Project Summary Sheet

Project: Paleosalinity as a Key for Success Criteria in South Florida Restoration

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

Location (Subregions & Counties): Southeast region, Monroe County, primarily within Florida Bay, Everglades National Park

Funding (Source): USGS Place-Based Studies

Principal Investigator(s): Bruce Wardlaw, 703-648-5288, bwardlaw@usgs.gov

Project Personnel: G. Lynn Brewster-Wingard, 703-648-5352, lwingard@usgs.gov; Thomas Cronin, 703-648-6363, tcronin@usgs.gov; Robert Stamm, 703-648-5271, rstamm@usgs.gov; James Murray, 703-648-6918

Supporting Organizations: South Florida Water Management District, Everglades National Park, Army Corps of Engineers

Associated / Linked Projects: Historical Changes in Salinity, Water Quality and Vegetation in Biscayne Bay (Current); Ecosystem History of Florida Bay (Completed)

Overview & Status: The objectives of this project are to 1) test and develop the methodology for extracting water chemistry information from selected calcareous shelled animals that grow within the water; 2) develop an understanding of the biology of the selected organisms so that the water chemistry data extracted from the shells can be put in temporal context; and 3) to apply this information to shells found in soft sediment cores that span the last 100-300 years of South Florida history in order to determine the seasonal variation in salinity and water sources prior to significant human alteration of the environment. These data will provide land managers with the necessary information to establish targets and performance measures as restoration of more natural timing and delivery of water proceeds.

A test comparison of instruments (SHRIMP, laser ablation, and ion microprobe) has been completed in FY02 and the ion microprobe has been selected as the best instrument for the metal elemental analyses of the shells. Growth experiments in the field and the laboratory are proceeding, and selected organisms showing growth have been removed and prepared for analyses on the microprobe. Analyses of these shells are currently proceeding. Data from the analyses will be correlated to salinity and temperature data from the growth sites to calibrate the shell chemistry data to water chemistry. Organisms from cores in Florida Bay at Russell Bank, Dragover, Bob Allen, Whipray, and Rankin have been selected for analyses and are in the process of being prepared for sectioning. A report on the methodologies and calibration will be completed within FY02.

Needs & Products: In order for the ACOE and SFWMD to develop a hydrodynamics model of flow, and to restore natural flow to the greater Everglades ecosystem, an understanding of seasonal patterns of flow, and sources of water prior to water management practices is necessary. This project will use changes in seasonal salinity over the last 100-200 years to develop a means for predicting expected salinity ranges at specific sites following a given period of monthly rainfall. These data can serve as targets for restoration success criteria in terms of restoring a natural link between monthly rainfall and freshwater influx into the estuarine systems. Data and information will be made available in report format, online at our web site (http://sofia.usgs.gov/flaecohist/) and through meetings and talks with client agencies.

Application to Everglades Restoration: The most critical issue in the restoration of the south Florida ecosystem is "to get the water right." More natural patterns of freshwater flow through the terrestrial ecosystem and into the estuaries and coastal areas must be restored; this includes timing, quantity and quality of the water delivered. In order to recreate these natural flow patterns it is essential to understand the natural patterns of variation in the predevelopment system and the sources of water. Seasonality of water delivery is critical to the reproductive cycles of many of the organisms within the environment. This study is designed to test a methodology for determining seasonal patterns of change in waters from historic and prehistoric times, thereby providing SFWMD.