MADISON, Wis. -

An expert with UW-Madison's Center for Limnology said a chemical used to eliminate invasive zebra mussel populations in Minnesota wouldn't work in major Madison lakes infested by the mollusc.

CBS affiliate WCCO reports the chemical, which is a copper-based pesticide, has been used to target zebra mussels in Twin Cities-area lakes.

The chemical is considered to be safe for use by the Environmental Protection Agency.

But Michael Spear, a graduate student who studies invasive species, said Madison's major lakes are too large for the chemical to eliminate the mussels.

"There's too many refuges for these zebra mussels that are already spread across the lake to avoid these chemicals and recover from them," Spear said.

Currently, lakes Mendota, Monona and Waubesa are infested by the zebra mussel, according to the Dane County Lakes and Watershed Commission.

Signs encouraging boaters to inspect for and remove the mussels from their boats are installed at boat ramps in the infested lakes, but Spear said it's likely the mussels will eventually spread to the rest of the lakes in the Yahara watershed.

"It's only a matter of time, because the lakes are connected, that it would spread down the chain," Spear said.

A solution for the mussel infestation isn't likely to come anytime soon, Spear said.

"There's probably nothing we can do other than hope the system naturally eliminates them," Spear said. "That's not a likely scenario."

To learn more about zebra mussels, visit the Wisconsin Department of Natural Resources' website.