Brittle Naiad
Invasive SpeciesFound in 13 lakes
Brittle Naiad appears on state 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 Brittle Naiad 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 Brittle Naiad
| Lake | County | State | Grade | Depth |
|---|---|---|---|---|
| Lac Lavon Lake | Dakota | MN | A | 32 ft |
| Crooked Lake | Adams | WI | B | 56 ft |
| Ann Lake | Carver | MN | B | 45 ft |
| Round Lake | Hennepin | MN | C | 37 ft |
| Bryant Lake | Hennepin | MN | C | 45 ft |
| Lake Puckaway | Green Lake | WI | C | 5 ft |
| Mitchell Lake | Hennepin | MN | D | 19 ft |
| Lotus Lake | Carver | MN | D | 29 ft |
| Susan Lake | Carver | MN | D | 17 ft |
| Staring Lake | Hennepin | MN | D | 16 ft |
| Lake Butte des Morts | Winnebago | WI | F | 9 ft |
| Mason Lake | Adams | WI | F | 9 ft |
| Buffalo Lake | Marquette | WI | F | 8 ft |
Frequently Asked Questions
How many lakes have brittle naiad?
Brittle Naiad has been documented in 13 graded lakes: 8 in Minnesota, 5 in Wisconsin.
Does brittle naiad affect water quality?
Invasive species can significantly affect lake ecosystems. They may alter nutrient cycling, displace native species, and change water clarity. Lakes with brittle naiad should be monitored for changes in water quality over time.
Source: EPA National Aquatic Resource Surveys, 2026.