Increasing cadmium and zinc levels in wild common eiders breeding along Canada's remote northern coastline

• Cd and Zn analyzed in common eider (Somateria mollissima) liver tissue in Canadian Arctic from sites spanning 3000 km.
• ~ 300% increase in concentrations observed over ~ 20 years
• Levels of both elements considered high and near levels thought to pose concerns for wildlife health

The common eider (Somateria mollissima) is an abundant sea duck breeding around the circumpolar Arctic, and is an important component of subsistence and sport harvest in some regions. We determined hepatic cadmium (Cd) and zinc (Zn) concentrations in the livers of breeding females sampled during three time periods including 1992/3, 2001/2 and 2008 at three sites spanning 53.7°N–75.8°N in the eastern Canadian Arctic. At all sites, concentrations of both Cd and Zn increased ~ 300% over this time period. The reasons for this rapid increase in concentrations are unclear.