Trace Element Concentrations in Bearded Seals (Erignathus barbatus) Near Red Dog Mine Compared to Other Locations in Alaska

Abstract

To determine if bearded seals (Erignathus barbatus) harvested near a zinc and lead mine (Red Dog, Alaska , USA) by subsistence hunters from Kivalina, Alaska, were as safe to eat as bearded seals from other locations in Alaska, we compared 19 trace element concentrations in liver tissue. Liver concentrations from nine bearded seals harvested near the Red Dog Mine (RDM) port site were compared with 15 bearded seals from two reference sites (Hooper Bay and Little Diomede, Alaska, USA). Concentrations did not differ by gender, but we found statistically significant trends in concentrations of cadmium, mercury, manganese, selenium, and vanadium with age. Arsenic and copper were the only elements found to be more concentrated in the liver of bearded seals harvested near RDM than in the other locations. The predominant form of arsenic in marine mammals is known to be a nontoxic organic form, not the toxic inorganic form, and copper is an essential element. Although elevated near RDM, neither element was found at concentrations that presented health risks. We found no evidence that bearded seals harvested near RDM were less safe to eat or that trace element concentrations were greater than those found in bearded seals harvested elsewhere in Alaska or Canada.