Blakesley, B. A.. Florida Marine Research Institute, Fl. Department of Environmental Protection, Blakesley_B@Epic7.dep.state.fl.us
Hall, M. A.. Florida Marine Research Institute, Fl. Department of Environmental Protection, Hall_P@Epic7.dep.state.fl.us
White, M. W.. Florida Marine Research Institute, Fl. Department of Environmental Protection, White_W@Epic7.dep.state.fl.us
SPATIAL PATTERNS OF THALASSIA DECLINE AND INCIDENCE OF LABYRINTHULA INFECTION IN FLORIDA BAY, USA
Patterns of decline of the seagrass Thalassia testudinum and incidence of the pathogenic slime mold Labyrinthula sp from spring 1995 to spring 1998 are compared in 10 basins in Florida Bay. Methods of analysis using ArcView GIS with the extension Spatial Analyst are discussed. Changes in Thalassia distribution and abundance are compared with Labyrinthula incidence between and across seasons using the Inverse Distance Weighted method. Seven seasons of biannual sampling results are mapped for Thalassia Braun-Blanquet abundances, prevalence of Labyrinthula, salinity, and water temperature. A comparison of other individual biotic and abiotic factors with Thalassia distribution and abundance and Labyrinthula infection may clarify the reasons for the continuing seagrass decline.
Results confirm previous findings that salinity plays a critical role in controlling Labyrinthula infections in the bay. The highest levels of both Thalassia decline and Labyrinthula incidence are found in the western basins of Florida Bay where the initial Thalassia die-offs began in the late 1980's. These changes over the course of the study in the west are compared to those in central and eastern basins. In addition to the overall trends noted, there were also short-term spikes in infection in individual basins for which hypothesized contributing factors are presented.
Day: Wednesday, Feb. 3
Location: Sweeney Center