University of Minnesota researchers have reported limited success from an experiment to control an invasive weed in Lake Koronis near Paynesville.

Researchers from the Minnesota Aquatic Invasive Species Center have studying how to combat starry stonewort , which has been spread to 11 lakes across the state. They found that a combination of mechanical harvesting and algaecide greatly reduced the biomass of the plants in the treated area. And it was more effective than chemical treatment alone.

But they also found the tiny star-shaped structures on the weed called "bulbils" that can sprout into new plants remained viable after treatment. Preventing recovery will require further research.

Starry stonewort can grow dense mats, interfering with recreation and potentially displacing native species.

The paper was published this month in Lake and Reservoir Management.