potential source of microplastics in the aquatic environment. Microplastics have recently been detected in wastewater effluent in Western Europe, Russia and the USA. As there are only a handful of studies on microplastics in wastewater, it is difficult to accurately determine the contribution of wastewater effluent as a source of microplastics. However, even the small amounts of microplastics detected in wastewater effluent may be a remarkable source given the large volumes of wastewater treatment effluent discharged to the aquatic environment annually. Further, there is strong evidence that microplastics can interact with wastewater-associated contaminants, which has the potential to transport chemicals to aquatic organisms after exposure to contaminated microplastics. In this review we apply lessons learned from the literature on microplastics in the aquatic environment and knowledge on current wastewater treatment technologies, with the aim of identifying the research gaps in terms of (i) the fate of microplastics in WWTPs, (ii) the potential interaction of wastewater-based microplastics with trace organic contaminants and metals, and (iii) the risk for aquatic organisms.

  8. How an organism dies affects the fitness of its neighbors.

    PubMed

    Durand, Pierre M; Rashidi, Armin; Michod, Richard E

    2011-02-01

    Programmed cell death (PCD), a genetically regulated cell suicide program, is ubiquitous in the living world. In contrast to multicellular organisms, in which cells cooperate for the good of the organism, in unicells the cell is the organism and PCD presents a fundamental evolutionary problem. Why should an organism actively kill itself as opposed to dying in a nonprogrammed way? Proposed arguments vary from PCD in unicells being maladaptive to the assumption that it is an extreme form of altruism. To test whether PCD could be beneficial to nearby cells, we induced programmed and nonprogrammed death in the unicellular green alga Chlamydomonas reinhardtii. Cellular contents liberated during non-PCD are detrimental to others, while the contents released during PCD are beneficial. The number of cells in growing cultures was used to measure fitness. Thermostability studies revealed that the beneficial effect of the PCD supernatant most likely involves simple heat-stable biomolecules. Non-PCD supernatant contains heat-sensitive molecules like cellular proteases and chlorophyll. These data indicate that the mode of death affects the origin and maintenance of PCD. The way in which an organism dies can have beneficial or deleterious effects on the fitness of its neighbors.

  9. Proteomics to assess the role of phenotypic plasticity in aquatic organisms exposed to pollution and global warming.

    PubMed

    Silvestre, Frédéric; Gillardin, Virginie; Dorts, Jennifer

    2012-11-01

    Nowadays, the unprecedented rates of anthropogenic changes in ecosystems suggest that organisms have to migrate to new distributional ranges or to adapt commensurately quickly to new conditions to avoid becoming extinct. Pollution and global warming are two of the most important threats aquatic organisms will have to face in the near future. If genetic changes in a population in response to natural selection are extensively studied, the role of acclimation through phenotypic plasticity (the property of a given genotype to produce different phenotypes in response to particular environmental conditions) in a species to deal with new environmental conditions remains largely unknown. Proteomics is the extensive study of the protein complement of a genome. It is dynamic and depends on the specific tissue, developmental stage, and environmental conditions. As the final product of gene expression, it is subjected to several regulatory steps from gene transcription to the functional protein. Consequently, there is a discrepancy between the abundance of mRNA and the abundance of the corresponding protein. Moreover, proteomics is closer to physiology and gives a more functional knowledge of the regulation of gene expression than does transcriptomics. The study of protein-expression profiles, however, gives a better portrayal of the cellular phenotype and is considered as a key link between the genotype and the organismal phenotype. Under new environmental conditions, we can observe a shift of the protein-expression pattern defining a new cellular phenotype that can possibly improve the fitness of the organism. It is now necessary to define a proteomic norm of reaction for organisms acclimating to environmental stressors. Its link to fitness will give new insights into how organisms can evolve in a changing environment. The proteomic literature bearing on chronic exposure to pollutants and on acclimation to heat stress in aquatic organisms, as well as potential application of

  10. Survey of aquatic macroinvertebrates and amphibians at Wupatki National Monument, Arizona, USA: An evaluation of selected factors affecting species richness in ephemeral pools

    USGS Publications Warehouse

    Graham, T.B.

    2002-01-01

    Ephemeral aquatic habitats in Wupatki National Monument vary from naturally formed pools in arroyos over 5000 years old, to constructed catchment basins with ages estimated at 60-1000+ years old, and borrow pits and stock ponds 30-60 years old. The different ages of these pools provide different histories of colonization by amphibians and aquatic invertebrates, especially temporary pool specialists such as spadefoot toads and branchiopod crustaceans. Ten pools of five different origins and ages were surveyed in August and/or September 1997 for aquatic organisms; a total of 13 surveys were conducted. Twenty-two taxa were found, with the number of species in a pool during any survey ranging from one to 10. Species composition of the communities changed from one sampling date to the next within individual pools. Community structure is an amalgam of species with different dispersal mechanisms that are influenced by different pool characteristics. Age appears to have little effect overall, but may have influenced branchiopod presence/absence. Distance to permanent water, frequency of disturbance, and current pool size were correlated with presence/absence of some species.

  11. Fluidized bed ash and passive treatment reduce the adverse effects of acid mine drainage on aquatic organisms.

    PubMed

    Porter, Clint M; Nairn, Robert W

    2010-10-15

    Elevated concentrations of acidity and metals in acid mine drainage (AMD) may be effectively addressed by active and passive treatment technologies. However, typical evaluations consider only chemical water quality with little if any regard for biological metrics. Robust evaluations including both chemical and biological indicators of water quality improvement are needed. In this study, injection of alkaline fluidized bed ash (FBA) into a flooded underground coal mine was coupled with a five-cell passive treatment system to ameliorate an abandoned AMD discharge in eastern Oklahoma. The passive system included process units promoting both aerobic and anaerobic treatment mechanisms. Resulting water quality changes and biological responses were evaluated. Organisms of two distinct functional groups (the filter-feeding mollusk Corbicula fluminea and the wide-spectrum feeding fish Lepomis macrochirus) were exposed to mine waters in several treatment cells. The combination of treatment technologies was hypothesized to limit potential negative effects on these aquatic organisms. Tissues were harvested and analyzed for concentrations of several metals (Al, Fe, Mn, Mg, Ca, Ni, Cu and Zn) of interest. Organismal responses, such as hepatosomatic index, condition factor, and condition index, did not vary significantly among organisms exposed within different treatment cells when compared to non-AMD impaired waters. Metal tissue accumulation trends, compared to aqueous concentrations, were observed for Fe, Ni and Zn. Exposure experiments with these two organisms indicated that FBA introductions coupled with passive treatment decreased the potential adverse effects of AMD to biological systems.

  12. Evaluation of the toxicity of superfine materials to change the physiological functions of aquatic organisms of different trophic levels

    NASA Astrophysics Data System (ADS)

    Morgalev, S.; Morgaleva, T.; Gosteva, I.; Morgalev, Yu

    2015-11-01

    We assessed ecological and biological effects caused by the physical and chemical properties of nanomaterials on the basis of the laboratory researches into water test-organisms of different trophic levels. We studied the physiological functions of water organisms on adding into the environment superfine materials of various chemical nature and structural characteristics: metallic nanoparticles of nikel (nNi), argentum (nAg), platinum (nPt), aurum (nAu), binary NPs (powder of titanium dioxide - nTiO2, aluminum oxide - nAl2O3, zink oxide - nZnO, silicon nitride - nSi3N4, silicon carbide (nSiC) and carbon nanotubes (BT-50, MCD- material). We observed the dependence of developing the complex of unfavourable biological effects in water plants and entomostracans’ organisms on the physical and chemical properties of superfine materials. We determined the values of NOEC, L(E)C20 and L(E)C50 for aquatic organisms of various regular groups. We found out the most vulnerable elements of the communities’ trophic structure and the possibility of a breakdown in the water ecosystem food pyramid.

  13. Ecotoxicological evaluation of sodium fluoroacetate on aquatic organisms and investigation of the effects on two fish cell lines.

    PubMed

    Zurita, Jorge L; Jos, Angeles; Cameán, Ana M; Salguero, Manuel; López-Artíguez, Miguel; Repetto, Guillermo

    2007-02-01

    Sodium monofluoroacetate (compound 1080) is one of the most potent pesticides. It is also a metabolite of many other fluorinated compounds, including anticancer agents, narcotic analgesics, pesticides or industrial chemicals. Other sources of water contamination are the atmospheric degradation of hydrofluorocarbons and hydrochlorofluorocarbons. However, there is little information available about the adverse effects of sodium fluoroacetate in aquatic organisms. Firstly, the bacterium Vibrio fischeri (decomposer), the alga Chlorella vulgaris (1st producer) and the cladoceran Daphnia magna (1st consumer) were used for the ecotoxicological evaluation of SMFA. The most sensitive models were C. vulgaris and D. magna, with a NOAEL of 0.1 and an EC50 of 0.5 mM at 72 h, respectively. According to the results after the acute exposure and due to its high biodegradation rate and low bioaccumulation potential, sodium fluoroacetate is most unlikely to produce deleterious effects to aquatic organisms. Secondly, two fish cell lines were employed to investigate the effects and mechanisms of toxicity in tissues from 2nd consumers. The hepatoma fish cell line PLHC-1 was more sensitive to SMFA than the fibroblast-like fish cell line RTG-2, being the uptake of neutral red the most sensitive bioindicator. Lysosomal function, succinate dehydrogenase and acetylcholinesterase activities were inhibited, glucose-6-phosphate dehydrogenase activity was particularly stimulated, and metallothionein and ethoxyresorufin-O-deethylase levels were not modified. Intense hydropic degeneration, macrovesicular steatosis and death mainly by necrosis but also by apoptosis were observed. Moreover, sulphydryl groups and oxidative stress could be involved in PLHC-1 cell death induced by SMFA more than changes in calcium homeostasis.

  14. Polyvinylpyrrolidone and arsenic-induced changes in biological responses of model aquatic organisms exposed to iron-based nanoparticles

    NASA Astrophysics Data System (ADS)

    Llaneza, Verónica; Rodea-Palomares, Ismael; Zhou, Zuo; Rosal, Roberto; Fernández-Pina, Francisca; Bonzongo, Jean-Claude J.

    2016-08-01

    The efficiency of zero-valent iron particles used in the remediation of contaminated groundwater has, with the emergence of nanotechnology, stimulated interest on the use of nano-size particles to take advantage of high-specific surface area and reactivity characteristics of nanoparticles (NPs). Accordingly, engineered iron-NPs are among the most widely used nanomaterials for in situ remediation. However, while several ecotoxicity studies have been conducted to investigate the adverse impacts of these NPs on aquatic organisms, research on the implications of spent iron-based NPs is lacking. In this study, a comparative approach is used, in which the biological effects of three iron-based NPs (Fe3O4 and γ-Fe2O3 NPs with particle sizes ranging from 20 to 50 nm, and Fe0-NPs with an average particle size of 40 nm) on Raphidocelis subcapitata (formely known as Pseudokirchneriella subcapitata) and Daphnia magna were investigated using both as-prepared and pollutant-doped Fe-based NPs. For the latter, arsenic (As) was used as example sorbed pollutant. The results show that improved degree of NP dispersion by use of polyvinylpyrrolidone overlapped with both increased arsenic adsorption capacity and toxicity to the tested organisms. For R. subcapitata, Fe-oxide NPs were more toxic than Fe0-NPs, due primarily to differences in the degree of NPs aggregation and ability to produce reactive oxygen species. For the invertebrate D. magna, a similar trend of biological responses was observed, except that sorption of As to Fe0-NPs significantly increased the toxic response when compared to R. subcapitata. Overall, these findings point to the need for research on downstream implications of NP-pollutant complexes generated during water treatment by injection of NPs into aquatic systems.

  15. Evidence for the aquatic binding of arsenate by natural organic matter-suspended Fe(III)

    USGS Publications Warehouse

    Ritter, K.; Aiken, G.R.; Ranville, J.F.; Bauer, M. E.; Macalady, D.L.

    2006-01-01

    Dialysis experiments with arsenate and three different NOM samples amended with Fe(III) showed evidence confirming the formation of aquatic arsenate-Fe(III)-NOM associations. A linear relationship was observed between the amount of complexed arsenate and the Fe(III) content of the NOM. The dialysis results were consistent with complex formation through ferric iron cations acting as bridges between the negatively charged arsenate and NOM functional groups and/or a more colloidal association, in which the arsenate is bound by suspended Fe(III)-NOM colloids. Sequential filtration experiments confirmed that a significant proportion of the iron present at all Fe/C ratios used in the dialysis experiments was colloidal in nature. These colloids may include larger NOM species that are coagulated by the presence of chelated Fe(III) and/or NOM-stabilized ferric (oxy)hydroxide colloids, and thus, the solution-phase arsenate-Fe(III)-NOM associations are at least partially colloidal in nature. ?? 2006 American Chemical Society.

  16. Pesticide Toxicity Index: a tool for assessing potential toxicity of pesticide mixtures to freshwater aquatic organisms

    USGS Publications Warehouse

    Nowell, Lisa H.; Norman, Julia E.; Moran, Patrick W.; Martin, Jeffrey D.; Stone, Wesley W.

    2014-01-01

    Pesticide mixtures are common in streams with agricultural or urban influence in the watershed. The Pesticide Toxicity Index (PTI) is a screening tool to assess potential aquatic toxicity of complex pesticide mixtures by combining measures of pesticide exposure and acute toxicity in an additive toxic-unit model. The PTI is determined separately for fish, cladocerans, and benthic invertebrates. This study expands the number of pesticides and degradates included in previous editions of the PTI from 124 to 492 pesticides and degradates, and includes two types of PTI for use in different applications, depending on study objectives. The Median-PTI was calculated from median toxicity values for individual pesticides, so is robust to outliers and is appropriate for comparing relative potential toxicity among samples, sites, or pesticides. The Sensitive-PTI uses the 5th percentile of available toxicity values, so is a more sensitive screening-level indicator of potential toxicity. PTI predictions of toxicity in environmental samples were tested using data aggregated from published field studies that measured pesticide concentrations and toxicity to Ceriodaphnia dubia in ambient stream water. C. dubia survival was reduced to ≤ 50% of controls in 44% of samples with Median-PTI values of 0.1–1, and to 0% in 96% of samples with Median-PTI values > 1. The PTI is a relative, but quantitative, indicator of potential toxicity that can be used to evaluate relationships between pesticide exposure and biological condition.

  17. Toxicity of tetramethylammonium hydroxide to aquatic organisms and its synergistic action with potassium iodide.

    PubMed

    Mori, Izumi C; Arias-Barreiro, Carlos R; Koutsaftis, Apostolos; Ogo, Atsushi; Kawano, Tomonori; Yoshizuka, Kazuharu; Inayat-Hussain, Salmaan H; Aoyama, Isao

    2015-02-01

    The aquatic ecotoxicity of chemicals involved in the manufacturing process of thin film transistor liquid crystal displays was assessed with a battery of four selected acute toxicity bioassays. We focused on tetramethylammonium hydroxide (TMAH, CAS No. 75-59-2), a widely utilized etchant. The toxicity of TMAH was low when tested in the 72 h-algal growth inhibition test (Pseudokirchneriellia subcapitata, EC50=360 mg L(-1)) and the Microtox® test (Vibrio fischeri, IC50=6.4 g L(-1)). In contrast, the 24h-microcrustacean immobilization and the 96 h-fish mortality tests showed relatively higher toxicity (Daphnia magna, EC50=32 mg L(-1) and Oryzias latipes, LC50=154 mg L(-1)). Isobologram and mixture toxicity index analyses revealed apparent synergism of the mixture of TMAH and potassium iodide when examined with the D. magna immobilization test. The synergistic action was unique to iodide over other halide salts i.e. fluoride, chloride and bromide. Quaternary ammonium ions with longer alkyl chains such as tetraethylammonium and tetrabutylammonium were more toxic than TMAH in the D. magna immobilization test.

  18. Transport of oxidized multi-walled carbon nanotubes through silica based porous media: influences of aquatic chemistry, surface chemistry, and natural organic matter.

    PubMed

    Yang, Jin; Bitter, Julie L; Smith, Billy A; Fairbrother, D Howard; Ball, William P

    2013-12-17

    This paper provides results from studies of the transport of oxidized multi-walled carbon nanotubes (O-MWCNTs) of varying surface oxygen concentrations under a range of aquatic conditions and through uniform silica glass bead media. In the presence of Na(+), the required ionic strength (IS) for maximum particle attachment efficiency (i.e., the critical deposition concentration, or CDC) increased as the surface oxygen concentration of the O-MWCNTs or pH increased, following qualitative tenets of theories based on electrostatic interactions. In the presence of Ca(2+), CDC values were lower than those with Na(+) present, but were no longer sensitive to surface oxygen content, suggesting that Ca(2+) impacts the interactions between O-MWCNTs and glass beads by mechanisms other than electrostatic alone. The presence of Suwannee River natural organic matter (SRNOM) decreased the attachment efficiency of O-MWCNTs in the presence of either Na(+) or Ca(2+), but with more pronounced effects when Na(+) was present. Nevertheless, low concentrations of SRNOM (<4 mg/L of dissolved organic carbon) were sufficient to mobilize all O-MWCNTs studied at CaCl2 concentrations as high as 10 mM. Overall, this study reveals that NOM content, pH, and cation type show more importance than surface chemistry in affecting O-MWCNTs deposition during transport through silica-based porous media.

  19. Chemical ions affect survival of avian cholera organisms in pondwater

    USGS Publications Warehouse

    Price, J.I.; Yandell, B.S.; Porter, W.P.

    1992-01-01

    Avian cholera (Pasteurella multocida) is a major disease of wild waterfowl, but its epizootiology remains little understood. Consequently, we examined whether chemical ions affected survival of avian cholera organisms in water collected from the Nebraska Rainwater Basin where avian cholera is enzootic. We tested the response of P. multocida to ammonium (NH4), calcium (Ca), magnesium (Mg), nitrate (NO3), and ortho-phosphate (PO4) ions individually and in combination using a fractional factorial design divided into 4 blocks. High concentrations of Ca and Mg, singly or in combination, increased survival of P. multocida organisms (P < 0.001). We developed a survival index to predict whether or not specific ponds could be "problem" or "nonproblem" avian cholera sites based on concentrations of these ions in the water.

  20. Factors that may increase the risk of aquatic organisms to the harmful effects of ultraviolet-B radiation: A management perspective

    SciTech Connect

    Little, E.E.; Fabacher, D.L.

    1995-12-31

    Elevated levels of solar ultraviolet-B (UVB) radiation resulting from stratospheric ozone depletion may cause harmful effects in aquatic organisms. Solar UVB radiation penetrates clear water and can have a direct biological impact on some organisms, causing lesions, infection, and mortality. Numerous evolutionary adaptations and repair mechanisms appear to have evolved in aquatic organisms for coping with solar radiation. The authors found that some species of fish are more susceptible to the harmful effects of solar simulated UVB than other species. Such differences were directly related to the amount of an unidentified dorsal skin component that may function as a natural sunscreen and protect some fish from the harmful effects of UVB. Ozone depletion arising from the destruction of ozone by chlorofluorocarbons is expected to average around 11% annually in mid-northern latitudes through the rest of the century. Since many aquatic organisms appear to exist at their limits of tolerance for solar UVB radiation, environmental changes that result in increased UVB radiation may be directly harmful to sensitive populations. Identification of risk factors and management of aquatic communities exposed to enhanced UVB require not only information about UVB climatology, but also knowledge of the sensitivity and behavioral habits of each species, and an assessment of environmental variables that may increase or mitigate UVB exposure.

  1. Global assessment of arsenic pollution using sperm whales (Physeter macrocephalus) as an emerging aquatic model organism.

    PubMed

    Savery, Laura C; Wise, James T F; Wise, Sandra S; Falank, Carolyne; Gianios, Christy; Thompson, W Douglas; Perkins, Christopher; Zheng, Tongzhang; Zhu, Cairong; Wise, John Pierce

    2014-06-01

    Arsenic is an oceanic pollutant of global concern due to its toxicity, ability to bioaccumulate and continued input into the environment by anthropogenic activities. The sperm whale (Physeter macrocephalus) is an emerging aquatic model for both human disease and ocean health having global distribution and high trophic level. The aim of this study was to establish global and regional baselines of total arsenic concentrations using free-ranging sperm whales. Skin biopsies (n=342) were collected during the voyage of the Odyssey (2000-2005) from 17 regions considering gender and age in males. Arsenic was detectable in 99% of samples with a global mean of 1.9μg/g ww ranging from 0.1 to 15.6μg/g ww. Previous work in toothed whale skin found mean concentrations 3 fold lower with 0.6μg/g ww. A significant gender-related effect was found with males having higher mean arsenic concentrations than females. There was no significant age-related effect between adult and subadult males. Arsenic concentrations in sloughed skin samples were similar to levels in skin biopsies indicating that arsenic excretion can occur by skin sloughing. Regional mean concentrations were highest in the Maldives, Seychelles and Sri Lanka with 3.5, 2.5, and 2.4μg/g ww, respectively, raising concern for arsenic pollution in the Indian Ocean. Literature suggests that arsenic exposure is emitted from natural sources and the heavy use of arsenic-containing pesticides and herbicides in this region. These data suggest that research is needed in determining the extent and source of arsenic pollution in the Indian Ocean.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Do pharmaceuticals reach and affect the aquatic ecosystems in Brazil? A critical review of current studies in a developing country.

    PubMed

    Quadra, Gabrielle Rabelo; Oliveira de Souza, Helena; Costa, Rafaela Dos Santos; Fernandez, Marcos Antonio Dos Santos

    2017-01-01

    Pharmaceutical residues are not completely removed in wastewater treatment plants (WWTPs) becoming contaminants in aquatic ecosystems. Thereby, it is important to investigate their concentrations in the environment and the possible consequences of their occurrence, including for human health. Here, we briefly reviewed the paths of pharmaceuticals to reach the environment, their behavior and fate in the environment, and the possible consequences of their occurrence. Moreover, we synthetized all the studies about the detection of pharmaceuticals in Brazilian water bodies and the available ecotoxicological knowledge on their effects. In this study, when we compare the data found on these compounds worldwide, we observed that Brazilian surface waters present considerable concentrations of 17α-ethinylestradiol, 17β-estradiol, and caffeine. In general, concentrations found in aquatic systems worldwide seems to be low; however, ecotoxicological tests showed that even these low concentrations can cause sublethal effects in biota. The knowledge about the effects of continuous exposure and mixtures is sparse. In summary, new research is urgently required about the effects of these compounds in biota-including long-term exposition and mixture tests-and on specific technologies to remove these compounds in water bodies and WWTPs, besides the introduction of new policies for pharmaceutical use.

  4. PREDICTION OF CHEMICAL RESIDUES IN AQUATIC ORGANISMS FOR A FIELD DISCHARGE SITUATION.

    EPA Science Inventory

    A field study was performed which compared predicted and measured concentrations of chemicals in receiving water organisms from three sampling locations on Five Mile Creek, Birmingham, Al. Two point source discharges, both from coke manufacturing facilities, were included in the ...

  5. DEVELOPMENT OF A PASSIVE, IN SITU, INTEGRATIVE SAMPLER FOR HYDROPHILLIC ORGANIC CONTAMINANTS IN AQUATIC ENVIRONMENTS

    EPA Science Inventory

    Until recently, hydrophobic, bioconcentratable compounds have been the primary focus of most environmental organic contaminant investigations, There is an increasing realization that a holistic hazard assessment of complex environmental contaminant mixtures requires data on the c...

  6. Review: In situ and bioremediation of organic pollutants in aquatic sediments.

    PubMed

    Perelo, Louisa Wessels

    2010-05-15

    Organic pollutants in sediments are a worldwide problem because sediments act as sinks for hydrophobic, recalcitrant and hazardous compounds. Depending on biogeochemical processes these hydrocarbons are involved in adsorption, desorption and transformation processes and can be made available to benthic organisms as well as organisms in the water column through the sediment-water interface. Most of these recalcitrant hydrocarbons are toxic and carcinogenic, they may enter the food-chain and accumulate in biological tissue. Several approaches are being investigated or have been already used to remove organic hydrocarbons from sediments. This paper provides a review on types and sources of organic pollutants as well as their behavior in sediments. It presents the advantages and disadvantages of traditional sediment remediation techniques in use, such as dredging, capping and monitored natural attenuation. Furthermore, it describes new approaches with emphasis on bioremediation, like biostimulation, bioaugmentation and phytoremediation applied to sediments. These new techniques promise to be of lower impact and more cost efficient than traditional management strategies.

  7. Reactivity of Zerovalent Metals in Aquatic Media: Effects of Organic Surface Coatings

    SciTech Connect

    Tratnyek, Paul G.; Salter-Blanc, Alexandra; Nurmi, James; Amonette, James E.; Liu, Juan; Wang, Chong M.; Dohnalkova, Alice; Baer, Donald R.

    2011-09-02

    Granular, reactive zerovalent metals (ZVMs)—especially iron (ZVI)—form the basis for model systems that have been used in fundamental and applied studies of a wide variety of environmental processes. This has resulted in notable advances in many areas, including the kinetics and mechanisms of contaminant reduction reactions, theory of filtration and transport of colloids in porous media, and modeling of complex reactive-transport scenarios. Recent emphasis on nano-sized ZVI has created a new opportunity: to advance the understanding of how coatings of organic polyelectrolytes—like natural organic matter (NOM)—influence the reactivity of environmental surfaces. Depending on many factors, organic coatings can be activating or passivating with respect to redox reactions at particle-solution interfaces. In this study, we show the effects of organic coatings on nZVI vary with a number of factors including: (i) time (i.e., “aging” is evident not only in the structure and composition of the nZVI but also in the interactions between nZVI and NOM) and (ii) the type of organic matter (i.e., suspensions of nZVI are stabilized by NOM and the model polyelectrolyte carboxymethylcellulose (CMC), but NOM stimulates redox reactions involving nZVI while CMC inhibits them).

  8. Toxic contaminant characterization of aquatic organisms in Galveston Bay: A pilot study. Final report

    SciTech Connect

    Brooks, J.M.; Wade, T.L.; Dennicutt, M.C.; Wiesenburg, D.A.; Wilkinson, D.

    1992-06-01

    The study characterizes contamination in edible fish and shellfish from Galveston Bay. The sampling design called for the analysis of trace contaminants in five species from four sites in Galveston Bay. The goal of the sampling program was to collect ten specimens of each target organism that were of legal market size from each collection site. Standard fisheries data were recorded for all collections. The analytical program called for the analyses of 10 individual specimens of the target organisms from each site (200 edible tissue (muscle) samples). Fifty (50) liver samples were composed for analysis from the 120 fishes. The trace contaminants that were measured included heavy metals, polynuclear aromatic hydrocarbons (PAH's), pesticides and PCBs and a GC-MS scan for other EPA organic priority pollutants. In general, trace contaminants were higher in oyster and crab tissues than fish tissue.

  9. Indole signaling and (micro)algal auxins decrease the virulence of Vibrio campbellii, a major pathogen of aquatic organisms.

    PubMed

    Yang, Qian; Pande, Gde Sasmita Julyantoro; Wang, Zheng; Lin, Baochuan; Rubin, Robert A; Vora, Gary J; Defoirdt, Tom

    2017-03-02

    Vibrios belonging to the Harveyi clade are major pathogens of marine vertebrates and invertebrates, causing major losses in wild and cultured organisms. Despite their significant impact, the pathogenicity mechanisms of these bacteria are not yet completely understood. In this study, we investigated the impact of indole signaling on the virulence of Vibrio campbellii. Elevated indole levels significantly decreased motility, biofilm formation, exopolysaccharide production and virulence to crustacean hosts. Indole furthermore inhibited the three-channel quorum sensing system of V. campbellii, a regulatory mechanism that is required for full virulence of the pathogen. Further, indole signaling was found to interact with the stress sigma factor RpoS. Together with our observations that energy-consuming processes (motility and bioluminescence) are downregulated, and microarray-based transcriptomics demonstrating that indole decreases the expression of genes involved in energy and amino acid metabolism, the data suggest that indole is a starvation signal in V. campbellii. Finally, we found that the auxins indole-3-acetic acid and indole-3-acetamide, which are produced by various (micro)algae sharing the aquatic environment with V. campbellii, have a similar effect as observed for indole. Auxins might therefore have a significant impact on the interactions between vibrios, (micro)algae and higher organisms, with major ecological and practical implications. This article is protected by copyright. All rights reserved.

  10. Selected emerging organic contaminants in the Yangtze Estuary, China: a comprehensive treatment of their association with aquatic colloids.

    PubMed

    Yan, Caixia; Yang, Yi; Zhou, Junliang; Nie, Minghua; Liu, Min; Hochella, Michael F

    2015-01-01

    Contaminants that are becoming detected in the environment but are not yet generally regulated or monitored are known collectively as emerging contaminants. In the present study, the occurrence and distribution of 42 emerging organic compounds (EOCs) were investigated in the Yangtze River Estuary and adjacent East China Sea coastal areas. Study compounds were mainly pharmaceuticals, including antibiotics, hormones and sterols, and also included two industrial endocrine disruptors. Samples were analyzed using cross-flow ultrafiltration (CFUF) and ultra-performance liquid chromatograph-tandem mass spectrometry (UPLC-MS/MS). Results revealed that chloramphenicols, sulfonamides and non-steroidal anti-inflammatory drugs were the dominant compounds in filtered samples with relatively high concentrations and detection frequencies. EOC levels varied with location, with the highest concentrations being observed around rivers discharging into the estuary, and near sewage outfalls. Colloids that were separated by CFUF tended to be a sink for EOCs with up to 60% being colloid-associated in the water phase. In addition, colloidal properties, including hydrodynamic size, zeta-potential and organic carbon composition, were found to be the main factors controlling the association of EOCs with aquatic colloids. Moreover, these colloidal properties were all significantly related to salinity, indicating the critical role played by increasing salinity in EOCs-colloids interaction in an estuarine system.

  11. Physicochemical properties and ecotoxicological effects of yttrium oxide nanoparticles in aquatic media: Role of low molecular weight natural organic acids.

    PubMed

    Zhang, Fan; Wang, Zhuang; Wang, Se; Fang, Hao; Chen, Mindong; Xu, Defu; Tang, Lili; Wang, Degao

    2016-05-01

    Understanding how engineered nanoparticles (ENPs) interact with natural organic acids is important to ecological risk assessment of ENPs, but this interaction remains poorly studied. Here, we investigate the dispersion stability, ion release, and toxicity of yttrium oxide nanoparticles (nY2O3) suspensions after exposure to two low molecular weight natural organic acids (LOAs), namely benzoic acid and gallic acid. We find that in the presence of LOAs the nY2O3 suspensions become more stable with surface zeta potential more positive or negative, accompanied by small agglomerated size. LOA interaction with nY2O3 is shown to promote the release of dissolved yttrium from the nanoparticles, depending on the concentrations of LOAs. Toxic effects of the nY2O3 suspensions incubated with LOAs on Scenedesmus obliquus as a function of their mixture levels show three types of signs: stimulation, inhibition, and alleviation. The mechanism of the effects of LOAs on the nY2O3 toxicity may be mainly associated with the degree of agglomeration, particle-induced oxidative stress, and dissolved yttrium. Our results stressed the importance of LOA impacts on the fate and toxicity of ENPs in the aquatic environment.

  12. Effect of Temperature, Grain Size and Organic Content on Persistence of Fecal Indicator Bacteria in Aquatic Sediments

    NASA Astrophysics Data System (ADS)

    Martinez, N. T.; Juhl, A. R.; O'Mullan, G. D.

    2011-12-01

    Pathogenic bacteria from poorly treated sewage present a health threat in recreational waters. Sewage derived bacteria can attach to particles and sink to the bottom, where they may persist longer than in the water column. If sewage derived bacteria persist, contaminated sediments may function as a reservoir for indicator bacteria and pathogens that can be resuspended, recontaminating the water column. We quantified the persistence of the fecal indicator bacteria (FIB), Escherichia coli and Enterococcus sp., in aquatic sediment microcosms in relation to sediment organic content, grain size and temperature. Surface sediment used for microcosms came from 5 near shore Hudson River estuary sites with different grain size distributions and organic content. Sediments from each location were divided into three separate containers that were then incubated in darkness at 18°, 25° and 30° C for several weeks. Subsamples were collected from each microcosm approximately weekly to track the decay of the FIB as a function of time. Duration required for 90% decay in different microcosms ranged from 6.7 to 63 days for E. coli and 5.1 to 60 days for Enterococcus sp., longer than has been typically observed in the water column. Our measurements of E. coli persistence were also longer than described in previous work. We found that E. coli persistence was strongly related to temperature with faster decay at higher temperatures. In contrast, Enterococcus sp. persistence was weakly related to temperature but was strongly related to sediment organic content and grain size distribution with decay rate increasing in sediments of low organic content and coarser grain size. Quantification of FIB persistence in sediment reservoirs can be used in water quality and public health predictions. The contrasting responses of E. coli and Enterococcus sp. persistence to sediment characteristics implies different suitability as indicators depending on environmental conditions.

  13. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., planktonic organisms, and the plants and animals on which they feed and depend upon for their needs. All... competitive species of plant or animal at the expense of the desired resident species. Suspended particulates... reproduction and growth and development due primarily to their limited mobility. They can be rendered unfit...

  14. Development and validation of an in-house quantitative analysis method for cylindrospermopsin using hydrophilic interaction liquid chromatography-tandem mass spectrometry: Quantification demonstrated in 4 aquatic organisms.

    PubMed

    Esterhuizen-Londt, Maranda; Kühn, Sandra; Pflugmacher, Stephan

    2015-12-01

    The cyanobacterial toxin cylindrospermopsin (CYN) is of great concern in aquatic environments because of its incidence, multiple toxicity endpoints, and, therefore, the severity of health implications. It may bioaccumulate in aquatic food webs, resulting in high exposure concentrations to higher-order trophic levels, particularly humans. Because of accumulation at primary levels resulting from exposure to trace amounts of toxin, a sensitive analytical technique with proven aquatic applications is required. In the present study, a hydrophilic interaction liquid chromatographic-tandem mass spectrometric method with a lower limit of detection of 200 fg on column (signal-to-noise ratio = 3, n = 9) and a lower limit of quantification of 1 pg on column (signal-to-noise ratio = 11, n = 9) with demonstrated application in 4 aquatic organisms is described. The analytical method was optimized and validated with a linear range (r(2) = 0.999) from 0.1 ng mL(-1) to 100 ng mL(-1) CYN. Mean recovery of the extraction method was 98 ± 2%. Application of the method was demonstrated by quantifying CYN uptake in Scenedesmus subspicatus (green algae), Egeria densa (Brazilian waterweed), Daphnia magna (water flea), and Lumbriculus variegatus (blackworm) after 24 h of static exposure to 50 μg L(-1) CYN. Uptake ranged from 0.05% to 0.11% of the nominal CYN exposure amount. This constitutes a sensitive and reproducible method for extraction and quantification of unconjugated CYN with demonstrated application in 4 aquatic organisms, which can be used in further aquatic toxicological investigations.

  15. Aquatic photolysis: photolytic redox reactions between goethite and adsorbed organic acids in aqueous solutions

    USGS Publications Warehouse

    Goldberg, M.C.; Cunningham, K.M.; Weiner, Eugene R.

    1993-01-01

    Photolysis of mono and di-carboxylic acids that are adsorbed onto the surface of the iron oxyhydroxide (goethite) results in an oxidation of the organic material and a reduction from Fe(III) to Fe(II) in the iron complex. There is a subsequent release of Fe2+ ions into solution. At constant light flux and constant solution light absorption, the factors responsible for the degree of photolytic reaction include: the number of lattice sites that are bonded by the organic acid; the rate of acid readsorption to the surface during photolysis; the conformation and structure of the organic acid; the degree of oxidation of the organic acid; the presence or absence of an ??-hydroxy group on the acid, the number of carbons in the di-acid chain and the conformation of the di-acid. The ability to liberate Fe(III) at pH 6.5 from the geothite lattice is described by the lyotropic series: tartrate>citrate> oxalate > glycolate > maleate > succinate > formate > fumarate > malonate > glutarate > benzoate = butanoate = control. Although a larger amount of iron is liberated, the series is almost the same at pH 5.5 except that oxalate > citrate and succinate > maleate. A set of rate equations are given that describe the release of iron from the goethite lattice. It was observed that the pH of the solution increases during photolysis if the solutions are not buffered. There is evidence to suggest the primary mechanism for all these reactions is an electron transfer from the organic ligand to the Fe(III) in the complex. Of all the iron-oxyhydroxide materials, crystalline goethite is the least soluble in water; yet, this study indicates that in an aqueous suspension, iron can be liberated from the goethite lattice. Further, it has been shown that photolysis can occur in a multiphase system at the sediment- water interface which results in an oxidation of the organic species and release of Fe2+ to solution where it becomes available for further reaction. ?? 1993.

  16. National standards and guidelines for pesticides in water, sediment, and aquatic organisms: application to water-quality assessments.

    PubMed

    Nowell, L H; Resek, E A

    1994-01-01

    National standards and guidelines for pesticides can be useful tools in water-quality assessment for evaluating potential human health or ecological effects of measured pesticide residues in water, bed sediment, or aquatic organisms. However, valid use of a given standard or guideline requires an understanding of its technical basis and underlying assumptions. Each type of standard or guideline is specific for one sampling medium (water, bed sediment, and fish and shellfish tissue) and is aimed at protection of one or more beneficial uses of the hydrologic system (drinking water, fish and shellfish consumption, aquatic organisms, and wildlife). These characteristics can be used to identify which standards and guidelines are appropriate for comparison with measured pesticide concentrations in environmental samples from a given hydrologic system. A review of standards and guidelines can be restricted to the applicable sampling medium. Then, the beneficial uses of the hydrologic system need to be identified and the measured pesticide concentrations compared with standards and guidelines for all beneficial uses that apply to that system. Several key factors that must be considered when applying this general process to water-quality assessment are summarized below. Two precautions need to be considered regarding sampling media: 1. Standards and guidelines for water distinguish between finished drinking water (potable water, often treated) and ambient surface water. If standards and guidelines for drinking water (EPA primary drinking-water regulations and drinking-water health advisories) are applied to measured pesticide concentrations in ambient water samples, the effects of water treatment (such as filtration) need to be considered. 2. Standards and guidelines for fish and shellfish tissue distinguish between edible fish and shellfish tissue and whole fish tissue. Comparison of pesticide concentrations in whole fish tissue with standards or guidelines for edible fish

  17. Impacts of low-molecular-weight organic acids on aquatic behavior of graphene nanoplatelets and their induced algal toxicity and antioxidant capacity.

    PubMed

    Wang, Zhuang; Gao, Yucheng; Wang, Se; Fang, Hao; Xu, Defu; Zhang, Fan

    2016-06-01

    Knowledge of the interaction between graphene-based materials and low-molecular-weight organic acids (LOAs) is essential to understand fate and effects of graphene-based materials in the aquatic environment, but this interaction remains poorly elucidated. In this study, the effects of LOAs on the physicochemical properties of graphene nanoplatelets (GNPs) in an aqueous medium and on the GNP toxicity to algae were studied. The unicellular green alga Scenedesmus obliquus was exposed to GNP suspensions in the presence of benzoic acid or gallic acid at various concentrations. The GNPs had smaller hydrodynamic sizes and the GNP suspensions were more stable and had higher or lower surface zeta potentials in the presence of LOAs than when LOAs were not present. The toxic effects in S. obliquus cultures incubated with GNP suspensions containing LOAs were related to the LOA concentration, and the presence of LOAs caused three effects: stimulation, alleviation, and synergistic inhibition. The intensities of the effects mainly correlated with the LOA concentration, the extent of agglomeration, and particle-induced oxidative stress. The results indicate that the environmental fates and toxicities of GNPs are strongly affected by the binding of GNPs to LOAs.

  18. Tetrodotoxin – Distribution and Accumulation in Aquatic Organisms, and Cases of Human Intoxication

    PubMed Central

    Noguchi, Tamao; Arakawa, Osamu

    2008-01-01

    Many pufferfish of the family Tetraodontidae possess a potent neurotoxin, tetrodotoxin (TTX). In marine pufferfish species, toxicity is generally high in the liver and ovary, whereas in brackish water and freshwater species, toxicity is higher in the skin. In 1964, the toxin of the California newt was identified as TTX as well, and since then TTX has been detected in a variety of other organisms. TTX is produced primarily by marine bacteria, and pufferfish accumulate TTX via the food chain that begins with these bacteria. Consequently, pufferfish become non-toxic when they are fed TTX-free diets in an environment in which the invasion of TTX-bearing organisms is completely shut off. Although some researchers claim that the TTX of amphibians is endogenous, we believe that it also has an exogenous origin, i.e., from organisms consumed as food. TTX-bearing animals are equipped with a high tolerance to TTX, and thus retain or accumulate TTX possibly as a biologic defense substance. There have been many cases of human intoxication due to the ingestion of TTX-bearing pufferfish, mainly in Japan, China, and Taiwan, and several victims have died. Several cases of TTX intoxication due to the ingestion of small gastropods, including some lethal cases, were recently reported in China and Taiwan, revealing a serious public health issue. PMID:18728726

  19. Science: Aquatic Toxicology Matures, Gains Importance.

    ERIC Educational Resources Information Center

    Dagani, Ron

    1980-01-01

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

  20. The Vinylguaiacol/Indole or VGI ("Veggie") Ratio: A Novel Molecular Parameter to Evaluate the Relative Contributions of Terrestrial and Aquatic Organic Matter to Sediments

    NASA Astrophysics Data System (ADS)

    Kruge, M. A.; Olsen, K. K.; Slusarczyk, J.; Gomez, E.

    2010-12-01

    The organic matter (OM) fraction of estuarine sediments is often distinctive and thus diagnostically useful in determinations of sedimentary provenance. Among the most fundamental distinctions to be made is that between terrestrial and aquatic OM. To supplement the parameters commonly used for this purpose (e.g., C/N and stable isotope ratios), we proposed the Vinylguaiacol/Indole or VGI ("Veggie") ratio, defined as [vinylguaiacol / (indole + vinylguaiacol)] using data produced by analytical pyrolysis-gas chromatography/mass spectrometry of dried, homogenized sediment samples. The ratio employs the peak areas of these two compounds on the mass chromatograms of their molecular ions (m/z 150 and 117). Major pyrolysis products of terrestrial plant lignin include a variety of methoxyphenols, notably 4-vinylguaiacol. In contrast, aquatic algae and bacteria characteristically produce distinctive organonitrogen compounds upon pyrolysis, particularly indole, derived from the amino acid tryptophan. The end member VGI ratio value of 1.00 is obtained for reference land plant matter, including the marsh plants Phragmites and Spartina, as well as maple and pine wood. The end member value of 0.00 is obtained for cultured microbes, including Escherichia coli and the cyanobacterium Anacystis. Vinylguaiacol and indole are commonly detected in Recent sediment pyrolyzates. We hypothesized that their relative quantities therein should be proportional to the relative contributions of land plant and microbial OM, respectively. Samples taken from Spartina peat marshes at the mouths of major rivers (Housatonic and Connecticut) entering Long Island Sound, wetlands behind the barrier island at Cape May (NJ), and a Phragmites-dominated tidal marsh along the Hackensack River (NJ) have high (> 0.8) VGI ratio values. Sediments collected within the Newark Bay (NJ) estuary from the lower Passaic and Hackensack Rivers and the Arthur Kill show mixed terrestrial and aquatic OM signatures (VGI from 0

  1. Initial pH of medium affects organic acids production but do not affect phosphate solubilization

    PubMed Central

    Marra, Leandro M.; de Oliveira-Longatti, Silvia M.; Soares, Cláudio R.F.S.; de Lima, José M.; Olivares, Fabio L.; Moreira, Fatima M.S.

    2015-01-01

    The pH of the culture medium directly influences the growth of microorganisms and the chemical processes that they perform. The aim of this study was to assess the influence of the initial pH of the culture medium on the production of 11 low-molecular-weight organic acids and on the solubilization of calcium phosphate by bacteria in growth medium (NBRIP). The following strains isolated from cowpea nodules were studied: UFLA03-08 (Rhizobium tropici), UFLA03-09 (Acinetobacter sp.), UFLA03-10 (Paenibacillus kribbensis), UFLA03-106 (Paenibacillus kribbensis) and UFLA03-116 (Paenibacillus sp.). The strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 solubilized Ca3(PO4)2 in liquid medium regardless of the initial pH, although without a significant difference between the treatments. The production of organic acids by these strains was assessed for all of the initial pH values investigated, and differences between the treatments were observed. Strains UFLA03-09 and UFLA03-10 produced the same acids at different initial pH values in the culture medium. There was no correlation between phosphorus solubilized from Ca3(PO4)2 in NBRIP liquid medium and the concentration of total organic acids at the different initial pH values. Therefore, the initial pH of the culture medium influences the production of organic acids by the strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 but it does not affect calcium phosphate solubilization. PMID:26273251

  2. Reconciling the role of organic matter pathways in aquatic food webs by measuring multiple tracers in individuals.

    PubMed

    Jardine, Timothy D; Woods, Ryan; Marshall, Jonathan; Fawcetr, James; Lobegeiger, Jaye; Valdez, Dominic; Kainz, Martin J

    2015-12-01

    Few studies measure multiple ecological tracers in individual organisms, thus limiting our ability to differentiate among organic matter source pathways and understand consequences of dietary variation and the use of external subsidies in complex food webs. We combined two tracers, stable isotope (SI) ratios and fatty acids (FA), to investigate linkages among ecological compartments (water column, benthos, riparian zone) in food webs in waterholes of a dryland river network, the Border Rivers in southwestern Queensland, Australia. Comprehensive analyses of sources (plankton, periphyton, leaf litter, riparian grasses) and animals (benthic insects, mollusks, large crustaceans, fishes) for SI and FA showed that all three zones contribute to animal biomass, depending on species and life stage. Large fishes derived a subsidy from the riparian/floodplain zone, likely through the consumption of terrestrial and semi-aquatic insects and prawns that fed on detritivorous insects. Importantly, post-larval bony bream (Nematalosa erebi) and golden perch (Macquaria ambigua) were tightly connected to the water column, as evidenced by 13C-depleted, 15N-enriched isotope ratios and a high content of plankton-derived polyunsaturated fatty acids (eicosapentaenoic acid [EPA; 20:53] and docosahexaenoic acid [DHA; 22:6003]). These observations were consistent with expectations from nutritional requirements of fish early life stages and habitat changes associated with maturity. These results highlight the importance of high-quality foods during early development of fishes, and show that attempting to attribute food-web production to a single source pathway overlooks important but often subtle subsidies that maintain viable populations. A complete understanding of food-web dynamics must consider both quantity and quality of different available organic matter sources. This understanding can be achieved with a combined SI and FA approach, but more controlled dietary studies are needed to

  3. Estimation of the Risks of Collision or Strike to Freshwater Aquatic Organisms Resulting from Operation of Instream Hydrokinetic Turbines

    SciTech Connect

    Schweizer, Peter E; Cada, Glenn F; Bevelhimer, Mark S

    2010-05-01

    Hydrokinetic energy technologies have been proposed as renewable, environmentally preferable alternatives to fossil fuels for generation of electricity. Hydrokinetic technologies harness the energy of water in motion, either from waves, tides or from river currents. For energy capture from free-flowing rivers, arrays of rotating devices are most commonly proposed. The placement of hydrokinetic devices in large rivers is expected to increase the underwater structural complexity of river landscapes. Moore and Gregory (1988) found that structural complexity increased local fish populations because fish and other aquatic biota are attracted to structural complexity that provides microhabitats with steep flow velocity gradients (Liao 2007). However, hydrokinetic devices have mechanical parts, blades, wings or bars that move through the water column, posing a potential strike or collision risk to fish and other aquatic biota. Furthermore, in a setting with arrays of hydrokinetic turbines the cumulative effects of multiple encounters may increase the risk of strike. Submerged structures associated with a hydrokinetic (HK) project present a collision risk to aquatic organisms and diving birds (Cada et al. 2007). Collision is physical contact between a device or its pressure field and an organism that may result in an injury to that organism (Wilson et al. 2007). Collisions can occur between animals and fixed submerged structures, mooring equipment, horizontal or vertical axis turbine rotors, and structures that, by their individual design or in combination, may form traps. This report defines strike as a special case of collision where a moving part, such as a rotor blade of a HK turbine intercepts the path of an organism of interest, resulting in physical contact with the organism. The severity of a strike incidence may range from minor physical contact with no adverse effects to the organism to severe strike resulting in injury or death of the organism. Harmful effects

  4. Effect of AL2O3 and TiO2 nanoparticles on aquatic organisms

    NASA Astrophysics Data System (ADS)

    Gosteva, I.; Morgalev, Yu; Morgaleva, T.; Morgalev, S.

    2015-11-01

    Environmental toxicity of aqueous disperse systems of nanoparticles of binary compounds of titanium dioxides (with particle size Δ50=5 nm, Δ50=50 nm, Δ50=90 nm), aluminum oxide alpha-forms (Δ50=7 nm and Δ50=70 nm) and macro forms (TiO2 Δ50=350 nm, Al2O3 A50=4000 nm) were studied using biological testing methods. The bioassay was performed using a set of test organisms representing the major trophic levels. We found the dependence of the toxic effect concentration degree of nTiO2 and nAl2O3 on the fluorescence of the bacterial biosensor "Ekolyum", the chemotactic response of ciliates Paramecium caudatum, the growth of unicellular algae Chlorella vulgaris Beijer and mortality of entomostracans Daphnia magna Straus. We revealed the selective dependence of nTiO2 and nAl2O3 toxicity on the size, concentration and chemical nature of nanoparticles. The minimal concentration causing an organism's response on nTiO2 and nAl2O3 effect depends on the type of the test- organism and the test reaction under study. We specified L(E)C50 and acute toxicity categories for all the studied nanoparticles. We determined that nTiO2 (Δ50=5 nm) belong to the category «Acute toxicity 1», nTiO2 (A50=90 nm) and nAl2O3 (Δ50=70 nm) - to the category «Acute toxicity 2», nAl2O3 (Δ50=7 nm) - to the category «Acute toxicity 3». No acute toxicity was registered for nTiO2 (Δ50=50 nm) and macro form TiO2.

  5. Explanations for the acclimation period preceding the mineralization of organic chemicals in aquatic environments.

    PubMed Central

    Wiggins, B A; Jones, S H; Alexander, M

    1987-01-01

    A study was conducted of possible reasons for acclimation of microbial communities to the mineralization of organic compounds in lake water and sewage. The acclimation period for the mineralization of 2 ng of p-nitrophenol (PNP) or 2,4-dichlorophenoxyacetic acid per ml of sewage was eliminated when the sewage was incubated for 9 or 16 days, respectively, with no added substrate. The acclimation period for the mineralization of 2 ng but not 200 ng or 2 micrograms of PNP per ml was eliminated when the compound was added to lake water that had been first incubated in the laboratory. Mineralization of PNP by Flavobacterium sp. was detected within 7 h at concentrations of 20 ng/ml to 2 micrograms/ml but only after 25 h at 2 ng/ml. PNP-utilizing organisms began to multiply logarithmically after 1 day in lake water amended with 2 micrograms of PNP per ml, but substrate disappearance was only detected at 8 days, at which time the numbers were approaching 10(5) cells per ml. The addition of inorganic nutrients reduced the length of the acclimation period from 6 to 3 days in sewage and from 6 days to 1 day in lake water. The prior degradation of natural organic materials in the sewage and lake water had no effect on the acclimation period for the mineralization of PNP, and naturally occurring inhibitors that might delay the mineralization were not present. The length of the acclimation phase for the mineralization of 2 ng of PNP per ml was shortened when the protozoa in sewage were suppressed by eucaryotic inhibitors, but it was unaffected or increased if the inhibitors were added to lake water.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3579282

  6. Evaluation of the effect of water type on the toxicity of nitrate to aquatic organisms.

    PubMed

    Baker, Josh A; Gilron, Guy; Chalmers, Ben A; Elphick, James R

    2017-02-01

    A suite of acute and chronic toxicity tests were conducted to evaluate the sensitivity of freshwater organisms to nitrate (as sodium nitrate). Acute exposures with rainbow trout (Onchorhynchus mykiss) and amphipods (Hyalella azteca), as well as chronic exposures with H. azteca (14-d survival and growth), midges (Chironomus dilutus; 10-d survival and growth), daphnids (Ceriodaphnia dubia; 7-d survival and reproduction), and fathead minnows (Pimephales promelas; 7-d survival and growth) were used to determine sublethal and lethal effect concentrations. Modification of nitrate toxicity was investigated across a range of ionic strengths, created through the use of very soft water, and standard preparations of synthetic soft, moderately-hard and hard dilution waters. The most sensitive species tested were C. dubia and H. azteca, in soft water, with reproduction and growth IC25 values of 13.8 and 12.2 mg/L NO3-N, respectively. All of the organisms exposed to nitrate demonstrated significantly reduced effects with increasing ionic strength associated with changes in water type. Possible mechanisms responsible for the modifying effect of increasing major ion concentrations on nitrate toxicity are discussed.

  7. Passive Sampling in Regulatory Chemical Monitoring of Nonpolar Organic Compounds in the Aquatic Environment.

    PubMed

    Booij, Kees; Robinson, Craig D; Burgess, Robert M; Mayer, Philipp; Roberts, Cindy A; Ahrens, Lutz; Allan, Ian J; Brant, Jan; Jones, Lisa; Kraus, Uta R; Larsen, Martin M; Lepom, Peter; Petersen, Jördis; Pröfrock, Daniel; Roose, Patrick; Schäfer, Sabine; Smedes, Foppe; Tixier, Céline; Vorkamp, Katrin; Whitehouse, Paul

    2016-01-05

    We reviewed compliance monitoring requirements in the European Union, the United States, and the Oslo-Paris Convention for the protection of the marine environment of the North-East Atlantic, and evaluated if these are met by passive sampling methods for nonpolar compounds. The strengths and shortcomings of passive sampling are assessed for water, sediments, and biota. Passive water sampling is a suitable technique for measuring concentrations of freely dissolved compounds. This method yields results that are incompatible with the EU's quality standard definition in terms of total concentrations in water, but this definition has little scientific basis. Insufficient quality control is a present weakness of passive sampling in water. Laboratory performance studies and the development of standardized methods are needed to improve data quality and to encourage the use of passive sampling by commercial laboratories and monitoring agencies. Successful prediction of bioaccumulation based on passive sampling is well documented for organisms at the lower trophic levels, but requires more research for higher levels. Despite the existence of several knowledge gaps, passive sampling presently is the best available technology for chemical monitoring of nonpolar organic compounds. Key issues to be addressed by scientists and environmental managers are outlined.

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

    USGS Publications Warehouse

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

    1999-01-01

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

  9. Body composition in aquatic organisms — A global data bank of relationships between mass, elemental composition and energy content

    NASA Astrophysics Data System (ADS)

    Brey, Thomas; Müller-Wiegmann, Corinna; Zittier, Zora M. C.; Hagen, Wilhelm

    2010-10-01

    We introduce a global data bank on body composition of aquatic organisms that is available at http://www.thomas-brey.de/science/virtualhandbook. It covers ratios between body mass (wet, dry, ash free dry mass), body composition (protein, lipid, carbohydrate), macro-elements (C, N, P) and energy content (J). Sofar, data for 3158 different taxa (animals, plants, bacteria) were collected from 725 different sources. The principal purpose of the data bank is mining for conversion factors, as necessary in ecological studies that require a common energetic currency. The data bank can be used to explore general ecological principles, too: among all animals, carnivorous swimmers have the highest energy density, presumably an across-taxon selection for propulsion power and handling force. Plants and animals do not only differ in their C/N and C/P ratios, but these ratios change with temperature in opposite directions. In plants, C/N and C/P increase with temperature, most likely a response to the higher levels of N and P in polar waters. In animals C/N and C/P decrease with temperature, an indicator for selection towards lower activity and larger lipid stores in polar animals.

  10. Lake secondary production fueled by rapid transfer of low molecular weight organic carbon from terrestrial sources to aquatic consumers.

    PubMed

    Berggren, M; Ström, L; Laudon, H; Karlsson, J; Jonsson, A; Giesler, R; Bergström, A-K; Jansson, M

    2010-07-01

    Carbon of terrestrial origin often makes up a significant share of consumer biomass in unproductive lake ecosystems. However, the mechanisms for terrestrial support of lake secondary production are largely unclear. By using a modelling approach, we show that terrestrial export of dissolved labile low molecular weight carbon (LMWC) compounds supported 80% (34-95%), 54% (19-90%) and 23% (7-45%) of the secondary production by bacteria, protozoa and metazoa, respectively, in a 7-km(2) boreal lake (conservative to liberal estimates in brackets). Bacterial growth on LMWC was of similar magnitude as that of primary production (PP), and grazing on bacteria effectively channelled the LMWC carbon to higher trophic levels. We suggest that rapid turnover of forest LMWC pools enables continuous export of fresh photosynthates and other labile metabolites to aquatic systems, and that substantial transfer of LMWC from terrestrial sources to lake consumers can occur within a few days. Sequestration of LMWC of terrestrial origin, thus, helps explain high shares of terrestrial carbon in lake organisms and implies that lake food webs can be closely dependent on recent terrestrial PP.

  11. Predicting Polycyclic Aromatic Hydrocarbon Concentrations in Resident Aquatic Organisms Using Passive Samplers and Partial Least-Squares Calibration

    PubMed Central

    2015-01-01

    The current work sought to develop predictive models between time-weighted average polycyclic aromatic hydrocarbon (PAH) concentrations in the freely dissolved phase and those present in resident aquatic organisms. We deployed semipermeable membrane passive sampling devices (SPMDs) and collected resident crayfish (Pacifastacus leniusculus) at nine locations within and outside of the Portland Harbor Superfund Mega-site in Portland, OR. Study results show that crayfish and aqueous phase samples collected within the Mega-site had PAH profiles enriched in high molecular weight PAHs and that freely dissolved PAH profiles tended to be more populated by low molecular weight PAHs compared to crayfish tissues. Results also show that of several modeling approaches, a two-factor partial least-squares (PLS) calibration model using detection limit substitution provided the best predictive power for estimating PAH concentrations in crayfish, where the model explained ≥72% of the variation in the data set and provided predictions within ∼3× of measured values. Importantly, PLS calibration provided a means to estimate PAH concentrations in tissues when concentrations were below detection in the freely dissolved phase. The impact of measurements below detection limits is discussed. PMID:24800862

  12. Spatial and temporal patterns of endocrine active chemicals in small streams indicate differential exposure to aquatic organisms

    USGS Publications Warehouse

    Lee, K.E.; Barber, L.B.; Schoenfuss, H.L.

    2014-01-01

    Alkylphenolic chemicals (APCs) and hormones were measured six times from February through October 2007 in three Minnesota streams receiving wastewater to identify spatial and temporal patterns in concentrations and in estrogen equivalency. Fish were collected once during the study to evaluate endpoints indicative of endocrine disruption. The most commonly detected APCs were 4-tert-octylphenol and 4-nonylphenol and the most commonly detected hormones were estrone and androstenedione. Chemical concentrations were greatest for nonylphenol ethoxycarboxylates (NPECs) (5,000-140,000 ng/l), followed by 4-nonlylphenol and 4-nonylphenolethoxylates (50-880 ng/l), 4-tert-octylphenol and 4-tert-octylphenolethoxylates with concentrations as great as 130 ng/l, and hormones (0.1-54 ng/l). Patterns in chemicals and estrogen equivalency indicated that wastewater effluent is a pathway of APCs and hormones to downstream locations in this study. However, upstream contributions can be equally or more important indicating alternative sources. This study indicates that aquatic organisms experience both spatially and temporally variable exposures in the number of compounds, total concentrations, and estrogenicity. This variability was evident in fish collected from the three rivers as no clear upstream to downstream pattern of endocrine disruption endpoints emerged.

  13. Distribution of perfluoroalkyl substances (PFASs) with isomer analysis among the tissues of aquatic organisms in Taihu Lake, China.

    PubMed

    Fang, Shuhong; Zhao, Shuyan; Zhang, Yifeng; Zhong, Wenjue; Zhu, Lingyan

    2014-10-01

    The distribution of perfluoroalkyl substances (PFASs) and the isomers of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) was investigated among various tissues (including muscle, gill, kidney, liver) and eggs, in aquatic organisms in Taihu Lake, China. Highest concentration of ΣPFASs was mostly found in liver (278-685 ng/g ww) and eggs (66.0-467 ng/g ww) while the lowest was in muscle (40.6-165 ng/g ww). n-PFOS was the predominant PFOS isomer in most of the tissues with a proportion of 46.3-96.5%. Ratios of PFAS concentrations in eggs to those in liver (E/L) increased positively with the protein-water partition coefficient. The E/L of PFOS isomers descended in the order: linear > monomethyl > diperfluoromethyl isomers. The liver/muscle and kidney/muscle ratios of n-PFOS were higher than branched isomers, suggesting that n-PFOS has higher binding affinity with hepatic proteins or branched isomers are preferentially excreted though liver and kidney.

  14. Efficacy of Two Larvasonic™ Units Against Culex Larvae and Effects on Common Aquatic Nontarget Organisms in Harris County, Texas.

    PubMed

    Fredregill, Chris L; Motl, Greg C; Dennett, James A; Bueno, Rudy; Debboun, Mustapha

    2015-12-01

    The Larvasonic™ Field Arm Mobile Wetlands Unit and SD-Mini were tested for efficacy against Culex larvae, and effects on aquatic nontarget organisms (NTO). The Field Arm provided 84.61% to 100% control of caged Culex larvae out to 0.91-m distance in shallow ditches and 60.45% control of Culex larvae at 0.61-m without any effects to caged NTO. Slow ditch treatment achieved 77.35% control compared to fast treatment (20.42%), whereas 77.65% control was obtained along edges of a neglected swimming pool, compared to near the middle (23.97%). In bucket tests, the SD-Mini provided >97% control of Culex and 85.35% reduction of immature giant water bugs, which decreased slightly (83.45%) over the monitoring period, which was not significantly different from cannibalistic damselflies (62.80%), with reduction of both being significantly higher than other NTO tested. There was a small (0.37%) reduction of dragonflies (naiads), due to cannibalism. Both Larvasonic units could effectively augment conventional larvicide operations in smaller areas without causing resistance within mosquito populations or harming NTO when used properly.

  15. A Review of Phage Therapy against Bacterial Pathogens of Aquatic and Terrestrial Organisms

    PubMed Central

    Doss, Janis; Culbertson, Kayla; Hahn, Delilah; Camacho, Joanna; Barekzi, Nazir

    2017-01-01

    Since the discovery of bacteriophage in the early 1900s, there have been numerous attempts to exploit their innate ability to kill bacteria. The purpose of this report is to review current findings and new developments in phage therapy with an emphasis on bacterial diseases of marine organisms, humans, and plants. The body of evidence includes data from studies investigating bacteriophage in marine and land environments as modern antimicrobial agents against harmful bacteria. The goal of this paper is to present an overview of the topic of phage therapy, the use of phage-derived protein therapy, and the hosts that bacteriophage are currently being used against, with an emphasis on the uses of bacteriophage against marine, human, animal and plant pathogens. PMID:28335451

  16. Strategies for Transferring Mixtures of Organic Contaminants from Aquatic Environments into Bioassays.

    PubMed

    Jahnke, Annika; Mayer, Philipp; Schäfer, Sabine; Witt, Gesine; Haase, Nora; Escher, Beate I

    2016-06-07

    Mixtures of organic contaminants are ubiquitous in the environment. Depending on their persistence and physicochemical properties, individual chemicals that make up the mixture partition and distribute within the environment and might then jointly elicit toxicological effects. For the assessment and monitoring of such mixtures, a variety of cell-based in vitro and low-complexity in vivo bioassays based on algae, daphnids or fish embryos are available. A very important and sometimes unrecognized challenge is how to combine sampling, extraction and dosing to transfer the mixtures from the environment into bioassays, while conserving (or re-establishing) their chemical composition at adjustable levels for concentration-effect assessment. This article outlines various strategies for quantifiable transfer from environmental samples including water, sediment, and biota into bioassays using total extraction or polymer-based passive sampling combined with either solvent spiking or passive dosing.

  17. Fractionation of aquatic natural organic matter upon sorption to goethite and kaolinite

    USGS Publications Warehouse

    Meier, M.; Namjesnik-Dejanovic, K.; Maurice, P.A.; Chin, Y.-P.; Aiken, G.R.

    1999-01-01

    Natural organic matter (NOM) consists of a complex mixture of organic molecules; previous studies have suggested that preferential sorption of higher molecular weight, more hydrophobic, and more aromatic components may lead to fractionation of the NOM pool upon passage through porous media. Our work expands upon previous studies by quantifying the change in solution-phase weight average molecular weight (M(w)) upon sorption of bulk (rather than isolated) surface water NOM from the Suwannee River (SR) and the Great Dismal Swamp (GDS) to goethite and kaolinite at different sorption densities and at pH 4, 22??C. High pressure size exclusion chromatography (HPSEC) was used to quantify changes in M(w) upon sorption, and molar absorptivities at ?? = 280 nm were used to approximate changes in solution NOM aromaticity. Two SR water samples were used, with M(w) = 2320 and 2200 Da; a single GDS sample was used, with M(w) = 1890 Da. The SR NOM was slightly more hydrophobic and aromatic. These differences were reflected in greater sorption of SR NOM than GDS NOM. Both surface water NOMs showed a much greater affinity for goethite than for kaolinite. HPSEC analysis of the NOM remaining in solution after 24 h reaction time with geothite revealed that the largest changes in solution phase M(w)s (decreases by 900-1700 Da) occurred at relatively low equilibrium sorbate concentrations (approximately 5-20 mg C 1-1); the decrease in solution M(w) suggested that reactive surface sites were occupied disproportionately by large and intermediate size NOM moieties. At higher equilibrium NOM concentrations (>20 mg C 1-1), as percent adsorption decreased, M(w) in solution was similar to original samples. A smaller decrease in solution NOM M(w) (300-500 Da at 10-20 mg C 1-1 ~ 100 Da at > 20 mg) also occurred upon sorption to kaolinite. Overall, our results showed that factors (as related to NOM composition, clay mineral surface properties, and position along the sorption isotherm) which

  18. The Potential Impacts of OTEC Intakes on Aquatic Organisms at an OTEC Site under Development on Kauai, HI

    SciTech Connect

    Oney, Stephen K.; Hogan, Timothy; Steinbeck, John

    2013-08-31

    Ocean thermal energy conversion (OTEC) is a marine renewable energy technology with the potential to contribute significantly to the baseload power needs of tropical island communities and remote U.S. military installations. As with other renewable energy technologies, however, there are potential challenges to its commercialization: technological, financial, social, and environmental. Given the large volumes of seawater required to drive the electricity-producing cycle, there is potential for the intakes to negatively impact the marine resources of the source waterbody through the impingement and entrainment of marine organisms. The goal of this project was to identify feasible warm water intake designs for a land-based OTEC facility proposed for development in Port Allen, Kauai and to characterize the populations of ichthyoplankton near the proposed warm water intake location that could be at risk of entrainment. The specific objectives of this project were to: • Complete a site-specific assessment of available and feasible warm water intake technologies to determine the best intake designs for minimizing impacts to aquatic organisms at the proposed land-based OTEC site in Port Allen, Kauai. • Complete a field sampling program to collect biological data to characterize the baseline populations of ichthyoplankton near the sites being considered for the warm water intake at the proposed land-based OTEC site in Port Allen, Kauai. Various intake design options are presented with the focus on providing adequate environmental protection to the local ichthyoplankton population while providing an economically viable intake option to the OTEC developer. Further definition by NOAA and other environmental regulators is required to further refine the designs presented to meet all US regulations for future OTEC development.

  19. Distribution and bioaccumulation of heavy metals in aquatic organisms of different trophic levels and potential health risk assessment from Taihu lake, China.

    PubMed

    Tao, Yu; Yuan, Zhang; Xiaona, Hu; Wei, Meng

    2012-07-01

    Aquatic organisms of different trophic levels were taken from Taihu lake. Heavy metals (Cu, Zn, Cr, Ni, Cd, Pb) were measured in phytoplankton, zooplankton, in two species of zoobenthos, and in eight fish species, as well as in the water column and bottom sediments. Results showed that the concentration of Cu and Zn for all organisms was much higher than for other metals, and Cd was the lowest in all species. Generally, heavy metal concentrations in phytoplankton were higher than in zooplankton. In zoobenthos, the concentration in Bellamya sp.(human edible snail) was higher than that in Corbiculidae (bivalve). Metal concentrations had no significant difference between fish species but tended to be higher in predator fish such as Coilia ectenes and Erythroculter ilishaeformis than in herbivorous fish. The level of measured metals in Taihu fish was moderate-low compared with that of fresh water fishes from international results. Spatially, metal concentrations in organisms were higher in the north and west Taihu lake but lower in south and east lake and this appears to be related to river inputs that are heavily influenced by anthropogenic activities. The bio-concentration factor (BCF) for all aquatic organisms in the food chain indicated that it was generally highest in planktons, followed by zoobenthos, and lowest in fish. Health risk assessment and comparison with national and international standards showed that consumption of aquatic products from the lake was generally safe but fishermen were a higher risk group especially through dietary intake of Bellamya sp.

  20. Static and dynamic removal of aquatic natural organic matter by carbon nanotubes.

    PubMed

    Ajmani, Gaurav S; Cho, Hyun-Hee; Abbott Chalew, Talia E; Schwab, Kellogg J; Jacangelo, Joseph G; Huang, Haiou

    2014-08-01

    Carbon nanotubes (CNTs) were investigated for their capability and mechanisms to simultaneously remove colloidal natural organic matter (NOM) and humic substances from natural surface water. Static removal testing was conducted via adsorption experiments while dynamic removal was evaluated by layering CNTs onto substrate membranes and filtering natural water through the CNT-layered membranes. Analyses of treated water samples showed that removal of humic substances occurred via adsorption under both static and dynamic conditions. Removal of colloidal NOM occurred at a moderate level of 36-66% in static conditions, independent of the specific surface area (SSA) of CNTs. Dynamic removal of colloidal NOM increased from approximately 15% with the unmodified membrane to 80-100% with the CNT-modified membranes. Depth filtration played an important role in colloidal NOM removal. A comparison of the static and dynamic removal of humic substances showed that equilibrium static removal was higher than dynamic (p < 0.01), but there was also a significant linear relationship between static and dynamic removal (p < 0.05). Accounting for contact time of CNTs with NOM during filtration, it appeared that CNT mat structure was an important determinant of removal efficiencies for colloidal NOM and humic substances during CNT membrane filtration.

  1. The effects of acrylamide polyelectrolytes on aquatic organisms: relating toxicity to chain architecture.

    PubMed

    Costa, R; Pereira, J L; Gomes, J; Gonçalves, F; Hunkeler, D; Rasteiro, M G

    2014-10-01

    Understanding the inherent toxicity of water-soluble synthetic polyelectrolytes is critical for adequate risk management as well as enhancing product design when biological activity is a key performance index (e.g. for application in biofouling bivalves' control). The toxicity of two cationic acrylamide copolymers with different chain branching degree was evaluated. Standard ecotoxicity tests were conducted with microalgae and daphnids. The susceptibility of Corbicula fluminea, as a biofouling bivalve, was also evaluated. The effect of polyelectrolyte on the test media viscosity and the polymer chain size distributions under the experimental conditions were also examined. The susceptibility of the microalgae to both polymers was similar. As the complexity and size of the test organisms increased, differences in toxicity due to different chain architecture were noticeable. The more branched polymer was significantly less toxic to both daphnids and the bivalves, which could be linked to the distinctive features of its bimodal size chain distribution. This architecture resulted in both more compact globular molecules and the formation of aggregates, which reduce the polymer interaction with the biological surfaces. The results of this study promote the incorporation of environmental considerations in polyelectrolyte development and contribute to the design of improved solutions for controlling biofouling bivalves.

  2. Toxicity of thiocyanate, phenol, and their mixtures to freshwater aquatic organisms: A mixture modeling approach

    SciTech Connect

    Soboslay, E.G.

    1987-01-01

    Thiocyanate and phenol are two environmentally significant constituents of wastewater streams from coke production plants and coal conversion facilities. Acute and chronic toxicity experiments were conducted for thiocyanate and phenol with Daphnia magna at 20 C and Ceriodaphnia affinis/dubia at 25C in hard water to study their individual toxic effects on survival and reproduction. Statistical analysis of the dose response relationships for the individual chemicals indicated the type of combined effects that occur when thiocyanate and phenol are present simultaneously. Mixture models for toxicant interaction were used to predict joint toxic effects on survival and reproduction. The applicability of the mixture model was tested by performing joint toxicity experiments for specific thiocyanate and phenol mixtures to verify the model for toxic effects on specific whole organism performances. Neonate production and hatchability, two indices of reproduction, were selected to evaluate the chronic toxic effects of thiocyanate and phenol. The resulting dose response curves for mixtures were compared to curves predicted on the basis of the mathematical model for concentration addition. Low concentrations of thiocyanate, phenol and their mixtures generally caused a stimulation effect on D. magna and C. affinis/dubia reproduction.

  3. Photoproduction of hydrated electrons from natural organic solutes in aquatic environments

    USGS Publications Warehouse

    Zepp, R.G.; Braun, A.M.; Hoigne, J.; Leenheer, J.A.

    1987-01-01

    Laser flash photolysis was used to investigate the transients formed on absorption of 355-nm light by dissolved organic matter (DOM) from natural water bodies and from soil. Absorption spectra and quenching studies of the transients provided confirming evidence that hydrated electrons were formed by all of the DOM that were studied. The DOM from the Suwannee River in Georgia and from the Greifensee, a Swiss lake, exhibited great variability in light-absorbing properties. Despite this high variability in absorption coefficients, the primary quantum yields for electron ejection from the Greifensee and Suwannee DOM fell in a narrow range (0.005-0.008). Steady-state irradiations (355 nm) of the DOM with 2-chloroethanol (0.02 M) present as an electron scavenger produced chloride ions with quantum yields that were about 2 orders of magnitude lower than the primary quantum yields. This result indicates that most of the photoejected electrons recombine with cations before escaping into bulk solution. Irradiations of DOM solutions under sunlight (April, latitude 34?? N) photoproduced electrons at rates falling in the range of 0.2-0.4 ??mol/[(mg of DOC) h]. These results indicate that hydrated electrons can play a significant role in the environmental photoreduction of persistent, electronegative pollutants but may be relatively unimportant in the environmental production of hydrogen peroxide. ?? 1987 American Chemical Society.

  4. Using solid 13C NMR coupled with solution 31P NMR spectroscopy to investigate molecular species and lability of organic carbon and phosphorus from aquatic plants in Tai Lake, China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquatic plants are involved in the storage and release capacity for organic matter and nutrients. In this study, solid 13C and solution 31P nuclear magnetic resonance (NMR) spectroscopy were used to characterize the biomass samples of six aquatic plants. Solid 13C NMR spectroscopy revealed the domin...

  5. Genetic and antigenic analysis of betanodaviruses isolated from aquatic organisms in Taiwan.

    PubMed

    Chi, S C; Shieh, J R; Lin, S J

    2003-08-04

    Viral nervous necrosis (VNN) is a worldwide disease among marine fishes. In Taiwan, NNN disease was first identified in 2 species of hatchery-reared grouper, Epinephelus fuscogutatus and E. akaaya in 1994. Since then, increasing mortalities have occurred among groupers Epinephelus spp., and also among European eels Anguilla anguilla L., yellow-wax pompano Trachinotus falcatus, firespot snapper Lutaanus erythropterus B., barramundi Lates calcarifer, cobias Rachycentron canadum, humpback groupers Cromileptes altivelis and Chinese catfish Parasilurus asotus. In the present study, samples were collected from affected fishes and processed for reverse transcriptase (RT) PCR amplification and virus isolation in cell culture. Infected cells (GF-1 cell line) exhibited cytopathic-effect characteristics of grouper nervous necrosis virus (GNNV). A RT-PCR product of approximately 830 bp was amplified from the brain homogenate of tested samples and sequenced. The nucleotide and deduced amino acid sequences of the amplified RT-PCR products from all isolates were strongly homologous (> 97 %) with the corresponding region of the published sequence of red-spotted grouper nervous necrosis virus (RGNVV). Therefore, all Taiwan NNV (nervous necrosis virus) isolates studied in this report belong to the RGNNV genotype. We used 5 neutralizing monoclonal antibodies (MAbs) against GNNV to analyze the antigenic relationship of Taiwan NNV isolates and striped jack nervous necrosis virus (SJNNV). The results of neutralization tests revealed that all Taiwan NNV isolates were closely related, but antigenically different from SJNNV in 3 neutralizing epitopes. To our knowledge, this is the first description of NNV infection in European eels, yellow-wax pompano, firespot snapper, cobia and Chinese catfish, and the first reported instance of natural NNV infection in freshwater fishes causing high mortality.

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

    PubMed

    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.

  7. Environmental effects and aquatic organisms: investigations of molecular mechanisms of carcinogenesis.

    PubMed Central

    Van Beneden, R J

    1997-01-01

    Cancers of the reproductive system are among the leading causes of mortality in women in the United States. While both genetic and environmental factors have been implicated in their etiology, the extent of the contribution of environmental factors to human diseases remains controversial. To better address the role of environmental exposures in cancer etiology, there has been an increasing focus on the development of nontraditional, environmentally relevant models. Our research involves the development of one such model. Gonadal tumors have been described in the softshell clam (Mya arenaria) in Maine and the hardshell clam (Mercenaria spp.) from Florida. Prevalence of these tumors is as high as 40% in some populations in eastern Maine and 60% in some areas along the Indian River in Florida. The average tumor prevalence in Maine and Florida is approximately 20 and 11%, respectively. An association has been suggested between the use of herbicides and the incidence of gonadal tumors in the softshell clam in Maine. The role of environmental exposures in the development of the tumors in Mercenaria in Florida is unknown; however, there is evidence that genetic factors may contribute to its etiology. Epidemiologic studies of human populations in these same areas show a higher than average mortality rate due to cancers of the reproductive system in women, including both ovarian and breast cancer. The relationship, if any, among these observations is unknown. Our studies on the molecular basis of this disease in clams may provide additional information on environmental exposures and their possible link to cancer in clams and other organisms, including humans. Images Figure 1. A Figure 1. B PMID:9168012

  8. Toxic Effect of a Marine Bacterium on Aquatic Organisms and Its Algicidal Substances against Phaeocystis globosa

    PubMed Central

    Yang, Qiuchan; Chen, Lina; Hu, Xiaoli; Zhao, Ling; Yin, Pinghe; Li, Qiang

    2015-01-01

    Harmful algal blooms have caused enormous damage to the marine ecosystem and the coastal economy in China. In this paper, a bacterial strain B1, which had strong algicidal activity against Phaeocystis globosa, was isolated from the coastal waters of Zhuhai in China. The strain B1 was identified as Bacillus sp. on the basis of 16S rDNA gene sequence and morphological characteristics. To evaluate the ecological safety of the algicidal substances produced by strain B1, their toxic effects on marine organisms were tested. Results showed that there were no adverse effects observed in the growth of Chlorella vulgaris, Chaetoceros muelleri, and Isochrystis galbana after exposure to the algicidal substances at a concentration of 1.0% (v/v) for 96 h. The 48h LC50 values for Brachionus plicatilis, Moina mongolica Daday and Paralichthys olivaceus were 5.7, 9.0 and 12.1% (v/v), respectively. Subsequently, the algicidal substances from strain B1 culture were isolated and purified by silica gel column, Sephadex G-15 column and high-performance liquid chromatography. Based on quadrupole time-of-flight mass spectrometry and PeakView Software, the purified substances were identified as prolyl-methionine and hypoxanthine. Algicidal mechanism indicated that prolyl-methionine and hypoxanthine inhibited the growth of P. globosa by disrupting the antioxidant systems. In the acute toxicity assessment using M. mongolica, 24h LC50 values of prolyl-methionine and hypoxanthine were 7.0 and 13.8 g/L, respectively. The active substances produced by strain B1 can be considered as ecologically and environmentally biological agents for controlling harmful algal blooms. PMID:25646807

  9. Organic and total mercury in muscle tissue of five aquatic birds with different feeding habits from the SE Gulf of California, Mexico.

    PubMed

    Ruelas-Inzunza, J; Hernández-Osuna, J; Páez-Osuna, F

    2009-07-01

    We measured organic and total Hg in muscle tissue of five species of aquatic birds from the south-eastern gulf of California region, Mexico. Concentrations of total and organic Hg measured in Pelecanus occidentalis were the highest (2.85 and 2.68 microgg(-1)); lowest values of organic Hg (0.20 microgg(-1)) and total Hg (0.47 microgg(-1)) were detected in Anas discors and Anas clypeata, respectively. Differences of Hg levels were related to feeding habits, being concentrations in birds of piscivorous habits more elevated than corresponding values in non-piscivorous species.

  10. Bioconcentration and toxicity of dodecylbenzene sulfonate (C12LAS) to aquatic organisms exposed in experimental streams.

    PubMed

    Versteeg, D J; Rawlings, J M

    2003-02-01

    Fish, mollusks, and crustaceans were caged in the tail pool of streams during a C(12)LAS (dodecyl benzene sulfonate) model ecosystem experimental program. Bioconcentration of total C(12)LAS and individual isomers and acute and chronic toxicity were investigated during this study. Toxicity endpoints were based on water and tissue (i.e., body burden) concentrations at which adverse effects were observed. At 32 days, total C(12)LAS bioconcentration factors (BCFs) for the fathead minnow and three invertebrate species ranged from 9 to 116. In general, bioconcentration was affected by isomer position, exposure concentration, and species. BCF values tended to decrease as isomer position moved from external (e.g., 2-phenyl) to internal (e.g., 5,6-phenyl). BCFs also decreased as exposure concentration increased. Mean acute 4-d LC(50) values ranged from 1.5 to >3.0 mg/L for the six species tested. Lethal body burdens associated with 50% mortality (LBB(50)) varied from 0.21 to 0.60 mmole/kg (wet weight). During the 32-day chronic exposures, the EC(20) values were 0.27 (0.204-0.352), 0.95 (0.597-1.29), and approximately 1.0 mg/L for Corbicula (length), Hyalella (survival), and fathead minnow (survival), respectively. At these EC(20) values, C(12)LAS body burdens were 0.035, 0.23, and 0.19 mmoles/kg wet weight in Corbicula, Hyalella, and fathead minnow, respectively. Fish exposed to wastewater treatment plant effluent had total C(12)LAS tissue concentrations ranging from 0.0005 to 0.0039 mmoles/kg wet weight. These concentrations are approximately 45-360 times below the tissue concentration associated with subtle effects in the model ecosystem stream exposures. Total C(12)LAS body burdens in feral and caged Corbicula exposed to WWTP effluents were approximately 0.0013 mmoles/kg; approximately 25-fold below concentrations associated with effects in stream exposures.

  11. Ultrafiltration separation of aquatic natural organic matter: chemical probes for quality assurance.

    PubMed

    Revchuk, Alex D; Suffet, I H Mel

    2009-08-01

    Characterization of molecular size of natural organic matter (NOM) is a valuable tool when assessing its effect on the performance of water treatment systems as well as its geochemical origin. Size fractionation can be accomplished by ultrafiltration (UF). Unfortunately, membrane manufacturing generates a range of pore sizes. Many membrane manufacturers use molecular weight cutoff (MWCO) metric based on a 90% retention of given solute after specified duration of filtration. The objective of this study was to characterize the ability of different commercially available UF membranes to separate different size fractions of NOM. The UF membranes characterized were YM (regenerated cellulose, negatively charged) and PB (polyethersulfone, negatively charged) product lines by Millipore. The probes used to represent the size, shape and charge of NOM were polymers (polyethylene glycols (PEGs), dextrans, polystyrene sulfonates (PSSs)), dyes (bromocresol green, congo red, methyl red, methyl orange) and biological molecules (vitamin B-12 and bacitracin). The results show that MWCO definition does not hold for membranes of 5kDa and 10kDa pore openings using most polymers and dyes. The MWCO definition holds for 1kDa membrane for all tested probes. Under natural water conditions PSSs assume random coil configurations that are nearly identical to Suwannee fulvic acid. The results show that PSS agrees with stated MWCOs. The study demonstrates that ultrafiltration is not a simple mechanical sieving process, but that charges on the membrane and the constituent play a significant role in the rejection process. Effective probe size was increased seven- to fourteen-fold by charge interactions between the negative probes and negatively charged membrane. Uncharged molecules larger than specified MWCOs are able to pass through pores (PEGs), while small charged molecules (dyes) do not pass. For probes with low or neutral charges, shape becomes an important factor, with globular being favored

  12. Organic matter loading affects lodgepole pine seedling growth.

    PubMed

    Wei, Xiaohua; Li, Qinglin; Waterhouse, M J; Armleder, H M

    2012-06-01

    Organic matter plays important roles in returning nutrients to the soil, maintaining forest productivity and creating habitats in forest ecosystems. Forest biomass is in increasing demand for energy production, and organic matter has been considered as a potential supply. Thus, an important management question is how much organic matter should be retained after forest harvesting to maintain forest productivity. To address this question, an experimental trial was established in 1996 to evaluate the responses of lodgepole pine seedling growth to organic matter loading treatments. Four organic matter loading treatments were randomly assigned to each of four homogeneous pine sites: removal of all organic matter on the forest floor, organic matter loading quantity similar to whole-tree-harvesting residuals left on site, organic matter loading quantity similar to stem-only-harvesting residuals, and organic matter loading quantity more similar to what would be found in disease- or insect-killed stands. Our 10-year data showed that height and diameter had 29 and 35 % increase, respectively, comparing the treatment with the most organic matter loading to the treatment with the least organic matter loading. The positive response of seedling growth to organic matter loading may be associated with nutrients and/or microclimate change caused by organic matter, and requires further study. The dynamic response of seedling growth to organic matter loading treatments highlights the importance of long-term studies. Implications of those results on organic matter management are discussed in the context of forest productivity sustainability.

  13. Organic Matter Loading Affects Lodgepole Pine Seedling Growth

    NASA Astrophysics Data System (ADS)

    Wei, Xiaohua; Li, Qinglin; Waterhouse, M. J.; Armleder, H. M.

    2012-06-01

    Organic matter plays important roles in returning nutrients to the soil, maintaining forest productivity and creating habitats in forest ecosystems. Forest biomass is in increasing demand for energy production, and organic matter has been considered as a potential supply. Thus, an important management question is how much organic matter should be retained after forest harvesting to maintain forest productivity. To address this question, an experimental trial was established in 1996 to evaluate the responses of lodgepole pine seedling growth to organic matter loading treatments. Four organic matter loading treatments were randomly assigned to each of four homogeneous pine sites: removal of all organic matter on the forest floor, organic matter loading quantity similar to whole-tree-harvesting residuals left on site, organic matter loading quantity similar to stem-only-harvesting residuals, and organic matter loading quantity more similar to what would be found in disease- or insect-killed stands. Our 10-year data showed that height and diameter had 29 and 35 % increase, respectively, comparing the treatment with the most organic matter loading to the treatment with the least organic matter loading. The positive response of seedling growth to organic matter loading may be associated with nutrients and/or microclimate change caused by organic matter, and requires further study. The dynamic response of seedling growth to organic matter loading treatments highlights the importance of long-term studies. Implications of those results on organic matter management are discussed in the context of forest productivity sustainability.

  14. Comparing resource pulses in aquatic and terrestrial ecosystems.

    PubMed

    Nowlin, Weston H; Vanni, Michael J; Yang, Louie H

    2008-03-01

    Resource pulses affect productivity and dynamics in a diversity of ecosystems, including islands, forests, streams, and lakes. Terrestrial and aquatic systems differ in food web structure and biogeochemistry; thus they may also differ in their responses to resource pulses. However, there has been a limited attempt to compare responses across ecosystem types. Here, we identify similarities and differences in the causes and consequences of resource pulses in terrestrial and aquatic systems. We propose that different patterns of food web and ecosystem structure in terrestrial and aquatic systems lead to different responses to resource pulses. Two predictions emerge from a comparison of resource pulses in the literature: (1) the bottom-up effects of resource pulses should transmit through aquatic food webs faster because of differences in the growth rates, life history, and stoichiometry of organisms in aquatic vs. terrestrial systems, and (2) the impacts of resource pulses should also persist longer in terrestrial systems because of longer generation times, the long-lived nature of many terrestrial resource pulses, and reduced top-down effects of consumers in terrestrial systems compared to aquatic systems. To examine these predictions, we use a case study of a resource pulse that affects both terrestrial and aquatic systems: the synchronous emergence of periodical cicadas (Magicicada spp.) in eastern North American forests. In general, studies that have examined the effects of periodical cicadas on terrestrial and aquatic systems support the prediction that resource pulses transmit more rapidly in aquatic systems; however, support for the prediction that resource pulse effects persist longer in terrestrial systems is equivocal. We conclude that there is a need to elucidate the indirect effects and long-term implications of resource pulses in both terrestrial and aquatic ecosystems.

  15. Soil organic matter composition affected by potato cropping managements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic matter is a small but important soil component. As a heterogeneous mixture of geomolecules and biomolecules, soil organic matter (SOM) can be fractionated into distinct pools with different solubility and lability. Water extractable organic matter (WEOM) fraction is the most labile and mobil...

  16. Biomagnification of persistent organic pollutants along a high-altitude aquatic food chain in the Tibetan Plateau: Processes and mechanisms.

    PubMed

    Ren, Jiao; Wang, Xiaoping; Wang, Chuanfei; Gong, Ping; Wang, Xiruo; Yao, Tandong

    2017-01-01

    Biomagnification of some persistent organic pollutants (POPs) has been found in marine and freshwater food chains; however, due to the relatively short food chains in high-altitude alpine lakes, whether trophic transfer would result in the biomagnification of POPs is not clear. The transfer of various POPs, including organochlorine pesticides and polychlorinated biphenyls (PCBs), along the aquatic food chain in Nam Co Lake (4700 m), in the central Tibetan Plateau, was studied. The POPs levels in the water, sediment and biota [plankton, invertebrates and fish (Gymnocypris namensis)] of Nam Co were generally low, with concentrations comparable to those reported for the remote Arctic. The composition profiles of POPs in the fish were different from that in the water, but similar to their food. DDEs, DDDs, PCB 138, 153 and 180 displayed significant positive correlations with trophic levels, with trophic magnification factors (TMFs) ranged between 1.5 and 4.2, implying these chemicals can undergo final biomagnification along food chain. A fugacity-based dynamic bioaccumulation model was applied to the fish with localized parameters, by which the simulated concentrations were comparable to the measured data. Modeling results showed that most compounds underwent net gill loss and net gut uptake; only when the net result of the combined gut and gill fluxes would be positive, bioaccumulation could eventually occur. The net accumulation flux increased with fish age, which was caused by the continuous increase of gut uptake by aged fish. Due to the oligotrophic condition, efficient food absorption is likely the key factor that influences the gut POPs uptake. Long residence times with half-lives up to two decades were found for the higher chlorinated PCBs in Gymnocypris namensis.

  17. Interference of single walled carbon nanotubes (SWCNT) in the measurement of lipid peroxidation in aquatic organisms through TBARS assay.

    PubMed

    Monserrat, J M; Seixas, A L R; Ferreira-Cravo, M; Bürguer-Mendonça, M; Garcia, S C; Kaufmann, C G; Ventura-Lima, J

    2017-06-01

    Nanomaterials (NM) exhibit unique properties due their size and relative area, but the mechanisms and effects in the living organisms are yet to be unfold in their totality. Potential toxicity mechanisms concerning NM as carbon nanotubes include oxidative stress generation. Several fluorimetric and colorimetric methods have been systematically used to measure NM toxicity, and controversial results have been reported. One of the problems can be related to the interference effects induced by NM, leading to artifacts that can lead to misleading conclusions. In present study, it was performed in vitro assays with two aquatic species: the zebrafish Danio rerio and the polychaete Laeonereis acuta to evaluate the potential interference capacity of single-wall carbon nanotubes (SWCNT) in a fluorometric method (TBARS assay) to measure lipid peroxidation. Obtained results indicated that gills and brain of zebrafish presented a lowered fluorescence only at extremely high concentrations (50 and 500mg/L). Determinations in anterior, middle, and posterior body regions of L. acuta showed a quite different pattern: high fluorescence at low SWCNT concentrations (0.5mg/L) and lowering at the highest (500mg/L). To eliminate matrix effect of biological samples, tests employing the standard for TBARS assay, 1,3,3-tetramethoxipropane, were run and the results showed again higher fluorescence values at low concentrations (0.5-5mg SWCNT/L), a technique artifact that could lead to misleading conclusions since higher fluorescence values implicate higher TBARS concentration, implying oxidative stress. Using the colorimetric FOX assay with cumene hydroperoxide as standard presented remarkable better results since no artifacts were observed in the same SWCNT concentration range that employed with the TBARS technique.

  18. AQUATIC ECOSYSTEMS,

    EPA Science Inventory

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

  19. Aquatic Environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquatic microbiology can be defined as the study of microorganisms and microbial communities in water environments. Aquatic environments occupy more than 70% of the earth’s surface including oceans, estuaries, rivers, lakes, wetlands, streams, springs, and aquifers. Water is essential for life and m...

  20. Fisheries and aquatic resources--fish health

    USGS Publications Warehouse

    Panek, Frank

    2008-01-01

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

  1. Species and biogeochemical cycles of organic phosphorus in sediments from a river with different aquatic plants located in Huaihe River Watershed, China.

    PubMed

    Yuan, He Zhong; Pan, Wei; Ren, Li Jun; Liu, Eeng Feng; Shen, Ji; Geng, Qi Fang; An, Shu Qing

    2015-01-01

    The results of phosphorus fractionation in the sediments from a contaminated river containing different aquatic plants, analyzed by solution 31P-NMR for Organic Phosphorus, showed that the concentration of Inorganic Phosphorus dominated in all species and Organic Phosphorus accounted for over 20% of Total Phosphorus. In general, orthophosphate was dominant in all the sampling sites. The proportion of Organic Phosphorus accounting for the Total Phosphorus in the sediments with different plant decreased in the following order: Paspalum distichum>Typha orientalis>Hydrilla verticillata. Phosphorus-accumulation ability of Paspalum distichum was obviously stronger than Typha orientalis and Hydrilla verticillata. The Organic Phosphorus was in aquatic plants dominated by humic-associated P (Hu-P), which converted to Inorganic Ohosphorus more significantly in submerged plants than in emerged plants. The sediment dominated by Paspalum distichum abundantly accumulated Organic Phosphorus in the orthophosphate monoester fraction. The degradation and mineralization of orthophosphate monoester was the important source of high Inorganic Phosphorus concentration and net primary productivity in Suoxu River. The Organic Phosphorus derived from Typha orientalis and Hydrilla verticillata was dramatically converted to Inorganic Phosphorus when the environmental factors varied.

  2. Assessment of advective porewater movement affecting mass transfer of hydrophobic organic contaminants in marine intertidal sediment.

    PubMed

    Cho, Yeo-Myoung; Werner, David; Moffett, Kevan B; Luthy, Richard G

    2010-08-01

    Advective porewater movement and molecular diffusion are important factors affecting the mass transfer of hydrophobic organic compounds (HOCs) in marsh and mudflat sediments. This study assessed porewater movement in an intertidal mudflat in South Basin adjacent to Hunters Point Shipyard, San Francisco, CA, where a pilot-scale test of sorbent amendment assessed the in situ stabilization of polychlorinated biphenyls (PCBs). To quantify advective porewater movement within the top 0-60 cm sediment layer, we used temperature as a tracer and conducted heat transport analysis using 14-day data from multidepth sediment temperature logging stations and one-dimensional heat transport simulations. The best-fit conditions gave an average Darcy velocity of 3.8cm/d in the downward vertical direction for sorbent-amended sediment with a plausible range of 0 cm/d to 8 cm/d. In a limiting case with no net advection, the best-fit depth-averaged mechanical dispersion coefficient was 2.2x10(-7) m2/s with a range of 0.9x10(-7) m2/s to 5.6x10(-7) m2/s. The Peclet number for PCB mobilization showed that molecular diffusion would control PCB mass transfer from sediment to sorbent particles for the case of uniform distribution of sorbent. However, the advective flow and mechanical dispersion in the test site would significantly benefit the stabilization effect of heterogeneously distributed sorbent by acting to smooth out the heterogeneities and homogenizing pollutant concentrations across the entire bioactive zone. These measurements and modeling techniques on intertidal sediment porewater transport could be useful for the development of more reliable mass transfer models for the prediction of contaminant release within the sediment bed, the movement of HOCs in the intertidal aquatic environment, and in situ sequestration by sorbent addition.

  3. Gadolinium-uptake by aquatic and terrestrial organisms-distribution determined by laser ablation inductively coupled plasma mass spectrometry.

    PubMed

    Lingott, Jana; Lindner, Uwe; Telgmann, Lena; Esteban-Fernández, Diego; Jakubowski, Norbert; Panne, Ulrich

    2016-02-01

    Gadolinium (Gd) based contrast agents (CA) are used to enhance magnetic resonance imaging. As a consequence of excretion by patients and insufficient elimination in wastewater treatment plants they are detected in high concentrations in surface water. At present, little is known about the uptake of these species by living organisms in aquatic systems. Therefore the uptake of gadolinium containing chelates by plants and animals grown in exposed water or on soil irrigated with exposed water was investigated. For this purpose two types of plants were treated with two different contrast agents. The uptake of the Gd contrast agents was studied by monitoring the elemental distribution with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). This technique allows the multi-elemental analysis of solid samples with high resolution and little sample preparation. The analysis of L. minor showed that the uptake of Gd correlated with the concentration of gadodiamide in the water. The higher the concentration in the exposed water, the larger the Gd signal in the LA-ICP-MS acquired image. Exposure time experiments showed saturation within one day. The L. minor had contact with the CAs through roots and fronds, whereas the L. sativum only showed uptake through the roots. These results show that an external absorption of the CA through the leaves of L. sativum was impossible. All the analyzed parts of the plant showed Gd signal from the CA; the highest being at the main vein of the leaf. It is shown that the CAs can be taken up from plants. Furthermore, the uptake and distribution of Gd in Daphnia magna were shown. The exposure via cultivation medium is followed by Gd signals on the skin and in the area of the intestine, while the uptake via exposed nutrition algae causes the significantly highest Gd intensities in the area of the intestine. Because there are hints of negative effects for human organism these findings are important as they show that Gd based

  4. Dissolved organic carbon content and characteristics in relation to carbon dioxide partial pressure across Poyang Lake wetlands and adjacent aquatic systems in the Changjiang basin.

    PubMed

    Wang, Huaxin; Jiao, Ruyuan; Wang, Fang; Zhang, Lu; Yan, Weijin

    2016-12-01

    Dissolved organic carbon (DOC) plays diverse roles in carbon biogeochemical cycles. Here, we explored the link between DOC and pCO2 using high-performance size-exclusion chromatography (HPSEC) with UV254 detection and excitation emission matrix (EEM) fluorescence spectroscopy to determine the molecular weight distribution (MW) and the spectral characteristics of DOC, respectively. The relationship between DOC and pCO2 was investigated in the Poyang Lake wetlands and their adjacent aquatic systems. The results indicated significant spatial variation in the DOC concentrations, MW distributions, and pCO2. The DOC concentration was higher in the wetlands than in the rivers and lakes. pCO2 was high in wetlands in which the dominant vegetation was Phragmites australis, whereas it was low in wetlands in which Carex tristachya was the dominant species. DOC was divided into five fractions according to MW, as follows: super-low MW (SLMW, <1 kDa); low MW (LMW, 1-2.5 kDa); intermediate MW (IMW, 2.5-3.5 kDa); high MW (HMW, 3.5-6 kDa); and super-high MW (SMW, > 40 kDa). Rivers contained high proportions of HMW and extremely low amounts of SLMW, whereas wetlands had relatively high proportions of SLMW. The proportion of SMW (SMWp) was particularly high in wetlands. We found that pCO2 significantly positively correlated with the proportion of IMW, and significantly negatively correlated with SMWp. These data improve our understanding of the MW of bioavailable DOC and its conversion to CO2. The present results demonstrate that both the content and characteristics of DOC significantly affect pCO2. pCO2 and DOC must be studied further to help understanding the role of the wetland on the regional CO2 budget.

  5. Summary of national standards and guidelines for pesticides in water, bed sediment, and aquatic organisms and their application to water-quality assessments

    USGS Publications Warehouse

    Nowell, Lisa H.; Resek, Elizabeth A.

    1994-01-01

    Current (1993) national standards and guidelines pertaining to pesticide contaminants in water, bed sediment, and fish and shellfish tissues are summarized to provide a condensed reference source for definitions and current values applicable to pesticides in aquatic environmental media. This report facilitates comparison of measured concen- trations of pesticides in environmental samples with applicable standards and guidelines. For each standard or guideline, the following is provided: (1) Definition, including the underlying assumptions and mathematical derivation; (2) originating agency; (3) statutory authority; (4) regulatory status and, for standards, the agency responsible for enforcing the standard; (5) applicable sampling medium; (6) beneficial use and resource protected, and (7) full citations of published documentation. The report emphasizes the appropriate application on national standards and guidelines to water-quality data on pesticides to aid in assessing potential adverse effects on human health, aquatic organisms, and wildlife. (USGS)

  6. Technical issues affecting the implementation of US Environmental Protection Agency's proposed fish tissue-based aquatic criterion for selenium.

    PubMed

    Lemly, A Dennis; Skorupa, Joseph P

    2007-10-01

    The US Environmental Protection Agency is developing a national water quality criterion for selenium that is based on concentrations of the element in fish tissue. Although this approach offers advantages over the current water-based regulations, it also presents new challenges with respect to implementation. A comprehensive protocol that answers the "what, where, and when" is essential with the new tissue-based approach in order to ensure proper acquisition of data that apply to the criterion. Dischargers will need to understand selenium transport, cycling, and bioaccumulation in order to effectively monitor for the criterion and, if necessary, develop site-specific standards. This paper discusses 11 key issues that affect the implementation of a tissue-based criterion, ranging from the selection of fish species to the importance of hydrological units in the sampling design. It also outlines a strategy that incorporates both water column and tissue-based approaches. A national generic safety-net water criterion could be combined with a fish tissue-based criterion for site-specific implementation. For the majority of waters nationwide, National Pollution Discharge Elimination System permitting and other activities associated with the Clean Water Act could continue without the increased expense of sampling and interpreting biological materials. Dischargers would do biotic sampling intermittently (not a routine monitoring burden) on fish tissue relative to the fish tissue criterion. Only when the fish tissue criterion is exceeded would a full site-specific analysis including development of intermedia translation factors be necessary.

  7. Assessment of toxicity thresholds in aquatic environments: does benthic growth of diatoms affect their exposure and sensitivity to herbicides?

    PubMed

    Larras, Floriane; Montuelle, Bernard; Bouchez, Agnès

    2013-10-01

    Benthic diatoms evolved in a biofilm structure, at the interface between water and substrata. Biofilms can adsorb toxicants, such as herbicides, but little is known about the exposure of biofilm organisms, such as benthic diatoms, to these adsorbed herbicides. We assessed the sensitivity of 11 benthic diatoms species to 6 herbicides under both planktonic and benthic conditions using single-species bioassays. The concentration that reduced the growth rate of the population by 10% (EC10) and 50% (EC50), respectively, varied depending on the species, the herbicides, and the growth forms involved. As a general trend, the more hydrophobic the herbicide, the more species were found to be sensitive under benthic growth conditions. Statistical differences (alpha<5%) were observed between the sensitivities under planktonic and benthic growth conditions for many hydrophobic herbicides. A protective effect of the biofilm against herbicides was observed, and this tended to decrease (at both the EC10 and EC50 levels) with increasing hydrophobicity. The biofilm matrix appeared to control exposure to herbicides, and consequently their toxicity towards benthic diatoms. For metolachlor, terbutryn and irgarol, benthic thresholds derived from species sensitivity distributions were more protective than planktonic thresholds. For hydrophobic herbicides, deriving sensitivity thresholds from data obtained under benthic growth seems to offer a promising alternative.

  8. Economic comparison of two application methods for potential organic control of duckweed utilizing pelargonic acid as an aquatic herbicide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Duckweeds (Lemna spp.) are small, free floating, aquatic plants that flourish on stagnant or slow moving, water surfaces throughout the world. Members of the genus are among the smallest flowering plants, providing food for fish and fowl, but their aggressive growth and invasive tendencies make the...

  9. Comparison of two application methods for potential organic control of duckweed utilizing pelargonic acid as an aquatic herbicide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Duckweeds (Lemna spp.) are small, free-floating, aquatic plants that flourish on stagnant or slow moving water surfaces throughout the world. Members of the genus are among the smallest flowering plants, providing food for fish and fowl. But their aggressive growth and invasive tendencies make them...

  10. Economic comparison of two application methods for potential organic control of duckweed utilizing pelargonic acid as an aquatic herbicide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Duckweeds (Lemna spp.) are small, free-floating, aquatic plants that flourish on stagnant or slow-moving water surfaces throughout the world. Members of the genus are among the smallest flowering plants, providing food for fish and fowl, but their aggressive growth and invasive tendencies make them...

  11. Aquatic Plants Aid Sewage Filter

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.

    1985-01-01

    Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

  12. Exposure to organic solvents. Does it adversely affect pregnancy?

    PubMed Central

    McMartin, K. I.; Koren, G.

    1999-01-01

    QUESTION: One of my patients is a laboratory technician who routinely handles organic solvents. She has just learned that she is pregnant, and she depends very much on this job because her husband is unemployed. What is the risk to her unborn baby? ANSWER: Available epidemiologic data indicate your patient's fetus might be at increased risk for malformations. We recommend that she minimize her occupational exposure to organic solvents by routinely using ventilation systems and protective equipment. This is most important during the first trimester of pregnancy. PMID:10424263

  13. Schizotypy as An Organizing Framework for Social and Affective Sciences

    PubMed Central

    Cohen, Alex S.; Mohr, Christine; Ettinger, Ulrich; Chan, Raymond C. K.; Park, Sohee

    2015-01-01

    Schizotypy, defined in terms of commonly occurring personality traits related to the schizophrenia spectrum, has been an important construct for understanding the neurodevelopment and stress-diathesis of schizophrenia. However, as schizotypy nears its sixth decade of application, it is important to acknowledge its impressively rich literature accumulating outside of schizophrenia research. In this article, we make the case that schizotypy has considerable potential as a conceptual framework for understanding individual differences in affective and social functions beyond those directly involved in schizophrenia spectrum pathology. This case is predicated on (a) a burgeoning literature noting anomalies in a wide range of social functioning, affiliative, positive and negative emotional, expressive, and social cognitive systems, (b) practical and methodological features associated with schizotypy research that help facilitate empirical investigation, and (c) close ties to theoretical constructs of central importance to affective and social science (eg, stress diathesis, neural compensation). We highlight recent schizotypy research, ie providing insight into the nature of affective and social systems more generally. This includes current efforts to clarify the neurodevelopmental, neurobiological, and psychological underpinnings of affiliative drives, hedonic capacity, social cognition, and stress responsivity systems. Additionally, we discuss neural compensatory and resilience factors that may mitigate the expression of stress-diathesis and functional outcome, and highlight schizotypy’s potential role for understanding cultural determinants of social and affective functions. PMID:25810057

  14. Microbial Community Analysis in the Roots of Aquatic Plants and Isolation of Novel Microbes Including an Organism of the Candidate Phylum OP10

    PubMed Central

    Tanaka, Yasuhiro; Tamaki, Hideyuki; Matsuzawa, Hiroaki; Nigaya, Masahiro; Mori, Kazuhiro; Kamagata, Yoichi

    2012-01-01

    A number of molecular ecological studies have revealed complex and unique microbial communities in various terrestrial plant roots; however, little is known about the microbial communities of aquatic plant roots in spite of their potential use for water quality improvement in aquatic environments (e.g. floating treatment wetland system). Here, we report the microbial communities inhabiting the roots of emerged plants, reed (Phragmites australis) and Japanese loosestrife (Lythrum anceps), collected from a floating treatment wetland in a pond by both culture-independent and culture-dependent approaches. Culture-independent analysis based on 16S rRNA gene sequences revealed that the microbial compositions between the two aquatic plant roots were clearly different (e.g. the predominant microbe was Betaproteobacteria for reed and Alphaproteobacteria for Japanese loosestrife). In comparisons of microbial communities between the plant roots and pond water taken from near the plants, the microbial diversity in the plant roots (e.g. 4.40–4.26 Shannon-Weiner index) were higher than that of pond water (e.g. 3.15 Shannon-Weiner index). Furthermore, the plant roots harbored 2.5–3.5 times more phylogenetically novel clone phylotypes than pond water. The culture-dependent approach also revealed differences in the microbial composition and diversity among the two plant roots and pond water. More importantly, compared to pond water, we succeeded in isolating approximately two times more novel isolate phylotypes, including a bacterium of candidate phylum OP10 (recently named Armatimonadetes) from the plant roots. These findings suggest that aquatic plants roots are significant sources for a variety of novel organisms. PMID:22791047

  15. Microbial community analysis in the roots of aquatic plants and isolation of novel microbes including an organism of the candidate phylum OP10.

    PubMed

    Tanaka, Yasuhiro; Tamaki, Hideyuki; Matsuzawa, Hiroaki; Nigaya, Masahiro; Mori, Kazuhiro; Kamagata, Yoichi

    2012-01-01

    A number of molecular ecological studies have revealed complex and unique microbial communities in various terrestrial plant roots; however, little is known about the microbial communities of aquatic plant roots in spite of their potential use for water quality improvement in aquatic environments (e.g. floating treatment wetland system). Here, we report the microbial communities inhabiting the roots of emerged plants, reed (Phragmites australis) and Japanese loosestrife (Lythrum anceps), collected from a floating treatment wetland in a pond by both culture-independent and culture-dependent approaches. Culture-independent analysis based on 16S rRNA gene sequences revealed that the microbial compositions between the two aquatic plant roots were clearly different (e.g. the predominant microbe was Betaproteobacteria for reed and Alphaproteobacteria for Japanese loosestrife). In comparisons of microbial communities between the plant roots and pond water taken from near the plants, the microbial diversity in the plant roots (e.g. 4.40-4.26 Shannon-Weiner index) were higher than that of pond water (e.g. 3.15 Shannon-Weiner index). Furthermore, the plant roots harbored 2.5-3.5 times more phylogenetically novel clone phylotypes than pond water. The culture-dependent approach also revealed differences in the microbial composition and diversity among the two plant roots and pond water. More importantly, compared to pond water, we succeeded in isolating approximately two times more novel isolate phylotypes, including a bacterium of candidate phylum OP10 (recently named Armatimonadetes) from the plant roots. These findings suggest that aquatic plants roots are significant sources for a variety of novel organisms.

  16. Chloroform in the hydrologic system--sources, transport, fate, occurrence, and effects on human health and aquatic organisms

    USGS Publications Warehouse

    Ivahnenko, Tamara; Barbash, Jack E.

    2004-01-01

    Protection Agency (USEPA) for TTHMs. In the studies that compared land-use settings, frequencies of detection of chloroform were higher beneath urban and residential areas than beneath agricultural or undeveloped areas. Because chloroform is a suspected human carcinogen, its presence in drinking water is a potential human health concern. Liver damage, however, is known to occur at chloroform exposures lower than those required to cause cancer, an observation that has been considered by the USEPA as the basis for setting a new, non-zero Maximum Contaminant Level Goal of 70 ?g/L for the compound. As part of its National Water-Quality Assessment Program, the U.S. Geological Survey has been assembling and analyzing data on the occurrence of VOCs (including chloroform) in ground and surface water on a national scale from studies conducted between 1991 and the present. This report presents a summary of current (2004) information on the uses, sources, formation, transport, fate, and occurrence of chloroform, as well as its effects on human health and aquatic organisms.

  17. Aggregatibacter actinomycetemcomitans lipopolysaccharide affects human gingival fibroblast cytoskeletal organization.

    PubMed

    Gutiérrez-Venegas, Gloria; Contreras-Marmolejo, Luis Arturo; Román-Alvárez, Patricia; Barajas-Torres, Carolina

    2008-04-01

    The cytoskeleton is a dynamic structure that plays a key role in maintaining cell morphology and function. This study investigates the effect of bacterial wall lipopolysaccharide (LPS), a strong inflammatory agent, on the dynamics and organization of actin, tubulin, vimentin, and vinculin proteins in human gingival fibroblasts (HGF). A time-dependent study showed a noticeable change in actin architecture after 1.5 h of incubation with LPS (1 microg/ml) with the formation of orthogonal fibers and further accumulation of actin filament at the cell periphery by 24 h. When 0.01-10 microg/ml of LPS was added to human gingival fibroblast cultures, cells acquired a round, flat shape and gradually developed cytoplasmic ruffling. Lipopolysaccharides extracted from Aggregatibacter actinomycetemcomitans periodontopathogenic bacteria promoted alterations in F-actin stress fibres of human gingival cells. Normally, human gingival cells have F-actin fibres that are organized in linear distribution throughout the cells, extending along the cell's length. LPS-treated cells exhibited changes in cytoskeletal protein organization, and F-actin was reorganized by the formation of bundles underneath and parallel to the cell membrane. We also found the reorganization of the vimentin network into vimentin bundling after 1.5 h of treatment. HGF cells exhibited diffuse and granular gamma-tubulin stain. There was no change in LPS-treated HGF. However, vinculin plaques distributed in the cell body diminished after LPS treatment. We conclude that the dynamic and structured organization of cytoskeletal filaments and actin assembly in human gingival fibroblasts is altered by LPS treatment and is accompanied by a decrease in F-actin pools.

  18. The organic precursors affecting the formation of disinfection by-products with chlorine dioxide.

    PubMed

    Chang, C Y; Hsieh, Y H; Lin, Y M; Hu, P Y; Liu, C C; Wang, K H

    2001-08-01

    The object of this research was to study the formation of disinfection by-products by using chlorine dioxide (ClO2) as a disinfectant reacting with different properties of organic substance in natural aquatic environment. The adsorbent resin (XAD-4, XAD-7) was used to divide the organic matters in raw water into three groups. The influence of the function groups on structure, reaction tendency, and formation of disinfection by-products generated by the reaction of these organic substances with chlorine dioxide was explored. The experimental results show that the three different organic groups formed using adsorbent resin were hydrophobic substance, hydrophilic acid, and non-acid hydrophilics in proportions of 43%, 41%, and 16%, respectively. Within the raw water in our study, the hydrophilic substance had a higher distribution proportion than that described in general articles and journals, which indicates that this water was contaminated with pollution from human beings. The exploration of the reactivity of the three different organic substances with chlorine dioxide shows that the unit consumption of disinfection agent per unit organic matters (represented by ClO2/DOC) is in the following sequence hydrophobic substance > hydrophilic substance > non-acid hydrophilics. It indicated that larger molecular organic precursors had larger consumption of disinfectant. We also discovered that after the reaction of the three different organic substances with chlorine dioxide, the largest amount of disinfection by-products were generated by the non-acid hydrophilics.

  19. Role of Natural Organic Matter in Regulating the Partitioning of Th(IV) and Pa(IV, V) on Aquatic Colloids and Nanoparticles

    NASA Astrophysics Data System (ADS)

    Guo, L.; Roberts, K. A.; Santschi, P. H.

    2007-12-01

    Nanoparticles and colloids are important intermediaries in the fate, transport and bioavailability of particle reactive trace metals and radionuclides in aquatic environments. However, the interaction between nanoparticles and natural organic matter (NOM) and how the quality and quantity of NOM affect the mobility and environmental behavior of trace elements remain poorly understood. Controlled laboratory experiments have been conducted to examine the role of NOM in governing the partitioning of Th(IV) and Pa(IV, V) between truly dissolved and different sized colloidal phases. Radiotracers, model NOM, including humic substances (HS) and exopolymeric acid polysaccharides (EPS), and ultrafiltration were used in the partitioning experiments of Th and Pa between the <1 kDa, 1-10 kDa, 10-100 kDa, 100 kDa-0.4μm and >0.4 μm fractions, thus allowing the calculation of distribution coefficients between particle (Kd) or colloid (Kc) and solution phases. Our results show that in both seawater and 0.7 M NaClO4 solution, Th(IV) has a higher distribution coefficient (Kd) between dissolved and particulate phases (with a logKd of 7.03) compared to Pa(IV, V) with a logKd of 6.05. Within the <0.4 μm dissolved phase, Th(IV) and Pa(IV, V) were mostly partitioned in the >1 kDa colloidal phase resulting in a logKc value of 6.08 and 5.70, respectively, for Th(IV) and Pa(IV,V). On average, about 4% of Th(IV) was measured in the <1 kDa fraction, but this fraction was up to 42% for Pa(IV, V). In the presence of HS and EPS (0.6 and 0.9 mg C/L) , however, the fraction partitioned in the <1 kDa become virtually the same (2-3%) for both Th(IV) and Pa(IV, V). The logKc value for Th(IV) and Pa(IV, V) was 7.05 and 7.06, respectively, in the presence of HS, and was 6.81 and 7.02 in the presence of EPS. While the partitioning of Th(IV) remained similar regardless of treatments, the change in the partitioning of Pa(IV, V) between dissolved and nanoparticles or macromolecules in the >1 kDa fraction

  20. Affective and Normative Commitment to Organization, Supervisor, and Coworkers: Do Collectivist Values Matter?

    ERIC Educational Resources Information Center

    Wasti, S. Arzu; Can, Ozge

    2008-01-01

    Employees' commitment to their organization is increasingly recognized as comprising of different bases (affect-, obligation-, or cost-based) and different foci (e.g., supervisor, coworkers). Two studies investigated affective and normative commitment to the organization, supervisor and coworkers in the Turkish context. The results of Study 1…

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

    USGS Publications Warehouse

    MacCoy, Dorene E.; Domagalski, Joseph L.

    1999-01-01

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

  2. Molecular size of aquatic humic substances

    USGS Publications Warehouse

    Thurman, E.M.; Wershaw, R. L.; Malcolm, R.L.; Pinckney, D.J.

    1982-01-01

    Aquatic humic substances, which account for 30 to 50% of the organic carbon in water, are a principal component of aquatic organic matter. The molecular size of aquatic humic substances, determined by small-angle X-ray scattering, varies from 4.7 to 33 A?? in their radius of gyration, corresponding to a molecular weight range of 500 to greater than 10,000. The aquatic fulvic acid fraction contains substances with molecular weights ranging from 500 to 2000 and is monodisperse, whereas the aquatic humic acid fraction contains substances with molecular weights ranging from 1000 to greater than 10,000 and is generally polydisperse. ?? 1982.

  3. Neurology of Affective Prosody and Its Functional-Anatomic Organization in Right Hemisphere

    ERIC Educational Resources Information Center

    Ross, Elliott D.; Monnot, Marilee

    2008-01-01

    Unlike the aphasic syndromes, the organization of affective prosody in brain has remained controversial because affective-prosodic deficits may occur after left or right brain damage. However, different patterns of deficits are observed following left and right brain damage that suggest affective prosody is a dominant and lateralized function of…

  4. Fabrication of nano-mosquitocides using chitosan from crab shells: Impact on non-target organisms in the aquatic environment.

    PubMed

    Murugan, Kadarkarai; Anitha, Jaganathan; Dinesh, Devakumar; Suresh, Udaiyan; Rajaganesh, Rajapandian; Chandramohan, Balamurugan; Subramaniam, Jayapal; Paulpandi, Manickam; Vadivalagan, Chitravel; Amuthavalli, Pandiyan; Wang, Lan; Hwang, Jiang-Shiou; Wei, Hui; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Kumar, Suresh; Pugazhendy, Kannaiyan; Higuchi, Akon; Nicoletti, Marcello; Benelli, Giovanni

    2016-10-01

    Mosquitoes are arthropods of huge medical and veterinary relevance, since they vector pathogens and parasites of public health importance, including malaria, dengue and Zika virus. Currently, nanotechnology is considered a potential eco-friendly approach in mosquito control research. We proposed a novel method of biofabrication of silver nanoparticles (AgNP) using chitosan (Ch) from crab shells. Ch-AgNP nanocomposite was characterized by UV-vis spectroscopy, FTIR, SEM, EDX and XRD. Ch-AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi obtaining LC50 ranging from 3.18 ppm (I) to 6.54 ppm (pupae). The antibacterial properties of Ch-AgNP were proved against Bacillus subtilis, Klebsiella pneumoniae and Salmonella typhi, while no growth inhibition was reported in assays conducted on Proteus vulgaris. Concerning non-target effects, in standard laboratory considtions the predation efficiency of Danio rerio zebrafishes was 68.8% and 61.6% against I and II instar larvae of A. stephensi, respectively. In a Ch-AgNP-contaminated environment, fish predation was boosted to 89.5% and 77.3%, respectively. Quantitative analysis of antioxidant enzymes SOD, CAT and LPO from hepatopancreas of fresh water crabs Paratelphusa hydrodromous exposed for 16 days to a Ch-AgNP-contaminated aquatic environment were conducted. Notably, deleterious effects of Ch-AgNP contaminating aquatic enviroment on the non-target crab P. hydrodromous were observed, particularly when doses higher than 8-10ppm are tested. Overall, this research highlights the potential of Ch-AGNP for the development of newer control tools against young instar populations of malaria mosquitoes, also highlighting some risks concerned the employ of nanoparticles in aquatic environments.

  5. Aquatic Sediments.

    ERIC Educational Resources Information Center

    Sanville, W. D.; And Others

    1978-01-01

    Presents a literature review of aquatic sediments and its effect upon water quality, covering publications of 1976-77. This review includes: (1) sediment water interchange; (2) chemical and physical characterization; and (3) heavy water in sediments. A list of 129 references is also presented. (HM)

  6. Application of Bayesian belief net in modelling the origin and effects of terrigenous dissolved organic matter in a boreal aquatic ecosystem

    NASA Astrophysics Data System (ADS)

    Rahikainen, Mika; Hoikkala, Laura; Soinne, Helena

    2013-04-01

    Bayesian belief nets (BBN) are capable of developing holistic understanding of the origin, transportation, and effects of dissolved organic matter (DOM) in ecosystems. The role of riverine DOM, transporting carbon and macronutrients N and P into lakes and coastal areas, has been largely neglected in research about processes influencing aquatic ecosystem functions although dissolved organic matter provides a significant nutrient source for primary producers in aquatic environments. This neglect has also contributed to the environmental policies which are focused in the control of inorganic N and P load. It is of great social and economic interest to gain improved knowledge of whether the currently applied policy instruments act in synchrony in mitigating eutrophication caused by N and P versus DOM load. DOM is a complex mixture of compounds that are poorly characterized. DOM export is strongly regulated by land use (urban, forest, agricultural land, peat land), in addition to soil type and soil organic carbon concentration. Furthermore, the composition of DOM varies according to its origin. The fate and effects of DOM loads in the fresh water and coastal environments depend, for example, on their biodegradability. Degradation kinetics again depends on the interactions between composition of the DOM pool and the receiving environment. Impact studies of dissolved organic matter pose a complicated environmental impact assessment challenge for science. There exists strategic uncertainty in the science about the causal dependencies and about the quality of knowledge related to DOM. There is a clear need for systematization in the approach as uncertainty is typically high about many key processes. A cross-sectorial, integrative analysis will aid in focusing on the most relevant issues. A holistic and unambiguous analysis will provide support for policy-decisions and management by indicating which outcome is more probable than another. The task requires coupling complex

  7. Drugs affecting prelamin A processing: Effects on heterochromatin organization

    SciTech Connect

    Mattioli, Elisabetta; Columbaro, Marta; Capanni, Cristina; Santi, Spartaco; D'Apice, M. Rosaria; Novelli, Giuseppe; Riccio, Massimo; Squarzoni, Stefano; Lattanzi, Giovanna

    2008-02-01

    Increasing interest in drugs acting on prelamin A has derived from the finding of prelamin A involvement in severe laminopathies. Amelioration of the nuclear morphology by inhibitors of prelamin A farnesylation has been widely reported in progeroid laminopathies. We investigated the effects on chromatin organization of two drugs inhibiting prelamin A processing by an ultrastructural and biochemical approach. The farnesyltransferase inhibitor FTI-277 and the non-peptidomimetic drug N-acetyl-S-farnesyl-L-cysteine methylester (AFCMe) were administered to cultured control human fibroblasts for 6 or 18 h. FTI-277 interferes with protein farnesylation causing accumulation of non-farnesylated prelamin A, while AFCMe impairs the last cleavage of the lamin A precursor and is expected to accumulate farnesylated prelamin A. FTI-277 caused redistribution of heterochromatin domains at the nuclear interior, while AFCMe caused loss of heterochromatin domains, increase of nuclear size and nuclear lamina thickening. At the biochemical level, heterochromatin-associated proteins and LAP2{alpha} were clustered at the nuclear interior following FTI-277 treatment, while they were unevenly distributed or absent in AFCMe-treated nuclei. The reported effects show that chromatin is an immediate target of FTI-277 and AFCMe and that dramatic remodeling of chromatin domains occurs following treatment with the drugs. These effects appear to depend, at least in part, on the accumulation of prelamin A forms, since impairment of prelamin A accumulation, here obtained by 5-azadeoxycytidine treatment, abolishes the chromatin effects. These results may be used to evaluate downstream effects of FTIs or other prelamin A inhibitors potentially useful for the therapy of laminopathies.

  8. Ultraviolet-B radiation mobilizes uranium from uranium-dissolved organic carbon complexes in aquatic systems, demonstrated by asymmetrical flow field-flow fractionation.

    PubMed

    Nehete, Sachin Vilas; Christensen, Terje; Salbu, Brit; Teien, Hans-Christian

    2017-03-21

    Humic substances have a tendency to form complexes with metal ions in aquatic medium, impacting the metal mobility, decreasing bioavailability and toxicity. Ultraviolet-B (UV-B) radiation exposure degrades the humic substance, changes their molecular weight distribution and their metal binding capacity in aquatic medium. In this study, we experimented the effect of UV-B radiation on the uranium complexed with fulvic acids and humic acids in a soft water system at different pH, uranium concentrations and radiant exposure. The concentration and distribution of uranium in a complexed form were investigated by asymmetrical flow field-flow fractionation coupled to multi detection technique (AsFlFFF-UV-ICP-MS). The major concentration of uranium present in complexes was primarily associated with average and higher molecular weight fulvic and humic acids components. The concentration of uranium in a complexed form increased with increasing fulvic and humic acid concentrations as well as pH of the solution. The higher molecular weight fraction of uranium was degraded due to the UV-B exposure, transforming about 50% of the uranium-dissolved organic carbon complexes into low molecular weight uranium species in complex form with organic ligands and/or free form. The result also suggests AsFlFFF-UV-ICP-MS to be an important separation and detection technique for understanding the interaction of radionuclides with dissolved organic matter, tracking size distribution changes during degradation of organic complexes for understanding mobility, bioavailability and ecosystem transfer of radionuclides as well as metals.

  9. Statistically validated QSARs, based on theoretical descriptors, for modeling aquatic toxicity of organic chemicals in Pimephales promelas (fathead minnow).

    PubMed

    Papa, Ester; Villa, Fulvio; Gramatica, Paola

    2005-01-01

    The use of Quantitative Structure-Activity Relationships in assessing the potential negative effects of chemicals plays an important role in ecotoxicology. (LC50)(96h) in Pimephales promelas (Duluth database) is widely modeled as an aquatic toxicity end-point. The object of this study was to compare different molecular descriptors in the development of new statistically validated QSAR models to predict the aquatic toxicity of chemicals classified according to their MOA and in a unique general model. The applied multiple linear regression approach (ordinary least squares) is based on theoretical molecular descriptor variety (1D, 2D, and 3D, from DRAGON package, and some calculated logP). The best combination of modeling descriptors was selected by the Genetic Algorithm-Variable Subset Selection procedure. The robustness and the predictive performance of the proposed models was verified using both internal (cross-validation by LOO, bootstrap, Y-scrambling) and external statistical validations (by splitting the original data set into training and validation sets by Kohonen-artificial neural networks (K-ANN)). The model applicability domain (AD) was checked by the leverage approach to verify prediction reliability.

  10. Organic waste compounds in streams: Occurrence and aquatic toxicity in different stream compartments, flow regimes, and land uses in southeast Wisconsin, 2006–9

    USGS Publications Warehouse

    Baldwin, Austin K.; Corsi, Steven R.; Richards, Kevin D.; Geis, Steven W.; Magruder, Christopher

    2013-01-01

    An assessment of organic chemicals and aquatic toxicity in streams located near Milwaukee, Wisconsin, indicated high potential for adverse impacts on aquatic organisms that could be related to organic waste compounds (OWCs). OWCs used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewage overflows, among other sources. Many of these compounds are toxic at elevated concentrations and (or) known to have endocrine-disrupting potential, and often they occur as complex mixtures. There is still much to be learned about the chronic exposure effects of these compounds on aquatic populations. During 2006–9, the U.S. Geological Survey, in cooperation with the Milwaukee Metropolitan Sewerage District (MMSD), conducted a study to determine the occurrence and potential toxicity of OWCs in different stream compartments and flow regimes for streams in the Milwaukee area. Samples were collected at 17 sites and analyzed for a suite of 69 OWCs. Three types of stream compartments were represented: water column, streambed pore water, and streambed sediment. Water-column samples were subdivided by flow regime into stormflow and base-flow samples. One or more compounds were detected in all 196 samples collected, and 64 of the 69 compounds were detected at least once. Base-flow samples had the lowest detection rates, with a median of 12 compounds detected per sample. Median detection rates for stormflow, pore-water, and sediment samples were more than double that of base-flow samples. Compounds with the highest detection rates include polycyclic aromatic hydrocarbons (PAHs), insecticides, herbicides, and dyes/pigments. Elevated occurrence and concentrations of some compounds were detected in samples from urban sites, as compared with more rural sites, especially during stormflow conditions. These include the PAHs and the domestic waste

  11. Comparison of organic matter composition in agricultural versus forest affected headwaters with special emphasis on organic nitrogen.

    PubMed

    Heinz, Marlen; Graeber, Daniel; Zak, Dominik; Zwirnmann, Elke; Gelbrecht, Joerg; Pusch, Martin T

    2015-02-17

    Agricultural management practices promote organic matter (OM) turnover and thus alter both the processing of dissolved organic matter (DOM) in soils and presumably also the export of DOM to headwater streams, which intimately connect the terrestrial with the aquatic environment. Size-exclusion chromatography, in combination with absorbance and emission matrix fluorometry, was applied to assess how agricultural land use alters the amount and composition of DOM, as well as dissolved organic nitrogen (DON) forms in headwater streams, including temporal variations, in a temperate region of NE Germany. By comparing six agriculturally and six forest-impacted headwater streams, we demonstrated that agriculture promotes increased DOC and DON concentrations, entailing an even more pronounced effect on DON. The major part of DOC and DON in agricultural and forest reference streams is exported in the form of humic-like material with high molecular weight, which indicates terrestrial, i.e., allochthonous sources. As an obvious difference in agricultural streams, the contribution of DOC and particularly DON occurring in the form of nonhumic high-molecular-weight, presumably proteinous material is clearly elevated. Altogether, DOM in agricultural headwaters is mainly complex-soil-derived and aromatic material with a low C:N ratio, which is more microbial processed than its counterpart from forest reference catchments. Our results emphasize the importance of agricultural land use on DOM loss from soils and identify agricultural soils as important DOC and particularly DON sources to headwater streams.

  12. Continuous measurement of oxygen tensions in the air-breathing organ of Pacific tarpon (Megalops cyprinoides) in relation to aquatic hypoxia and exercise.

    PubMed

    Seymour, Roger S; Farrell, Anthony P; Christian, Keith; Clark, Timothy D; Bennett, Michael B; Wells, Rufus M G; Baldwin, John

    2007-07-01

    The Pacific tarpon is an elopomorph teleost fish with an air-breathing organ (ABO) derived from a physostomous gas bladder. Oxygen partial pressure (PO(2)) in the ABO was measured on juveniles (238 g) with fiber-optic sensors during exposure to selected aquatic PO(2) and swimming speeds. At slow speed (0.65 BL s(-1)), progressive aquatic hypoxia triggered the first breath at a mean PO(2) of 8.3 kPa. Below this, opercular movements declined sharply and visibly ceased in most fish below 6 kPa. At aquatic PO(2) of 6.1 kPa and swimming slowly, mean air-breathing frequency was 0.73 min(-1), ABO PO(2) was 10.9 kPa, breath volume was 23.8 ml kg(-1), rate of oxygen uptake from the ABO was 1.19 ml kg(-1) min(-1), and oxygen uptake per breath was 2.32 ml kg(-1). At the fastest experimental speed (2.4 BL s(-1)) at 6.1 kPa, ABO oxygen uptake increased to about 1.90 ml kg(-1) min(-1), through a variable combination of breathing frequency and oxygen uptake per breath. In normoxic water, tarpon rarely breathed air and apparently closed down ABO perfusion, indicated by a drop in ABO oxygen uptake rate to about 1% of that in hypoxic water. This occurred at a wide range of ABO PO(2) (1.7-26.4 kPa), suggesting that oxygen level in the ABO was not regulated by intrinsic receptors.

  13. Laboratory evaluation of aqueous leaf extract of Tephrosia vogelii against larvae of Aedes albopictus (Diptera: Culicidae) and non-target aquatic organisms.

    PubMed

    Li, Weisheng; Huang, Congling; Wang, Kun; Fu, Jiantao; Cheng, Dongmei; Zhang, Zhixiang

    2015-06-01

    Mosquito control using insecticides has been the most successful intervention known to reduce malaria prevalence or incidence. However, vector control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. In this research, the leaf aqueous leachate of Tephrosia vogelii was evaluated for its toxicity against larvae of the most invasive mosquito worldwide, Aedes albopictus (Diptera: Culicidae), and toward adults of the water flea, Daphnia magna (Cladocera: Crustacea) and Oreochromis niloticus, two non-target aquatic organisms that share the same ecological niche of A. albopictus. The leaf aqueous leachate of T. vogelii was evaluated against fourth-instar larvae, non-blood fed 3-5 days old laboratory strains of A. albopictus under laboratory condition. In addition, the objective of the present work was to study the environmental safety evaluation for aquatic ecosystem. Mortality was then recorded after 7d exposure. The leaf aqueous leachate of T. vogelii showed high mosquitocidal activity against larvae of A. albopictus, with a LC50=1.18μg/mL. However, it had a remarkable acute toxicity also toward adults of the non-target arthropod D. magna, with a LC50=0.47μg/L and O. niloticus with a LC50=5.31μg/L. The present findings have important implications in the practical control of mosquito larvae in the aquatic ecosystem, as the medicinal plants studied are commonly available in large quantities. The extract could be used in stagnant water bodies for the control of mosquitoes acting as vector for many communicable diseases.

  14. Project WILD Aquatic K-12 Curriculum and Activity Guide

    ERIC Educational Resources Information Center

    Council for Environmental Education, 2011

    2011-01-01

    The "Project WILD Aquatic K-12 Curriculum and Activity Guide" emphasizes aquatic wildlife and aquatic ecosystems. It is organized in topic units and is based on the Project WILD conceptual framework. Because these activities are designed for integration into existing courses of study, instructors may use one or many Project WILD Aquatic activities…

  15. One-pot biogenic fabrication of silver nanocrystals using Quisqualis indica: Effectiveness on malaria and Zika virus mosquito vectors, and impact on non-target aquatic organisms.

    PubMed

    Govindarajan, Marimuthu; Vijayan, Periasamy; Kadaikunnan, Shine; Alharbi, Naiyf S; Benelli, Giovanni

    2016-09-01

    Currently, mosquito vector control is facing a number of key challenges, including the rapid development of resistance to synthetic pesticides and the recent spread of aggressive arbovirus outbreaks. The biosynthesis of silver nanoparticles (AgNPs) is currently considered an environmental friendly alternative to the employ of pyrethroids, carbamates and microbial agents (e.g. Bacillus thuringiensis var. israelensis), since AgNPs are easy to produce, effective and stable in the aquatic environment. However, their biophysical features showed wide variations according to the botanical agent using for the green synthesis, outlining the importance of screening local floral resources used as reducing and stabilizing agents. In this study, we focused on the biophysical properties and the mosquitocidal action of Quisqualis indica-fabricated AgNPs. AgNPs were characterized using spectroscopic (UV, FTIR, XRD) and microscopic (AFM, SEM, TEM and EDX) techniques. AFM, SEM and TEM confirmed the synthesis of poly-dispersed AgNPs with spherical shape and size ranging from 1 to 30nm. XRD shed light on the crystalline structure of these AgNPs. The acute toxicity of Quisqualis indica extract and AgNPs was evaluated against malaria, arbovirus, and filariasis vectors, Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus, as well as on three important non-target aquatic organisms. The Q. indica leaf extract showed moderate larvicidal effectiveness on Cx. quinquefasciatus (LC50=220.42), Ae. aegypti (LC50=203.63) and An. stephensi (LC50=185.98). Q. indica-fabricated AgNPs showed high toxicity against Cx. quinquefasciatus (LC50=14.63), Ae. aegypti (LC50=13.55) and An. stephensi (LC50=12.52), respectively. Notably, Q. indica-synthesized AgNPs were moderately toxic to non-target aquatic mosquito predators Anisops bouvieri (LC50=653.05μg/mL), Diplonychus indicus (LC50=860.94μg/mL) and Gambusia affinis (LC50=2183.16μg/mL), if compared to the targeted mosquitoes. Overall, the

  16. Tritium in the aquatic environment

    SciTech Connect

    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.

  17. Proposed Release Guides to Protect Aquatic Biota

    SciTech Connect

    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.

  18. Effects of contaminants on aquatic organisms in the Peace, Athabasca and Slave river basins. Northern River Basins Study synthesis report number 2

    SciTech Connect

    Carey, J.H.; Cordeiro, O.T.

    1997-01-01

    This report summarizes the activities of the Contaminants Component of the Northern River Basins Study to address the following questions: How the aquatic ecosystems in the Peace, Athabasca, and Slave river basins been affected by exposure to toxic compounds; and what long-term monitoring programs and predictive models are required to provide ongoing assessment of the state of those ecosystems. Research is described in four project areas: A basin-wide survey of biochemical responses to organochlorines and other contaminants in major fish species; a basin-wide survey of the toxicity in bottom and suspended sediments; an assessment of the utility of semi-permeable membrane devices as potential substitutes for wild fish in a long-term monitoring program; and assessment of the feasibility of using small, locally resident fish species as alternates to large adult fish in a long-term biological effects monitoring program.

  19. Watershed geomorphology modifies the temperature sensitivity of aquatic ecosystem metabolism

    NASA Astrophysics Data System (ADS)

    Jankowski, K. J.; Schindler, D.

    2015-12-01

    How carbon cycles are regulated by temperature remains a substantial uncertainty in our understanding of how watersheds will respond to ongoing climate change. Aquatic ecosystems are significant components of carbon flux to the atmosphere and ocean, yet we have limited understanding of how changing thermal regimes will alter rates of ecosystem metabolic processes, and, therefore, aquatic contributions to carbon cycles at watershed to global scales. Watershed geomorphology controls the landscape-scale distribution of organic material that can form the metabolic base of aquatic ecosystems, which will likely affect the temperature sensitivity of aquatic ecosystem metabolism. Across 23 streams in a boreal river basin, we estimated how temperature sensitivity of ecosystem respiration (ER), an important component of the aquatic C cycle, varied among streams with different watershed characteristics. We found that geomorphic conditions imposed strong ultimate controls on temperature sensitivity: ER in streams draining flat watersheds was much more sensitive to temperature than streams draining steeper watersheds. Further, we show that the link between watershed geomorphology and temperature sensitivity was related to changes in the quality of carbon substrates across the gradient in watershed slope. These results suggest that geomorphic conditions will ultimately control how carbon processing responds to warming climate, thereby affecting carbon transport and storage, and likely food web responses, in river networks.

  20. Dissolved Organic In Natural and Polluted Waters: Methodology and Results of Running Control of Chemical Oxygen Demand (cod) For The Inland and Marine Aquatic System

    NASA Astrophysics Data System (ADS)

    Melentyev, K. V.; Worontsov, A. M.

    Current control of dissolved organic matter in natural and waste waters is the definition traditionally of chemical oxygen demand (COD) -- one of the basic parameters of quality of water. According to the International Standard (ISO 6060), it requires not less than one hour, while in many cases the operative information about amount of dissolved organic matter in aquatic environments have importance for prevention of an emergency. The standard method is applicable to waters with meaning of COD above 30 mg O2/l and, as the chloride ion prevents, it could be difficult for assessment of organic matter in sea water. Besides it is based on dichromate oxidation of the sum of organic substances in strong acid conditions at the presence of silver and mercury, that resulted in formation toxic pollutants. Till now attempts of automation of the COD definition in aquatic system were limited, basically, to duplication of the technology submitted the above standard (automatic COD analyzers "SERES Co."-- France, or "Tsvet Co." - Russia). The system of ozone-chemiluminescence automatic control of organic matter in water (CS COD) is offered and designed. Its based on the ozone oxidation of these substances in flowing water system and measurement arising from luminescent effects. CS COD works in real time. An instrument uses for reaction the atmospheric air, doesn't require fill of reagents and doesn't make new toxic pollutants. The system was tested in laboratory, and biochemical control of organic matter in water samples gathered from the river Neva and other polluted inland water areas and basins in St. Petersburg region was fulfilled (distilled water was used as "zero" media). The results of systematization of these measurements are presented. The new special ozone generator and flowing reactor for real-time running control of different waters in natural conditions were developed, and several series of large - scale field experiments onboard research ship were provided

  1. Composition of whole and water extractable organic matter of cattle manure affected by management practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic matter (OM) is a major component of animal manure. In this chapter, we present two case studies on the multiple spectral features of whole and water extractable organic matter (WEOM) of cattle (beef and dairy) manure affected by differing management practices. Using wet chemistry and Fourie...

  2. Selective serotonin reuptake inhibitors and β-blocker transformation products may not pose a significant risk of toxicity to aquatic organisms in wastewater effluent-dominated receiving waters.

    PubMed

    Brown, Alistair K; Challis, Jonathan K; Wong, Charles S; Hanson, Mark L

    2015-10-01

    A probabilistic ecological risk assessment was conducted for the transformation products (TPs) of 3 β-blockers (atenolol, metoprolol, and propranolol) and 5 selective serotonin reuptake inhibitors (SSRIs; citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline) to assess potential threats to aquatic organisms in effluent-dominated surface waters. To this end, the pharmacokinetic literature, the University of Minnesota's Biocatalysis/Biodegradation Database Pathway Prediction System aerobic microbial degradation software, and photolysis literature pertaining to β-blockers and SSRIs were used to determine their most likely TPs formed via human metabolism, aerobic biodegradation, and photolysis, respectively. Monitoring data from North American and European surface waters receiving human wastewater inputs were the basis of the exposure characterizations of the parent compounds and the TPs, where available. In most cases, where monitoring data for TPs did not exist, we assumed a conservative 1:1 parent-to-TP production ratio (i.e., 100% of parent converted). The US Environmental Protection Agency (USEPA)'s EPISuite and ECOSAR v1.11 software were used to estimate acute and chronic toxicities to aquatic organisms. Hazard quotients, which were calculated using the 95(th) percentile of the exposure distributions, ranged from 10(-11) to 10(-3) (i.e., all significantly less than 1). Based on these results, the TPs of interest would be expected to pose little to no environmental risk in surface waters receiving wastewater inputs. Overall, we recommend developing analytical methods that can isolate and quantify human metabolites and TPs at environmentally relevant concentrations to confirm these predictions. Further, we recommend identifying the major species of TPs from classes of pharmaceuticals that could elicit toxic effects via specific modes of action (e.g., norfluoxetine via the serotonin 5-hydroxytryptamine [5-HT]1A receptors) and conducting aquatic toxicity

  3. Toxicity of ZnO nanoparticles, ZnO bulk, and ZnCl₂ on earthworms in a spiked natural soil and toxicological effects of leachates on aquatic organisms.

    PubMed

    García-Gómez, C; Babin, M; Obrador, A; Álvarez, J M; Fernández, M D

    2014-11-01

    The present study assessed the uptake and toxicity of ZnO nanoparticles (NPs), ZnO bulk, and ZnCl₂ salt in earthworms in spiked agricultural soils. In addition, the toxicity of aqueous extracts to Daphnia magna and Chlorella vulgaris was analyzed to determine the risk of these soils to the aquatic compartment. We then investigated the distribution of Zn in soil fractions to interpret the nature of toxicity. Neither mortality nor differences in earthworm body weight were observed compared with the control. The most sensitive end point was reproduction. ZnCl₂ was notably toxic in eliminating the production of cocoons. The effects induced by ZnO-NPs and bulk ZnO on fecundity were similar and lower than those of the salt. In contrast to ZnO bulk, ZnO-NPs adversely affected fertility. The internal concentrations of Zn in earthworms in the NP group were greater than those in the salt and bulk groups, although bioconcentration factors were consistently <1. No relationship was found between toxicity and internal Zn amounts in earthworms. The results from the sequential extraction of soil showed that ZnCl₂ displayed the highest availability compared with both ZnO. Zn distribution was consistent with the greatest toxicity showed by the salt but not with Zn body concentrations. The soil extracts from both ZnO-NPs and bulk ZnO did not show effects on aquatic organisms (Daphnia and algae) after short-term exposure. However, ZnCl₂ extracts (total and 0.45-μm filtered) were toxic to Daphnia.

  4. Effects of Tidal Turbine Noise on Fish Task 2.1.3.2: Effects on Aquatic Organisms: Acoustics/Noise - Fiscal Year 2011 - Progress Report - Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect

    Halvorsen, Michele B.; Carlson, Thomas J.; Copping, Andrea E.

    2011-09-30

    Naturally spawning stocks of Chinook salmon (Oncorhynchus tshawytscha) that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/ Chinook/CKPUG.cfm). Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study (Effects on Aquatic Organisms, Subtask 2.1.3.2: Acoustics) was performed during FY 2011 to determine if noise generated by a 6-m-diameter open-hydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. After they were exposed to simulated tidal turbine noise, the hearing of juvenile Chinook salmon was measured and necropsies performed to check for tissue damage. Experimental groups were (1) noise exposed, (2) control (the same handling as treatment fish but without exposure to tidal turbine noise), and (3) baseline (never handled). Preliminary results indicate that low levels of tissue damage may have occurred but that there were no effects of noise exposure on the auditory systems of the test fish.

  5. Pesticide Toxicity Index--a tool for assessing potential toxicity of pesticide mixtures to freshwater aquatic organisms.

    PubMed

    Nowell, Lisa H; Norman, Julia E; Moran, Patrick W; Martin, Jeffrey D; Stone, Wesley W

    2014-04-01

    Pesticide mixtures are common in streams with agricultural or urban influence in the watershed. The Pesticide Toxicity Index (PTI) is a screening tool to assess potential aquatic toxicity of complex pesticide mixtures by combining measures of pesticide exposure and acute toxicity in an additive toxic-unit model. The PTI is determined separately for fish, cladocerans, and benthic invertebrates. This study expands the number of pesticides and degradates included in previous editions of the PTI from 124 to 492 pesticides and degradates, and includes two types of PTI for use in different applications, depending on study objectives. The Median-PTI was calculated from median toxicity values for individual pesticides, so is robust to outliers and is appropriate for comparing relative potential toxicity among samples, sites, or pesticides. The Sensitive-PTI uses the 5th percentile of available toxicity values, so is a more sensitive screening-level indicator of potential toxicity. PTI predictions of toxicity in environmental samples were tested using data aggregated from published field studies that measured pesticide concentrations and toxicity to Ceriodaphnia dubia in ambient stream water. C. dubia survival was reduced to ≤50% of controls in 44% of samples with Median-PTI values of 0.1-1, and to 0% in 96% of samples with Median-PTI values >1. The PTI is a relative, but quantitative, indicator of potential toxicity that can be used to evaluate relationships between pesticide exposure and biological condition.

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

    USGS Publications Warehouse

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

    2017-01-01

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

  7. An integrated approach to model the biomagnification of organic pollutants in aquatic food webs of the Yangtze Three Gorges Reservoir ecosystem using adapted pollution scenarios.

    PubMed

    Scholz-Starke, Björn; Ottermanns, Richard; Rings, Ursula; Floehr, Tilman; Hollert, Henner; Hou, Junli; Li, Bo; Wu, Ling Ling; Yuan, Xingzhong; Strauch, Katrin; Wei, Hu; Norra, Stefan; Holbach, Andreas; Westrich, Bernhard; Schäffer, Andreas; Roß-Nickoll, Martina

    2013-10-01

    The impounding of the Three Gorges Reservoir (TGR) at the Yangtze River caused large flooding of urban, industrial, and agricultural areas, and profound land use changes took place. Consequently, substantial amounts of organic and inorganic pollutants were released into the reservoir. Additionally, contaminants and nutrients are entering the reservoir by drift, drainage, and runoff from adjacent agricultural areas as well as from sewage of industry, aquacultures, and households. The main aim of the presented research project is a deeper understanding of the processes that determines the bioaccumulation and biomagnification of organic pollutants, i.e., mainly pesticides, in aquatic food webs under the newly developing conditions of the TGR. The project is part of the Yangtze-Hydro environmental program, financed by the German Ministry of Education and Science. In order to test combinations of environmental factors like nutrients and pollution, we use an integrated modeling approach to study the potential accumulation and biomagnification. We describe the integrative modeling approach and the consecutive adaption of the AQUATOX model, used as modeling framework for ecological risk assessment. As a starting point, pre-calibrated simulations were adapted to Yangtze-specific conditions (regionalization). Two exemplary food webs were developed by a thorough review of the pertinent literature. The first typical for the flowing conditions of the original Yangtze River and the Daning River near the city of Wushan, and the second for the stagnant reservoir characteristics of the aforementioned region that is marked by an intermediate between lake and large river communities of aquatic organisms. In close cooperation with German and Chinese partners of the Yangtze-Hydro Research Association, other site-specific parameters were estimated. The MINIBAT project contributed to the calibration of physicochemical and bathymetric parameters, and the TRANSMIC project delivered

  8. Microplastic in Aquatic Ecosystems.

    PubMed

    Ivleva, Natalia P; Wiesheu, Alexandra C; Niessner, Reinhard

    2017-02-06

    The contamination of marine and freshwater ecosystems with plastic, and especially with microplastic (MP), is a global ecological problem of increasing scientific concern. This has stimulated a great deal of research on the occurrence of MP, interaction of MP with chemical pollutants, the uptake of MP by aquatic organisms, and the resulting (negative) impact of MP. Herein, we review the major issues of MP in aquatic environments, with the principal aims 1) to characterize the methods applied for MP analysis (including sampling, processing, identification and quantification), indicate the most reliable techniques, and discuss the required further improvements; 2) to estimate the abundance of MP in marine/freshwater ecosystems and clarify the problems that hamper the comparability of such results; and 3) to summarize the existing literature on the uptake of MP by living organisms. Finally, we identify knowledge gaps, suggest possible strategies to assess environmental risks arising from MP, and discuss prospects to minimize MP abundance in aquatic ecosystems.

  9. Size distribution effects of cadmium tellurium quantum dots (CdS/CdTe) immunotoxicity on aquatic organisms.

    PubMed

    Bruneau, A; Fortier, M; Gagne, F; Gagnon, C; Turcotte, P; Tayabali, A; Davis, T L; Auffret, M; Fournier, M

    2013-03-01

    The increasing use of products derived from nanotechnology has raised concern about their potential toxicity to aquatic life. This study sought to examine the comparative immunotoxicity of capped cadmium sulphide/cadmium telluride (CdS/CdTe) quantum dots (QDs) and possible impact of particle/aggregate size on two bivalves (Mytilus edulis and Elliptio complanata) and a fish (Oncorhynchus mykiss). The QDs were dispersed in sterile water and fractionated using a series of micro/ultrafiltration membranes of decreasing pore size: 450 nm, 100 nm, 50 nm, 25 nm, 100 kDa (6.8 nm), 30 kDa (4.6 nm), 10 kDa (3.2 nm) and 1 kDa (1.5 nm). The total concentrations of cadmium and tellurium were determined for the filtered material and for that retained on the filters (retentate). The immunotoxicity was determined by measuring cell viability and phagocytosis. Results revealed that nanoparticles retained on the ultrafilters had a higher Cd/Te ratio compared to the permeate fraction (ratio of 5 and 2 respectively) which could indicate that the CdS core was not associated with the permeable fraction of Cd. Our results demonstrate that the toxicity of CdS/CdTe QDs was concentration and size dependent. Large CdS/CdTe QD aggregates (25 nm < size < 100 nm) reduced phagocytosis more than did smaller nanoparticles (<25 nm). Moreover, our results revealed that the different species responded differently to these fractions. Mytilus edulis hemocytes were less sensitive to CdS/CdTe QDs than the Oncorhynchus mykiss macrophage and Elliptio complanata hemocytes.

  10. Calibration of nylon organic chemical integrative samplers and sentinel samplers for quantitative measurement of pulsed aquatic exposures.

    PubMed

    Morrison, Shane A; Belden, Jason B

    2016-06-03

    Environmental exposures often occur through short, pulsed events; therefore, the ability to accurately measure these toxicologically-relevant concentrations is important. Three different integrative passive sampler configurations were evaluated under different flow and pulsed exposure conditions for the measurement of current-use pesticides (n=19), polyaromatic hydrocarbons (n=10), and personal care products (n=5) spanning a broad range of hydrophobicities (log Kow 1.5-7.6). Two modified POCIS-style samplers were investigated using macroporous nylon mesh membranes (35μm pores) and two different sorbent materials (i.e. Oasis HLB and Dowex Optipore L-493). A recently developed design, the Sentinel Sampler (ABS Materials), utilizing Osorb media enclosed within stainless steel mesh (145μm pores), was also investigated. Relatively high sampling rates (Rs) were achieved for all sampler configurations during the short eight-day exposure (4300-27mL/d). Under flow conditions, median Rs were approximately 5-10 times higher for POCIS-style samplers and 27 times higher for Sentinel Samplers, as compared to static conditions. The ability of samplers to rapidly measure hydrophobic contaminants may be a trade off with increased flow dependence. Analyte accumulation was integrative under pulsed and continuous exposures for POCIS-style samplers with mean difference between treatments of 11% and 33%; however, accumulation into Sentinel Samplers was more variable. Collectively, results show that reducing membrane limitations allows for rapid, integrative accumulation of a broad range of analytes even under pulsed exposures. As such, these sampler designs may be suitable for monitoring environmental substances that have short aquatic half-lives.

  11. Aquatic Nuisance Species Locator

    EPA Pesticide Factsheets

    Data in this map has been collected by the United States Geological Survey's Nonindigenous Aquatic Species program located in Gainesville, Florida (http://nas.er.usgs.gov/default.aspx). This dataset may have some inaccuracies and is only current to June 15, 2012. The species identified in this dataset are not inclusive of all aquatic nuisance species, but rather a subset identified to be at risk for transport by recreational activities such as boating and angling. Additionally, the locations where organisims have been identified are also not inclusive and should be treated as a guide. Organisms are limited to the following: American bullfrog, Asian clam, Asian shore crab, Asian tunicate, Australian spotted jellyfish, Chinese mitten crab, New Zealand mudsnail, Colonial sea squirt, Alewife, Bighead carp, Black carp, Flathead catfish, Grass carp, Green crab, Lionfish, Northern snakehead, Quagga mussel, Round Goby, Ruffe, Rusty crayfish, Sea lamprey, Silver carp, Spiny water flea, Veined rapa whelk, Zebra mussel

  12. Aquatic toxicology: past, present, and prospects.

    PubMed Central

    Pritchard, J B

    1993-01-01

    Aquatic organisms have played important roles as early warning and monitoring systems for pollutant burdens in our environment. However, they have significant potential to do even more, just as they have in basic biology where preparations like the squid axon have been essential tools in establishing physiological and biochemical mechanisms. This review provides a brief summary of the history of aquatic toxicology, focusing on the nature of aquatic contaminants, the levels of contamination in our waters, and the origins of these agents. It considers the features of the aquatic environment that determine the availability of xenobiotics to aquatic life and the fate of foreign chemicals within the organism. Finally, toxic effects are considered with primary emphasis on the potential of aquatic models to facilitate identification of the underlying mechanisms of toxicity. PMID:8354173

  13. INTEGRATED STATE-FEDERAL PARTNERSHIP FOR AQUATIC RESOURCE MONITORING

    EPA Science Inventory

    Fifteen federal agencies, 50 states, cities, counties, and 800-1000 volunteer organizations conduct aquatic resource monitoring in the United States. Most aquatic monitoring is project-specific focusing on individual locations or watersheds. The Clean Water Act requires states ...

  14. Effect of pesticides on microbial communities in container aquatic habitats.

    PubMed

    Muturi, Ephantus J; Donthu, Ravi Kiran; Fields, Christopher J; Moise, Imelda K; Kim, Chang-Hyun

    2017-03-16

    Container aquatic habitats support a specialized community of macroinvertebrates (e.g. mosquitoes) that feed on microbial communities associated with decaying organic matter. These aquatic habitats are often embedded within and around agricultural lands and are frequently exposed to pesticides. We used a microcosm approach to examine the single and combined effects of two herbicides (atrazine, glyphosate), and three insecticides (malathion, carbaryl, permethrin) on microbial communities of container aquatic habitats. MiSeq sequencing of the V4 region of both bacterial and archaeal 16S rRNA gene was used to characterize the microbial communities of indoor microcosms that were either exposed to each pesticide alone, a mix of herbicides, a mix of insecticides, or a mix of all five insecticides. Individual insecticides but not herbicides reduced the microbial diversity and richness and two insecticides, carbaryl and permethrin, also altered the microbial community structure. A mixture of herbicides had no effect on microbial diversity or structure but a mixture of insecticides or all five pesticides reduced microbial diversity and altered the community structure. These findings suggest that exposure of aquatic ecosystems to individual pesticides or their mixtures can disrupt aquatic microbial communities and there is need to decipher how these changes affect resident macroinvertebrate communities.

  15. Effect of pesticides on microbial communities in container aquatic habitats

    PubMed Central

    Muturi, Ephantus J.; Donthu, Ravi Kiran; Fields, Christopher J.; Moise, Imelda K.; Kim, Chang-Hyun

    2017-01-01

    Container aquatic habitats support a specialized community of macroinvertebrates (e.g. mosquitoes) that feed on microbial communities associated with decaying organic matter. These aquatic habitats are often embedded within and around agricultural lands and are frequently exposed to pesticides. We used a microcosm approach to examine the single and combined effects of two herbicides (atrazine, glyphosate), and three insecticides (malathion, carbaryl, permethrin) on microbial communities of container aquatic habitats. MiSeq sequencing of the V4 region of both bacterial and archaeal 16S rRNA gene was used to characterize the microbial communities of indoor microcosms that were either exposed to each pesticide alone, a mix of herbicides, a mix of insecticides, or a mix of all five insecticides. Individual insecticides but not herbicides reduced the microbial diversity and richness and two insecticides, carbaryl and permethrin, also altered the microbial community structure. A mixture of herbicides had no effect on microbial diversity or structure but a mixture of insecticides or all five pesticides reduced microbial diversity and altered the community structure. These findings suggest that exposure of aquatic ecosystems to individual pesticides or their mixtures can disrupt aquatic microbial communities and there is need to decipher how these changes affect resident macroinvertebrate communities. PMID:28300212

  16. Leveraging existing data for prioritization of the ecological risks of human and veterinary pharmaceuticals to aquatic organisms

    EPA Science Inventory

    Medicinal innovation has lead to the discovery and use of thousands of human and veterinary drugs. With this comes the potential for unintended effects on non-target organisms exposed to pharmaceuticals inevitably entering the environment. The impracticality of generating whole-o...

  17. Influence of salinity and organic nutrient concentration on survival and growth of Vibrio cholerae in aquatic microcosms.

    PubMed Central

    Singleton, F L; Attwell, R W; Jangi, M S; Colwell, R R

    1982-01-01

    Laboratory microcosms were employed to evaluate the influence of selected environmental parameters, organic nutrient concentration, and salinity on the growth and survival of a toxigenic strain of Vibrio cholerae LA4808. Over the range conditions tested, this strain of V. cholerae showed maximum response as determined by increased plate counts and direct microscopic counts in microcosms prepared with a chemically defined sea salts solution at a salinity of 25%, but with lower or higher salinity levels, the maximum population size declined. When added organic concentrations of less than 1,000 micrograms/liter were present, a marked salinity effect on the growth of V. cholerae was detected. However, at or above an organic nutrient concentration of 1,000 micrograms/liter, the need for an optimum salinity level was spared. From the results of this study, it is concluded that V. cholerae can grow under conditions of organic nutrient concentration and salinity typical of estuaries. Results obtained support the hypothesis that V. cholerae is an autochthonous member of the estuarine microbial community. PMID:6896621

  18. Key soil functional properties affected by soil organic matter - evidence from published literature

    NASA Astrophysics Data System (ADS)

    Murphy, Brian

    2015-07-01

    The effect of varying the amount of soil organic matter on a range of individual soil properties was investigated using a literature search of published information largely from Australia, but also included relevant information from overseas. Based on published pedotransfer functions, soil organic matter was shown to increase plant available water by 2 to 3 mm per 10 cm for each 1% increase in soil organic carbon, with the largest increases being associated with sandy soils. Aggregate stability increased with increasing soil organic carbon, with aggregate stability decreasing rapidly when soil organic carbon fell below 1.2 to 1.5 5%. Soil compactibility, friability and soil erodibility were favourably improved by increasing the levels of soil organic carbon. Nutrient cycling was a major function of soil organic matter. Substantial amounts of N, P and S become available to plants when the soil organic matter is mineralised. Soil organic matter also provides a food source for the microorganisms involved in the nutrient cycling of N, P, S and K. In soils with lower clay contents, and less active clays such as kaolinites, soil organic matter can supply a significant amount of the cation exchange capacity and buffering capacity against acidification. Soil organic matter can have a cation exchange capacity of 172 to 297 cmol(+)/kg. As the cation exchange capacity of soil organic matter varies with pH, the effectiveness of soil organic matter to contribute to cation exchange capacity below pH 5.5 is often minimal. Overall soil organic matter has the potential to affect a range of functional soil properties.

  19. Quantifying Water Flow within Aquatic Ecosystems Using Load Cell Sensors: A Profile of Currents Experienced by Coral Reef Organisms around Lizard Island, Great Barrier Reef, Australia

    PubMed Central

    Johansen, Jacob L.

    2014-01-01

    Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (<$150) to provide a detailed current velocity profile of the coral-reef system around Lizard Island (Great Barrier Reef, Australia) at a spatial and temporal scale relevant to the ecology of individual benthos and fish. The instrument uses load-cell sensors to provide a correlation between sensor output and ambient current velocity of 99%. Each instrument is able to continuously record current velocities to >500 cms−1 and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.). Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm−2 allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m), mid-slope (6 m) and deep-slope (9 m depth) of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: Currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms−1, while tidal currents rarely exceed 5.5 cms−1. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m) and frequency (0.54 to 0.20 Hz), emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats. PMID:24421878

  20. Quantifying water flow within aquatic ecosystems using load cell sensors: a profile of currents experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Johansen, Jacob L

    2014-01-01

    Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (<$150) to provide a detailed current velocity profile of the coral-reef system around Lizard Island (Great Barrier Reef, Australia) at a spatial and temporal scale relevant to the ecology of individual benthos and fish. The instrument uses load-cell sensors to provide a correlation between sensor output and ambient current velocity of 99%. Each instrument is able to continuously record current velocities to >500 cms⁻¹ and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.). Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm⁻² allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m), mid-slope (6 m) and deep-slope (9 m depth) of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms⁻¹, while tidal currents rarely exceed 5.5 cms⁻¹. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m) and frequency (0.54 to 0.20 Hz), emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats.

  1. A quantication of photoproduction of CO2 throughout the water column by degradation of terrigenous organic compounds present in the dissolved form for aquatic ecosystems of the boreal region in Quebec

    NASA Astrophysics Data System (ADS)

    Plouhinec, J.; Lucotte, M. M.; Ouellet, A.; Gelinas, Y.

    2010-12-01

    This study focuses on the quantity of CO2 produced by photodegradation in various pristine and disrupted water bodies. Photodegradation of dissolved organic matter (DOM) in the water column was evaluated in relation to two environmental factors e.g., the presence or absence of logging on the watershed and the contrast between natural lakes and hydroelectric reservoirs. Water samples were irradiated after filtration under 0,2µm, and subsequently analyzed for their CO2 production. Mean energy normalized for the spectral energy exposed to samples was determined to evaluate the photoreactivity of DOM under similar exposure conditions. In complement, organic matter samples had been concentrated via reverse osmosis. We then characterized the origin of DOM present in the water column with lignin biomarkers. Our results confirmed that the photomineralization increased significantly with DOM concentration. The daily photodegradation production was strikingly different in natural lakes and hydroelectric reservoirs. Average springtime and summertime production was evaluated at 5.45 ± 5.61 µmol.L-1.d-1 for lakes, compared to 14.21 ± 8.77 µmol.L-1.d-1 for boreal reservoirs. A similar comparison between ecosystems affected and unaffected by logging, also showed contrasting results for the photodegradation of DOM. Moreover, our lignin biomarkers increased significantly with CO2 generation. It thus appears that allochthonous organic matter strongly influences CO2 photoproduction. Finally, we evaluated the Photochemical Contribution to CO2 diffusive Fluxes (PCFCO2) between 14% and 32% depending on the degree of perturbation of the aquatic system.

  2. Importance of within-lake processes in affecting the dynamics of dissolved organic carbon and dissolved organic and inorganic nitrogen in an Adirondack forested lake/watershed

    NASA Astrophysics Data System (ADS)

    Kang, Phil-Goo; Mitchell, Myron J.; McHale, Patrick J.; Driscoll, Charles T.; Inamdar, Shreeram; Park, Ji-Hyung

    2016-05-01

    Lakes nested in forested watersheds play an important role in mediating the concentrations and fluxes of dissolved organic matter. We compared long-term patterns of concentrations and fluxes of dissolved organic carbon (DOC) and dissolved organic (DON) and inorganic nitrogen (DIN) in aquatic ecosystems of the Arbutus Lake watershed to evaluate how a lake nested in a forested watershed affects the sources (e.g., production) and sinks (e.g., retention) of DOC and DON in the Adirondack Mountains of New York, USA. We observed no significant long-term changes of DOC and DON in the lake outlet since 1983 and 1994, respectively. However, the temporal patterns of DOC and DON concentrations in the lake inlet showed significant seasonality such as increases during the vegetation-growing season along with notable decreases in the dormant season. A comparison of mass balances between inlet and outlet for the period from 2000 to 2009 suggested that the lake was a sink of DOC (mean of influx minus outflux: +1140 mol C ha-1 yr-1). In contrast, the difference of discharge-weighted DON concentrations (mean of inlet minus outlet: -1.0 µmol N L-1) between inlet and outlet was much smaller than the discharge-weighted DOC concentrations (average of inlet minus outlet: + 87 µmol C L-1). DON fluxes showed considerable variation among years (mean of influx minus outflux: +8 mol N ha-1 yr-1; range of differences: -15 to 27 mol N ha-1 yr-1). DON exhibited low percent retention ((influx-outflux)/influx) (mean: 6.9 %, range: -34.8 to +31.2) compared to DOC (mean: 30.1 %, range: +9.2 to +44.1). The resultant increase of DON within the lake was closely linked with a net decrease of DIN through monthly Pearson correlation analysis, suggesting the importance of biotic factors in mediating lake DON dynamics. Our results show different relative retentions of DOC compared with DON, along with a larger retention of DIN than DON, suggesting that DOC and DON might display substantially different

  3. Optical properties of natural dissolved organic matter (DOM) in aquatic ecosystems: Applications in ecosystem studies from headwater streams to the deep ocean. (Invited)

    NASA Astrophysics Data System (ADS)

    Jaffe, R.

    2010-12-01

    The study of natural dissolved organic material (DOM) contributes to the better understanding of ecosystem function as the carbon flux between environmental compartments represents an important linkage between terrestrial and aquatic ecosystems. Within freshwater and marine ecosystems, DOM typically represents the largest pool of detrital organic carbon and greatly exceeds the organic carbon present in living biomass. Thus, the sources and fate of DOM are important terms in carbon budgets. DOM can also influence ecosystem function by controlling microbial food webs, act as a means of nutrient transport, buffer pH and influence toxicity and bioavailability of pollutants, among others. DOM composition influences its ‘quality’ and thus its photo- and bio-reactivity, both of which exert a strong control of the diagenetic reworking of this carbon pool. However, the molecular composition of DOM is highly complex and diverse, and its characterization is a serious challenge to analytical chemists. In recent years, several novel analytical approaches to the characterization of DOM have evolved, including those that are highly structure specific and others that provide information on broader molecular characteristics. Whilst the former are usually expensive and time consuming, the latter, often based on optical properties measurements, feature high sample throughput at a reduced cost but at the expense of structural specificity. While both approaches are complementary under ideal conditions, the latter are best suited for studies involving large spatial and temporal scales. The analysis of DOM optical properties, in particular excitation emission matrix (EEM) fluorescence combined with parallel factor analysis (PARAFAC), has emerged as a practical tool for the broad characterization of DOM quality. This presentation will provide examples for the application of EEM-PARAFAC in assessing environmental dynamics of DOM on both spatial and temporal scales, and in both

  4. Minimal levels of ultraviolet light enhance the toxicity of TiO2 nanoparticles to two representative organisms of aquatic systems

    NASA Astrophysics Data System (ADS)

    Clemente, Z.; Castro, V. L.; Jonsson, C. M.; Fraceto, L. F.

    2014-08-01

    A number of studies have been published concerning the potential ecotoxicological risks of titanium dioxide nanoparticles (nano-TiO2), but the results still remain inconclusive. The characteristics of the diverse types of nano-TiO2 must be considered in order to establish experimental models to study their toxicity. TiO2 has important photocatalytic properties, and its photoactivation occurs in the ultraviolet (UV) range. The aim of this study was to investigate the toxicity of nano-TiO2 to indicators organisms of freshwater and saline aquatic systems, under different illumination conditions (visible light, with or without UV light). Daphnia similis and Artemia salina were co-exposed to a sublethal dose of UV light and different concentrations of nano-TiO2 in the form of anatase (TA) or an anatase/rutile mixture (TM). Both products were considered practically non-toxic under visible light to D. similis and A. salina (EC5048h > 100 mg/L). Exposure to nano-TiO2 under visible and UV light enhanced the toxicity of both products. In the case of D. similis, TM was more toxic than TA, showing values of EC5048h = 60.16 and 750.55 mg/L, respectively. A. salina was more sensitive than D. similis, with EC5048h = 4 mg/L for both products. Measurements were made of the growth rates of exposed organisms, together with biomarkers of oxidative stress and metabolism. The results showed that the effects of nano-TiO2 depended on the organism, exposure time, crystal phase, and illumination conditions, and emphasized the need for a full characterization of nanoparticles and their behavior when studying nanotoxicity.

  5. 5 CFR 5502.107 - Supplemental disclosure of financial interests in substantially affected organizations applicable...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... investigator, medical advisory investigator, associate investigator, or other subinvestigator in an NIH... with the NIH any financial interest in a substantially affected organization and the value thereof held... agency component, other than the NIH, or of the remainder of HHS who is either a public filer,...

  6. 5 CFR 5502.107 - Supplemental disclosure of financial interests in substantially affected organizations applicable...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... investigator, medical advisory investigator, associate investigator, or other subinvestigator in an NIH... with the NIH any financial interest in a substantially affected organization and the value thereof held... agency component, other than the NIH, or of the remainder of HHS who is either a public filer,...

  7. 5 CFR 5502.107 - Supplemental disclosure of financial interests in substantially affected organizations applicable...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... investigator, medical advisory investigator, associate investigator, or other subinvestigator in an NIH... with the NIH any financial interest in a substantially affected organization and the value thereof held... agency component, other than the NIH, or of the remainder of HHS who is either a public filer,...

  8. 5 CFR 5502.107 - Supplemental disclosure of financial interests in substantially affected organizations applicable...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... investigator, medical advisory investigator, associate investigator, or other subinvestigator in an NIH... with the NIH any financial interest in a substantially affected organization and the value thereof held... agency component, other than the NIH, or of the remainder of HHS who is either a public filer,...

  9. 29 CFR 401.10 - Labor organization engaged in an industry affecting commerce.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 2 2010-07-01 2010-07-01 false Labor organization engaged in an industry affecting commerce. 401.10 Section 401.10 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS, DEPARTMENT OF LABOR LABOR-MANAGEMENT STANDARDS MEANING OF TERMS USED IN THIS SUBCHAPTER § 401.10...

  10. Sorption interactions of organic compounds with soils affected by agricultural olive mill wastewater.

    PubMed

    Keren, Yonatan; Borisover, Mikhail; Bukhanovsky, Nadezhda

    2015-11-01

    The organic compound-soil interactions may be strongly influenced by changes in soil organic matter (OM) which affects the environmental fate of multiple organic pollutants. The soil OM changes may be caused by land disposal of various OM-containing wastes. One unique type of OM-rich waste is olive mill-related wastewater (OMW) characterized by high levels of OM, the presence of fatty aliphatics and polyphenolic aromatics. The systematic data on effects of the land-applied OMW on organic compound-soil interactions is lacking. Therefore, aqueous sorption of simazine and diuron, two herbicides, was examined in batch experiments onto three soils, including untreated and OMW-affected samples. Typically, the organic compound-soil interactions increased following the prior land application of OMW. This increase is associated with the changes in sorption mechanisms and cannot be attributed solely to the increase in soil organic carbon content. A novel observation is that the OMW application changes the soil-sorbent matrix in such a way that the solute uptake may become cooperative or the existing ability of a soil sorbent to cooperatively sorb organic molecules from water may become characterized by a larger affinity. The remarkable finding of this study was that in some cases a cooperative uptake of organic molecules by soils makes itself evident in distinct sigmoidal sorption isotherms rarely observed in soil sorption of non-ionized organic compounds; the cooperative herbicide-soil interactions may be characterized by the Hill model coefficients. However, no single trend was found for the effect of applied OMW on the mechanisms of organic compound-soil interactions.

  11. The significance of ratios of detritus types and micro-organism productivity to competitive interactions between aquatic insect detritivores.

    PubMed

    Yee, Donald A; Kaufman, Michael G; Juliano, Steven A

    2007-11-01

    Investigations of competitive interactions emphasize non-detrital resources, even though detritus is a major component of most food webs. Studies of competing species focus usually on single resource types, although consumers in nature are likely to encounter mixtures of resource types that may affect whether competition results in exclusion or coexistence. The invasive mosquito Aedes albopictus is capable of excluding the native mosquito Ochlerotatus triseriatus in competition for single detritus types in laboratory and field microcosms. In this study, we used nine ratios of two detritus types (animal and leaf) common in natural containers to test whether detritus ratios affect the outcome of competition. Under intraspecific and interspecific competition, A. albopictus attained higher survival and estimated population growth rate than did O. triseriatus. Unlike past studies, both species had positive growth and high adult survival, with little evidence of competitive effects, under one resource ratio (10:1 ratio of leaf : animal detritus) regardless of mosquito densities, suggesting potential coexistence. Path analysis showed that densities of larvae had negative effects on population growth for O. triseriatus but not for A. albopictus, indicating competitive superiority of A. albopictus. Population growth of both species was affected strongly by the direct paths from animal (positive) and leaf (negative) detritus, and the indirect effect of leaf detritus via bacterial production (positive). Field sampling established that detritus entered real tree holes in ratios similar to those in our experiment, suggesting that natural variation in detritus ratios may influence local coexistence of these species. Seasonal variation in ratios of plant and animal detritus indicated that temporal as well as spatial variation in inputs may be important for potential coexistence.

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

    EPA Science Inventory

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

  13. #2) Enantiomer Specific Measurements of Current-use Pesticides in Aquatic Systems

    EPA Science Inventory

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

  14. Enantiomer Specific Measurements of Current-use Pesticides in Aquatic Systems (#2)

    EPA Science Inventory

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

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

    EPA Science Inventory

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

  16. Spectroscopic characterization of the coordination chemistry and hydrolysis of gallium(III) in the presence of aquatic organic matter

    NASA Astrophysics Data System (ADS)

    Hagvall, Kristoffer; Persson, Per; Karlsson, Torbjörn

    2014-12-01

    Interactions between metals and natural organic matter (NOM) are of great environmental importance and one of the key factors influencing hydrolysis, solubility, and speciation of the metals. However, studying geochemically relevant metals like Al, Fe, and Cu is sometimes associated with analytical problems; for example Fe and Cu are both redox active. Gallium (Ga) is a non-redox active metal that usually occurs at very low concentrations in environmental samples and therefore a wide concentration range of metal(III)-NOM species can be explored by adding Ga(III) to such samples. This makes Ga(III) a good probe and analogue for other metal ions, in particular Al. In addition, due to the increased usage of Ga in society, a better understanding of how Ga interacts with NOM is of importance but such studies are scarce. In this work, Ga(III) interactions with two different organic materials (Suwannee River natural organic matter and Suwannee River fulvic acid) were studied using infrared (IR) and extended X-ray absorption fine structure (EXAFS) spectroscopy in a large experimental range (101-84,076 μg Ga g-1 dry weight; pH 3-8). Our IR spectroscopic results showed that Ga(III) is bonded mainly to carboxylic functional groups and suggested that only a fraction of the total number of carboxylic sites in the samples was actively involved in the bonding. Modeling of the EXAFS data revealed that Ga(III) formed mononuclear chelate complexes with NOM that strongly suppressed the hydrolysis and polymerization of Ga(III). At low Ga(III) concentrations (1675-16,649 μg g-1) organic complexes, consisting of 1-3 chelate ring structures, were the dominating species in the entire pH range while at higher concentrations (67,673-84,076 μg g-1, pH 3.0-7.0) we detected mixtures of mononuclear organic Ga(III) complexes, Ga(III) (hydr)oxide, and free Ga(III) (here defined as the hydrated Ga(III) ion and its soluble hydrolysis products). Moreover, the EXAFS results showed significantly

  17. Photodegradation of fresh terrigenous organic matter contributes to the heterotrophy of boreal aquatic ecosystems in Quebec (Canada)

    NASA Astrophysics Data System (ADS)

    Plouhinec, J.; Lucotte, M. M.; Ouellet, A.; Gelinas, Y.

    2012-12-01

    The processes that fuel heterotrophy and thus contribute to CO2 production in lakes and reservoirs of the boreal region in Quebec are still not fully understood. To shed light on some of the factors controlling heterotrophy, we evaluated the importance of photodechemical mineralization of dissolved organic mater relative to other sources of CO2 production in six natural or human-perturbed lakes through logging on their watersheds and two reservoirs of the Quebec boreal forest over a period of 1.5 year. Rates of CO2 production in the water column were measured through incubation/irradiation experiments, using a series of filtrations to isolate the effects of photochemical mineralization, bacterial respiration, and planktonic respiration. Total CO2 fluxes measured in this study compared well to total diffusive fluxes measured through the traditional thin boundary layer method, thus validating our incubation approach. We calculated the daily integrated production of CO2 through photochemical mineralization (DIPMCO2) of dissolved organic matter over the entire water column using the calculation of the spectrum yield (Φλ). DIPMCO2 appeared as a robust indicator strongly correlated to the absorption coefficient of chromophoric dissolved organic matter (CDOM) at 360 nm (R2=0.81, p<0.01). DIPMCO2 accounts for 15% ± 14% of the total diffusive flux of CO2 to the atmosphere, independently of water body type or perturbation level. Our data also suggests that photochemical mineralization and photosynthesis processes are strongly correlated (R2=0.79, p<0.01), which is due to the fact that the strong photosynthetically active radiation (PAR) attenuation derives from a terrestrial organic matter (TOM) input into the water column. Also, the total diffusive fluxes of CO2 towards the atmosphere (fCO2) are correlated to the DIPMCO2 values (R2=0.49, p<0.01). We have evaluated theoretical CO2 fluxes emitted from the photic zone (f°CO2 ) by photochemical mineralization, bacterial

  18. Toxicity of individual pharmaceuticals and their mixtures to Aliivibrio fischeri: Experimental results for single compounds and considerations of their mechanisms of action and potential acute effects on aquatic organisms.

    PubMed

    Di Nica, Valeria; Villa, Sara; Finizio, Antonio

    2017-03-01

    In the first part of a broader study on the effects of individual and multicomponent mixtures of pharmaceutical active compounds, the authors used the Microtox(®) test system to analyze in detail the effects of 10 widely used human and veterinary pharmaceutical active compounds toward the bioluminescent bacterium Aliivibrio fischeri. The experimental results indicated moderate toxicity for the majority of the tested compounds. Comparison between experimental 50% inhibitory concentrations and those predicted from the quantitative structure-activity relationship models indicated that most of the tested pharmaceutical active compounds behave as polar narcotic compounds toward A. fischeri (only the antibiotic chlortetracycline seemed to have a specific mechanism of action). A comparison between the experimental results and a collection of acute toxicity data on other nontarget organisms indicated that in general A. fischeri has a comparable sensitivity to other aquatic species. However, according to the Globally Harmonized System of Classification and Labelling of Chemicals, the majority of the investigated chemicals can be classified as harmful or nontoxic for aquatic ecosystems. Finally, based on comparisons among the 95th percentile of measured environmental concentrations found in European Union water bodies and acute toxicity data on various aquatic organisms, no risk to aquatic life exists when the tested pharmaceutical active compounds are assessed as individual chemicals. Environ Toxicol Chem 2017;36:807-814. © 2016 SETAC.

  19. New Insights on the Influence of Organic Co-Contaminants on the Aquatic Toxicology of Carbon Nanomaterials.

    PubMed

    Sanchís, Josep; Olmos, Mar; Vincent, Phil; Farré, Marinella; Barceló, Damià

    2016-01-19

    At present, there is a lack of understanding of the combined ecotoxicity of carbon-based nanomaterials and co-contaminants. In this paper, we report on the toxicity of three carbon nanomaterials (fullerene-soot, multiwall carbon nanotubes, and graphene). Two standardized toxicity bioassays, the immobilization of the invertebrate Daphnia magna and the bioluminescence inhibition of the marine bacteria Vibrio fischeri, have been used. Synergistic and antagonistic effects of binary mixtures composed of fullerene soot and organic co-contaminants as malathion, glyphosate, diuron, triclosan, and nonylphenol were assessed. The isobologram method was used to evaluate the concentrations producing an effect, in comparison to those effects expected by a simple additive approach. In this study, antagonism was the predominant effect. However, synergism was also observed as in the case of D. magna exposed to mixtures of malathion and fullerene soot. D. magna was shown to be the most sensitive assay when carbon nanomaterials were present. Toxicity to D. magna was as follows: fullerene soot > multiwall carbon nanotubes > graphene. These results were proportional to the size of aggregates, smaller aggregates being the most toxic. The vector function of nanomaterials aggregates and the unexpected release inside living organisms was proven for malathion. These results highlight new insights on the risks associated with the release of carbon nanomaterials into the environment.

  20. Development of solid-phase microextraction to study dissolved organic matter--polycyclic aromatic hydrocarbon interactions in aquatic environment.

    PubMed

    de Perre, Chloé; Le Ménach, Karyn; Ibalot, Fabienne; Parlanti, Edith; Budzinski, Hélène

    2014-01-07

    Solid-phase microextraction coupled with gas chromatography and mass spectrometry (SPME-GC-MS) was developed for the study of interactions between polycyclic aromatic hydrocarbons (PAHs) and dissolved organic matter (DOM). After the determination of the best conditions of extraction, the tool was applied to spiked water to calculate the dissolved organic carbon water distribution coefficient (K(DOC)) in presence of different mixtures of PAHs and Aldrich humic acid. The use of deuterated naphthalene as internal standard for freely dissolved PAH quantification was shown to provide more accuracy than regular external calibration. For the first time, K(DOC) values of 18 PAHs were calculated using data from SPME-GC-MS and fluorescence quenching; they were in agreement with the results of previous studies. Competition between PAHs, deuterated PAHs and DOM was demonstrated, pointing out the non-linearity of PAH-DOM interactions and the stronger interactions of light molecular weight PAHs (higher K(DOC) values) in absence of high molecular weight PAHs.

  1. Aquatic Plants and Animals as Ecosystem Engineers

    NASA Astrophysics Data System (ADS)

    Wotton, R. S.

    2005-05-01

    Studies on aquatic plants and animals focus on population dynamics, the structure of communities and the part played by organisms in food webs and other ecosystem processes. As Lawton and Jones point out in "Linking Species and Ecosystems", less attention is given to the role of organisms as ecosystem engineers, modifying the environment in which they live. Yet plants can have a profound effect on their surroundings, altering flow patterns and trapping large amounts of organic and inorganic material. Animals also affect aquatic ecosystems in many ways, both in building structures such as tubes and shelters, and in their feeding. For example, detritus feeders often produce large numbers of faecal pellets (and pseudofaeces in bivalves) and these are very different in size to the materials ingested. Pellets are deposited in masses over the bed of streams, lakes and the sea and therefore effect a translocation of nutrients. The action of plants and animals in altering their environment is likely to be a significant process in all water bodies, from both small to large scale.

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

    NASA Astrophysics Data System (ADS)

    Pant, H. K.

    2007-12-01

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

  3. GULF OF MEXICO AQUATIC MORTALITY NETWORK (GMNET)

    EPA Science Inventory

    Five U.S. states share the northern coast of the Gulf, and each has a program to monitor mortalities of aquatic organisms (fish, shellfish, birds). However, each state has different standards, procedures, and documentation of mortality events. The Gulf of Mexico Aquatic Mortality...

  4. Evaluation of the risk of mixtures of paddy insecticides and their transformation products to aquatic organisms in the Sakura River, Japan.

    PubMed

    Iwafune, Takashi; Yokoyama, Atsushi; Nagai, Takashi; Horio, Takeshi

    2011-08-01

    To assess the risk of mixtures of six paddy insecticides and their transformation products (TPs) to aquatic organisms in the Sakura River, Japan, their concentrations in the river water were monitored during the rice cultivation season in 2008 and 2009, and acute toxicity tests for Cheumatopsyche brevilineata (caddisflies) and Daphnia magna (daphnids), surrogate test species for caddisflies and cladocerans, respectively, were conducted. The mixture of fipronil, applied in the rice nursery box, and its desulfinyl, sulfide, and sulfone TPs were detected in the river for several months after transplanting, and they were more toxic to C. brevilineata than the other tested compounds. The toxicities of the parent compound and its TPs, such as fipronil and its TPs, may be related to their hydrophobicities. Risk quotients for mixtures (RQ(mix)) of only parent compounds did not exceed 1, but, in mid-June 2009, the RQ(mix) of parent compounds and TPs for caddisflies exceeded 1. Diazinon, fenitrothion, and fenthion sprayed on the rice crop and their TPs posed a sporadic risk for cladocerans, depending on the application timing, whereas fipronil TPs contributed to the RQ(mix) for caddisflies for several months after transplanting. The risk of mixtures of insecticides and their TPs differed seasonally between caddisflies and cladocerans, depending on insecticide application timing and the persistence and toxicity of TPs.

  5. Instrument design and protocol for the study of light controlled processes in aquatic organisms, and its application to examine the effect of infrared light on zebrafish.

    PubMed

    Dekens, Marcus P S; Foulkes, Nicholas S; Tessmar-Raible, Kristin

    2017-01-01

    The acquisition of reliable data strongly depends on experimental design. When studying the effects of light on processes such as behaviour and physiology it is crucial to maintain all environmental conditions constant apart from the one under study. Furthermore, the precise values of the environmental factors applied during the experiment should be known. Although seemingly obvious, these conditions are often not met when the effects of light are being studied. Here, we document and discuss the wavelengths and light intensities of natural and artificial light sources. We present standardised experimental protocols together with building plans of a custom made instrument designed to accurately control light and temperature for experiments using fresh water or marine species. Infrared light is commonly used for recording behaviour and in electrophysiological experiments although the properties of fish photoreceptors potentially allow detection into the far red. As an example of our experimental procedure we have applied our protocol and instrument to specifically test the impact of infrared light (840 nm) on the zebrafish circadian clock, which controls many aspects of behaviour, physiology and metabolism. We demonstrate that infrared light does not influence the zebrafish circadian clock. Our results help to provide a solid framework for the future study of light dependent processes in aquatic organisms.

  6. Instrument design and protocol for the study of light controlled processes in aquatic organisms, and its application to examine the effect of infrared light on zebrafish

    PubMed Central

    Dekens, Marcus P. S.; Foulkes, Nicholas S.; Tessmar-Raible, Kristin

    2017-01-01

    The acquisition of reliable data strongly depends on experimental design. When studying the effects of light on processes such as behaviour and physiology it is crucial to maintain all environmental conditions constant apart from the one under study. Furthermore, the precise values of the environmental factors applied during the experiment should be known. Although seemingly obvious, these conditions are often not met when the effects of light are being studied. Here, we document and discuss the wavelengths and light intensities of natural and artificial light sources. We present standardised experimental protocols together with building plans of a custom made instrument designed to accurately control light and temperature for experiments using fresh water or marine species. Infrared light is commonly used for recording behaviour and in electrophysiological experiments although the properties of fish photoreceptors potentially allow detection into the far red. As an example of our experimental procedure we have applied our protocol and instrument to specifically test the impact of infrared light (840 nm) on the zebrafish circadian clock, which controls many aspects of behaviour, physiology and metabolism. We demonstrate that infrared light does not influence the zebrafish circadian clock. Our results help to provide a solid framework for the future study of light dependent processes in aquatic organisms. PMID:28212399

  7. Is there a risk for the aquatic environment due to the existence of emerging organic contaminants in treated domestic wastewater? Greece as a case-study.

    PubMed

    Thomaidi, Vasiliki S; Stasinakis, Athanasios S; Borova, Viola L; Thomaidis, Nikolaos S

    2015-01-01

    The ecological threat associated with emerging pollutants detected in wastewater was estimated in country level. Treated wastewater was analyzed for pharmaceuticals and illicit drugs; whereas the concentrations of all emerging contaminants determined in Greek Sewage Treatment Plants were recorded through literature review. Toxicity data was collected after literature review or using ECOSAR and risk quotients (RQs) were calculated for treated wastewater and 25 Greek rivers, for 3 different aquatic organisms (fish, daphnia magna, algae). According to the results, monitoring data was available for 207 micropollutants belonging to 8 different classes. RQ>1 was calculated for 30 compounds in secondary treated wastewater. Triclosan presented RQ>1 (in algae) for all studied rivers; decamethylcyclopentasilane (in daphnia magna), caffeine (in algae) and nonylphenol (in fish) presented RQ>1 in rivers with dilution factors (DF) equal or lower to 1910, 913 and 824, respectively. The class of emerging contaminants that present the greatest threat due to single or mixture toxicity was endocrine disrupters. The mixture of microcontaminants seems to pose significant ecological risk, even in rivers with DF equal to 2388. Future national monitoring programs should include specific microcontaminants that seem to possess environment risk to surface water.

  8. Movement, transport, and scour of particulate organic matter and aquatic invertebrates downstream from a peaking hydropower project. Final report

    SciTech Connect

    Matter, W.; Hudson, P.; Nestler, J.; Saul, G.

    1983-05-01

    The Savannah River below Lake Hartwell, Georgia-South Carolina, receives hypolimnetic water discharged from the reservoir for peak power generation. Invertebrates and particulate organic material (POM) in the water column were collected during a 24-hr release cycle at sites 1.0, 4.5, and 12.5 km downstream from the dam. Water released during generation reached a maximum discharge of 688 cum/sec. River discharge was less than 10 cum/sec during nongeneration periods. Highest POM concentrations were associated with the initial downstream surge of water at the start of power generation; values were 200 to 400 times greater than those during nongeneration periods. Of the drifting invertebrates, 80 to 93 percent originated in the reservoir; the rest, primarily Oligochaeta, Diptera, and Ephemeroptera, were from the tailwater.

  9. Pb-binding to various dissolved organic matter in urban aquatic systems: Key role of the most hydrophilic fraction

    NASA Astrophysics Data System (ADS)

    Pernet-Coudrier, Benoît; Companys, Encarnació; Galceran, Josep; Morey, Margalida; Mouchel, Jean-Marie; Puy, Jaume; Ruiz, Núria; Varrault, Gilles

    2011-07-01

    Dissolved organic matter (DOM) from the treated effluent of a wastewater treatment plant and from the river Seine under high human pressure has been separated into three fractions: hydrophobic (containing humic and fulvic substances), transphilic and hydrophilic using a two column array of XAD-8 and XAD-4 resins. The acid base properties and the binding characteristics with respect to Pb ions (using the new electroanalytical technique AGNES, Absence of Gradients and Nernstian Equilibrium Stripping) have been studied and fitted to NICA (Non-Ideal Competitive Isotherm). We evaluated the binding potential of each DOM fraction in order to better predict the speciation of Pb and, later, its bioavailability in the river. The total binding capacity of the different fractions to Pb, as well as the total titratable charge, reaches its maximum value at the most hydrophilic fraction from the treated effluent. Specific properties of the distribution of the complexing sites within each DOM fraction have been exposed by plotting the conditional affinity spectrum (CAS). The addition of these distributions, weighted according to the respective abundance of each organic fraction, allows for a full description of the Pb binding properties of the whole DOM of a sampling site. Despite its weak aromaticity, the hydrophilic fraction from the wastewater treatment plant effluent exhibits a high lead binding affinity, so that at typical environmental pH and free Pb levels (0.1 μg L -1), Pb is mainly bound to the most hydrophilic fraction of the treated effluent (49% of bound Pb at pH 7). This feature may greatly enhance the transport of Pb and highlights that Pb speciation should also consider other fractions apart from humic and/or fulvic acids when studying surface waters under high human pressure.

  10. Carbon and silver nanoparticles in the fight against the filariasis vector Culex quinquefasciatus: genotoxicity and impact on behavioral traits of non-target aquatic organisms.

    PubMed

    Murugan, Kadarkarai; Nataraj, Devaraj; Madhiyazhagan, Pari; Sujitha, Vasu; Chandramohan, Balamurugan; Panneerselvam, Chellasamy; Dinesh, Devakumar; Chandirasekar, Ramachandran; Kovendan, Kalimuthu; Suresh, Udaiyan; Subramaniam, Jayapal; Paulpandi, Manickam; Vadivalagan, Chithravel; Rajaganesh, Rajapandian; Wei, Hui; Syuhei, Ban; Aziz, Al Thabiani; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Nicoletti, Marcello; Canale, Angelo; Benelli, Giovanni

    2016-03-01

    Mosquito-borne diseases represent a deadly threat for millions of people worldwide. The Culex genus, with special reference to Culex quinquefasciatus, comprises the most common vectors of filariasis across urban and semi-urban areas of Asia. In recent years, important efforts have been conducted to propose green-synthesized nanoparticles as a valuable alternative to synthetic insecticides. However, the mosquitocidal potential of carbon nanoparticles has been scarcely investigated. In this study, the larvicidal and pupicidal activity of carbon nanoparticle (CNP) and silver nanoparticle (AgNP) was tested against Cx. quinquefasciatus. UV-Vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, and Raman analysis confirmed the rapid and cheap synthesis of carbon and silver nanoparticles. In laboratory assays, LC50 (lethal concentration that kills 50 % of the exposed organisms) values ranged from 8.752 ppm (first-instar larvae) to 18.676 ppm (pupae) for silver nanoparticles and from 6.373 ppm (first-instar larvae) to 14.849 ppm (pupae) for carbon nanoparticles. The predation efficiency of the water bug Lethocerus indicus after a single treatment with low doses of silver and carbon nanoparticles was not reduced. Moderate evidence of genotoxic effects induced by exposure to carbon nanoparticles was found on non-target goldfish, Carassius auratus. Lastly, the plant extract used for silver nanosynthesis was tested for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity. Overall, our results pointed out that AgNP and CNP can be a candidate for effective tools to reduce larval and pupal populations of filariasis vectors, with reduced genotoxicity and impact on behavioral traits of other aquatic organisms sharing the same ecological

  11. Influences of solution chemistry and polymeric natural organic matter on the removal of aquatic pharmaceutical residuals by nanofiltration.

    PubMed

    Zazouli, Mohammad Ali; Susanto, Heru; Nasseri, Simin; Ulbricht, Mathias

    2009-07-01

    This study demonstrates the removal efficiency and the permeate flux behavior during cross-flow nanofiltration (NF) of aqueous solutions of five pharmaceutically active compounds (PhACs). Cephalexin, tetracycline, acetaminophen, indomethacin and amoxicillin were used as models of PhACs, and alginate was selected as model of natural organic matter (NOM). Two commercial composite NF membranes (SR2 and SR3) with different characteristics were used. The highest rejection was observed for tetracycline, i.e., 75-95% for membrane SR 2 and 95-100% for membrane SR 3, while the rejection was least for acetaminophen (32-36% for SR2 and 52-59% for SR3). As the pH of acetaminophen solution was increased (from 6 to 9) the rejection would increase. Changes of ionic content (from 10 to 20mM) lead to increase (from 89 to 93% for SR 3) or decrease (from 100 to 91% for SR2) of cephalexin rejection depending on the membrane used. The permeate flux would decrease with decreasing the pH solution and increasing ionic strength. The addition of alginate in the feed stream decreased the permeate flux, with lower reduction for SR3, and increased the PhAC rejection except for acetaminophen and amoxicillin. Both size and Donnan exclusions seemed to occur, and the effect of Donnan exclusion was more pronounced for the NF membrane having larger effective pore size (SR2).

  12. Sorption and competition of two persistent organic pesticides onto marine sediments: Relevance to their distribution in aquatic system.

    PubMed

    Soubaneh, Youssouf Djibril; Gagné, Jean-Pierre; Lebeuf, Michel; Nikiforov, Vladimir; Gouteux, Bruno; Osman, Awaleh Mohamed

    2015-07-01

    Sorption is a key process in the distribution of substances between environmental compartments in marine ecosystems. Two persistent organic pesticides, also known as toxaphene congeners, namely B8-1413 (P26) and B9-1679 (P50), are of special interest because they are not detected in sediments while relatively concentrated in marine mammals. Sorption-desorption, entrapment and competition behaviors of these pesticides onto marine sediments were studied to explain their environmental distribution. Data obtained under marine experimental conditions were fitted to sorption models to evaluate sorption coefficients and to assess the degree of B8-1413/B9-1679 entrapment of the two toxaphene congeners in sediments. Carbon normalized sorption coefficients (Koc) of both congeners were similar under in cold (2°C) marine (30 psu) conditions with high values ranging from 1.53×10(5) to 3.28×10(5) mL g(-1)indicative of a strong affinity to marine sediments However, the sorption-desorption investigations indicate that B8-1413/B9-1679 were on average 2.5 times less entrapped in sediments compared to B7-1450, a toxaphene congener known to accumulate predominantly in sediments. These results suggest that the low entrapment of B8-1413 and B9-1679 favor their availability and transfer to biological matrices.

  13. Facile biosynthesis of silver nanoparticles using Barleria cristata: mosquitocidal potential and biotoxicity on three non-target aquatic organisms.

    PubMed

    Govindarajan, Marimuthu; Benelli, Giovanni

    2016-03-01

    Mosquitoes (Diptera: Culicidae) act as vectors of important pathogens and parasites, such as malaria, dengue, chikungunya, Japanese encephalitis and lymphatic filariasis. The use of synthetic mosquitocides often leads to high operational costs and adverse non-target effects. Recently, plant-borne compounds have been proposed for rapid extracellular biosynthesis of mosquitocidal nanoparticles. However, the impact of these nanomosquitocides against biological control agents of mosquito larval populations has been poorly studied. In this research, we biosynthesized silver nanoparticles (Ag NP) using the Barleria cristata leaf extract as a reducing and stabilizing agent. The biosynthesis of Ag NP was confirmed analyzing the excitation of surface plasmon resonance using ultraviolet-visible (UV-vis) spectrophotometry. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed the clustered and irregular shapes of Ag NP. The presence of silver was confirmed by energy-dispersive X-ray (EDX) spectroscopy. Fourier transform infrared (FTIR) spectroscopy investigated the identity of secondary metabolites, which may also act as Ag NP capping agents. The acute toxicity of B. cristata leaf extract and biosynthesized Ag NP was evaluated against larvae of Anopheles subpictus, Aedes albopictus, and Culex tritaeniorhynchus. Compared to the leaf aqueous extract, biosynthesized Ag NP showed higher toxicity against An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus with lethal concentration (LC)50 values of 12.46, 13.49, and 15.01 μg/mL, respectively. Notably, biosynthesized Ag NP were found safer to non-target organisms Diplonychus indicus, Anisops bouvieri, and Gambusia affinis, with respective LC50 values ranging from 633.26 to 866.92 μg/mL. Overall, our results highlight that B. cristata-fabricated Ag NP are a promising and eco-friendly tool against young instar populations of mosquito vectors of medical and veterinary importance.

  14. Comparison of seasonal changes in fluorescent dissolved organic matter among aquatic lake and stream sites in the Green Lakes Valley

    NASA Astrophysics Data System (ADS)

    Miller, Matthew P.; McKnight, Diane M.

    2010-03-01

    The spectral characteristics of whole water dissolved organic matter (DOM) and fulvic acid were studied in samples collected from an alpine lake, a subalpine lake, and a subalpine stream during snowmelt and the summer growing season. Excitation-emission matrices of whole water DOM and fulvic acid were analyzed by parallel factor analysis (PARAFAC). Allochthonous inputs of terrestrially derived fulvic acid DOM were dominant during snowmelt at the alpine lake, and during both snowmelt and summer at the subalpine sites. At the alpine lake, autochthonous inputs of DOM dominated during the summer phytoplankton bloom, and the spectral characteristics of the whole water DOM diverged from those of the fulvic acid. For example, the quinone-like fluorophores in whole water DOM at the alpine lake were more oxidized and microbially derived than the fulvic acid fraction during the summer. At the subalpine sites, the seasonal changes in the source and redox state of the quinone-like fluorophores of the whole water DOM tracked those of the fulvic acid pool. However, at both lake sites there was a greater contribution of amino acid-like fluorophores in the whole water DOM than the fulvic acid fraction. This trend was not observed at the subalpine stream site. Principal components analysis (PCA) of the PARAFAC components suggests that during snowmelt, the chemical quality of the DOM at the alpine lake was similar to that of the subalpine stream; whereas the alpine site was more similar to the subalpine lake during the summer. Spectral characterization and PCA of the PARAFAC components suggest that nonhumic quinone-like and amino acid-like fluorophores were produced in the alpine lake during the summer phytoplankton bloom. Our results show that different types of water bodies produce different seasonal patterns in whole water DOM and fulvic acid quantity and quality.

  15. Soluble organic carbon and pH of organic amendments affect metal mobility and chemical speciation in mine soils.

    PubMed

    Pérez-Esteban, Javier; Escolástico, Consuelo; Masaguer, Alberto; Vargas, Carmen; Moliner, Ana

    2014-05-01

    We evaluated the effects of pH and soluble organic carbon affected by organic amendments on metal mobility to find out the optimal conditions for their application in the stabilization of metals in mine soils. Soil samples (pH 5.5-6.2) were mixed with 0, 30 and 60 th a(-1) of sheep-horse manure (pH 9.4) and pine bark compost (pH 5.7). A single-step extraction procedure was performed using 0.005 M CaCl2 adjusted to pH 4.0-7.0 and metal speciation in soil solution was simulated using NICA-Donnan model. Sheep-horse manure reduced exchangeable metal concentrations (up to 71% Cu, 75% Zn) due to its high pH and degree of maturity, whereas pine bark increased them (32% Cu, 33% Zn). However, at increasing dose and hence pH, sheep-horse manure increased soluble Cu because of higher soluble organic carbon, whereas soluble Cu and organic carbon increased at increasing dose and correspondingly decreasing pH in pine bark and non-amended treatments. Near the native pH of these soils (at pH 5.8-6.3), with small doses of amendments, there was minimum soluble Cu and organic carbon. Pine bark also increased Zn solubility, whereas sheep-horse manure reduced it as soluble Zn always decreased with increasing pH. Sheep-horse manure also reduced the proportion of free metals in soil solution (from 41% to 4% Cu, from 97% to 94% Zn), which are considered to be more bioavailable than organic species. Sheep-horse manure amendment could be efficiently used for the stabilization of metals with low risk of leaching to groundwater at low doses and at relatively low pH, such as the native pH of mine soils.

  16. Studies on the toxic elements and organic degradation products in aquatic bodies and sediments around Kennedy Space Center (KSC) South Mosquito lagoon

    NASA Technical Reports Server (NTRS)

    Ghuman, G. S.; Menon, M. P.; Emeh, C. O.

    1978-01-01

    A compilation was put together of research work performed on the aquatic systems around Kennedy Space Center (KSC). The report includes a brief description of the study area, field data and analytical results of all the samples collected during the five visits to KSC up to December 17, 1977. The aquatic area selected for the study is the Southern part of Mosquito Lagoon which extends from the Haulover Canal to the dead end boundary of this lagoon southwards.

  17. Identification of detoxification pathways in plants that are regulated in response to treatment with organic compounds isolated from oil sands process-affected water.

    PubMed

    Widdup, Ellen E; Chatfield-Reed, Kate; Henry, Darren; Chua, Gordon; Samuel, Marcus A; Muench, Douglas G

    2015-11-01

    Bitumen mining in the Athabasca oil sands region of northern Alberta results in the accumulation of large volumes of oil sands process-affected water (OSPW). The acid-extractable organic (AEO) fraction of OSPW contains a variety of compounds, including naphthenic acids, aromatics, and sulfur- and nitrogen-containing compounds that are toxic to aquatic and terrestrial organisms. We have studied the effect of AEO treatment on the transcriptome of root and shoot tissues in seedlings of the model plant, Arabidopsis thaliana. Several genes encoding enzymes involved in the xenobiotic detoxification pathway were upregulated, including cytochrome P450s (CYPs), UDP-dependent glycosyltransferases (UGTs), glutathione-S-transferases (GSTs), and membrane transporters. In addition, gene products involved in oxidative stress, β-oxidation, and glucosinolate degradation were also upregulated, indicating other potential mechanisms of the adaptive response to AEO exposure. These results provide insight into the pathways that plants use to detoxify the organic acid component of OSPW. Moreover, this study advances our understanding of genes that could be exploited to potentially develop phytoremediation and biosensing strategies for AEO contaminants resulting from oil sands mining.

  18. [The forensic medical evaluation of traumatic and spontaneous ruptures of the organs affected by the tumours].

    PubMed

    Pigolkin, Yu I; Dolzhansky, O V; Pal'tseva, E M; Shilova, M A; Fedorov, D N; Boeva, S E

    2017-01-01

    The present article was designed to report the results of the analysis of the cases of traumatic and spontaneous ruptures of the organs affected by the tumours based on the original observations and the literature data. It is shown that the probability of the tumour rupture depends on its histological type, localization, the size, and the distance from the capsule of the affected organ, the degree of involvement of the major blood vessels, the severity of the necrotic changes, the presence of cysts in the neoplasm, and the regimens of radio- and chemotherapy. Moreover, the rupture can be facilitated by anticoagulation therapy, intake or oral contraceptives, pregnancy, concomitant diseases, alcoholic intoxication, splenomegaly, and hypocoagulation resulting from dissemination of the neoplastic process or the metastatic lesions of the liver. Even a minimal injury to the skin can provoke the tumour rupture associated with the fatal hemorrhage. A delayed rupture within a few hours or days is possible.

  19. Using solid (13)C NMR coupled with solution (31)P NMR spectroscopy to investigate molecular species and lability of organic carbon and phosphorus from aquatic plants in Tai Lake, China.

    PubMed

    Liu, Shasha; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Wang, Hao; He, Zhongqi; Guo, Wenjing; Song, Fanhao; Giesy, John P

    2017-01-01

    Forms and labilities of plant-derived organic matters (OMs) including carbon (C) and phosphorus (P) were fundamental for understanding their release, degradation and environmental behaviour in lake ecosystems. Thus, solid (13)C and solution (31)P nuclear magnetic resonance (NMR) spectroscopy were used to characterize biomass of six aquatic plants in Tai Lake, China. The results showed that carbohydrates (61.2% of the total C) were predominant C functional group in the solid (13)C NMR spectra of plant biomass, which may indicate high lability and bioavailability of aquatic plants-derived organic matter in lakes. There was 72.6-103.7% of the total P in aquatic plant biomass extracted by NaOH-EDTA extracts. Solution (31)P NMR analysis of these NaOH-EDTA extracts further identified several molecular species of P including orthophosphate (50.1%), orthophosphate monoesters (46.8%), DNA (1.6%) and pyrophosphate (1.4%). Orthophosphate monoesters included β-glycerophosphate (17.7%), hydrolysis products of RNA (11.7%), α-glycerophosphate (9.2%) and other unknown monoesters (2.1%). Additionally, phytate, the major form of organic P in many lake sediments, was detected in floating plant water poppy. These inorganic P (e.g. orthophosphate and pyrophosphate) and organic P (e.g. diester and its degradation products) identified in plant biomass were all labile and bioavailable P, which would play an important role in recycling of P in lakes. These results increased knowledge of chemical composition and bioavailability of OMs derived from aquatic plants in lakes.

  20. Zebrafish as a model for zoonotic aquatic pathogens

    PubMed Central

    Rowe, Hannah M.; Withey, Jeffrey H.; Neely, Melody N.

    2014-01-01

    Aquatic habitats harbor a multitude of bacterial species. Many of these bacteria can act as pathogens to aquatic species and/or non-aquatic organisms, including humans, that come into contact with contaminated water sources or colonized aquatic organisms. In many instances, the bacteria are not pathogenic to the aquatic species they colonize and are only considered pathogens when they come into contact with humans. There is a general lack of knowledge about how the environmental lifestyle of these pathogens allows them to persist, replicate and produce the necessary pathogenic mechanisms to successfully transmit to the human host and cause disease. Recently, the zebrafish infectious disease model has emerged as an ideal system for examining aquatic pathogens, both in the aquatic environment and during infection of the human host. This review will focus on how the zebrafish has been used successfully to analyze the pathogenesis of aquatic bacterial pathogens. PMID:24607289

  1. Soil organic matter transformation in cryoturbated horizons of permafrost affected soils

    NASA Astrophysics Data System (ADS)

    Capek, Petr; Diakova, Katerina; Dickopp, Jan-Erik; Barta, Jiri; Santruckova, Hana; Wild, Birgit; Schnecker, Joerg; Guggenberg, Georg; Gentsch, Norman; Hugelius, Gustaf; Kuhry, Peter; Lashchinsky, Nikolaj; Gittel, Antje; Schleper, Christa; Mikutta, Robert; Palmtag, Juri; Shibistova, Olga; Urich, Tim; Zimov, Sergey; Richter, Andreas

    2014-05-01

    Cryoturbated soil horizons are special feature of permafrost affected soils. These soils are known to store great amount of organic carbon and cryoturbation undoubtedly contribute to it to large extent. Despite this fact there is almost no information about soil organic matter (SOM) transformation in cryoturbated horizons. Therefore we carried out long term incubation experiment in which we inspect SOM transformation in cryoturbated as well as in organic and mineral soil horizons under different temperature and redox regimes as potential drivers. We found out that lower SOM transformation in cryoturbated horizons compared to organic horizons was mainly limited by the amount of microbial biomass, which is extremely low in absolute numbers or expressed to SOM concentration. The biochemical transformation ensured by extracellular enzymes is relatively high leading to high concentrations of dissolved organic carbon in cryoturbated horizons. Nevertheless the final step of SOM transformation leading to C mineralization to CO2 or CH4 seems to be restricted by low microbial biomass. Critical step of biochemical transformation of complex SOM is dominated by phenoloxidases, which break down complex organic compounds to simple ones. Their oxygen consumption greatly overwhelms oxygen consumption of the whole microbial community. However the phenoloxidase activity shows strong temperature response with optimum at 13.7° C. Therefore we suggest that apparent SOM stability in cryoturbated horizons, which is expressed in old C14 dated age, is caused by low amount of microbial biomass and restricted diffusion of oxygen to extracellular enzymes in field.

  2. Thinking Big or Small: Does Mental Abstraction Affect Social Network Organization?

    PubMed Central

    Bacev-Giles, Chantal; Peetz, Johanna

    2016-01-01

    Four studies examined how mental abstraction affects how people perceive their relationships with other people, specifically, how these relationships may be categorized in social groups. We expected that individuals induced to think abstractly would report fewer more global social groups, compared to those induced to think concretely, who would report more specific groups. However, induced abstract mindset did not affect how people structured their social groups (Study 2–4), despite evidence that the mindset manipulation changed the level of abstraction in their thoughts (Study 3) and evidence that it changed how people structured groups for a control condition (household objects, Study 4). Together, these studies suggest that while the way people organize their relationships into groups is malleable; cognitive abstraction does not seem to affect how people categorize their relationships into social groups. PMID:26808086

  3. Acute toxicity of smoke screen materials to aquatic organisms, white phosphorus-felt, red phosphorus-butyl rubber and SGF No. 2 fog oil. Final report

    SciTech Connect

    Poston, T.M.; McFadden, K.M.; Bean, R.M.; Clark, M.L.; Thomas, B.L.; Killand, B.W.; Prohammer, L.A.; Kalkwarf, D.R.

    1986-04-01

    The acute toxicity of three obscurants was determined for nine freshwater organisms. The materials tested were white phosphorus-felt smoke, red phosphorus-butyl rubber (RP-BR) smoke, and smoke generator fuel (SGF) No. 2 fog oil (bulk and vaporized). The chemistry of WP-F and RP-BR smoke in water and the resulting effects on aquatic organisms are similar. Combustion of these two obscurants and their deposition in water leads to the formation of many complex oxy-phosphoric acids. Rates of hydrolysis of these complex products to ortho-phosphate were inconsistent and unpredictable over time. These products acidify water and produce toxic effects after exhausting the buffering capacity of the water. Acute 96 hr tests using Daphnia magna with neutralized and nonneutralized exposure solutions indicated that the presence of unidentified toxic component(s) acted independently of pH. At pH levels of 6.0 to 7.0, phosphorus combustion products precipitated out of solution leading to a bimodal toxic response in extended 96-hr tests with Daphnia magna. Most components of fog oil had low solubility in water. Saturation was apparent at approximately 0.1 to 0.3 mg/L total oil. Vaporization had no demonstrable effect on the chemistry or toxicity of the fog oil. Neither the bulk fog oil nor the vaporized fog oil was acutely toxic to freshwater animals at concentrations less than 10 mg/L total oil. In oil-water mixes in excess of 1.0 mg/L total oil, fog oil quickly separated and floated to the surface. The primary hazard associated with vaporized and bulk fog oil was the physical effect of oil fouling the organisms. Photolysis increased the concentration of water-soluble components of the fog oil. Acute toxicity was demonstrated in oil-water mixes (approx.10 mg/L total oil) of photolyzed bulk and vaporized fog oil. No difference in toxicity was observed between photolyzed and non-photolyzed dilutions of OWM at comparable levels of total oil.

  4. SYNOPSIS OF HISTOTECHNIQUES FOR AQUATIC ANIMALS

    EPA Science Inventory

    This synopsis provides an overview of the necropsy, fixation, trimming, and processing of tissues from aquatic organisms for examination using light microscopy. The handling of animals, their tissues, uses of knives, and processing chemicals will be covered. Understanding the his...

  5. Soil organic carbon pools and stocks in permafrost-affected soils on the tibetan plateau.

    PubMed

    Dörfer, Corina; Kühn, Peter; Baumann, Frank; He, Jin-Sheng; Scholten, Thomas

    2013-01-01

    The Tibetan Plateau reacts particularly sensitively to possible effects of climate change. Approximately two thirds of the total area is affected by permafrost. To get a better understanding of the role of permafrost on soil organic carbon pools and stocks, investigations were carried out including both discontinuous (site Huashixia, HUA) and continuous permafrost (site Wudaoliang, WUD). Three organic carbon fractions were isolated using density separation combined with ultrasonic dispersion: the light fractions (<1.6 g cm(-3)) of free particulate organic matter (FPOM) and occluded particulate organic matter (OPOM), plus a heavy fraction (>1.6 g cm(-3)) of mineral associated organic matter (MOM). The fractions were analyzed for C, N, and their portion of organic C. FPOM contained an average SOC content of 252 g kg(-1). Higher SOC contents (320 g kg(-1)) were found in OPOM while MOM had the lowest SOC contents (29 g kg(-1)). Due to their lower density the easily decomposable fractions FPOM and OPOM contribute 27% (HUA) and 22% (WUD) to the total SOC stocks. In HUA mean SOC stocks (0-30 cm depth) account for 10.4 kg m(-2), compared to 3.4 kg m(-2) in WUD. 53% of the SOC is stored in the upper 10 cm in WUD, in HUA only 39%. Highest POM values of 36% occurred in profiles with high soil moisture content. SOC stocks, soil moisture and active layer thickness correlated strongly in discontinuous permafrost while no correlation between SOC stocks and active layer thickness and only a weak relation between soil moisture and SOC stocks could be found in continuous permafrost. Consequently, permafrost-affected soils in discontinuous permafrost environments are susceptible to soil moisture changes due to alterations in quantity and seasonal distribution of precipitation, increasing temperature and therefore evaporation.

  6. Field and laboratory studies on the impact of two Bt rice lines expressing a fusion protein Cry1Ab/1Ac on aquatic organisms.

    PubMed

    Wang, Yongmo; Huang, Jiacheng; Hu, Huawei; Li, Jianhong; Liu, Biao; Zhang, Guoan

    2013-06-01

    Genetically modified (GM) rice expressing Bt toxins is at the edge of commercial release in China. However, little information is available concerning the impact of Bt rice on aquatic organisms which are abundant in paddy field. A two-year study was conducted to assess the effects of two GM rice lines expressing a fusion protein Cry1Ab/1Ac (Bt rice) on three groups of zooplankton, rotifers, cladocerans and copepods in field conditions. Multi-factor ANOVA revealed that the population densities of rotifers, cladocerans and copepods in paddy field varied significantly between years and rice developmental stages, but did not differ significantly between Bt and non-Bt rice treatments. In all the field investigations, only one significant difference was found on copepods in the tillering stage of 2009, but the difference was not related to the presence of the Cry toxin. Under open-air conditions, we simulated the farming practice of straw mulch, using Bt rice straw as a food source for the water flea Daphnia hyalina. After one and two months of culture, the density of D. hyalina did not differ between Bt rice treatments and non-Bt rice treatments. A laboratory experiment found that purified Bt toxins Cry1Ab and Cry1Ac had no toxic effect on D. hyalina even in the treatment in which the Bt toxin concentration was as high as 2500ng/ml. Those above results indicate that the two Bt rice lines have no negative effect on the three groups of zooplankton. However, further studies are needed to compare the effects of Bt rice and non-Bt rice on the paddy zooplankton community in the context of integrated pest management which includes the use of pesticides.

  7. Demographic and Clinical Findings in Pediatric Patients Affected by Organic Acidemia

    PubMed Central

    NAJAFI, Reza; HASHEMIPOUR, Mahin; MOSTOFIZADEH, Neda; GHAZAVI, Mohammadreza; NASIRI, Jafar; SHAHSANAI, Armindokht; FAMORI, Fatemeh; NAJAFI, Fatemeh; MOAFI, Mohammad

    2016-01-01

    Objective Metabolic disorders, which involve many different organs, can be ascribed to enzyme deficiency or dysfunction and manifest with a wide range of clinical symptoms. This study evaluated some of the demographic and clinical findings in pediatric patients affected by organic acidemia. Materials & Methods This cross-sectional study was part of a larger study conducted in patients with metabolic disorders during a period of 7 years from 2007 to 2014 in Isfahan Province, Iran. Our study covered a wide range of cases from newborn infants (one-week old) to adolescents (children up to the age of 17 years). This study evaluated patients’ demographic information, history of disease, developmental and educational status, clinical and general conditions. Phone and in-person interviews were used to gather information. Results Out of 5100 patients screened in this study, 392 patients were affected by one of the different metabolic disorders and 167 individuals were diagnosed as organic acidemia. Propionic acidemia/methyl malonic acidemia (PA/MMA) was the most prevalent form of this metabolic disorder. The frequency of consanguinity was 84.7% in the group of patients. The mortality rate was 18.8% in patients with organic academia. Conclusion Each of the metabolic diseases, as a separate entity, is rare; nevertheless, in aggregate they have a somewhat high overall prevalence. These diseases result in mental and developmental disorders in the absence of quick diagnosis and initiation of treatment. Furthermore, more mutations should be identified in societies affected by consanguinity. Further research should also be conducted to determine worthwhile and more-efficient screening methods as well as long term neurological prognosis. PMID:27247587

  8. A novel technique for the precise measurement of CO2 production rate in small aquatic organisms as validated on aeshnid dragonfly nymphs.

    PubMed

    Harter, Till S; Brauner, Colin J; Matthews, Philip G D

    2017-03-15

    The present study describes and validates a novel yet simple system for simultaneous in vivo measurements of rates of aquatic CO2 production (ṀCO2 ) and oxygen consumption (ṀO2 ), thus allowing the calculation of respiratory exchange ratios (RER). Diffusion of CO2 from the aquatic phase into a gas phase, across a hollow fibre membrane, enabled aquatic ṀCO2  measurements with a high-precision infrared gas CO2 analyser. ṀO2  was measured with a PO2  optode using a stop-flow approach. Injections of known amounts of CO2 into the apparatus yielded accurate and highly reproducible measurements of CO2 content (R(2)=0.997, P<0.001). The viability of in vivo measurements was demonstrated on aquatic dragonfly nymphs (Aeshnidae; wet mass 2.17 mg-1.46 g, n=15) and the apparatus produced precise ṀCO2  (R(2)=0.967, P<0.001) and ṀO2  (R(2)=0.957, P<0.001) measurements; average RER was 0.73±0.06. The described system is scalable, offering great potential for the study of a wide range of aquatic species, including fish.

  9. Effects of Fungicides on Aquatic Fungi and Bacteria

    NASA Astrophysics Data System (ADS)

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

    2005-05-01

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

  10. Evidence for topographic organization in the cerebellum of motor control versus cognitive and affective processing

    PubMed Central

    Stoodley, Catherine J.; Schmahmann, Jeremy D.

    2010-01-01

    Patients with cerebellar damage often present with the cerebellar motor syndrome of dysmetria, dysarthria and ataxia, yet cerebellar lesions can also result in the cerebellar cognitive affective syndrome, including executive, visual-spatial, and linguistic impairments, and affective dysregulation. We have hypothesized that there is topographic organization in the human cerebellum such that the anterior lobe and lobule VIII contain the representation of the sensorimotor cerebellum; lobules VI and VII of the posterior lobe comprise the cognitive cerebellum; and the posterior vermis is the anatomical substrate of the limbic cerebellum. Here we analyze anatomical, functional neuroimaging, and clinical data to test this hypothesis. We find converging lines of evidence supporting regional organization of motor, cognitive, and limbic behaviors in the cerebellum. The cerebellar motor syndrome results when lesions involve the anterior lobe and parts of lobule VI, interrupting cerebellar communication with cerebral and spinal motor systems. Cognitive impairments occur when posterior lobe lesions affect lobules VI and VII (including Crus I, Crus II, and lobule VIIB), disrupting cerebellar modulation of cognitive loops with cerebral association cortices. Neuropsychiatric disorders manifest when vermis lesions deprive cerebrocerebellar limbic loops of cerebellar input. We consider this functional topography to be a consequence of the differential arrangement of connections of the cerebellum with the spinal cord, brainstem, and cerebral hemispheres, reflecting cerebellar incorporation into the distributed neural circuits subserving movement, cognition, and emotion. These observations provide testable hypotheses for future investigations. PMID:20152963

  11. Aquatic Therapy for Children

    ERIC Educational Resources Information Center

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

    2015-01-01

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

  12. Hydrologic Treatments Affect Gaseous Carbon Loss From Organic Soils, Twitchell Island, California, October 1995-December 1997

    USGS Publications Warehouse

    Miller, Robin L.; Hastings, Lauren; Fujii, Roger

    2000-01-01

    Subsidence of organic soils in the Sacramento-San Joaquin Delta, California, has increased the potential for levee failure and flooding in the region. Because oxidation of the peat soils is a primary cause of subsidence, reversion of affected lands to wetlands has been proposed as a mitigation tool. To test this hypothesis, three 10 x 10 meter enclosures were built on Twitchell Island in the Delta and managed as different wetland habitats. Emissions of carbon dioxide and methane were measured in situ from October 1995 through December 1997, from the systems that developed under the different water-management treatments. Treatments included a seasonal control (SC) under current island management conditions; reverse flooding (RF), where the land is intentionally flooded from early dry season until midsummer; permanent shallow flooding (F); and a more deeply flooded, open-water (OW) treatment. Hydrologic treatments affected microbial processes, plant community and temperature dynamics which, in turn, affected carbon cycling. Water-management treatments with a period of flooding significantly decreased gaseous carbon emissions compared to the seasonal control. Permanent flooding treatments showed significantly higher methane fluxes than treatments with some period of aerobic conditions. Shallow flooding treatments created conditions that support cattail [Typha species (spp.)] marshes, while deep flooding precluded emergent vegetation. Carbon inputs to the permanent shallow flooding treatment tended to be greater than the measured losses. This suggests that permanent shallow flooding has the greatest potential for managing subsidence of these soils by generating organic substrate more rapidly than is lost through decomposition. Carbon input estimates of plant biomass compared to measurements of gaseous carbon losses indicate the potential for mitigation of subsidence through hydrologic management of the organic soils in the area.

  13. Mancozeb adversely affects meiotic spindle organization and fertilization in mouse oocytes.

    PubMed

    Rossi, Gianna; Palmerini, Maria Grazia; Macchiarelli, Guido; Buccione, Roberto; Cecconi, Sandra

    2006-07-01

    In this study the effects of mancozeb, a widely used ethylenebisdithiocarbamate fungicide, on mouse oocyte meiotic maturation and fertilization were analyzed. Oocyte cumulus cell-complexes were matured in vitro with or without increasing concentrations of the fungicide (from 0.001 to 1 microg/ml) that, due to its different stability in organic solvents and in water, was resuspended either in dimethyl sulfoxide or in culture medium. Although, about 95% of oocytes reached the metaphase II stage; mancozeb-exposed oocytes showed a dose-dependent increase of alterations in spindle morphology, and this negative effect was more evident when the fungicide was resuspended in culture medium. Under the latter culture condition, oocytes matured in the presence of 0.1 and 1 microg/ml mancozeb showed a significant reduction also in the formation of male and female pronuclei. These results indicate that mancozeb can adversely affect mammalian reproductive performance, likely by perturbing microtubular organization during meiotic maturation.

  14. Quality of fresh organic matter affects priming of soil organic matter and substrate utilization patterns of microbes

    PubMed Central

    Wang, Hui; Boutton, Thomas W.; Xu, Wenhua; Hu, Guoqing; Jiang, Ping; Bai, Edith

    2015-01-01

    Changes in biogeochemical cycles and the climate system due to human activities are expected to change the quantity and quality of plant litter inputs to soils. How changing quality of fresh organic matter (FOM) might influence the priming effect (PE) on soil organic matter (SOM) mineralization is still under debate. Here we determined the PE induced by two 13C-labeled FOMs with contrasting nutritional quality (leaf vs. stalk of Zea mays L.). Soils from two different forest types yielded consistent results: soils amended with leaf tissue switched faster from negative PE to positive PE due to greater microbial growth compared to soils amended with stalks. However, after 16 d of incubation, soils amended with stalks had a higher PE than those amended with leaf. Phospholipid fatty acid (PLFA) results suggested that microbial demand for carbon and other nutrients was one of the major determinants of the PE observed. Therefore, consideration of both microbial demands for nutrients and FOM supply simultaneously is essential to understand the underlying mechanisms of PE. Our study provided evidence that changes in FOM quality could affect microbial utilization of substrate and PE on SOM mineralization, which may exacerbate global warming problems under future climate change. PMID:25960162

  15. Quality of fresh organic matter affects priming of soil organic matter and substrate utilization patterns of microbes

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Boutton, Thomas W.; Xu, Wenhua; Hu, Guoqing; Jiang, Ping; Bai, Edith

    2015-05-01

    Changes in biogeochemical cycles and the climate system due to human activities are expected to change the quantity and quality of plant litter inputs to soils. How changing quality of fresh organic matter (FOM) might influence the priming effect (PE) on soil organic matter (SOM) mineralization is still under debate. Here we determined the PE induced by two 13C-labeled FOMs with contrasting nutritional quality (leaf vs. stalk of Zea mays L.). Soils from two different forest types yielded consistent results: soils amended with leaf tissue switched faster from negative PE to positive PE due to greater microbial growth compared to soils amended with stalks. However, after 16 d of incubation, soils amended with stalks had a higher PE than those amended with leaf. Phospholipid fatty acid (PLFA) results suggested that microbial demand for carbon and other nutrients was one of the major determinants of the PE observed. Therefore, consideration of both microbial demands for nutrients and FOM supply simultaneously is essential to understand the underlying mechanisms of PE. Our study provided evidence that changes in FOM quality could affect microbial utilization of substrate and PE on SOM mineralization, which may exacerbate global warming problems under future climate change.

  16. Quality of fresh organic matter affects priming of soil organic matter and substrate utilization patterns of microbes.

    PubMed

    Wang, Hui; Boutton, Thomas W; Xu, Wenhua; Hu, Guoqing; Jiang, Ping; Bai, Edith

    2015-05-11

    Changes in biogeochemical cycles and the climate system due to human activities are expected to change the quantity and quality of plant litter inputs to soils. How changing quality of fresh organic matter (FOM) might influence the priming effect (PE) on soil organic matter (SOM) mineralization is still under debate. Here we determined the PE induced by two (13)C-labeled FOMs with contrasting nutritional quality (leaf vs. stalk of Zea mays L.). Soils from two different forest types yielded consistent results: soils amended with leaf tissue switched faster from negative PE to positive PE due to greater microbial growth compared to soils amended with stalks. However, after 16 d of incubation, soils amended with stalks had a higher PE than those amended with leaf. Phospholipid fatty acid (PLFA) results suggested that microbial demand for carbon and other nutrients was one of the major determinants of the PE observed. Therefore, consideration of both microbial demands for nutrients and FOM supply simultaneously is essential to understand the underlying mechanisms of PE. Our study provided evidence that changes in FOM quality could affect microbial utilization of substrate and PE on SOM mineralization, which may exacerbate global warming problems under future climate change.

  17. Soil warming affects soil organic matter chemistry of all density fractions of a mountain forest soil

    NASA Astrophysics Data System (ADS)

    Schnecker, Jörg; Wanek, Wolfgang; Borken, Werner; Schindlbacher, Andreas

    2016-04-01

    Rising temperatures enhance microbial decomposition of soil organic matter (SOM) and increase thereby the soil CO2 efflux. Elevated microbial activity might differently affect distinct SOM pools, depending on their stability and accessibility. Soil fractions derived from density fractionation have been suggested to represent SOM pools with different turnover times and stability against microbial decomposition. We here investigated the chemical and isotopic composition of bulk soil and three different density fractions of forest soils from a long term warming experiment in the Austrian Alps. At the time of sampling the soils in this experiment had been warmed during the snow-free period for 8 consecutive years. During that time no thermal adaptation of the microbial community could be identified and CO2 release from the soil continued to be elevated by the warming treatment. Our results which included organic C content, total N content, δ13C, δ 14C, δ 15N and the chemical composition, identified by pyrolysis-GC/MS, showed no significant differences in bulk soil between warming treatment and control. The differences in the three individual fractions (free particulate organic matter, occluded particulate organic matter and mineral associated organic matter) were mostly small and the direction of warming induced change was variable with fraction and sampling depth. We did however find statistically significant effects of warming in all density fractions from 0-10 cm depth, 10-20 cm depth or both. Our results also including significant changes in the supposedly more stable mineral associated organic matter fraction where δ 13C values decreased at both sampling depths and the relative proportion of N-bearing compounds decreased at a sampling depth of 10-20 cm. All the observed changes can be attributed to an interplay of enhanced microbial decomposition of SOM and increased root litter input. This study suggests that soil warming destabilizes all density fractions of

  18. Fermentation condition outweighed truffle species in affecting volatile organic compounds analyzed by chromatographic fingerprint system.

    PubMed

    Tang, Ya-Jie; Wang, Guan; Li, Yuan-Yuan; Zhong, Jian-Jiang

    2009-08-04

    The influences of fermentation conditions and truffle species (i.e., Tuber m