Invasive lake weed confirmed in Chub Lake in Carlton County

Eurasian watermilfoil, a foreign plant that is spreading across Minnesota lakes, has been confirmed in Chub Lake in Carlton County.

The plant first was reported in the lake just outside Carlton in early September by Minnesota Department of Natural Resources fisheries staff. A recent follow-up survey found several stands of milfoil in the lake.

It's the first lake in Carlton County to see an infestation of the invasive plant, which so far has spared most of Northeastern Minnesota.

Milfoil can grow in mats so thick that boating, swimming and even fishing can become difficult, if not impossible. The plant's big leaves form a floating canopy that can crowd out native plants, DNR officials say.

It's also very prolific: A single fragment of stem or leaves can take root and form a new colony. And it's likely that the weed is spreading by fragments clinging to boats and trailers moved from lake to lake.

DNR officials say the plant can be thinned in places to allow boat traffic, but it has never been entirely removed from a lake once it takes hold.

"The DNR has more than 20 years experience with attempts to eradicate Eurasian watermilfoil from Minnesota lakes," Chip Welling, Aquatic Invasive Species Management coordinator for the DNR, said in a statement. "We also have learned a lot from watching efforts in other states. The plant can be managed, but complete eradication is not a realistic goal."

The focus now will be trying to prevent the plant from spreading to other Northland lakes. The DNR will now:

# Designate Chub Lake as an infested water, which prohibits the transport of water and limits bait harvest.

# Add new signs at the public water access on Chub Lake to indicate the presence of milfoil.

# Start watercraft inspections and enforcement efforts around the lake to help prevent the spread of milfoil.

# Work with the lake association and lake residents on possible management of the plant.

Boaters are urged to remove aquatic plants from their boats, trailers, nets, anchors and other equipment before trailering their boat to another lake or river. It is unlawful in Minnesota to transport water or aquatic plants from infested waters.

Eurasian watermilfoil first was discovered in Minnesota in 1987 and has since been spread by people to 224 lakes and eight rivers. It has been found in the Pit Lake in Gilbert and Horse Shoe Lake in St. Louis County; Sturgeon Lake in Pine County; and Ice, McKinney and North Twin lakes in Itasca County.