The species composition of the Peracarid fauna (Crustacea, Malacostraca) of the Northeast Water Polynya (Greenland)

Abstract

The species composition of Crustacea, Peracarida was investigated over a period of almost three months in the Northeast Water Polynya (NEW) off Greenland. Samples were collected in May - July 1993 during the Polarstern expedition ARK IX/2-3 using an epibenthic sledge. Within the macrobenthos on the shelf, peracarids were an important component, besides polychaetes, molluscs and brittle stars. At 22 stations in depths from 45-517 m, about 38 000 specimens were identified and have been listed.

In total, 229 species belonging to 51 families, and 121 genera were found. Seven species assemblages were characterized: the "deep assemblage", the "shallow assemblage", the "Westwind Trough assemblage", the "Norske Trough assemblage", the "common species assemblage", the "high-accumulation area assemblage", and the "ice-associate assemblage". Differences in abundance and composition do not primarily reflect bathymetric gradients, but more the availability of food (phytoplankton, more importantly ice algae incorporation into the sediment) and therefore the temporal and spatial opening of the polynya. It is suggested that primary production, hydrography, and ice conditions (lateral advection due to the  anticyclonic gyre around Belgica Bank, and upwelling at a southern fast-ice extension) are the main factors influencing the peracarid crustacean community.