Bottom Communities of Sedova Bay (Novaya Zemlya, the Kara Sea)

Abstract—The benthic fauna of Sedova Bay (Kara Sea, Novaya Zemlya Archipelago) was studied during two cruises of the R/V Academik Mstislav Keldysh in 2015–2016. Three macrobenthic communities were described. The species composition of the benthic communities is formed by two orthogonal environmental gradients: vertical (depth) and horizontal (the distance from the apex of the bay). Horizontal changes are mainly determined by terrigenous runoff, despite the generally low content of suspended particles in the water column of the bay. This factor determines the trophic conditions for benthic invertebrates and affects the changes in the share of dominant species within one assemblage. An increased effect of this factor results in significant reorganization of bottom communities (disappearance of a number of species, separation of the marginal communities, and fauna depletion) as were described for the neighboring bays on the eastern coast of Novaya Zemlya.