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Defending Rose Lake: DNR tries radical cure for mussels

Zebra mussels found in Rose Lake will be treated with three doses of copper sulfate.1 / 2
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The Minnesota DNR is carrying out a first-of-its kind, fast attack on the zebra mussels recently found in Rose Lake in between Frazee and Vergas.

The invasive species with a reputation for killing off fish populations and destroying beaches with their sharp shells were found in the lake on Sept. 28.

According to the DNR, the zebra mussels were likely brought in from a boatlift that was transported from an infested lake -- likely Lake Lizzie, they say.

"There was an individual that helped this person take his boat lift out of the water and saw the zebra mussels and said, 'you need to call a conservation officer'," explained DNR Invasive Species Specialist Nathan Olson, "and the individual said 'ah, don't worry about it', and as he drove away that other person called and alerted us to it."

Now, that one person with that one boatlift has caused an entire community of lake-lovers and community leaders to scramble to the shore of Rose Lake to watch as the DNR attempts a 1-2-3 punch of copper sulfate.

Treatment began Thursday morning, with a 10-acre area being treated.

Where the infested boatlift and dock once were, now sits a 10,000 square foot enclosure that DNR officials are saturating with the chemical.

"We know that we are going to inadvertently kill some aquatic plants and fish in that area, but it's a price we're willing to pay to try to obliterate the zebra mussels," said Olson, who added that the chemical is not harmful to waterfowl or humans.

Copper sulfate has been used in the past to try to remove zebra mussels on other Minnesota lakes, and while they've been successful in killing them, they've always come back.

Once a lake is fully -infested, there currently is no effective way to get rid of them.

This time, however, DNR officials are optimistic that it could work, given the fact that these zebra mussels seem to be isolated in one spot and are still juveniles, meaning they are not mature enough to reproduce.

The DNR will be applying three treatments to the area once a week for three weeks.

This has all involved crossing their fingers and hoping for results.

"This will be groundbreaking if it works," said the president of the Otter Tail County Coalition of Lake Associations, Jeff Stabnow, in a statement. "It just may be the first successful extermination of zebra mussels from an open body of water in Minnesota, maybe even North America and perhaps the world."

DNR officials say they will continue to monitor the lake, but won't have a firm idea of whether or not it worked for at least two years.

"These buggers are hard to kill," said Olson, "because they can actually sense the chemical in the water and they close up their shells."

Meanwhile, they will also continue to investigate the person who brought the zebra mussels into the lake.

"I'm fairly certain it was unintentional, but there still needs to be some consequences," said Olson, "so we're still investigating and determining what we're going to do."

Homeowners around Rose Lake also stood around the treatment area Thursday morning, disgusted with the carelessness that they say could potentially kill their lake life.

"We were terribly disturbed," said Rose Lake property owner Laurel Mahan, "This has been such a beautiful, clean, clear lake. I've got three grandchildren who love to swim in here, so it's just disturbing."

"Not only that," adds fellow Rose Lake homeowner Larry Madson, "but Rose Lake flows into Long Lake, which flows into the Ottertail River system, which flows into the Pine Lakes, so being upstream, if Rose Lake cannot be eradicated, these other lakes are going to have problems, too."

This is also the fear of Frazee Mayor Hank Ludtke.

"We have a lot of pristine lakes around here, so this is a very scary situation to have these things so close," said Ludtke, "this can affect economic development, eco-tourism, fishing ... If this hits hard here, people are going to have to wear shoes on the beach and fishing won't be worth a darn. And eventually it will affect property values big time."

This incident alone is costing the state of Minnesota thousands of dollars.

In addition to what the DNR says is a substantial number of man-hours it took to inspect the lake, the three rounds of treatment costs close to $14,000.

"That's an expensive mistake," said Becker County COLA Vice President Terry Kalil, "and if this treatment doesn't work and this lake is truly infested, the impact is in the millions."

Kalil says although she's glad to see the quick reaction, she doesn't believe 'reacting' is what everybody should be doing.

"I think we need to do more in enforcement and education. Instead of being reactive, why don't we close the public accesses to those lakes that are infested?" Kalil questioned, "Why aren't we doing more inspections and doing more in decontamination?"

Although not everybody seems to agree on how to execute the battle against invasive species, those that care always implore others to care.

"We need more education on this," said Olson, "and we need more people to care because even if it doesn't seem like zebra mussels are having a big impact now, it will seem like it in 20 years. So everybody needs to do their part and do the right thing as they go from lake to lake."