What would it take to get rid of the trillions of invasive zebra and quagga mussels that carpet the bottom of Great Lakes and inland lakes alike?
Nobody knows for sure.
Yet.
But copper ions, dead bacteria and even chili peppers all figure into potential solutions to a problem that plagues much of the Great Lakes and a growing number of inland lakes in Michigan.
The fingernail-sized zebra mussel and its cousin, the quagga mussel, are small creatures that create big pain, coating piers, boat slips and lake bottoms.
They arrived in Michigan in the early 1990s, and some estimates now place their numbers as high as 750 trillion. The mussels muscle out native species and disrupt the food chain by siphoning out nutrient-rich plankton that fish also need to survive.
But human ingenuity is making some inroads against the invaders.
Take, for example, the Dock Disk, which received a patent in December and is being marketed by the California-based startup 060Bio. It involves flexible foam discs, each about the size of a dinner plate, impregnated with an alloy of copper and zinc. It emits ions that the mussels find unsavory.
James Gregath of 060Bio says that spacing the $40 devices strategically around a boat slip could keep it mussel-free for a season.
“There are so many applications ahead once people accept that it actually works,” he said.
In theory, a device like the Dock Disk could work, said Seth Herbst, aquatic invasive species coordinator for the Michigan Department of Natural Resources’ fisheries division. He hasn’t seen test data on the device. But it’s one of a variety of controls that are being developed.
“Right now we have very limited tools available to us for controlling or potentially eradicating zebra mussels or quagga mussels,” Herbst said. “What we are currently lacking is technology or a tool that could be used to control zebra mussels on the large scale. Even in a small inland lake, that technology and control just isn’t currently out there.”
One key problem: some controls that kill zebra and quagga mussels also would kill desirable native mussels and clams.
One product that has been successfully used in specific spots such as water intake pipes and outlets where mussels congregate is called Zequanox. Developed by California-based Marrone Bio Innovations and manufactured in Michigan, it uses a killed bacteria, pseudomonas fluorescens, to poison the mussels.
“It has been effective in controlling mussels around discharge and intake pipes,” Herbst said. “It hasn’t been shown to be effective on the scale of a lake.”
There also are paints designed to keep mussels from adhering to docks, boat slips or pipes, said Dan O’Keefe, southwest district extension educator with Michigan Sea Grant.
“There are a variety of different types including one I saw that is based on chili peppers,” he said. Others are based on copper or chemicals.
“The whole idea is just that there are some things they won’t attach to,” he said.
Some inland lakes that were overrun by mussels in recent years have seen populations taper off a little. That may have to do with water temperatures or the natural cycle of invasive species, which tends to boom and bust.
The best way to inhibit the spread of mussels still is to make sure boats are clean before moving them from one body of water to another, he said.
“The mantra is ‘clean, drain, dry,’” he said. “You’re required to drain all the water out of your boat before transporting the boat to another area.”
That’s key because microscopic mussel larvae known as velagers may tag along in that water.
“You could have a cup of water in the bottom of your boat and it could have these in it,” O’Keefe said. Power wash boats with hot water and make sure to discard any plant materials.
Contact Kathleen Lavey at (517) 377-1251 or klavey@lsj.com. Follow her on Twitter @kathleenlavey.
Link to article from Lansing State Journal http://on.lsj.com/2m7drlo