Project Work Plan

Study Title: Contaminants Synthesis
Study Start Date: 10/01/04 Study End Date: 09/30/06
Web Sites: http://sofia.usgs.gov; http://www.energy.er.usgs.gov (now http://energy.usgs.gov/)
Location (Subregions, Counties, Park or Refuge): Total Ecosystem
Funding Source: USGS Greater Everglades Priority Ecosystems Science (GE PES)
Other Complementary Funding Source(s):
Principal Investigator(s): David P. Krabbenhoft (dpkrabbe@usgs.gov; 608.821.3843), William H. Orem (borem@usgs.gov; 703.648.6273), George R. Aiken (graiken@usgs.gov; 303.541.3036)
Study Personnel: David Krabbenhoft, William Orem, George Aiken
Supporting Organizations: SFWMD, FLDEP, ENP, USFWS, USEPA, BCNP
Associated / Linked Studies: (1) Integrated Biogeochemical Studies in the Everglades (William Orem, borem@usgs.gov, and David Krabbenhoft, dpkrabbe@usgs.gov); (2) Interactions of Mercury with Dissolved Organic Carbon in the Everglades (George Aiken, graiken@usgs.gov)

Overview & Objective(s):

The objective of this project is to produce a synthesis report on contaminants in the Everglades, specifically focusing on the major contaminants of concern: nutrients, sulfur, mercury, and organics. This project links directly to the “Integrated Biogeochemical Studies of Contaminants in the Everglades”, and “Interactions of Mercury with Dissolved Organic Carbon in the Everglades” projects of the GE PES Program, which are the science projects providing the information for this synopsis report project. The project is subdivided into three Tasks. Task 1 will produce a mercury synthesis, with David Krabbenhoft as the lead. Task 2 will concentrate on sulfur and nutrients, with William Orem as the lead. Task 3 will develop the role of dissolved organic carbon (DOC) in methylmercury production, and changes in DOC associated with contaminants entering the Everglades, with George Aiken as the lead.

Specific Relevance to Major Unanswered Questions and Information Needs Identified: (Page numbers below refer to DOI Science Plan.)

This study supports several of the projects listed in the DOI science plan. The study supports the Comprehensive Integrated Water Quality Feasibility Study in the Landscape Science needs of the DOI Science Plan (p. 85), by examining links between water quality and ecosystem structure and function, identifying degraded parts of the ecosystem and quantifying links to contaminants (nutrients, sulfur, organics, and mercury), and investigating the impacts of ASR on the ecosystem. It also addresses risks to wildlife from soil-borne contaminants (sulfur, mercury, organics), through studies of the effects of dry/rewet cycles (Threats Associated with Rehydration of Agricultural Lands, p. 87; Predicting bioavailability of mercury (methylation) following inundation of dry land based on soil and water chemistry, p. 89) on methylmercury formation in STA's. The study supports the Arthur R. Marshall Loxahatchee NWR Internal Canal Structure Project by addressing the impacts of water quality (sulfur/nutrients/mercury) and water management practices on refuge resources, p. 40. The study addresses the Combined Structural and Operational Plan (CSOP) and the Water Conservation Area 3 Decompartmentalization and Sheetflow Enhancement by addressing the potential for increases in toxic contaminant loads (especially sulfur) and its ecological impact, p. 71. Overall, the synthesis report will seek to provide a integrated picture of these critical contaminants in the south Florida ecosystem, but also help to identify possible means toward improving conditions in the future through optimal land management decisions.

Status:

A preliminary draft of the mercury synopsis report is currently being assembled.

Recent Products:

New Project (see Project “Integrated Biogeochemical Studies in the Everglades”, William Orem and David Krabbenhoft, and “Interactions of Mercury with Dissolved Organic Carbon in the Everglades”, George Aiken for related recent products list)

Planned Products:

Mercury Synthesis Report in USGS Publication Form, with mercury-specific chapters addressing mercury cycling processes, geochemistry, and bioaccumulation, sulfur geochemistry effects on mercury cycling and toxicity, and the role of dissolved organic carbon. The volume will be edited by Dave Krabbenhoft, with assistance from William Orem and George Aiken. Several of the chapters are written the lead investigators, but several additional chapters are being drafted by collaborators inside and outside the USGS. A preliminary draft of this synthesis is currently being updated. A final version will be available in late FY05 or early FY06.

WORK PLAN

Title of Task 1: Contaminants Synthesis: Mercury Cycling and Bioaccumulation
Task Funding: USGS Greater Everglades Priority Ecosystems Science (GE PES)
Task Leaders: David Krabbenhoft (dprkabbe@usgs.gov), William Orem (borem@usgs.gov), and George Aiken (graiken@usgs.gov)
Phone: 608-821-3843 (Krabbenhoft)
FAX: 608-821-3817 (Krabbenhoft)
Task Status (proposed or active): active
Task priority: High
Task Personnel: David Krabbenhoft, William Orem, George Aiken

Task Summary and Objectives:

The objective of this task is to produce a synthesis report that focuses specifically focusing on mercury cycling and bioaccumulation in the Everglades. This project links directly to the “Integrated Biogeochemical Studies in the Everglades” (Task 1) project of the GE PES Program, which is the science project providing the information for this synthesis. Data collected from 1995 to the present will be presented and interpreted. The major synthesis report expected from this project will be completed in late FY05 or early FY06. The report will provide a holistic description of the history and evolution of our understanding of the Everglades mercury problem, and how it has interfaced with the Everglades Restoration program. The proposed volume will be a multi-chaptered USGS publication, with the following outline:

• Executive Summary (Krabbenhoft)
• Introductory materials, including: history of the Everglades mercury problem, project goals, interagency collaboration, and a brief description of the Everglades ecosystem and history. (Krabbenhoft)
• Hydrogeological setting and groundwater-surface water interactions in the Everglades ecosystem. (Harvey and King)
• Cycling of sulfur and nutrients in the Everglades ecosystem. (Orem)
• Sedimentary diagenesis in the Everglades ecosystem. (Orem)
• General porewater chemistry in the Everglades ecosystem. (Reddy)
• DOC importance, generation, and evolution in the Everglades ecosystem; Is this the Everglades master variable? (Aiken)
• Mercury in surface waters of the Everglades ecosystem. (Krabbenhoft)
• Mercury methylation in the Everglades ecosystem. (Gilmour)
• Methylmercury degradation in the Everglades ecosystem. (Marvin- Dipasquale)
• Photo-chemistry of mercury in the Everglades ecosystem. (Krabbenhoft)
• Wetting/drying cycles and mercury methylation (Krabbenhoft)
• Delineation of the Everglades ecosystem food webs; the stable isotope approach (Kendall)
• Bioaccumulation of mercury in lower tropic levels of Everglades ecosystem. (Krabbenhoft)
• Bioaccumulation of mercury in predatory fish of the Everglades ecosystem. (Lange).
• The Everglades Mercury Cycling Model. (Harris)
• Summary and Future Directions (Krabbenhoft)

Each of the primary investigators of this project (Krabbenhoft, Orem and Aiken) will be authoring or co-authoring several other synthesis papers in their specific areas of investigation (see below). These publications will take the form of journal papers or USGS reports depending the nature, detail and intended audience of the report.

Work to be undertaken during the proposal year and a description of the methods and procedures:

The major work during FY05 will be the completion of the mercury synthesis report, and associated data bases. This project will principally involve assembling, editing and getting reviews of the individual chapters in the synthesis volume. The challenge will be to develop a document that provides technical information in a form understandable to non-specialists, but without loss of substance. A database will be assembled in support of the synthesis document, so that interested parties wishing to check our conclusions and recommendations will be able to directly examine the data the conclusions were drawn from.

Specific Task Product(s):

Mercury Synthesis Report in USGS Publication Form, with mercury-specific chapters addressing mercury cycling processes, geochemistry, and bioaccumulation, sulfur geochemistry effects on mercury cycling and toxicity, and the role of dissolved organic carbon. Final report expected late FY05 or early FY06). Several other science synthesis reports will also be produced during this effort. David Krabbenhoft will be synthesizing information for two additional reports intended for journal publications, including: (1) a report on photochemical processes regulating mercury speciation and cycling; and (2) a report on bioaccumulation of mercury in lower trophic levels of the Everglades (through Gambusia). These reports are expected to be Direct approved by late FY05 or early FY06. Bill Orem will author a second synopsis report that will bring together nutrient and major ion data collected in the greater Everglades from 1995 to the present. This report is expected in FY06. The report will include information on concentrations of nutrients and major ions in surface water, porewater, soils, and sediments. George Aiken will assemble a manuscript on the overall importance of DOC in regulating the speciation, cycling and bioaccumulation of mercury in the Everglades. This report is expected to be Direct approved by late FY05 or early FY06.