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Project Summary Sheet

U.S. Geological Survey, Greater Everglades Priority Ecosystems Science (GE PES) Initiative

Fiscal Year 2007 Study Summary Report

Study Title: Determining Target Salinity Values for South Florida's Estuaries: The Combined Effects of Climate, Sea Level, and Water Management Practices
Study Start Date: 10/1/06 Study End Date: 9/30/2010
Web Sites: http://sofia.usgs.gov/exchange/flaecohist/, http://sofia.usgs.gov/projects/eh_swcsrs/index.html
Location (Subregions, Counties, Park or Refuge): Everglades National Park, Big Cypress National Preserve, Biscayne National Park, Ten Thousand Islands NWR. Monroe, Collier, and Lee Counties, FL.
Funding Source: GE PES
Other Complementary Funding Source(s): None at this time
Funding History: FY07
Principal Investigator(s): G. Lynn Wingard
Study Personnel: T. Cronin, C. Holmes, M. Marot, J. Murray, W.B. Schill, G.L. Wingard - USGS. Contract personnel: R. Ortiz, C. Budet, K. Waylen, and J. Hudley.
Supporting Organizations: South Florida Water Management District; Everglades National Park; Biscayne National Park, Army Corps of Engineers, US Fish & Wildlife Service
Associated / Linked Studies: Historical Changes in Salinity, Water Quality and Vegetation in Biscayne Bay (ended in FY06); Ecosystem History of the Southwest Coast-Shark River Slough Outflow Area, Synthesis of South Florida Ecosystem History Research.

Overview & Objective(s): This task is specifically aimed at addressing needs identified by the Southern Estuaries Subteam of the Regional Evaluation Team (RET) of RECOVER. The Southern Estuaries Subteam is tasked with establishing performance measures and salinity targets for the estuaries and initially the intent was to use the Natural Systems Model (NSM) as the primary basis for the target values. In spring 2005, however, the subteam ran simulations using the NSM for the Initial CERP Update (ICU) that returned salinity values far in excess of any anticipated. They therefore determined that the NSM was not a reliable indicator of near shore salinity patterns, and they have indicated a desire to rely on paleosalinity data to establish targets and performance measures.

The primary objective of this project will be to provide information to CERP managers that can be used to establish target salinity values and performance measures for the estuaries and coastal ecosystems. The information provided will consider the contribution of climate, sea level rise and anthropogenic alteration on salinity values in the estuaries and coastal systems of south Florida. This work will build upon previous work in Florida Bay and Biscayne Bay, and information derived from the Synthesis (Task 6) of these data. There are four areas of focus for this project. 1) Refine our existing modern analog data set by completing analyses of modern samples collected between 1996 and 2004 and applying these improved analog data to core data compiled in the Synthesis Task (Task 6). 2) Collect new cores (if necessary) within the southern estuaries to fill in information gaps identified by the land management agencies (Everglades National Park (ENP) and Biscayne National Park (BNP)), and by the Southern Estuaries Subteam of the Regional Evaluation Team (RET) of RECOVER. 3) Select a few sites in the transition zones to collect cores in a transect moving perpendicular to shore in order to analyze the rate of sea level rise in the region. 4) Work with our collaborators to plug all of the combined paleoecology data into linear regression models that can hindcast salinity for different parts of the system. Ultimately these efforts will lead to the ability to forecast the data and develop targets for the CERP 2050 Plan that take natural change into consideration.

Status: Modern proxy data have been compiled and tested against known salinities and shown to be a reliable indicator of salinity with a correlation coefficient of 0.8 at a 95% confidence level. These results were presented to members of the Southern Estuaries Sub-Team of RECOVER and at the National Conference on Ecosystem Restoration in April 2007. Collaboration on the development of salinity targets with the Southern Estuaries sub-team has continued, and a set of preliminary salinity targets has been developed. The paleosalinity values provided by our project have been successfully used by modelers to hindcast stage height in the terrestrial Everglades; these results also were presented at the National Conference on Ecosystem Restoration in April 2007

We have met with our clients and colleagues several times and discussed priorities for work to be conducted; no clear priorities emerged because all work proposed was considered important, so in FY07 we concentrated on compiling and synthesizing the data we have from the estuaries (overlaps with Synthesis project). Collection of new cores will be postponed until current data analyses are complete. In FY07, we did expand our modern database significantly with nearshore, lower salinity samples.

Recent Products:
Annual Report to Everglades National Park, June 30, 2007, for work performed during 2006.

Wingard, G.L. and Marshall, R., 2007, Setting targets for restoration through integrated science and modeling: A case study from the Greater Everglades Ecosystem: Second National Conference on Ecosystem Restoration, Abstracts, p. 373.

Planned Products:
Collaborative journal articles/reports with the modelers showing the application of paleoecologic data to setting salinity targets

A glossy publication (USGS Circular) summarizing the history of south Florida's estuaries in a format that would appeal to the general public and to land managers

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)

The importance and application of ecosystem history research to restoration goals has been identified in a number of documents. The DOI Science Plan lists as one of the three primary restoration activities the need to “ensure that hydrologic performance targets accurately reflect the natural predrainage hydrology and ecology” (DOI Science Plan, p. 14). The USGS Science Plan for south Florida (2003 draft, msp. 7) identifies five primary science goals, the second of which is to “determine the historical ecological setting of the Everglades.” The primary goal of this project, and related previous ecosystem history projects, is to determine the predrainage hydrology and ecology of critical regions within the estuaries and coastal ecosystems of south Florida, identified by the Southern Estuaries Subteam and other client groups, which have been tasked with setting performance measures and targets for these coastal zones.

This project specifically addresses the needs identified by the Southern Estuaries Subteam of the Regional Evaluation Team (RET) of RECOVER. The Southern Estuaries Subteam is tasked with establishing performance measures and salinity targets for the estuaries and initially the intent was to use the Natural Systems Model (NSM) as the primary basis for the target values. In spring 2005, however, the subteam ran simulations using the NSM for the Initial CERP Update (ICU) that returned salinity values far in excess of any anticipated. They therefore determined that the NSM was not a reliable indicator of near shore salinity patterns, and they have indicated a desire to rely on paleosalinity data to establish targets and performance measures. Coverage of cores in southern Biscayne Bay and northern Florida Bay is limited, however, with each basin having characteristic patterns. We therefore propose to build upon the earlier projects and fill in information gaps identified by the Southern Estuaries Subteam for Florida Bay, Biscayne Bay, and potentially parts of the southwest coastal area.

While the primary goal of this project is to provide data to assist in the establishment of sustainable salinity targets and performance measures, this project also addresses a number of other restoration needs identified in the RFP. The data we gather can be used by the Biscayne Bay Coastal Wetlands Project to assist in developing minimum flows and levels. Our data on the biota present over time and their changes in response to changing water conditions can be used to address questions about natural habitats including the following: 1) the impact of existing and proposed freshwater flows on coastal communities; 2) responses of native organisms to the introduction of exotic species. We will examine the role of climate and sea level rise on changing salinity patterns in the coastal communities, how these natural changes have been over-printed by anthropogenic change, and how sea level and climate should be factored into restoration targets.

A number of specific “major unanswered questions” asked in the DOI Science Plan can be answered by this research. These include the following:

Florida Bay and Florida Keys Feasibility Study

1) “What are the links between freshwater inflows to Florida Bay and the ecology of the bay?” (DOI Science Plan, p. 65)

2) “What is the ecological response to hydrologic change?” (DOI Science Plan, p. 66).

Additional Water for Everglades National Park and Biscayne Bay Feasibility Study

3) “What were the physical and ecological conditions in Shark River and Taylor Sloughs and Biscayne Bay prior to drainage and modification . . .” (DOI Science Plan, p. 63),

4) “What are the hydrologic targets needed to mimic historic flows . . . ? (DOI Science Plan, p. 63).

Biscayne Bay Coastal Wetlands Project

5) “How much freshwater, and in what seasonal patterns, was delivered historically to Biscayne Bay?” (DOI Plan, p. 63),

6) “What are the links between hydrology and ecology in the Biscayne Bay coastal wetlands?” (DOI Science Plan, p. 64), and

7) “What are the key indicators of natural ecological response in Biscayne Bay coastal wetlands? (DOI Science Plan, p. 66)

8) “What are the baseline conditions of the indicators?” (DOI Science Plan, p. 66).

This study supports these CERP projects by 1) conducting research to understand the predrainage hydrology, including the amount, timing and seasonality of freshwater delivered to the estuaries historically; 2) examining the historical environmental conditions, including the linkage between hydrology (water quality and quantity), ecology, and habitats; 3) providing modelers with data on historic conditions in order to set targets and performance measures that reflect natural hydrologic patterns; and 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.

Key Findings: Modern proxy data were tested against known salinities and shown to be a reliable indicator of salinity with a correlation coefficient of 0.8 at a 95% confidence level. These results were presented to members of the Southern Esutaries Sub-Team of RECOVER and at the National Conference on Ecosystem Restoration in April 2007. Collaboration on the development of salinity targets with the Southern Estuaries sub-team has continued, and a set of preliminary salinity targets has been developed. The paleosalinity values provided by our project have been successfully used by modelers to hindcast stage height in the terrestrial Everglades.



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