Sherburne and Stearns counties saw 10 lakes and rivers added to the Department of Natural Resources’ list of infested waters in 2020 and 2021.
The aquatic invasive species found in these bodies of water were zebra mussels (seven bodies of water), Eurasian watermilfoil (three bodies of water), and multiple sclerosis (one lake). The two lakes listed as infested in 2021 were both connected to another infested lake. One lake, Lake Orono in Sherburne County, was recently listed for two aquatic invasive species.
Here’s a breakdown of the area’s water bodies and the aquatic invasive species that have been found there:
- Big Lake in Big Lake, listed in 2020 for zebra mussels
- Big Elk Lake in Palmer Township, listed in 2020 for Eurasian Watermilfoil
- Birch Lake in Big Lake Township, listed in 2020 for Eurasian Watermilfoil
- Lake Orono at Elk River, listed in 2020 for Zebra Mussels and Eurasian Watermilfoil
- Elk River downstream from Lake Orono to the Mississippi River at Elk River, listed in 2020 for zebra mussels (related to Lake Orono)
- Mitchell Lake in Big Lake, listed in 2020 for zebra mussels
- Blacks Lake near Big Lake, listed in 2021 for zebra mussels (connected to Big Lake)
- Lac Beaudry in Big Lake, registered in 2021 for zebra mussels (connected to Big Lake)
Benton County had no newly listed water bodies in 2020 and 2021.
All invasive species are a concern
There isn’t one specific species that MNR is more concerned about than others, said Heidi Wolf, MNR’s invasive species program supervisor; the DNR cares about them all.
The MNR continues to learn more and more, however, is multiple sclerosis, an invasive aquatic plant first found in Minnesota in 2015 in Stearns County’s Lake Koronis and connected Mud Lake.
Related:Kimball region lake confirmed as hotbed of invasive algae
Wolf said the DNR was curious how the species would interact with native plants in Minnesota. She said it was a mixed bag.
“In some cases (multiple sclerosis) has remained very localized in small populations and continues to be managed in local water bodies,” she said.
However, Lake Koronis has a large population. Wolf said MNR is working with researchers on how to effectively deal with invasive species.
Wolf said there was no specific species that spread the fastest. Much of this spread is based on the behavior of boaters or swimmers – whether people clean their docks and elevators before moving them, or make sure their boats are cleared of plants before taking them to a new lake. .
“A lot of it is based on people’s personal responsibility and whether they take it seriously,” Wolf said.
MNR has data on zebra mussel infestations; As of early July 2021, 3.5% of lakes in Minnesota were infested with zebra mussels. As of October 2019, 8% of lakes in Minnesota were on the infested water list.
Related: Zebra mussels found in Big Watab Lake
What can I do to prevent the spread of invasive species?
Part of the spread has to do with the connections between bodies of water. When the upstream water body becomes infested, it is likely that the infestation will naturally spread to the downstream water body, Wolf said.
But for terrestrial water bodies, “for the most part, yes, they’re carried by humans,” she said. “It’s obviously clear when it expands overland that that’s what’s going on there.”
The common mantra is “clean, drain, dispose”: ask boaters to clean and empty their boats and throw bait in the trash.
Wolf stated that washing your boat at high pressure and high temperature works well. She recommended drying your boat for at least five days between lakes (the longer the better).
She also encourages Minnesotans to remember their responsibility for platforms, elevators and rafts. By law, all of these must be out of the water for 21 days before being moved to another body of water. These structures pose a high risk of invasive species attached, Wolf said.
Boaters can also exercise their power as consumers, Wolf said. That could mean telling dealers and manufacturers that easy-to-drain personal watercraft are what you’re looking for.
“(You can) push the industry to make sure they’re accountable – that they’re not making a product where it’s really, really hard to dump,” she said.
For more details on what to do regarding the different types of equipment related to water recreation, visit dnr.state.mn.us/invasives/preventspread.html.
The MNR updated its list of infested waters on July 23.
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