Atmospheric mercury contamination of remote aquatic ecosystems in Canada

Abstract

The long-range atmospheric transport and deposition of metals, particularly mercury (Hg), into lakes has become a subject of increasing interest. In Canada, the sources of anthropogenic, atmospheric Hg are primarily considered to be power stations in the United States and Europe. Increases in deposition of Hg have been recorded in lake sediment cores from many parts of Canada. Where Hg input to lakes from local sources in Canada has been reduced, concentrations in lake sediments and lake biota have declined. However, in many remote lakes, fish consumption advisories are still in effect for Hg. Debate continues over the sources of this mercury, whether long-range anthropogenic, atmospheric or natural. Where studied, the same applies to remote lakes in other parts of the world.