Zebra mussels found in Watab Lake, connected to Rossier Lake, in Stearns County

Three connected lakes in Stearns County have been designated as infested waters after the Minnesota Department of Natural Resources (DNR) confirmed the presence of invasive zebra mussels in Watab Lake — connected to Rossier Lake — north of St. Joseph. Watab Lake should not be confused with Big Watab Lake south of Avon.

The confirmation came after a Watab Lake resident reported finding what appeared to be zebra mussels on the ladder of a swimming raft early last week. When DNR staff investigated, they found zebra mussels attached to several other pieces of recreational equipment as well.

Because Watab Lake is connected to Rossier Lake and Lower Watab Lake, those waters will be designated as infested waters, as well as the Watab River downstream of Watab Lake to the confluence with the Mississippi River. Designation does not mean each body of water is confirmed to be infested, but that zebra mussels have been detected in a lake accessible by boat and spread is likely between connected waters. 

“This is the first confirmed case of zebra mussels in a Stearns County lake, and it underscores the need for continued diligence in complying with the state’s invasive species laws,” said Christine Jurek, DNR invasive species specialist. “Before leaving a water access, remove all aquatic plants and animals, drain water-related equipment, remove drain plugs from bilge, livewell and baitwell and dispose of unwanted bait in the trash.”

Moving docks, boat lifts and other water-related equipment from one lake to another can move invasive species as well. State law requires that all docks, boatlifts and swim rafts removed from any lake, river or stream be dried for 21 days and all aquatic plants and animals such as zebra mussels and Eurasian watermilfoil be removed from the equipment before it is placed in another body of water.

Early detection is critical in preventing the spread of invasive species. Fall provides a good reminder for lakeshore owners to inspect all water-related equipment when it is removed from the water at the end of the season.

People who find something they suspect is a zebra mussel or other aquatic invasive species should take a photo or keep the specimen, and report it to the nearest DNR invasive species specialist. DNR staff will be working with area residents on the connected waters of Watab Lake, Rossier Lake and Little Watab Lake this fall to further document the extent of zebra mussels in these waters.

More information about zebra mussels and other aquatic invasive species is available on the DNR website at www.mndnr.gov/AIS.