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LakeQuality
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Rusty Crayfish

Invasive speciesRecorded in 233 lakes

Rusty Crayfish is documented in 233 lakes across our dataset — 233 in Wisconsin. Each state's natural-resources agency maintains an official "infested waters" roster that triggers boat-launch decontamination protocols. A 233-lake footprint means Rusty Crayfish prevention has shifted from "stop the spread" to "manage the new normal." Watercraft-inspection programs at boat launches and shoreline-management practices on individual lakes are doing most of the active prevention work.

The presence of Rusty Crayfish 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.

233
Lakes with records
233
Wisconsin

Lakes with Rusty Crayfish

LakeCountyStateDepth
Green LakeGreen LakeWI236 ft
Geneva LakeWalworthWI135 ft
Lac Courte Oreilles LakeSawyerWI90 ft
Round LakeSawyerWI74 ft
Sand LakeSawyerWI50 ft
Grindstone LakeSawyerWI60 ft
Lake St CroixSt. CroixWI60 ft
Boulder LakeVilasWI23 ft
Lake NoquebayMarinetteWI51 ft
Spider LakeVilasWI43 ft
Pickerel LakeForestWI19 ft
Pickerel LakeOcontoWI10 ft
Beaver Dam LakeBarronWI106 ft
North Turtle LakeVilasWI58 ft
Silver LakeForestWI20 ft
Plum LakeVilasWI57 ft
Whitefish LakeOneidaWI33 ft
Round LakeOneidaWI15 ft
Bass LakeOneidaWI20 ft
Bass LakeOcontoWI40 ft
Clear LakeRuskWI74 ft
Pioneer LakeVilasWI27 ft
Little Spider LakeVilasWI23 ft
Bone LakePolkWI43 ft
Lake LucerneForestWI73 ft
Bear LakeForestWI20 ft
Bear LakeOneidaWI20 ft
Bear LakeWaupacaWI62 ft
Long LakeBayfieldWI28 ft
Long LakeChippewaWI101 ft
Lake MetongaForestWI79 ft
Birch LakeVilasWI45 ft
Pike LakeWashingtonWI45 ft
Anderson LakeVilasWI63 ft
Anderson LakeOcontoWI40 ft
Red Cedar LakeBarronWI53 ft
Pewaukee LakeWaukeshaWI45 ft
High LakeVilasWI36 ft
Butternut LakeForestWI42 ft
Paya LakeOcontoWI40 ft
Island LakeRuskWI54 ft
Island LakeOneidaWI26 ft
Lake EmilyPortageWI35 ft
Big LakeVilasWI30 ft
Papoose LakeVilasWI65 ft
Kentuck LakeVilasWI40 ft
Lower Eau Claire LakeBayfieldWI41 ft
Deer LakePolkWI46 ft
Boot LakeOcontoWI38 ft
Little Crooked LakeVilasWI30 ft

Showing 50 of 233 lakes with a record.

Frequently Asked Questions

How many lakes have rusty crayfish?

Rusty Crayfish is recorded in 233 measured lakes: 233 in Wisconsin. 233 of them carry a state infested-waters listing or an established population.

Does rusty crayfish 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 rusty crayfish is worth reading alongside its clarity number rather than through it.

Invasives Found With Rusty Crayfish

Chinese Mystery Snail

Co-occurs in 148 lakes · 469 total

Banded Mystery Snail

Co-occurs in 111 lakes · 341 total

Curly-Leaf Pondweed

Co-occurs in 90 lakes · 387 total

Purple Loosestrife

Co-occurs in 78 lakes · 242 total

Zebra Mussel

Co-occurs in 39 lakes · 609 total

Flowering Rush

Co-occurs in 9 lakes · 54 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.