How to Not Close Salmon Fisheries

California salmon fisheries do not have to close. Hatcheries in California are still releasing thirty million hatchery smolts each year. This means that three to five hundred thousand adult hatchery salmon are still out there for potential harvest. About a quarter of the fish released from hatcheries are marked. Selectively harvesting the marked hatchery fish, while returning to the water all unmarked fish that are caught, is reasonable.

Marking all the hatchery smolts would quadruple the number of harvestable fish.

Do not let anyone tell you this is not reasonable. The state and federal governments have mismanaged California’s natural salmon production nearly into oblivion. They can spend the money to partially mitigate the consequences by marking all hatchery fish.

two fish photo, showing fin removal

Photo of marked and unmarked hatchery fish. Photo credit: Idaho Dept. of Fish and Wildlife. In the Columbia basin, all hatchery salmon are marked, and thus hatchery fish and wild fish are immediately distinguishable.

For more information on mark selective fisheries see:


Guest Blog: Salmon Declines and Hatchery Options

(Editor’s Note: From time to time, the California Fisheries Blog gets requests for guest posts. We like to accommodate requests for posts that we feel, at our sole discretion, are substantive and thought-provoking. Though we discourage pseudonyms, we may, as here, allow posts without attribution when such posts allow a platform to speak out for persons who are professionally constrained. We reserve the right to edit guest posts for clarity. As with all posts on the California Fisheries Blog, guest posts do not represent the policy or opinions of CSPA.)

By “Kilgore Trout”

On Saturday (March 18, 2023), Sep Hendrickson’s “California Sportsmen” radio show hosted James Stone, current president of the Nor-Cal Guides and Sportsmen’s Association. The Association recently lobbied to close the California salmon fishing season for 2023. The discussion raised several interesting issues about the status and management of salmon.

Mr. Stone questioned why regulators did not close the salmon fishery earlier than this year. He noted that in 6 of the last 8 years, the annual escapement of Sacramento fall-run Chinook salmon was below the minimum conservation objective of 122,000 adults, a dismal 75% failure rate for forecasters.

As background, the Sacramento fall-run Chinook is the dominant salmon population commercially fished offshore of California. The population is an aggregate of hatchery and natural production, dominated by hatchery production. A year’s escapement is the abundance of adults that return (in the fall) to spawn in the Sacramento River, its tributaries, and hatcheries. The following spring, the fall-run Chinook offspring of natural-origin emerge from the gravel, smolt, and migrate seaward; the hatchery-origin fish artificially produced by broodstock matings are fed and reared as fry and smolts (in raceways or ponds), then released near the hatchery, or trucked to the estuary or Bay for release.

Sep and James agreed that all too often, 100% of California’s recent salmon declines are blamed on climate change and droughts, not factors like overfishing after years of low escapement. Indeed, a NOAA study conducted after the 2008 closure of the California salmon fishery attributed the collapse primarily to poor ocean conditions, but also noted contributing factors like dry inland conditions and fishing.

Sep and James continued to discuss water management in California’s Central Valley. James reminded listeners that California’s Fish and Game Code 5937 requires dam operators to release water to protect fish. This is correct, and it seems that conservation objectives for salmon (like suitable river temperatures and minimum escapement numbers) should be established to account for environmental variations like hot summers and dry winters that contribute to poor brood years. What’s the point of establishing salmon protections if we scream “Emergency!” and toss protections aside whenever consecutive dry years put agricultural or municipal water users in a short-term bind?

But water management to conserve salmon is not as simple as host Sep Hendrickson framed it when he contended, “There is water behind dams that is oxygenated that can be added and cool at any time they want to; they choose not to.” There isn’t always enough water, and it’s not as simple as saying that politicians simply choose not to release it from dams.

Salmon juveniles emerging from the gravel near Redding must travel hundreds of river miles downstream, where they enter and transit the Delta and Bay to reach the Pacific. That means the Sacramento River must be cold enough for salmon from Redding to the Bay. At the same time, water is released from reservoir storage for agricultural and municipal uses. For there to be enough cold water in the bottom strata of Shasta Reservoir to cool the Sacramento River for salmon, water released from the reservoir in any year must both keep the river cold and retain enough water in storage so that it stays cold later in the year. Shasta’s operators must also retain enough water in storage to allow cold water management in the following year if the following year is dry.

There isn’t space here for a full discussion of Sacramento River water supply and use, or the constraints on achieving temperature (and other) requirements for salmon. This would involve considering complex topics like salmon biology, climate, flood control, drought management, federal water contracts, State water rights, Delta salinity, ocean conditions, and others. But the issues are more complex than politicians (like our Governor) simply choosing not to release water for salmon.

Recognizing the gravity of the Sacramento fall-run Chinook collapse, James Stone warned, “If we don’t raise more hatchery fish, we could possibly lose the fall run forever.” Sep Hendrickson responded, “We need a state-of-the-art hatchery. We can do this state with one hatchery, centrally located that handles everything…” James Stone told listeners they could join the Nor-Cal Guides and Sportsmen’s Association, which has lobbied since 2019 for funds (up to $100 million) for a new hatchery on the mainstem Sacramento River. Stone described it as a modern facility that would allow the trucking of fish and the return of fish, and help protect our stocks for many years. The hatchery’s objective would be to “re-colonize and re-populate the Sacramento River with hatchery fish” and “get them to spawn in the rivers and start reproducing the natural spawn.” Stone added that a healthy river is the best hatchery because it could produce millions more salmon eggs than a hatchery.

Getting funds could help if the objective of “…reproducing the natural spawn” could be achieved by supplementing the production of natural-origin salmon in the Sacramento River watershed.  But would another large, production hatchery “reproduce” the natural spawn, or hasten its replacement?

After all, hatcheries in the Sacramento River watershed already produce and release millions of Sacramento fall-run Chinook. The Coleman National Fish Hatchery (Battle Creek) releases 12 million fall-run Chinook smolts annually. The Feather River Hatchery has an annual goal to release 6 million smolts, and the Nimbus Fish Hatchery (American River) another 4 million. Other Central Valley hatcheries not in the Sacramento River watershed also release fall-run Chinook. The goal of the Mokelumne River Fish Hatchery is to release 5 million smolts, with an additional 2 million released into San Pablo Bay or into acclimation pens in the ocean. The Feather River Hatchery also produces an additional 2 million fall-run Chinook to truck downstream for an ocean enhancement program. Before building another large hatchery, it seems fair to ask why releasing millions of hatchery fall-run Chinook – year after year – hasn’t already reproduced the natural spawn.

What if current hatchery practices are also exerting negative effects on Sacramento fall-run Chinook, like overfishing and unbalanced water management do? Yes, some California hatchery facilities are very old, but what if investing $100 million to bring them to state-of-the-art production levels makes at least some things worse?

Ditto for building “one hatchery, centrally located that handles everything…” We already know that very little population structure remains in the Sacramento fall-run Chinook; the variation or diversity that once existed has been greatly diminished from the time when they thrived not only in the Sacramento River, but also in large tributaries like the Feather, Yuba, and American rivers, and in numerous other smaller rivers and streams in the watershed. Large dams that eliminated nearly all the upstream natal habitat of the winter-run and spring-run Chinook are generally regarded as the primary cause of the demise of these stocks. But the dams did not eliminate nearly as much fall-run Chinook habitat because the fall-run do not migrate as far upstream to spawn. So, relative to habitat loss due to dams, did hatcheries play a larger role in the “homogenization” observed in the fall-run Chinook stock?

We know that salmon in streams do not select mates randomly, so the random mate selection in hatcheries effectively eliminates adult competition. We also know that captive rearing and feeding of juvenile salmon minimizes the mortality that would naturally occur in a river. Do juvenile salmon in hatchery ponds acquire food or avoid predators the same as fish in the wild? It also makes sense that wild juveniles migrating hundreds of miles in a river must adapt to more perilous environments than do hatchery fish transported in trucks. Are the consequences of these hatchery effects the losses of vigor, the ability to adapt to local environments and variation, and evolutionary fitness?

It seems we could better understand hatchery effects by spending some of the $100 million on modern salmon monitoring. Genetics-based tools already exist, so that all hatchery broodstock can be tissue-sampled and genotyped, with the information stored in a computer database. All hatchery offspring (millions of fish) would be effectively “tagged” and their hatchery of origin could be identified later, if they are genotyped when captured — in the fishery, after straying to the natural spawning grounds, when interbreeding with wild fish, etc. Similarly, tissues from salmon carcasses on the natural spawning grounds could be collected and genotyped (they are already surveyed every year by the California Department of Fish and Wildlife). This process would genetically “tag” the natural-born offspring in the Sacramento River and its tributaries.

These tools would allow biologists and managers to know the origin of a salmon. They could also better understand the effects of artificial propagation, such as interbreeding, on natural-origin fish. We could begin to understand if hatcheries could “re-colonize and re-populate the Sacramento River with hatchery fish” and “get them to spawn in the rivers and start reproducing the natural spawn.”

An alternative to building and ramping up another large production hatchery might be  to try (mobile) conservation hatchery set-ups, to temporarily supplement wild stocks in the Sacramento River and tributaries. With genetic tagging, we could know how well the offspring survive to return and spawn, and how successful their offspring are at surviving and reproducing. We could detect if and when the rivers get healthier, and begin producing more eggs and adult salmon than the hatcheries do. We might get to a place where there is no need to clip adipose fins.

Let’s start working together to recover salmon!

With Salmon Season Closed for 2023, the Work is Just Beginning

The final rules adopted by NOAA Fisheries and California Department of Fish and Wildlife this spring will be much different than last year’s rules.  The 2023 commercial and sport fishing closure is designed to ensure that adequate numbers of fall run salmon, the primary stock of the fishery, return to spawn this year and  begin the recovery of the population to allow future fisheries.  The Pacific Fisheries Management Council (PFMC) and the California Fish and Game Commission are taking this extreme action as their authorized contribution to the recovery of collapsed California’s salmon populations.  This year’s salmon closure follows yet another three-year drought (2020-2022) and associated water mismanagement.

But the work does not stop at closing the season.  The legal authorities of other state and federal agencies must now kick in and do their part.  With the salmon out in the ocean now protected, the next steps are to protect broodyear 2022 that is now in the rivers and the Bay-Delta estuary, and to be ready for the return of remaining broodyear 2019 and broodyear 2020 and 2021 adult salmon that will re-enter fresh water to spawn this fall and next year.

Hatchery Production

There are 20 million or so fall-run salmon pre-smolts soon to be released this spring from the seven Central Valley salmon hatcheries.  Hatchery personnel will release these salmon to the rivers, Delta, Bay, and coast.  Where and when they do so will greatly affect how many salmon reach the ocean and return to the rivers to spawn (escapement).

The following measures if adopted will increase success:

  • Truck as many smolts as possible to the coast and Golden Gate. Hold as many as these as possible for late spring, summer, and late fall (yearling) release.
  • Limit in-Delta and East Bay releases, because to succeed they must occur in early spring when receiving waters are cool. Early spring releases are smaller fish that do not survive as well, especially if they are released near the hatcheries.
  • Coordinate river (near-hatchery) releases in spring with river and Delta inflow/outflow flow pulses and with optimal water temperature and turbidity conditions.
  • Appropriately clip all adipose fins, and coded-wire tag all smolts.
  • Track and analyze survival under varying release strategies.
  • Adopt a Parental-Based-Tagging (PBT) program to support the overall recovery program.
  • Fund and implement hatchery program facilities and operational improvements, as recommended and planned by agencies.

Natural Production

Millions of eggs will be spawned in rivers this fall, despite what may be a near-record-low number of returning adults (escapement) in 2023.  It is imperative that the young salmon hatched from these eggs survive and contribute a maximum of natural-born smolts to the ocean.  We are so lucky that Mother Nature has provided the necessary water resources this year to allow that to happen.

As it is, only 32,000 adult salmon spawned naturally in rivers last fall, compared to 300,000 just a decade ago.  The earlier 2010-2016 recovery was a great accomplishment soon after the 2007-2009 population crash, when natural born escapement was only 25,000-70,000 (see Table 1).  That recovery was brought about after two years of fisheries closures (2008-2009) and three relatively abundant water years (2010-2012).

The following measures if adopted will increase success:

  • Provide coordinated spring river flow pulses with storage reservoir releases and/or foregone water diversions (if necessary).
  • Maintain minimum flows in rivers to meet or exceed year-round water temperature standards.
  • Limit south Delta exports during natural or induced flow pulses, and otherwise follow the export restrictions required in the 2008-2009 Biological Opinion.
  • Minimize salmon egg, embryo, and fry stranding in spawning gravel beds (redds) that occur when reservoir releases are reduced after spawning has occurred.
  • Minimize stranding, entrainment, or adverse water temperature changes caused by otherwise legal water diversions.
  • Limit agricultural or municipal waste water discharges that may increase water temperature in key salmon habitats.
  • Upgrade gravel supplies in prime spawning habitats before next fall’s spawning season.

Future Fisheries

In addition to closing fisheries and limiting harvest this year, it will likely be necessary to limit harvest in 2024 and 2025.  This is because of the over-harvest in 2021 and 2022 of broodyears 2018 and 2019 (Figure 1), which will likely lead to poor returns from broodyears 2021 and 2022 (Figure 2).  Broodyear 2021 is of special concern, because, like broodyear 2020 (whose poor prognosis for 2023 escapement led to the fishery closure), broodyear 2021 reared and out-migrated in a critical drought year (2022).

The following measures if adopted will increase success:

  • Plan for a closure in 2024 to protect an expected poor return from broodyear 2021.
  • Consider as an option for the 2024 and 2025 seasons a mark-selective fishery if the measures under Hatchery Production outlined above are accomplished and show signs of being effective.

Other recommended actions

Chinook escapement in Sacramento River

Table 1. Source: PFMC.

Graph of Sacramento Index from 1983 through 2022

Figure 1. Sacramento River fall-run Chinook salmon population index comprised of escapement (natural areas and hatchery counts) and river and ocean harvests. (Source: PFMC)

Graph recruits versus spawners

Figure 2. Author-developed spawner-recruit relationship using total escapements in Table 1. Number shown is recruit year escapement (left y-axis is log(x) minus 4 of recruits) plotted against spawner escapement (x-axis, recruitment three years prior). Actual number is shown in log scale on right y-axis. Red lines are target PFMC escapement range for fishery. Red and blue circles show recruitment difference between wet and dry years at maximum sustained yield spawner levels. (Spawner levels of 300-500 thousand levels can yield 500,000 recruits from wet years or as few as 100,000 recruits from dry years). Note poor recruitment in 2021 and even less in dry year 2022 due to over-harvest.



Central Valley Hatchery Salmon Production Is Being Wasted A Tale of Two Hatchery Salmon Smolt Release Groups

There are two common strategies for releasing juvenile salmon from  state and federal salmon hatcheries in the Central Valley.  One strategy is the release of hatchery salmon smolts at or near the hatchery where they are produced.  The other strategy is trucking the smolts from the hatchery and releasing them into the Bay.  There is much controversy and argument over the relative merits of the strategies.  There can be little argument that release into the Bay generates far more adult salmon than release near the hatcheries.

Consider what occurred with two American River release groups after their release in May 2018 and return as adults in 2020.  Release group #061465 was 669,000 fall-run smolts (3-4 inches long) that were transported 20 miles downstream from the American River (Nimbus) Hatchery and released into the mouth of the American River under the Jibboom Street Bridge.  Release group #061467 was 650,000 fall-run smolts transported approximately 100 miles downstream to net pens at the Wickland Oil Terminal for release into eastern San Pablo Bay, about 20 miles from the Golden Gate Bridge and the Pacific Ocean.

The estimated percent survival based on tag recoveries was 0.04% for group #061465 (released near the hatchery).  The estimated percent survival was 2.20% for group #061467 (released in San Pablo Bay).  The returns by locations are shown in Figures 1 and 2.  These relative results are common.

Figure 1. Returns for tag group #061465.

Figure 2. Returns from tag group #061467.


State and Federal Hatcheries Release Salmon Smolts to Rivers, Delta, Bay, and Coast

Hatcheries in California are releasing tens of millions of salmon smolts in 2022, per normal operations.  State hatcheries are trucking over ten million fall-run salmon to the Bay again this spring because of the drought.  State and federal hatcheries are releasing another ten million-plus fall-run smolts to the rivers near the hatcheries.

Future salmon fisheries will depend mostly on the Bay releases, because few of the hatchery smolts released to the river or wild salmon smolts will survive the journey to the ocean this drought year.  Yet even the prognosis for smolts released to the Bay is poor.  Delta outflows near 4000 cfs under the State’s TUCP will keep survival below one percent (Figure 1).

Meanwhile, the prognosis for wild fall-run smolts under the TUCP is grim as they began moving through the Delta in late April and early May (Figures 2 and 3).  The extra month of normal outflow needed to help the salmon get to the ocean would amount to about 100-150 TAF, less than 10% of what is being supplied to water users from reservoirs in spring 2022.  Is the TUCP allocation to outflow and fish reasonable?

Figure 1. Fall-run salmon adult returns to the American River hatchery from Bay releases vs Delta outflow to Bay at time of release. Years noted are percent returns for below normal years 2016 and 2018, and wet year 2017 under normal rules. Blue dots with outflow below 5000 cfs are from 2014 and 2015, TUCP years. Red line is hypothesized relationship. Returns under normal rules are approximately triple the returns under TUCP rules.

Figure 2. Red circle denotes wild fall-run and spring-run smolts passing through the Delta in late April and early May 2022.

Figure 3. Peak migration of fall-run and spring-run smolts into Bay from Delta in late April and early May 2022.