Idaho Officials Find Aquatic Herbicides a Success

Published April 1, 2008

Encouraged by two years of success in fighting back noxious, invasive plant species with aquatic herbicides, the Idaho Department of Agriculture has asked state legislators to expand a program to eradicate Eurasian milfoil.

Destructive Weed

Under legislation signed into law in April 2006, the state’s Department of Agriculture has been encouraging and providing financial support for local communities to apply aquatic herbicides as a safe and effective means of eradicating Eurasian milfoil.

The plant is a serious pest, taking root in the bottom of lakes and ponds and sending long, entangling tendrils to the surface. The aggressive, invasive weed quickly forms very dense, thick mats of vegetation at or just below the water’s surface.

The weeds interfere with water-based recreation such as fishing, boating, water skiing, and swimming, and they can create a stench that makes walking along shorelines next to impossible. Swimmers unaware of the danger of submerged milfoil have been known to become entangled in the weeds and drown.

Milfoil also causes other environmental problems. The dense mats of weeds increase the pH of the water and reduce the amount of oxygen available for fish and other aquatic life. In addition to asphyxiating fish and other water life, milfoil creates an ideal breeding ground for mosquitoes.

Aquatic Herbicide Success

The Idaho Department of Agriculture and local communities throughout the state report tremendous success since the large-scale use of aquatic herbicides in 2006.

Assertions by environmental activists that aquatic herbicides would harm the environment have been proven false, as the herbicides have efficiently eradicated targeted noxious weeds while being environmentally safe in all regards.

Brad Bluemer, the noxious weed superintendent of Bonner County, believes the resounding success of aquatic herbicide treatments over the past two years will mute many of the protests by environmental activists.

“I’m not expecting it to be so serious this time,” Bluemer told the January 18 Bonner County Daily Bee.

County Finalizes Plans

Based on the real-world results achieved by aquatic herbicides in Bonner County, the county’s Aquatic Invasive Species Task Force on January 24 finalized plans to apply the herbicides to 38 acres of Priest Lake this year. The Aquatic Invasive Species Task Force reached a final battle plan by drawing from the best recommendations of state- and county-level experts on noxious weeds.

In 2006 Bonner County successfully used a chemical known as 2,4-D to eradicate Eurasian milfoil in many of its lakes and ponds. Other chemicals, endothall and Renovate, also have been successful in attacking the milfoil.

The Idaho Department of Agriculture has been especially supportive of 2,4-D because of its low cost and high effectiveness.


James M. Taylor ([email protected]) is a senior fellow of The Heartland Institute and managing editor of Environment & Climate News.