The Pacific Sardine
In our first installment in a series of fisheries “classics”, we discuss the Pacific sardine (Sardinops sagax). The US west coast sardine fishery made headlines last year when the Pacific Fishery Management Council completely closed the commercial fishing seasons for Washington, Oregon and California. The sardine fishery has been quite important in understanding the biology of exploited fishes and is justly deserving of being our first “classic” fisheries story.
History of abundance, catch and fishing mortality
Pacific sardines once supported the largest fishery in the California current, off the west coast of North America from Canada to Baja California. The fishery developed at the beginning of the Great Depression as Pacific sardines were processed for food and oil as well as for fish meal used by the expanding poultry industry. At its peak, the fishery yielded an average of 600,000mt annually, topping out at over 700,000mt in 1936-37. Cannery Row, in Monterey, CA (made famous by John Steinbeck’s novel of the same name) was named for the sardine processors that lined the main street.
In the 1950s, the stock collapsed—culminating in a California-legislated moratorium on commercial sardine harvests from 1967-1986, closing even the small bait fishery (Figure 1).
This collapse first led the scientific community to believe that overfishing was the root cause of the problem, but would later realize that environmental conditions mainly dictate abundance. With the collapse of Sardinops sagax, by 1972 fishing effort in the California current had shifted to northern anchovies (Engraulis mordax), which had become abundant.
Through the 1980’s and 1990’s Pacific sardine abundance began to recover. This period was marked by a notable El Nino year in 1992 when Pacific sardines were dispersed as far north as British Columbia where they had not been seen in over 40 years. In the early 2000’s Pacific sardine biomass levels reached 1 million mt, but with a series of poor recruitments declined to the low levels reported last year.
See Figures 2, 3, and 4 for biomass, catch and total allowable catch (TAC), and fishing mortality rate of Pacific sardines.
History of science, management and fishing fleet
During most of the 20th century, the Pacific sardine fishery was managed by the California Department of Fish and Game (CDFG). In response to the puzzling scientific issues raised by the 1950’s collapse, the fishing industry adopted a self-imposed tax and underwrote the creation of a new multiagency scientific program, the California Cooperative Oceanic Fisheries Investigations (CalCOFI), an entity that still exists today. When the Pacific Fishery Management Council (PFMC) was formed in the late 1970’s, sardines were scarce, and the PFMC declined responsibility for managing a nonexistent fishery. With the subsequent re-growth of the stock and reappearance of fishable concentrations off Washington in the 1990’s, the PFMC assumed control of the US fishery under the authority of the Maguson-Stevens Act.
Federally mandated TAC guidelines from the PFMC began in 2000 (Figure 3). CalCOFI has remained an important engine for Pacific sardine research, but NMFS assumed responsibility for annual stock assessments needed by the PFMC.
In the US, the Pacific sardine is currently a limited entry fishery with a total allowable catch (quotas), however the limited entry permit covers all pelagic finfish, not just sardines. There are 65 permit holders out of California with another 40-50 from Oregon and Washington, but it is unclear how many boats target which species. Sardines are typically caught with purse seines, though some vessels are transitioning to drum seines. The historical hubs are still in Southern California and Monterey Bay, but Astoria, Oregon has recently supported a major fishery. About 85% of the catch is processed and shipped to China, Japan and South Korea. The other 15% typically composes the bait fishery. Bycatch is negligible (less than 1%).
In 1965 Garth Murphy conducted a comprehensive study of sardine demography in the California current and concluded that intense fishing effort was the primary cause for the stock’s collapse. It was precipitated by poor recruitment in the early 1950’s, but overfishing was considered the main catalyst. Murphy also suggested that the surging populations of northern anchovy had ecologically replaced Pacific sardines. Specific environmental influences were not identified.
The overfishing paradigm was not comprehensively challenged until 1992 when Soutar and Isaacs (1972) conducted a fish-scale analysis from anaerobic sediment deposits off the coast of Santa Barbara, and found that sardines had naturally disappeared at other times in the past. More detailed analyses by Baumgartner et al (1992) showed a somewhat cyclical pattern for Pacific sardine populations with periods of roughly 50 years (Figure 5).
The cause of these cycles is unclear. The predominant theory is that the productivity changes are due to upwelling cycles and/or changes in oceanic circulation associated with long-term fluctuations in sea surface temperature.
While populations did increase according to Baumgartner et al’s 50-year theory in the 1990’s, they were still well below the high levels of the 1940’s. Similar to patterns of fluctuations seen in the Santa Barbara sediments, Pacific sardine biomass dropped sharply from 1 million mt in 2006 to an estimated 97,000 mt in 2015, causing the abrupt closing of the commercial fishery, in accordance with the biomass-dependent harvest plan
See below for our science and management timeline.
Learn more about sustainable seafood below.