LivewellIllinois · Knox County · Lake
Lake McMaster
Is the fish you caught here safe to eat? Below is every consumption advisory on file for Lake McMaster, by species and size, in plain English — plus what's legal to keep.
4 species with advisories · contaminants: Mercury, PFOS
Illinois also has statewide guidance
Illinois publishes rules that apply to lakes across the state — 1 recommendation covering 1 species — in addition to anything listed for Lake McMaster below.
Strictest statewide rule: All Other Species — For women of childbearing age and children under 15: limit to one meal per week due to elevated Mercury.
What's safe to eat from Lake McMaster
Black Crappie
| Size | Who | Guidance |
|---|---|---|
| All sizes | General population | Limit to one meal per week due to elevated PFOS. |
Source: official advisory· updated 2026-11-06
Bluegill
| Size | Who | Guidance |
|---|---|---|
| All sizes | General population | Limit to one meal per week due to elevated PFOS. |
Source: official advisory· updated 2026-11-06
Largemouth Bass
| Size | Who | Guidance |
|---|---|---|
| All sizes | General population | Limit to one meal per week due to elevated PFOS. |
Source: official advisory· updated 2026-11-06
Walleye
| Size | Who | Guidance |
|---|---|---|
| All sizes | General population | Limit to one meal per week due to elevated Mercury. |
| Women of childbearing age and children under 15 | For women of childbearing age and children under 15: limit to one meal per month due to elevated Mercury. |
Source: official advisory· updated 2026-11-06
Is it legal to keep?
These are Illinois's statewide limits — a water-specific rule may override them. Always verify the current regulations before keeping a fish.
| Species | Size | Daily limit | Open season | Keep season |
|---|---|---|---|---|
| Largemouth Bass | 14" min | 6 | Year-round | Same as open |
| Walleye | 14" min | 6 | Year-round | Same as open |
| Muskellunge | 36" min | 1 | Year-round | Same as open |
| Northern Pike | 24" min | 3 | Year-round | Same as open |
| Black Crappie | — | 25 | Year-round | Same as open |
| Channel Catfish | — | 6 | Year-round | Same as open |
Official rules: Illinois — Illinois DNR