Brittle Naiad: 13 Lakes with Records

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 change a lake's clarity, phosphorus or algae readings, which measure the water itself, not the species living in it. Invasive presence is still worth reading alongside those numbers.

Lakes with records

Minnesota

Wisconsin

Lakes with Brittle Naiad

Lake	County	State	Depth
Lac Lavon Lake	Dakota	MN	32 ft
Crooked Lake	Adams	WI	56 ft
Round Lake	Hennepin	MN	37 ft
Bryant Lake	Hennepin	MN	45 ft
Ann Lake	Carver	MN	45 ft
Mitchell Lake	Hennepin	MN	19 ft
Lotus Lake	Carver	MN	29 ft
Lake Puckaway	Green Lake	WI	5 ft
Mason Lake	Adams	WI	9 ft
Buffalo Lake	Marquette	WI	8 ft
Susan Lake	Carver	MN	17 ft
Staring Lake	Hennepin	MN	16 ft
Lake Butte des Morts	Winnebago	WI	9 ft

Frequently Asked Questions

How many lakes have brittle naiad?

Brittle Naiad is recorded in 13 measured lakes: 8 in Minnesota, 5 in Wisconsin. 13 of them carry a state infested-waters listing or an established population.

Does brittle naiad affect water quality?

An established invasive population can change how a lake works — altering nutrient cycling, displacing native species, and shifting water clarity. Clarity is the one to watch: filter-feeders can make water read clearer on a Secchi disk without any drop in nutrient loading, so a lake with brittle naiad is worth reading alongside its clarity number rather than through it.

Invasives Found With Brittle Naiad

Eurasian Watermilfoil

Co-occurs in 8 lakes · 792 total

Curly-Leaf Pondweed

Co-occurs in 5 lakes · 387 total

Zebra Mussel

Co-occurs in 3 lakes · 609 total

Banded Mystery Snail

Co-occurs in 2 lakes · 341 total

Zebra Mussel

Co-occurs in 2 lakes · 609 total

More on invasive species and lake health

Zebra Mussel Spread: How Many Lakes Are Affected?

Zebra mussel counts from the lakes LakeQuality tracks, the counties that show up most often, and the Clean, Drain, Dry rules that still matter.

Lake Water Quality Explained: What the Readings Mean

How nutrient and algae readings are read against EPA ecoregion condition classes, what each class means in the water, and why a clean reading is not a clearance.

What to Check Before Buying Lakefront Property

Before you buy lakefront, check the water: clarity trend, nutrient impairment, algae advisories, invasive species, and depth — a data-backed checklist.

Source: EPA National Aquatic Resource Surveys, 2026.