Killing Zebra Mussels With Environmentally Safe Bacteria
MINNEAPOLIS (WCCO) — With a snorkel and pair of flippers, a diver scours the bottom of Lake Nokomis in Minneapolis. But this isn’t about having fun. Dr. Dan Malloy is on a fact-finding dive.
At the request of the Lake Minnetonka Watershed District, Malloy is looking for any hard evidence showing the spread of zebra mussels. The aquatic invasive species (AIS) already infests Lake Minnetonka and there’s reason to believe the outflow from Minnehaha Creek is also spreading the mussels into city lakes downstream.
During his short exploratory dive, Malloy found no mussels clinging to rocks at the bottom of Nokomis. Sadly, that’s not the case on Lake Minnetonka, where razor-sharp shells make shorelines hard to walk on. The tiny zebra mussels cling like barnacles to rocks, boats, docks and water pipes.
“I’m a tree hugger and I’ve worked for years to try to find ways to reduce the risk of pesticides,” Malloy said.
He’s been researching zebra mussels since they were first discovered in the St. Lawrence Seaway in New York back in 1989. Four years after his research began, he and his colleagues discovered what may well be the magic bullet. It’s a simple soil bacterium known as “Pseudomonas Fluorescens.”
“Zebra mussels eat it, eat the dead cells and they die because their digestive system is disrupted,” explained Malloy.
It works much like the natural bacterium BTI works on killing mosquitoes and black flies — safe and effective.
Malloy said bacteria are just as effective when they are dead, a benefit that adds to the safety. Any treatment for zebra mussels must not harm beneficial aquatic life like insects, fish and plants.
Lois Sinn Lindquist is Executive Director of the non-profit Minnesota Waters, a group that is dedicated to the protection and stewardship of Minnesota’s water resources.
“The hope could be that there is an application that is been proven that it’s not toxic, it’s safe. It won’t hurt the fishery, won’t hurt the plants,” said Lindquist.
Further testing by the Environmental Protection Agency will be needed before the product can be brought to the market.
While it’s probably too early to call it a breakthrough, the bacterium may well be the most promising news in the zebra mussel battle.
“We grew it up, we tested it and its safety is extraordinary how effective it is in killing zebra mussels and quagga mussels,” Malloy said.