THE SPONGE ASSOCIATION OF THE ABYSSAL NORWEGIAN-GREENLAND-SEA - SPECIES COMPOSITION, SUBSTRATE RELATIONSHIPS AND DISTRIBUTION

During the 'Meteor' Expedition 13 in July and August 1990 to the north ern part of the Norwegian Sea off west Spitsbergen, 7 stations with a depth of 2000 m or more were sampled with Agassiz trawl or hyperbentho s sledge, 14 more with a large box corer. Sponges were found at 6 of t he trawl stations and in 2 box cores. A total of 19 species occurred, most of which were new to the area. Eight of the species were encounte red more often than the other 11. Literature review and check of unpub lished samples showed that by distribution, frequency of occurrence or abundance these species can be defined as the typical sponge associat ion of the Norwegian and Greenland abyssal sea. This sponge associatio n has a wide occurrence over the deep Norwegian-Greenland seas and par ts of the Arctic basins. The analysis of substrate utilization of the 8 core species shows that all of them are able to colonize soft bottom , even some that previously had been considered to be dependent on har d substrate exclusively. Alternative substrate utilization and, in som e species, the adoption of an infaunal life style are judged to be maj or reasons for the success of these species in the deep sea. The infau nal life style of the species Thenea abyssorum, Trichostemma sol and T entorium semisuberites is documented and population structure data are given for the first time.