United States West Coast Pacific Sardine Fishery
The Pacific sardine fishery has historically been a productive and lucrative industry along the West Coast of North America. However, climate change and increased fishing pressure have brought turmoil to this fishery resulting in its collapse first in the 1950s and later in 2015. Although the three Pacific sardine populations have oscillated across decades, recent booms have been far less productive and busts all the more devastating. The fishing community has been able to remain profitable by adaptively targeting different species and maintaining high levels of fishing skill within the community. However, the aforementioned impacts have pushed the fishery beyond its natural limits. This case study examines the effectiveness of the existing harvest control rule in light of climate variation, and its likely effectiveness in the face of climate change. Several contextual factors have made the existing harvest control rule – which sets the harvest rate based on the population size and the sea surface temperature, and which includes a biomass threshold – possible, including a high capacity governance system, a science-based and participatory management system, and a broad understanding by stakeholders of the highly variable nature of the stock.
The Pacific sardine (Sardinops sagax) fishery has historically been one of the most abundant fisheries within the California Current Ecosystem (CCE), despite its boom-and-bust cyclical trends (McClatchie et al. 2017). There are three subpopulations of Pacific sardines which can range from Baja California, Mexico, to British Columbia, Canada (Smith et al. 2021). The natural boom and bust cycles of these populations occur on a timeline of 50-60 years and have been linked with trends in the Pacific Decadal Oscillation for hundreds of years (Kvamsdal et al. 2016). Unfortunately, the natural high and low biomass cycles of this fishery have been largely disrupted and influenced by both overfishing and climate change. The fishery first experienced increased fishing pressure in the early 1900s largely driven by the demand for a diversity of new food sources that resulted during World War I (Pacific Fishery Management Council, 2021). As a result, the Pacific sardine fishery became the largest fishery in the western hemisphere. By 1930-1940, Pacific sardines accounted for nearly 25% of the total fish biomass landed in the United States. However, their populations began to decline towards 1940 due to natural oceanic changes and overfishing (Pacific Fishery Management Council, 2021).
Followed by this decline, the fishery experienced a collapse in the 1950s which resulted in strict regulations implemented on the catch of the species. California, which had jurisdiction over the sardine fishery at the time, implemented a moratorium on commercial sardine harvest from 1967-1986 to aid in the recovery of the fishery. Additionally, fishing efforts shifted to focus on anchovies which had since increased in abundance. As a result, the Pacific sardine fishery began to recover during the 1980s-1990s when the Pacific Fishery Management Council (PFMC) assumed management responsibility for the sardine fisheries off California, Oregon, and Washington. Despite this improvement in stock abundance, a series of low recruitment years led to further abundance declines during the 2000’s, resulting in the 2015 fishery closure (Sustainable Fisheries, 2016).
Currently, Pacific sardines are fully managed under the Coastal Pelagic Species Fishery Management Plan (CPSFMP) and are regulated by harvest control rules (HCRs) set on the fishery each year, which determine how much fishing can take place. These HCRs are based on ocean conditions, such as sea surface temperature, and previous stock assessment to determine annual catch limits that attempt to reduce the decline in sardine biomass (Kvamsdal et al. 2016). Various regulatory measures, including a biomass threshold for fishing, catch and seasonal limits, permitting, gear restrictions, and monitoring plans have also been put into place to promote recovery in the fishery and protect the fishery and its stakeholders from another collapse and closure as occurred in 2015 (NOAA Fisheries, 2020). These rules are intended to better conserve and manage the Pacific sardine stock off the U.S. West Coast.
Resilience to Climate and Fishing Impacts
While much of the blame for Pacific sardine demise had been placed on the commercial fishing industry, climatic variation including marine heatwaves (MHW) appear to be impacting the distribution of the species. For example, the 1992 El Nino pushed populations farther north than had been recorded in over 40 years, indicating the clear connection climate-related heating events can have on this fishery (Sustainable Fisheries, 2016). Further research suggests that as the Pacific Ocean warms, some species will move farther north to compensate for the temperature increase in their original regions. Lastly, a recent study predicts that the northern Pacific sardine subpopulation is expected to be driven northward as a result of this warming – reducing the estimated northern sardine stock landings by approximately 20-50% in the next 60 years (Smith et al. 2021).
Despite this shift, researchers suggest that the southern subpopulation may move northward, thus mitigating the impacts of a reduced northern sardine stock in the region (Smith et al. 2021). Additionally, the Pacific sardine fishery has an inherent capacity to withstand ecological change, as evidenced by its survival in the face of El Nino events, changes in the Pacific Decadal Oscillation, variations in upwelling, and more. The existing harvest control rule implemented by the PFMC maps onto this inherent resilience by ensuring there is a reserve population large enough to survive during years when oceanographic conditions are not favorable and to recover when they are, via the biomass threshold provision. However, because this stock is transboundary, the lack of coordinated management (especially between the U.S. and Mexico) is a threat.
Many attributes within the ecological dimension help confer resilience within the Pacific sardine fishery. These attributes include high population abundance during boom (productive) years, intact age structure with a low age at maturity (1-2 years) and long lifespan (up to 15 years), semelparous spawning, and ecosystem connectivity. Conversely, ecological features like high dependence on ocean productivity and environmental forcing and high levels of natural mortality might act to reduce resilience in the fishery. Fishing pressure has also reduced resilience by dramatically decreasing baseline biomass levels from historical unfished and fished levels, removing very young fish (1-3 years), truncating age structure, and likely reducing overall population fecundity.
As mentioned, the Pacific sardine fishery has remained a critical fishery not only along the West Coast, but has made up a large portion of total U.S. catch in previous years. This has impacted the social and economic dimensions of this fishery. From a socio-economic perspective, high levels of fishing skill and learning capacity in the region and the adaptive ability to fish other species in the region or move with the species, has historically improved resilience in this fishery. The adaptive behavior and knowledge diversity of fishermen paired with the species diversity in the region has allowed fishermen to switch targets away from Pacific sardines when necessary without needing to make dramatic changes in vessels or gear, saving time and money in the process. However, low social diversity amongst fishermen, low levels of government transparency and accountability, and low wealth and reserves pose serious threats to the system and will ultimately reduce resilience. The low market power of fishermen relative to buyers places many fishermen at an economic disadvantage. Furthermore, limited trust in the government and high competition between competing fishermen lead to the failure of the fishing community to adopt an ITQ system which could have ultimately benefited the system as a whole if implemented successfully.
Participatory, consensus-driven governance has conferred resilience on this fishery. The fishery currently includes a voting mechanism to make decisions with good leadership and initiative, planning capacity, high scientific capacity, forward looking scientists, harvest control rules with biomass threshold and temperature-sensitive considerations, and the flexibility to shift to other species due to management under a single Coastal Pelagics FMP with no gear endorsements. Although participatory governance can confer resilience, it also retains drawbacks that cause it to limit resilience in the system largely due to the length of time it can take for decision-making to occur under this system and overall responsiveness. Additionally, misalignment between the scale of good management measures and distribution of the stock (i.e., the lack of good fishery governance throughout the stock’s range) can result in overfishing within the fishery.
Although the trajectory of this fishery remains uncertain, it is clear that climate change promises to create future conditions that differ from past oceanographic conditions. Whether the inherent resilience of the Pacific sardine fishery will enable it to survive and thrive enough to allow for the sizable commercial harvests that periodically occur in the face of this change remains unknown. Similarly, whether the existing harvest control rule will provide a sufficient level of protection and harvest opportunity in the face of climate change also remains unknown. A management strategy evaluation, or similar exercise, would help shed light on these questions. However, evidence suggests that if fisheries respect and accept the importance of HCRs in enhancing future fishing opportunities within their systems, then they may be more willing to abide by formalized regulations and provide critical information to management to develop the health and success of the fishery. In order for this type of compliance and trust between fishers and management to prove successful, increasing the inclusion of fishers in these critical conversations and making sure they have a seat at the governance table will likely be critical (Kvasdal et al. 2016).
Kvamsdal, S. F., Eide, A., Ekerhovd, N., Enberg, K., Gudmundsdottir, A., Hoel, A., Mills, K. E., Mueter, F. J., Ravn-Jonsen, L., Sandal, L. K., Stiansen, J. E., Vestergaard, N. (2016). Harvest control rules in modern fisheries management. Elements: Science of the Anthropocene. 114(4), 1-22. doi:10.12952/journal.elementa.000114
McClatchie, S., Hendy, I. L., Thompson, A. R., & Watson, W. (2017). Collapse and recovery of forage fish populations prior to commercial exploitation. Geophysical Research Letters, 44(4), 1877-1885. doi:10.1002/2016GL071751.
NOAA Fisheries (2020). Species directory: Pacific Sardine. Retrieved from https://www.fisheries.noaa.gov/species/pacific-sardine
Pacific Fishery Management Council (2021). Coastal Pelagic Species Fishery Management Plan. National Oceanic and Atmospheric Administration. 1-50.
Smith, J. A., Muhling, B., Sweeney, J., Tommasi, D., Pozo Buil, M., Fiechter, J., & Jacox, M. G. (2021). The potential impact of a shifting Pacific sardine distribution on U.S. West Coast landings. Fisheries Oceanography 30(4), 437-454. doi:10.1111/fog.12529.
Sustainable Fisheries (2016). The Pacific Sardine. University of Washington. Retrieved from https://sustainablefisheries-uw.org/fishery-feature/the-pacific-sardine-sardinops-sagax/
Photo: Fishing vessels in Monterey Bay, California. Credit: Kip Evans/Alamy