Invasive Mussel News

The following is being sent on behalf of the California Natural Resources Agency

California Natural Resources Agency Hosts Discussion on California’s Growing Invasive Species Threat

From golden mussels clogging waterways to invasive weeds fueling wildfires and pests threatening agriculture, invasive species pose a growing threat across California. Their impacts reach far beyond the environment, affecting water supplies, infrastructure, recreation, agriculture, and native wildlife. Join us to learn why this threat is growing and how California is responding through early detection, prevention, and coordinated management to protect our state in coming years.  

Register to Join

What: Secretary Speaker Series: Uninvited Guests: Protecting California from Invasive Species 

When: Thursday, August 20 from noon to 1pm (PDT)

The following is being sent on behalf of the Western Regional Panel on ANS

Join us for the 2026 Annual Meeting in Sacramento, CA. Our theme “Sustaining Successful Aquatic Invasive Species Management” will drive the meeting content. The meeting is hosted by California Department of Fish and Wildlife. Please check the meeting’s page frequently as new information will be posted as it becomes available.

The current draft agenda is now available . The agenda is still subject to change, and the most current agenda will be updated. 

Reserve Your Hotel Room

Reserve your room! The Holiday Inn Sacramento Downtown-Arena is offering a special rate of $149 plus tax for our meeting. The room block will be available until August 26. To take advantage of this special meeting rate.

Conference Registration

Registration for the annual meeting comes at no cost to you. Generous sponsors support meeting expenses like quality AV services and refreshments help make this possible.

• Register for the September 23-24 Conference
• Register for the September 25 Field Trip (Limited to 50 participants)

Virtual Participation

Virtual participation for the 2026 Annual Meeting will be limited. The WRP will have a virtual platform to join the meeting, however there will be limited ability to interact with the speakers and audience. We encourage you to participate in person. If you have any questions or comments regarding virtual participation – please reach out. Complete the registration process and indicate that you will be attending virtually.

Questions

Please contact Leah Elwell with any questions via email.

The California Department of Fish and Wildlife has published the Notice of Proposed Action to amend sections 650, 672, 672.1, and 672.2 to Title 14, California Code of Regulations (CCR). Fish and Game Code Section 2301 authorizes the Department to adopt regulations regarding the management of invasive mussels. The Department will hold a virtual public hearing for this proposed action on Tuesday, August 18, 2026, from 1:00PM to 2:00PM.

Zoom Teleconference/Webinar

Any interested person, or their authorized representative, may submit written comments on the proposed action to the Department. All written comments must be received by the Department via mail or email no later than Tuesday August 18, 2026, to the contact as follows:

California Department of Fish and Wildlife
Regulations Unit
Attn: Daphne Nandino, Analyst
P.O. Box 944209
Sacramento, CA 94244-2090
Email: Regulations@wildlife.ca.gov

Visit Regulation Unit - Invasive Mussel page for proposed action.

The following information is being sent on behalf of the Invasive Species Council and California Department of Food and Agriculture

SACRAMENTO, July 3, 2026 – The California Department of Food and Agriculture and the California Natural Resources Agency are seeking nominations for two qualified individuals to serve on the California Invasive Species Advisory Committee (CISAC).

The CISAC is tasked with providing advice to the Invasive Species Council of California (ISCC) on a broad array of issues related to preventing the introduction of invasive species and providing for their control and/or eradication, as well as minimizing the economic, ecological, and human health impacts that invasive species cause. CISAC members should anticipate meeting at least once quarterly each year but may be required to meet more regularly in some circumstances.

The ISCC represents the highest level of leadership and authority in state government regarding invasive species. Its goal is to promote a consistent approach to invasive species at the state level. The ISCC is co-chaired by the Secretary of the California Department of Food and Agriculture and the Secretary of the California Natural Resources Agency. Other members include the secretaries from the following California agencies:

• Environmental Protection Agency
• State Transportation Agency
• Health and Human Services Agency
• Governor’s Office of Emergency Services

Prospective nominees of the CISAC should be knowledgeable in and represent one or more of the following communities of interest:

• Biology, Ranchers, Foresters, Farmers, Academics / Researchers, Public Health Specialists, Weed Science, Nematology, Veterinary Medicine, Industry Representatives, Educators, Tribal Government Representatives, Information / Database Managers, Economists, Risk Assessment Analysts, Entomology, Plant Pathology, Public Health / Epidemiology, Federal Government Representatives, County Agricultural Commissioner Representatives, Invasive Species Management Specialists, Persons involved with Global Commerce, Non-Governmental Environmental Representatives, Expertise in Climate Change and Ecosystems, Public Relations Specialists, Lawyers specializing in Invasive Species Policy, Public Member

Members will be selected in order to achieve a balanced representation of viewpoints, so to effectively address invasive species issues under consideration. Membership terms are three years, and no member may serve on the CISAC for more than two consecutive terms.

Members of the CISAC and its subcommittees will serve without pay. However, while away from their homes or regular places of business in the performance of services of the CISAC, members, to the extent funding is available, may be allowed travel expenses, including per diem in lieu of subsistence.

Submitting Nominations:

Nominations should be typed and should include the following:

1. A brief summary of no more than two pages explaining the nominee’s suitability to serve on the CISAC.
2. A resume or curriculum vitae.
3. At least two letters of reference.

Nominations should be postmarked no later than Tuesday, July 28, 2026, to the following address:

Invasive Species Council of California
Executive Office
1220 N Street, Suite 221
Sacramento, California 95814

For additional information, visit the Invasive Species Council of California’s website at: www.iscc.ca.gov

The California Department of Fish and Wildlife (CDFW)'s Invasive Mussel Control Plan Guidance document is intended to provide guidance on developing an invasive mussel control plan (Control Plan) to public and private agencies that operate a water supply system where invasive mussels have been detected. The Control Plan Template (Appendix A) is offered as a tool to assist water supply system agencies, and others, in developing a Control Plan that complies with the requirements under Fish and Game Code Section 2301 and California Code of Regulations, Title 14, Section 672 and 672.1. Use of the template, while recommended, is not required for compliance.

The guidance is available on CDFW's Quagga/Zebra Mussel webpage under the heading Invasive Mussel Control Plan Development and on the Golden Mussel webpage under the heading Additional Information, Waterbody Managers.

CDFW staff are available to assist throughout the development of a Control Plan. Please contact the CDFW Invasive Mussel Regional Scientist (PDF) based on the CDFW Region where the water supply system is located. If the water supply system spans multiple CDFW regions contact invasive@wildlife.ca.gov for assistance.

CDFW News | CDFW Confirms Northernmost Detection of Golden Mussel in Port of West Sacramento

The California Department of Fish and Wildlife (CDFW) is notifying the public and officials with the city of West Sacramento and Yolo and Sacramento counties that invasive golden mussels have been found in and around the Port of West Sacramento. 

This is the northernmost detection of golden mussel since the species was discovered in the Port of Stockton in the Sacramento-San Joaquin Delta in 2024. 

CDFW staff monitoring for golden mussel presence collected one mussel between the Jefferson Boulevard overpass and the west lock, and a second near the intersection of Boathouse Road and Stone Boulevard. The mussels were sent to CDFW’s genetics lab that confirmed on June 25 the specimens were golden mussel. Additional surveys around the docks in Washington Lake found additional mussels.  

It is believed the golden mussels found in the Port of West Sacramento are from a source population within the vicinity. Golden mussels are harmful to aquatic ecosystems, water conveyance systems and water infrastructure. 

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. Golden mussels attach to almost any underwater surface, including but not limited to boats, ropes, buoys and aquatic plants that entangle on anchors and trailers. 

Clean, Drain, Dry — inspect your watercraft, kayak, life vests, paddles and anything that touched the water every time it is removed from a water body. Remove all debris, animals, and plants, and dispose of them in the trash. Drain all water from ballasts, bilges and live wells. Lastly, allow everything to dry until moisture is no longer present. 

Through the continued efforts by boaters and others recreating on California’s waters, golden mussel can be prevented from spreading to waters not connected to the Delta. 

Help CDFW monitor the state’s waters for golden mussel by reporting organisms suspected to be golden mussel to CDFW’s Invasive Species Program. Include the specific location of the observation, at least one clear close-up photograph of the organism and your contact information. 

Submit reports via one of the following options: 

• Online at Report Golden Mussel
• Via email to invasives@wildlife.ca.gov
• Via telephone to (866) 440-9530

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Media Contact:  
Krysten Kellum, CDFW Communications, (916) 825-7120 

The following information is being sent on behalf of the Invasive Species Council and California Department of Food and Agriculture

Proposition 4 Funding

In November 2024, California voters approved Proposition 4, a $10 billion Climate Bond designed to safeguard communities and natural resources from climate change. The Bond allocated $20 million for Invasive Species Grants. The California Department of Food and Agriculture (CDFA) on behalf of the Invasive Species Council of California (ISCC) will implement these programs. In 2026, ISCC plans to release a solicitation for the Invasive Species Grant (ISG) Program. The Bond requires CDFA to solicit public feedback on the program solicitation guidelines. We look forward to your partnership in shaping these programs.

Public Comment Period

The public comment period for the ISG Draft Application Guidelines will be open from April 29 to May 29, 2026.

• Application Guidelines (Draft)
• Cover Page and Narrative
• Budget and Budget Narrative

Comments can be submitted at cisac@iscc.ca.gov or in writing to:

Victoria Hornbaker
Plant Health and Pest Prevention Services
California Department of Food and Agriculture
1220 N Street Sacramento, CA 95814

Estimated initial ISCC ISG Solicitation Timeline

Timelines are provided for planning purposes and are subject to change.

• Proposal Opens: July 2026
• Proposal Close: August 2026
• Award Notification: November 2026
• Award Execution: February 2027

CDFW will no longer send notifications of new invasive mussel detections, include golden mussel, quagga mussel, and zebra mussels, discovered in hydrologically connected waters via this listserv. To continue to receive notifications of new detections, please register with the USGS’s Nonindigenous Aquatic Species Alert System. Please be sure to sign up for bonus alerts to receive every new detection.

CDFW will continue to maintain maps of all invasive mussel detections at:

• Golden mussel map
• Quagga/zebra mussel map

The following information is being forwarded on behalf of California Natural Resources Agency and Department of Water Resources

The California Department of Water Resources (DWR) is modifying its inspection program for invasive mussels at Lake Oroville, the Thermalito Forebay, and the Thermalito Afterbay. Effective today, April 29, watercraft inspections, decontamination services, and seal checking at the Oroville facilities are no longer required. Blue Oroville seals are no longer required to launch watercraft and owners have permission to remove seals themselves, as inspectors will no longer be stationed at launch ramps. DWR will also reopen facilities that were closed to trailered launching including those at the Thermalito Forebay and Thermalito Afterbay. At locations requiring the removal of physical barriers, additional time will be required for crews to fully reopen facilities. Launching access at Lake Oroville will once again be available 24 hours a day, every day.

The decision to implement an invasive mussel boat inspection program at DWR’s Oroville facilities in May 2025 was based on available information about how best to protect DWR infrastructure from golden mussel establishment. While DWR does not control many of the lakes and reservoirs upstream of Lake Oroville, it quickly established a program to reduce the potential risk of invasive mussel introduction through recreational boating. Additional analyses of golden mussel biology and habitat requirements, as well as an assessment of DWR’s Oroville infrastructure, have shown a lower risk of golden mussel establishment than was originally anticipated.

During the last year, DWR performed a vulnerability review of Lake Oroville, the Upper Feather River Lakes, the Feather River Fish Hatchery, and Oroville-Thermalito Complex infrastructure to golden mussel colonization. The seasonal water temperature conditions at Lake Oroville and the Upper Feather River Lakes were evaluated based on a 2017 study in which researchers assessed the conditions golden mussels need to survive and reproduce.

For golden mussel maturation and reproduction to occur, water temperatures greater than 61.7°F for about 150 days are necessary for successful spawning and the formation of veligers, the larval stage of mussels. For veligers to complete their development and settle into a hard-shell mussel, water temperatures must be nearly 70°F for approximately 70 days.

Temperature thresholds for golden mussel maturation exist within the top 60 feet of Lake Oroville, meaning that sustained mussel populations would be confined to specific areas of the reservoir, such as floating infrastructure, and boats that remain on the water for lengthy periods. Mussels could survive in shallow shoreline locations until lake levels drop, at which point they would dry out and die. Extended cold water temperatures in the Upper Feather River lakes, the depth of Lake Oroville, and the continuous cold water releases from Oroville Dam to support salmon habitat are limiting factors for golden mussel spawning and larval development. Any veligers that are transported through the dam at lower lake elevation temperatures would be unlikely to survive, would have a difficult time growing, and would not have a significant impact on the Feather River Fish Hatchery and Oroville-Thermalito Complex powerplants.

Given this analysis of potential impacts to State Water Project infrastructure, DWR is no longer requiring watercraft inspections at Oroville. Ongoing water testing and visual inspections of infrastructure for invasive mussels will continue. Golden mussels have not been detected at DWR’s Oroville facilities or the Upper Feather River lakes. Program changes are being coordinated with local recreation partners at the California Department of Parks and Recreation and the California Department of Fish and Wildlife.

DWR continues to partner with federal, State, and local agencies to mitigate golden mussel colonization throughout California’s water systems. This includes coordinating with partners on a statewide reporting system for watercraft, continued public education campaigns about golden mussels and how they spread, ongoing studies about effective treatment options, and implementing a variety of mitigation and maintenance actions to maintain State Water Project operations that are currently affected by the presence of golden mussels.

When recreating on California’s waterways, always remember to:

• Clean aquatic plants and animal material from your boat, trailer, and equipment before leaving the ramp or parking lot.
• Drain ballast, bilge, live-wells, and other water-containing devices, and never drain back into the waterway.
• Dry equipment, including bilge, ballast tanks, and live well, before launching into another body of water.

More details about DWR’s invasive mussel inspection program are available at water.ca.gov/mussels.

The following information is being forwarded on behalf of the Oregon Department of Fish and Wildlife

SALEM, Ore. – ODFW staff at the Ashland Boat Inspection Station found golden mussels on a watercraft that was being transported to a new owner from the Sacramento River Delta to Oregon on April 4. The watercraft was decontaminated at the inspection station and all golden mussels attached to the boat were properly disposed.

This is the first detection of adult golden mussels being transported into Oregon. Golden mussels were detected for the first time in North America in 2024 and the threat to Oregon is very serious.

Golden mussels are similar to zebra or quagga mussels, but they can establish in a much wider range of temperatures and can tolerate some water salinity. They feed heavily on microscopic aquatic plants and animals that are essential food sources for native species and sport fish.

Invasive freshwater mussels can damage water infrastructure, such as irrigation and hydropower systems, and also degrade water quality and limit recreational activities such as fishing and boating.

"Early detection like this shows how critical watercraft inspections are to protecting our fisheries, infrastructure, and agriculture," said ODFW Invasive Species Coordinator Keith DeHart. "We are grateful for the boat owner's cooperation throughout the inspection and decontamination process. Their willingness to follow regulations and assist staff played an important role in helping prevent the potential spread of invasive mussels into Oregon's waters."

It is the law in Oregon that any vehicle transporting a watercraft is required to stop at any open watercraft inspection stations for aquatic invasive species inspections.

Watercraft owners should be aware of where inspections stations are located around Oregon. Stations are open if orange, "Boat Inspection Ahead," signs are posted, followed by "Inspection Required for All Watercraft."

Visit MyODFW.com for more information about the Aquatic Invasive Species Prevention Program and Waterway Access permits.

ODFW, in partnership with the Center for Lakes and Reservoirs at Portland State University, has not detected invasive freshwater mussels in any of Oregon's waterways thanks to responsible boaters and inspection station crews. However, Oregon is still at risk of an invasion. In 2025 crews decontaminated 12 watercraft carrying invasive freshwater mussels and intercepted an additional 295 watercraft for other types of aquatic biofouling such as Eurasian Watermilfoil.

Since the start of the Watercraft Inspection Stations program in 2010, ODFW has inspected 246,748 watercraft and intercepted 185 watercraft with invasive freshwater mussels and 3,758 watercraft with other types of aquatic biofouling.

Last month, quagga mussels were found on a watercraft entering Oregon, the first confirmed instance in 2026 of invasive freshwater mussels being detected on a boat entering the state.

Inspection station locations and operating hours:

Ashland: I-5 at the Ashland Port of Entry. Open daily, year-round, during daylight hours.

Ontario: I-84 at the Ontario Rest Area. Open daily, year-round, during daylight hours.

Seasonal inspection stations located in Brookings, Klamath Falls, Umatilla, and at Owyhee Reservoir will be opening the first week of May. ODFW will also have roving inspection crews working boat ramps and other access points around the state this year.

If you find invasive freshwater mussels on a vessel, please help protect Oregon and report them to the Oregon Invasive Species hotline by calling 1-866-INVADER or visiting https://oregoninvasiveshotline.org.