Identifying Causes of Exceptionally High Mercury in Fish
Most mercury in Minnesota waters is deposited from the atmosphere as a byproduct of burning coal and other compounds. Once in the environment, mercury can convert to a form called methylmercury where it bioaccumulates up the food chain from microscopic plants and animals to fish and then to humans and wildlife that consume the fish. The first step in solving the problem of mercury in fish is reducing the sources of mercury entering waters. Significant efforts are underway to reduce the amount of mercury released from human sources such as smokestacks and wastewater discharge, which will address the majority of the mercury entering the environment. However, there are a percentage of watersheds where mercury appears to have enhanced concentrations due to factors that are particular to the ecology of a watershed and not mainly driven by the amount of mercury entering the watershed. The Minnesota Pollution Control Agency is using this appropriation to better understand the probable causes of high mercury levels in fish in watersheds where atmospheric deposition alone does not account for the high mercury levels in order to determine what additional measures beyond source reduction can be taken to reduce mercury levels in those watersheds.
$743,000 the second year is from the trust fund to the commissioner of the Pollution Control Agency to quantify the probable causes of high mercury levels in fish within the Roseau River and two tributaries of the Red River of the North by comparing mercury movements within watersheds to understand the drivers of mercury biomagnifications in the food web of rivers with similarly high mercury levels and to guide further mercury reduction initiatives. This appropriation is available until June 30, 2017, by which time the project must be completed and final products delivered.
Click on Work Plan under Project Details.
Click on Work Plan under Project Details.