WDFW busy with boat inspections for mussels


Washington Department of Fish and Wildlife surpassed 36,000 boat inspections this summer in the quest to keep zebra/quagga mussels out of waterways and lakes.

First found in the Great Lakes in the 1980s, zebra quagga mussels have been found in Texas, California, Utah, Nevada and Colorado but have yet to be found in Washington waters.

These mussels can damage hydroelectric and irrigation infrastructure since they attach to hard surfaces in high densities. This means clogged intakes and pipes. Mussels cause over $300 million to $500 million in damage annually. If they were to get into Washington waters, the damage could cost the state $100 million annually.

In March 2021, several states reported the presence of both live and dead zebra mussels at pet store retailers nationwide. Retailers quickly acted to pull the product from shelves and place them in quarantine. The wholesale distributors out of California and Florida were notified, and shipments into the country ceased.

Washington’s four inspection stations are in Cle Elum, Tri-Cities, Stateline and Clarkston.

When WDFW officials find mussels, they wash down the boat with 140-degree water to kill them and then scrape them off.

Zebra mussels can also be found in Marimo moss balls. They are usually about the size of an adult fingernail, but can be as large as 2 inches or as small as a sesame seed.

These mussels have also been found in aquariums.

Twelve boats with mussels were purchased out-of-state and came into Washington for the first time. During the pandemic, Washington has seen a jump in the number of boat purchases from out of state — more than 1,000 in 2020 and 2021, but these numbers have dropped in the past two years. 

To report invasive mussels in aquariums or other places, go to https://invasivespecies.wa.gov/report-a-sighting/.