Ruffe
Invasive SpeciesFound in 13 lakes
Ruffe is documented in 13 lakes across our dataset — 13 in Minnesota and 0 in Wisconsin. Each state's DNR maintains an official "infested waters" roster that triggers boat-launch decontamination protocols. 13 lakes — narrow enough that aggressive containment is still on the table. Most upper-Midwest invasives that established here did so quietly over a decade before anyone noticed, so a low number today is not a guarantee for tomorrow.
The presence of Ruffe does not directly change a lake's LakeGrade rubric score — the grade measures the water itself, not the species inhabiting it. But invasive presence is a meaningful adjacent signal worth reading alongside the grade.
Lakes with Ruffe
| Lake | County | State | Grade | Depth |
|---|---|---|---|---|
| Su18 Lake | Cook | MN | A | - |
| Su19 Lake | Cook | MN | A | - |
| Superior Lake | Cook | MN | A | - |
| Superior Lake | St. Louis | MN | A | - |
| Ls94 Lake | Lake | MN | A | - |
| Suseq32a Lake | St. Louis | MN | A | - |
| Seq044a Lake | Lake | MN | A | - |
| Suseq44a Lake | Lake | MN | A | - |
| Seq032a Lake | St. Louis | MN | A | - |
| Little Lake Deep | Cook | MN | B | - |
| Teal Lake Deep | Cook | MN | C | - |
| Little Lake Inlet | Cook | MN | F | - |
| Little Lake Landing | Cook | MN | F | - |
Frequently Asked Questions
How many lakes have ruffe?
Ruffe has been documented in 13 lakes, 13 in Minnesota and 0 in Wisconsin.
Does ruffe affect water quality?
Invasive species can significantly affect lake ecosystems. They may alter nutrient cycling, displace native species, and change water clarity. Lakes with ruffe should be monitored for changes in water quality over time.
Source: EPA National Aquatic Resource Surveys, 2026.