Macrofauna communities in surface sediments in the Amundsen Basin, at the Morris Jesup Rise and at the Yermak Plateau (Eurasian Arctic Ocean)

Macrofaunal communities of the western Eurasian Arctic Ocean were studied along a transect from the North Pole, across the Amundsen Basin and Gakkel Ridge towards the Morris Jesup Rise and the Yermak Plateau. Samples were collected during autumn 1991, from depths of 560±4411 m, using a box corer. Macrofaunal species numbers varied from 1 to 11 per 0.02 m2 in the basins approaching the Morris Jesup Rise and from 44 to 81 per 0.25 m2 at the Yermak Plateau. Abundances increased from 1 to 31 per 0.02 m2 in the basin and on the Morris Jesup Rise to 24±60 per 0.02 m2 on the Yermak Plateau. Biomass was low in the basin and at the Morris Jesup Rise (0.5±68.9 mg per 0.02 m2) but increased to 116.64 mg per 0.02 m2 at the Yermak Plateau. A total of 108 taxa were recorded. The results contradict the hypothesis that diversity decreases with increasing latitude, and the high species richness at low abundance at intermediate depths was comparable with that observed in Antarctic and tropical regions.