Thank you for reading the Department of Fish and Wildlife Pacific herring blog. Here you will find information on recent spawning activity, including photos and video clips documenting the work of the Department. You can follow the Department staff as they work to complete the annual herring population estimates for San Francisco Bay. In season, there will also be weekly updates on commercial landings by the herring fleet and important information related to the CEQA process and annual changes to regulations that are approved by the Fish and Game Commission. You may also visit our Department of Fish and Wildlife State-Managed California Commercial Herring Fishery web page for more information.
For those that are less familiar with Pacific herring in California and the work of the Department, here is a quick primer to get you started.
Pacific herring (CDFW)
Biology and Life History
Pacific herring (Clupea pallasii) are a small schooling fish found throughout the coastal zone from California around the Pacific Rim to Korea. They are dark blue to olive on their backs, fading to silver on their sides and bellies. They are plankton feeders, primarily feeding on copepods, amphipods, fish larvae, and molluscs. In California herring are found offshore during spring and summer and migrate inshore to bays and estuaries to spawn from November through April. Pacific herring become sexually mature at 2-3 years of age and spawn every year after reaching maturity (up to 8 yrs in SF Bay). Males release milt into the water column to begin fertilization. Females extrude adhesive eggs (up to 20,000) on a variety of substrates including; subtidal vegetation, rocks, pier pilings and rip rap. Herring young-of-the year remain in the bay through the summer before entering the ocean in the early fall.
Commerical herring vessel at Pt San Pablo (CDFW)
The Department has managed the commercial Pacific herring fishery in San Francisco Bay since its inception in 1972. Biological and enforcement staff work closely with the industry to provide for a sustainable fishery. The Department conducts annual surveys of the spawning herring population in San Francisco Bay as part of its ongoing monitoring and management of the fishery. The Department also examines age structure, growth and general condition, biological aspects of the catch, and environmental conditions. These data serve as the basis for establishing fishing quotas for the next season. Regulatory decisions each season are the responsibility of the Fish and Game Commission.
Forage and the Fishery
Herring spawn on eelgrass (CDFW)
Herring are an important forage species for ocean and bay food webs. Herring eggs, larvae, young-of-the-year and adults provide a food source for a variety of birds, mammals, fishes, and invertebrates. The San Francisco Bay population supports a valuable fishery for herring roe, or kazunoko, a traditional Japanese delicacy. A smaller herring-eggs-on-kelp (HEOK) fishery suspends giant kelp from rafts on which herring spawn. The egg-coated kelp blades are brined and exported to Japan (known as komochi or kazunoko kombu). San Francisco Bay also supports a limited commercial fresh fish and recreational fishery. As with most coastal pelagic species, herring populations fluctuate depending on a variety of factors, including food availability, spawning conditions, competition and predation. Many aspects of the commercial fishery also change with time. Over the years the value and participation in the roe fishery has fluctuated, but it appears to have stabilized at a very low level when compared to historical benchmarks. Recently, there has been a renewed interest in a fresh fish market for herring, driven by a desire for a local and sustainable food source. The Department will continue to manage this important fishery, ensuring sustainability and working to help maintain herring’s important role in both ocean and bay ecosystems.