Starry stonewort confirmed in Upper Red Lake, Cass Lake

The Minnesota Department of Natural Resources has confirmed Minnesota’s third and fourth cases of the invasive algae starry stonewort, in Upper Red Lake in Beltrami County and Cass Lake, within the Leech Lake Reservation in Beltrami County.

starry_stonewort_pulled_from_upper_red_lake_0816_govdeliveryDNR invasive species staff confirmed a heavy growth of starry stonewort in a private harbor at the eastern edge of Upper Red Lake. The DNR is working with the property owner, local government and tribal officials to determine treatment options.

DNR staff also confirmed starry stonewort among heavy native plant growth in a northeast section of Cass Lake, near the Knutson Dam on the Leech Lake Reservation. Further investigation will reveal the extent of the infestation and potential treatment options on Cass Lake.

The second case of starry stonewort in Minnesota was confirmed earlier this month in Turtle Lake, also in Beltrami County. The first was confirmed one year ago in Lake Koronis, 185 miles due south of Turtle Lake.

“It is important that everyone who uses Minnesota lakes follows invasive species laws, whether the lake they use is infested or not,” said DNR Invasive Species Unit supervisor Heidi Wolf. “We strongly encourage anyone who is uncertain of the identity of a species and suspects it may be starry stonewort or any other aquatic invasive species to contact the DNR so we can check it out.”

Starry stonewort are grass-like algae that may produce dense mats, which could interfere with use of the lake. The invasive algae also may choke out native plants.

Starry stonewort is typically spread by lake users who transport fragments of the plant from an infested body of water. This new infestation is a reminder to boaters and anglers to follow Minnesota laws to prevent the spread of aquatic invasive species:

  • Clean aquatic plants and animals from watercraft.
  • Drain all water by removing drain plugs and keep drain plugs out while transporting watercraft.
  • Dispose of unwanted bait in the trash.

More information about aquatic invasive species and how to report them is available on the aquatic invasive species page.