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Also: Lake St. Clair
  Rusty Crayfish
in the Great Lakes Region

What's New | Overview | Distribution Maps | Studies/Management Plans | Federal Resources | State/Provincial Resources
Current invaders:
Crustaceans: Rusty Crayfish | Spiny Water Flea
Fish: Goby (Round) | Goby (Tubenose) | Rudd | Ruffe | Sea Lamprey | White Perch
Mollusks: Quagga Mussel | Zebra Mussel
Plants: Curly-leaf Pondweed | Eurasian Watermilfoil | Phragmites (non-native) | Purple Loosestrife
Viruses: Viral Hemorrhagic Septicemia Virus (VHSv)
Potential invaders:
Fish: Asian Carp

[Invasive species home page]

What's New
Pursuers of alien invaders eat their fill of what they kill
The Wall Street Journal (11/4)
A tradition of Cajun cooking has emerged deep in the Northwoods of Wisconsin, spurred by the battle against the rusty crayfish.

Yup, those were crawdad claws on Chicago beaches
WBBM Newsradio 780 (12/22)
Anybody walking along the lake near the Montrose Dog Beach a week ago could easily have seen dozens if not hundreds of crab claws in the sand. "I believe those are from a rusty crayfish, what has been an invasive species in the Great Lakes region," says George Parsons, director of fishes at the Shedd Aquarium.

Scientists use trapping, predators to eliminate invasive species
St. Paul Pioneer Press (8/8)
A strategy to eliminate an invasive species of crayfish from a northern Wisconsin lake might provide a model for removing other nonnative species from the state's waterways.

Rusty not too trusty when it's in your lake
South Bend Tribune (1/22)
The rusty crayfish is native to the Ohio River Valley but it's raising havoc in the waters of the upper Midwest, where it's considered an invasive species.

Rusty crayfish added to Pennsylvania's illegal list
Pittsburgh Tribune-Review (10/16)
The Pennsylvania Fish and Boat Commission has added the rusty crayfish to a list of species that it is illegal to possess, sell, or transport in the state.

Rusty crawfish causing problems in Great Lakes
The Detroit News (9/11)
Scientists believe the rusty crawfish, a native of the Ohio River basin, came to the Great Lakes in bait buckets.

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Rusty CrayfishRusty crayfish (Orconectes rusticus) dwell in areas where rocks, logs or other debris can be used as cover; they do not, however, dig burrows, as do other crayfish. Habitat requirements also include permanent lakes or streams that provide suitable water quality year round.

This invasive crustacean is native to the Ohio River basin and portions of the states of Ohio, Kentucky and Indiana. They have spread to areas outside of their native range and established reproducing populations in areas of all Great Lakes states and the province of Ontario. They have also spread to areas beyond the Great Lakes basin, including east to New England, west to Colorado, Wyoming, and Oregon, and south to North Carolina and Tennessee.

Rusty crayfish can be difficult to identify as they are easily confused with other, similar species found in the region. Distinguishing characteristics of the rusty crayfish are their large claws and brown-colored bodies. They also exhibit dark, rusty spots on each side of their carapace, as though picked up with paint on one's forefinger and thumb. The spots may not always be present or well developed on rusty crayfish from some waters. The rusty's claw is grayish-green to reddish-brown and is smooth, with black bands at the tips.

Environmental impact: Upon establishment, rusty crayfish cause a range of ecological impacts. These include displacing and/or hybridizing with native crayfish, decreasing the density and variety of invertebrates, and reducing the abundance and diversity of aquatic plants that native fish use for cover and food. Several characteristics of the rusty crayfish provide a competitive edge in the invasion process. They are non-discriminatory, opportunistic feeders, consuming aquatic vegetation, worms, snails, leeches, clams, insects, other crustaceans, detritus, fish eggs and small fish. Their high metabolic rate allows feeding at two times the level of similarly sized native crayfish. Also notable is their ability to reproduce without both sexes present. One female carrying viable sperm can begin a new population if released into a suitable environment.

Photo: Jeff Gunderson, Minnesota Sea Grant

Rusty Crayfish Factsheet
For complete overview, identification and management:
View full, print-ready factsheet

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Distribution Maps
Geographic information on the location of aquatic invasive species sightings in the United States is made available through the U.S. Geological Survey, Nonindigenous Aquatic Species (NAS) program.

NAS Distribution Maps for the rusty crayfish

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Studies, Assessments and Management Plans
Assessing ecosystem vulnerability to invasive rusty crayfish (Orconectes rusticus) (2011)
Ecological Applications, 21(7)
Olden, J.D., M.J. Vander Zanden, and P.T. J. Johnson. Researchers modeled the exposure risk and the sensitivity of several Wisconsin lakes and streams to predict ecosystem vulnerability to species invasions.

Assessing the impacts of rusty crayfish on submergent macrophytes in a north-temperate U.S. lake using electric fences (2008)
The American Midland Naturalist
To experimentally reduce rusty crayfish densities in a lake, electric "fences" were used along with hand removal. The goals of this experiment were to both determine the impacts of crayfish on three species of macrophytes and to assess the effectiveness of electric fences as a control mechanism.

Fish predation and trapping for rusty crayfish (Orconectes rusticus) control: a whole-lake experiment (2006)
Canadian Journal of Fisheries and Aquatic Sciences, Vol. 63
C. Hein, B. Roth, A. Ives, and M.J. Vander Zanden. Using both direct trapping to remove organisms and fishing restrictions to increase predation stress, the authors suggest that the combination of both techniques is a useful control mechanism for established invasive crayfish populations.

Invasive Species Policy at the Regional Level: A multiple Weak Links Problem (2009)
Fisheries, Volume 34, Issue 8
J.A. Peters and D.M. Lodge. This study examines the weaknesses in region-wide regulation of invasive species. Using the rusty crayfish as a model organism, the authors identified a continuum of inconsistent regulations throughout the Great Lakes region, hindering the successful prevention of rusty crayfish and other invasives throughout the basin.

Potential corridors for the rusty crayfish, Orconectes rusticus, in northern Wisconsin (USA) Lakes: lessons for exotic invasions (Abstract) (2004)
Landscape Ecology (2004) 20
In this study, 35 lakes in northern Wisconsin were sampled to determine the presence of Orconectes rusticus, the rusty crayfish. The authors related the pattern of their occurrence to several parameters related to potential invasion routes that could influence the distribution of these crayfish in the lakes.

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U.S. and Canadian Federal Resources
Aquatic Invasive Species
Fisheries and Oceans Canada

Harmful Aquatic Hitchhikers: Crustaceans: Rusty Crayfish
Stop Aquatic Hitchhikers!

Rusty Crayfish
Aquatic Nuisance Species Task Force Species of Concern

Rusty Crayfish (Orconectes rusticus)
Ontario Invading Species Awareness Program

Rusty Crayfish (Orconectes rusticus)
National Sea Grant Network, Geographic Education Alliances - Exotic Aquatics on the Move

Rusty Crayfish Fact Sheet
U.S. Geological Survey - Nonindigenous Aquatic Species

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State and Provincial Resources
Alien Profile: Rusty Crayfish
Wisconsin Department of Natural Resources - Environmental Education for Kids (EEK!)

Rusty Crayfish
Illinois Environmental Protection Agency

Rusty Crayfish (Orconectes rusticus)
Michigan Department of Natural Resources

Rusty Crayfish (Orconectes rusticus)
Minnesota Sea Grant

Rusty Crayfish (Orconectes rusticus)
Minnesota Department of Natural Resources

Rusty Crayfish (Orconectes rusticus)
Wisconsin Department of Natural Resources

Rusty Crayfish Fact Sheet
Indiana Department of Natural Resources

Rusty Crayfish Fact Sheet
Pennsylvania Sea Grant

Rusty Crayfish Factsheet
Wisconsin Sea Grant

Rusty Crayfish: A Nasty Invader
Minnesota Sea Grant

Rusty “the Bully” Crayfish (Orconectes rusticus)
Sea Grant Nonindigenous Species (SGNIS)

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Updated: December 15, 2017
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