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Project Work Plan

Department of Interior USGS GE PES
Fiscal Year 2012 Study Work Plan

Study Title: Determining Target Salinity Values for Restoration of the Estuaries of the Greater Everglades
Study Start Date: 10/1/06
Revised/Proposed End Date: 9/30/15
Web Sites: http://sofia.usgs.gov/exchange/flaecohist/, http://sofia.usgs.gov/projects/index.php?project_url=salinity_values
Location (Subregions, Counties, Park or Refuge): Everglades National Park, Big Cypress National Preserve, Biscayne National Park, Ten Thousand Islands NWR. Miami-Dade, Monroe, Collier, and Lee Counties, Florida.
Funding Source: GE PES
Other Complementary Funding Source(s): None at this time
Funding History: FY07, FY08, FY09, FY010, FY11, FY12
Estimated Future Funding: FY13, FY14, FY15
Principal Investigator(s): G. Lynn Wingard
Study Personnel: J. Murray, B. Stackhouse, G.L. Wingard; USGS. Frank Marshall, CLF Contractor; Tara Colley, Contractor. Anna Wachnicka (FIU, CESU).
Supporting Organizations: South Florida Water Management District; Biscayne National Park, Army Corps of Engineers, U.S. Fish & Wildlife Service, NOAA
Associated/Linked Studies: Sea Level Rise and Climate: Impacts on the Greater Everglades Ecosystem and Restoration (Wingard, PI); Impacts of Hydrologic and Climatic Change on Greater Everglades Marl Prairies, Marshes, and Sloughs (Willard); Historical Changes in Salinity, Water Quality and Vegetation in Biscayne Bay (ended in FY06); Synthesis of South Florida Ecosystem History Research (ended in FY07); Ecosystem History of the Southwest Coast-Shark River Slough Outflow Area (ended FY09).

Statement of the Problem: The greater Everglades ecosystem of south Florida has undergone a number of anthropogenic and natural changes over the last century. A critical component of the Comprehensive Everglades Restoration Plan (CERP) is to "get the water right". Before restoration can take place, however, it is essential to understand the natural ecosystem as a whole and to comprehend the natural patterns and cycles of change that took place in the system, prior to significant human disturbance. In south Florida, the primary need for historical data has been to understand the natural patterns of flow of freshwater through the wetlands and into the estuaries, and the impact of water control structures built during the 20th-century. Paleoecologic investigations of cores collected throughout the estuaries of south Florida are providing data on historical salinity patterns and providing input to statistical models to predict freshwater flow. The historical perspective of change over decadal to centennial time scales provides the information necessary for land managers to set realistic and sustainable targets and performance measures for restoration and provides an insight into the future of south Florida under various restoration and climate change scenarios.

Objectives: The primary objective of this project will be to provide information to CERP managers (specifically the Southern Coastal Systems Subteam (SCS) of the Regional Evaluation Team of (RECOVER) that can be used to establish target salinity values and performance measures for the estuaries and coastal ecosystems, and to estimate the freshwater stage and flow in the wetlands required to produce historical salinity patterns. This work will build upon previous work in Florida Bay and Biscayne Bay, and information derived from the Ecosystem History Synthesis Project (completed 2007). There are four areas of focus for this task.

  1. Refine our existing modern analog data set by completing analyses of modern samples collected between 1996 and 2011, obtaining additional modern samples where necessary, and applying these improved analog data to core data compiled in the Ecosystem History Synthesis Project.
  2. Collect new cores (if necessary) or examine existing archived cores 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 Coastal Systems Subteam.
  3. Work with our collaborator/contractor, Dr. Frank Marshall, to couple paleosalinity estimates based on the core analyses with linear regression models that can hindcast stage, flow and hydropatterns in the terrestrial Everglades, and salinity in the estuaries, based on equations developed from observed water monitoring station data.

These efforts, when combined with our "Sea Level Rise and Climate: Impacts on the Greater Everglades Ecosystem and Restoration" Project, will ultimately lead to the ability to forecast future changes and develop salinity targets for estuaries for the CERP 2050 Plan that incorporate natural hydrologic relationships and sea-level rise, and take into account future altered conditions under various IPCC scenarios. These data can be used to help select minimum flows and levels for the wetlands. The estuaries of south Florida are not only a "living laboratory of change" but they provide the record of past changes that allow us to forecast the direction of future change.

Specific Relevance to Major Unanswered Questions and Information Needs Identified: 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. This project specifically addresses the needs identified by the Southern Coastal Systems (SCS) Subteam of the Regional Evaluation Team (RET) of RECOVER. The subteam is tasked with establishing performance measures and salinity targets for the estuaries. Project members are serving on the SCS subteam and project results are contributing directly to a revised salinity performance measure that will be part of the next System Status Update.

Specific "major unanswered questions" asked in the DOI Science Plan addressed by this project include:

    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).
  3. Additional Water for Everglades National Park and Biscayne Bay Feasibility Study

  4. "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),
  5. "What are the hydrologic targets needed to mimic historic flows...?" (DOI Science Plan, p. 63).
  6. Biscayne Bay Coastal Wetlands Project

  7. "How much freshwater, and in what seasonal patterns, was delivered historically to Biscayne Bay?" (DOI Science Plan, p. 63)
  8. "What are the links between hydrology and ecology in the Biscayne Bay coastal wetlands?" (DOI Science Plan, p. 64), and
  9. "What are the key indicators of natural ecological response in Biscayne Bay coastal wetlands?" (DOI Science Plan, p. 66)
  10. "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 historical 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.

Specific Relevance to USGS Mission: This project is directly related to the USGS Science Strategy (USGS Circular 1309)–Understanding Ecosystems and Predicting Ecosystem Change. We are investigating the causes and consequences of ecological change and are developing and providing methods for protecting and managing the south Florida Ecosystem–methods that can be applied to other ecosystems around the country and around the world. We are interpreting for the land managers and policy makers how current and future rates of change will affect the natural resources and societal infrastructure of south Florida. In addition, our research contributes directly to the Ecosystems and Climate and Land Use Change mission areas of the USGS. The Draft Ecosystems Science Strategy Plan (in review, 2011) emphasizes the importance of understanding how ecosystems have varied over time, how multiple drivers can impact ecosystems, and the importance of providing tools to inform decisionmaking. In addition, the project contributes significantly to the Climate and Land Use Change Science Strategy by examining the effects of climate and sea-level rise on the south Florida ecosystem over historically significant time periods. Using historical records, we can project future states under various IPCC scenarios and how those scenarios may affect restoration planning.

Highlights and Accomplishments: This project has developed two important tools to allow the Southern Coastal Systems (SCS) subteam of RECOVER to develop salinity targets and performance measures for restoration and the results have contributed significantly to the "wetter Everglades" concept emerging with the Restoration Task Force. Project members and the Project Chief are participating in the establishment of restoration goals for south Florida as part of the RECOVER teams and the NOAA Marine and Estuarine Resource (MARES) Goal Setting effort. In January 2011 the project chief served as the USGS representative at the SCS Salinity Performance Measure workshop. The purpose of the workshop was to determine what models would be used to set performance measures for five regions in the southern estuaries, and the models developed by our project were selected for three of the five, and will be the backup method for the other two. The revised salinity performance measure, based on our project results, will be part of the next System Status Update.

Our methods couple paleoecologic analyses of cores with Linear Regression Models (LRMs) derived from observed meteorologic and hydrologic data that provide seasonal and annual variation. Results indicate that freshwater delivered to the wetlands and estuaries is 2–2.5 times less now than prior to 1900, with the largest deficit during the dry season. In Florida Bay, salinity has increased between 5.3 and 20.1 ppt, with the largest differences in the areas near freshwater outflow points. These results suggest that additional freshwater flows to the Everglades are needed for restoration, particularly near the end of the dry season. Recent modeling efforts in 2011 have determined that the amount of water "lost to tide" (water channeled directly to the marine environment that would have historically entered the freshwater wetlands) is of sufficient volume to reach historical flows and stage if the water is returned to its natural flow path.

Recent Products:

  1. Marshall, F.E. and Wingard, G.L., 2012. Florida Bay salinity and Everglades wetlands hydrology circa 1900 CE: A compilation of paleoecology-based statistical modeling analyses. USGS Open File Report 2012-1054.
  2. Wingard, G.L. and Hudley, J.W., 2011. Application of a weighted-averaging method for determining paleosalinity: a tool for restoration of south Florida's estuaries. Estuaries and Coasts. Released online 9/13/2011. doi: 10.1007/s12237-011-9441-3.
  3. Marshall, F.E.; Wingard, G.L., and Pitts, P.A., 2011. Setting restoration targets in Florida Bay using paleoecology and salinity/hydrology models. National Conference on Ecosystem Restoration. (Baltimore, Maryland) August 1–5, 2011, Abstracts, p. 218.
  4. Murray, J.B. and Wingard, G.L., 2011. Preliminary results from the Schooner Bank Core, Everglades National Park, Florida. National Conference on Ecosystem Restoration. (Baltimore, Maryland) August 1–5, 2011, Abstracts, p. 248.
  5. Stackhouse, B.L. and Colley, T., 2011. Selected molluscan species as tools for restoration of the greater Everglades ecosystem, Florida. National Conference on Ecosystem Restoration. (Baltimore, Maryland) August 1–5, 2011, Abstracts, p. 342.
  6. Marshall, F.E.; Wingard, G.L., and Kemp, S., 2011. A synthesis of linked paleoecological and regression model evaluations to simulate Everglades hydrology and Florida Bay salinity response for CERP restoration performance measures. CERF 2011 Abstracts, p. 134.
  7. Wingard, G.L., 2011. Paleoecologic record of change in Biscayne Bay, Florida, and the role of ecosystem history in restoration decision making. CERF 2011 Abstracts, p. 232.
  8. Wingard, G.L.; Hudley, J.W., and Marshall, F.E., 2010. Estuaries of the Greater Everglades Ecosystem: Long-term Laboratories of Change. U.S. Geological Survey Factsheet 2010-3047.
  9. Wingard, G.L., Stackhouse, B.L., and Project Members, 2010. Ecosystem History of South Florida's Estuaries Database version 5 released December 2010 (available at http://sofia.usgs.gov/exchange/flaecohist/).
  10. Wingard, G.L., in press. Case study: South Florida's estuaries, in Gibson, J. (ed.), Developments in Paleoenvironmental Research. Palaeoestuarine Studies. New York:Springer, 41 msp. Bureau Approval Received 1/11/2010.
  11. Wingard, G.L., 2012. How do we know what the estuaries of south Florida were like in the past? What did south Florida"s estuaries look like in the past? Why is it important to understand the history of an ecosystem...? [three mini-chapters], in Kruczynski, W. and Fletcher, P. (eds.) South Florida Marine Environments: An Ecological Synthesis. Cambridge, Maryland:University of Maryland IAN Press.

Planned Products:

  1. Journal article synthesizing linear regression models and paleosalinity estimates from five sediment cores for Florida Bay.
  2. USGS Open-File Reports on results from individual core analyses to provide data to back up journal article.
  3. Short papers on indicator species and/or results from modern monitoring of species (based data for core analyses).
  4. Synthesis of scientific data on ecosystem history of south Florida's estuaries–conclusion of project.
  5. USGS Circular and fact sheet summarizing the history of south Florida's estuaries in a format that would appeal to the general public and to land managers–conclusion of project.



We have worked with our clients and cooperators to determine priority needs and information gaps. Cores are collected and age models developed for each core using three methods, where possible. Lead-210 analysis establishes the chronology of the upper portions of the cores (see Holmes and others, 2001, for explanation of the methodology). Radiocarbon ages on shells or wood fragments provide data points for the lower portion of the cores. Additional confirmation of the age model comes from pollen of exotic flora with documented dates of introduction into the system. For south Florida, the first occurrence of Casuarina pollen (Australian Pine), an exotic introduced around the beginning of the 20th-century (Langeland, 1990), provides an excellent stratigraphic marker for the early 1900s.

Paleosalinity information is developed by comparing the fauna in the core to a database of modern occurrence of organisms, and statistically deriving a single cumulative weighted percent salinity estimate for each sample in the core (see Wingard and Hudley, 2011). The paleosalinity estimates are used to develop simulated daily salinity patterns adjusted to the NSM, and based on actual climatic patterns. These paleosalinity estimates are then analyzed via linear regression equations developed using modern hydrologic parameters by Frank Marshall (CLF, contractor). Results derived from this method provide values for historical stage, flow and hydropatterns within the Everglades wetlands that would have produced the paleosalinities interpreted from the cores in the southern estuaries of Florida. These results are used directly to develop performance measures and targets for restoration by the Southern Coastal System subteam. Ultimately, we hope to utilize these same methods to forecast different future conditions.

Progress FY 2011

In FY 2011, our proof-of-concept manuscript testing the statistical method of estimating paleosalinity was published in Estuaries and Coasts (Wingard and Hudley, 2011). This paper is important because it demonstrated that the cumulative weighted percent (CWP) method of estimating paleosalinities is accurate within 2 ppt when salinity is averaged over a 2–3 year period; the paper presented results on modern sample analyses where continuous records of salinity were available to test the method, then the application was demonstrated on a core. Project members also delivered five new/revised models to the South Florida Water Management District and Southern Coastal Systems Team of RECOVER. These models couple linear regression models based on current hydrology (developed by Frank Marshall, CLF, contractor) with paleosalinity estimates derived from cores to produce estimates of the historical flow and stage in the wetlands of south Florida and the salinity in the estuaries. (New results from Crocodile Point core and Park Key core, and revised data from Russell Bank, Whipray and Rankin cores were included in the analyses.) An OFR has been prepared and is in review presenting the data from these analyses, and the OFR will be followed by a journal article synthesizing the data from the OFR and discussing the significance of the findings. Results of these analyses were presented at the National Conference on Ecosystem Restoration (Paleoecology session organized by Wingard, Willard, and Bernhardt) and the Coastal and Estuarine Research Federation Conference in 2011.

In addition, to the analytical results, the project has made tremendous progress on two fronts. 1) B.L. Stackhouse has redesigned the project database to make access to faunal count data from field observations readily available. These data will be essential to planned future refinements of the CWP and the hydrologic models. 2) An inventory of all project samples collected in Everglades National Park and Biscayne National Park from 1995 to 2010 has been completed and the data submitted to NPS to fulfill sample cataloging requirement of NPS permits.

Statement of Work FY 2012:

The first priority in FY 2012 will be to complete a journal article synthesizing and discussing the results of the coupled paleosalinity and hydrology regression model analyses of the five Florida Bay sediment cores analyzed in FY 2011. The SCS subteam is currently revising the salinity performance measure from the 2009 Systems Status Report and need a referred journal publication to cite. Our second priority will be to complete reports on several cores analyzed in 2011, but the data have not yet been released. Third, we will begin the process of extracting and compiling an updated modern analog dataset (used for the CWP paleosalinity estimates) using the newly designed database (FY11 product); these findings will be released as digital dataset or in a report format.

Work to be undertaken in future years:

Although this project was originally slated to end in FY 2012, SFWMD, ACOE, USF&W, and NPS have demonstrated a great deal of interest in this project and the continued requests for additional analyses and products from the SCS subteam of RECOVER warrant a continuation of this project. The focus for the last five years has been on Florida Bay, because the SCS's priority was to develop targets and performance measures for this estuary. However, the same types of analyses are needed for Biscayne Bay and the southwest coastal mangrove ecotone as the SCS is requested to develop targets for the other estuaries as well.

Continuation of the project would allow us to apply the same coupled paleo/statistical models developed for Florida Bay to Biscayne Bay and the southwest coast. An improved modern analog base set, used for estimating the paleosalinity from the cores, would need to be developed for these regions. In addition, we hope to be able to incorporate results from the Sea-Level Rise Project to anticipate future salinity and the impact of altered climate and sea level on the estuaries. After completing analyses of all 3 estuarine regions (Florida Bay, Biscayne Bay and the southwest coast) we would then be able to produce two synthesis documents: 1) would compile all of the scientific information we know about the ecosystem history of the estuaries and the freshwater flows required to sustain those historical ecosystems; 2) would be a product aimed at managers and the general public to summarize in layman's terms what the estuaries have looked like in the past and projections about future change.