Current Research | Apr 2, 2016

Researching Atmospheric Mercury and Freshwater Fish

After adding small amounts of tracer mercury to a small lake and its surrounding watershed for seven years (2001-2007), IISD-ELA researchers are continuing to monitor the ecosystem to see how long it takes for the mercury-contaminated lakes and fish populations to recover.

Mercury contamination of watersheds and fish by releases of mercury to the atmosphere from coal-fired power plants and smelters is an ongoing concern across the world. The ground-breaking Mercury Experiment To Assess Atmospheric Loading in Canada and the United States (METAALICUS) was the first whole-ecosystem mercury addition experiment to directly test the response of fish tissues to changing additions of mercury from rainfall. Small amounts of unique forms of mercury were added to an IISD-ELA lake and its watershed and were chemically-traced to fish tissues.

This study showed that mercury directly added to lake surfaces from rainfall will quickly accumulate in fish tissues, and that reduction of mercury in rain will decrease mercury in fish. Findings provide support for regulations proposed by the United States Environmental Protection Agency and Environment Canada to require power companies to add mercury scrubbers to their smoke stacks, at a potential cost of billions of dollars.

Click here to read more about what mercury does to fresh water, and what we are doing to reduce those impacts.