Progress 08/15/01 to 06/30/06
Outputs
This research characterized the fate and effects of metals and pesticides in the surface waters of South Carolina. During this project we systematically characterized the influence of surface water chemistry on the bioavailability and toxicity of metals to aquatic organisms. We have worked with copper, nickel, zinc, and silver. These metals are common contaminants in either nonpoint source runoff or in point source discharges. We have quantified the influence of water hardness, alkalinity, pH, Na, and dissolved organic carbon on metal toxicity. Our research has laid the foundation for the development of predictive models that the US EPA will use to generate site-specific water quality criteria. In addition, we have begun to characterize the mechanisms of recovery for organisms that have experiences non-lethal copper exposures. Pesticide research has focused on quantifying the behavioral impacts of sublethal diazinon exposures in fish. We have been able to
quantitatively relate biochemical changes in acetylcholinesterase activity to ability to capture prey. These data have significant fish population implications.
Impacts
The US Environmental Protection Agency is using our research (along with many others) to develop site-specific water quality criteria for metals. This research has laid the toxcological foundation for development of the Biotic Ligand Model.
Publications
- Zahner, H.M., E. Vangenderen, J. Tomasso, S. J. Klaine. 2006. Whole-body sodium concentration in larval fathead minnows (Pimephales promelas) during and following copper exposures. Environ. Toxicol. Chem. 25(6):1635.
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Progress 01/01/05 to 12/31/05
Outputs
Research during 2005 focused on finalizing our research on the influence of water quality parameters on copper toxicity to aquatic organisms and continuing our research on the response of aquatic organisms to episodic metal exposure. Results of the influence of water quality on copper toxicity research indicate that dissolved organic carbon and alkalinity have more influence on copper toxicity than water hardness. Classically, water hardness has been the only water quality parameter considered in determining copper water quality criteria in surface waters. Our research on the response of aquatic organisms to episodic metal exposure focused on copper, zinc, cadmium, arsenic and selenium. In general, our results indicate that aquatic organisms can tolerate high metal concentrations if the duration of exposure is short enough. Further, for Cu and Zn, the effect of multiple exposures was inversely related to the recovery time between exposures. A mathematical model has
been developed to describe the influence of exposure concentration, duration, and frequency on metal toxicity to the water flea, Daphnia magna. This model has been calibrated for copper, zinc, and selenium.
Impacts
Results of our copper toxicity work have resulted in the refinement of the Biotic Ligand Model that is currently being adopted by the US Environmental Protection Agency for site specific water quality criteria for copper in surface waters.
Publications
- VanGenderen, E.J., A.C.Ryan, J.R.Tomasso and S.J.Klaine. 2005. Copper toxicity to Pimephales promelas in soft surface water. Environmental Toxicology and Chemistry 24(2): 408-414
- Bielmyer, G.K., D. Gatlin, J.J. Isley, J. Tomasso, and S.J. Klaine. 2005. Responses of hybrid striped bass to waterborne and dietary copper in freshwater and saltwater. Comparative Biochemistry and Physiology Part C: Toxicology and Pharmacology 140(1): 131-137.
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Progress 01/01/04 to 12/31/04
Outputs
We have characterized the influence of water quality on the toxicity of copper and zinc to aquatic organisms. Results of this research are in the publications listed below. During 2004 we have begun to fucus on the response of aquatic organisms to episodic metal exposure This research is esential to reducing the uncertainty associated with ecological risk assessments of metals in aquatic ecosystems. Most metal exposures in the environment are not continuous. Rather, exposures to aquatic organisms vary in duration, intensity and frequency. Traditional aquatic toxicity research has focused on responses to very stable contaminant exposures. Our research is focusing on responses of aquatic organisms to these episodic exposures. Further, we are characterizing recovery of organisms following sublethal copper exposures. Results to date indicate that aquatic organisms recover from copper exposures in excess of water quality criteria as long as these exposures are of short
duration. Whole body sodium is a good physiological marker of copper stress as well as recovery in fathead minnows (Pimephales promelas).
Impacts
Research results will allow regulators in SC to better predict copper toxicity in surface waters and aid in the development of site-specific water quality criteria.
Publications
- Bielmyer, G. K., S.J. Klaine, J. Tomasso, W.R.Arnold. 2004. Changes in Water Quality After Addition of Sea Salts to Fresh Water. Chemosphere 57, 1707-1711.
- Ryan, A., J. Tomasso, S.J. Klaine. 2004. Influence of Natural Organic Matter Source on Copeer Toxicity to Larval Fathead Minnows (Pimephales promelas): Implications for the Biotic Ligand Model. Environmental Toxicology and Chemistry 23(6):1567-1574.
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Progress 01/01/03 to 12/31/03
Outputs
Further research has been conducted to characterize the influence of surface water quality on copper toxicity. Based on laboratory results with fathead minnows (Pimephales promelas) in 96h static bioassays, the toxicity of copper can be predicted as follows: 96-h LC50 = -54.62 (DOC) + -224 (DOC/H) + 12.53 (DOC*pH) where LC50 is the concentration that kills 50% of the organisms in 96 h; DOC is dissolved organic carbon in mg/l; H is hardness in mg/l as CaCO3; and pH is in units. This model predicted 88% of the variation in the factorially design laboratory experiment. In addition, it predicted over 60% of the variation in an independent copper toxicity data set generated from natural surface waters throughout SC. Future spatial analysis of the surface water data will allow us to discriminate copper toxicity data among watersheds and ecoregions. We have also characterized the response of water fleas (Daphnia magna) to episodic exposure to copper in an effort to better
predict the effects of both point source and nonpoint source discharges on aquatic organisms. Results suggest that Cu toxicity is a function of duration, magnitude and frquency of exposure. It is critical to characterize recovery time post exposure in order to predict the effect of the next pulsed exposure. We are exploring using whole body socium to determine recovery from copper exposure.
Impacts
Research results will allow regulators in SC to better predict copper toxicity in surface waters and aid in the development of site-specific wqater quality criteria.
Publications
- VanGenderen, E.J., A.C.Ryan, J.R.Tomasso and S.J.Klaine. 2003. Influence of Dissolved Organic Matter Source on Silver Toxicity to Pimephales promelas. Environmental Toxicology and Chemistry in press.
- Long, K.E., E.J.VanGenderen, and S.J. Klaine. 2004. The Effects of Low Hardness and pH on Copper Toxicity to Daphnia magna. Environmental Toxicology and Chemistry 23(1):72-75.
- Hoang, T.C., J.R. Tomasso, S.J. Klaine. 2004. Influence of water quality parameters on the toxicity of nickel to Pimephales promelas. Environmental Toxicology and Chemistry 23(1):86-92.
- Bielmyer, G. K., J. Tomasso, S.J. Klaine. 2004. Physiological Responses of Hybrid Striped Bass to Aqueous Copper in Freshwater and Saltwater. Aquatic Toxicology Submitted for Review.
- Ryan, A., J. Tomasso, S.J. Klaine. 2004. Influence of Natural Organic Matter Source on Copeer Toxicity to Pimephales promelas. Environmental Toxicology and Chemistry. Accepted for Publication.
- VanGenderen, E.J., A.C.Ryan, J.R.Tomasso and S.J.Klaine. 2004. Copper toxicity to Pimephales promelas in soft surface water. Environmental Toxicology and Chemistry Submitted for publication.
- Sciera, K.L., J.J. Isely, J.R. Tomasso, S.J. Klaine. 2004. Influence of Multiple Water Quality Characteristics on Copper Toxicity to Fathead Minnows (Pimephales promelas). Environmental Toxicology and Chemistry Submitted for publication.
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Progress 01/01/02 to 12/31/02
Outputs
During the last 12 months the focus of this research has been to characterize the factors controlling copper bioavailability to aquatic organisms. We have sample waters throughout South Carolina and conducted copper toxicity tests with fathead minnows (Pimephales promelas) in these waters as well as laboratory waters that were matched to field samples in hardness, alkalinity and pH. This facilitated the development of water effect ratios (WER). WER values greater than 1 suggest that protective effects exist in the surface waters that are not accounted for in the laboratory bioassays. All sites had WER values greater than 1. This means that current water quality criteria for copper may be overprotective in SC surface waters. We conducted a compete factorially designed experiment that examined the interactive effects of pH, hardness, dissolved organic carbon concentration, and natural organic matter source on the toxicity of copper to fathead minnows. Results confirmed
that hardness, DOC and pH were controlling copper bioavailability. NOM source had no significant influence on copper toxicity. The relationship among the variables changed depending on pH. Hence, two models were developed to describe the data: For pH < 7 the dissolved Cu LC50 = 26.07+0.72(DOC2)-350.36(H-1); r2 = 0.8698; for pH > 7 the dissolved Cu LC50 = 138.76+82.49sqrt(DOC)-2243.36(H-1); r2 = 0.7689.
Impacts
Results of our research are being utilized by state and federal regulatory agencies to help determine site-specific water quality criteria for copper. In addiiton, we are working with the developers of the Biotic Ligad Model to make that model more useful in the low hardness waters of the Southeast US.
Publications
- No publications reported this period
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