Lake group hopes to use weevils to reduce milfoil

OROVILLE – The Lake Osoyoos Association will try and control Eurasian Watermilfoil through the use of weevils, rather than herbicides due to concerns from across the border about their use.

In 2011 the association, in partnership with the Okanogan County Noxious Weed Board, wrote a planning grant to the state Department of Ecology’s Aquatics Division and was awarded a grant. The goal of the grant is to develop an integrated aquatic management plan for Lake Osoyoos that leads to the management of milfoil in the lake. Upon completion of the grant the association and weed board will write a program grant which they hope will give them the funding to implement their plan for controlling milfoil on the U.S. Side of Lake Osoyoos, according to Ford Waterstrat, LOA secretary.

So far the association has obtained several “Stop Spreading Milfoil” signs and given them to the City of Oroville. These have been posted near the boat ramps at Veterans Memorial Park and Deep Bay Park. Signs were also given to Veranda Beach Resort in hopes they would help in the efforts to control the invasive weed.

The association has also published monthly newsletters to members highlighting milfoil research, water quality and current LOA news and they have also mailed Milfoil Watch Cards to all shoreline members, said Waterstrat. In addition, the group has continued bimonthly water quality testing on the lake and developed a webpage:

Representatives attended the 2011 Osoyoos, B.C. Water Science Forum and moderated a panel discussion on milfoil. Representatives also attended the Christina Lake Stewardship Society’s forum on “Exploring the Potential of Biological Control of Eurasian Milfoil in B.C.”

The association hired Aquatechnex to survey the lake for milfoil so it can document the current amount of milfoil on the lake.

The survey revealed that Lake Osoyoos has a total of 94 acres of milfoil along the shorelines, according to Waterstrat.

“Given this past winter was relatively mild the (LOA) is anxious that 2012 could be a bad year for milfoil,” said Waterstrat.

“Given the uproar by the town of Osoyoos, B.C. on the use of herbicide in front of Veranda Beach in 2011 and the overall effects of the use of herbicide, and the fact that herbicides only crate a two-year window of usefulness with milfoil, the LOA is looking at other methods including a very promising one of biological control using weevils,” he adds.

The weevils’ main food preference is milfoil and they are already native to the lake, according to the group.

“While they are only as big as a kernel of rice, they are veracious milfoil eaters,” Waterstrat said.

The south side of the lake has been impacted by the Canadians’ use of harvesters to mow down the top half of the milfoil, claims the group.

“This creates thousands of large and tiny fragments that float down to the United States side of the border and impacts our water quality and significantly helps to spread the milfoil,” Waterstrat said. “All lake front owners have seen this with large plots of milfoil washing up on their beaches.”

The group says that milfoil is here to stay and the only hope of reducing it is to control it from getting worse. Currently there are not enough funds in the Planning Grant to have an aggressive pilot program using the weevils.

“We are going to get together with our friends from the north and see if we can have a partnership to work together on a weevil pilot. It is time for action. It would be terrific if we could get our pilot in one area going this summer because then we could compare the results over time of the weevil pilot with the herbicide application that was done at Veranda Beech last September,” said Waterstrat, adding, weevils could turn out to be a more effective and less costly method of control.

Those that have questions or are interested in finding out more are invited to volunteer with the association, become a member or give a tax-deductible donation to help fight milfoil. The group’s next meeting is on Thursday, April 26 at 6:30 p.m. at Trino’s Mexican Restaurant in Oroville.