State offers $6 million grant to stem golden mussel spread from Delta

The California Department of Fish and Wildlife is offering $6 million in grant funding to create or enhance boating control efforts in the Sacramento-San Joaquin Delta to slow or stop the spread of invasive golden mussels.

The department will hold a webinar to go over grant details on Nov. 18 at 10 a.m. Grants and all supporting documents must be submitted on Dec. 15 by 4 p.m., according to a notice on the department’s website.

Some basics of what the grant may fund include:
• One-time start-up costs for efforts to prevent the overland spread of golden mussels from the Delta where they have been detected. 
• Projects may include rapid decontamination systems, boat submersion systems, mobile hot water watercraft/equipment decontamination units, and stationary watercraft/equipment decontamination stations. 
• Projects must be on or centrally located to Delta waterways and support the five Delta counties (Yolo, Sacramento, Solano, Contra Costa, and San Joaquin). 
• Fundable costs include, but are not limited to, equipment and supplies, site development and installation, and watercraft inspection training and equipment. 

Golden mussels were first detected in the Delta in 2024, likely carried here in ballast water illegally dumped into the Delta by cargo ships. They have rapidly gained a foothold in water systems throughout the state, all the way to San Diego. Kern County agricultural water districts, which take Delta exports via the California Aqueduct, have been especially hard hit starting in the fall of 2025.

The tiny mollusks have proved more difficult to control than other types of invasive mussels as they can withstand wider temperature ranges and levels of water quality. Their small size has also allowed them to infiltrate even small systems, including golf course watering equipment. They reproduce multiple times per year, allowing them to quickly build into large colonies, clogging pipes and wrecking equipment within months.

For more information on the grant opportunity, prospective applicants may contact CDFW at invasives@wildlife.ca.gov.