The battle against giant salvinia may have met its match.
Measuring a whopping 3.5 mm long, Cyrtobagous salviniae, better known as the salvinia weevil, is taking a bite out of the invasive water plant that has plagued the waters of Lake Bistineau for more than a decade. It hasn’t been a fast process, but the Bistineau Foundation is doing whatever it takes to save their lake.
Foundation President Pete Camp said they formed the group about 2 years ago as a spinoff of the Lake Bistineau Task Force. The main difference between the two is the task force was mainly politicians, but the foundation is made up of property owners on the lake.
The invasive aquatic plant was first discovered on Lake Bistineau in February 2006, according to the Louisiana Department of Wildlife and Fisheries. Mechanical and chemical control has been utilized to try and control it, but it’s costly and requires repeat applications.
That’s why the Bistineau Foundation is focusing their attention on the weevils and it seems to be making some progress.
“Wildlife and Fisheries didn’t think they would live this far north,” Camp said. “They use them in south Louisiana all the time and they’ve had good results. They said anything north of Alexandria wouldn’t be worth trying because the cold weather would kill them.”
But Camp has other thoughts about that — if the salvinia can survive the winter months, so can the weevils.
“As long as it dies, we don’t care one way or another,” he said.
The first batch of weevils, which came from the Red River Waterway Commission, were initially tested on the north end of the lake. Camp said surprisingly they have survived the last two winters.
“Before now, that was unheard of,” he added.
Then the flood came last year and caused the lake water to rise nine feet. They were sure the weevils would get washed away and they’d be back to square one.
That’s not what happened, though.
“We went back in two or three months later and come to find out, it had just spread them out,” Camp said. “We found areas way on the other
side of the property that had weevils and across the ditch. They basically went where the water went. It really helped our project. Instead of us manually spreading them, Mother Nature did the work for us.”
So far they’ve focused efforts on the front five acres of the property, which Camp said is completely clear now and has been for a year.
“That’s another good thing about the weevils…they will keep it clear,” he said. “They keep a little bit around the edge, but the main five acre pond is clear. These are areas where Wildlife and Fisheries isn’t spraying. The only control that’s going on there is the weevils.”
It’s been a massive effort to control the salvinia. The plant has the potential to double in size every three to five days. Louisiana Department of Wildlife and Fisheries reports that the plant doubles every week to 10 days during the prime growing season on Lake Bistineau.
Fortunately, the foundation received a $10,000 donation from Aethon Energy last week that will be used to continue their efforts.
“In the past, [oil] companies have used water and not given anything back to the lake. They just take the water and use it, which is legal,” Camp said. “[Aethon] took the offense here and said they wanted to give back to the lake.”
Micah Strother with Aethon Energy said they just want to be good stewards of the community. They’ve also been really impressed with the passion and commitment of the Bistineau Foundation.
“We’re here to help and do what we can,” Strother said. “I don’t know if there’s a magic trick to get rid of it, but there are ways they can control it. We want this gift to be part of the solution.”
Camp said the donation is a win-win.
“It’s not only helping us, but it’s helping Wildlife and Fisheries too,” Camp said. “The ultimate goal is to save the lake.”
Moving forward, the plan is to continue with the weevils and mass produce them. The Bistineau Foundation utilizes a greenhouse built specifically to grow new weevils. “We’re done experimenting. We’ve seen the weevils work,” Camp said. “Salvinia is found all over the world.
Nowhere in the world is it considered under control except for where there are weevils, which is South America, India, Australia. We’re having to catch up. [The weevils] are out there killing it right now.”
Aethon Energy’s donation came at the perfect time, too.
“Despite spending almost three-quarters of a million dollars, there’s more salvinia on the lake now than there was in January,” Camp said. “When it gets out of control, you can’t spend enough money on this stuff.”
Giant salvinia has been an economic drain on the state.
“It’s in every named body of water in our state,” Camp said. “Wildlife and Fisheries is spending everything they can…that’s why private partners are so important. They can come in and really do some good for the state.”
Jack Montoucet, Louisiana Department of Wildlife and Fisheries secretary, penned a letter thanking Aethon Energy for their donation to the Bistineau Foundation. In it, he says they’ve spent nearly $800,000 battling salvinia during the past fiscal year on Lake Bistineau alone and nearly $6 million battling the invasive aquatic plant statewide.
“The control of this non-native plant has proven to be a substantial challenge to our agency and has caused untenable impacts on the users of Lake Bistineau each year,” Montoucet wrote. “You financial commitment to the foundation will undoubtably help greatly with their battle to maintain the native health of Lake Bistineau.”