Levels of cadmium and mercury in the hair of Atlantic walruses (Odobenus rosmarus rosmarus) from Svalbard, Norway

Hair samples of 15 adult male Atlantic walruses (Odobenus rosmarus rosmarus ) collected from anaesthetized individuals at Svalbard, Norway, were analys ed for cadmium and total mercury. The mean level of cadmium was 0.860 +/- 0 .321 mu g/g dry weight (median = 0.811, range = 0.349-1.51 mu g/g dry weigh t) and the mean level of mercury was 0.235 +/- 0.100 mu g/g dry weight (med ian = 0.251, range = 0.121-0.424 mu g/g dry weight). Levels of cadmium and mercury in hair of walruses from other areas are not known. Both cadmium an d mercury levels in hair of walruses from Svalbard are relatively low compa red to the levels found in the hair of other marine mammal species. It has been documented from a number of marine species, including marine mammals s uch as ringed seals and polar bears, that both cadmium and mercury levels a t Svalbard are lower than in other areas. It is uncertain as to what degree levels in hair reflect levels in internal organs in walruses. In rare and highly endangered species or populations tissue samples can be difficult to collect. In walruses, it is possible to collect hair from anaesthetized in dividuals or at the haul-out sites during moult, to monitor heavy metal lev els of the population.