FARGO – A biological survey of the Red River in June detected zebra mussel larvae for the first time in several locations north of Wahpeton, the North Dakota Game and Fish Department said in a media release.
A "significant" number of the zebra mussel larvae, called veligers, were found in the river at six cities: Wahpeton, Abercrombie, Fargo, Grand Forks, Drayton and Pembina.
Fred Ryckman, an aquatic nuisance species coordinator for the Game and Fish Department, said in a statement that "the results are certainly surprising in that so many veligers were detected at each of the six sampled sites.
"And it's even more incredible considering that in similar sampling over the past several years we've only detected about a half dozen veligers in total."
The results from the study, which took place June 23 and 24, were unusual because they showed, for the first time, zebra mussels veligers in larger numbers and living downstream from Wahpeton.
The Game and Fish Department said people should be careful transporting water out of the Red River because the mussel larvae are microscopic.
"There really isn't anything we can do to remove the veligers or any adult zebra mussels from the river," Ryckman said, "but we can be on alert and do everything we can to prevent them from being moved to other bodies of water."
Zebra mussel veligers were recently found in the Red River at the Canadian border, and the mussels have historically been found near Wahpeton in the Otter Tail River, Ryckman said.