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Project Summary Sheet

U.S. Geological Survey, Greater Everglades Priority Ecosystems Science (PES) Initiative

Fiscal Year 2004 Study Summary Report

Project Title: Ecological Risk Assessment of Toxic Substances in the South Florida Ecosystem: Wildlife Effects and Exposure Assessment
Project Start Date: FY2000 Project End Date: FY2005
Web Sites:
Location (Subregions, Counties, Park or Refuge): South Florida, Miami-Dade County, ENP, WCA's, Loxahatchee, Big Cypress, STA's
Funding Source: USGS's Greater Everglades Science Initiative (PBS)
Project Personnel: Timothy S. Gross, Sekeenia Haynes, Marisol Sepulveda, Jon Wiebe, Carla Wieser
Supporting Organizations: University of Florida, Florida Fish and Wildlife Conservation Commission
Associated / Linked Projects: Evaluation of infertile alligator eggs and contaminant effects in the South Florida ecosystem (T.S. Gross and K. Rice), Amphibian exposures to atrazine and metamorphic effects in South Florida ecosystems (T.S. Gross and M. Sepulveda), Microcosm and Mesocosm evaluations of OC bioaccumulations in wildlife: development of models for restoration of agricultural properties as wetlands (T.S Gross and St. Johns River Water Management District).

Overview & Objective(s): The primary goal of this project is to assess both the current wildlife contaminant exposures, as well as predict and monitor future restoration-driven exposures. These efforts require a complete food-chain analysis of exposures for biota at all trophic levels, as well as the preliminary monitoring of non-lethal, physiological, effects at multiple levels of biological organization (biochemical to whole animal-2004.

Status: We have conducted a survey of freshwater mussels across 32 sites, alligators across 14 sites, and largemouth bass and sunfish for 42 sites as well as amphibians (frogs and toads at 12 sites) and wading birds (i.e. great egrets) at 5 sites. Efforts have indicated a severe decline in freshwater mussels across sites, especially those with significant habitat alteration/restoration. Altered health status and depressed reproductive/endocrine function is also associated with agricultural exposures and exposure to mercury. Alligator tissues are complete for OC and target contaminant analyses, however, analyses of non-classic/non-target compounds such as pharmaceuticals etc are currently underway. These efforts show significant exposures for alligators in WCA's and other restored/reclaimed sites, as well as exposure to historic and current use agricultural and urban-runoff chemical contaminants. Fish samples have been collected from an extensive collection of sites during the non-reproductive season, mercury analyses are complete and OCP and other contaminant analyses are in progress. Analyses indicate significant exposures and significant distribution differences across S. Florida ecosystems and an altered distribution of mercury, OC's and other contaminants with the implementation of STA's. Fish efforts have been in collaboration with the Florida Fish and Wildlife Conservation Commission and the South Florida Water Management District. All sample analyses and statistical analyses have been completed during FY 2004. Final reports, a dissertation and manuscripts will follow during FY 2005.

Recent & Planned Products: To assess whether chemical contaminants/stressors in South Florida harm wildlife and to evaluate or predict future restoration driven processes and alterations in the distribution, fate and transport or effects of environmental contaminants, we must first complete the proposed assessment of contaminant distribution across trophic levels. All sample analyses and statistical analyses have been completed during FY 2004. Final reports, a dissertation and manuscripts will follow during FY 2005 Results have been presented at the 2003 GEER conference and portions have also be presented at the 2003 and 2004 SETAC conference. Two manuscripts are currently in progress and a PhD student focusing on mercury analyses will complete her degree during mid 2005.

Relevance to Greater Everglades Restoration Information Needs:
The results of this study will be critical to an ecological risk assessment of current contaminant related processes and effects, as well as for the prediction of future restoration-driven effects and alterations. The results thus far, demonstrate significant and varying exposure across sites and exposures which will likely be impacted by restoration processes. In addition, non-lethal, physiological effects are evident and will likely be altered by restoration efforts as well. These results are critical to a eco-risk assessment and to our ability to assess, evaluate and predict restoration-driven effects and should be useful in the development of strategies for minimizing adverse effects of restoration process.

Key Findings:

  1. Significant and varying exposure to contaminants across sites and exposures which is likely to be impacted by restoration processes
  2. Non-lethal, physiological effects are evident and will likely be altered by restoration efforts as well
  3. Contaminant exposures and distributions will be altered significantly by the implementation of restoration, such as the STA's
  4. Effects of water soluble herbicides in amphibians in S. Florida include altered sex differentiation, altered secondary sex characteristics and likely population level effects.

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