Invasive species threatens ecosystems and water infrastructure in San Bernardino and Los Angeles counties
In September 2025, the invasive golden mussel was discovered in Silverwood Lake (San Bernardino County) and Pyramid Lake (Los Angeles County), marking the southernmost detection of this species in California. Native to China and Southeast Asia, the golden mussel poses significant risks to local ecosystems and water infrastructure.
First identified in the Sacramento-San Joaquin Delta in October 2024, the golden mussel has since expanded its range. Its ability to reproduce quickly and attach to various surfaces allows it to spread via boats and watercraft, posing challenges for containment efforts.
Impact on Ecosystems and Infrastructure
The golden mussel’s feeding habits can lead to the depletion of aquatic plants, disrupting food sources for native species. Additionally, its tendency to encrust hard surfaces can clog water intake pipes, damage boat engines, and interfere with hydroelectric facilities, leading to increased maintenance costs.
State Response Measures
In response to the infestation, the California Department of Water Resources (DWR), California Department of Fish and Wildlife (CDFW), and California State Parks have implemented new boating protocols. These include mandatory vessel inspections upon exiting Silverwood Lake, removal of drain plugs, and advisories for thorough cleaning and drying of boats to prevent further spread.
Given the daily transfer of water from Silverwood Lake to Lake Perris, officials anticipate that the golden mussel may soon reach Riverside County. Monitoring efforts are ongoing, and the public is urged to report any sightings to local authorities.
How to Report a Golden Mussel Sighting
Preventing the further spread of the golden mussel requires community cooperation. Boaters and lake visitors are encouraged to adhere to the new protocols and remain vigilant. Early detection and reporting are vital to protecting California’s water resources and ecosystems.
If you observe a golden mussel in California, it’s crucial to report it promptly to help prevent its spread. Here’s how you can report a sighting:
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Online: Visit the California Department of Fish and Wildlife’s Invasive Species Reporting page
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Email: Send an email with clear, close-up photos of the mussel, including an object for scale (like a coin or pen), to invasives@wildlife.ca.gov
- Phone: Call the California Invasive Species Hotline at (866) 440-9530 to report a sighting.
When reporting, please include:
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The exact location of the sighting.
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At least one clear, close-up photograph of the mussel.
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Your contact information for follow-up.
For more information on the golden mussel and how to prevent its spread, visit the California Department of Fish and Wildlife’s Golden Mussel page
