Despite the raging battle against giant salvinia on Lake Bistineau, Bistineau Task Force Member Pete Camp says their weevil project is succeeding.
During the Bistineau Task Force meeting Thursday, he updated members on the progress of the weevils in the gravel pit area at the north end of the lake.
“The gravel pit area is not connected to the lake,” he said. “There was a lot of success in this 20-acre area. We were able to clear maybe a third to a half of that acreage last summer. We checked weevils all the way up through October and November and we still had weevils.”
Camp says weevils survived through the winter, noting it was a mild winter.
“We’ve never checked that area where we didn’t find weevils up there,” he said. “After the flooding, we checked the area and we found weevils.”
More samples were taken as late as Saturday, May 21, and there were weevils, larvae and eggs in that area, Camp said.
They’ve also restocked the greenhouses with weevils from the gravel pit area, he said.
They will also be moving weevils from a pond 20 yards away to the lake once they are established.
A new 30×80 greenhouse will soon be under construction, and they are pleased with the progress, he said.
Jeff Sibley, a biologist and manger for Louisiana Department of Wildlife and Fisheries Region 1, says while he applauds the success of the BTF’s weevil project, right now the combination of weevils and spraying aren’t working to control the salvinia as quickly as they’d like.
He spent a large portion of time answering questions regarding the lake, giant salvinia and drawdowns. He says for the drawdowns, there are many different factors to consider, one being that between March and roughly July 15 is the peak boating season, as well as the peak season for businesses around the lake. The best time to conduct a drawdown is in July and August, the two driest months of the year, he said, adding that if they can get at least 30 days of drying action, then the drawdown would be considered a success.
Not only does it dry out the salvinia, but it also helps in drying out other aquatic plants that hinder the health of the lake, he said.
“I would estimate, based on past trends, that we’ll be looking at a drawdown,” he said.
The salvinia is growing at an exponential rate this year, he says, mainly due to the nutrient-rich water that came from the March flooding. He says they’ve already sprayed about 600 acres this year.
“It’s a lake-wide problem, it’s a region-wide, it’s a statewide problem,” he said. “You could eradicate every piece of it in Lake Bistineau, completely get rid of it, but you’re one boat launch away from having the same problem again. When there is a current going, a lot of it tends to go the quiet, still waters on the side. That coming out of the pits is only a small portion of what’s in the lake.”
He reiterated much of what he said during a public meeting Thursday, May 20, in explaining how they are fighting the salvinia, and the research that continues in finding a solution.
The management plan is targeting keeping recreation open on the lake, while combatting the aging process of the lake and giant salvinia.
The next meeting is scheduled for July 28 with a meeting place and time to be determined.