Atmospheric mercury contamination of remote aquatic ecosystems in Canada

The long-range atmospheric transport and deposition of metals, particularly mercury (Hg), into lakes has become a subject of increasing interest. In C anada, the sources of anthropogenic, atmospheric Hg are primarily considere d to be power stations in the United States and Europe. Increases in deposi tion of Hg have been recorded in lake sediment cores from many parts of Can ada. 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 anth ropogenic, atmospheric or natural. Where studied, the same applies to remot e lakes in other parts of the world. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved.