Selenium, mercury, arsenic and cadmium in the lifecycle of the dunlin, Calidris alpina, a migrant wader.

Migrant waders accumulate pollutants from their marine moulting and wintering grounds in Western Europe. In examining the possible consequences on the reproduction of the Dunlin (Calidris alpina), it was found that no adverse effects are to be expected from selenium, mercury, arsenic or cadmium. Though selenium is accumulated in very high concentrations in the kidney, after the bird's departure from the marine environment for the freshwater breeding areas, levels decline rapidly. Mercury exposure in Western Europe is not excessive, as shown by the relatively low levels in the summer plumage. Feather element concentrations proved to be a useful indicator of the different moulting and wintering areas used by the birds.