CDFW News

California Takes Action to Halt Golden Mussel Invasion

Wed, 16 Apr 2025 12:35:36 GMT

In response to the recent detection of golden mussel (Limnoperna fortunei) in the Sacramento-San Joaquin Delta, the state of California has developed a comprehensive Golden Mussel Response Framework to address this urgent invasive species threat. The discovery in October 2024 marked the first known occurrence of golden mussel in North America. To combat this threat, the framework provides coordinated strategies by multiple California departments to prevent further introduction and spread of golden mussels, as well as to contain and suppress infestations to minimize their impact on the environment, water conveyance, recreation and agriculture.

In addition, the California Department of Fish and Wildlife (CDFW) is offering $1 million in grant funding to boating facility operators to enhance efforts against invasive mussels, particularly the threat of golden mussels. This funding supports projects that help prevent the introduction and spread of invasive mussels in lakes, reservoirs and waterways, ensuring the long-term health of state waters. The grant solicitation and application link can be found on CDFW’s website.

Native to East and Southeast Asia, golden mussels pose a significant threat to California’s natural ecosystems, water infrastructure, agriculture, and economy. The invasive species has already caused major disruptions in other parts of the world, including heavy biofouling of water intake systems, and negative impacts to habitat and wildlife.

“The discovery of golden mussels in California is a serious challenge that requires coordinated action and a long-term commitment,” said CDFW Director Charlton H. Bonham. “This response framework recommends critical steps that must be taken across state, regional and local levels to limit the spread and mitigate the impacts of this invasive species.”

“Taking coordinated action to address this invasive species will help safeguard critical water infrastructure like the State Water Project from the negative impacts golden mussels can pose to water delivery systems,” said John Yarbrough, DWR Deputy Director for the State Water Project. “Using this new framework and close collaboration with partner agencies, DWR will implement strategies to address this invasive species and minimize impacts by monitoring for the mussels in SWP waters and developing a mitigation plan.”

Reservoir managers across the state are adjusting their recreational plans for the upcoming boating season to address concerns for the golden mussel.

“Recreational boating is a significant contributor to California’s economy, and California State Parks’ Division of Boating and Waterways (DBW) is working diligently with allied industry and agency partners to provide outreach and educational information to boaters and waterbody managers on the importance of the Clean, Drain and Dry message to help protect the state’s waterways from invasive species,” said DBW Deputy Director Ramona Fernandez. “DBW recommends boaters contact the waterbody manager to learn of any updated requirements before they head out.”

DBW maintains a list of contacts at: https://dbw.parks.ca.gov/inspections.

The response framework developed by the Golden Mussel Task Force is composed of key state and federal agencies, including CDFW, DWR, California State Parks, California Department of Food and Agriculture, and several other federal and local partners. It outlines a comprehensive strategy to respond to the invasive species, focusing on preventing further introduction, containing mussels within currently infested waters and reducing population within the invaded range where feasible.

Key recommendations in the response framework include:

Containment and Prevention Measures
- Development of a map of Delta launch sites to prioritize management at high-use sites.
- Investigation of pathways of spread, such as watercraft and overland movement, aquaculture trade, etc.
- Increased inspection and decontamination capacity for watercraft, with expanded training for inspectors.
Education and Outreach
- Launch of education campaigns to inform the public about the golden mussel threat and how they can help prevent its spread.
- Posting of signage at waterbodies where golden mussels are present promoting the “Clean, Drain, Dry” practice following and ending every outing.
- Collaboration with businesses that provide watercraft cleaning services to promote industry standards.
Incentives and Partnerships
- Promotion of watercraft cleaning services within and around the Delta to assist in controlling the spread of the mussels.

The Golden Mussel Task Force will continue to collaborate to mitigate the impacts of this invasive species and protect the state’s water resources. The Golden Mussel Framework is a dynamic document, evolving with new information and adaptive management strategies.

For more information or to learn how you can help prevent the spread of golden mussel and report sightings visit: https://wildlife.ca.gov/Conservation/Invasives/Species/Golden-Mussel.

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Media Contacts:
Krysten Kellum, CDFW Communications, (916) 825-7120
Maggie Macias, DWR Public Affairs Office, (916) 902-7405
Adeline Yee, California State Parks, Newsroom@parks.ca.gov

1.53 Million Inland Salmon Released to Enhance Recreational Fishing

Fri, 16 Aug 2024 09:55:32 GMT

As part of the California Department of Fish and Wildlife (CDFW) Hatchery Program’s mission to support fish conservation, angling opportunities and California’s economy, CDFW stocked 1.53 million inland Chinook and Kokanee salmon fingerlings into reservoirs in 17 counties this spring.

Over 992,000 inland Chinook salmon were planted across 13 reservoirs in northern and central California ranging from Trinity Lake in Trinity County to Pine Flat Reservoir in Fresno County.

Another 538,000 Kokanee salmon were stocked in 13 reservoirs that include Shasta Reservoir to the north and Shaver Lake in Fresno County to the south.

These stocked inland salmon support popular sport fisheries and occupy a unique ecological niche, thriving in the deep, cold-water environments these reservoirs offer. They are different from anadromous salmon because they do not migrate to the ocean, and instead rear in the reservoirs where released.

Fish are planted at 2 to 3 inches in size and are intended to be “put-and-grow” fisheries that sustain recreational fishing in future years. Stocking fish when they are younger and smaller allows them to feed on natural prey and grow in an open environment. Successful put-and-grow fisheries such as inland salmon allow the hatcheries to significantly increase the total number of fish that can be grown and stocked in a given year as well as the number of waters that can be stocked. These landlocked salmon are too small to be hooked by most anglers’ gear but will reach catchable size in two to three years.

“These fish provide an excellent recreational opportunity with Chinook caught from lakes such as Berryessa and Folsom recently approaching 10 pounds,” said Jason Julienne, a Senior Environmental Scientist Supervisor who oversees CDFW’s Sacramento Valley salmon hatcheries.

The state record inland Chinook salmon was caught at Trinity Lake in 2013 and weighed 20 pounds, 15 ounces. The state record Kokanee salmon was caught in Lake Tahoe in 2013 and weighed 5 pounds, 2 ounces.

All inland Chinook salmon released are “triploids,” or sterile and incapable of reproducing to protect naturally reproducing salmon populations downstream of the reservoirs. The inland Chinook salmon are produced from Chinook salmon eggs collected during spawning operations at the Feather River Fish Hatchery in Oroville.

Kokanee salmon are the landlocked version of Sockeye salmon native to the Pacific Northwest. CDFW’s stocked Kokanee salmon are the offspring of Kokanee salmon eggs collected and fertilized from fish migrating from Stampede Reservoir in Nevada County to spawn into the Little Truckee River. These fish are stocked as “diploids,” meaning they are capable of natural reproduction. Several reservoirs such as New Bullards Bar Reservoir in Yuba County and Whiskeytown in Shasta County support natural reproduction of Kokanee salmon. Other waters such as Bucks Lake in Plumas County and Trinity Lake in Trinity County no longer receive Kokanee salmon plants because their self-sustaining populations are sufficient enough to support fisheries without the need for additional stocking.

As Kokanee salmon typically require cold, snowmelt-fed tributaries to spawn successfully, there is little risk of Kokanee successfully reproducing outside of these large reservoir environments and establishing runs in anadromous waters occupied by native salmon and steelhead.

Anglers are reminded to check the 2024-2025 California Freshwater Sport Fishing Regulations (PDF) for the landlocked salmon daily bag and possession limits at the waters they intend to fish. Most waters have a five-fish daily bag limit and a 10-fish possession limit. However, certain waters, including Bucks Lake in Plumas County, New Bullards Bar Reservoir in Yuba County, Pardee Lake in Amador County and Trinity Lake in Trinity County have a daily bag limit of 10 landlocked salmon with a possession limit of 20. Landlocked salmon bag and possession limits are separate from trout possession limits.

Waters That Received Inland Chinook Salmon in Spring 2024

Shasta Reservoir (Shasta County)
Trinity Lake (Trinity County)
Lake Oroville (Butte County)
Folsom Lake (Sacramento/Placer/El Dorado counties)
Lake Almanor (Plumas County)
Spaulding Reservoir (Nevada County)
Lake Berryessa (Napa County)
Don Pedro Reservoir (Tuolumne County
McClure Reservoir (Mariposa County)
Pine Flat Reservoir (Fresno County)

Waters That Received Inland Kokanee Salmon in Spring 2024

Shasta Reservoir (Shasta County)
Whiskeytown Lake (Shasta County)
Boca Reservoir (Nevada County)
New Bullards Bar Reservoir (Yuba County)
Hellhole Reservoir (Placer County)
Little Grass Valley Reservoir (Plumas County)
Pardee Reservoir (Amador County)
Stampede Reservoir (Sierra County)
Union Valley Reservoir (El Dorado County)
Lake Berryessa (Napa County)
Bass Lake (Madera County)
Don Pedro Reservoir (Tuolumne County)
McClure Reservoir (Mariposa County)
New Melones Reservoir (Calaveras/Tuolumne counties)
Shaver Lake (Fresno County)

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Media Contacts:
Jason Julienne, CDFW North Central Region, (916) 496-4985
Krysten Kellum, CDFW Communications, (916) 825-7120