Many Great Lakes residents are unaware they should limit some fish consumption to avoid harmful contaminants

MADISON – Despite the popularity of the Friday night fish fry in Wisconsin, only about half of the residents know there are limits to how much fish harvested from the Great Lakes basin they should consume each month to protect their health, according to a new study. 

The study showed that on average, those who caught their own fish were more aware of guidelines they should be following for how often to eat certain types of fish harvested from the Great Lakes and their tributaries, in order to avoid lead, PCBs, mercury and "forever chemicals." 

More:Here's where testing has located 'forever chemicals' in fish caught in Wisconsin waters

According to the study, which was conducted by researchers with the University of Wisconsin-Madison and the state Department of Health Services, 92% of the 4,452 adults surveyed said they had eaten fish within the last 12 months, with most of those surveyed reported eating fish they purchased. But because the fish were bought, instead of caught, those consuming the fish were likely to be less aware of the advisories. 

For example, lake whitefish, lake trout over 22 inches and yellow perch of any size from Lake Michigan shouldn't be consumed more than once a week, due to PCBs. In Lake Superior, whitefish and yellow perch can be eaten up to once a month, but lake trout should only be consumed once a month. 

Henry Anderson, one of the researchers involved in the study and a professor at the Nelson Institute of Environmental Studies at the University of Wisconsin-Madison, said to counter the lack of information, states in the Great Lakes region should focus on putting advisory information in areas they know people will be looking. 

"You don't go to the grocery store and go to the fish counter there and point to the salmon or sea bass or walleye and ask what the fish consumption advisory is," Anderson said. 

One of the ways to inform people is through the internet, pushing information to people, or by putting information on the approval page for a fishing license, as the Department of Natural Resources now does. Some insurance providers have started offering rewards to watch videos about fish consumption advisories, too, which is efficient, he said. 

But because most fish consumption advisories are aimed at infants and pregnant women, the best way to get information out is typically through medical providers dealing with those populations, Anderson said. 

"At the same time they talk to you about not drinking alcohol or using recreational drugs or smoking cigarettes, they'll say you might want to pay attention to fish advisories," he said. "Fish is good for the fetus, but you want to eat the fish lowest in contaminants." 

But even though they're at the highest risk, women, in particular, were less aware of advisories overall. 

In addition to making sure information is more readily available online and through health providers, people are going out into parks and other areas where people commonly fish to talk to them about advisories and how to protect themselves. 

"We're making headway on a lot of fronts," Anderson said. "But it's hard when someone catches a fish to tell them to throw it back. So we're telling them the right way to clean and cook it and to not eat too much."

The Great Lakes basin is made up of portions of Illinois, Indiana, Michigan, New York, Ohio, Pennsylvania and Wisconsin, as well as parts of Canada. According to Michigan Sea Grant, about 34 million people live in the basin — including about 8% of the U.S. population and about 32% of Canada's population. 

One of the most concerning contaminants in fish are PFAS, which, like mercury, stays in the meat of a fish, as opposed to the fat, which means there's really no way to avoid consuming the contaminant. In that case, Anderson said, limiting your intake of fish impacted by PFAS is the best way to keep yourself safe. 

PFAS, or per- and polyfluoroalkyl substances, are a family of man-made chemicals used for their water- and stain-resistant qualities in products like clothing and carpet, nonstick cookware, packaging and firefighting foam. The family includes 5,000 compounds, which are persistent, remaining both in the environment and human body over time.

PFAS have been linked to types of kidney and testicular cancers, lower birth weights, harm to immune and reproductive systems, and altered hormone regulation and thyroid hormones.

More:What the new federal health limits on 'forever chemicals' mean for Wisconsin

The compounds have been found in fish harvested from waters across the state, such as Angelo Pond, the bay of Green Bay and the tributaries that flow into it, many of the lakes in Madison, and the Pentenwell Flowage. 

Lake Superior is so far the only Great Lake to carry an advisory — for rainbow smelt. The advisory was issued in 2020 and said that the small fish should not be consumed more than once a month. 

Wisconsin also has advisories for mercury and PCBs, two other contaminants that commonly impact fish.

Even with concerns, fish remains a good source of omega-3 fatty acids, lean protein and vitamins. Fish also contains choline, which supports the development of a baby's spinal cord, as well as iron and zinc, which support children's immune systems. 

How can I reduce contaminant intake? 

The DNR has a number of guidelines that anglers (and those who enjoy eating fish) can follow in order to reduce the potential harm from eating contaminated fish. Keep in mind, though, that there are no known methods of preparing or cooking your fish that will reduce exposure to PFAS. 

Here are some: 

• Eat smaller, younger fish. Keep trophy fish in the water or on the wall and off your plate. 
• Space out fish meals to allow your body to get rid of some mercury.
• To reduce PCB exposure, remove fatty parts of the fish before cooking .
• Use a cooking method that allows fat to drip away, like broiling or grilling.
• Don't use fish drippings to prepare sauces or gravy.

For more information about fish consumption advisories in Lake Superior, Lake Michigan or other Wisconsin waters, visit www.dnr.wisconsin.gov. 

Laura Schulte can be reached at leschulte@jrn.com and on Twitter at @SchulteLaura.