Mercury content in the fur of sea otters (Enhydra lutris) from the Commander Islands

The sea otter (Enhydra lutris) is a keystone species in the ecosystem which is currently in depression in Russia. The objectives of this study were to: (1) establish if the sea otters from the Commander Islands have hazardous levels of mercury (Hg) in their fur; (2) assess Hg pollution in sea otters during a period of high abundance and population depression; (3) identify the age and sex differences in sea otters by Hg content. The sea otters were classified from no to low risk for Hg health effects. Differences in Hg content during periods of low and high population size were not statistically significant. Hg concentrations in adult sea otters were significantly higher than in the young, and higher in males than in females. This study presents the first data on Hg content in sea otters' fur and the first estimate of Hg contamination for the Commander Islands population.

Automated summary

This study aims to investigate mercury (Hg) levels in the sea otters in Russia and understand the impact of Hg contamination on different age and sex groups. The sea otters showed low risk levels of Hg contamination, and there were no significant differences in Hg levels during different population size stages. Hg concentrations were significantly higher in adult sea otters compared to young otters, and higher in males than females. This study provides the first data on Hg content in sea otters' fur and estimates of Hg contamination for the Commander Islands population.