What Contaminants Are in Minnesota Fish?
Fish can contain contaminants like mercury, PCBs (polychlorinated biphenyls) or dioxins that may harm health. Mercury can damage the nervous system and kidneys. Along with PCBs, it may cause developmental problems in children. PCBs and dioxins may cause cancer.
What Are the Health Concerns of Consuming Mercury?
Most contaminants in Minnesota fish are low but mercury remains a concern. All fish whether caught fresh or store bought contains some mercury. Mercury comes from natural and man-made sources and in the air which settles into lakes and rivers. It can then build up in fish. Mercury is found in the flesh of the fish and cannot be removed through cooking or cleaning. Young children, developing fetuses and breastfed babies are at greatest risk. Too much mercury may affect a child's behavior and lead to learning problems later in life.
Safe Consumption of Sport Caught Fish in Minnesota
For most people, one to two fish meals per week are optimal for balancing the health benefits with the health risks. If you are pregnant, planning to become pregnant, breastfeeding or have children under age 15, be more careful about the kinds of fish you eat and how often you eat fish.
Recommended Guidelines for Eating Minnesota Species
Choosing which fish to eat for meals is important to minimize exposure to mercury and other chemicals. Here are recommended guidelines:
- Eat smaller, younger fish.
- Eat more pan fish such as sunfish and crappies.
- Eat fewer predator fish like walleye or northern pike. Contaminants build up in large predator fish.
- Remove skin and trim fat to reduce PCBs.
- Broil, bake or grill fish to reduce PCBs.
- Mercury cannot be removed by cooking or cleaning. It gets into the flesh.
Fish Species With Fewer Contaminants
Five commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock and catfish.
Eat small fish or larger
fish with skin and fat removed.
What About Contaminants in Tuna?
In 2004, FDA and EPA fish advisories were upgraded to include albacore tuna and tuna steaks as fish with high mercury levels. "White" canned, albacore tuna has three times the mercury as "light" tuna.
What About Contaminants in Salmon?
What about salmon? Salmon is low in mercury, but studies show unacceptable PCB levels in fish feed given to farmed salmon. Until more research results are available, eat farmed salmon less frequently and wild salmon more often.
Where Can I Get the Consumption Advisory for My Lake?
The Minnesota Department of Health (MDH) releases annual advisories regarding eating fish caught in Minnesota's lakes and rivers. These advisories are based upon the levels of mercury and PCBs found in fish from Minnesota's lakes and rivers. The fish consumption advice given by the MDH is intended to keep the mercury in your body below levels that damage the nervous system. Fish from nearly 1,000 lakes and streams in Minnesota have been tested for contaminants. Lake survey reports and site-specific recommendations can be found on the MDH website.
To see if you and your family need to make changes in your fish-eating habits, view the advisories. By following the fish consumptions advisories you will get the health benefits of eating fish as well as reducing your exposure to the harmful effects of mercury.
Peer reviewed by Kathy Brandt 2015