ST. PAUL, Minn. (AP) — Officials say initial results indicate a three-step treatment has been effective in ridding Christmas Lake in Shorewood of invasive zebra mussels.

The Department of Natural Resources says divers last week found no evidence of zebra mussels where they were discovered last August in the boat launch area of the popular west metropolitan area lake.

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DNR aquatic invasive species specialist Keegan Lund says they learned valuable information for responding to new infestations.

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Officials first treated the affected area with bacteria-based pesticide Zequanox in September, followed by a copper treatment in November, then injected 1,000 pounds of potash under the ice in December. The DNR needed special permission for the potash and copper treatments.

Christmas Lake will be monitored for several years to determine whether zebra mussels are present elsewhere in it.

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