Spatial variation in hard bottom coral communities of the coastal West Florida Shelf

Abstract

Hard bottom coral and sponge communities differ along portions of the West Florida Shelf (WFS) in species occurrence, diversity, and/or size. However, the composition and spatial distribution of these communities are not well understood. Community transitions have been proposed in the central portion of the WFS around Tampa Bay, Cedar Key, and as far south as Charlotte Harbor, but supporting data are sparse. Fifteen sites in three regions of Florida were surveyed for species distribution, density, and demographics. Distinct communities were found between St Teresa, Hudson, and Tarpon Springs. Coral and sponge densities were highest off Tarpon Springs followed by St Teresa and lowest off Hudson. Stony corals (Siderastrea radians, Cladocora arbuscula, and Phyllangia americana) and octocoral complexes (Muricea spp. and Plexauridae) were the main drivers of differences between the regions. Several species of corals significantly varied in size between the three regions and stony corals in Tarpon Springs were significantly larger in 2021 than in the same region in 2017. Overall, the communities had healthy corals with no disease and minimal bleaching. This research broadens the understanding of WFS hard bottom communities and their spatial distributions through detailed surveys. Additional research on the hard bottom communities of the WFS is necessary to attain a comprehensive understanding of the coastal shelf and support long-term management.