Invasive Mussel News

Golden Mussel Detections in California

Sacramento-San Joaquin Delta

Rio Vista: July 1, 2025 – golden mussel veligers were detected by cross-polarized light microscopy (CPLM) in a plankton sample collected in the Sacramento River near Rio Vista, Solano County. The veligers were genetically identified via polymerase chain reaction (PCR) analysis. On September 4, 2025, one adult golden mussel was detected at the same location and genetically identified via PCR analysis.

New Bridge Marina: July 29, 2025 – three adult mussels were discovered on the underside of the slips at New Bridge Marina by the Highway 160 Bridge in Antioch, Contra Costa County. The mussels were genetically identified as golden mussel using PCR analysis and DNA sequencing.

Pittsburgh Yacht Club: July 29, 2025 – one mussel was discovered on the underside of a slip at Pittsburgh Yacht Club in Pittsburgh, Contra Costa County. The mussels were genetically identified as golden mussel using PCR analysis and DNA sequencing.

South Delta: September 3, 2025 – adult mussels were discovered in Grant Line Canal and at two sites in the Upper Old River. All 3 sites are in San Joaquin County. The adult mussels were morphologically identified.

Pirates Lair Marina: September 4, 2025 – adult mussels were discovered at Pirate Lair Marina, Sacramento County, attached to docks. The adult mussels were morphologically identified.

San Joaquin River: September 4, 2025 – 100+ juvenile mussels were detected in San Joaquin River downstream of Mossdale Crossing, San Joaquin County, attached to flow monitoring equipment. The mussels were morphologically identified.

Patterson Pass Water Treatment Plant

August 14, 2025 – a single adult golden mussel was discovered in a strainer on a raw water sample line during routine cleaning at the Patterson Pass Water Treatment Plant in Livermore, Alameda County. The veligers were genetically identified via PCR analysis and DNA sequencing.

Chrisman Wind Gap Pumping Plant

August 22, 2025 – 25 adult golden mussels were discovered on the man doors of pump units at Chrisman Wind Gap Pumping Plant (just south of Wheeler Ridge Pumping Plant on the California Aqueduct), Kern County. The adult mussels were morphologically identified.

Silverwood Lake

August 26, 2025 – a golden mussel veliger was detected by CPLM in a plankton sample collected at the Silverwood Lake outlet. The veligers were genetically identified via PCR analysis and negative for quagga/zebra mussels.

Pyramid Lake

August 28, 2025 – adult golden mussels were discovered in Pyramid Lake, Los Angeles County, attached to settlement plates located at the William E. Warne Powerplant. Quagga mussels were also attached to the settlement plates. The mussels were genetically identified as golden mussel using PCR analysis. Sequencing results are pending. Quagga mussels were first detected in Pyramid Lake in 2016.

For a map of all confirmed detections of invasive mussels visit:

• Golden mussel map
• Quagga/zebra mussel map (PDF)

The California Department of Fish and Wildlife Invasive Species Program is forwarding the following notice from the Pacific States Marine Fisheries Commission

2025-2026 WID Training Announcement

We are pleased to share the upcoming schedule for virtual watercraft inspection and decontamination (WID) classes. There is no cost to attend but registration is required. Click on the dates below to sign up. Once registered, more information will be sent to you via email.

Level 1 or 2 (Inspection and Decontamination) Classes:

• September 4 – 5, 2025
• September 30 – October 2, 2025
• November 4 – 6, 2025
• December 9 – 11, 2025
• January 13 – 15, 2026
• February 10 – 12, 2026
• March 10 – 12, 2026
• April 14 – 16, 2026
• May 5 – 7, 2026

For more information, please visit the WID Training Website.
Questions? Please contact Elizabeth Brown at elizabeth@widtraining.com.

This message is being forwarded on behalf of the US Fish and Wildlife Service:

The 2025 Funding Opportunity for Golden Mussel Prevention and Control in the Western United States has officially been posted. The total funding amount for projects is $500,000. There has been significant change in the application process over the past three years, resulting from our transition to GrantSolutions.gov. This opportunity will be open for application through October 6, 2025.

Applications will need to be submitted through grantsolutions.gov, and you will need to create a login and password to access the system. There are recipient tutorials online linked below. Below are the steps you will need to take to access and locate the funding announcement. The funding announcement number is F25AS00320 and the full title is "FY2025 Golden Mussel Prevention and Control in the Western United States"

Please disseminate this opportunity to all interested parties. Please feel free to reach out to barak_shemai@fws.gov or cesar_blanco@fws.gov. The opportunity and instructions can also be found at grants.gov but applications may NOT be submitted through grants.gov. The grants.gov announcement can be found here 2025 Golden Mussel Grant Announcement.

Please follow these Instructions after creating a GRANTSOLUTIONS.GOV login and password.

• Sign into grantsolutions.gov
• Go to the Funding Opportunities page
• Once there use CTRL + F to search the name of the opportunity "name in full" or "Golden Mussel"
• You should see the QZAP opportunity - Select Apply on the far right

Links to the recipient training videos:

• https://www.doi.gov/grants/grantsolutions
• GS Recipient Training Videos, https://home.grantsolutions.gov/home/recipient-training-videos/

Link to general information:

• FWS GrantSolutions https://doimspp.sharepoint.com/sites/fws-FF09W00000/SitePages/GrantSolutions.aspx

Do not submit application through Grants.gov