Associated Press - May 20, 2009 10:25 PM ET

BOISE, Idaho (AP) - Authorities in Idaho and Washington say they have detained a boat believed to be contaminated by an invasive mussel, stopping the craft before it could enter Northwest waters still free of the aquatic menace.

The Idaho Department of Agriculture announced Wednesday that it was able to track and detain the boat, which was destined for Spokane, Wash., and traveled through Idaho, Montana, Utah and Arizona. Authorities say the boat was last used in Nevada's Lake Mead, which is infested with zebra and quagga mussels.

The 26-foot boat, named "Hello," is being held in Spokane. Officials have not yet identified the mussel attached to the boat.

Efforts to track the vessel started when a Utah resident noticed a mussel on the craft traveling north on Interstate 15 into Montana.

Invasive mussels reproduce and spread rapidly, clogging machinery and water pipes and destroying aquatic ecosystems.

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