Mercury in Hair of Muskox on the Seward Peninsula

Abstract

Problem statement: Muskoxen (Ovibus moschatus) are distant relatives of sheep (Caprinae) and have roamed the Arctic for a million years, with populations reaching North America between 150,000 and 250,000 years ago. Muskox populations could be negatively influenced by climate change and increased exposure to contaminants. Since the snow depth is a critical factor in their ecology, effects could occur throughout their distribution. Muskox typically feed on plants on hilltops and upper slopes where shrubs are increasing at the expense of graminoid and lichen species. Besides changes in plant species composition, wildfires and flooding, as well as renewed mining developments, can lead to an increased incidence of total Hg (THg) bioavailability. Approach: In this survey THg concentrations were measured in the hair of muskox at several sites on Seward Peninsula of Alaska, USA. Results: Muskox exhibited mean THg levels in the hair of 29.3 ng g^-1 for the west base of Mineral Mountain, 28.6 ng g^-1 for Nature Hill and 23.0 ng g^-1 for the camp at Deering. Means for THg levels at Anvil were 35.2 ng g^-1 at the top, 31.8 ng g^-1 on the southwest slope and 29.9 ng g^-1 at the base. Qiviut from two muskox at Anvil and Mineral Mountain possessed lower THg values than when compared to their guard hair (32.9 and 44.8 ng g^-1, respectively). Conclusion: These current THg levels are relatively low and helping establish a baseline for Hg exposure in muskoxen.