Monday May 13, 2024
For the past several weeks, news of the salmon fishery closure for the second straight year has been circulating broadly. To understand more about the population and the impacts of the closure, we like to take the opportunity to look back at key findings from the previous years salmon fishery. The 2023 salmon population continued the downward trend exhibited in previous years, and although the fishery was closed last year, the overall spawning population was just barely above statewide management goals. Poor predicted abundance again this year led harvest managers to make the tough call to close the fishery, which will undoubtedly cause hardships for anglers and industries statewide. Nevertheless, these restrictions have ultimately proved effective at ensuring successful spawning after several years of drought and diminishing returns.
Each year, the Pacific Fishery Management Council (PFMC) publishes a report on the previous year’s salmon fisheries along the West Coast, which details harvest totals and socioeconomic benefits from the California ocean fishery. It also includes escapement totals – or the number of salmon that “escaped” the fishery and returned to the Central Valley to spawn – and provides an opportunity to compare these numbers with the preseason predictions that are used to set harvest regulations for that year. Inaccurate preseason predictions can have severe consequences, an underestimation can impose unnecessary restrictions on the commercial fishery, and an overestimation can lead to reduced escapement and low numbers of fish available for in-river recreational fishing. Since 2005, Central Valley salmon abundance has been overestimated in over 75% of years (Figure 1), which continues to hamper effective management of the fishery. In 2023, the population was overestimated once again with an actual population 18% smaller than that forecasted.
Figure 1. Percent difference from PFMC average annual preseason forecast relative to the actual SI observed, 1985-2023. Vertical red line indicates an apparent trend shift to overestimation from 2005 onwards. Source: PFMC Preseason Report I: Stock Abundance Analysis and Environmental Assessment Part 1 for 2024 Ocean Salmon Fishery Regulations.
In California, the PFMC report highlights fall-run Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento River Basin, as this population contributes the majority of fish caught in the ocean fishery. The metric used to represent the abundance of this population is the Sacramento Index (SI), which is the total number of adult fish (ages 3-5) projected to be available in the ocean – either to be harvested or to escape to spawn in natural areas or hatcheries in the Central Valley. The preseason forecast for 2023 predicted an SI of 169,767 fish, with a total projected spawning escapement of 164,964 hatchery and natural area spawners, based on fishing regulations and quotas. This predicted SI was the lowest forecasted abundance since 2009, which was also the last time that the fishery was closed in California. PFMC reported that the 2023 salmon season resulted in an actual SI of 139,487 fish, which was a 45% decline from the preceding year and 58% lower than the previous five-year average of 331,100 fish. Given the shutdown of the fishery in California, the exploitation rate, or the percentage of fish that were commercially harvested, was only 4% – the lowest rate since 2009. As a result, the majority of the salmon population returned to Central Valley rivers and hatcheries to spawn.
An estimated 133,638 fall-run Chinook salmon “escaped” the harvest and spawned in hatcheries and natural areas of the Sacramento Basin in 2023, which is above the long-term management goal of 122,000 hatchery and natural area spawners. Escapement in 2023 was 116% higher than the previous year’s total of 61,850, and 16% higher than the previous five-year average of 114,722 (Figure 2). Based on the mean spawning escapement from the prior three years, the Sacramento Basin population met the criteria for “overfished” status every year from 2018 to 2021. Interestingly, when compared against the current three-year mean spawning escapement (95,569), the stock is not considered overfished at this time, and actually remains slightly higher than the minimum stock size threshold (91,500). This year’s number of natural-area spawners (105,612) exceeded the number of hatchery returns (28,026), which is common in most years, but is sometimes reversed in low-escapement years such as 2017 (Figure 3). Notably, hatchery-origin fish likely comprise a large percentage of the natural area spawners.
Figure 2. Sacramento River fall-run Chinook salmon ocean harvest, river harvest, and escapement, 1985-2023. Source: PFMC Preseason Report I: Stock Abundance Analysis and Environmental Assessment Part 1 for 2024 Ocean Salmon Fishery Regulations.
The salmon returning in 2023 to the Sacramento River Basin were likely influenced by relatively poor outmigration conditions in 2021, when the majority of the returning fish originally outmigrated to the ocean. Outmigration occurred during a second consecutive year of extreme drought in California, which is known to cause poor survival due to the impacts of low flows and high temperatures. Even so, while survival in the San Joaquin River (SJR) Basin is generally much lower than in the Sacramento River Basin, returns to the SJR Basin increased by 262% over the prior year, with a total estimated escapement of 29,425 salmon or 19% of the Central Valley total. The majority of these fish returned to the Mokelumne River, which received roughly 73% of all natural area spawners, followed by the Merced (10%), Stanislaus (6%), Tuolumne (6%), and Calaveras and Cosumnes rivers (combined total of 5%). The SJR Basin has historically constituted less than 10% of the total Central Valley escapement, but since 2015, its contribution has exceeded 10% every year, with an average contribution of 14%.
Fishing poles on a pier.
A total of 21,572 fall-run Chinook salmon returned to natural areas of the SJR basin, with the majority of those salmon returning to the Mokelumne and Merced river hatcheries (7,853 salmon combined). Similar to the Sacramento Basin, it is likely that hatchery-origin fish also comprise a large percentage of the natural area spawners in this system. It is not clear why the proportion of escapement has been relatively high in the SJR Basin over the past few years, but may be partially attributed to increased trucking and release of hatchery smolts at off-site locations during the drought leading to increased straying of returning adults from other basins. For example, the Mokelumne River made headlines in 2023 for high numbers of returning salmon, but this basin is home to one of the few hatcheries that has consistently trucked the majority of their fish production directly to the San Francisco Bay, thereby improving juvenile survival and boosting the number of returning adults to the Mokelumne River and other nearby basins.
In 2023, no salmon were landed in California for the first time since 2009 due to a closure of the commercial and recreational fisheries. As a result of the closure, the highest landings by weight were recorded at ports in Washington. Over the previous four years (2019-2022), between 79-85% of the Pacific Coast commercial Chinook landings by weight were landed in the three southernmost California port areas – Fort Bragg, San Francisco, and Monterey (Figure 4). Prior to 2019, the average annual share landed in these three ports was approximately 40%, with San Francisco producing approximately 25% of the total coastwide landings. Data from the prior year suggests the fishery closure resulted in a loss of over $17 million in revenue for the California commercial fishery. In comparison, the 1979-1990 inflation-adjusted average of landings revenue from the commercial fishery – which at the time included coho salmon (O. kisutch) landings – was $40.5 million.
Figure 3. Pounds of salmon landed by the commercial troll ocean fishery by state 2006-2023. Source: PFMC Preseason Report I: Stock Abundance Analysis and Environmental Assessment Part 1 for 2024 Ocean Salmon Fishery Regulations.
Unfortunately, anglers and commercial fishers received unwelcome news from PFMC this year, with reduced forecasts leading to the second multi-year fishery closure in California’s history, with the previous closure occurring in 2008-2009. If preseason forecasts are correct, there will be an estimated 213,622 Sacramento River fall-run Chinook salmon in the ocean this year. This forecast is a 26% increase from last year’s projection, but still 37% lower than the previous five-year average of 338,000. In what has become an all too familiar refrain in recent years, California will be facing dire economic and ecological impacts from a closed fishery and reduced returns to Central Valley rivers. Fortunately, it is expected that recreational and commercial fisheries closures will have a positive effect on stock numbers by preventing overexploitation of vulnerable stocks and fish returning in 2025 should benefit from better conditions experienced during their outmigration. With two years of high flows and closed fisheries allowing salmon a chance to recover, there’s reason to be optimistic about the fishery in the years to come.
Header Image: A Chinook salmon.
This post was featured in our weekly e-newsletter, the Fish Report. You can subscribe to the Fish Report here.