Skip to main content
Updated:
Original:

Unwelcome resident: The red swamp crayfish is Minnesota's newest invasive species

Two red swamp crayfish were discovered in a Minnesota lake, marking the first time the invasive species has been confirmed in the state.
Author:

Meet Minnesota's newest invasive species: the red swamp crayfish.

Two of them were found in Tilde Lake in northwestern Minnesota, and the state Department of Natural Resources said Thursday it's the first time the freshwater crustacean has been confirmed in a Minnesota lake.

The crayfish, which are typically found in Louisiana, compete with native species for habitat. Plus, they burrow, so it makes them "extremely difficult" to remove, and the habit can cause damage to levees, dams and water control structures.

DNR fisheries staff have removed the two crayfish from the lake, and they're looking to see if there are any others that have taken up residence.

How'd they get there?

Red swamp crayfish are a prohibited invasive species in Minnesota. It's illegal to import or have one if you don't have a proper permit, the DNR says.

Despite them being illegal, sometimes they get here.

The crayfish, which are red in color and can grow to be about 5 inches long, are popular bait to catch largemouth bass, and are also often purchased to use in aquariums – they're advertised as "freshwater lobster," according to the U.S. Geological Survey.

The DNR says retailers will often ship the crayfish to teachers for their classroom aquarium or to people who want them for a crawfish boil, without the buyer realizing it's illegal to have them.

“We recommend teachers check the prohibited invasive species list before committing to classroom aquarium animals,” Wolf said. “We also encourage teachers to discuss invasive species with their students.”

And when people are done with the animals, sometimes they're released or flushed down the toilet, the U.S. Geological Survey notes. That's when problems can really start, with the DNR noting many aquarium animals or plants can cause serious harm to plants and animals that are native to Minnesota.

Instead of just letting a crayfish go, the DNR says putting them in a plastic bag in a freezer for a day and then throwing them in the trash is the most humane way to dispose of them.

Next Up

unsplash cold winter breath dark

Hello, winter: List of the coldest wind chills in MN Monday morning

The state went from a relatively mild start of the season, to downright frigid wind chills.

deer

1 CWD-positive deer in Brainerd Lakes area, so surveillance will continue

The CWD monitoring measures were supposed to end after this year.

unsplash - visitor patient doctor hospital emergency - crop

MN program will train, hire 1,000 nursing assistants for long-term care

The facilities are facing a severe staffing shortage.

Minnesota State Fair - main gate day 2021

Minnesota State Fair reestablishes a police department

The fair had been contracting with the Ramsey County Sheriff's Office.

teacher, covid, masks, school

Minnetonka to consider removing middle school mask requirement

The school board has been impressed by vaccination rates among middle school students.

snow, plow

Friday winter storm could hit Twin Cities, southern Minnesota

Meteorologist Sven Sundgaard is already monitoring the forecast.

Sauk Rapids Middle School street view, Minnesota - November 2018_

Teen student arrested for threats toward MN middle school

The Sauk Rapids middle school and high school were closed Monday.

_DSC0318

Rally for trans child outed during Hastings school board race draws big crowd

Hastings has been in the spotlight since the child's family was featured in a CNN story.

chad davis arradondo flickr

Minneapolis police chief Medaria Arradondo to retire next month

He's overseen the MPD since mid-2017, following the killing of Justine Ruszczyk Damond

covid

Minnesota's COVID-19 update for Monday, December 6

The latest from the state health department.

2560px-Foo_Fighters_-_Southside_Festival_2019_4184_-_1

'Minneapolis, we're coming!!!': Foo Fighters announce rescheduled concert

The previously announced Huntington Bank Stadium was cancelled.

Related

List of waterways with invasive species grows

Just in time for Minnesota's warm-weather boating season, state conservation officials Thursday released a list of waterways newly discovered to be infested with invasive species such as Asian carp, zebra mussels and Eurasian milfoil. Added were nearly two dozen lakes and stretches of the Mississippi and St. Croix rivers.

Report: Millions spent annually fighting aquatic invasive species in Minnesota

A new report, commissioned by The Nature Conservancy, says Minnesota spends nearly $8 million a year fighting aquatic invasive species. Minnesota Public Radio notes the fight is complicated because there is no single method to control all the different types of invasive species.

Penalties double for invasive species violations

Tougher laws aimed to prevent the spread of aquatic invasive species, like zebra mussels and spiny waterfleas, go into effect Sunday, July 1 -- doubling fines for Minnesota boaters who are caught violating the rules. The Department of Natural Resources says about 20 percent of boaters are not taking the basic precautions to comply with the laws. The new fines range from $100 to $500 dollars.

DNR: Number of invasive species violations unacceptable

The Minnesota Department of Natural Resources says 20 percent of boaters screened this spring have violated laws to combat the spread of aquatic invasive species. The agency calls the rate unacceptable because the majority of violations could be avoided. DNR officers stepped up patrols last month and will continue through the summer.