Projected Reorganization of Florida Bay Seagrass Communities in Response to the Increased Freshwater Inflow of Everglades Restoration
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Historic changes in water-use management in the Florida Everglades have caused the quantity of freshwater inflow to Florida Bay to decline by approximately 60% while altering its timing and spatial distribution. Two consequences have been (1) increased salinity throughout the bay, including occurrences of hypersalinity, coupled with a decrease in salinity variability, and (2) change in benthic habitat structure. Restoration goals have been proposed to return the salinity climates (salinity and its variability) of Florida Bay to more estuarine conditions through changes in upstream water management, thereby returning seagrass species cover to a more historic state. To assess the potential for meeting those goals, we used two modeling approaches and long-term monitoring data. First, we applied the hydrological mass balance model FATHOM to predict salinity climate changes in sub-basins throughout the bay in response to a broad range of freshwater inflow from the Everglades. Second, because seagrass species exhibit different sensitivities to salinity climates, we used the FATHOM-modeled salinity climates as input to a statistical discriminant function model that associates eight seagrass community types with water quality variables including salinity, salinity variability, total organic carbon, total phosphorus, nitrate, and ammonium, as well as sediment depth and light reaching the benthos. Salinity climates in the western sub-basins bordering the Gulf of Mexico were insensitive to even the largest (5-fold) modeled increases in freshwater inflow. However, the north, northeastern, and eastern sub-basins were highly sensitive to freshwater inflow and responded to comparatively small increases with decreased salinity and increased salinity variability. The discriminant function model predicted increased occurrences of Halodule wrightii communities and decreased occurrences of Thalassia testudinum communities in response to the more estuarine salinity climates. The shift in community composition represents a return to the historically observed state and suggests that restoration goals for Florida Bay can be achieved through restoration of freshwater inflow from the Everglades.
KeywordsEcosystem restoration Florida Bay Everglades Benthic habitat Seagrass Water quality Salinity Hydrology Modeling
The monitoring programs that supplied vital benthic habitat data for this effort included the South Florida Water Management District/Miami-Dade County Department of Environmental Resources Management funded monitoring program, the Florida Keys National Marine Sanctuary funded by grants from NOAA’s South Florida Program (contract NA06NOS4780105) and the US EPA (Assistance Agreement X797468102), and Florida Department of Environmental Protection’s Fish Habitat Assessment Program funded by Florida DEP, USGS Biological Resources Division, and Everglades National Park. Funding for analyses were provided by grants from Everglades National Park, Critical Ecosystems Studies Initiative (Cooperative agreement 1443CA528001022), and Florida Sea Grant (SI-08-33). Water quality data were made available by J.N. Boyer at Florida International University. Further support was provided by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Grant No. DBI-0620409 and Grant No. DEB-9910514. This is publication number 514 from the Southeast Environmental Research Center at FIU.
- Butler IV, M.J., J.H. Hunt, W.F. Herrnkind, M.J. Childress, R. Bertelsen, W. Sharp, T. Matthews, J.M. Field, and H.G. Marshall. 1995. Cascading disturbances in Florida Bay, USA: Cyanobacterial blooms, sponge mortality, and implications for juvenile spiny lobsters Panulirus argus. MEPS 129: 119–125.CrossRefGoogle Scholar
- Chester, A.J., and G.W. Thayer. 1990. Distribution of spotted seatrout (Cynoscion nebulosus) and gray snapper (Lutjanus griseus) juveniles in seagrass habitats of western Florida Bay. Bulletin of Marine Science 46: 345–357.Google Scholar
- Cosby, B.J., W.K. Nuttle, and J.W. Fourqurean. 1999. FATHOM: Model description and initial application to Florida Bay, project completion report. Washington, D.C.: National Park Service, U.S. Dept. of Interior.Google Scholar
- Cosby, B., W. Nuttle, and F. Marshall. 2005. FATHOM enhancements and implementation to support development of MFL for Florida Bay. Final report on contract C-C-15975-WO05-05 for the South Florida Water Management District. New Smyrna Beach: Environmental Consulting & Technology.Google Scholar
- Hansen, M., and N.T. DeWitt. 2000. 1890 and 1990 bathymetry of Florida Bay. U.S. Geological Survey Open File Report 00-347.Google Scholar
- Hittle, C., E. Patino, and M. Zucker. 2001. Freshwater flow from estuarine creeks into northeastern Florida Bay. U.S. Geological Survey Water-resources Investigations Report 01–4164. Tallahassee: U.S. Geological Survey.Google Scholar
- Hobbie, J.E. 2000. Estuarine science: The key to progress in coastal ecological research. In Estuarine Science: A synthetic approach to research and practice, ed. J.E. Hobbie, 1–11. Washington, D.C.: Island.Google Scholar
- Lee, T.N., E. Johns, N. Melo, R. Smith, P. Ortner, and D. Smith. 2006. On Florida Bay hypersalinity and water exchange. Bulletin of Marine Science 79: 301–327.Google Scholar
- Light, S.S., and J.W. Dineen. 1994. Water control in the Everglades: A historical perspective. In Everglades: The ecosystem and its restoration, ed. S.M. Davis and J.C. Ogden, 47–84. Delray Beach: St. Lucie.Google Scholar
- Nance, J.M. 1994. A biological review of the Tortugas pink shrimp fishery through December 1993. Galveston: Galveston Laboratory, Southeast Fisheries Science Center, National Marine Fisheries Service.Google Scholar
- RECOVER. 2007. Final draft 2006 system status report, pilot assessment reports for the monitoring and assessment plan modules. Jacksonville: Restoration Coordination and Verification Team, U.S. Army Corps of Engineers, Jacksonville District.Google Scholar
- RECOVER. 2008. Southern coastal systems salinity performance measure. Restoration Coordination and Verification Team, U.S. Army Corps of Engineers, Jacksonville District, Jacksonville. http://www.evergladesplan.org/pm/recover/recover_docs/perf_measures/090108_se_salinity.pdf. Accessed 10/30/09.
- Schmidt, T.W. 1979. Ecological study of fishes and water quality in Florida Bay, Everglades National Park, Florida. RSP-EVER N-36. Homestead: South Florida Research Center, Everglades National Park.Google Scholar
- Smith, T.J., H.H. Hudson, M.B. Robblee, G.V.N. Powell, and P.J. Isdale. 1989. Freshwater flow from the Everglades to Florida Bay: A historical reconstruction based on fluorescent banding in the coral Solenatrea Bournoni. Bulletin of Marine Science 44: 274–282.Google Scholar
- Swart, P.K., G.F. Healy, R.E. Dodge, P. Kramer, J.H. Hudson, R.B. Halley, and M.B. Robblee. 1996. The stable oxygen and carbon isotopic record from a coral growing in Florida Bay: A 160 year record of climatic and anthropogenic influence. Paleogeography, Paleoclimatology, Paleoecology 123: 219–237.CrossRefGoogle Scholar
- Tabachnick, B.G., and L.S. Fidell. 2007. Using multivariate statistics, 5th ed. Boston: Allyn and Bacon.Google Scholar
- US Army Corps of Engineers and South Florida Water Management District. 1999. Central and Southern Florida project comprehensive review study, final integrated feasibility report and programmatic environmental impact statement. Jacksonville: United States Army Corps of Engineers, Jacksonville District.Google Scholar
- US Army Corps of Engineers and South Florida Water Management District. 2002. Florida Bay/Florida Keys feasibility study. United States Army Corps of Engineers, Jacksonville District, Jacksonville. http://www.evergladesplan.org/pm/studies/fl_bay.aspx#details. Accessed 11/9/09.
- Zieman, J.C. 1982. The ecology of the seagrasses of south Florida: A community profile. FWS/OBS-82/25. Washington, D.C.: U.S. Fish and Wildlife Service.Google Scholar
- Zieman, J.C., J.W. Fourqurean, and R.L. Iverson. 1989. Distribution, abundance, and productivity of seagrasses and macroalgae in Florida Bay. Bulletin of Marine Science 44: 292–311.Google Scholar