RUTHVEN – The Iowa Department of Natural Resources (DNR) confirmed Eurasian watermilfoil is growing at four sites along the west and southwest side of Lost Island Lake, located three miles north of Ruthven in Palo Alto County.

The Iowa DNR Aquatic Plant Management team monitors 35 sites at Lost Island Lake each year. “The team spent several hours surveying the extent of the Eurasian watermilfoil, developed an emergency action plan, and treated 14.5 acres with an aquatic herbicide approved for use on lakes on July 27,” said Michael Hawkins, Iowa DNR fisheries biologist.

Eurasian watermilfoil, an invasive rooted aquatic plant native to parts of Europe and Asia, can spread quickly and outcompete beneficial native plants. It reproduces by fragmentation, which means small pieces of it grow into new plants and form thick beds.

The DNR will closely monitor Lost Island Lake this summer and fall and work with the community to develop a long-term management plan to treat the plant as needed.

Lost Island Lake is an important 1,162-acre natural lake in Palo Alto and Clay counties. The lake was removed from the State's impaired waters list in 2018 after extensive restoration efforts by the community and DNR in the early 2010s. The lake's water quality, habitat, and fish and wildlife resources have all been improving. Aggressive action to treat Eurasian watermilfoil will be important to help maintain ecological health.

“Boaters and anglers can unintentionally spread aquatic invasive species if they do not take the proper precautions - clean, drain, dry - after each time out on the water,” said Kim Bogenschutz, the DNR’s aquatic invasive species program coordinator.

• CLEAN any plants, animals or mud from the boat and equipment before you leave a water body.
• DRAIN water from all equipment (motor, live well, bilge, transom well, bait bucket) before you leave a water body.
• DRY anything that comes into contact with water (boats, trailers, equipment, boots, clothing, dogs). Before you move to another waterbody either: Spray your boat and trailer with hot, high-pressure water; or Dry your boat and equipment for at least 5 days.
• Never release plants, fish or animals into a water body unless they came out of that water body and empty unwanted bait in the trash.

It is illegal to possess or transport prohibited aquatic invasive species, such as Eurasian watermilfoil in Iowa. Boaters must also drain all water from boats and equipment before leaving a water access and must keep drain plugs removed or opened during transport.

Find more information about aquatic invasive species and a list of infested waters in the 2022 Iowa Fishing Regulations booklet or on the DNR’s website at www.iowadnr.gov/ais.

Media Contacts: Mike Hawkins, Spirit Lake Fish Hatchery at 712-336-1840 or Jason Euchner, Boone Wildlife Research Station at 515-432-2823.