Invasive algae found in Pimushe Lake near Bemidji

Starry stonewort can form dense mats and compete with native plants. It has never been eradicated from any U.S. lake.

June 26, 2021 at 9:02PM
Starry stonewort
(Star Tribune file/The Minnesota Star Tribune)

Starry stonewort, an invasive algae, has been found in Pimushe Lake, about 20 miles northeast of Bemidji.

The algae, first confirmed in Minnesota in 2015, has now been found in 17 of Minnesota's 11,842 lakes.

Pimushe Lake is near other Beltrami County lakes with confirmed populations of starry stonewort, but it's not directly connected to those lakes. The algae can spread when fragments aren't properly cleaned from trailered boats, personal watercraft and other water-related equipment.

The Minnesota Department of Natural Resources (DNR) will determine how much of the lake has been invaded by the algae and then work with the county and the Beltrami County Lakes and Rivers Association on possible management options such as hand pulling, herbicide application and other methods.

Starry stonewort can form dense mats and compete with native plants. It has never been eradicated from any U.S. lake, but treatment or careful removal can help reduce the risk of spread and provide nuisance relief for water-related recreational activities, according to the DNR.

about the writer

about the writer

Mary Lynn Smith

Reporter

Mary Lynn Smith is a general assignment reporter for the Star Tribune. She previously covered St. Paul City Hall and Ramsey County. Before that, she worked in Duluth where she covered local and state government and business. She frequently has written about the outdoors.

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