Trace elements in king eiders and common eiders in the Canadian Arctic

We determined concentrations of selected trace elements in tissues of king and common eiders at three locations in the Canadian arctic. Renal and hepa tic cadmium concentrations in king eiders at a location in the eastern arct ic were among the highest ever recorded in eider ducks: there, they were hi gher in king eiders than in common eiders. Cadmium concentrations were lowe r in king eiders from the western arctic than in those from the east. In th e western arctic, cadmium concentrations did not differ between species. He patic mercury and zinc were higher in king eiders than in common eiders. Zi nc and selenium were higher in eiders from the western arctic than in those from the eastern arctic. Trace element concentrations in these two duck sp ecies were below published toxicity thresholds. Positive correlations in tr ace element concentrations in both species were found between total and org anic hepatic mercury, renal and hepatic cadmium as well as hepatic zinc, co pper, mercury, and cadmium. Body mass of common but not king eiders and spl een mass of both species were negatively correlated with mercury concentrat ions. In common eiders, the number of nematode parasites was positively cor related with total and organic mercury. Histopathological evidence of kidne y or liver lesions that are typical of trace metal poisoning was not found. We did not find evidence to support the hypothesis that trace metal exposu re may be contributing to adverse effects on the health of individuals of t hese species.