Long-term benthic population changes (1920-1930s-present) in the Barents and Kara Seas

Bottom sediment was analysed, via grab, trawl and underwater photography in 1991-1992 in the Barents, White, Kara, Norwegian and Greenland Seas, and the large scale features of macrobenthos distribution aredescribed. The maps of alpha-diversity, biomass and trophic zone distribution on the investigated shelf are presented. Statistical assessment of the bottom community structure changes during the last 60-70 years for the Barents Sea area is presented. It is shown that on regional and transregional levels the researched communities are of natural undisturbed character and that the revealed changes may be both the result of natural processes or sampling errors. Local disturbances of benthos composition and structure, supposedly caused by man, are found to be rare not far from the Novaya Zemlya and Murman coasts. [ABSTRACT FROM AUTHOR]