A naturally occurring substance that has been used to control invasive mussels in industrial water systems is being tested against those invaders in open waters in west-central Minnesota.
The product, called Zequanox, will be tested against zebra and quagga mussels in waterways at Lake Carlos State Park, north of Alexandria, the Minnesota Department of Natural Resources said last week.
Zequanox was approved by the Environmental Protection Agency in 2011 for use in controlling the invasive mussels, which clog industrial water systems such as power plant pipes, but little research has been conducted to evaluate its potential for controlling the invaders in natural ecosystems, the DNR said. It is not lethal to native mussels.
The research at Lake Carlos is being funded by the EPA's Great Lakes Restoration Initiative. It's being conducted by the DNR's invasive species program, along with the U.S. Geological Survey and New York State Museum's Field Research Laboratory.
"The main objective ... is to evaluate the potential of Zequanox to reduce the impacts of zebra mussels on native mussels," Nathan Olson, DNR aquatic invasive species specialist, said in the news release. "...This research is the first step to determine the potential of Zequanox to treat isolated, localized areas such as those around docks and boatlifts in waters where zebra mussels are newly discovered."
Last fall, zebra mussels taken from Lake Carlos were put into holding cages, which were then tossed back in the lake. Over the winter, the mussels attached to aluminum mesh trays within the cages. This month, the mesh trays were taken to a research trailer, where they're exposed to Zequanox, then placed back into the lake. After four weeks, they'll be examined to see what effect the treatment had.
According to Marrone Bio Innovations, a California company that produces Zequanox, it is composed of dead cells that the mussels consume. Once ingested, it destroys the mussel's digestive system.