Invasive mussels found in and around Port of West Sacramento, CA officials say
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- California wildlife officials confirm golden mussels at Port of West Sacramento.
- DWR detected golden mussels in the Sacramento‑San Joaquin Delta in 2024.
- Sacramento County declared a local emergency to combat rapid golden mussel spread.
The California Department of Fish and Wildlife confirmed Saturday that golden mussels have been found in and around the Port of West Sacramento, the northernmost detection of the invasive species to date.
The California Department of Water Resources detected the golden mussel, a freshwater mollusk native to Asia, in the Sacramento-San Joaquin Delta in 2024. This marked the first sighting of the organism in North America.
Following the Department of Water Resources’ initial discovery, it made observations of mussels at numerous other locations throughout the Delta. According to a 2024 news release from state fish and wildlife officials, the mussels pose “a significant immediate threat to the ecological health of the Delta and all waters of the state, water conveyance systems, infrastructure and water quality.”
Golden mussels attach to nearly all underwater surfaces, including boats, ropes and buoys. They can alter the marine food web and diminish water quality by clogging pipes and drains.
The mussel population in the Port of West Sacramento is believed to have stemmed from a source population within the vicinity, according to a press release from the Department of Fish and Wildlife.
“Anyone boating or recreating on waterways around the Sacramento area, and throughout the Delta, should take precautions to stop the spread of golden mussel further upstream and overland on watercraft and equipment used in mussel-infested waters,” the release reads.
Lake Tahoe officials in late May stopped a watercraft carrying golden mussels from entering the lake. The vessel, which came from the Sacramento area, confirmed the need for full decontamination of boats accessing Lake Tahoe — a practice officials recently began implementing.
The rapid proliferation of golden mussel populations led the Sacramento County Board of Supervisors to declare a state of local emergency June 16. The county has pledged to work with water agencies, environmental partners and state officials to mitigate the spread of the invasive species.
The Tahoe Regional Planning Agency said Thursday that authorities have intercepted and prevented six attempted illegal boat launches at Lake Tahoe that had attempted to bypass inspections that would have searched for golden mussels.
This story was originally published June 27, 2026 at 12:19 PM.