Pacific Herring are found throughout the coastal zone from northern Baja California on the North American coast, around the rim of the North Pacific Basin to Korea on the Asian coast. In California, Herring are found offshore during the spring and summer months foraging in the open ocean. The largest spawning aggregations in California occur in San Francisco and Tomales Bays. Beginning as early as October and continuing as late as April, schools of adult herring migrate inshore to bays and estuaries to spawn. Schools first appear in the deep water channels of bays, where they can stay for up to two weeks as their gonads mature, they then move into shallow areas to spawn. Most spawning areas are characterized as having reduced salinity with calm and protected waters. Spawning-substrate such as marine vegetation or rocky intertidal areas are preferred but man-made structures such as pier pilings and riprap are also frequently used spawning substrates in San Francisco Bay.
Fishery Management and Research
The Department of Fish and Wildlife has managed the commercial Pacific Herring sac-roe fishery in California since the first opening in 1972. The Department’s biological and enforcement staff have worked closely with the fishing industry throughout this period to provide for a sustainable and orderly fishery.
The Department has conducted surveys of spawning Herring populations as part of its ongoing monitoring and management of the fishery since the 1970’s. The Department documents the occurrence of spawns, and collects data on location, area, substrates used, and the biomass of the adult population. The Department also examines the age structure of the spawning population, growth and general condition, biological aspects of the commercial catch, as well as ocean and estuarine conditions. Assessments of the herring spawning population are then used to provide an estimated “spawning biomass” for a specific spawning area.
The Department conducts these types of annual spawning biomass surveys in San Francisco which serve as the basis for establishing fishing quotas. Quotas in in Tomales Bay, Humboldt Bay and Crescent City are fixed based on historical assessments and landings, with no commercial fishing effort in these areas since 2007, 2005 and 2002 respectively. The Department has developed a state-wide Fishery Management Plan for Pacific Herring (Herring FMP) which addresses current management needs and opportunities for future research.
For information on the management of the Herring Fishery in California or to report a Herring spawn, please email AskMarine@wildlife.ca.gov.