New Zealand Mud Snail
Invasive SpeciesFound in 7 lakes
New Zealand Mud Snail appears on state infested-waters lists for 7 surface waters. Boaters and anglers moving gear in or out of those lakes carry a clean-drain-dry obligation under state law. 7 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 New Zealand Mud Snail 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 New Zealand Mud Snail
| Lake | County | State | Grade | Depth |
|---|---|---|---|---|
| Superior Lake | Cook | MN | A | - |
| Superior Lake | St. Louis | MN | A | - |
| Little Lake Deep | Cook | MN | B | - |
| Teal Lake Deep | Cook | MN | C | - |
| Duluth Lake | St. Louis | MN | D | - |
| Little Lake Inlet | Cook | MN | F | - |
| Little Lake Landing | Cook | MN | F | - |
Frequently Asked Questions
How many lakes have new zealand mud snail?
New Zealand Mud Snail has been documented in 7 graded lakes: 7 in Minnesota.
Does new zealand mud snail affect water quality?
Invasive species can significantly affect lake ecosystems. They may alter nutrient cycling, displace native species, and change water clarity. Lakes with new zealand mud snail should be monitored for changes in water quality over time.
Invasives Found With New Zealand Mud Snail
Source: EPA National Aquatic Resource Surveys, 2026.