Bioaccumulation of Chemical Elements and Organic Carbon in the Macrozoobenthic Organisms of the Laptev Sea

Abstract

Within the framework of the program “Marine Ecosystems of the Siberian Arctic”, based on the materials collected during the 69th and 72nd cruises of the R/V “Akademik Mstislav Keldysh”, a study of the distribution of a group of chemical elements (As, Ba, Bi, Co, Cr, Cr, Cd, Co, Cu, Cr, Mn, Ni, Pb, Sc, Ti, Tl, Th, V, U and Zn) and organic carbon in the mass taxa of the Laptev Sea macrozoobenthos in the fields of methane seepage and outside them was carried out. For the first time, the bioaccumulation potential (BP) was quantified, taking into account, along with the concentration of elements in organisms, their biomass. At the C-15 methane field, the population of brittle stars accumulates each of the microelements many times (up to 40 times) more than at the background station. Brittle stars and bivalves show increased BP for Ni, As, Ba, Cu, Ti, V, Mn, and Zn compared to other elements, with brittle stars having significantly higher BP. It is assumed that the increased bioaccumulation of some heavy metals and metalloids in methane seep areas is associated with a greater bioavailability of organic matter in bottom sediments. For organic carbon, the highest BP was established, which is especially expressed in the C-15 methane field. At the background station, taxa accumulate a significantly smaller (by a factor of 10) amount of carbon in their biomass. As a result of the functioning of the ground eaters, bottom sediments are enriched with organic carbon, which may indicate an important contribution of benthic organisms to the carbon cycle in the seas of the Arctic.