Boat-washing sites planned to combat zebra mussels

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Times staff report

Boaters out on Minnesota lakes this weekend could encounter new boat-washing stations and inspectors designed to prevent the spread of zebra mussels and other invasive species.

The state Department of Natural Resources purchased the portable decontamination units with funding provided by the Legislature to combat invasive species. The units are capable of spraying 160-degree water at high pressure to remove zebra mussels from boat hulls, livewells and other areas that can harbor invasive species.

The DNR plans to have the units along with trained staff at public accesses on high-traffic lakes that are infested with zebra mussels, such as Mille Lacs, Minnetonka and Pelican Lake in Otter Tail County. Only boats that don’t pass an inspection will need to be decontaminated with the new equipment.

The DNR plans to increase the number of decontamination units from three to a fleet of 20 or more by next summer.

The agency encourages boaters to follow a few steps before leaving an access to ease the process:

» Leave a little extra time for the inspection.

» Remove visible aquatic plants and zebra mussels from boats and trailers.

» Drain water from your boat, livewell, bilge and impellor by removing drain plugs and opening water-draining devices. Also drain portable bait containers.

Gut wrencher: Researchers seek magic bullet to control mussels


Scientists have identified a new weapon to ward off two troublesome Great Lakes invaders: A bacterium strain that destroys their guts.

It may prove to be an environmentally friendly and effective method of controlling quagga and zebra mussels. Introduced to the lakes in the 1980s, the mussels eat up things like phytoplankton – food that native fish and other life depend upon.

They also clog things like the water intake pipes of power plants. Nowadays they are removed by hand or with the treatment of chemicals that can be harmful to the environment.

A strain of the bacterium, P. flourescens, destroys the bivalves’ digestive systems.

Daniel Molloy, a researcher at the New York State Museum, once helped develop an environmental safe method, using a bacterium, to kill black flies and mosquitoes. He had a hunch that a strain might be found to kill invasive mussels, says Molloy’s colleague Denise Mayer.

And they found it hiding in plain sight.

“[The bacterium] is ubiquitous, you know, common found all over the world. It’s everywhere, it’s on your fingers,” said Mayer, a lead research scientist at the museum which hosts scientists in a variety of areas.

Their research was backed, among others, by the Empire State Electric Energy Research Corporation and the U.S. Department of Energy’s National Energy Technology Laboratory.

“Our intent was really to provide a tool to the … power industry and such, to clean their pipes…to reduce the use of some of the chlorinated compounds,” Mayer said.

The method isn’t designed for open water use so it doesn’t solve the problem of the mussels’ impact on the ecosystem.

Chemicals like chlorine can harm more than just the mussels, Mayer says.

And power industries are interested in getting rid of current methods, she says.

“Some of the biggest supporters, the Department of Energy, you know, power, they want a different method to use,” Mayer said. “So it’s not like they’re out there saying, we don’t care we’ll apply this to the environment. They really … would like to have an alternative.”

Typically the bacterium is associated with plant roots and helps the plant ward off fungi and disease.

But it also contains a chemical that is exclusively harmful to the two mussels and destroys their digestive systems. Other critters tested, like fish and other mussels, are unaffected by it.

The bacterium is a dish best served dead. Live cells could make fish sick, Mayer said.

“The cells are actually dead, so it’s acting like a pill .… it’s giving the mussels something to grab onto.” Mayer said.

The researchers screened more than 700 bacterial strains in search of the one that would do the trick.

“What they were able to do was pretty amazing. It’s more than just a needle in haystack,” said Sarahann Rackl, an Invasive Mussel Project Manager at Marrone Bio Innovations.

The museum then looked for a partner to commercialize the bacterium into a product.

And Marrone Bio Innovations answered the call. The California company focuses on environmentally friendly solutions to pest management. The company and the museum shared a $500,000 award from the National Science Foundation to aid in the bacterium’s development and commercialization. This year the company received another $600,000 from the foundation.

It is expected to be available in March under the name Zequanox.

“We feel that this is another product in the toolbox for people to use,” Rackl said.

“There’s a lot of value and potential value in this product because it’s environmentally selective and benign.”

And the product won’t expose people to harmful chemicals, she says.

And time is money. Chlorine treatments, if done properly can take 7 to 10 days or longer, she says. Zequanox takes six hours.

DTE Energy spends between $100,000 and $500,000 a year controlling mussels in its six Michigan power plants, said Gary Longton, a DTE senior environmental engineering technician. The mussels clog pipes that draw in water to cool equipment.

Right now DTE employs divers to clean pumphouses with the same industrial commercial-grade scrubbers designed to scrape barnacles off of boat hulls. Or the company treats them with chlorine or sodium hypochlorite.

“Detroit Edison knows their business and they have chosen primarily mechanical because it’s the cheapest form, they’re no dumbbells,” said Don Schloesser a research biologist at the U.S. Geological Survey Great Lakes Science Center.

Longton says that the company is always open to new and effective methods to rid itself of the nuisances. He says that salesmen test strips different coatings in the pump houses. Once it was cayenne pepper.

“We’re always open for the magic bullet,” he said.

“If anyone came up with the magic bullet they could be a very rich and famous person,” he said, “and no one has come up with a magic bullet yet.”

Green Lake group in Spicer, Minn., looks to be at forefront in stopping zebra mussels

Taking on zebra mussels … Some reason for optimism

By: Tom Cherveny, West Central Tribune

SPICER — Like bracing for an uninvited guest to ring the doorbell, zebra mussels seem closer by the day.

They’ve established themselves in the Lake Le Homme Dieu chain of lakes in Douglas County, less than an hour’s drive away.

They’re proliferating rapidly in Lake Minnetonka, which has now been dubbed a “super spreader’’ due to the threat that the many boaters using the lake could spread the invasive aquatic species.

Yet, for the first time, there’s also a sense of optimism and there’s a greater resolve then ever, according to Terry Frazee with the Green Lakes Property Owners Association.

The Green Lake association is partnering with Minnesota Waters, which represents lakes associations across the state, and the lakes associations in Douglas County and Lake Minnetonka to research a promising tool in the battle to stop the mussels.

It’s a commercial product known as Zeaquanox. It offers the promise of helping control the invasive species.

“This is the light at the end of the tunnel we have not had,’’ said Frazee.

Developed 20 years ago by Dr. Daniel Molloy, a scientist with the New York State Museum, Zeaquanox is a strain of bacteria called Pseudomonas fluorescens. The bacteria are found naturally just about everywhere, from the ground we walk on to the milk we drink.

The bacteria are selectively toxic to zebra and quagga mussels when ingested by the invasive species.

In the case of Zeaquanox, the bacteria are killed. The dead bacteria cells retain the toxin that kills the zebra mussels. It causes the cells in the mussels’ digestive systems to hemorrhage.

The product is not harmful to native mussels, waterfowl or fish, and poses no risk to people, according to Frazee and Lois Sinn Lindquist, executive director of Minnesota Waters.

The three partners intend to be at the forefront in researching whether the product can effectively be used to control zebra mussels in Minnesota lakes.

Zeaquanox is already being used by power companies in place of chlorine to keep water intake pipes clear of the invasive species. Its toxicity to zebra mussels is 100 percent when present in high concentrations in the intake pipes and other closed systems.

But can it be effectively used in lakes, where it will be diluted and where it will be far more difficult to apply the product where it is most needed? And, can the product be made available at a reasonable cost for large-scale use?

These are among the questions the partners hope to be among the first to answer.

Having a possible tool to control zebra mussels is not the only reason for the optimism that’s starting to show itself, according to the partners.

Frazee and Lindquist noted that recent state legislation requiring boaters to drain their watercraft and new funding for research to control invasive aquatic species are all positive signs.

Lindquist said she was also encouraged by a recent visit with Tom Landwehr, new director of the Minnesota Department of Natural Resources. He made clear the department’s commitment to stopping the invasive species, she said.

Containment and keeping the zebra mussels out of local waters remains the number one priority, said Frazee. “Don’t move a mussel’’ and other campaigns aimed at heightening public awareness are the first line of defense.

Or as Lindquist said it: “Spread the message, not the mussel.’’

Zebra mussels in Lake Minnetonka

TOM MEERSMAN, Star Tribune

Zebra mussels have invaded Lake Minnetonka, a breach of the state’s defenses against invasive species that threatens to dramatically change the character of Minnesota’s 10th-largest lake within just a few years.

Department of Natural Resources biologists confirmed Wednesday that a small number of mussels are attached to rocks along the shore, and their size suggests that a reproducing population has been in the lake for at least a year.

In places where they’ve become established, the fingernail-sized mussels proliferate by the millions, consume food needed by fish, clog water intake pipes, ruin fish spawning beds and litter beaches and shallow areas with razor-sharp shells.

The mussels were found on the east side of Wayzata Bay near Hwy. 101. That’s not far from the lake’s outlet to Minnehaha Creek, raising fears that the mussels may spread into that waterway, or may have done so already. Minnehaha Creek is connected to lakes Nokomis and Hiawatha in Minneapolis.

For years DNR officials have worked with the Lake Minnetonka Conservation District and others to educate boaters and anglers to prevent the spread of zebra mussels. They also inspected boats and trailers and directed owners to remove plants, mussels and water from bait buckets and vessels that traveled in infested lakes and rivers. The efforts may have bought some time, but they didn’t stop the mussels’ entry into Minnetonka.

“Unfortunately, zebra mussels still found their way to the lake,” said Luke Skinner, supervisor of DNR’s invasive species program.

The discovery was dreaded news for Dick Osgood, president of the Lake Minnetonka Association, which represents about 600 lakeshore owners and businesses.

“This has been our fear all along, and keeping them out has been our top priority for the last ten years,” said Osgood.
Lake Minnetonka is the most heavily used lake in the state, he said, with an estimated 200,000 boats plying its channels, bays and open water annually.

With that amount of exposure, the discovery of mussels was not unexpected, said Osgood, but it was still a major disappointment.

“Bottom line is, I think they’re here to stay,” he said. “Not that we won’t do everything possible in rapid response, but I think it’ll change the lake forever.”

Osgood and representatives of the Minnehaha Creek Watershed District plan to do a quick assessment of the lake to see if they can find mussels in other places. There’s a chance, he said, that if they are only in one area, the mussels could be removed or killed before they spread further.

DNR officials said that the number of zebra mussels found was very low and that they would investigate the situation this week and beyond, including an extensive survey of the lake later this summer.

Osgood advocates limiting boat traffic in the infested waters, at least until the extent of the invasion is better understood.
In other places, he said, the discovery of zebra mussels is usually followed by 1 to 3 years of “lag time” in which a few more infested areas are found. At some point, usually about five years after the initial discovery, he said, the populations explode and the lakes start to change, sometimes unpredictably.

In some areas the numbers of different fish species increase or decrease, seeking a new balance as habitat and food sources change. Native mussels usually die out. And because zebra mussels constantly filter sediment and nutrients, water often becomes noticeably clearer.

That may please some, said Osgood, but it also means that light will penetrate deeper, boosting the growth of plants such as Eurasian water milfoil, an invasive that’s already a major nuisance and expense to control in Lake Minnetonka.

Resident spotted mussels

A local resident found the mussels in the lake early this week and reported them to the DNR. Skinner said that anyone else who finds mussels should contact the agency.

Zebra mussels are native to Eastern Europe and western Russia, and likely came to the Great Lakes in ballast water of ocean-going ships that traveled up the St. Lawrence Seaway. They were discovered near Detroit in 1988. Their first appearance in Minnesota was in 1989 in Duluth harbor, and they subsequently spread to 17 inland lakes, including Mille Lacs, Prior, and Le Homme Dieu and to portions of the Mississippi, St. Croix and Zumbro rivers.

Udai Singh, senior hydrologist and water quality specialist for the Minnehaha Creek Watershed District, said plans for what to do next are still very preliminary. If the mussels are firmly in the lake, he said, the district may install equipment at various locations downstream in Minnehaha Creek to check for them. The discovery in Minnetonka is “really unfortunate,” Singh said, and has already jump-started a new array of activities.

“Now since prevention is out the window, we will be more working in terms of control and management of them,” he said.
Tom Meersman •StarTribune