Associations between persistent organic pollutants and vitamin status in Brünnichʹs guillemot and common eider hatchlings

The aim of the study was to examine associations between persistent organic pollutants and vitamin A (retinol), retinyl palmitate and vitamin E status (α-tocopherol) in two species occupying different trophic positions in the Arctic food web. Levels of polychlorinated biphenyls (PCBs), some selected organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) were analyzed in yolk sac of newly hatched chicks of Brünnichʹs guillemot (Uria lomvia) and common eider (Somateria mollissima) from Kongsfjorden, Svalbard (Norwegian Arctic) (79°N). Morphological variables were measured, and levels of retinol, retinyl palmitate and α-tocopherol were analyzed in plasma and liver. Brünnichʹs guillemot had significantly higher levels of POPs than common eider, as expected from its higher trophic position. Morphological traits seemed to be negatively related to POPs in Brünnichʹs guillemots, but not in common eiders. In Brünnichʹs guillemot, negative relationships were found between some OCPs (hexachlorobenzene, oxychlordane, p,p′-DDE) and liver α-tocopherol levels. The negative relationships between these OCPs and liver α-tocopherol levels in Brünnichʹs guillemot hatchlings became less evident when the confounding effect of liver mass was corrected for. In common eider positive relationships were found between summed PCB (ΣPCBs) and some OCPs (β-hexachlorocyclohexane, oxychlordane) and liver α-tocopherol levels. Differences in relationships between POPs and vitamin status in the two species may be related to differences in POP exposure levels linked to their trophic position in the Arctic marine food web, or to intrinsic physiological differences between the species