Indicators of wildlife health are important elements of a comprehensive approach for assessing and monitoring trends of methyl mercury (MeHg) contamination in the environment. River otters (Lontra canadensis) have been used as a model species for toxicological studies on the effects of MeHg bioaccumulation due to their position as an apex predator in aquatic systems and sensitivity to environmental disturbance. Although laboratory studies suggest that sublethal MeHg exposure may have detrimental effects on wildlife they are limited in their ability to reflect real world exposure and forecast population level effects. We used a series of data sets collected over a 7-year period for river otter populations in central British Columbia, Canada, to assess mercury concentrations (river otter fur) and measurements of population status and health relative to a lake with an inactive and reclamated mercury mine along its shoreline (Pinchi Lake). We found that mercury concentrations in river otter inhabiting Pinchi Lake were significantly higher than all other lakes in the study and were also high relative to other areas in Canada and the United States. We did not, however, detect significant differences between the two lakes in many of the population parameters measured. We discuss the knowledge gaps and challenges of identifying the effects of MeHg for wild populations of mammals, determining sensitive and appropriate methods for measuring these effects, and the implications of our results for monitoring the impacts of natural resources activities.

The Natural Resources & Environmental Studies Institute (NRESi) at UNBC hosts a weekly lecture series at the Prince George campus. Anyone from the university or wider community with interest in the topic area is welcome to attend. Presentations are also made available to remote participants through Livestream and Blue Jeans. Go to http://www.unbc.ca/nres-institute/colloquium-webcasts to view the presentation remotely.

Past NRESi colloquium presentations and special lectures can be viewed on our video archive, available here.