Category Archives: Chinook Salmon

Sacramento Valley Salmon Resiliency Strategy

Posted on by

The Sacramento Valley Salmon Resiliency Strategy, June 2017, is the state’s strategy to improve the resilience of listed salmon to its activities, including water rights permits, State Water Project actions, CESA implementation, and CDFW management.

The document states on page 2:

Specific biological objectives have been identified for the Sacramento River that support the general need to increase survival and productivity of salmonids in the Sacramento Valley and to increase life history and genetic diversity. A summary of these biological objectives:

  1. Increase productivity by improving spawning and incubation conditions (habitat and water quality).
  2. Increase productivity by increasing juvenile salmonid survival.
  3. Support the full range of juvenile migration conditions to maintain life history diversity.
  4. Support the full range of adult migration conditions to maintain life history diversity.
  5. Maintain genetic integrity by limiting genetic influence from hatchery-produced fish and interbreeding of genetically or behaviorally distinct runs.

The Strategy is an aggressive approach to improving species viability and resiliency by implementing specific habitat restoration actions. (Emphasis and bullet numbering added)

The Strategy is defined as a “resiliency” strategy and not a recovery strategy for a reason. It does not include the actions necessary for recovery. It won’t fix the activities that caused the crisis in the first place. Over the past several decades, much restoration has occurred, yet fish populations continue to decline. Much stronger and more immediate management actions are needed to save the salmon populations. Habitat restoration alone will simply not suffice.

So what is missing?

  1. Spawning and incubation conditions – Missing are actions to maintain cold water temperatures and sufficient spawning flows in the reaches below all the major dams during spawning and incubation. A. Eliminate the water temperature increases caused when water from Whiskeytown Reservoir is routed through Spring Creek Powerhouse to Keswick Reservoir. B. Maintain cold water in the Sacramento River downstream to Red Bluff, not just to Redding. C. Eliminate dewatering of winter, spring, and fall–run salmon redds in the Sacramento River. D. For the American and Feather rivers, take actions similar to A through C that maintain cold water and eliminate redd stranding. E. Better manage reservoirs to place more emphasis on cold water pools and less on water deliveries.
  2. Juvenile salmon survival – Maintain adequate flows and water temperatures in rearing reaches to sustain growth and to reduce stress and predation.
  3. Full range of juvenile migration conditions – Maintain adequate flows and water temperatures in the lower rivers and the Delta throughout emigration seasons. Do not shave off early and late seasons.
  4. Adult migrations – Maintain adequate flows and water temperatures to assure adult survival, egg survival and gonad development during migration. Do not shave off early and late seasons.
  5. Genetic integrity – Move more toward conservation hatchery activities, reduce straying by barging smolts, implement natural floodplain rearing, mark all hatchery smolts, and introduce mark-selective recreational fisheries.

As for other planned actions like completing projects on Battle Creek and reintroducing salmon upstream of Central Valley rim reservoirs, let’s get on with it. If we keep the present snail’s pace, there is little hope for future salmon generations.

Winter-Run Salmon Status – 2018

Posted on by

In a March 14 post, I discussed the primary factor in the initial decline of Sacramento River winter-run salmon in the early 1980s (Figure 1) – higher south Delta exports in drier years after the State Water Project came on line in the 1970s.   In a January 15, 2017 post, I discussed the causes of the recruitment failures from poor egg survival in spawning grounds in summers of 2014 and 2015.  In this post, I suggest that recruitment into the population and long-term population declines stems from fewer spawners (eggs produced) over time and low Sacramento River flows (Shasta Reservoir releases) in fall and winter.

The spawner-recruit relationship (Figure 2) depicts a strong positive effect of the number of spawners on the number of recruits into the population.  This is important because mortality reduces the number of spawners and also the subsequent years’ egg production – a double whammy.  Without mitigation, the population spirals toward extinction.

In addition, the relationship suggests that ten times as many salmon are produced in wetter years as in dry years for the same level of spawners.  Over the past decade, drier years have lower fall and winter river flows in the upper river spawning and early rearing reach (Figure 3), and lower winter flows in the lower river rearing and migratory reach (Figure 4).  The lower fall-winter flows reduce the productive capacity and survival of young salmon in the upper river spawning-rearing reach.  The low winter flows in the lower river reduce transport and survival on the way to and through the Delta.

The road to recovery is to build up the number of spawners by providing better flows in fall and winter, and to ensure eggs are sustained by cold-water Shasta Reservoir releases through the summer.  Hatchery augmentation helps sustain existing low levels of adult spawners in the population; otherwise the population would decline toward extinction in fewer generations.

Figure 1. Spawning population estimates of adult winter-run salmon in the upper Sacramento River from 1974 to 2017. Source: CDFW.

Figure 2. Spawner-recruit (log-log) relationship for the winter-run salmon population in the Sacramento River. The number is the brood year. For example: 1991 depicts the recruits derived from 1991 spawners. Red represents drier years, and blue represents wetter years for the brood year’s first summer and fall. For example: 1991 was a dry year.

Figure 3. Daily average Sacramento River flow below Keswick Dam, 2007-2018. The 54-year average median daily flow is also shown. Source: USGS.

Figure 4. Daily average lower Sacramento River flow at Wilkins Slough, 2008-2018. The 54-year average median daily flow is also shown. Source: USGS.

More on Sacramento River Salmon Declines Reclamation did what it had to do in water years 2010 to 2012, but not in 2016-2018.

Posted on by

With poor salmon runs from 2009 to 2011, Reclamation provided good conditions in the lower Sacramento River below Shasta Reservoir in spring-summers of 2010 to 2012 for fall-run and winter-run salmon. That effort contributed to recovery of fall-run salmon from the 2007-2009 drought in 2012-2014 (Figure 1). The sequence of below-normal, wet, and below-normal water years (2010-2012) provided sufficient water for good smolt survival, overcoming a significant deficit of adult spawners (eggs spawned). Poor conditions in the subsequent drought of 2013-2015 led to the latest fall-run collapse in 2016-2017.1

So did Reclamation provide good spring-summer conditions in the lower Sacramento River in below-normal, wet, below-normal water year sequence 2016-2018 to help recovery from the latest drought? No. As a result, we can now expect poor runs in 2019 and 2020 instead of a recovery.

2010-2012

Reclamation made a concerted effort in 2010-2012 to meet water temperature objectives in the upper river near Red Bluff (Bend, Balls Ferry, and Red Bluff) and the lower river near Sacramento (Wilkins Slough, Verona). The 56°F and 68°F water temperature objectives for the upper and lower river, respectively, were regularly met (Figures 2-4) in spring and summer.

2016-2018

In a less than concerted effort in 2016-2018, Reclamation has failed to meet the water temperature objectives more often and with greater discrepancies (Figures 5-7). More detail on the failure is provided in a recent post.

Problem and Solution

The causal factor is simply lower flows in spring and summer 2016-2018 than 2010-2012 (Figure 8). Lower flows, higher water temperatures, and lower turbidities lead to poor salmon smolt survival (and low adult migrant survival and subsequent egg viability). A concerted effort to recover salmon would mean maintaining water temperature objectives with spring-summer flows in the lower river at Wilkins Slough in the 7000-8000 cfs range instead of the 5000-6000 cfs range (Figure 8). This may require a supplemental release from Shasta Reservoir as in 2012 (Figure 9), which amounted to nearly 200,000 acre-ft of storage release, so that storage ended at 2,600,000 acre-ft at the end of September. The target end-of-September storage in below-normal water year 2018 is 2,300,000 acre-ft. With water deliveries near 2 million acre-ft from the Sacramento River in 2012 and 2018, a “concerted effort” involving 200 thousand acre-ft to maintain water temperature objectives prescribed in the water right permits seems reasonable. Whether it comes from Shasta storage or water contractor deliveries is a management/permitting agency decision.

Figure 1. Long-term trend in upper Sacramento River fall-run salmon escapement. Red circle denotes recovery from low escapement from 2007-2009 drought.

Figure 2. Water temperature in the upper (Red Bluff, Balls Ferry) and lower Sacramento River (Verona) in 2010. Top red line denotes objective for lower river (68°F); bottom line denotes objective for upper river (56°F). Red circle denotes excessive temperatures. In 2010, a below-normal water year following three years of drought had water temperatures near objectives.

Figure 3. Water temperature in the upper (Red Bluff, Balls Ferry) and lower Sacramento River (Verona) in 2011. Top red line denotes objective for lower river (68°F); bottom line denotes objective for upper river (56°F). In 2011, a wet water year had water temperatures near objectives.

Figure 4. Water temperature in the upper (Red Bluff, Balls Ferry) and lower Sacramento River (Verona) in 2012. Top red line denotes objective for lower river (68°F); bottom line denotes objective for upper river (56°F). Red circles denote excessive temperatures. In 2012, a below-normal water year following a wet year had water temperatures near objectives.

Figure 5. Water temperature in the upper (Red Bluff, Bend, Balls Ferry) and lower Sacramento River (Wilkins Slough, Verona) in 2016. Top red line denotes objective for lower river (68°F); bottom line denotes objective for upper river (56°F). Red circles denote excessive temperatures. In 2016, a below-normal water year following three drought years had water temperatures exceeding objectives April through July.

Figure 6. Water temperature in the upper (Red Bluff, Bend, Balls Ferry) and lower Sacramento River (Wilkins Slough, Verona) in 2017. Top red line denotes objective for lower river (68°F); bottom line denotes objective for upper river (56°F). Red circles denote excessive temperatures. In 2017, a wet water year had water temperatures exceeding objectives May through August.

Figure 7. Water temperature in the upper (Red Bluff, Bend, Balls Ferry) and lower Sacramento River (Wilkins Slough, Verona) in 2018. Top red line denotes objective for lower river (68°F); bottom line denotes objective for upper river (56°F). Red circles denote excessive temperatures. In 2018, a below-normal water year following three drought years had water temperatures exceeding objectives April through June.

Figure 8. Summer flow in the lower Sacramento River (Wilkins Slough) in 2010-2012 and 2016-2018.

Figure 9. Releases of water from Keswick Reservoir to the lower Sacramento River in 2012 compared to 54 year average.

Gross Violation of Water Quality Standards for Water Temperature in Lower Sacramento River Further Degradation of Salmon Habitat

Posted on by

Water temperatures in the lower Sacramento River over the past month have often exceeded water quality standards that protect salmon and other beneficial uses (Figures 1 and 2).  Water temperatures at or above the standard of 68oF adversely affect adult and juvenile salmon.  Water temperatures can meet the standard if the Bureau of Reclamation maintains flow in the Sacramento at Wilkins Slough at 6000-8000 cfs, depending on air temperature.  The Bureau of Reclamation has maintained such flows in the past to meet water quality standards and terms in its water rights permits (Figure 3).  Shasta Reservoir water storage is 102% of normal as of June 18, 2018.  Water diversions from the Sacramento River upstream of Wilkins Slough are approximately 6,000 cfs, with 100% allocation to CVP contractors under water right permits.  For more on the effects on salmon, see past posts.

Figure 1. Sacramento River flow and water temperature at Wilkins Slough in lower Sacramento River: mid-May to mid-June 2018. Red line denotes water quality standard. Source: CDEC.

Figure 2. Sacramento River water temperature at Verona in lower Sacramento River: mid-May to mid-June 2018. Red line denotes water quality standard. Source: CDEC.

Figure 3. Historical and recent flow at Wilkins Slough. Source: USGS.

2016-2017 Salmon Crash
Sacramento River Fall-Run Salmon Decline

Posted on by

In an April 2018 post, I revisited the 2007-2009 salmon crash and warned of the current 2016-2017 crash.  In an April 2017 post, I opined on the status of population and its future given the population crashes.  In this post, I update the population data with preliminary estimates of the 2016 and 2017 runs, including (1) the in-river estimate from the spawning grounds between Keswick Dam and Red Bluff (Figure 1), and (2) Coleman National Fish Hatchery (CNFH) and Battle Creek (Figure 2).

I developed a stock-recruitment relationship using the in-river data shown in Figure 1.  A plot of the population-produced from spawners three years earlier (Figure 3) shows extremely poor runs for 2016 and 2017, given the number of parental spawners three years earlier.  The red numbers reflect drought conditions winter-spring of 2014 and 2015, when these broods were rearing and migrating in the Sacramento River in the first few months of their lives.  The earlier posts covered the factors that led to poor survival in the drought years.

Forecasts for the 2018 run are mixed.  Higher jack numbers in the 2017 run likely foreshadow improvements in the adult 2018 run.  Based on the Figure 3 relationships, the higher 2015 run, along with normal year conditions (a green number) for winter-spring 2016 compared to 2014 and 2015, would also indicate an improved run for 2018.   A forecast for 2019 and 2020 runs, given the poor runs in 2016 and 2017, is risky at best, despite reasonably good winter-spring conditions in 2017 and 2018 compared to drought years 2014 and 2015.  A lack of recovery to 2015 spawner levels in the fall 2018 run would be a serious concern.

Figure 1. Run size estimates (escapement) of fall-run Chinook salmon from spawning grounds in the upper Sacramento River between Keswick Dam and Red Bluff from 1975 to 2017.

Figure 2. Run size estimates (escapement) of fall-run Chinook salmon from the Coleman National Fish Hatchery on Battle Creek near Red Bluff from 1975 to 2017.

Figure 3. Spawner-recruit relationship for fall-run in-river estimates of run size from Figures 1 and 2. Number indicates spawner estimate for that year (y-axis) as derived from spawners three years earlier (x-axis). Color indicates winter-spring rearing-migration conditions for that brood (winter-spring 2015 for spawners in 2017). Red denotes dry year in first winter-spring. Green is for normal years. Blue is wet years.