We have recently confirmed the presence of another contaminant in park waters, the highly toxic element mercury. Preliminary results from a recently completed three-year inland lakes fishery inventory showed that several inland lakes had northern pike with mercury levels which exceeded the Michigan Fish Consumption Advisory level of 0.50 parts per million (PPM). These findings quickly spurred an interest in further study, and through a national funding program associated with Canon, USA, Inc the park received funding to conduct more intensive studies to document the mercury levels throughout the food web. Because of funding constraints the study is focusing on Sargent Lake, one of the lakes with higher mercury levels.

Scientists are examining mercury levels in the water, sediments, plankton, fish, and Common Loons of Sargent Lake. The research extends to examining mercury levels in deer mice within the Sargent Lake watershed and in moose teeth across the park. Finally, in an effort to consider mercury at a broader regional level, scientists will assess mercury levels within human baby teeth from children from the Upper Peninsula of Michigan. The project is being completed with several partners, including Michigan Technological University, the University of Wisconsin-Madison, and Biodiversity Research Institute. The University of Michigan’s Air Quality Lab will provide information on the amount of mercury reaching the park through the atmosphere, and the US Geological Survey will provide information on the amount of mercury found naturally in the bedrock and soils within the park. Taken together, this initial research should provide a good picture of mercury levels throughout the food chain in this island ecosystem.