A $423,000 grant from the National Fire Sciences Program was given to The University of Minnesota, USGS and the Forest Service to study fish before and after fires in the Superior National Forest. Of interest to them are mercury levels.
They believe that forest fires are responsible for their contamination. They are focusing their study in the Boundary Waters Canoe Area, where many fires are in the process of being lit to clear excess dead wood from a devastating storm in 1999.
As mercury is released from power plants, it settles in the forest and is absorbed by vegetation over the years. Large amounts of contaminated ash can be flushed into lakes and streams immediately following a forest fire.