Fish Consumption Guide · Updated 2026-10-04
What WI DNR/DHS guidance says
Heidmann Lake, Kewaunee County, WI — fish consumption guidance is set by Wisconsin DNR and Department of Health Services (DHS). Statewide Choose Wisely guidance applies, plus any waterbody-specific advisory in the DNR Fish Consumption Advisory Query.
How much to eat: general population
WI DNR/DHS sets these limits for people who are not pregnant, not planning a pregnancy and not breastfeeding, and who are 15 or older. They are applied here to the species recorded at Heidmann Lake in WI DNR survey data.
| Species | Size | How Much to Eat |
|---|---|---|
| Mid-mercury species (Largemouth Bass, other bass) | all sizes | 4 servings per month |
| Northern Pike | all sizes | 4 servings per month |
How much to eat: children under 15, and people pregnant or breastfeeding
WI DNR/DHS publishes a second set of limits for children under 15 and for people who are pregnant, may become pregnant, or are breastfeeding. Some are the same as the ones above and some are lower.
| Species | Size | How Much to Eat |
|---|---|---|
| Mid-mercury species (Largemouth Bass, other bass) | all sizes | 1 serving per month |
| Northern Pike | all sizes | 1 serving per month |
Check the Official Source
For waterbody-specific advisories (PFAS, PCBs, dioxins, lake-specific mercury) beyond the statewide rules, always consult the official Wisconsin DNR Fish Consumption Advisory Query for Heidmann Lake.
Official WI DNR Advisory →Why Mercury Builds Up in Some Fish
Mercury enters lakes from atmospheric deposition (coal-fired power plants are the dominant US source), local geology, and historical mining or industrial activity. In water, it converts to methylmercury, which bioaccumulates: small fish absorb it, larger fish eat smaller fish, and apex predators end up with the highest concentrations.
That's why walleye, northern pike, muskellunge, and lake trout carry the strictest advisories — they're top predators that live a long time. Smaller, faster-growing fish like bluegill, crappie, and yellow perch have much lower mercury and can usually be eaten weekly.
In Minnesota, the Northeast (St. Louis, Lake, Cook counties — the Arrowhead) has higher background mercury due to mining legacy and forested wetlands that favor methylmercury production. MN MDH applies 2-inch shorter length cutoffs for walleye and pike in this zone.
For PFAS ("forever chemicals"), the contamination is point-source: industrial discharges, military firefighting foam, paper mill waste. Bay of Green Bay (WI) and select Northeast MN lakes have the most active PFAS advisories. PFAS is not well-correlated with mercury, so a lake with low Hg can still have a PFAS advisory.
Frequently Asked Questions
Is it safe to eat fish from Heidmann Lake?
Whether fish from Heidmann Lake are safe to eat is a call for WI DNR/DHS and the county health department; this page reports what their published guidance says. Under WI DNR/DHS statewide guidance, panfish from Heidmann Lake are listed at 1 meal per week. Heidmann Lake, Kewaunee County, WI — fish consumption guidance is set by Wisconsin DNR and Department of Health Services (DHS). Statewide Choose Wisely guidance applies, plus any waterbody-specific advisory in the DNR Fish Consumption Advisory Query. For waterbody-specific advisories beyond the statewide rules, check the official WI DNR/DHS query linked on this page.
What is the most restrictive species at Heidmann Lake?
Walleye and northern pike are the most restricted species at Heidmann Lake under WI DNR/DHS guidance. Mercury accumulates with size, so length cutoffs apply.
Who is in the "sensitive population" for fish consumption?
Minnesota MDH defines it as children under 15, and people 15 or older who are pregnant, may become pregnant, or are breastfeeding or plan to breastfeed. Wisconsin DHS uses a similar definition and includes people who may become pregnant in the next three to five years. Each agency publishes a separate table of meal limits for this group, and both tables are on this page for the states where we carry them.
Why are walleye and northern pike more restricted than panfish?
Mercury bioaccumulates up the food chain. Walleye, pike, musky, and lake trout are top predators that eat smaller fish, concentrating mercury in their flesh. Bluegill, crappie and sunfish eat insects and zooplankton and carry much less. Yellow perch is the exception among the panfish: Minnesota MDH holds it to one serving per month for everyone, and puts it on the avoid list for children under 15 and for people who are pregnant or breastfeeding.
What about PFAS in fish from Heidmann Lake?
PFAS (forever chemicals) are an emerging concern in fish, especially near industrial/military sites and in the Bay of Green Bay (WI), Yahara chain (WI), and select Northeast Minnesota lakes. WI DNR has issued PFAS advisories for specific waters and is expanding sampling. Check the official query for current PFAS-specific guidance for Heidmann Lake.
Related
This page applies statewide guidance from Wisconsin DNR and Department of Health Services (DHS) to fish species documented at Heidmann Lake in DNR survey data. It does not replace lake-specific advisories published by health agencies. Always check the official query (linked above) for the most current guidance, especially for PFAS, PCBs, and dioxins which can require waterbody-specific advice. Last updated: 2026-10-04.