WILSON LAKE -- They were the words Tommie Berger had been expecting but dreaded hearing: Zebra mussels had arrived at Wilson Lake.

"We've kind of been expecting it because of how many people are coming here from El Dorado and Cheney," fisheries biologist Berger said in a candid interview, the first since the aquatic pest was found in Wilson.

Zebra mussels can't swim, relying instead on water waves to move them about.

"Someone brought them here," said Jason Goeckler, coordinator for aquatic nuisance species for the Kansas Department of Wildlife and Parks, either in a boat or a bucket.

Seven Kansas lakes and downstream rivers now contain zebra mussels, small clams that breed profusely and attach to virtually anything that remains stationary for long.

Zebra mussels are especially troublesome for lakes that supply public water-supply systems because they often clog pipes and pumps used to move the water.

Although Wilson currently doesn't provide any public water supplies, it is the subject of review by the Kansas Water Office and U.S. Army Corps of Engineers to determine how much water the lake can provide.

The cities of Hays and Russell both have identified Wilson as its best long-term solution. If nothing else, the mussels likely will mean extra protective devices, which could add considerably to an already expensive project.

The zebra mussel discovery came Oct. 6, when a boat was pulled from the water for winterizing.

Berger was given the pests for identification.

The next day, two other boats were pulled from the lake and more mussels were found.

So Berger started investigating further.

"Once we find them on a boat, then we start looking in the lake," he said.

With water levels about a foot higher than normal, Berger donned his waders and started overturning rocks that would have been under water all summer.

He found zebra mussels on the rocks, although they are not in great numbers.

Not yet.

"Each one produces over a million eggs a year," Goeckler said.

Based on the size of the mussels -- smaller than a fingernail -- Goeckler thinks they were introduced sometime last year.

"Due to the size," Berger said, "it looks like they were introduced last year. Sometime in 2008.

"They're very low density at this time," Goeckler said.

"It appears they have built up enough numbers that we can say they're here," Berger said.

Now, Wilson is added to the list of infamy for lakes that have zebra mussels.

Soon, Berger will be posting signs that Wilson has zebra mussels, alerting boaters to drain any lake water from the boat, allow it to dry out or wash it down with hot water.

"It takes two minutes at the ramp," Goeckler said of draining water from a boat coming out of a lake. "And if you want to go the next day, go to the car wash."

Heated water from a car wash is hot enough to kill the pests.

Worst-case scenario, boaters can use a bit of bleach to kill the mussels, although it is not so kind on the environment.

"We certainly don't want them in Cedar Bluff, Webster, Kirwin or Sebelius," Berger said.

Or Glen Elder, Goeckler added.

While zebra mussels are virtually impossible to get rid of, Berger is holding out hope that Wilson might have a fighting chance.

"Blue catfish are pretty much known to eat zebra mussels," he said, and have been stocked at Wilson. "Most of the water where zebra mussels are in, we are already stocking blue cats."

Red-eared sunfish, known as shell-crackers in the south, are being considered, but often don't do well in big lakes.

"Some of the guys are trying everything they can to keep them under control," he said.

Zebra mussels have a five-year lifespan, so there will be peaks and valleys as time goes on.

"We're looking at the first population peak to be about three years from now," Berger said. "That's when the adults die off and the shells open up and that's when the cuts will spike."

The opened shells are sharp, responsible for cuts. At El Dorado Reservoir, where they were first found, they covered virtually everything.

"They'll cut your feet and the feet of your pets that go wading," Goeckler said.

This is Wilson's second exposure to aquatic pests, the first coming in the form of white perch.

"Here, we've got them under control," Berger said of the perch, primarily because they grow large enough to attract anglers. "Here, due to the clear water, the number of predators, they have been kept in check. And that's good."

The average white perch being caught, he said, is about 10 inches long, weighing half a pound.

"They eat real good, so therefore there's a lot of people interested in them," he said.

No matter the size, anglers are not to return white perch to the lake.

But that's white perch.

"What the zebra mussels do here, nobody knows," he said. "We've got extremely clear water."

That means fewer zooplanton, the tiny plant materials that mussels filter-feed upon.

But, Goeckler cautioned, "they're eating the good stuff."

There's also the question of what effect the salty water from Wilson will have on mussels.

But there's also the threat of zebra mussels going down the Saline River, eventually dumping into the Solomon and Smoky Hill rivers, which collectively become the Kansas River. Wilson releases water into the river every day.

"All the cities and every other user of water out of the Saline to the Smoky and Kansas are going to be impacted by this," Goeckler said.

"When you start thinking about all the possibilities, it's pretty scary," he said.

Other than blue catfish and perhaps the red-eared sunfish, there's little else that can be done.

To be sure, chemical treatments have been tried, but on much smaller bodies of water.

Current technology, Goeckler said, essentially sanitizes the lake and is too expensive for a lake of Wilson's size -- about 5,000 acres of water.

"Our goal is to keep the spread to a minimum," he said. "We're at seven (lakes) now. We'd like to keep it at seven.

"We can prevent this spread," Goeckler said. "It just takes a little bit of time.

"We can beat this dog."