BISMARCK, N.D. — Young zebra mussels have for the first time been found in the Red River north of Wahpeton, according to North Dakota’s Game and Fish Department.

A survey conducted by the department in June found a “significant” number of zebra mussel larvae called veligers at Wahpeton, Abercrombie, Fargo, Grand Forks, Drayton and Pembina.

The invasive species compete with native species, clog water intakes and can even sink docks and buoys with their weight. Zebra mussel larvae were found in the Wahpeton area in 2010, 2011 and 2014, but not north of the city. The Red River flows north.

The only known population of zebra mussels within the Red River basin is an established population of adults in the Otter Tail River watershed in Minnesota, upstream from where the Otter Tail and Bois de Sioux rivers join to form the Red at Wahpeton-Breckenridge. Biologists now wonder if there are undiscovered colonies of adult zebra mussels elsewhere within the Red River watershed.

Boaters, anglers and others should be careful about transporting any water away from the Red, said Fred Ryckman, aquatic nuisance species coordinator for Game and Fish.

“There really isn’t anything we can do to remove the veligers or any adult zebra mussels from the river,” he said. “But we can be on alert and do everything we can to prevent them from being moved to other bodies of water.”

People also are being asked to report any suspected adult zebra mussels that they find.