Golden mussels have been confirmed in over 50 locations across California

Golden mussels, a destructive species from Asia, are concentrated in the Sacramento-San Jaoquin River Delta, according to California Department of Fish and Wildlife surveys.

A map showing a dot for each location golden mussel sightings have been confirmed. The dots are primarily located in the Sacramento-San Joaquin River Delta.
Note: Data reflects the first record of golden mussels found in a particular waterbody or stretch of river or stream. Data collected on July 14, 2025.
Chart: Natasha Uzcátegui-Liggett, CalMattersSource: California Department of Fish and Wildlife, Invasive Species ProgramEmbed