Macrofaunal abundance at 79 degrees N off East Greenland: opposing data from epibenthic-sledge and box-corer samples

During the expedition ARK XI-2 with RV Polarstern in September/October 1995 , a transect of samples was taken off East Greenland from the shelf down to about 1800 m depth by means of an epibenthic sledge and a giant box corer, in order to obtain information on epibenthic and endobenthic macrofauna. W ithin the epibenthic sledge catches, the Cumacea were the most numerous tax on with 32,123 (always calculated for 1000 m) specimens, followed by the Is opoda with 26,914 specimens, and Amphipoda with 20,900; Mysidacea and Tanai dacea were less important. Amphipoda were the most numerous taxon on the sh elf, while with increasing depth Isopoda and especially Cumacea became incr easingly important. Macrofauna;analysed from the box-corer samples decrease d in abundance with depth. The highest macrofaunal abundance was found on t he shelf, with 8128 ind. m(-2) (200 m); below this depth, density decreased from approximate to 2000 ind. m(-2) (at 800 m) to approximate to 800 ind. m(-2) (2000 m). Peracarid crustaceans and polychaetes were, next to bivalve s, the most frequent. Polychaetes clearly dominated the shelf communities; their relative percentage decreased with increasing water depth while the r elative percentage of Peracarida increased simultaneously. Interestingly, t he highest number of peracarids in the epibenthic-sledge samples was report ed from deep sea, while box-corer samples showed decreasing macrofaunal abu ndance with depth. The relative percentage of peracarids in the box-corer s amples increased with depth, while in;absolute numbers, peracarids from the se samples were also highest on the shelf at about 200 m depth.