Bioaccumulation of Trace Elements in the Organisms of Benthic Communities in the Reducing Environments of the Sea of Okhotsk

A comparative study of the bioaccumulation of trace elements in benthic organisms inhabiting the area of methane seeps in the Deryugin Basin and nearby the Paramushir Island (Sea of Okhotsk) has been performed. The data pertain to both essential elements (Fe, Mn, Ni, Co, Cr, and Cu), which are necessary in certain concentrations for the metabolism of organisms, and nonessential heavy metals (Cd, Pb, and Hg), as well as As, a toxic metalloid. Dominating representatives of the bottom fauna from the Deryugin Basin (sea anemones, clams) were characterized by high bioaccumulation coefficients of most of the elements (≥ n103), regardless of their biochemical properties. The use of the coefficient K, which characterizes the accumulation of trace elements in the soft tissues of bivalves relative to their shells, allowed us to detect differences in the bioaccumulation character. Symbiotrophic bivalves of the family Vesicomyidae from the Deryugin Basin were characterized by the accumulation of all of the trace elements mostly in soft tissues (gills, primarily) compared to the carbonate shells (coefficient K > 1). We suppose that different effect of abiotic (biological availability of elements and water turbidity) and biotic (throphic strategy) factors of the habitats may probably be a reason of such phenomenon.