Organochlorine contaminant and stable isotope profiles in Arctic fox ( Alopex lagopus) from the Alaskan and Canadian Arctic

PCBs in Arctic fox are lower than reported in other Arctic populations and unlikely to cause significant impairment of reproductive success. Arctic fox ( Alopex lagopus) is a circumpolar species distributed across northern Canada and Alaska. Arctic fox muscle and liver were collected at Barrow, AK, USA ( n=18), Holman, NT, Canada ( n=20), and Arviat, NU, Canada ( n=20) to elucidate the feeding ecology of this species and relate these findings to body residue patterns of organochlorine contaminants (OCs). Stable carbon (δ 13C) and nitrogen (δ 15N) isotope analyses of Arctic fox muscle indicated that trophic position (estimated by δ 15N) is positively correlated with increasing δ 13C values, suggesting that Arctic fox with a predominately marine-based foraging strategy occupy a higher trophic level than individuals mostly feeding from a terrestrial-based carbon source. At all sites, the rank order for OC groups in muscle was polychlorinated biphenyls (ΣPCB) > chlordane-related compounds (ΣCHLOR) > hexachlorocyclohexane (ΣHCH) > total toxaphene (TOX) ⩾chlorobenzenes (ΣClBz) > DDT-related isomers (ΣDDT). In liver, ΣCHLOR was the most abundant OC group, followed by ΣPCB > TOX > ΣHCH > ΣClBz > ΣDDT. The most abundant OC analytes detected from Arctic fox muscle and liver were oxychlordane, PCB-153, and PCB-180. The comparison of δ 15N with OC concentrations indicated that relative trophic position might not accurately predict OC bioaccumulation in Arctic fox. The bioaccumulation pattern of OCs in the Arctic fox is similar to the polar bear. While ΣPCB concentrations were highly variable, concentrations in the Arctic fox were generally below those associated with the toxicological endpoints for adverse effects on mammalian reproduction. Further research is required to properly elucidate the potential health impacts to this species from exposure to OCs.