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County works to stop spread of invasive aquatics

Boaters should pay attention to the invasive aquatics signs posted near the boat landing. This sign at Chub Lake lets the boater know which species is in the lake and lists how to prevent the spread into other lakes. Photo contributed by Karola Dalen1 / 2
Level 1 Watercraft Inspector Elizabeth Alexson holds a sample of Eurasian Water Milfoil, an aquatic invasive species, at the Chub Lake public boat landing. Photo contributed by Karola Dalen2 / 2

The good news is that Carlton’s Chub Lake is a fairly clean lake for the size.

The Chub Lake association and Carlton County have been testing the water quality of Chub Lake after the discovery of Eurasian watermilfoil, an aquatic invader.

Aquatic invaders are not native to Minnesota and cause economic and environmental harm. Some of the invaders threatening this region include Eurasian watermilfoil, zebra mussels, and spiny water fleas. Eurasian watermilfoil in particular impairs recreational use — including fishing, boating and swimming — decreases property values and harms lake ecosystems by creating dense mats of vegetation.

The Eurasian watermilfoil is a relative to the native Northern watermilfoil, but can spread fast and crowd out the native plants and upset the natural ecosystem. Once it has established itself in a lake, the only recourse is to treat the lake with a chemical, which only targets the invader, but is safe for most of the native plants and fish.

Carlton County Zoning and Environmental Services is using state funds from the Aquatic Invasive Species (AIS) Prevention Aid Program to prevent or limit the spread of aquatic invaders within the county.

Eurasian watermilfoil is the only documented invader in Carlton County and was found in Chub Lake about six years ago and in Bear Lake last year. Because of this, the county is in an excellent position to prevent the further spread of aquatic invaders to our lakes.

An important note is to pay attention to other lakes to prevent inadvertently introducing a new invasive species to our local lakes. Both Lake Mille Lacs and Lake Minnetonka have been invaded by the tiny but persistent  zebra mussels for many years.

The water milfoil invasion probably began thanks to a careless boater, said Heather Cunningham, Carlton County Zoning and Environmental Services Administrator.

“It only takes a small piece, like half a leaflet,” Cunningham said, about the small plant that used to be commonly used in aquariums.

She compares it to trying to rid a yard of dandelions. Even if the yard is treated one summer, it still requires maintenance to keep it in check or the yard will turn a bright, sunny yellow in the following years.

Some states have had success utilizing the native weevil to stop the Eurasion milfoil from spreading so quickly.

The old saying, an ounce of prevention is worth a pound of cure rings true for this little water invader.

Inspections are one of the most cost-effective methods of controlling aquatic invaders through prevention. Inspectors are located at the county’s busiest boat landings this summer

The county has hired six Level 1 Watercraft Inspectors trained by the Department of Natural Resources (DNR). Their purpose is to educate the public about the impacts of aquatic invaders and ensure boaters are in compliance with DNR regulations. To do this they make sure all water is drained and all plants are removed from boats and trailers before entering or exiting a lake.

Boat owners should also drain water from motors, live wells and bait containers as well as disposing of unwanted live bait on land.

Use hot water (104 F) to rinse the boat and trailer and dry them for a minimum of five days.

Other water toys, such as skiss, inner tubes, etc, should also be inspected for little invasive hitchhikers.

Happily, once a plant has been dried out, it cannot reproduce and its life cycle has been permanently ended.

Additionally, local law enforcement has received training on AIS laws and will increase patrols at boat landings. To promote education beyond boat landings the county is working with CLIMB Theater, an educational theater company, to develop and present AIS curriculum to local schools. CLIMB will deliver in-classroom presentations to Carlton County students in kindergarten through sixth grade. Students learn what AIS is, its impacts on people and the environment, and how to prevent the spread of AIS. With these combined efforts, the county hopes to halt the spread of AIS and preserve the integrity of Minnesota water for years to come.

Paying for prevention

In 2014 the state legislature established a $10 million dollar annual Aquatic Invasive Species (AIS) Prevention Aid Program to provide opportunities for counties to better manage aquatic invaders. Carlton County received $33,426 in 2014 and $74,279 in 2015 from this fund to develop a program focusing on four initiatives: boat inspections, education and outreach, enforcement, and treatment. It is anticipated that more funding will be received for implementation of the program in 2016 and 2017.