Invasive golden mussels confirmed in Port of West Sacramento for first time

The invasive golden mussel has now been confirmed in the Port of West Sacramento, marking the species' northernmost detection in California since it was first discovered in Stockton in 2024, wildlife officials announced Saturday.

The California Department of Fish and Wildlife said the mussels found in West Sacramento represent an established local population rather than a one-time introduction from a contaminated boat.

Officials have notified the cities of West Sacramento and Sacramento, along with Sacramento and Yolo counties, about the discovery.

The detection comes as communities across the Sacramento-San Joaquin Delta continue to grapple with the invasive species, which can rapidly reproduce and attach themselves to hard surfaces, clogging water intake pipes and damaging infrastructure while disrupting native ecosystems.

Golden mussels were first detected in California in October 2024 at the Port of Stockton, marking the species' first known appearance in North America

The discovery in West Sacramento follows growing concerns in Stockton, where city leaders declared a local emergency over the impact of golden mussels on the city's drinking water system.

State wildlife officials continue to urge boaters and anyone using California waterways to thoroughly clean, drain and dry their watercraft and equipment before moving between bodies of water in an effort to slow the spread of the invasive species.