21 gallons of mussels pulled off tugboat

Washington’s watercraft inspectors earlier this month scrubbed 21 gallons of zebra and quagga mussels off a tugboat, the largest volume of the tiny mollusks to be pulled off a single vessel in seven years.

The boat was one of two infested boats that stopped at the Spokane watercraft inspection station on Jan. 7, according to the Washington Department of Fish and Wildlife. The other had just a few mussels on it.

Both boats had been docked in Lake Michigan, where zebra and quagga mussels were first detected in the 1980s.

The tiny shelled organisms stick to hard surfaces and are known to cause major damage to irrigation and hydroelectric infrastructure. They were introduced to the U.S. through ballast water on ships and have since been spread around the country.

Idaho had its first mussel detection in the Snake River near Twin Falls in 2024.

Mussels have not become established in Washington thanks in large part to the state’s check stations. Justin Bush, WDFW’s aquatic invasive species division manager, said in a statment that the agency has intercepted 127 mussel-fouled boats in the past five years.

“If just one made it to our waters, we would be addressing the consequences of invasive species introduction today,” Bush said.

The agency is seeking $7.2 million from the Washington Legislature to fund aquatic invasive species efforts.