Temporal variation in circulating concentrations of organochlorine pollutants in a pelagic seabird breeding in the high arctic

The present study explored short-term temporal variations in circulating concentrations of three legacy organochlorines (OCs) with different physicochemical properties (polychlorinated biphenyl 153 [PCB-153], p,p'-dichlorodiphenyldichloroethylene [DDE], and hexachlorobenzene [HCB]) in breeding kittiwakes (Rissa tridactyla) in a colony in Svalbard (78oN), Norwegian Arctic. Concentrations were measured in blood of a large number (n = 412-521 blood samples, depending on the data-analyses), of pre-breeding, incubating and chick-rearing birds over a period of five years (2007-2011). PCB-153 concentrations were equal in male and female blood in the pre-breeding period, whereas females had significantly lower concentrations during incubation and chick rearing, probably due to their ability to eliminate OCs through egg laying. A similar temporal pattern was observed with DDE although the lower concentrations in incubating females were not significant. Males and females had similar concentrations of HCB over all reproductive stages. The concentrations of all three compounds varied greatly between years. PCB-153 tended to decline over the study period while HCB showed an increasing trend, especially among chick-rearing males late in the season. Concentrations of PCB-153 increased about 2.5 times from the pre-breeding to the chick-rearing period, concurrent with mobilization of body lipids (reduced body mass). A similar, but less pronounced trend was found for HCB. For DDE, however, kittiwakes had the highest concentrations in the pre-breeding period, suggesting relatively high exposure in their winter areas. The present study documented large variations in circulating concentrations of legacy OCs among and within breeding seasons in kittiwakes, but the alterations within seasons were relatively consistent from year to year. This article is protected by copyright. All rights reserved