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Despite Promising Treatment, Zebra Mussels Found In Christmas Lake

MINNEAPOLIS (WCCO) -- After a new treatment appeared to rid Christmas Lake of zebra mussels, the Minnesota Department of Natural Resources says the invasive aquatic species is back.

Crews first treated the affected area of the lake in Shoreview with a bacteria-based pesticide called Zequanox in September. Then, there was a copper treatment in November, and another in December, when crews injected 1-thousand pounds of potash under the ice.

The DNR initially reported no sign of zebra mussels in the lake, until recently when 10 were discovered outside of the treated area.

After 10 years of living on Christmas Lake, the Dougan's favorite family activity -- boating -- hasn't changed. They hoped the 260 acre lake wouldn't change either, but it did last year, when the first zebra mussels were discovered.

"Our homeowner's association actually paid for inspections for a couple years to try and make sure we kept them out," Jack Dougan said.

Heidi Wolf of the DNR says zebra mussels impact everyone, not just those living on the lake.

"They attach to any hard surface, getting inside your boat, fouling your motor," Wolf said.

The invasive species also disrupts the food chain of a lake and can cut up swimmers' feet.

That's why Jack Dougan was relieved when the DNR caught it early enough in Christmas Lake to use a mixture of bacteria-based pesticides that were only used twice before in U.S. lakes.

It was all clear until this week.

"We just don't know so we'll keep monitoring closely," Wolf said.

Zebra mussels must be discovered in the extreme early stages if crews can have a chance to stop the spread. After the treatment, DNR inspectors search the ecosystem extensively for any sign of the mussels.

"They did scuba diving, wading, and boat searching around the whole lake," Wolf said.

Some 200 man-hours later, officials confirmed the treated area was still clear, but they discovered 10 zebra mussels in another part of the lake.

DNR representatives say they don't know if more zebra mussels are lurking -- as they could be in their microscopic beginning stages -- so the best bet is prevention.

"It's a degrading of why we live in Minnesota -- for the lakes," Dougan said. "We want to make sure we protect them and do the right things."

DNR officials and those living on Christmas Lake ask visitors to properly clean their boats before entering the water. The DNR doesn't have any plans to treat the new impacted area of Christmas Lake, but say the new mixture they used is still the best tool they have.

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