Skip to main content
LakeQuality

New Zealand Mud Snail

Invasive SpeciesFound in 13 lakes

New Zealand Mud Snail appears on the {{stateName}} infested-waters lists for 13 surface waters. Boaters and anglers moving gear in or out of those lakes carry a clean-drain-dry obligation under state law. 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 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.

13
Total Lakes
13
Minnesota
0
Wisconsin

Lakes with New Zealand Mud Snail

LakeCountyStateGradeDepth
Su18 LakeCookMNA-
Su19 LakeCookMNA-
Superior LakeCookMNA-
Superior LakeSt. LouisMNA-
Ls94 LakeLakeMNA-
Suseq32a LakeSt. LouisMNA-
Seq044a LakeLakeMNA-
Suseq44a LakeLakeMNA-
Seq032a LakeSt. LouisMNA-
Little Lake DeepCookMNB-
Teal Lake DeepCookMNC-
Little Lake InletCookMNF-
Little Lake LandingCookMNF-

Frequently Asked Questions

How many lakes have new zealand mud snail?

New Zealand Mud Snail has been documented in 13 lakes, 13 in Minnesota and 0 in Wisconsin.

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.

Source: EPA National Aquatic Resource Surveys, 2026.