ORGANOCHLORINE PESTICIDES AND PCBS IN THE EAST ICE HARP SEAL (PHOCA-GROENLANDICA) POPULATION

Blubber samples from the Eastern harp seal (Phoca groenlandica) popula tion were obtained during the moulting season in the Russian sector ou tside of the White Sea, in April and May 1993. Subcutaneous blubber of adult males and females, and juveniles of both sexes was sampled. The following organochlorines were determined: the industrial chemicals P CBs (polychlorinated biphenyls; 21 individual PCB congeners) and HCB ( hexachlorobenzene); and the organochlorine pesticides DDT (dichlorodip henyltrichloroethane), Sigma HCH (sum of hexachlorocyclohexane isomers ; alpha-, beta- and gamma-HCH); and Sigma CHL (sum of chlordane metabo lites; oxychlordane, cis-chlordane and trans-nonachlor). A total of 16 PCB congeners, the p,p'-DDT metabolites, and all the pesticides, exce pt gamma-HCH, were detected in all animals. The concentrations of Sigm a PCB (sum of concentrations of 21 PCB congeners) and Sigma DDT (sum o f concentrations of p,p'-DDT, p,p-DDE, p,p'-DDD, o,p'-DDT and o,p'-DDD ) ranged from 0.8-9.8 and 0.6-7.9 mu g g(-1) lipid weight, respectivel y. The median concentrations of HCB, the chlordane metabolites oxychlo rdane, cis-chlordane and trans-nonachlor, and the HCH isomers were all < 1 mu g g(-1) lipid weight. When comparing two adult male groups cau ght early, and late in the moulting period, significantly higher HCB l evels were found in the latter and leanest group. Although not statist ically significant, the same trend was observed in the case of Sigma P CB, Sigma DDT, Sigma CHL and Sigma HCH. There is probably a differenti ated relative release of organochlorines from the blubber reservoir du ring the moult in adult males. Significantly higher concentrations of the three major pollutants (Sigma PCB, Sigma DDT and Sigma CHL) were f ound in adults as compared to the juveniles, while no such relations w ere found for Sigma HCH or Sigma HCB. Although the concentrations of S igma PCB, Sigma DDT, Sigma CHL and Sigma HCH in blubber of different h arp seal groups were not significantly different with respect to sex, a multiple regression analysis including LMD-index, sex and age indica ted that there were fewer concentrations of PCB, DDT, CHL and Sigma HC H in adult female seals compared to males and juveniles. Copyright (C) 1996 Elsevier Science Ltd