Starry stonewort

Starry stonewort, an invasive species with the potential to damage wildlife habitats and impede recreational activity, took root in a Geneva Lake lagoon this summer (File photo/Regional News).

TOWN OF LINN — The Geneva Lake Environmental Agency wants to stop an invasive plant from infesting Geneva Lake, but the undertaking could cost more than $120,000.

Directors of the Williams-Bay based environmental agency want to dredge sediment from a lake lagoon to control its population of “starry stonewort,” an invasive algae that could cause damage to the lake if left unchecked.

“Here we have an epidemic of a weed that could change the whole habitat of the lake. Then we don’t have a lake anymore,” said Lamar Lundburg, chairman of the agency’s board of directors.

Starry stonewort is difficult to control because its reproductive organs, or “bulbils,” embed themselves in sediment. There is no known method of eradication.

Ted Peters, director of the Geneva Lake Environmental Agency, said the best control method would be to hydraulically dredge and remove two feet of sediment from the lagoon’s floor, with the goal of removing embedded bulbils from the site.

“I think what we have here is a good situation where we can control it. It’s very new, and very low-density,” Peters said. “I think if we attack this quick and aggressively, it may not get out into the lake.”

The agency hopes to begin dredging as soon as April, but Peters estimates the cost will exceed $120,000.

At a Nov. 20 meeting, the agency’s board of directors agreed to pursue more sources of funding, including partnerships with other organizations, and surcharges for fishing tournaments.

Lundburg and others recommended seeking donations from nearby property owners and recreational lake users.

The agency first received reports of starry stonewort this summer in a lagoon near Trinke Estates in the town of Linn, on the south shore of Geneva Lake.

After officials surveyed Geneva Lake vegetation samples in October, they confirmed the invasive species was present, although it was isolated in about a half-acre of the lagoon.

Since the lagoon is connected to the main lake, however, the infestation has the potential to spread if environmentalists do not take action.

This is the first known population of starry stonewort in Walworth County.

If left uncontrolled, the unwanted algae can take over breeding areas for fish, overcome native vegetation and disrupt a lake’s recreational activities.

The Geneva Lake Environmental Agency plans to meet in December with leaders of the Trinke Estates property owners association to discuss a response plan.

“I do feel like we’re probably going to go the route of dredging, and hopefully Trinke will go with us,” Peters said.

To further reduce costs, the agency is applying for a $20,000 grant from the state Department of Natural Resources.

The agency plans to begin fundraising by January.

If officials fail to raise enough money to dredge the lagoon, they could also chemically treat and mechanically harvest the plant.

Peters, however, said this technique may not be enough; herbicides would kill the plants, but the bulbils in the sediment would survive.

“They’re going to come right back up, and you’re gonna be constantly treating it,” Peters said. “It keeps coming back.”

In the meantime, the agency plans to work on education and outreach programs to ensure lake users are cleaning vegetation off their boats.

Peters, who suspects a boat carried starry stonewort into Geneva Lake, said cleaning watercraft is crucial for preventing the spread of invasive species and maintaining the quality of the lake.