Concentrations and patterns of organochlorine contaminants in white whales ( Delphinapterus leucas) from Svalbard, Norway

Abstract

Blubber was collected from live-captured, adult male white whales ( Delphinapterus leucas) from Svalbard, Norway, and analysed for levels and patterns of organochlorine (OC) contaminants. The OC compounds analysed were HCB, dieldrin, ΣHCH (α-HCH, β-HCH and γ-HCH), ΣChl (heptachlor epoxide, oxychlordane, cis-chlordane, trans-nonachlor, and cis-nonachlor), ΣDDT ( pp′-DDT, pp′-DDE and pp′-DDD) and ΣPCB (27 PCB congeners). The major OC compounds detected in the blubber were ΣPCB (5103±1874 ng/g l.w.) and ΣDDT (5108±1089 ng/g l.w.), which made up 70% of the ΣOC. These compounds were followed in prevalence by ΣChl (2872±1177 ng/g l.w.), which contributed 20% of the ΣOC burden. ΣHCH, HCB and dieldrin were present, but at low concentrations. This OC pattern is typical of top predators in Arctic marine food chains. OC levels in white whales from Svalbard are lower than white whales from the St Lawrence River in Canada and are generally similar to values reported previously for other Arctic white whale stocks. Some geographic patterns in relative prevalence of various OC compounds appear to be quite consistent among various marine mammal species in the Arctic. PCB and DDT concentrations in Svalbard's white whales are below the levels that are thought to have negative effects on reproduction or the immune system.