Zebra mussels pillage lakes and rivers, devouring small organisms and algae through their efficient filtering systems. They are able to affix themselves almost like glue to objects, clogging pipes and creating swimming hazards. The Douglas County Lakes Association invited Dr. Daniel Molloy, a retired scientist from the New York Museum Cambridge Research Institute, to visit Alexandria area lakes and discuss a possible solution to the zebra mussel proliferation – a biopesticide called Zequanox.
By: Wendy Wilson, Alexandria Echo Press
Zebra mussels pillage lakes and rivers, devouring small organisms and algae through their efficient filtering systems. They are able to affix themselves almost like glue to objects, clogging pipes and creating swimming hazards.
The Douglas County Lakes Association invited Dr. Daniel Molloy, a retired scientist from the New York Museum Cambridge Research Institute, to visit Alexandria area lakes and discuss a possible solution to the zebra mussel proliferation – a biopesticide called Zequanox.
Molloy and a colleague discovered the bacterial strain pseudomonas fluorescens was able to kill the mussels. Pseudomonas fluorescens is the active ingredient in Zequanox.
Molloy has studied zebra mussels for more than 20 years. He became involved in researching the mussels in 1991 when companies were using bleach to combat the mussels in clogged pipes.HIGH HOPES
“We have taken the stance that doing nothing is not acceptable,” said Bonnie Huettl, Douglas County Lakes Association president.
The bacteria used in Zequanox are common and can be found inside refrigerators or on rugs, according to Molloy.
“It is omnipresent everywhere,” he said. “It is already in the lakes and that is because it lives in soil, and its job is to protect plants roots.”
The scientists at the research institute discovered zebra mussels died after consuming the bacteria, according to Molloy.
“It was serendipity, luck, persistence,” he said of the discovery. “We fed it to zebra mussels and quagga mussels, their cousins that cause problems, and it kills them.”
Marrone Bio Innovations is the commercial developer of Zequanox. In collaboration with the Douglas County Citizens’ Committee on Zebra Mussels (DCCC) and the Douglas County Lakes Association, Marrone provided a research request to the Minnesota DNR June 1 to evaluate the use of Zequanox in local lakes. The application has been delayed due to the Minnesota government shutdown, according to Huettl.
Marrone Bio seeks to test Zequanox in Lakes Carlos, Darling and L’Homme Dieu.
“This whole thing is very pioneering,” Molloy said.
THE TESTING PROCESS
Small scale testing using Zequanox in power plants has been conducted with larger-scale trials starting this summer, according to Molloy.
“So this cutting edge is part of why we were getting involved in it,” Huettl said. “We should go forward with it while we have the chance.”
Testing would begin with jar assays in a laboratory-type setting using a cloud of Zequanox and then graduate to the implementation of larger aquaria. Eventually, they would isolate a pile of rocks in a lake, to see if Zequanox kills the mussels.
“I call it baby-steps of research,” Molloy said.
Molloy and Dick Osgood, a certified lake manager, discussed the application of Zequanox.
“One of the challenges to open water is how do you apply it if the zebra mussels are on these rocks,” Molloy said. “Research has to be done to find a very efficient, cost effective and efficacious delivery system to get a little cloud down there for… like six hours.”
A granular blanket of Zequanox could be employed, according to Molloy. A delivery system that would allow the Zequanox to stick to the articles covered with the mussels also might be a possible solution, Osgood suggested.
The DCCC anticipates approval of the proposal from the DNR and the committee hopes to raise money to pay for the research.
Huettl estimates an initial cost of $300,000. DCCC plans to initiate a fund-raising campaign and is looking for private investors to help finance the project.
The group hopes Zequanox will be registered by the Environmental Protection Agency (EPA) for use in pipes later this summer and testing to begin in open waters next year.
“Getting the testing done is a start,” Huettl said. “The point is to get it started here in Minnesota and we would be the leaders, being that we have a number of lakes that need to be protected and nothing has been done to date.”
IS IT SAFE?
After testing is conducted in the lake, Molloy and Huettl expect the Zequanox would be allowed to disperse into the rest of the lake. They also do not anticipate the lakes would be closed during this period.
Molloy said dead bacterial cells would be used to combat the mussels, but a higher density of cells would be required.
“It kills [the zebra mussels’] digestive gland,” he explained. “Whether the cell is live or dead has no bearing on it because it is intoxication. It is not infection.”
Osgood said Zequanox would be reviewed thoroughly by the EPA.
“In my opinion, this stuff is safe,” he said. He later clarified his belief that after the EPA granted its approval for Zequanox applications in the lakes, it would be safe for humans.
But live pseudomonas fluorescens may wreak havoc on some humans, such as those that are immunocompromised, according to recent studies. The question is, will dead bacteria also affect humans?
Some community members were skeptical about Zequanox, although most were positive, according to Huettl.
“Being active and putting [Zequanox] into the lake has raised the hackles more so than what they do on their lawn spraying weed killer and those kinds of things,” she said. “You see permits all over the lakeshore for killing 50 feet of weeds. They don’t think anything of it, but, oh, put Zequanox in to kill a zebra mussel and, oh, my God, we’re poisoning the water.”
The DCCC is looking into the possibility of bringing in a company to make Zequanox here.
If a manufacturing plant was built in the Alexandria area, it could produce Zequanox for other lakes.
“We are looking at this as an entrepreneurial adventure, for someone here in Minnesota,” Huettl said. “Doing nothing is old news.”
“Doing nothing has impacts,” he said. “I don’t think this chain of lakes has seen the full impact yet of zebra mussels. It is very early in the infestation.”
Osgood is executive director of the Lake Minnetonka Association. Zebra mussels were first discovered in Lake Minnetonka last July in small quantities.
“This year they are on virtually every rock,” he said. “They are exploding.”
“This is it,” Huettl said. “The chemicals that are out there that would be used are much more harmful.”
“The risks are so much higher,” Molloy added. “You’ll never eliminate risks. Every pesticide has risks.”
And Osgood said, “This is the only game in town. There really is nothing else.”
See upcoming issues of the Echo Press for more information about zebra mussels and safety concerns.