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South Florida Fisheries Habitat Assessment Program (FHAP-SF)

Seagrass bed underwater

In 1995, FWRI researchers Drs. Margaret Hall and Michael Durako started the Fisheries Habitat Assessment Program (FHAP) to track the status and recovery of essential fish habitat (i.e., seagrasses and macroalgae) in Florida Bay following the unprecedented mass mortality (or “die-off”) of Thalassia testudinum (turtle grass) that took place there from 1987-1991.  FHAP is now a component of the Monitoring and Assessment Plan of RECOVER (Restoration, Coordination and Verification) within the Comprehensive Everglades Restoration Plan (CERP), and with continued support and funding from the South Florida Water Management District, FHAP has become one of the longest running benthic monitoring programs anywhere in Florida. 

A boat with two people is anchored in the ocean.

Today, FHAP documents seagrass and macroalgal communities in 19 basins distributed throughout Florida Bay and the Lower Everglades.  To do this, FWRI seagrass scientists, in collaboration with University of North Carolina Wilmington (UNCW), visit 29-31 random locations in each basin every year, at the end of the dry season (May–June) when heat and hypersalinity begin to threaten the ecosystem.  Twice a year, we sample 15 permanent transects, once at the end of the dry season (May-June) and again after the wet season (October–November).  This allows us to capture important seasonal variability in seagrass shoot density and biomass.  In all, we visit more than 500 locations and gather thousands of detailed observations regarding the environmental and ecological conditions. To help us, we use a modified version of Braun-Blanquet scale, which scores seagrass and macroalgae based off the number of individuals and how much of a 0.25-m2 square they cover.   

An underwater diver is floating over a seagrass bed and writing on a clipboard. There is a square shaped white PVC pipe covering a section of the seagrass bed.

We also collect turtle grass shoots for leaf morphometrics (the quantitative analysis of form and shape), and for epiphyte biomass. Along the 50-m transects we collect Braun-Blanquet data, count seagrass shoots, and harvest seagrass above and belowground biomass using PVC cores. Samples are brought back to the lab for processing.  At every site, we record water, sediment and Secchi depths, and measure light quality, water temperature, pH, salinity, and dissolved oxygen.  

Long-term monitoring programs like FHAP provide ecological and historical context with which to understand ecosystem responses to meteorological, climatic, and human-related disturbances, as well as planned management action, such as those possible under the Comprehensive Everglades Restoration Plan (CERP).  Florida Bay has undergone significant changes in the last 100 years and will no doubt continue to be a dynamic place as resource managers attempt to restore more natural water flows to South Florida, and as the region responds to climate change and sea level rise.  FHAP data and analysis offer a consistent and objective contribution to management discussion and public discourse regarding the status and trends of seagrasses within this iconic estuary.

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Florida Bay Literature

Carlson DF, Yarbro LA, Scolaro S, Poniatowski M, McGee-Absten V, Carlson PR (2018) Sea surface temperatures and seagrass mortality in Florida Bay: Spatial and temporal patterns discerned from MODIS and AVHRR data. Remote Sensing of Environment, 208:171-188.

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Hallac DE, Sadle J, Pearlstine L, Herling F, Shinde D (2012) Boating impacts to seagrass in Florida Bay, Everglades National Park, Florida, USA: links with physical and visitor-use factors and implications for management. Marine and Freshwater Research, 63(11): 1117-1128. 

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Madden CJ, Rudnick DT, McDonald AA, Cunniff KM, Fourqurean JW (2009) Ecological indicators for assessing and communicating seagrass status and trends in Florida Bay. Ecological Indicators, 9:S68-S82. 

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Peterson BJ, Frankovich TA, Zieman JC (2007) Response of seagrass epiphyte loading to field manipulations of fertilization, gastropod grazing and leaf turnover rates. Journal of Experimental Marine Biology and Ecology, 349(1): 61-72. 

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Armitage AR, Frankovich TA, Heck Jr. KL, Fourqurean JW (2005) Experimental nutrient enrichment causes complex changes in seagrass, microalgae, and macroalgae community structure in Florida Bay. Estuaries, 28(3):422-434.

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MO Hall (1999) Decadal changes in seagrass distribution and abundance in Florida Bay. Estuaries, 22(2B): 445-459.

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Fourqurean JW, Robblee MB (1999) Florida Bay: A history of recent ecological chances. Estuaries, 22: 345-357.

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Rose CD, Sharp WC, Kenworthy WJ, Hunt JH, Lyons WG, Prager EJ, Valentine JF, Hall MO, Whitfield PE, Fourqurean JW (1999) Overgrazing of a large seagrass bed by the sea urchin Lytechinus variegatus in outer Florida Bay. Marine Ecology Progress Series, 190:211-222. Doi:10.3354/meps190211 

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Corbett DR, Chanton J, Burnett DW, Rutkowski K, Fourqurean C, Fourqurean JW (1999) Patterns of groundwater discharge into Florida Bay. Limnology and Oceanography, 44:1045-1055

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Carlson Jr. PR, Yarbro LA, Barber TR (1994) Relationship of sediment sulfide to mortality of Thalassia testudinum in Florida Bay. Bulletin of Marine Science, 54(3):733-746  

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Durako MJ (1994) Seagrass die-off in Florida Bay (USA): changes in shoot demographic characteristics and population dynamics in Thalassia testudinum. Marine Ecology Progress Series, 110:59-66. https://www.int-​res.com/abstrac​ts/meps/v110/ 

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Robblee MB, Barber TR, Carlson PR, Durako MJ, Fourqurean JW, Muehlstein LK, Porter D, Yarbro LA, Zieman RT, Zieman JC (1991) Mass mortality of the tropical seagrass Thalassia testudinum in Florida Bay (USA). Marine Ecology Progress Series, 77:297-299.   

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