TOTAL EPIPHYTE AND EPIPHYTIC CARBONATE PRODUCTION ON THALASSIA-TESTUDINUM ACROSS FLORIDA BAY

Previous investigations of epiphytic carbonate production have suggest ed that seagrass epiphytes are significant producers of calcium carbon ate and may be a primary source of lime muds in Florida Bay. This stud y determined total epiphyte and epiphytic carbonate standing stocks an d calculated minimum estimates of yearly production at seven sites wit hin Florida Bay and one site oceanside of the northern Florida Keys. T hese sites span a larger geographical area of increased environmental variability than those of previous Florida Bay epiphyte studies which were conducted in areas where conditions are considered favorable for epiphyte production. Total epiphyte and epiphytic carbonate loads alon g with seagrass shoot density and productivity were measured during fo ur periods between August 1991 and August 1992. Epiphyte composition, standing stock, and production all exhibited marked variation across F lorida Bay. Calcifying epiphytes were dominant in Florida Bay, and the ir distribution and the distribution of epiphyte production appear to reflect differences in the physical characteristics of salinity and th e variability thereof. Minimum estimates of annual epiphytic carbonate production range from 1.9 g CaCO3.m-2.yr-1 to 282.7 g CaCO3.m-2.yr-1, a range lower than previous estimates. The differences between these estimates and previous ones are attributed to differences in environme nts and, to a lesser extent, differences in methodology.