The Minnesota Department of Natural Resources has confirmed that zebra mussels have been found in Bde Maka Ska.
The spread of the invasive species follows a report last September that zebra mussels were found in Lake Harriet, just downstream of Bde Maka Ska.
The Minneapolis Park and Recreation Board watercraft inspector contacted DNR after finding two juvenile zebra mussels on a sailboat that was being removed from the lake. The Park Board hasn’t found any additional mussels but inspectors will review all sailboats being removed from Bde Maka Ska.
The Park Board plans to assess the zebra mussel population in the lake in partnership with the DNR, Minnehaha Creek Watershed District and Blue Water Science and Waterfront Restoration. Park staff are using eDNA sampling, a process of testing filtered water for signs of the mussels.
The board says treatment of the mussels won’t likely be effective. The mussels that inspectors found were the result of reproduction inside the lake, as opposed to bring brought in. Furthering that point is the fact that the boat they were found on had been moored in the lake for quite a while.
State law requires boaters to clean their vessels of aquatic plants and prohibited invasive species, drain water by removing drain plugs and keep them out during transport and dispose of unwanted bait. The DNR recommends boaters spray their boats with high-pressure water, rinse with hot water and let them dry for at least five days before moving to another body of water.
An invasive species like zebra mussels competes with native species for food and habitat, and can cause significant damage to water intake pipes. The sharp, wedged-shaped molluscs can also be dangerous for swimmers. Zebra mussels do more than $1 billion in economic harm in North America each year, according to the Minnesota Aquatic Invasive Species Research Center.
As of May, the DNR has listed 335 waterbodies across the state as being infested due to a confirmed zebra mussel population or a connection to an infested waterbody. As of Oct. 1, the DNR had not added Bde Maka Ska to the list.