Starry stonewort discovery prompts efforts to stop algae

Minnesota's first confirmed infestation of starry stonewort has generated a coordinated response to stopping the invasive grass-like algae in Lake Koronis.

In August, the Minnesota Department of Natural Resources confirmed the presence of the macro algae, the St. Cloud Times reported. Since then, tens of thousands of dollars and hours of research have been funneled into efforts to stop the spread of starry stonewort.

The state DNR is ramping up boat inspections, the Koronis Lake Association is preparing to launch a $828,600 pilot project and University of Minnesota researchers are planning lab experiments.

The DNR will provide a watercraft inspector and to survey boat access within 10 to 30 miles of Lake Koronis.

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Unlike the DNR, the lake association is focusing on eradication instead of management, taking a more aggressive approach. The group's plans include mechanical and hand removal followed by herbicide.

"(Our) focus is on stopping the spread," said Kevin Farnum, who serves on the Koronis Lake Association board, the Stearns County Coalition of Lake Associations and the Stearns County AIS Committee. "We don't want it to come out of Koronis. We don't want to be the mother lode of starry stonewort for the state."

University researchers at the Minnesota Aquatic Invasive Species Research Center plan to experiment on starry stonewort that collects from the lake and grows in the lab in an effort to see how it spreads and what herbicides are most effective.

"The goal of all of this is to come up with scientific findings that can then be translated on the ground, that can lead to solutions to control," said Daniel Larken, a faculty member and researcher at the center.

The invasive algae occupies about 250 acres on Lake Koronis, primarily in the bay off of the DNR's Minnesota Highway 55 access, and scattered in other spots throughout the lake. The DNR is monitoring its growth in the bay and at a couple of sites on the lake.

The DNR also plans to treat the 4-acre site at the Highway 55 launch with an herbicide to reduce the biomass.

Starry stonewort is native to Asia and Europe. Besides Minnesota, it has also been confirmed in New York, Michigan, Indiana and Wisconsin.