More on Fish Mercury From the Great Lakes

Ojibwe tribal members in the northern Great Lakes region traditionally harvest walleye, a fish that commonly has concentrations of methylmercury that could be harmful. A group of researchers has produced new data and advice for the Native American population, ensuring that the potential risks are balanced with the potential benefits of eating the fish. The results are published in the latest issue of Integrated Environmental Assessment and Management. Walleye are at the top of the aquatic food chain, typically accumulating mercury in their tissues to potentially dangerous levels. Leading this study, the Great Lakes Indian Fish and Wildlife Commission (GLIFWC) has produced walleye consumption advisories depicted on maps since 1996 to help tribal members reduce exposure to methylmercury due to fish consumption.

In creating updated advisories, however, the GLIPWC was careful to balance the risks of walleye consumption with the clear health benefits of eating fish. The harvest and consumption of fish are culturally important activities of the Ojibwe tribes. Walleye harvest has increased since the 1980s when federal courts reaffirmed the tribes’ rights to hunt, fish, and gather in territories ceded to the United States through treaties signed in 1837 and 1842 in the present-day states of Michigan, Minnesota, and Wisconsin.

The new data, collected through a risk-based approach, provide consumption advice for 293 of the 449 lakes assessed in the region. Most of the advisories for the lakes carry a recommendation of no more than four meals per month for the general population and no more than one meal per month for the sensitive population. The approach used here could be adapted for other regions.

To read the entire study, go to http://www.allenpress.com/pdf/ i1551-3793-4_1_118.pdf