starry stonewort

The Geneva Lake Environmental Agency and the state Department of Natural Resources are battling starry stonewort, an invasive species of algae that could disrupt Geneva Lake.

WILLIAMS BAY — Starry stonewort may be in Geneva Lake to stay, but with the right treatment program and a healthy lake plant population, it can be kept under control.

That is the assessment of Ted Peters, director of the Geneva Lake Environmental Agency, who issued a statement Sept. 9 on the status of the invasive plant effort.

Starry stonewort is an unwanted plant that can grow into thick bushes, creating disruption for a lake’s boating, fishing and other recreational uses.

The state Department of Natural Resources was at Geneva Lake on Sept. 5 to review the extent of the starry stonewort in the town of Linn’s Trinke Lagoon, where the invasive plant was first detected in August 2018.

Peters said the DNR has strongly recommended that the east bay of Trinke Lagoon, which has been largely taken over by starry stonewort, be chemically treated.

However, in the western portion of the lagoon, the starry stonewort is surrounded by native plant species and is not growing as quickly.

The DNR recommended that end of the lagoon be left untreated, Peters said.

“If we keep it (starry stonewort) in low densities, we can keep the local plant community healthy to help us fight it,” Peters said.

Since it was discovered in Trinke Lagoon, the plant has moved into other areas of Geneva Lake, with plants reported just outside the lagoon and another patch about a half mile east.

No treatment was suggested for those sites, Peters said. The plant diversity in those areas appear to be keeping the starry stonewort in check.

Chris Schultz has been a reporter for more than 40 years. He has been with the Lake Geneva Regional since 2010. He covers the Lake Geneva City Council and the Lake Geneva area schools.