Wishful Thinking on The Upcoming 2022 Salmon Season

We should be careful about wishful thinking in considering the forecasts for the 2022 California salmon season along the coast and in major rivers.1  The 2022 ocean abundance projection for Sacramento River fall Chinook, a main salmon stock harvested in California waters, is estimated at 396,500 adult salmon, a higher number than the 2021 forecasts. However, we should expect further drought-related fishery and escapement downturns in 2022 and 2023, as occurred after the 2007-2009 and 2013-2015 droughts (Figure 1). We can also expect low fishery catches, especially in rivers from low summer flows and associated high water temperatures that keep river spawners in the Bay until rivers cool in the fall.

The issues relate primarily to remaining stocks of Chinook salmon, not to the nearly extinct endangered Coho. The 2022 season also relates mostly to the availability of brood year 2019 salmon from Central Valley rivers, not coastal streams. Finally, it is important to remember that most of the adult salmon in 2022 will come from hatcheries on the Klamath, Trinity, Sacramento, Feather, American, Mokelumne, and Merced rivers, especially those hatcheries that truck and barge salmon to the Bay or coast.

Hatchery returns, the backbone of California salmon fisheries, are likely to be lower in 2022 than expected. Near 40 million Chinook salmon smolts from brood year 2019 were released from California federal and state hatcheries in 2020. Of the total, about 26 million were raised at Sacramento River watershed hatcheries, 9 million at San Joaquin River hatcheries, and 4 million at Klamath-Trinity hatcheries. Most of the releases were fall-run (34 million), with about 4 million spring-run, 1 million late-fall-run, and 0.4 million winter-run. Their returns of jacks and adults are likely to be lower in 2022 than expected because of low Delta inflows and outflows (Figure 2) and low Klamath-Trinity flows (Figures 3 and 4) in winter-spring 2020 and 2021, which are likely to result overall in relatively poor returns from river and Bay releases of hatchery smolts.2

Wild salmon stocks, already severely depressed, are going to further decline and contribute even less to fisheries. Natural production of brood years 2019 and 2020 was likely poor because wild smolts faced dry-year conditions in winter-spring 2020 and 2021, respectively.

Adult salmon that return to spawn in 2022 will face warm rivers, as they did in 2021 (Figures 5 and 6). They will be delayed, and many will die before spawning.

In summary, we must be careful about wishful thinking about the future based on the recently released ocean abundance estimate for 2022. Many other factors point in a downward direction. Perhaps the most immediate question is whethersalmon will simmer again in what looks to be a dry, hot summer.

Figure 1. Sacramento River Basin fall-run salmon escapement 1975-2020.

Figure 2. Sacramento-San Joaquin Delta outflow 2014-2022.

Figure 3. Klamath River flow at Orleans 2014-2022.

Figure 4. Trinity River flow at Hoopa 2014-2022.

Figure 5. Flow and water temperature in the lower Sacramento River at Wilkins Slough in 2021. Red line is 20ºC (68F) water quality standard and safe upper level for salmon.

Figure 6. Water temperature at Wilkins Slough in 2021 and recent historical average.

Salmon Released from Central Valley Hatcheries

Hundreds of thousands of smolts of endangered salmon are being released to the lower Sacramento River from federal and state hatcheries this winter, the San Francisco Chronicle reported on March 2.1 It is a drought year, and most of the young salmon will likely perish in the jaws of predators on their 300-mile journey to the ocean through the river, Delta, and Bay. Without the protection of adequate river flow, cold water, and turbidity for the journey, there is little hope. Reservoir storage is depleted from the past two years of overzealous water deliveries. What little rain and snowmelt there has been in the Valley is being stored in reservoirs. Warm weather has come early. The 400 thousand smolts released on March 2 could use some help, but they have not received it and are not likely to get it.

River Flow

Flow from Shasta Reservoir to the upper river via Keswick Dam has been minimal (Figure 1, KWK). 40 miles downstream at the Bend (BND) gage near Red Bluff, the river received some snowmelt from tributaries in January, but even that tapered off by the end of January. Flow into the Delta from the Sacramento Valley at Freeport (FPT) reached minimal levels by the end of January. Delta outflow (Figure 2) settled at its minimal prescribed level near 12,000 cfs after some January export taking.

Water Temperature

Warm weather and low flows have allowed water temperatures in the lower Sacramento River and north Delta migration corridor to reach the mid-fifties (Figure 3), temperatures that activate lower river predators like striped bass, resident trout, and pikeminnow.

Turbidity

Turbidities (Figure 4) are now at seasonal lows from the upper river near Red Bluff (RDB) to the Delta near the Rio Vista Bridge (RVB), reflecting clear waters needed by sight-feeding predators like striped bass.

Delta Salmon Salvage

Hatchery salmon smolts released in December at least reached the Delta during the December storms (Figure 5). It remains to be seen if the February and March smolt releases even reach the Delta.

What’s Needed

The article in the Chronicle mentioned that only one of the 140 radio-tagged hatchery smolts released in February has reached the Delta. The March 2 release of 400,000 smolts could use a pulse of cold turbid water from Shasta, Oroville and Folsom reservoirs to help them reach the Bay. So far, only Oroville releases have increased, from 3500 to 5500 cfs in recent days, with the added 2000 cfs showing at Freeport (Figure 1). While this helps near the Delta, it does little for the upper 200 miles of river the smolts have yet to transit.

Figure 1. River flows near Keswick (River Mile-RM 300), Bend (RM 250), and Freeport (RM 50) in winter 2022.

Figure 2. Delta outflow in tidally averaged daily cfs in winter 2022.

Figure 3. Water temperature in Sacramento River near Bend (RM 250), Wilkins Slough (RM 140) and Freeport (RM 50) in winter 2022.

Figure 4. Water turbidity in Sacramento River near Bend (RM 250), Red Bluff (RM 240), Freeport (RM 50), and Rio Vista (RM 30) in winter 2022.

Figure 5. Salmon salvage observed at Delta Fish Facilities in water year 2022.

American Shad – It is time to manage their populations

I have studied American shad, a popular sportfish and anadromous herring native to the East Coast, in the Hudson, Columbia, Sacramento, American, Feather, Yuba, and Stanislaus rivers. I have also fished for them for 50 years.  They are the most abundant anadromous fish in the Bay-Delta and Columbia River watersheds.  Millions run up the Sacramento and Columbia rivers every spring to spawn.  The 1-to-6-pound adults arrive in spring and spawn from late spring into summer as waters warm.  After spawning, some die, but many adults return to the ocean.   The eggs are large like those of salmon, but. unlike salmon eggs, shad eggs float and hatch as they drift downstream toward tidewater in the Delta through late spring and summer.  Young shad then rear in the tidal estuary through the summer before heading to the ocean.

Shad interact with our native fish in various ways, most of which are detrimental.  Whether they and other nonnative fish like striped bass contribute to population declines of native species like salmon, steelhead, smelt, and sturgeon is open to debate.  I believe that coupled with changes in climate and water management, the effects of nonnative fish on native species are getting worse.

A 2017 review of the ecological role of American shad in the Columbia River (Haskell 2017) provided three hypotheses regarding the Shad’s effect on Columbia River food webs:

  1. Juvenile shad are an abundant and highly energetic food that increase the growth rate of major salmon predators [e.g. Northern Pikeminnow, Walleye, Smallmouth Bass, and Channel Catfish) – viewed as negative by supporting production of salmon predators.
  2. Juvenile shad are planktivores that compete with juvenile salmon, particularly later migrating sub-yearling Chinook Salmon in the lower Columbia River – viewed as negative by reducing food for salmon thus reducing growth and survival.
  3. Large numbers of adult shad could influence nutrient balances given their capacity to convey marine-derived nutrients – another source of marine carbon input viewed as positive.

I would add four further hypotheses/issues on the role played by American shad:

  1. Adult shad migrate from the ocean into the Bay-Delta estuary in spring on their way to spawning rivers. They number in the millions, feeding on plankton including larval fish such as newly hatched Longfin and Delta smelt, and fry salmon that frequent the estuary and lower rivers.
  2. Adult shad spend late spring and most of the summer spawning in major in the mainstem rivers and their larger tributaries, during which they feed on aquatic invertebrates and juvenile salmonids. Their spawning run in the spring coincides with the rearing of juvenile fall-run salmon and steelhead.  Shad adults can be extremely abundant during the spring emergence of fry steelhead, especially in tailwaters below dams that block shad migrations.  The American, Feather, Yuba, and Mokelumne Rivers have such conditions.  Historical anecdotes of adult shad feeding on young salmonids below the Red Bluff Diversion Dam in the upper Sacramento River are available from CDFW predator survey reports.  In my own experience, I commonly use small spoons representing salmonid fry and parr size (2-3 inches long) that are readily swallowed by feeding adult shad.
  3. Adult shad may spawn through the summer in some tributary tailwaters where cold water releases (<65ºF) are prescribed for over-summering salmonids. Cold water can extend the period of shad spawning and the period in the tidal estuary when juvenile shad compete with smelt and other fishes for zooplankton prey.
  4. Juvenile American shad rear in freshwater and low-salinity tidal zones of the Bay-Delta estuary from late spring through summer (Figures 1-6), where they feed on zooplankton of the same types as Delta smelt and other native fishes.

As is the case with many native fish species, American shad populations suffer during periods of drought.  This has been especially true in the past two decades in the San Francisco Bay-Delta Estuary (Figure 7), commonly referred to as the period of the Pelagic Organism Decline.  It is an open question whether the American shad are simply experiencing the decline like the native fish, or contributing to the native declines, or both.

The likely answer is both.  All the fish suffer in drought.  All the fish do not recover completely after droughts.  All the fish populations exhibit a long-term downward population spiral.  For some, it is a spiral toward extinction.  Even in decline, some nonnatives like American shad and striped bass can have increasing effects on the natives facing extinction.  If that is the case, then we should do everything possible to at least provide habitat conditions that favor native fish over nonnative fish.  The fact is that, in many cases, nonnative fish, including shad and striped bass, are more resilient than the native fish.  That is because the physical habitat and water management increasingly are less favorable to the native species.  We need to reverse this trend.

For more recent discussion on Central Valley American shad see:

https://calwatercenter.org/american-shad-the-deltas-most-abundant-and-least-considered-anadromous-fish/

Figure 1. Wet year 2019 American shad juvenile catch-size distribution in Bay-Delta spring 20-mm Survey.

Figure 2. Wet year 2019 American shad juvenile catch-size distribution in Bay-Delta Summer Townet Survey.

Figure 2. Wet year 2019 American shad juvenile catch-size distribution in Bay-Delta Summer Townet Survey.

Figure 3. Wet year 2019 salvage and export rates of juvenile American shad at south Delta export facilities.

Figure 4. Wet year 2019 catch distribution of juvenile American shad in September Fall Midwater Trawl Survey.

Figure 5. Wet year 2019 American shad catch distribution versus salinity (EC) for September Fall Midwater Trawl Survey. Red line indicates shad concentrate in low-salinity zone (5-15k EC).

Figure 6. Wet year 2011 Delta smelt catch distribution versus salinity (EC) for September Fall Midwater Trawl Survey. Red line indicates smelt concentrate in low-salinity zone (5-15k EC).

Figure 7. Catch index of American shad juveniles in Fall Midwater Trawl Surveys 1967-2021. Recent drought periods noted.

Yuba River Salmon in 2022

In a December 2020 post, I described the status of the fall-run salmon population in the Yuba River.  Hatchery salmon predominate, while natural production is minimal.  The population remains in a very poor state – at about 10% of recent historical levels during and subsequent to multiyear droughts such as 2007-2009 and 2013-2015 (Figure 1).

In a January 11, 2022 post, the South Yuba River Citizens League (SYRCL) promotes cleaning the two fish ladders at Daguerre Dam half way up the river to the impassable Englebright Dam, in order to provide better passage for spawning salmon to prime spawning habitat.  Without effective ladders, salmon are delayed or even forced to spawn downstream of Daguerre Dam in marginal habitat.  The ladders must be maintained per the federal NMFS biological opinion and take permit to operate Daguerre Dam as a water diversion dam for the Yuba County Water Agency (YCWA).

SYRCL’s plea to clean the fish ladders is helpful in bringing attention to the problems facing salmon (and steelhead) in the lower Yuba River.  However, the fish ladders at Daguerre are only a small part of the problem for Yuba River salmon.  River flows and habitat in the lower Yuba River need improvement.

River Flows

It is instructive to compare flows in 2020 (Figure 2) to flows in 2021 (Figure 3), particularly at the Marysville gage, where water has passed downstream of all the local agricultural diversions at Daguerre Dam.

2020

From May through mid-August of 2020, flows at Marysville averaged about 1000 cfs (Figure 2).  The vast majority of this water was released through YCWA’s New Colgate Powerhouse upstream of Englebright Dam.  In the fiscal year from July 1, 2020 to June 30, 2021, YCWA had revenues from power sales of over $80 million. 1 Water released during the summer creates more power revenue than flows released in spring.

Better management for fish would release more of the water in the spring, providing more areas in the lower Yuba River for juvenile salmon and steelhead to grow and higher flows to move them downstream when they are ready to leave the system.  SYRCL, CSPA, and other conservation organizations, as well as staff from fisheries agencies, have recommended such a change in release pattern during the ongoing relicensing of YCWA’s hydropower project.

Some of this water released in the summer of 2020 was also sold out of the watershed, generally to entities south of the Delta.  In the fiscal year ending June 30, 2021, YCWA also made $12 million on water sales.2 The large flow increase at the end of August 2020 – likely a water sale – had no benefit for fish.  Its biggest effect on fish was that It drew down storage in New Bullards Bar Reservoir, which created a cascading effect in the very dry year 2021, when flows for all purposes were limited by lack of stored water.

2021

In a very dry year like 2021 that follows a dry year like 2020, river flows in spring and summer (Figure 3) become a major limiting factor.  First, there are no late-winter, early-spring flow pulses to attract adult spring-run salmon.  At a flow of 400 cfs at the bottom end of the lower Yuba River, there is insufficient flow to help adult spring-run salmon move upstream through many shallow riffles and through the Daguerre ladders.  Very low late-summer and fall low flows likewise hinder fall-run salmon.  Second, flows in late winter and early spring are too low to efficiently carry juvenile salmon downstream while avoiding the many predators on their way to the Bay and ocean.  Downstream of Daguerre Dam, over-summering juvenile salmon and steelhead must contend with low flows and associated stressful water temperatures.  Additionally, spawning at 400 cfs flow leads to redd scour if fall rainstorms occur: a late-October storm in 2021 brought Yuba flows up to 15,000 cfs and raised water levels nearly 10 feet (Figure 4).

Habitat

Feeding and cover habitat in the lower Yuba River are virtually nonexistent.  Predatory fish abound below Daguerre Dam.  Floodplain off-channel habitat and woody debris are severely lacking, especially during when winter-spring river flows are relatively low.  Many fall-run salmon spawn in poor spawning habitat below Daguerre.  To its credit, YCWA has contributed on a voluntary basis to several habitat improvement projects in the lower Yuba River, including the ongoing restoration at Hallwood.  However, it has vigorously resisted the establishment of regulatory requirements for additional projects.

Biological Opinion (BO)

Keeping the ladders clean is already a mandate.

  • Measures shall be taken by the Corps to minimize the effects of debris maintenance and removal at the Daguerre Point Dam fish ladders.
  • When Yuba River flows exceed 4,200 cfs, the Corps shall provide notifications to NMFS on the status of debris accumulations and fish passage conditions at the Daguerre Point Dam fish ladders.
  • The Corps shall take action within 24 hours, or as soon as it is safe, to remediate fish passage conditions related to debris maintenance and removal at the Daguerre Point Dam fish ladders.
  • The Corps shall, by January 31 of each year, report to NMFS an update on previous year’s debris maintenance and removal actions, including details on amount of debris removed, the timing of removal and the conditions that triggered debris accumulation.
  • The Corps should consider predator removal at Daguerre Point Dam.

 Summary and Conclusions

Flow regimes and habitat improvements are necessary to save Yuba salmon, in addition to ladder repairs and cleaning at Daguerre Dam.  The Yuba River Accord, which has defined lower Yuba River flows since 2008, leaves too much flow in the summer by shorting flows that salmon and steelhead need in the spring.  The channel of the lower Yuba River also needs extensive physical improvement.

Figure 1. Yuba River salmon escapement 1953-2020.

Figure 2: Yuba River flow (cfs) March 1 – September 15, 2020 above (orange) and below (blue)
Daguerre Dam.

Figure 3. Yuba River flow (cfs) March 15 – September 15, 2021 above (orange) and below (blue) Daguerre Dam.

Figure 4. River flow (cfs) and stage (feet) in lower Yuba River below Daguerre Dam near Marysville in fall 2021.

  1. See YCWA financial report for 2021 and 2020 at https://www.yubawater.org/Archive.aspx?ADID=310, pdf p. 14.
  2. Id. Compare wet year 2019, with likely no out of basin water sales, and water sale revenues of $531 thousand.

Delta Pumps Throttled Back – December 2021

A January 1 article in the Bee noted federal and state Delta pumping plants were “throttled back” in late December to protect the nearly extinct Delta smelt and other fish.  Exports had reached 9000 cfs from December 17-19, 2021, and then cut to 2000 cfs on December 20, despite high Delta inflows from the Sacramento River (Figure 1).  With the Delta Cross Channel closed in December and the False River Barrier in place, exports were drawing from the interior Delta via the Old and Middle River channels (Figure 2).  Most of that water was replaced via Georgianna Slough from the Sacramento River (7000 cfs) and San Joaquin River (1000 cfs).  The overall pattern from December 19 is shown in the map below.

Map of daily average flow conditions in the Delta, December 19, 2021.

Export cutbacks in December were prompted by the federal ESA biological opinions to protect Delta smelt, as well as winter-run and spring-run salmon from the Sacramento River.  Adult smelt move up into the interior Delta from the Bay with the first late-fall, early-winter runoff events.  Juvenile salmon move downstream to the Delta during these same early storm events and move into the interior Delta via Georgianna Slough.

Historically, exports were maxed-out near 11,000 cfs during December storm flows to refill San Luis Reservoir in the San Joaquin Valley after the irrigation season.  But such high exports resulted in heavy losses of smelt and salmon at the south Delta pumping plants (Figures 3 and 4), prompting the mandates in the biological opinions for export reductions.

San Luis Reservoir at the end of December 2021 was only at 30% of its 2 million acre-feet capacity; when the historical average for December has been 60%.  There is strong pressure to refill the reservoir.  On the other hand, the smelt and salmon are endangered species on the verge of extinction after several multi-year droughts in the past 15 years.  The smelt and salmon are in the Delta now, and need protection, whereas San Luis still has a chance of filling this winter under the allowed exports if 2022 continues normal or wet.  Because Federal and state laws mandate protecting the endangered fish and the biological opinions specify priority be given to the fish under these specific circumstances, export restrictions are the appropriate prescription.

Figure 1. Delta inflow from the Sacramento River at Freeport (FPT) and San Joaquin River at Mossdale (MSD) November-December 2021.

Figure 2. Internal Delta tidally-filtered flows in Old and Middle River en route to south Delta export pumps in December 2021.

Figure 3. Exports and salvage of winter-run salmon at export pumps from December 1, 2002 to February 1, 2003.

Figure 4. Exports and salvage of Delta smelt at export pumps from December 1, 2002 to February 1, 2003.