Invasive Algae Starry Stonewort Confirmed in Spider Lake in Hubbard County

Size comparison of a starry stonewort bulbil next to a one-cent piece. (Credit: DNR)

The Minnesota Department of Natural Resources has confirmed the presence of the invasive algae starry stonewort in a lake near Nevis in Hubbard County.

A contractor conducting early detection surveys contacted the DNR after finding what they believed to be starry stonewort in Spider Lake. DNR staff confirmed it was starry stonewort and are planning further surveys to assess the distribution and density of the invasive algae.

The DNR says that since starry stonewort was first found in 2015, it has been confirmed in 39 water bodies in the state. Starry stonewort can form dense mats, which can interfere with recreational uses of a lake and compete with native plants. The algae primarily spreads when fragments have not been properly cleaned from water-related equipment.

Starry stonewort has never been eradicated from any U.S. lake or river, but treatment or careful removal from water bodies can help reduce the risk of spread and relieve associated nuisance impacts. Early detection is key to effective management.

More information on how to identify starry stonewort and steps to stop it from spreading to more water bodies can be found on the DNR website.