Milfoil counterattack
Idaho has begun a $4 million campaign to pluck, poison and smother a pernicious weed that has invaded state lakes and rivers.
In less than eight years, Eurasian milfoil has managed to choke nearly 7,000 acres of lake and river bottom in the state, much of it in the Panhandle. By the end of summer, officials hope Idaho will be one of the few places in the nation to have turned back the invasion.
“We have a rare opportunity to rid ourselves of this problem,” said Eric Anderson, a Republican state legislator from Priest Lake who led the crusade to fund the massive milfoil control effort.
Anderson, who earned the nickname “Morty Milfoil” in the Legislature, believes the weed threatens the very health of North Idaho’s economy, as well as the natural environment. The feathery weed grows in thick mats. It not only crowds out native species, but can smash fast-moving boat hulls and entangle swimmers.
“Our water is our economy here. Our water is a precious commodity,” Anderson said. “If this weed was on land and you were to drive down Interstate 90 and see a 100-acre bloom that’s 30 feet tall, you’d be saying ‘Oh my God!’ It’s just absolutely imperative that we get a handle on it quickly.”
Until this summer, Idaho’s approach was to focus on a few hundred infested acres each season, as money became available, Anderson said. Milfoil, however, grew much faster than budgets.
The weed also infests many waterways in Washington, including Eloika and Liberty lakes in Spokane County, but the two states’ approaches to fighting the plant are now as different as apples and potatoes. Washington authorities use some of the very same methods to fight milfoil, but on a far smaller scale. Nearly $2 million in state funds will be spent this year alone in Idaho’s Kootenai and Bonner counties. In all of Eastern Washington, a total of about $120,000 is being devoted to milfoil control projects, said Jani Gilbert, Department of Ecology spokeswoman.
Herbicides are the main weapon being deployed against milfoil in Idaho. Roughly 100 tons of herbicide are scheduled to be dropped into Bonner County waterways, according to Steve Holt, a Sagle resident and spokesman for Citizens for Sustainable Solutions. The group is concerned the chemicals could endanger swimmers, fish and wildlife. It’s calling on county officials to consider other control methods, such as scuba divers and a species of tiny insect that slows milfoil growth.
“We don’t want to be dumping an endless cycle of potentially toxic chemicals in our watershed if we don’t have to,” Holt said.
The issue has become contentious enough in recent weeks to prompt an anti-chemical march in downtown Sandpoint, Holt said. The group is especially concerned by one of the main herbicide treatments, a product known as 2,4-D, a component of the Agent Orange defoliant used in the Vietnam War.
The chemical is one of the most commonly used herbicides in the nation, according to the Web site of the U.S. Environmental Protection Agency, used by millions to battle dandelions.
The EPA says there is no evidence linking the chemical to cancer. A dioxin in Agent Orange, not 2,4-D, was linked to high rates of cancer in Vietnam veterans. But other states, including California and New Jersey, have noted increases in non-Hodgkin’s lymphoma in farmers exposed to 2,4-D. The compound breaks down fairly quickly and is nearly undetectable after two months of application to lakes, according to a fact sheet from Cornell University.
Officials in Kootenai and Bonner counties insist the herbicides pose no risk to swimmers or anglers, though some carry short-term warnings against being used near drinking water or irrigation sources.
Holt worries about what isn’t known. “How many times have the EPA or federal Food and Drug Administration said something was OK for you to do, only to pull it off the market three years later?”
Holt wants the county to purchase a species of native weevil that has shown to be effective in controlling milfoil in other states, including Minnesota and Vermont. Last week, the president of an Ohio-based company that grows and sells the sesame seed-sized weevils visited Sandpoint.
“The only long-term solution has been the weevil,” Holt said.
But the weevils can take two or three years to make a dent in milfoil, said Mark Schwarzlaender, assistant professor and biological weed control expert from the University of Idaho. Schwarzlaender supports the idea of trying the insect, but said herbicides will be more effective in the short term.
The weevils are found in several lakes and rivers in Eastern Washington, but not at concentrations high enough to significantly reduce milfoil, according to research by the Washington Department of Ecology.
Washington first used herbicides at Stevens County’s Loon Lake in 1998, when state Sen. Bob Morton added a line to the Ecology Department’s supplemental budget requiring the agency to issue a permit. Ecology previously had balked at such requests, saying too little was known about the effects of putting 2,4-D in lakes.
Herbicides are being used in Idaho because a dramatic reduction is needed to reduce milfoil to manageable levels, said Leslie Marshall with the Bonner County public works department. The county is home to about 3,800 acres of milfoil – roughly half of all the weed in Idaho. The first herbicide treatments in the county will begin July 10.
Hopefully, the herbicides will help kill about 85 percent of the weed, Marshall said. That would make it easier to control the weeds in subsequent summers using scuba divers or even sun-blocking plastic mats.
“Our best and fastest and most successful way was with herbicides,” Marshall said. “We’ll never, ever eradicate the milfoil from our waterways, but we’d like to get it manageable.”
The Idaho Conservation League recently sent a letter to Bonner County commissioners urging against such widespread use of chemicals. Apart from human health concerns, the group says the herbicides could harm threatened bull trout in Lake Pend Oreille. A copy of the letter was sent to the U.S. Fish and Wildlife Service, which had not previously been notified.
Because federal dollars are not being used to fund the project and few acres of federal land are involved, the Fish and Wildlife Service does not have a formal role in the project, said agency spokesman Tom Buckley. Bull trout will not likely be in the herbicide application area – they prefer deeper, colder water this time of year. But if the herbicides kill fish, the county could be in violation of federal law.
“If bull trout do die, the county’s not protected under the Endangered Species Act,” Buckley said.
Buckley stressed that the Fish and Wildlife Service supports combating milfoil, but there are questions about the effects of herbicides on aquatic life.
David Lamb, the Coeur d’Alene Tribe’s lake ecologist, said herbicides are the only practical way of turning back the milfoil tide. The tribe is also using scuba divers near swimming areas and in places where the infestation is not yet thick, but herbicides will be used on about 300 acres at the southern end of Lake Coeur d’Alene. The tribe received about $200,000 from the state to fight milfoil.
“We’ll hit it with everything we can to keep it in check,” said Lamb, also chairman of the state’s milfoil task force. The tribe worries the weed is not only crowding out fish and native plants, but the thick, floating mats could also be harming eagles and osprey, Lamb said. It’s likely the weeds make it tougher for the raptors to catch fish.
Milfoil is not yet growing near Coeur d’Alene, but it’s just a matter of time, Lamb said. Weed fragments as small as an eyelash can drift through the lake and take root. Jet boats and personal watercraft can also suck weed fragments into their motor compartments, only to spew out the plants later.
Last week, about 300 acres in Hayden Lake were treated with three forms of herbicide, thanks to a $306,000 grant from the state’s milfoil eradication fund, said Nina Eckberg, Kootenai County weed superintendent. By Thursday, milfoil was showing signs of dying in the Sportsman’s Park area of Hayden Lake’s north arm, Eckberg said. Another 125 acres will be plucked by divers, including the area near Honeysuckle Beach. Before this year, the county had enough money to treat only about 85 to 100 total acres.
Eradication projects are scheduled for both Spirit and Cocolalla lakes. Hauser Lake doesn’t have milfoil yet, but the state is paying for a wash station to help boaters ensure hulls and trailers are free of any weed fragments. Another wash station is planned for Priest Lake, which also remains weed free for the moment.
With any luck, Idaho has a chance to turn back the invasion, Eckberg said. “This is a chance for us to really knock it back hard.”