Persistent organic pollutants in Alaskan murre (Uria spp.) eggs: Geographical, species, and temporal comparisons

Concentrations of persistent organic pollutants (POPs) in eggs of common and thick-billed murres (Uria aalge and U. lomvia) from five Alaskan nesting colonies were dominated by 4,4‘-DDE, total polychlorinated biphenyls (ΣPCBs; 46 congeners comprised mainly of PCB congeners 153, 118, 138, 99, and 151), hexachlorobenzene (HCB), β-hexachlorocyclohexane (β-HCH), and chlordane compounds (ΣCHL). Concentrations of 4,4‘-DDE, cis-nonachlor, and heptachlor epoxide were lower than those reported for some of the same colonies in the 1970s, while HCB concentrations were similar. In general, significantly higher concentrations were found in eggs from Gulf of Alaska colonies compared to those from Bering Sea colonies except for HCB (higher in the Bering Sea) and β-HCH (no significant difference between the two regions). Thick-billed murre eggs contained higher concentrations of 4,4‘-DDE and ΣPCBs, whereas common murre eggs had higher HCB concentra tions. Possible factors contributing to the POPs patterns found in eggs from these murre colonies are discussed.