Emergency Action to Readopt the Amendment of Section 671, Title 14, CCR, Re: Golden Mussel

2025050255

California Fish and Game Commission (CDFGC)

NOE - Notice of Exemption

5/7/2025

5/7/2025

Melissa Miller-Henson

California Fish and Game Commission

Executive Director

Lead/Public Agency

PO Box 944209
Sacramento, CA 94244-2090

(916) 653-4899

Melissa.Miller-Henson@fgc.ca.gov

Statewide

Categorical Exemption

California Code of Regulations, Title 14, sections 15307, 15308

At its April 16-17, 2025 meeting, the California Fish and Game Commission (Commission) took final action under the California Fish and Game Code and the California Administrative Procedure Act with respect to the above-named project. In taking its final action for the purposes of the California Environmental Quality Act (CEQA, Public Resources Code, Section 21000 et seq.), the Commission re-adopted an emergency amendment to Section 671, Title 14, California Code of Regulations (CCR), relying on categorical exemption classes 7 and 8 to protect natural resources and the environment (CEQA Guidelines, Title 14, sections 15307 and 15308, CCR). Categorical Exemptions to Protect Natural Resources and the Environment The Commission action retains golden mussel on the list of restricted animals consistent with California Fish and Game Code sections 2118 and 2120. For purposes of CEQA, the Commission re-adopted the amendments to Section 671, Title 14, CCR, relying on the class 7 and 8 categorical exemptions. In general, the exemptions apply to agency actions to protect natural resources and the environment. Class 7 actions include those taken by regulatory agencies to assure the maintenance, restoration, or enhancement of a naturel resource where the regulatory process involves procedures for protection of the environment. Class 8 actions include those taken by regulatory agencies to assure the maintenance, restoration, enhancement, or protection of the environment where the regulatory process involves procedures for the protection of the environment. Golden mussel (Limnoperna fortunei) is an invasive, non-native, freshwater bivalve native to rivers and creeks of China and Southeast Asia. Golden mussel is known to be established outside of its native range in Hong Kong, Japan, Taiwan, Brazil, Uruguay, Paraguay and Argentina, with initial introductions to these countries likely the result of ships from biofouling on the hulls and/or ballast water release. In most cases, the invaded range has expanded upstream from the point of introduction and inland from ports through local, human-mediated pathways. Within the invaded range, significant impacts resulting from the dense colonization of golden mussels on hard surfaces are widely documented. On October 17, 2024, golden mussels were discovered in the Port of Stockton by California Department of Water Resources staff while conducting routine operations. Golden mussels were also detected in O’Neill Forebay on October 25 and at the outlet of the forebay into the California Aqueduct on October 31. O’Neill Forebay is a forebay of San Luis Reservoir, which is a joint use facility of the California State Water Project and federal Central Valley Project located in Merced County. These detections represent the first known occurrence of golden mussels in North America. Additional discoveries of golden mussel have occurred throughout the Sacramento-San Joaquin Delta (Delta) and adjacent regions, including Bethany Reservoir on December 30, 2024, and San Joaquin River on February 24, 2025. The spread of golden mussel out of the Delta into freshwater rivers, lakes, and reservoirs will cause infrastructural damage across the state, and could threaten water delivery and electric power delivery from hydroelectric operations (for example, O’Neill Forebay). Because of rapid mussel colonization of infrastructure and water conveyances, this new invasion is a significant threat to the ecological health of the Delta and all waters of the state, water conveyance systems, infrastructure and water quality. Golden mussel has a similar appearance, biology, and impact as quagga and zebra (dreissenid) mussels. Dreissenid mussel infestations resulted in the temporary and permanent closure of waterbodies to the public and have negatively affected aquatic ecosystems. Golden mussel can tolerate a wider range of environmental conditions than dreissenid mussels, including less calcium, higher salinity, and warmer water temperatures. Nearly all waters of California, including the brackish parts of estuaries, such as Suisun Bay, are conducive to golden mussel establishment. Like dreissenid mussels, golden mussel poses an environmental threat to California since it is an ecosystem engineer and can profoundly change the food web of an invaded ecosystem. Golden mussel can impact native species and sport fish by competing for food sources, and can also increase water clarity due to intense filter feeding, resulting in degraded water quality, algal blooms, and increased aquatic vegetation growth that requires control to maintain navigation. Protection of the Environment Golden mussel poses a significant immediate threat to the state’s environment, ecological health of the Delta and all waters of the state, and water quality. The species’ presence in California is of statewide, national, and international concern. Without actions to prevent further spread, golden mussel is also likely to spread overland on trailered watercraft and equipment to other fresh and brackish waterbodies throughout California, to other ports and inland waters of North America, and even potentially abroad. Immediate steps are necessary to stop the spread of this prolific invasive species to prevent translocation to other waterbodies in the state and beyond. If spread of this species is not prevented, more waterways will be infested, further increasing the threat to uninfested waters. The re-adopted emergency regulation retains golden mussel on California’s list of restricted animals in Section 671, Title 14, CCR; this will continue the prohibition to transport, possess, and import live golden mussels in California, thereby deterring people from moving them to other waters of the state and providing enforceability if golden mussels are found in someone’s possession. Including golden mussel on the list of restricted species allows water managers already operating mussel prevention programs, the grounds to refuse vessels and equipment that are or suspected to be carrying golden mussels from launching into lakes, reservoirs, or other waterways where golden mussels are not known to be present. Additionally, it allows law enforcement personnel to inspect watercraft and quarantine any vessels that are infested with golden mussels and/or detain vessels or equipment until such time as they no longer pose a threat. Including golden mussel on the list of restricted species supports class 7 and 8 exemptions toward the maintenance and preservation of the ecological health of the Delta and freshwater rivers, lakes and reservoirs, as well as the systems in place for public health and safety as noted above. The project (adding golden mussel to Section 671, Title 14, CCR) will assist with protecting natural resources and the environment and, thus, is the proper subject of CEQA’s Class 7 and Class 8 categorical exemptions.