Project Summary Sheet

Study Title: Ecosystem History of the Southwest Coast-Shark River Slough Outflow Area
Study Start Date: 10/1/03 Study End Date: 9/30/08
Web Sites: PUBS ON SOFIA http://sofia.usgs.gov/projects/eh_swcsrs/ and http://sofia.usgs.gov/exchange/flaecohist/
Location (Subregions, Counties, Park or Refuge): Everglades NP, Big Cypress Preserve, Ten Thousand Islands NWR. Monroe, Collier, and Lee Counties.
Funding Source: USGS Greater Everglades Priority Ecosystems Science (PES) Initiative
Annual Costs: FY04; FY05; FY06; FY 07.
Principal Investigator(s): G. Lynn Wingard
Study Personnel: FY07: T. Cronin, C. Holmes, W. Orem, D. Willard, L. Wingard; M. Corum, T. Lerch, M. Marot, J. Murray, T. Sheehan - USGS. C. Budet and R. Ortiz, Contractors.
Supporting Organizations: South Florida Water Management District; Everglades National Park; Big Cypress Preserve, Ten Thousand Islands NWR
Associated / Linked Studies: Historical Changes in Salinity, Water Quality and Vegetation in Biscayne Bay; Paleosalinity as a Key for Success Criteria in South Florida Restoration; Synthesis of South Florida Ecosystem History Research; Integrated Biogeochemical Studies in the Everglades; Determining Target Salinity Values for South Florida's Estuaries.

Overview & Objective(s): One of the primary goals of the Comprehensive Everglades Restoration Plan (CERP) is to restore the natural flow of water through the terrestrial Everglades and into the coastal zones. Historically, Shark River Slough, which flows through the central portion of the Everglades southwestward, was the primary flow path through the Everglades Ecosystem. However, this flow has been dramatically reduced over the last century as construction of canals, water conservation areas and the Tamiami Trail either retained or diverted flow from Shark River Slough. The reduction in flow and changes in water quality through Shark River have had a profound effect on the freshwater marshes and the associated coastal ecosystems. Additionally, the flow reduction may have shifted the balance of fresh to salt-water inflow along coastal zones, resulting in an acceleration of the rate of inland migration of mangroves into the freshwater marshes. The objectives of this project are to document impacts of changes in salinity, water quality, coastal plant and animal communities and other critical ecosystem parameters on a subdecadal-centennial scale in the southwest coastal region (from Whitewater Bay, north to the 10,000 Islands), and to correlate these changes with natural events and resource management practices. Emphasis will be placed on 1) determining the amount, timing and sources of freshwater influx (groundwater vs. runoff) into the coastal ecosystem prior to and since significant anthropogenic alteration of flow; and 2) determining whether the rate of mangrove and brackish marsh migration inland has increased since 20th century water diversion and what role sea-level rise might play in the migration.

Status: Analysis of faunal and floral remains, geochemistry and geochronology of three cores forming a transect up Shark River Slough have been completed and are currently being compiled for a report planned for release in Fall 2007. Age models for the cores have been completed and a database of modern analogue data for nearshore environments has been significantly augmented in FY07, improving our interpretation of the downcore data. Processing of all cores from the southwest coastal area was completed in FY07. Sorting and identification of samples from the Harney River Transect is underway. Open file reports have been produced describing the cores and preliminary interpretations of the depositional environments and part of these data were included in the National Conference on Ecosystem Restoration in April 2007. Time constraints prevented us from beginning the modern sampling collections, work with Florida Gulf Coast University, and analyses of terrestrial wetlands cores. These efforts have been delayed until FY08.

Recent Products:
Orem W.H., Wingard G.L., Holmes C.W., Lerch H.E., Bates A.L., Corum M.D., Beck M.C., and Marot M. (2006) Historical Changes in Carbon, Nitrogen, and Phosphorus in Sediments from Biscayne Bay and Florida Bay. Greater Everglades Ecosystem restoration Meeting, Lake Buena Vista, FL, June 2006, Program and Abstracts.

Schill, W.B., 2006, Assessment Of Historical Ecological Changes Using A Molecular Approach: Greater Everglades Ecosystem Restoration Conference, June 2006.

Wingard, Budet, Hudley, Ecosystem History Database (contains modern and core estuarine data). Released to the public in Spring 2006; release 2 Spring 2007 (http://sofia.usgs.gov/exchange/flaecohist/).

Wingard, G.L., Budet, C.A., and Ortiz, R.E., 2006, Part II: Descriptions and Preliminary Report on Sediment Cores from the Southwest Coastal Area, Everglades National Park, Florida: U.S. Geological Survey Open File Report 2006-1271.

Wingard, G.L., Cronin, T.M., Holmes, C.W., Willard, D.A., Budet, C., and Ortiz, R., 2005, Descriptions and Preliminary Report on Sediment Cores from the Southwest Coastal Area, Everglades National Park, Florida: U.S. Geological Survey, OFR 2005-1360, 28 p. [Available online at http://sofia.usgs.gov/publications/ofr/2005-1360/]

Wingard, G.L. and project members, 2007, Ecosystem History of Florida Bay and the Southwest Coast: Comprehensive Annual Report to Everglades National Park, 141 pp.

Planned Products:
Wingard, G.L., Cronin, T.M., Holmes, C.W., Orem, W., Willard, D.A., Budet, C., Hudley, J.W., Marot, M. and Ortiz, R., 2007, Changes to the Shark River Slough Ecosystem: U.S. Geological Survey OFR and/or Journal Article.

Additional reports and/or journal articles will be generated on the Harney River and Lostmans River Transects as the analyses are completed. A journal article and fact sheets summarizing the findings in the SW coastal area will be produced and information will be presented at national conferences and in meetings with clients.

Specific Relevance to Information Needs Identified in DOI's Science Plan in Support of Ecosystem Restoration, Preservation, and Protection in South Florida (DOI's Everglades Science Plan) [See Plan on SOFIA's Web site: http://sofia.usgs.gov/publications/reports/doi-science-plan/]:

One of the primary DOI activities discussed in the DOI Science Plan is to “ensure that hydrologic performance targets accurately reflect the natural predrainage hydrology and ecology” (DOI Science Plan, p. 14). The primary goal of the Ecosystem History of the Southwest Coast-Shark River Slough Outflow Area study is to determine the predrainage hydrology and ecology of the southwest coastal environment. The Southern Estuaries Sub-Team (SET) of the Regional Evaluation Team (RET) of RECOVER is interested in potential data generated by this study to help set performance measures (PMs) for the Whitewater Bay area. This team includes clients from DOI-NPS, DOI-F&WS, NOAA, ACOE, and SFWMD. Recent data obtained by SET through the simulations run for the Initial CERP Update (ICU) have returned salinity values far in excess of any anticipated; they have therefore turned to our paleosalinity data as the potential primary tool for setting the PMs for the southern estuaries.

Additionally, this study supports the Additional Water for Everglades National Park, the Southern Golden Gate Estates Hydrologic Restoration, and the Southwest Feasibility Study Projects, and it provides information relevant to Landscape Modeling, Invasive Exotic Plant Detection, and Monitoring and Aquatic Exotic Animals Projects. This study supports these projects by 1) conducting research to understand the predrainage hydrology, including the amount, timing and seasonality of freshwater delivered to southwest Florida historically; 2) examining the historical environmental conditions, including the linkage between hydrology (water quality and quantity), ecology, and habitats; 3) providing the modelers with data on historic conditions in order to set targets and performance measures that reflect natural hydrologic patterns; 4) providing long-term historical data on trends and cycles within the biological component of the ecosystem that can be forecasted to predict the effects of implementation of hydrologic restoration on the ecology of coastal communities; and 5) by determining the timing of introduction and spread of exotics in the southwest ecosystem and the coincident changes in the native species.

This study supports the Additional Water for Everglades National Park and Biscayne Bay Feasibility Study by addressing the questions “What were the physical and ecological conditions in . . . Shark River Slough . . .prior to drainage and modification . . .” (DOI Plan p. 63), “What are the hydrologic targets needed to mimic historic flows . . . ? (p. 63).

This study supports the Southern Golden Gate Estates Hydrologic Restoration Project by providing long-term (100-500 years) data on natural hydrologic patterns that can be used to set targets for freshwater inflows (p. 50). In addition, information on long-term changes in the biota and ongoing studies to develop our modern proxy database (used for core interpretation) will provide baseline data on the ecological responses of communities and species (p. 51).

This study supports the Southwest Feasibility Study Project by providing predrainage hydrologic and ecologic conditions that can be used to set the hydrologic targets (p. 50). The results of the core analyses will provide data on temporal and spatial patterns within the estuaries and the linkage between hydrologic conditions and ecological responses; this information can be used by the modelers (p. 50) and to determine what faunal or floral species might be used as key indicators (p. 51).

In addition, the study contributes to the Landscape Modeling project by providing historical ecological data on trends and cycles that can be forecasted to predict the effects of implementation of hydrologic restoration on the ecology of coastal communities. This addresses questions of the impact of increased flow (p. 63), and expected faunal and floral responses (p. 64, p. 79, p. 80). The study also contributes to the Invasive Exotic Plant Detection and Monitoring and Aquatic Exotic Animals Projects by determining the temporal and spatial distribution of exotics and changes in native species coincident with introduction (p. 118).

Key Findings:
Initial examination of cores collected in 2004 indicates a long depositional history (1000-2000 years), slow sedimentation rates, and distinct changes in the environment occurring over time. Preliminary examination of the 2005 cores has provided a model of general patterns of freshwater flow over time for this area. Throughout the time period recorded by the cores, flow to the southwest coastal area has been predominantly through the Shark River channels, diminishing to the north toward the Lostmans River system. The Lostmans system was less influenced by freshwater flow and more emergent than the two systems to the south. The mouths of the river channels have persistently been zones of mixed estuarine environments, with pulses of freshwater periodically reaching the mouth of the Harney and Shark River systems. The lower portions of the mid-system cores from the Harney and Shark Rivers were deposited in freshwater environments, but a change in the system caused a shift towards more estuarine conditions. The core from Roberts River, which empties into Whitewater Bay, shows a clear transition from a freshwater/terrestrial environment near the bottom of the core to a nearshore estuarine environment at the top of the core.