Project Summary Sheet

Project: Historical Changes in Salinity, Water Quality and Vegetation in Biscayne Bay

Web Sites: http://sofia.usgs.gov/flaecohist/

Location (Subregions & Counties): Southeast coast, primarily Dade County, with some work in Monroe County. Majority of sites within Biscayne National Park.

Funding (Source): 66% OFA from South Florida Water Management District (SFWMD), 34% USGS Place-Based Studies

Principal Investigator(s): G. Lynn Brewster-Wingard, 703-648-5352, lwingard@usgs.gov

Project Personnel: Charles W. Holmes, 727-893-3100, cholmes@usgs.gov; Thomas Cronin, 703-648-6363, tcronin@usgs.gov; Debra Willard, 703-648-5320, dwillard@usgs.gov; Bruce Wardlaw, 703-648-5288, bwardlaw@usgs.gov; Marci Marot, 727-893-3100, mmarot@usgs.gov; James Murray, 703-648-6918, jbmurray@usgs.gov; Robert Stamm, 703-648-5271, rstamm@usgs.gov.

Supporting Organizations: SFWMD, Biscayne National Park

Associated / Linked Projects: Paleosalinity as a Key for Success Criteria in South Florida Restoration

Overview & Status: The objectives of this project are to examine in broad context the historical changes in the Biscayne Bay ecosystem at selected sites on a decadal-centennial scale, and to correlate these changes with natural events and anthropogenic alterations in the South Florida region. Specific emphasis will be placed on historical changes to 1) amount, timing, and sources of freshwater influx and the resulting effects on salinity and water quality; 2) shoreline and sub-aquatic vegetation; and 3) the relationship between sea-level change, onshore vegetation, and salinity. In addition, a detailed examination of historical seasonal salinity patterns will be derived from biochemical analyses of molluscs, ostracodes, foraminifera and corals. The corals will allow us to compare marine and estuarine trends, examine the linkage between the two systems, and will provide precise chronological control. Land management agencies (principally SFWMD, ACOE and Biscayne NP) can use the data derived from this project to establish performance criteria for restoring natural flow, and to understand the consequences of altered flow. These data can also be used to forecast potential problems as upstream changes in water delivery are made during restoration. Project officially began in March 2002. A meeting took place between SFWMD, USGS, NPS and other interested parties on March 20, 2002. Five potential coring sites were identified and a draft-coring plan produced. Coring will take place April 28 and 30th, 2002. Compilation of data from previous Biscayne cores has begun, and biochemical analyses of ostracode shells will begin within the next month.

Needs & Products: Current restoration goals are attempting to restore natural flow of fresh water into Biscayne and Florida Bays and to restore the natural vegetation, but first the question “what was the environment like prior to significant human alteration” must be answered in order to establish targets for restoration. This project is designed to examine the natural patterns of temporal change in salinity, water quality, vegetation, and benthic fauna in Biscayne Bay over the last 100-300 years and to examine the causes of change and provide data that can be used to set targets and performance measures for restoration. Data on individual cores and modern monitoring work will be made available online immediately following completion of analysis at the Ecosystem History Project website http://sofia.usgs.gov/flaecohist/ and the University of Miami stable isotope web site http://mgg.rsmas.miami.edu/groups/sil/index.htm. The University of Miami site also will release oxygen, hydrogen, and carbon isotopic data on South Florida coastal waters collected since 1993. Open-file reports on each core and a synthesis article for a scientific journal will be compiled. A special publication highlighting the research would be prepared for a non-scientific audience, including the stakeholders and the public, and could be made available at Biscayne NP. In addition, results will be reported at scientific meetings, and to client agencies.

Application to Everglades Restoration: The Comprehensive Everglades Restoration Plan (CERP) and the Critical Ecosystem Studies Initiative (CESI) have both identified the importance of understanding freshwater flow into Biscayne Bay and the changes incurred due to alterations in flow. This project directly addresses CESI Task CE1 and CERP Task 3006-7: to "conduct isotopic/paleoecologic studies for the determination of historical salinities/freshwater flows for Biscayne Bay." Data provided also will contribute to CESI Tasks EP1, CE2, and LP2 and CERP Tasks 3007-2, 3, 4 and 3050-5 by contributing to the understanding of the relationships between salinity and the health and distribution of sub-aquatic vegetation and fauna. Tracking changes in onshore vegetation over time will contribute to CESI Task EP1 and CERP Task 3007-9 and data on historical changes in nutrient supply will contribute to CESI Task WQ3 and CERP Task 3090-4. The data provided by this project will evaluate the potential impacts of restoration changes and will provide targets for restoration of historical flow. This will allow the U.S. Army Corps of Engineeers (USACE), the South Florida Water Management District (SFWMD) and other agencies responsible for guiding CERP and CESI to make informed decisions that will protect Biscayne Bay and Biscayne National Park.