Winter studies of under-ice benthos on the continental shelf of the northeastern Bering Sea

Abstract

A total of 76 samples from 16 benthic stations over the eastern Bering Sea shelf were taken between 31 January and 17 February, 1970 for purposes of assessing the quantity and distribution of benthic macrofauna. A total of 129 species or taxa were found, with an average density of 1,133 indiv/m^2 and average biomass of 127 g wet/m^2. Species were subjected to elemental analysis for determination of organic carbon and nitrogen content, yielding average values of 5.1% carbon and 1.1% nitrogen expressed as percentage wet weight, which translated into biomass values of 6.5 g C/m^2 and 1.4 g N/m^2 averaged over all stations. Correlation studies yielded 9 species affinity groups, and regression analysis indicated that about 40% of the variability of distribution and density of the major species could be accounted for by salinity, sediment mode particle size, depth, temperature, or dissolved oxygen, with no one factor assuming dominance. Of the 129 species or taxa, 35 account for about 80% of total numbers, wet weight biomass, or carbon biomass, with 8 species making up over 50% of the totals in all categories. Of these 35 major species, 8 are known to be food species of the Pacific walrus. These 8 comprise only 10% of the total number of individual organisms encountered, but make up 60% of the wet weight biomass and 49% of the carbon biomass over the region, sampled.