Environmental influences on benthic fauna associations of the Kara Sea (Arctic Russia)

Macrobenthic faunal associations, hydrography and sediment structure were e xamined at 14 stations in the Kara Sea. The stations were located in an are a influenced by huge runoff from the Ob and Yenisei Rivers and in areas inf luenced by Barents Sea water, Sampling depths varied from 17 to 43 m, with one station at 195 m. The sediments were predominantly muddy but some stati ons were sandy. Three hundred and eighty-seven taxa were identified and Pol ychaeta, Crustacea and Mollusca were the most conspicuous. Species number, abundance and biomass varied widely among stations, and were generally high er in the more marine waters. Boreal-arctic species predominated, but an in crease of arctic species from marine to the estuarine areas was evident. Fi ve faunal associations were delineated by cluster analysis and suggested qu ite heterogeneous sampling areas. The most conspicuous species of each faun al association were Spiochaetopterus typicus? Tridonta borealis, Serripes g roenlandicus, Portlandia arctica, and Marenzelleria arctia, respectively. T he sedimentation rate, as well as depth, sediment structure and salinity, a pparently influenced the main differences in the fauna.