Local lakes and lakegoers are under attack — from non-native aquatic invasive species. Once infested with species such as zebra mussels or Eurasian watermilfoil, it’s difficult or even impossible to eradicate the threat to the lake.
"By the time it's identified it's too late," said McLeod County director of environmental services Marc Telecky.
According to a 2019 infested waters list published by the Minnesota Department of Natural Resources, two McLeod County lakes — Belle and Cedar lakes — are listed as infested with Eurasian watermilfoil, an invasive plant that can grow up to 20 feet, creating a canopy and dense mats at the water’s surface that inhibits water enthusiasts. It can also overtake habitat and native aquatic plants, possibly lowering diversity.
Zebra mussels attach to hard surfaces under water and can encrust equipment such as boat motors and hulls. Swimmers and pets can cut their feet on zebra mussels attached to rocks, docks, swim rafts and ladders among other environmental and habitat threats.
In Meeker County, nine lakes are listed as infested:
- Clear Lake, Eurasian watermilfoil
- Erie Lake, Eurasian watermilfoil
- Little Mud Lake, Eurasian watermilfoil
- Manuella Lake, Eurasian watermilfoil
- Lake Minnie Belle, Eurasian watermilfoil
- Lake Ripley, Eurasian watermilfoil
- Lake Stella, zebra mussels and Eurasian watermilfoil
- Lake Washington, zebra mussels and Eurasian watermilfoil
- Wolf Lake, Eurasian watermilfoil
The good news is steps are being taken to stop the spread of AIS. Meeker County has been aggressive in its response, including the hiring in June of Ariana Richardson, the county’s new AIS coordinator.
Meeker County lake property owners, lake associations, local units of government, DNR technical assistance and DNR financial assistance work together in controlling the spread of AIS, according to Wendy Crowell, AIS management consultant for DNR.
One of the biggest ways AIS spread to other lakes is by hitching rides on watercraft and equipment anglers, boaters and others use. So inspection has been a major component in the war on AIS.
“Part of the effectiveness and us managing the spread has been the inspection program,” Richardson said. “We have a very thorough inspection program and a group of inspectors. The goal with most counties is to really help facilitate the management of public waters, so through the AIS program … my role is … somebody that can help facilitate the grant process and oversee the management and lake profiles.”
The same can be said in McLeod County, albeit on a smaller scale. Telecky says the department is in contact with local lake associations but does not conduct inspections such as Meeker County. McLeod County does receive funds from the state, which are distributed to local associations to educate property owners.
"The money's available for lake associations to contact us, and if they have a program they can apply for a grant," Telecky said. "To take that a step further, we are in the process this fall and winter of looking at the process more in depth. We'll see if there's more that we can do."
The other way AIS spreads is via water movement from one waterbody to another during their free-floating, tiny life stage, according to Crowell. Telecky agreed.
"I think, personally, that a lot of the transfer has to do with water flow more so than a trailer at a boat launch," he said.
Starry stonewort, bushy and bright green macro-algae with a star-shaped bulbil, is another invasive species that is a concern for local lakes. It recently appeared in Lake Koronis, which poses a threat to central Minnesota lakes due to its proximity.
“Educating boaters in proper decontamination of their boats is the main way to reduce the risk of AIS," said Kristin Jaquith, a member of the Lake Minnie Belle Improvement Association. "Starry stonewort, for instance, can be spread by just one tiny section of the weed entering the lake.”
Along with making waters less appealing for recreation, AIS can also be a detriment to fisheries and lake ecology.
“Our native fisheries … our fishing population in the lakes, the fish that people eat and do for sports, they’re at risk," Richardson said. "Serious risk, at the point that there’s AIS in a lake. So you’re looking at decreased numbers, decreased health … I would say, you would see that mostly impacted by zebra mussels. They really mess with the water column and all of the (foundations) of that food chain, and so you’ll see the cascading effects with time and as the population grows.”
Currently there are no lakes in McLeod County that are infested with zebra mussels, but Telecky reiterated that once they're discovered, it's too late.
Minnesota law requires anglers and boaters to clean visible aquatic plants, mud and debris off their boats, trailers and other water-related equipment before leaving a water access or shoreland property. They also must drain water-related equipment, boats, ballast tanks, portable bait containers, motors, and drain bilges, livewells and baitwells by removing drain plugs before leaving water access. Lastly, they must dispose of unwanted bait such as minnows, leeches, worms and fish parts in the trash.
Some invasive species are small and difficult to see. To remove or kill them, it is recommended to spray boats and other water craft with high-pressure water, rinse with hot water of about 120 degrees for at least two minutes or 140 degrees for at least 10 seconds, and dry for at least five days before moving to another water body.