Zoobenthos of the Cheshskaya Bay (southeastern Barents Sea) : spatial distribution and community structure in relation to environmental factors

Structural and functional characteristics of zoobenthos of the Cheshskaya Bay (SE Barents Sea) were studied at 21 stations in June/July 1995. Strong prevailing cyclonic and tidal currents result in relatively uniform temperature and salinity in the area. Sediments consist mainly of sand and pebbles, while the flux of suspended matter from rivers locally increases the share of finer fractions. Analysis of species composition (419 taxa), abundance (up to 4,200 ind m−2 and up to 29,000 ind m−2 with juveniles) and biomass (up to >6,000 g wet wt m−2) indicates high species richness in most parts of the bay, especially in the northeast. Analysis of community structure using production characteristics of species revealed a general predominance of suspension feeders partitioned into seven communities. The dominant species of these communities were Mytilus edulis and Balanus crenatus (Type 1), B. crenatus (Type 2), Modiolus modiolus and Verruca stroemia (Type 3), Flustra foliacea and V. stroemia (Type 4), Hydrallmania falcata (Type 5), V. stroemia and Chirona hameri (Type 6), and Ophelia limacina (Type 7). The structure of the communities is mainly regulated by sediment type, water depth and, to some extent, by riverine input.