SPOKANE - Zebra mussels, invasive species that could harm Washington fish and wildlife and damage hydroelectric dams and public water systems, were discovered this month on a large boat being trailered cross-country by commercial vehicle, the Washington Department of Fish and Wildlife (WDFW) reported today.
Despite the successful discovery at the Washington-Idaho border, WDFW officials are concerned that zebra mussels could be slipping in on smaller boats that are not required to stop at highway weigh stations.
Zebra mussels, fingernail-size freshwater mollusks native to the Black, Caspian and Aral Seas, were first introduced to the Great Lakes in 1986 in the ballast water of transoceanic ships. They can spread quickly, altering entire ecosystems of some waters by smothering native mussels and consuming food sources of other fish and wildlife.
The mussels have also cost industry, government and private citizens millions of dollars by clogging water intake pipes used for irrigation and municipal water supplies and damaging boat engines.
Zebra mussels are now found in at least 22 states and two Canadian provinces east of the continental divide. They spread by attaching to boats and other water-based recreational equipment.
On May 11, WDFW was alerted when a Washington State Patrol (WSP) officer at the Interstate 90 Port of Entry east of Spokane found live zebra mussels on the trim tabs of a 38-foot boat on its way from Tennessee to Washington's coast.
"Our nuisance species detection training paid off," said WDFW Regional Enforcement Captain Mike Whorton, who took the call from WSP's commercial vehicle inspector James J. Spencer.
With the help of Spokane Police Officer Brian L. Baldwin, Spencer detained the boat hauler until Whorton and WDFW officer Mike Sprecher arrived to collect information and make arrangements to send the boat to a decontamination site at a Bellingham marina.
The owner had attempted to clean the boat, Whorton said, but not thoroughly enough. Under federal and state laws, vessel owners and haulers are responsible for decontaminating against nuisance aquatic species, he explained, so enforcement action can be taken against them at interstate ports of entry.
Recently adopted Washington state law also now prohibits transport of any aquatic nuisance species on any size boats, trailers, fishing gear or bait wells, and allows state authorities to detain suspected carriers.
"Unfortunately, smaller boats don't have to stop at commercial ports like this one did, "Whorton said, "and we fear zebra mussels or other invasive plants and animals may be slipping by us."
Sometimes young zebra mussels are found in plants tangled on propellers or trailers, Whorton said. But often they can only be felt on the sides of boats, since they are too small to see. Adult zebra mussels might be seen attached in clusters to boats, but often hide in boat bilges, live wells, and motors.
Washington has been watching for zebra mussels for the past four years, said Pam Meacham, assistant coordinator for WDFW's aquatic invasive-species program. Several boats harboring the invasive species have been stopped and decontaminated before entering Washington waters, she said.
"So far, Washington is free of zebra mussels," Meacham said, "and we want to keep it that way. With thousands more recreationists heading our way in 2005 and 2006 to celebrate the two hundred year anniversary of the Lewis and Clark Expedition's travels in Washington, we need everyone's help. "
Boat owners can help by carefully inspecting and rigorously cleaning their vessels whenever leaving one water and heading for another, Meacham said, especially between states and provinces. Draining all water from boats and equipment, including bilges, live wells, bait buckets and coolers, is also critical.
For more information on zebra mussels, see Aquatic Nuisance Species on WDFW's website.