Zebra mussel find in Green Lake leads to infested water designation
SPICER — The Minnesota Department of Natural Resources designated Green Lake as an infested water body on Monday due to the discovery of a single, adult zebra mussel on a dock post on the southeast corner of the lake on July 21.
The downstream waters of Lake Calhoun are also being designated as infested as a precaution, according to the DNR.
The designation on Green Lake means that efforts to prevent the spread of aquatic invasive species will be ramped up around the lake and at neighboring waters.
The hours that inspectors are scheduled to work at public accesses on the lake will be increased, as will efforts to enforce the state’s laws aimed at controlling the spread of aquatic invasive species.
A second, power washer unit is being placed this week at the Kandiyohi County Park 5 boat access on the north side of the lake, according to Nick Brown, aquatic invasive species specialist with the Minnesota DNR.
A power washer is already available at the Saulsbury Beach access in Spicer as the result of a cooperative venture by the Green Lake Property Owners Association and City of Spicer.
The designation comes with some encouraging news. Sampling work and water testing conducted after the single, adult zebra mussel was confirmed have failed to find any signs of other zebra mussels or the microscopic veligers or larvae they produce, according to Ann Pierce, section manager for the DNR’s division of ecological and water resources.
She said the DNR will continue to monitor the lake and work with lakeshore owners. The designation will be re-examined if no evidence of zebra mussels is found in the next five years.
The adult zebra mussel was found in about four feet of water, and was believed to be two years old. The dock’s owner said the dock had been used only in Green Lake.
Brown said DNR personnel devoted two days to snorkeling in areas where it was discovered to see if other adult zebra mussels were attached to rocks, vegetation or other docks and manmade structures.
DNR workers also pulled nets capable of trapping the microscopic veligers in waters near the discovery site, as well as in the middle of the lake.
He and Pierce cautioned that the inability to find veligers or adult zebra mussels does not mean a clean bill of health. Only on-going monitoring will help answer whether other zebra mussels are present and reproducing, they noted.
Brown said the DNR will be urging lakeshore residents to help the DNR monitor the situation. They will be asked to check their docks when they remove them from the lake before freeze-up.
If a zebra mussel infestation has occurred, their reproduction in large numbers could be two or more years into the future. It took more than two years from their initial discovery in Mille Lacs Lake until they were found in large numbers.
Zebra mussels respond differently in every water body, and decisions on how to react to their possible presence in Green Lake will be made accordingly, said Pierce. Green Lake is Kandiyohi County’s most popular destination for water-based recreation. The Minnesota DNR also nets walleyes in the lake for eggs and milt to hatch at the New London Hatchery.
Eurasian milfoil spreads to Games Lake
Eurasian milfoil has spread from Norway Lake to the adjoining waters of Games Lake near Sunburg, the Minnesota Department of Natural Resources also announced on Monday.
The new infestation of Eurasian watermilfoil was reported on July 14 to Nick Brown, aquatic invasive species specialist with the DNR.
The plant was growing in the lake near the outlet from Norway Lake. Eurasian milfoil was initially discovered in West Norway Lake in 2000, and subsequently spread to Norway Lake.