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Project Work Plan

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

Study Title: Sea-Level Rise and Climate: Impacts on the Greater Everglades Ecosystem and Restoration
Study Start Date: 10/1/09
Study End Date: 9/30/14
Web Sites: Data will be made available at: http://sofia.usgs.gov/exchange/flaecohist/, http://sofia.usgs.gov/projects/index.php?project_url=impacts_slrclim
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: FY10, FY11, FY12.
Estimated Future Funding: FY13, FY14
Principal Investigator(s): G. Lynn Wingard
Study Personnel: C. Bernhardt, T. Cronin, M. Marot, J. Murray, T. Sheehan, B. Stackhouse, G.L. Wingard; USGS. Frank Marshall, CLF Contractor; T. Colley, Contractor.
Supporting Organizations: South Florida Water Management District; Everglades National Park; Biscayne National Park, Army Corps of Engineers, U.S. Fish & Wildlife Service , NOAA, Florida Keys National Marine Sanctuary
Associated/Linked Studies: Determining Target Salinity Values for Restoration of the Estuaries of the Greater Everglades (Wingard); 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: Predictions of sea-level rise of 18–59 cm by the year 2099 were presented in the IPCC Report of 2007, but these estimates excluded contributions from melting glacial ice. Recent estimates presented at the Copenhagen Climate Conference (March 2009) suggest sea level will rise a minimum of 50 cm and probably reach 100 cm or more. These estimates present a significant level of uncertainty for south Florida ecosystem restoration. Almost all of the Greater Everglades ecosystem is less than 5 m above current sea level. A number of factors make south Florida particularly vulnerable to problems associated with rising sea level and global climate change: 1) low elevation; 2) lack of topographic gradient to promote drainage; 3) water table at or near the surface; 4) no upland source of sediment to resupply coast; 5) probability of increasing strength and number of tropical storms; 6) thermal expansion of the oceans (some models show the thermosteric anomalies being greater off the coast of Florida (Plag, 2006)); and 7) the fact that water management practices have reduced freshwater flow during the 20th-century and thus increased the rate of encroachment of saline waters. Long-term tidal gage records show that Florida has been undergoing a 1.9 mm yr-1 increase in relative sea level between 1950 and 2000 (Miller and Douglas, 2006; Plag, 2006). The questions are how does this recent rate of relative sea-level rise compare to pre-anthropogenic rates, has anthropogenic alteration of the south Florida environment increased the impact of rising sea level, and what are the projected future rates under various IPCC scenarios?

In an ecosystem based on the supply of freshwater, and a restoration plan based on "getting the water right", understanding potential impacts of sea-level rise is critical. One of the primary questions that have surfaced in recent CERP team discussions about climate change and sea-level rise is whether restoring more natural flows to the Everglades can restore the ecosystem's natural resiliency. While worrying about the long-term effects of climate change and sea-level rise, CERP project managers are faced with the immediate need to set restoration targets and performance measures. These targets and performance measures need to be attainable and sustainable, but how should attainable and sustainable be defined in the face of global change? Given the range in predictions and the level of uncertainty, what tools do managers have to incorporate sea-level rise into restoration planning? The estuaries of the Greater Everglades provide the perfect living laboratory to study the long-term impacts and implications of sea-level rise on the ecosystem.

Objectives: This project will address the questions of rates and impacts of sea-level rise on the Comprehensive Everglades Restoration Plan (CERP) by utilizing paleoecologic tools and salinity models to examine changes to the Greater Everglades ecosystem over the past 500–3,000 years. Historical rates of change will be compared to potential sea-level rise conditions under different IPCC climate change scenarios. The relationship between sea level, salinity, habitats and biota will be examined, and ecologic indicators of sea-level rise will be identified.

Scientific Objectives:


Management Objectives:

Specific Relevance to Major Unanswered Questions and Information Needs Identified: The importance and application of studying the impacts of sea-level rise on restoration of the south Florida ecosystem has been identified in a number of documents. The DOI Science Plan (p. 79) lists "understanding the effects of sea-level rise"; as research that needs to be conducted "to assess the current and historical relationships between sea level, salinity, overland freshwater flows, tidal regimes, water budgets, and climate on mangrove and oligohaline communities." The plan further identifies an information gap in understanding the "response of coastal communities to simultaneous effects of increased freshwater flows and sea-level rise." The analysis of paleoecologic data proposed here, and the linkage to models that determine the relationships between freshwater stage and flow in the wetlands and salinity in the estuaries, provides the longer term historical perspective necessary to predict future effects of sea-level rise on the physical and biological components of the ecosystem and the interplay of restoration efforts and global changes.

The DOI Science Plan (p. 89–90) also identifies a need for "models that simulate how restoration projects will alter the hydrology of Florida Bay" and the related effects of sea-level rise. The linear regression models that we are developing in this and a related project (Determining Target Salinity Values for Restoration of the Estuaries of the Greater Everglades) provide the tools necessary to relate stage and flow directly to salinity using empirical data, and these models can be used to estimate future sea-level rise effects. Sea-level rise is considered a component of adaptive management under CERP Landscape Monitoring and Assessment (p. 94, 104) and detecting "early ecological responses to changes in sea-level" is identified as needed science. The faunal and floral analyses of cores proposed in this study provide centennial scale response patterns and change-detection to fulfill these science needs.

Further indication of the importance of this issue to the south Florida restoration effort is the Miami-Dade Climate Task Force and the four county Southeast Florida Regional Climate Change compact. The primary concern of these local coalitions is sea-level rise. Restoration must include and continue to provide safety and protection for the citizens of south Florida, and this issue becomes even more significant in the face of sea-level rise, a point made by the South Florida Natural Resources Center of NPS in their brochure "Climate Change and South Florida's National Parks".

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 the response of the biological components of the south Florida ecosystem to changes in sea level. A primary goal of the work is to provide policymakers with information on how the current and future rates of change will impact the natural and human resources of south Florida. The work also examines the relationship between biodiversity and migration of ecotones in response to sea level and climate changes, and addresses the Climate and Land Use Change Science Strategy by examining these relationships 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.

In addition, we are addressing the science theme of Hazards by assessing "the vulnerability of national parks and wildlife refuges along the Nation's coasts to sea-level rise and coastal change" (p. 33). Also, the knowledge we are gaining about rates of sea-level rise and interaction with the biota of south Florida can be used to understand the impacts on other regions of the southeastern United States as well. Finally, our work will shed light on the theme of Water Availability by examining the impact of sea-level rise on freshwater supply and the interaction of these factors with climate.

Highlights and Accomplishments: Project members Deb Willard and Christopher Bernhardt have synthesized the last 7,000 years of sea-level rise information for the Greater Everglades ecosystem by examining data from existing cores. They have found that freshwater peats began to accumulate 6,000–7,000 years ago, under present day Florida Bay, when sea level was approximately 6.2 m below its current position. Around 3,000 years ago, sea-level rise slowed and the south Florida coastline stabilized. During the last 2,000 years south Florida was impacted by regional and global-scale changes in sea level and climate. Around 1,000 years ago, estuarine muds are intercalated with mangrove peats, indicating a slowing or still-stand of sea level. A component of this effort is a compilation of the radiocarbon dates on basal peat samples from cores throughout the south Florida region. This work was conducted in conjunction with Impacts of Hydrologic and Climatic Change on Greater Everglades Marl Prairies, Marshes, and Sloughs (Willard, PI).

Project members participated in sea-level rise workshop in south Florida (2/2011) and organized sessions on sea-level rise for the National Conference on Ecosystem Restoration (8/2011) and for the Coastal and Estuarine Research Federation Conference (11/2011). Preliminary results from compilation of southwest coastal area show significant changes in rates of sea-level rise, climate and freshwater supply along the southwest coastal area over the last 6,000–7,000 years. Changes in these variables have produced shifts in species composition over time, and the migration of the vegetation zones has tracked sea-level changes throughout this time period. Past shifts in species mark transition periods, followed by periods of relative stability in species composition.

Recent Products:
Wingard, G.L.; Lorenz, J., and Smith III, T.J., in review. Conceptual ecological model of southwest Florida's coastal wetlands, 25 msp.: Chapter in Nuttle, W. ed., MARES Integrated Conceptual Ecological Models.

Cronin, T.M.; Wingard, G.L.; Dwyer, G.S.; Swart, P.K.; Willard, D.A., and Albeitz, J., in press, Climate variability during the medieval climate anomaly and Little Ice Age based on ostracode faunas and shell geochemistry from Biscayne Bay, Florida. In Ostracoda as Proxies for Quaternary Climate Change: Developments in Quaternary Science series. Amsterdam, The Netherlands: Elsevier Publishing, 400p.

Willard, D.A. and Bernhardt, C.E., 2011, Impacts of past climate and sea-level change on Everglades wetlands: placing a century of anthropogenic change into a late-Holocene context: Climate Change, v. 107, pp. 59-80.

Murray, J.B.; Pierce, H., and Wingard, G.L. 2011, Preliminary results of ground penetrating radar survey at the mouth of the Harney River, southwest coastal region, Everglades National Park, Florida: CERF 2011 Abstracts, p.151

Wachnicka, A.; Gaiser, E.; Briceno, H., and Wingard, G.L. 2011. Late Holocene changes in diatom communities in south Florida estuaries caused by climate variability and anthropogenic alterations of watershed on the south Florida mainland: CERF 2011 Abstracts, p. 222

Wingard, G.L.; Willard, D.A., and Bernhardt, C.E., 2011, Potential impacts of climate change and sea-level rise on south Florida's coastal wetlands: National Conference on Ecosystem Restoration, (Baltimore, Maryland) August 1–5, 2011, Abstracts, p. 394

Murray, J.B. and Wingard, G.L., 2010, Using floral and faunal assemblages and observed habitat associations to monitor sea-level rise in the Shark and Harney River Basins of southwest Florida: GEER 2010 Abstracts, p. 215 [http://www.conference.ifas.ufl.edu/geer2010/pdf/abstracts.pdf]

Wingard, G.L., 2010. contributed text on sea-level rise and climate change impacts on south Florida to the NOAA sponsored MARES (Marine and Estuarine Goal Setting for south Florida: Integrated Conceptual Ecosystem Model for the Florida Keys/Dry Tortugas Marine Ecosystem: NOAA Technical Report, 2012. Miami, Florida: Atlantic Oceanographic and Meteorological Laboratory.

Planned Products:

  1. Bernhardt, C. Age model results from a series of sediment cores collected in southwestern Everglades National Park.
  2. Report on cores from the southwest coastal mangrove ecotone, examining the position of sea level over the last 2,000 years and impacts on species composition.
  3. Journal articles on analyses of cores, rates of change, application of models, etc.
  4. Journal articles on the response of organisms to changes in sea level over biologically significant time periods.

B. WORK PLAN

Methodology:

Project is utilizing cores, samples and data collected under previous Ecosystem History Projects in initial phases of study. A series of cores have been collected beginning in 1994 from south Florida. These cores contain a record of the environment of deposition, and most have been radiometrically dated (http://sofia.usgs.gov/publications/ofr/2007-1203/index.html). Basic principles of paleoecology are utilized to interpret the biotic assemblages in the individual core samples. Data from modern sites collected in south Florida since 1995 are used to determine ecological preferences of different biotic groups (primarily plants, mollusks, and ostracodes). Comparison of the living biota to the core assemblage data allows us to determine the environment at the time of deposition, including the range of salinities that existed, approximate water depth, and availability of freshwater. (See Brewster-Wingard and others, 2001; Cronin and others, 2001; Ishman and others, 1998; Willard and others, 2001a and 2001b; and Wingard and others, 2003 and 2004 for examples of paleoecologic studies in south Florida.)

This project focuses on the position of sea level and water depth over time, as indicated by the biotic assemblages and sedimentological characteristics of the cores. Transects of cores up Shark River Slough, Harney River and Lostmans River, will allow us to examine the position of the saltwater–freshwater interface along a gradient over time. Cores from the bays will examine impacts to the more open systems. In addition, stable isotopic analyses may be used to determine contributions of freshwater versus seawater to the depositional record. Results of the biotic analyses will be compared to maps of the distribution of coastal sediments, vertical and horizontal movement of environmental facies over time, and tidal gage records.

Progress FY 2011: A preliminary synthesis of existing information on the southwest coast was prepared and indicated interesting correlations between sea-level rise, climate, freshwater flow and shifts in species composition. Based on these results, we have identified information gaps. Peat cores were collected in FY11 to look at synchronous marsh/slough changes along the Shark River Slough region, under C. Bernhardt's permit. Work in the rivers and estuaries was delayed in 2011 because project needed to complete sample inventory, prior to renewal of NPS permit. A publication on age models for the cores is nearly complete. Project members participated in a Sea-Level Rise Workshop in south Florida in February 2011, and coordinated several sessions on sea-level rise at the National Conference on Ecosystem Restoration in August 2011 and at the Coastal and Estuarine Research Federation Meeting in November 2011.

A novel use of GPR (ground penetrating radar) was tried in 2011 to see if we could pick up signals of paleo-oyster mounds off shore from Shark River and Harney River cores. These mounds would help identify paleoshorelines and changes in sea level. The method is not supposed to work in saline water, but we were able to locate the mounds, and conducted a ground-truthing exercise to verify GPR results. Results of this experimental method were presented at the Coastal and Estuarine Research Conference in 2011.

In addition, the Project Chief is serving as a Co-PI on a NOAA led Marine and Resource (MARES) Goal Setting for South Florida Project, and has taken the lead in writing the conceptual ecological model for the wetlands of the southwest coast of Florida. The impacts of sea-level rise on the unique mangrove coast ecosystem of south Florida is of particular concern to Everglades National Park and the NOAA group.

Statement of Work FY 2012: Our first priority in FY12 will be to complete the age model report. This will allow us to determine if additional cores will be needed to supplement the existing set, and will provide the foundational data for analysis of the Shark River Slough and Harney River transects. If new cores are needed, we will apply to the park for permission to collect cores along a transect in the southwest coastal area (Shark River and Harney River) to supplement the earlier cores collected in 2004 and 2005. Reports on the 2004–2005 transect cores are scheduled for completion in 2012. Project Chief Lynn Wingard will continue to provide information to the NOAA MARES group and the Southern Coastal Systems RECOVER group on issues of sea-level rise. This work will be conducted in conjunction with Impacts of Hydrologic and Climatic Change on Greater Everglades Marl Prairies, Marshes, and Sloughs (Willard/Bernhardt, PI).

Work to be undertaken in future years: Future years will focus on analyses of any new cores collected in FY12 and on comparing and synthesizing those results with compilation of core data from all over south Florida. One product will be to develop various future scenarios using Frank Marshall's linear regression models to predict future salinities under various IPCC scenarios. Rates of sea-level rise will be estimated for south Florida, and compared to IPCC projections of future rates. Maps will be developed illustrating the migration of key species assemblages over time in response to changing salinity patterns and sea-level position.