A Comparison of Belt Quadrat and Species Presence/Absence Sampling of Stony Coral (Scleractinia and Milleporina) and Sponges For Evaluating Species Patterning on Patch Reefs of the Central Bahamas

Two methods of evaluating patterning in stony coral and sponge communities were utilized on selected patch reefs in the Exuma Cays Land and Sea Park (24°22′N, 77°30′W) in the central Bahamas. Reefs were chosen for low algal coverage and the dominance of sponges and corals in terms of area coverage, and were grouped into 1.) channel patch reefs and 2.) soft coral-sponge patch reefs. Shallow patch reefs (<4 m depth) were selected from low-altitude, natural-color aerial photographs based on size, color, and location. Field survey techniques were employed to evaluate the viability of photo-interpretation of reef types. Two survey techniques used to evaluate the patch reefs were a.) species presence and absence lists and b.) belt quadrats. Data collected from these survey methods were used to calculate sponge and coral colony densities, species area coverage, and species diversity. The belt quadrat technique can account for the density of dominant benthic sessile invertebrates as well as species area coverage, and thus is a better method for characterizing patch reef communities. This field method allowed for the quantitative grouping of patch reef communities based on observed natural color characteristics.