Best Way to Attack Starry Stonewort Is to Hunt It Down and Catch It Early
“If you can find those plants early on, you have a good chance of stopping it — early detection can pay off big,” says Becker County Aquatic Invasive Species Coordinator Karl Koenig.
Published: Saturday, March 11, 2023 12:00 pm
By: Nathan Bowe
Detroit Lakes — While flowering rush and zebra mussels are familiar aquatic nuisances in this area, and wild radish can cause serious burns to those clearing brush on land, the next big invasive concern for area lakes is hardly a plant at all — it’s a big floating algae with a fairy dust name – starry stonewort.
It clogs up lakes by forming dense mats at the water’s surface, shouldering out native plants and leaving native animals without suitable shelter, food and nesting habitat, according to the Minnesota DNR.
It also costs a fortune to combat starry stonewort once a lake is infested, Becker County Aquatic Invasive Species Coordinator Karl Koenig told the County Board on Feb. 7.
“A huge amount of money is spent in some parts of the state to clean lakes for boating and fishing — and the next year it grows back again,” Koenig said.
“The scariest part of the (county AIS) report was how many people came from lakes with starry stonewort to Becker County lakes,” said Commissioner Barry Nelson.
There were 16 such boats from starry stonewort lakes that came directly to Detroit Lake last year. Nine such boats visited Lake Melissa; 19 visited Bad Medicine, 10 visited Many Point Lake.
Other lakes that saw boats coming directly from starry stonewort lakes include Cotton (3), Sallie (4), Floyd (2), Ida (2), Island (5), Straight (3), Height of Land (5), Two Inlets (8), Tamarac (1), Lief (1), Toad (4) and Boot (1).
In all, 117 boats came to Becker County lakes directly from starry stonewort lakes last year, Koenig said.
That particular invasive species came from Europe and Asia and — like so many others — was unintentionally released into the Great Lakes through cargo ship ballast water.
In Minnesota, it was first found in Lake Koronis in Stearns County in 2015, and there are now at least 19 lakes in Minnesota listed as infested with starry stonewort. That includes lakes as close as Wolf Lake in Hubbard County and Lake Beltrami in Bemidji.
When it was discovered in Grand Lake in Stearns County in 2017, the local lake association and DNR teamed up in a rapid response to remove the small patch of starry stonewort, according to the Minnesota Aquatic Invasive Species Research Center at the University of Minnesota.
That now looks like the best approach to keeping a lake free of it, Koenig said.
With that in mind, the county AIS program is focusing on finding it early. “Monitoring and observing,” Koenig told commissioners. “We go to access sites or high-traffic sites and look at the plants that are there,” he said. “If you can find those plants early on, you have a good chance of stopping it — early detection can pay off big.”
Small patches of starry stonewort can be removed by hand, without any chemicals or herbicides, and that seems to be an effective way to keep a lake free of it, he said.
Koenig does visual lake inspections himself, and his program also provides for scuba surveys of lakes to try to nip invasives in the bud.
“It's a proactive step to maintain boating and water quality on their lakes — the public sees good value in that,” he said.
“You can’t eradicate starry stonewort once it takes over a lake,” Nelson said, voicing particular concern for the Cormorant lakes chain.
“That whole chain of lakes is on our radar for starry stonewort,” Koenig said. “We're looking for it.”
The county has information on which lakes are most in danger of various invasive species, and the county deploys its 30-some boat inspectors accordingly. “Lake associations sometimes use this data to buy extra inspection services from us,” Koenig said. “It’s worth $10,000 or $20,000 to them to lower the risk.”
The local aquatic invasive species program is an offshoot of the Becker Soil and Water Conservation District. Becker County receives about $345,000 a year from the state for the program, with the money going towards watercraft inspection and decontamination, outreach and education, monitoring, control grants and program administration.
tags: Environmental Impact, Michigan
