Zebra mussels join starry stonewort as unwanted species in central Minnesota's Lake Koronis

The Minnesota Department of Natural Resources announced Monday that Lake Koronis has a confirmed report of zebra mussels. A fishing guide snagged a zebra mussel on Lake Koronis on July 8. The lake became the first in Minnesota infested by starry stonewort when it was discovered in its waters in 2015.

Zebra mussels have been found confirmed in Lake Koronis.
Zebra mussels have been found confirmed in Lake Koronis near Paynesville in Stearns County.
Forum News Service file photo
We are part of The Trust Project.

PAYNESVILLE — Add zebra mussels to the list of aquatic invasive species in Lake Koronis.

The Minnesota Department of Natural Resources has confirmed a report of zebra mussels in Lake Koronis, near Paynesville in Stearns County, it was announced Monday.

The DNR reported that a fishing guide snagged an adult zebra mussel on a hook on July 8 and reported it.

DNR invasive species specialists searched the area and found no other zebra mussels. During a follow-up search, the DNR found one juvenile zebra mussel near the Lake Koronis Regional Park public water access.

More on AIS management efforts in Lake Koronis:
Starry stonewort was first discovered in Minnesota waters in Lake Koronis in 2015. It's now found in 19 Minnesota waterbodies. Lake Koronis is helping researchers understand how a changing climate may influence this invasive and how we can better manage it.
PAYNESVILLE - Starry stonewort might sound like the name of some obscure, grunge band. Yet the latest aquatic invasive species to reach Minnesota has the potential to be a big time menace and as notorious as other unwanted invaders like eurasian ...
PAYNESVILLE -- An aggressive, five-year campaign that is expected to cost over $800,000 is being launched to manage starry stonewort in Lake Koronis.Koronis and adjoining Mud Lake are first waters where the invasive species has been discovered in...

According to the DNR, 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.


Zebra mussels join starry stonewort as invasive aquatic species in Lake Koronis. Starry stonewort was first confirmed in Lake Koronis in 2015, making it the first lake in Minnesota to be infested by the single-strand alga.

According to West Central Tribune archives, in the past five years, the Lake Koronis Lake Association in partnership with the Minnesota DNR and others have invested $800,000 to manage starry stonewort. The invasive species has spread to more than 70 percent of the lake’s littoral area, according to the Lake Association.

Carli Wagner conducted research that monitored the rapid expansion of starry stonewort in Lake Koronis in the years 2017 to 2019. She holds starry stonewort collected during her research looking at its impact to native aquatic plants in three lakes.

The DNR reminds all lake users to abide by the law and help stop the spread of aquatic invasive species.

Minnesota law requires people to do the following:

  • Clean watercraft, trailers and equipment to remove aquatic plants and prohibited invasive species.
  • Drain all water and leave drain plugs out during transport.
  • Dispose of unwanted bait in the trash.
  • Never release bait, plants or aquarium pets into Minnesota waters.
  • Dry docks, lifts and rafts for 21 days before moving them from one water body to another.

People should contact a Minnesota DNR aquatic invasive species specialist at if they think they have found zebra mussels or any other invasive species.

More information is available on the aquatic invasive species page of the DNR website at

What to read next
DNR's annual surveys help determine fish populations, lake management, stocking strategies
Members Only
As outdoors activities go, this would be his last kick at the can for the foreseeable future. Chemotherapy was complete, but a stem cell transplant – an equally arduous step on his journey to recovery – awaited.
The third edition of "Rock Climbing Minnesota" details more than 1,100 routes and includes more voices in each description and more photos of women, people of color and LGBTQ climbers.
Retired teacher Larry Weber, a Barnum resident, is the author of several books, including “Butterflies of the North Woods,” “Spiders of the North Woods,” “Webwood” and “In a Patch of Goldenrods.” Contact him via Katie Rohman at