MINNEAPOLIS (WCCO) — The Minnesota Department of Natural Resources says water samples show a “substantial” amount of zebra mussel larvae in the state’s portion of Lake of the Woods.

READ MORE: DNR: Zebra Mussels Discovered In Iron Range Mine Pit

Three samples were taken on the lake — situated on Minnesota’s borders with the Canadian provinces of Ontario and Manitoba — yielding up to almost 200 larvae, also known as veligers.

DNR research scientist Gary Montz says it is not clear if the larvae can survive in the sixth-largest freshwater lake in the United States.

READ MORE: U Of M Scientists Map Zebra Mussel Genome, Opening Possibility To Weaken The Invasive Species

“It is possible that calcium levels or other factors might prevent propagation,” Montz said.

Another invasive aquatic species, the spiny water flea, was found in the lake 12 years ago.

The DNR is again urging people to “Clean, Drain, Dispose” after boating in any Minnesota lake — which is state law:

  • 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.

Go to the DNR’s website for more information on combating invasive species.