The Minnesota Department of Natural Resources (DNR) has confirmed reports of zebra mussels in Long Lake, near Park Rapids in Hubbard County, according to a July 23 news release.

A trained invasive species detector found a single zebra mussel on a plant rake when conducting routine sampling on Long Lake.

A subsequent dive search revealed two adult zebra mussels near the south public access and fishing pier on Long Lake. A DNR invasive species specialist said the specimens were breeding adults that were likely in the lake prior to this year.

Zebra mussels can compete with native species for food and habitat, cut the feet of swimmers, reduce the performance of boat motors and cause expensive damage to water intake pipes.

Sharon Natzel, member of the Long Lake Area Association (LLAA) board and AIS prevention coordinator for Long Lake, said, “Currently, our board of directors is working on our communications, informing lakeshore owners and lake users about the infestation. We are using email, social media, physical mailing and our kiosks at the south and north public accesses also.”

She continued, “We are encouraging lakeshore owners, their guests and Long Lake boaters to utilize the free Hubbard County decontamination station. Just call ahead for your convenient appointment at 218-252-6738. The decon station is at 812 Henrietta Ave. S., Park Rapids. It is only seven miles from the south access on Long Lake and three miles from the north access. The hot water kills the zebra mussels and invisible veligers and other AIS, too. It is important to contain the zebra mussels and prevent the spread in our lakes area.”

Natzel added, “We will try to determine zebra mussel localization in the lake in partnership with lakeshore owners, the DNR and others.”

The lake association is also looking into experimental treatment by the University of Minnesota AIS Research Center (MAISRC) and pilot treatment opportunities from the DNR.

“It is encouraging that the MAISRC mapped the zebra mussel genome in 2019. They have a three-year project on zebra mussels with low dose copper in two Minnetonka Bays. We are looking forward to an August webinar to learn more about the MAISRC project,” she said.

More information about the copper treatment is available at https://www.maisrc.umn.edu/sites/maisrc.umn.edu/files/zebra_mussels_low_dose_copper_website_copy.pdf.

Hubbard County AIS Coordinator Nick Macklem said, "The confirmation of zebra mussels in Long Lake is certainly disappointing news. We are currently monitoring the situation, and will be meeting with the DNR and Long Lake Association next week to discuss the options available for further monitoring and potential treatment. Long Lake will continue to be staffed regularly by our AIS inspectors for the remainder of the season, and will again be staffed next year on a similar basis. The inspectors are crucial in educating the public about the new discovery as well as informing boaters of AIS best management practices."

The DNR encourages people to contact a DNR aquatic invasive species specialist if they think they have found zebra mussels or any other invasive species.

“It’s helpful that lake users contact us when they find what might be a new invasive species to a lake,” said DNR Invasive Species Unit supervisor Heidi Wolf. “Early detection is important because it can help prevent spread to other lakes.”

Whether or not a lake is listed as infested, Minnesota law requires boaters and anglers to do the following:

  • Clean watercraft and trailers of aquatic plants and prohibited invasive species.

  • Drain all water by removing drain plugs and keeping them out during transport.

  • Dispose of unwanted bait in the trash.

Some invasive species are small and difficult to see at the access. To remove or kill them, take one or more of the following precautions before moving to another waterbody:

  • Spray with high-pressure water.

  • Rinse with very hot water (120 degrees for at least two minutes or 140 degrees for at least 10 seconds).

  • Dry for at least five days.

More information is available at mndnr.gov/ais.