Blood concentration of organochlorine pollutants and wing feather asymmetry in Glaucous Gulls

1. Non-directional asymmetries (fluctuating asymmetry, FA) from bilateral symmetry in morphological traits have been used as an indicator of environmental stress and may become an important diagnostic tool in environmental sciences, such as ecotoxicology. 2. In this study the relationship was examined between wing feather asymmetry, measured as the difference between the length of the third primary on the left and right wing, and blood concentration of selected persistent organochlorines (OCs) in Arctic breeding Glaucous Gulls (Larus hyperboreus , Gunnerus). 3. There was a positive relationship between primary asymmetry and blood concentrations of two PCB (polychlorinated biphenyl) congeners (P < 0.05), oxychlordane (P < 0.05), DDE (p 'p '-dichlorodiphenyldichloroethylene) (P < 0.05), and especially HCB (hexachlorbenzene) (P < 0.001). At HCB levels above 30 ng g(-1) (wet mass) there was a 60% probability that the birds had asymmetric wing feathers. 4. This study indicated that the present levels of organochlorines in the European Arctic are stressors for Glaucous Gulls, and that asymmetry measurements of wing feathers may be used as an indicator of both exposure and effects of such contaminants. FA may also be a promising measurement for monitoring the early effects of organochlorine pollution on bird populations.