In March, the state’s Department of Fish and Wildlife delivered grim news to Californians: only 62,000 adult Chinook salmon had returned from the Pacific Ocean to Sacramento River basin tributaries in 2022. The number is substantially fewer than the targeted minimum of 125,000 fish set by the Pacific Fishery Management Council (PFMC), the entity that manages groundfish, coastal pelagic species, highly migratory species, and salmon fisheries on the West Coast of the United States. In response to the discouraging numbers, the salmon fishing season for 2023 was closed, putting hundreds of commercial fishers out of work and disappointing thousands of recreational fishers. As might be expected, finger-pointing ensued. Ocean commercial fishing interests and allies among some environmental organizations have been the loudest critics, directing blame on the management of California’s river waters, particularly water allocations to farmers and urban water users. Reports and posts accompanying the salmon season closure have been rife with misinformation, repeating three persistent and self-serving myths regarding the factors that have contributed to the imperiled state of Central Valley salmon runs. What are those myths?

Myth number one — Ocean harvest of Chinook salmon is not contributing to the continuing decline of central California’s salmon runs

Conservation planning for California salmon focuses on their freshwater habitats, with attention to spawning and rearing habitats, predation on young salmon, freshwater flows, and entrainment at water export pumps in the south Sacramento-San Joaquin Delta — worthy concerns for sure. But policymakers, resource managers, and many biologists give scant consideration to the effect ocean salmon fishery limits have on the abundance and recovery potential of California Chinook salmon. Ocean commercial fishing interests, again with backing from some prominent environmental organizations, and even regulatory agencies, have for decades effectively executed this “look over there, not at us” strategy.

There is a general assumption that harvest off the coast of California is being managed with great attention and care, such that wild and endangered salmon are well-protected from ocean harvest impacts. But that’s not the case. In fact, California is the wild west of ocean salmon fisheries. The intensity of California’s ocean Chinook salmon harvest is rivaled only by the fisheries of southwest Alaska. 

South of the Klamath Management Zone in coastal California, it is estimated that nearly 2.3 million pounds of Chinook salmon were harvested by commercial fishermen in 2022. In contrast, just 357 thousand pounds and 224 thousand pounds were commercially harvested off the coasts of Oregon and Washington, respectively. Commercial harvest for the San Francisco and Monterey regions was projected at 62,000 salmon in 2022, but instead, nearly 190,000 fish were harvested. Commercial harvest exceeding the level projected by fishery regulators in 2022 was the single largest contributor to the subsequent low abundance of Sacramento River fall-run spawners. 

In the Pacific Northwest, where Native American tribes and environmental organizations actively scrutinize ocean-harvest salmon management, litigation challenging fishery management decisions is commonplace. Quotas, mass marking of hatchery-produced fish, and other management strategies are applied to prevent over-harvest of sensitive stocks. In the Klamath basin, and further north in the Pacific Northwest, Native American tribes are guaranteed a substantial allocation of adult salmon returns. Their tribal claims, protections for stocks listed under the federal Endangered Species Act (ESA), and other spawning escapement minimums greatly constrain take from ocean fisheries along the northern West Coast. But not so for California fisheries south of Cape Mendocino.  

The PFMC manages ocean salmon fisheries off Washington, Oregon, and California coasts. The PFMC imposes ocean fishing regulations based on an assortment of control rules. Take limits for ESA-listed stocks are specified by the National Marine Fisheries Service. Efforts to reduce impacts on ESA-listed stocks have been addressed by management guidelines, including shifting fishing seasons and size limits. 

Despite repeated incidents of too many salmon being harvested and poorly monitored impacts to wild and ESA-listed stocks, California’s ocean fishery remains uniquely aggressive in the number of salmon taken annually. The ocean harvest exploitation rate — the proportion of fall-run Chinook salmon that would have returned to spawn but were instead lost to ocean fishing mortality — has averaged 56% since 2014.  This relentless ocean-harvest pressure on California salmon dwarfs many of the freshwater factors which have been the focus of regulators and of litigation. Ocean exploitation was estimated at 73% in 2022 and again was the major contributing factor forcing the closure of the 2023 salmon season. 

Weak stocks like the Sacramento winter-run Chinook, Central Valley spring-run Chinook, California Coastal Chinook (CCC), and wild Central Valley fall-run Chinook co-occur in a mixed-stock fishery with the abundant, hatchery-supported fall-run Chinook. In those circumstances, where weak stocks are intermingled with an abundant hatchery stock, a high exploitation rate on the abundant hatchery stock puts the weak stocks at extraordinary risk of unsustainable harvest impacts.  

It should be understood that ocean harvest impacts on weak California salmon stocks are recognized as a serious concern, but they are simply not monitored or managed accordingly.  

Ocean harvest impacts on Central Valley spring-run Chinook salmon are not estimated and do not directly influence ocean harvest management decisions. 

Ocean harvest impacts on California Coastal Chinook are not estimated. Instead, coded wire-tagged Klamath hatchery Chinook salmon are used as a surrogate or indicator stock for CCC. However, the surrogate’s effectiveness in protecting CCC from ocean harvest is unknown. In fact, the CCC surrogate was chosen based on its availability, not on its demonstrated effectiveness in guiding CCC harvest protections. 

Ocean harvest impacts on natural-origin (wild) Central Valley fall-run Chinook are not estimated or considered in harvest management. Although Central Valley fall-run are not listed under the ESA, increasing their abundance is a primary goal of the Voluntary Agreement framework under development and numerous other freshwater management actions. If ocean harvest of wild fall-run Chinook continues to be neither monitored nor managed, it will severely hinder benefits that might be realized from Voluntary Agreement efforts and other resource- and dollar-expensive freshwater management actions. 

The Sacramento winter-run Chinook salmon is the only weak stock directly monitored and managed for ocean-harvest impacts. But even for winter-run salmon, the monitoring and management agenda is incomplete. Only the harvest of hatchery produced winter-run Chinook maturing at age-3 is considered, despite the fact that at least 8% of the population is known to mature at age-4 (RJ Hallock and FW Fisher. Status of winter-run Chinook salmon, Oncorhynchus tshawytscha, in the Sacramento River. Anadromous Fisheries Branch, California Department of Fish and Game. Office Report, 25 January 1985). Managing to conserve and expand this kind of life history diversity has been a major priority for regulators concerned with freshwater flows and habitats, but it has been ignored by regulators with respect to ocean harvest and hatchery impacts.   

Myth number two — Hatchery salmon are the same as wild salmon

Those big numbers of salmon harvested off the central California coast are made possible by hatchery production. Hatchery salmon and their wild kin are indistinguishable to commercial and recreational fishers. However, biologists know that hatchery salmon can be expected to differ from wild salmon in their ability to spawn successfully and to produce offspring that can grow and survive the first few months after they emerge from spawning gravels. 

Generations of salmon spawned and reared in hatcheries have adapted to thrive in an artificial environment. They are bred for a purpose, namely, to be successful in the hatchery environment and to survive after release as smolts until harvest. An analogy may help to explain the point. A Labrador retriever bred and trained for success at the Westminster Dog Show might look like the pinnacle of its breed, but a duck hunter would never expect such a dog to perform in the field. Salmon fishing interests often do not acknowledge that the same basic principles of natural selection apply to salmon. 

Hatchery Scientific Review Groups (HSRGs) in the Pacific Northwest, and in California in 2012, recommend practices that can help to minimize adverse effects on wild stocks while still allowing hatcheries to function. The California HSRG, for example, recommended substantive and scientifically well-supported changes to managing hatchery salmon, including mass marking/tagging, expanded use of wild fish in hatchery brood-stock, on-site smolt releases, and improved ocean harvest management. However, none of those recommendations have been implemented — many hatchery salmon are still being trucked downstream before release, only 25% of fall-run Chinook are regularly marked, and wild fish continue to be nearly absent from hatchery brood-stock. HSRG recommendations could be formalized as regulatory requirements through Hatchery Genetics and Management Plans (HGMPs), a legal requirement for compliance with the ESA. But none of the four State-operated Central Valley hatcheries propagating fall-run Chinook or steelhead have completed an HGMP. 

Though HSRG recommendations have not been followed and HGMPs have not been completed, fishing interests nonetheless blame those policies for declining numbers of harvestable California salmon. Agency scientists and regulators know better. They know that outdated hatchery management practices have contributed mightily to the decline of Central Valley salmon and steelhead. Forthright engagement with fishing interests could correct this confusion and facilitate advancement of appropriate hatchery-reform measures. Unfortunately, having such a conversation violates the “look over there, not at us” philosophy that seems to dictate the priorities of many salmon stakeholders, environmental organizations, and regulators. 

Myth number three — Water project operations are the primary cause of the decline in salmon numbers

There is no argument that the construction of dams, levees, and diversions on the tributary rivers feeding the Sacramento-San Joaquin Delta has been the dominant factor contributing to the decline of Central Valley salmon runs over the last century. But that reality has spawned the notion that ongoing operations of the existing dams and the water-export projects in the south Delta are the most significant contributors to current salmon mortality and recent declines in all the Central Valley runs. 

Proponents of that reasoning point to tagging studies showing improved survival of juvenile Chinook salmon during wet water years. That is, the more water in the Central Valley system of waterways, the more salmon survive. Wet water years, years with higher precipitation, generate elevated flows through the system, cooler water temperatures, increased turbidity, and habitat inundation. All of those factors contribute to salmon survival. The contention, then, is that water exports from the Delta reduce wet-year benefits, thereby contributing to reduced salmon survival. However, water exports from the Delta in wet years show no effect on salmon numbers; Central Valley salmon do better in wet years and poorer in dry years regardless of water-export volumes.

Ocean salmon fishing interests follow this faulty line of reasoning to explain declining salmon harvest opportunities. They point to the 1980s — when ocean harvest exceeded 1.2 million salmon — to illustrate “how good things were” before water-project operations ramped up.  While it is a popular story among ocean fishing interests, that explanation is directly contradicted by data. 

The best years for commercial salmon harvest occurred when water exports from the Delta in the springtime — when most juvenile salmon emigrate — were at their greatest (Figure 1). In fact, the decline in ocean salmon harvest is strongly correlated with recent decreases in spring season exports. Are declining spring exports the cause of the decline in salmon numbers? Surely not, but it is clear to anyone paying attention to the available scientific evidence that spring water-export restrictions are not helping salmon toward recovery.

Chart, line chart Description automatically generated

Figure 1 — Total discharge of the Sacramento River at Freeport, March-May (top panel), CVP/SWP combined exports, March-May (middle panel), and total Chinook salmon ocean harvest two years later (bottom panel). Ocean harvest data lagged by two years to align Sacramento River flows and exports with the freshwater conditions experienced by emigrating fall-run Chinook salmon maturing at age-3.  Highest levels of ocean harvest co-occurred with the highest levels of exports. Flow data from DWR’s Day Flow. Harvest data from the PFMC.   

While it would certainly be desirable if water-project operations could be managed to produce favorable conditions for salmon in drought years – that is, comparable to wet-year conditions – that probably isn’t possible. Managed flow pulses from upstream reservoir releases in drier years could be helpful in contributing to survival of out-migrating juvenile salmon; however, the benefits to salmon of such flow pulses have not been evaluated. And ironically, the greatest obstacle to such flow pulses are stringent spring water-export restrictions supported by salmon fishing interests and their allies in environmental organizations. 

Beyond the myths

There is no question that California salmon need help. Whether deliberate or accidental, myths about the causes of salmon decline are a significant impediment to making progress in reversing the declines in Central Valley salmon runs. Knowledgeable scientists, policymakers, and stakeholders need to openly acknowledge that helping California’s embattled Chinook salmon requires an “All H” approach. We need to address all four pernicious problems related to salmon — habitat, hydrology, hatcheries, and harvest. 

Stakeholders, policy advocates, and agency representatives asserting that dwindling salmon numbers are solely related to water management, while habitat, hatcheries, and harvest matter less or not at all in meeting the conservation challenge of saving California’s salmon, are either ignorant or deliberately undermining meaningful progress in conserving salmon.

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