Pesticide That Kills Zebra, Quagga Mussels May Be Tested On Northern Wisconsin Lake

Zequanox, a pesticide that kills quagga and zebra mussels, may be tested in a northern Wisconsin lake this summer.

The pesticide is already registered with the U.S. Environmental Protection Agency and state of Wisconsin for use to kill quagga and zebra mussels in confined areas, like water intake pipes.

Now, the U.S. Geological Survey office in La Crosse has requested a permit to apply Zequanox one time to Keyes Lake in Florence County, in six enclosures covering about 200 square yards.

The Wisconsin Department of Agriculture Trade and Consumer Protection (DATCAP) has completed an environmental assessment on the requested use of Zequanox. DATCAP spokesperson Donna Gilson says the review found no potential environmental harm that would require extra precaution beyond what’s listed on the product label.

“It’s non-toxic to mammals and to birds,” said Gilson. “It’s highly selective to the family of mussels to which zebra and quagga mussels belong.”

Gilson says Zequanox is a powder made from killed bacteria that the mussels filter out of water for food. The powder works by disrupting the mussels’ digestive systems.

A DATCAP environmental enforcement specialist would observe the application of the pesticide, which is tentatively scheduled to take place between July 15 and August 15. The public may comment on the proposed use of the pesticide until a week from Thursday.