Abundance, diversity and community patterns of epibenthic- and benthic-boundary layer peracarid crustaceans at 75 degrees N off East Greenland

During an expedition of RV Polarstern in 1994, a vertical transect (about 200-, 300-, 450-, 800-, 1,500- and 2,200-m depth) and a horizontal transect (of three stations at about 800-m depth) were sampled at 75 degrees N off Greenland with an epibenthic sledge in order to obtain information on the abundance, diversity and community patterns of epi- and suprabenthic peracarid crustaceans, which are known to be an important component of the macrofauna along the Greenland continental shelf and slope. We wanted to scrutinize whether a hypothesized enhanced primary production along the ice edges would reflect upon benthic biomass. Within the peracarid community a total of 14,784 individuals were collected at these locations, while an additional 2,425 specimens were sampled at a 500-m station at 79 degrees N, in an area where samples had been also taken in 1993. For reasons of comparison, numbers of peracarids found at any one station were calculated for 1,000-m trawled distance. These calculations accounted for 55,633 specimens on both transects. Of these, the order Isopoda was the most numerous taxon with 28,650 specimens, followed by the Amphipoda with 15,025 specimens, Cumacea with 7,868, Tanaidacea with 2,454 and the suprabenthic Mysidacea with 1,636 individuals collected at all stations during this expedition, respectively. Interestingly the highest number of individuals was sampled at 1,525-depth (23,098 individuals); however, at about 2,680-m depth the number of peracarids collected (13,557) was still much higher than at comparatively shallower stations, for example, in 317-m depth (6,792). Possible reasons for these findings are discussed.