Persistent toxic substances in the muscles and liver of the pacific walrus Odobenus rosmarus divergens Illiger, 1815 from the Bering Sea

This study reports data on the contents of organochlorine pesticides and heavy metals in the muscles and livers of eight individuals (five males and three females) of the Pacific walrus Odobenus rosmarus divergens Illiger, 1815, which were captured in the summer of 2011 in Mechigmensky Bay of the Bering Sea. Pesticides, namely alpha-, beta-, and gamma-isomers of hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its metabolites dichlorodiphenyldichloroethane (DDD) and dichlorodiphenyldichloroethylene (DDE), as well as the heavy metals Cd, Pb, and Hg were found in all samples studied. The total concentration of organochlorine pesticides in the muscles varied from 200 to 5700 ng/g lipid weight and in the liver from 4900 to 90300 ng/g lipid weight. The concentrations of cadmium, lead, and mercury were 0.04-6.7, 0.13-0.76, and 0.03-0.40 mu g/g dry weight, respectively. On the whole, the contents of organochlorine pesticides and heavy metals in the organs of the Pacific walrus were lower compared to those in marine mammals from other regions of the World Ocean.