The Minneapolis Park and Recreation Board continues to take extra precautions with regard to aquatic invasive species at Lake Harriet, after volunteers found a single zebra mussel there this past September.
The board has dedicated an aquatic planter harvester exclusively to the lake and has updated its procedures for deploying sampling equipment, said Deb Pilger, director of environmental management. It’s also continued to inspect all boats coming to and leaving its launches and check the lakes for the mussels every couple of weeks.
The efforts come about eight months after the finding of the single zebra mussel on a boat cover in the lake. The Park Board, the Minnesota Department of Natural Resources and contractors conducted 67 hours of searches after the finding, but did not find any other mussels.
“The fact that we haven’t found any more doesn’t mean there isn’t a population,” Pilger said.
Zebra mussels, which hitchhiked to North America from the Black Sea in Europe, can significantly impact the ecology of a body of water. The mussels can coat the bottoms of lakes, crowd out other mussel species and decrease phytoplankton populations, changing the water quality of lakes.
About 1.8 percent of lakes in Minnesota are listed as infested with zebra mussels, according to the state DNR, including Lake Minnetonka, Lake Hiawatha and Lake Nokomis. Minnehaha Creek is also infested.
Pilger said that the Park Board has already had four zebra mussel violations occur on launches this year, three of which occurred at Nokomis and another at Bde Maka Ska. Inspectors turn away boats found to have zebra mussels on them and require that the boat owners clean their equipment.
Boaters must clean visible aquatic plants, zebra mussels and other prohibited species from watercraft, trailers and equipment before transporting from any water access. They also must drain water from bilge, live well, motor, ballast tanks and portable bait containers before leaving water accesses or shoreline property.
Boaters must also keep the drain plug out and water-draining devices open while transporting boats. In addition, fishermen are not allowed to dump live bait into state waters, on shore or on the ground.
Pilger noted that the Park Board is also working to prevent the spread of other aquatic invasive species, such as hydrilla and starry stonewort. Visit goo.gl/g1WBGY to learn more about the board’s efforts to prevent the spread of invasive species.