MATTAWAN, Mich. — The Michigan Department of Natural Resources, or DNR, has confirmed the presence of invasive red swamp crayfish in Van Buren County.
The invasive crayfish was found in an outdoor muskellunge rearing pond at Wolf Lake State Fish Hatchery in Mattawan, according to the DNR.
Hatchery staff found the carcasses of two unusual crayfish in the collection basket of Wolf Lake Hatchery Pond 20 after stocking Thornapple Lake and Lake Hudson.
Crews deployed crayfish traps in Pond 20 and two adjacent ponds, resulting in the capture of one live, positively identified red swamp crayfish in Pond 20.
Native to the southern U.S., red swamp crayfish have been prohibited in Michigan since 2014.
They are considered invasive in the state due to their ability to aggressively outcompete native crayfish for food and habitat, their high reproductive rate, and their destructive burrowing along shorelines that can banks and infrastructure.
Red swamp crayfish were first detected in Michigan in 2017, with simultaneous discoveries in Sunset Lake in Kalamazoo and a drainage pond in Pontiac.
Infestations have been found in Kalamazoo, Livingston, Macomb, Oakland, Van Buren and Wayne counties. Officials believe the infestations are a result of the release or escape of aquarium pets, live bait, or live crayfish brought for boils.
Out of caution, the DNR is developing a monitoring plan for both lakes, and will alert lake users to report any sightings of the invasive crayfish.
More information on red swamp crayfish, including identifying characteristics, can be found here.