Heavy metals in surface water of the Atlantic sector of the Antarctic during the 79th cruise of the research vessel “Akademik Mstislav Keldysh”

Abstract

Relevance of monitoring heavy metals content in the water of the Atlantic sector of the Antarctic is due to the need for a current assessment of quality of the marine environment for making responsible decisions on the conservation of marine living resources in this unique area of the World Ocean. The aim of the study was to obtain new data on levels and spatial distribution of concentrations of trace elements, mainly heavy metals, in surface water. Sampling of surface seawater was carried out during the Antarctic expedition of the 79th cruise of the RV “Akademik Mstislav Keldysh” at 21 stations in the area of the Drake Passage, the Bransfield Strait, and the Antarctic Sound, as well as in Weddell and Scotia seas. Extracting and concentrating of dissolved form of 13 trace elements (Be, Se, Sb, Tl, V, Pb, Cd, Cu, Zn, Ni, Mo, Co, and Fe) were performed using sodium diethyldithiocarbamate and carbon tetrachloride (CCl4). The elements were measured by mass spectrometry. Among all trace elements content, only Mo concentration in seawater at 9 stations, located in the Drake Passage, the Bransfield Strait, northern Weddell Sea, and off the southern coast of Tierra del Fuego Island, exceeded 1.2–2.8 times maximum permissible concentration of trace elements in fishery water bodies of the Russian Federation (MPCF). According to international regulatory legal acts, such as “Dutch sheets”, there were single cases of exceeding MPC (maximum permissible concentration under short-term exposure) for Cd and Zn, as well as exceeding TV (target value under chronic exposure) for Cu, Pb, Cd, Zn, Se, and Co at several stations. The research has shown as follows: despite limited anthropogenic pressure on this area of the Southern Ocean, in seawater of some regions of the Atlantic sector of the Antarctic, increased concentrations of several trace elements, inter alia heavy metals, are recorded. Further study of the sources of trace elements intake and the peculiarities of their distribution in seawater of the Atlantic sector of the Antarctic is required in order to account for ongoing processes, take measures for rational management, and provide ecologically acceptable use of natural resources in the Antarctic.