Starry Stonewort
Invasive SpeciesFound in 102 lakes
Starry stonewort is a relatively new invasive macroalga in {{stateName}}. It forms thick, hard-to-control mats and is much more difficult to remove than the older invasive plants. Documented in 102 lakes so far — a number that has grown over the past five years. 102 infested lakes is enough to require active prevention work statewide. The species is established in pockets but not ubiquitous.
The presence of Starry Stonewort 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 Starry Stonewort
| Lake | County | State | Grade | Depth |
|---|---|---|---|---|
| Pokegama Lake | Itasca | MN | A | 112 ft |
| West Sylvia Lake | Wright | MN | A | 97 ft |
| Rush Lake | Crow Wing | MN | A | 105 ft |
| Thunder Lake | Cass | MN | A | 95 ft |
| Thunder Lake | Cass | MN | A | 95 ft |
| Pokegama Lake | Itasca | MN | A | 112 ft |
| Walker Bay Lake | Cass | MN | A | - |
| Agency Bay Lake | Cass | MN | A | - |
| Kabekona Bay Lake | Cass | MN | A | 150 ft |
| Hen Lake | Crow Wing | MN | A | 105 ft |
| Geneva Lake | Walworth | WI | A | 135 ft |
| Silver Lake | Kenosha | WI | A | 44 ft |
| Lac la Belle Lake | Waukesha | WI | A | 45 ft |
| Pewaukee Lake | Waukesha | WI | A | 45 ft |
| Bear Lake | Waupaca | WI | A | 62 ft |
| Pine Lake | Shawano | WI | A | 35 ft |
| Pine Lake | Waukesha | WI | A | 85 ft |
| Green Lake | Washington | WI | A | 37 ft |
| Green Lake | Walworth | WI | A | 57 ft |
| Middle Lake | Walworth | WI | A | 40 ft |
| Upper Nemahbin Lake | Waukesha | WI | A | 60 ft |
| Golden Lake | Waukesha | WI | A | 44 ft |
| Mill Lake | Walworth | WI | A | 40 ft |
| Grass Lake | Shawano | WI | A | 52 ft |
| Pike Lake | Washington | WI | A | 45 ft |
| Okauchee Lake | Waukesha | WI | A | 90 ft |
| Pewaukee Lake | Waukesha | WI | A | 45 ft |
| Lower Phantom Lake | Waukesha | WI | A | 12 ft |
| Taylor Lake | Waupaca | WI | A | 58 ft |
| Geneva Lake | Walworth | WI | A | 135 ft |
| Big Cedar Lake | Washington | WI | A | 105 ft |
| Little Muskego Lake | Waukesha | WI | A | 65 ft |
| Waubeesee Lake | Racine | WI | A | 73 ft |
| Geneva Lake Site B | Walworth | WI | A | 135 ft |
| Okauchee Lake-Site No. 4-at Okauchee | Waukesha | WI | A | 90 ft |
| Okauchee Lake-Site No. 3-at Okauchee | Waukesha | WI | A | 90 ft |
| Long Lake | Kandiyohi | MN | A | 46 ft |
| Long Lake | Hubbard | MN | A | 135 ft |
| Benedict Lake | Hubbard | MN | A | 91 ft |
| Moose Lake | Beltrami | MN | A | 71 ft |
| Bemidji Lake | Beltrami | MN | A | 76 ft |
| Stump Lake | Beltrami | MN | A | 24 ft |
| Three Island Lake | Beltrami | MN | A | 25 ft |
| Beltrami Lake | Beltrami | MN | A | 50 ft |
| Middle Cullen Lake | Crow Wing | MN | A | 48 ft |
| Portage Bay Lake | Cass | MN | A | - |
| Traders Bay Lake | Cass | MN | A | - |
| Lake Winnibigoshish | Cass | MN | A | 69.8 ft |
| Tamarack Bay Lake | Cass | MN | A | 69.8 ft |
| Big Cedar Lake-North Site-Near West Bend | Washington | WI | A | 105 ft |
Showing 50 of 102 infested lakes.
Frequently Asked Questions
How many lakes have starry stonewort?
Starry Stonewort has been documented in 102 lakes, 56 in Minnesota and 46 in Wisconsin.
Does starry stonewort affect water quality?
Invasive species can significantly affect lake ecosystems. They may alter nutrient cycling, displace native species, and change water clarity. Lakes with starry stonewort should be monitored for changes in water quality over time.
Source: EPA National Aquatic Resource Surveys, 2026.