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ecological risk assessment of toxic substances in the south florida ecosystem
Project Personnel: Marisol Sepulveda, Jon Wiebe, Carla Wieser, D. Shane Ruessler, Nicola Kernaghan and Beverly Arnold
To assess whether chemical stressors/contaminants in South Florida harm wildlife, it is important to study animals that are potentially exposed and appear sensitive to contaminants. Little is known about the effects of environmental contaminants on invertebrates, however, invertebrate species have been recognized as important environmental sentinels and serve as models for a wide variety of toxicity tests that utilize mortality and lethality as the endpoints of significance. A complete ecological risk assessment requires hazard identification, documentation of adverse effects, demonstration of exposure, and knowledge of dose-response relationships. Evidence of adverse effects, cause and effect relationships, or dose-response relationships has not yet been documented for specific contaminants or mixtures. It is critical that potential exposures and subsequent adverse effects be assessed for wildlife in South Florida to enable a complete ecological risk assessment as well as an assessment and evaluation of proposed restoration strategies.
Results from these studies are expected to provide evidence of significant wildlife exposures to chemical
stressors/contaminants in South Florida and adverse effects as a result of these exposures. Effects characterization will focus on non-lethal effects such as decreased health status, altered reproductive success, and endocrine disruption. In addition, it is likely that we will be able to demonstrate population and community level effects, primarily decreases, for sensitive species in sites with significant hazard of exposure. From the complementary findings of field studies and experimental exposures, we expect to be able to demonstrate convincing evidence as to the causal role of specific chemicals and/or mixtures. Finally, we expect that studies comparing responses of these selected species will provide major insights into the basis of the interspecies differences in sensitivity to contaminants.
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U.S. Department of the Interior, U.S. Geological Survey, Center for Coastal Geology This page is: http://sofia.usgs.gov /projects/eco_risk/index.html Comments and suggestions? Contact: Heather Henkel - Webmaster Last updated: 30 July, 2004 @ 03:02 PM (TJE) |