USGS news room:
“Methylmercury contamination is decreasing in some lakes in northern Minnesota as a result of reduced mercury pollution, according to a U.S. Geological Survey study. Mercury from man-made pollution is converted in lakes and wetlands to methylmercury, a toxic form of mercury that accumulates in fish.
The study also found that levels of mercury, sulfate and hydrogen ion in precipitation decreased from 1998 to 2012 in northern Minnesota. These decreases likely resulted from reduced atmospheric pollution in the U.S. and Canada, and may have contributed to the reduced methylmercury contamination in the [Voyageurs National] park’s lakes.”
J Stephen Conn
Do or do not. There is no try.
