Chlorinated hydrocarbons in seabirds from the Barents Sea area

Abstract

This study presents preliminary results on the levels of organochlorines (OCs) in three seabird species: common eider (Somateria mollissima), kittiwake (Rissa tridactyla) and glaucous gull (Larus hyperboreus) from the Barents Sea area, including Frans Josef Land, Ny-A˚lesund, Bjørnøya and Hornøya, in July–August, 1991. Kittiwake was the only species collected at all four sampling areas, and all three species were sampled only at Ny-A˚lesund. Samples of liver, fat, muscle and brain tissue were analyzed for chlorinated pesticides, hexachlorobenzene (HCB), hexachlorocyclohexanes (α, β, γ-HCH), chlordanes (oxychlordane,trans-nonachlor and heptachlor epoxide), the DDT group (op′,pp′ DDT, DDD and DDE) and the industrial chemical polychlorinated biphenyls (PCBs). In all species, the highest OC levels were found in fat tissue, followed by liver, muscle and brain. PCBs were the major OC contaminants, followed by the DDT group, the chlordane group, HCB and the HCHs. Only low levels of HCHs were found. The lowest mean level of ΣPCB — sum of concentrations of the 19 individual congeners (2.8 μg/kg wet weight (w.w.)) — was found in the liver of juvenile common eider from Frans Josef Land. The highest mean level of ΣPCB (15 980 μg/kg w.w.) was found in the fat of adult glaucous gulls from Ny-A˚lesund. There were no significant geographical trends in OC contamination in the species investigated. However, the OC levels in kittiwake were highest at Bjørnøya. The OC contamination levels in seabirds from the Barents Sea region are in general lower in the 1990s than in past decades.