Study shows half of Great Lakes residents don’t know about fish advisories

Some 5 milliion people may be eating more fish than recomended by health advisories, according to research by the University of Wisconsin-Madison.

cooler of smelt
Only about half the residents of the Great Lakes region know about fish consumption advisories, like the ones in place for eating Lake Superior smelt like these, according to a University of Wisconsin study.
Bob King / File / Duluth News Tribune
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Only about half the people living in the Great Lakes region are aware of fish consumption advisories that warn people to limit their meals of fish, according to a study from the University of Wisconsin-Madison.

The study, published in the journal Science of the Total Environment, also found that an estimated 5 million people across the region exceeded the general recommended fish intake of two meals, or 12 ounces per week, as suggested by the Environmental Protection Agency for all fish, including those purchased in stores.

Minnesota and Wisconsin also have state advisories for fish caught in the states that warn people to avoid some fish and limit meals of others due to high levels of mercury, PCBs (polychlorinated biphenyls) and PFAS (per- and polyfluoroalkyl substances) chemicals. Those at highest risk are children and fetuses, so the strongest warnings are aimed at women of child-bearing years and their children.

The study estimated about 62 million people live in the region. Some 92% had eaten fish, but most were eating store-purchased fish, which fall under the general advisory, including tuna and other ocean fish. An estimated 18.6 million adults consumed fish caught from lakes and rivers.

The study found women, people of color, younger residents and those with lower education levels were less aware of fish advisories, and thus more prone to eat more than the recommended amount. That's likely in large part because most warning information has historically been aimed at anglers on the big lakes, usually older white males.


PFAS in Duluth area lakes, Lake Superior smelt already an issue.

Still, the study found that, even though licensed anglers were more aware of advisories, they lacked the details needed to decide which species were safe to eat. For example, in most cases, the warnings urge people to avoid larger fish, which accumulate more toxins over time. But in Lake Superior, warnings also exist even for tiny smelt.

Eating fish is healthy because it's a lean source of protein with vitamins and omega-3 fatty acids. But eating too much contaminated fish is bad because they can pass on the toxins to humans.

PFAS is linked to higher blood pressure and cholesterol levels, decreased vaccine response in children, lower birth weight and cancer, according to the Agency for Toxic Substances and Disease Registry.

PCBs are historical industrial pollutants. Their levels are generally declining after being phased out of use many decades ago, but PCBs are probable carcinogens.

Mercury is a potent neurotoxin that can cause many health issues, even death. Methylmercury poisoning might result in loss of peripheral vision, lack of coordination, impaired speech and hearing and muscle weakness, according to the EPA.

John Myers reports on the outdoors, natural resources and the environment for the Duluth News Tribune. You can reach him at
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