projects > integrated geochemical studies in the everglades
Integrated Geochemical Studies in the Everglades - Mercury Cycling and Bioaccumulation
This project is an integration of a number of individual but interrelated tasks that address environmental impacts in the south Florida ecosystem using geochemical approaches. Externally derived nutrients, mercury and sulfur are three of the most important contaminants currently affecting this ecosystem. Other contaminants of concern include anthropogenically produced organic substances (pesticides, herbicides, polycyclic aromatic and aliphatic hydrocarbons) and other metals. The scientific focus of this project is to examine the complex interactions of these contaminants (synergistic and antagonistic), ecosystem responses to variations in contaminant loading (time and space dimensions), and how imminent ecosystem restoration steps may affect existing contaminant pools. The Everglades restoration program is prescribing ecosystem-wide changes to some of the physical, hydrological and chemical components of this ecosystem. However, it remains uncertain what overall effects will occur as these components react to the perturbations (especially the biological and chemical components) and toward what type of "new ecosystem" the Everglades will evolve. The approaches used will be extensions of previous efforts by the lead investigators, whereby we will enhance our abilities to address land management and ecosystem restoration questions. Major changes implemented in this project will include the use of environmental chambers (controlled enclosures or mesocosums) and isotopic tracers to provide a more definitive means addressing specific management questions, such as "What reductions in toxicity (methylation and bioaccumulation) would be realized if atmospheric mercury emissions were reduced by 75%?" or, "Over what time scales could we expect to see improvements to the ecosystem if nutrient and sulfur loading were reduced by implementation of agricultural best management practices and the storm water treatment areas (STA)?" Results of these geochemical investigations will provide critical elements for building ecosystem models and screening-level risk assessment for contaminants in the ecosystem, and this project will be closely linked with projects addressing ecosystem modeling (Reed Harris, Everglades and TMDL mercury modeling) and risk assessments (Tim Gross, USGS, Gainesville, FL).
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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/int_geochem/index.html Comments and suggestions? Contact: Heather Henkel - Webmaster Last updated: 27 August, 2004 @ 05:40 PM (HSH) |