LivewellOhio · River
St. Mary's River
Is the fish you caught here safe to eat? Below is every consumption advisory on file for St. Mary's River, by species and size, in plain English — plus what's legal to keep.
4 species with advisories · contaminants: Mercury
Ohio also has statewide guidance
Ohio publishes rules that apply to rivers across the state — 11 recommendations covering 11 species — in addition to anything listed for St. Mary's River below.
Strictest statewide rule: Flathead Catfish, Over 23" — Limit to one meal per month due to elevated Mercury.
What's safe to eat from St. Mary's River
Freshwater Drum
| Size | Who | Guidance |
|---|---|---|
| All sizes | General population | Limit to one meal per month due to elevated Mercury. |
Source: official advisory· updated 2026-09-22
Largemouth Bass
| Size | Who | Guidance |
|---|---|---|
| All sizes | General population | Limit to one meal per month due to elevated Mercury. |
Source: official advisory· updated 2026-09-22
Northern Pike
| Size | Who | Guidance |
|---|---|---|
| All sizes | General population | Limit to one meal per month due to elevated Mercury. |
Source: official advisory· updated 2026-09-22
Saugeye
| Size | Who | Guidance |
|---|---|---|
| All sizes | General population | Limit to one meal per month due to elevated Mercury. |
Source: official advisory· updated 2026-09-22
Is it legal to keep?
These are Ohio'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 | 12" min | 5 | Year-round | Same as open |
| Smallmouth Bass | 12" min | 5 | Year-round | Same as open |
| Walleye | 15" min | 6 | Year-round | Same as open |
| Muskellunge | 30" min | 1 | Year-round | Same as open |
| Northern Pike | — | 6 | Year-round | Same as open |
| Channel Catfish | — | 6 | Year-round | Same as open |
Official rules: Ohio — Ohio DNR