By itself, the Zebra mussel is small and harmless. But the tiny crustacean, believed to have come to U.S. shores from the Black and Caspian seas in Europe and Asia, reproduces quickly and in enormous numbers.

The first infestation of zebra mussels in Marion Reservoir was discovered last week by a fishing angler who saw one attached to a stone in the water, according to a state worker.

Matt Farmer, wildlife biology technician for the Kansas Department of Wildlife and Parks, whose office is located at the reservoir’s broken bridge area, said the mussels are a foreign introduction that originated in the Black and Caspian Seas between Europe and Asia.

They are thought to have been introduced in ships’ ballast water dumped in the Great Lakes.

He said Jason Goeckler, KDWP aquatic nuisance species coordinator from Emporia, was called to Marion to confirm the find. Goeckler not only confirmed the report, but discovered two more zebra mussels at the dam.

“That means we have a reproducing population of the mussels at Marion,” Farmer said.

And reproduce they will—big time. Farmer said a juvenile zebra mussel is capable of reproduction almost the moment it attaches to a home, and can produce up to 100,000 eggs a year.

That’s nothing compared to the mature females, though. Farmer said a single female is capable of laying more than a million eggs annually.

Life expectancy for zebra mussels is four to six years, according to an environmental science Web site.

The mussels’ rapid reproduction rate is the main reason they become a problem, Farmer said.

He said he doesn’t believe the general public will be able to notice the mussels much this year. The angler, whom Farmer declined to identify, that saw the first mussel had some expertise..

A year from this fall, given the mussel’s reproductive power, Farmer said the general public will become aware of zebra mussels at the lake.

Bad outcomes

The city water plants at Marion and Hillsboro will have to start learning to deal with the “D-shaped, dime-sized” mussels that attach in profusion to block water intakes and drains.

Power plants and other water systems downstream also will have to prepare as the mussels move down to inhabit new portions of the Neosho and Cottonwood basins.

Farmer said the mussels don’t threaten humans in a direct, physical way except by cutting swimmers’ feet with their sharp shells. He noted that swimmers at El Dorado Lake have had to wear sandals or water shoes for some time now to protect their feet from the striped zebra mussels.

The zebra mussels also out-compete native species of fish and clams for the food supply of floating algae and plankton that many of them depend on, he said.

The mussels can make the water much clearer with their voracious and numerous appetites, but that doesn’t mean the water is actually clean, Farmer said.

“A little bit of color to the water is more indicative of health,” he said.

Fighting back

At El Dorado Lake, Farmer said species such as blue catfish that eat the zebra mussels are being released, but they can’t keep up with mussel reproduction to stop the problems.

The mussels have already turned up at other Kansas reservoirs, such as Cheney, Perry and smaller lakes.

Other lakes downstream, such as John Redmond where Wolf Creek Nuclear Power Plant may have to deal with them clogging its water draw, are awaiting their arrival.

Zebra mussels are also at Missouri’s Lake of the Ozarks and Lake Taneycomo, plus Oklahoma’s Grand Lake of the Cherokees.

Missouri state biologists have confirmed zebra mussels in both the Mississippi and Missouri rivers. Theoret­ically, they say, the mussels will be moving upstream into basins such as the Neosho and are confirmed in at least 12 states.

Causes for the spread

Carelessness in cleaning mussels from crafts on the part of boat-owners moving from lake to lake is blamed for the mussels’ spread. But Farmer said the situation is partly understandable. The newly hatched mussels are microscopic, so the boat owners might not have realized they were transferring a problem, he said.

Farmer said the mussels are now costing more than a billion dollars annually in control measures in the United States.

Chemical controls aren’t practical, he said, because the chemicals also can kill native mussels and other species.

Some water and power plants have had to resort to tedious removal of the mussels by hand from water intakes, he said.

KDWP recommends that lake users learn to identify nuisance species such as the zebra mussels.

The agency says never to move fish or water from one body of water to another, and to empty bait buckets on dry land, not into lakes.

KDWP recommends inspecting boats, trailers, skis, anchors and all other equipment for any organisms or vegetation.

To clean equipment, and kill the mussels in the process, the agency says either to wash with 140-degree water, a 10 percent chlorine and water solution, or to dry for at least five days.

The mussels aren’t recommended as a food source for humans, Farmer said, because it would take too many of the tiny crustacean shelled out to make a mouthful.

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