The Minnesota Department of Natural Resources announced last week that six juvenile zebra mussels had been found in Bone Lake in Scandia, near the lake’s public access. The discovery was made in late May.
Zebra mussels are an invasive species with no local natural predator. They cling to solid surfaces underwater, and their sharp edges can pierce the skin of unfortunate swimmers. They can also clog pipes and other underwater equipment. They filter the water, which means that most lakes with mussels tend to be on the clearer side, but that increased water clarity can also result in increased aquatic weed growth.
The DNR sent out a press release announcing the discovery of the mussels on June 6. At publishing time, the department had not yet responded to The Times’ attempts to reach a representative for further comment; Scandia Mayor Christine Maefsky told The Times that to her knowledge, the DNR has not reached out to the city, either. However, Mike Kinney, administrator of the Comfort Lake-Forest Lake Watershed District, shed more light on the discovery and what it could mean for the lake going forward.
Kinney said the district was notified of the findings on May 28. The good news about the finding is that all of the mussels were juveniles and not yet capable of reproducing. If adult mussels are found in a lake, the safe assumption is that the body of water in which they’re found is already infested by thousands of mussel offspring.
“The ability to contain and treat [in that scenario] would be quite infeasible,” Kinney explained.
If only juvenile mussels are found in one section of a lake, however, it’s possible that the lake could be treated in order to kill off any remaining juveniles before they propagate. Kinney said members of the DNR are meeting tomorrow, June 10 to discuss what should be done about Bone Lake. He said the DNR could elect to quarantine the area where the mussels were found and treat it with copper sulfate, installing a floating curtain that would keep the chemical and the treated water separate from the rest of the lake until the treatment is done. The problem is that even if the DNR decides to do the treatment and ends up killing all the mussels, enough boats from infested lakes make it into Bone Lake that the encroachment of invasive species is more a matter of when, not if.
“The statistics work against you, unfortunately,” Kinney said.
Regardless of the outcome, Kinney said the discovery is an important reminder for boaters transferring from one lake to another to thoroughly clean their watercraft, drain it of all water and dump old, unwanted bait rather than using it in a new lake.
“When you look at invasive species that are in the east coast … there are others on the horizon that are much worse that could end up here,” he said.