PCBs in Arctic seabirds from the Svalbard region

Previous studies have indicated the presence of high levels of organochlorines, especially PCBs, in some species of arctic seabirds. The glaucous gull (Larus hyperboreus) in particular has shown high levels of organochlorine contamination. We present data on total PCB and isomer specific PCBs in liver samples from four species of seabirds from the Svalbard region. Two of the species were sampled both in the vicinity of the mining town Longyearbyen, where PCBs have been used in the past, and in the remote region of Nordaustlandet. We compared the levels obtained from these two localities in order to test for any indication of local contamination in the Longyearbyen area. No significant difference was found in total hepatic PCB between glaucous gulls collected at Longyearbyen and those collected at Nordaustlandet (grand mean ± S.D.: 15.59 ± 21.53 μg/g wet wt.; n = 22). Similarly, no difference was found in black guillemots (Cepphus grylle) from these two regions (grand mean ± S.D.: 0.14 ± 0.05 μg/g wet wt.; n = 20). However, in both species, we found significantly higher levels of higher chlorinated biphenyls in the Longyearbyen samples, and higher levels of lower chlorinated biphenyls in the samples from Nordaustlandet. This finding indicates that the birds sampled at the two localities might have been contaminated by different sources. Local contamination in the Longyearbyen area is one of several possible explanations for this difference. Total PCB levels in common eiders (Somateria mollissima) and Bru¨nnichʹs guillemots (Uria lomvia) were in the same order of magnitude as those for the black guillemots (mean ± S.D.: 0.04 ± 0.04 μg/g; n = 11 and 0.08 ± 0.04 μg/g; n = 8, respectively).