Island in the Stream: Oceanography and Fisheries of the Charleston Bump

Benthic Habitats and Associated Fauna of the Upper- and Middle-Continental Slope Near the Charleston Bump

E. L. Wenner and C. A. Barans


Abstract.—The geological structure and characteristic community members of four relatively distinct benthic habitats, and their associated subhabitats, are described on the upper- and middle-continental slope just north of the Charleston Bump and below the deflection of the Gulf Stream eastward. The predominant habitats, identified from submersible surveys, included moderate-relief capped mounds, moderate-relief coral mounds, low-relief substrates and cohesive-mud substrates. Moderaterelief capped-mound habitats (185–220 m) due east of Charleston, South Carolina, were characterized by high local relief (about 20 m) outcroppings having abundant and diverse fish and sessile invertebrate communities. Moderate-relief coral-mound habitats, at depths of 503–555 m southeast of Charleston, consisted of mounds of dead coral fragments with a local relief of 15–23 m. Associated with the coral mounds was a depauperate assemblage of live coral and rare fish species. Yet, this habitat had a more diverse biological community than most of the low-relief subhabitats. Low–relief habitats at 293–567 m southeast of Charleston primarily consisted of fine sediments distributed in current generated patterns. Although epibenthic fish and invertebrate species were associated with this habitat, their abundance and diversity was relatively low. Cohesive-mud habitats at 150–250 m were distributed along depth contours for a long distance. Many of the species found here were associated with widely distributed tilefish Lopholatilus chamaeleonticeps burrows that impart negative relief to large areas of this flat habitat.