Invasive zebra mussels arrive in Northwest on pleasure boats

SEATTLE — This week's discovery of zebra mussels on a recreational boat traveling through Washington is the most recent sign that Pacific Northwest waters may be in danger of infestation by this tiny but mighty invasive species, a state official says.

Inspectors at truck weigh stations have discovered zebra mussels on four boats in Washington since December, but since few recreational vessels are stopped at weigh stations, most are not inspected by the Washington State Patrol.

"I feel like we've only caught the tip of the iceberg," said Pam Meacham, assistant aquatic invasive species coordinator for the Washington Department of Fish and Wildlife.

Zebra mussels reproduce quickly and can clog pipes in municipal water systems and ruin boat motors. They were inadvertently introduced into waters near the Great Lakes in the mid-1980s and government officials have worked with sport fishing groups to keep the invaders from spreading.

An invasion of zebra mussels also can impact a lake ecosystem as the creatures attach themselves to clams and other water life and eat all the food out of the water.

"Fisheries in the Great Lakes have collapsed," Meacham said Friday, adding that the infestation has spread west in recent years and is now a problem in California and Nevada. No zebra mussels have been found in Washington waters.

The boat stopped Monday at the weigh station on Interstate 5 northbound near Ridgefield was targeted by biologists from Oregon Fish and Wildlife who noticed the boat and called Washington officials to have it inspected, Meacham said. The boat, which had been salvaged after sinking in an infested lake in the Midwest, was on its way to Vancouver Island, British Columbia.

Another boat was stopped in Cle Elum on the same day and sent to a boat yard to have its zebra mussels removed, she said.

"Zebra mussels have been considered a threat to our waters for a long time," she said. In 1998, the state Legislature formed a task force to address this aquatic threat as well as problems with green crabs. Meacham and her boss are the state coordinators for the Aquatic Nuisance Species Task Force.

Since 2000, the Washington State Patrol has been asked to inspect boats that pass through truck weigh stations as they are being commercially hauled.

"It's a very real threat. They can get here easily," Meacham said, adding that the program has discovered mussels on a number of boats and the owners were told to take action to prevent the mussels from getting in state waters.

Meacham said Friday she was surprised at the response to this week's zebra-mussel discovery, since she and others have been working to educate the public about this problem for many years.

Large recreational lakes that are visited by people who travel around with their boats are most in danger of infestation, Meacham said. Officials from the Department of Fish and Wildlife plan to be at every fishing tournament in Washington this year to educate boaters about the problem.

Meacham said boaters need to learn where to look on and in their boats for the tiny mollusks and how to clean their vessels to remove any zebra mussels or other invasive species so they won't be responsible for spreading a problem.