TEMPORAL AND SPATIAL VARIABILITY IN BENTHIC FORAMINIFERA FOSSIL ASSEMBLAGES OFF THE CONTINENTAL SHELF, CHARLESTON, SC

As part of the College of Charleston's Transect Program, four research cruises were conducted over a two-year period, sampling across the South Carolina continental shelf adjacent to Charleston. Sediment grab sample collections were conducted on each cruise at the same eight cross-shelf stations, in waters with depths ranging from 10 to 100 m. Between 25 and 39 benthic foraminifera genera (>125 micron size fraction) were identified for a single cruise, with more than 10 “dominant” genera (> 5 % of the genera at any station), including Quinqueloculina, Textularia, Hanzawaia, Cibicides, Triloculina, Bigenerina, Bolivina, Eponoides, Amphistegina, and Elphidium. The distribution of foraminifera along the Charleston Transect only partially compliments previously documented patterns along the southeast shelf and the Gulf of Mexico. For each cruise collection, considerable cross-shelf assemblage and dominant genera variability existed. Although similar foraminifera were identified from samples collected on each cruise, the spatial distribution of dominant genera showed a high degree of temporal variability for the four cruise collections. Sediments in the study region consist of a thin veneer of modern and relict sands, underlain by limestone hardground. Video of the seafloor collected with a remotely operated vehicle shows evidence of migrating sand megaripples which may be responsible for the seasonal reworking and redistribution of sediments. Sediment characteristics within the megaripples vary with respect to grain size and composition, and may be influencing the foraminiferal assemblage composition. Comparisons will be presented on foraminiferal assemblage variations and distribution with respect to grain size analyses and video data collected with a remotely operated vehicle.