Whatever Happened to Adaptive Management?

The big hype over the past several decades in the Central Valley has been Adaptive Management.  Whatever happened to it?  Did we forget about it, or simply take it for granted?  Did we rebrand it, morph it into something else?  I wrote a “white paper” on the topic for CALFED over 20 years ago.  My version was more about conducting experiments to address unknowns to help inform management decisions.

The definitions immediately below are further refinements.

Adaptive management, also known as adaptive resource management or adaptive environmental assessment and management, is a structured, iterative process of robust decision making in the face of uncertainty, with an aim to reducing uncertainty over time via system monitoring.

Above definition from Wikipedia

Adaptive management is a science-based, structured approach to improving our understanding of the problems and uncertainties of environmental and water management. (Older)

Adaptive management provides a structured approach for adaptation in a context of rapid, often unprecedented, and unpredictable environmental change. Its success depends on support from the larger social, regulatory, and institutional context, or “governance system.”   (Newer)

Above definitions from Delta Stewardship Council

The Delta Stewardship Council holds a forum every two years on Adaptive Management.  This year, the forum delves into governance.  Presenters and participants are from Delta governments and those who would like to participate in Delta government.  Topics include equitable adaptation, governance systems and needs, and human dimensions of adaptation and governance. 

While that all is nice, it is not what I am looking for to manage the Delta ecosystem.  I am more for the older definition.  We need answers.

Why are the Sacramento River and Delta so warm in the past decade or so?  Is it all climate change, drought, and air temperatures?  What has changed, and what can be done about it?  Those are my questions.  We need more adaptive management questions and some scientific experiments and monitoring.  I have analyzed much of the available data and developed theories on causes (with supporting data and analyses), but theories need testing through controlled scientific study that can lead to effective changes: adaptive management.

My theory is that we need 5000 to 10,000 cfs streamflow in the Sacramento River to keep it cool in summer.  We need to test that theory to find out how much water is really needed, and how much, when, and where under highly variable air temperatures.

Water managers have consistently opposed this kind of experiment.  They refuse to use the water for this kind of experiment.  And more importantly, they refuse to do an experiment that might produce the answer they don’t want to be known, let alone supported by rigorous study: more flow is needed.

On the contrary, there is a constant, built-in bias towards “experimenting” with how little water one can use to achieve biological objectives.  If too little water won’t achieve the desired outcome, managers, and in some cases scientists, try modifying the threshold biological objectives.

56oF was supposed to be fine for salmon spawning near Redding.  In 2021 and 2022, agencies including Reclamation thought they could get away with 58-60oF for periods (they couldn’t, Figure 1).  It turns out from controlled experiments that 56oF was too warm – 53oF is needed to keep eggs alive and well in the gravel.  There is simply no getting around it.  The agencies were experimenting with critically endangered salmon with poorly designed, un-scientific management strategies.

In the Vernalis Adaptive Management Program in the early 2000s, ten years of experimenting found that relatively small increments of flow increase in the San Joaquin River from mid-April through mid-May, combined with minimum Delta exports by the state and federal water projects, did not dramatically increase survival of San Joaquin River juvenile salmon migrating downstream.  The “adaptive” element of adaptive management did not thereafter increase the flows to see if that would improve juvenile survival.  On the contrary, water managers declared that more flows don’t help, and the Bureau of Reclamation since 2011 has serially ignored the flow requirements and export restrictions in mid-April through mid-May to which the rules were supposed to revert after the “experiment” concluded.

Here are some further questions that are begging for controlled scientific experiments, associated monitoring, and adaptive action:

What will it take to keep the spring-summer Delta water temperature in key areas (such as the low salinity zone) below 72oF, at least through spring (Figure 2)?

Is there something we can do to keep the Bay cooler in summer (Figure 3)?

There is little doubt that improving these temperatures would improve conditions for fish.  But the scientific community needs to push itself and water managers past built-in biases in order to evaluate the feasibility of such improvements.

Figure 1. 2021 and 2022 water temperatures in the Sacramento River above the mouth of Clear Creek near Redding. Red Line is safe level for salmon eggs.

Figure 2. April-June water temperatures in Sacramento River at Freeport in the north Delta in spring in past decade. Yellow line is critical level 68oF for migrating juvenile and adult salmon.

Figure 3. Water temperatures at the Benicia Bridge at the west end of Suisun Bay, 1998-2023. Red line is critical level for salmon survival during migration.



Yuba River – Plan for New Fish Facilities at Daguerre Point Dam

On May 16, 2023, the California Department of Fish and Wildlife, National Marine Fisheries Service, and Yuba Water Agency announced a plan to design and build a fish bypass at Daguerre Point Dam on the lower Yuba River (see Figure below).

At present, the dam has fish ladders on both ends of the dam that don’t work well.  The plan’s conceptual design is for a bypass channel that would allow fish to circumvent the existing dam; the plan would retain the dam.  The plan would reconfigure the diversion works at the dam’s south end and add effective fish screens to the agricultural diversion infrastructure at both ends of the dam.

Essentially, the bypass would operate as a long, high-capacity fish ladder that would also allow passage of sturgeon and lamprey, which cannot use the existing fish ladders.  In addition to improving the upstream migration of adult fish, the bypass would also allow for more natural downstream passage of juvenile fish.

For adult salmon and steelhead migrants headed upstream to spawn in the higher-flow, cooler, and gravel-abundant 10-mile reach between Daguerre Point Dam and Englebright Dam, the bypass would likely reduce delays caused by reluctance to enter the existing ladders and by the difficult ascent up those ladders.  For juveniles outmigrating downstream, the bypass could offer more natural conditions than simply spilling over the dam or seeking out the openings to the two ladders and passing downstream in the ladders.  The existing features place the young fish at the mercy of native and non-native fish predators below the dam.

The bypass concept is one of several designs that could reduce existing problems at Daguerre.  In addition to passage improvement, the concept could accommodate fish collection and segregation, and may be a feasible location for a conservation hatchery.

Several key elements should be added to this bypass plan, including:

  1. A segregation weir that that allows selective passage and capture of upstream and downstream migrants for processing and transfer.
  2. Predator removal, either at the segregation weir or by means of another nearby arrangement, to minimize predation below the dam. Predator control would likely benefit the entire lower Yuba system.  Major predators in terms of numbers and threat below Daguerre Dam include striped bass, smallmouth bass, pikeminnow, and American shad.
  3. Stream habitat improvements upstream, in the bypass, and below the dam, in particular those that create refugia for juvenile salmon, steelhead, and sturgeon, and that are less favorable to the fish that eat them.
  4. Fish handling, processing, and holding facilities.
  5. A conservation hatchery for salmon and steelhead.

Alternative designs should also be fully evaluated through CEQA/NEPA and CESA/ESA processes.  For example, one alternative may involve upgrading one or both of the existing ladders to include as many of the advantageous features as possible.


Salmon Have Already Been Compromised in Wet 2023

Warming water in the Sacramento River in late April compromised salmon as rains diminished and Central Valley water managers captured snowmelt for storage and irrigation. The water warmed as wild juvenile salmon and 20 million or so hatchery smolts moved down the Sacramento River toward the ocean, and as adult winter-run and spring-run salmon migrated up the river.

Water temperatures increased despite a clear trajectory toward full reservoirs (Figure 1). Water temperatures at Wilkins Slough rose nearly 10oF in late April to the low 60’s, while flows dropped from March flows of 25,000 cfs to only 12,000 cfs during the April hot spell (Figure 2). Though prescribed small flow pulses from Shasta Dam1 (Figure 3) and cool weather (Figure 4) reduced thermal impacts in early May, that was not true for the end of April.

Allowing flows to drop and water temperatures to rise in the last half of April was irresponsible and easily avoidable. Releases from storage to keep the river cool would not have even come close to preventing Shasta from filling. The goal for the lower Sacramento River to minimize stress on migrating juvenile and adult salmon in a wet year like 2023 should be water temperatures below 60oF (Figure 5).

Water managers need to manage for fish at the same time they manage for water supply, not as an afterthought. In a year of abundant water, active management for fish is not that hard and has no water cost. Even in less bountiful water years, the mindset and bias of filling before releasing requires adjustment.

Figure. 1. Shasta has dramatically filled this spring.

Figure 2. Streamflow and water temperature in the lower Sacramento River at Wilkins Slough in 2023.

Figure 3. End of April flow pulse from Keswick Dam near Redding.

Figure 4. Air temperatures at Red Bluff in 2023.

Figure 5. Interagency water temperature prescriptions for salmon recovery from the San Joaquin River Salmon Recovery Program.

California Needs a Wild Salmon Policy

Canada has a Wild Salmon Policy. California needs one. California can develop a better salmon policy by taking a good look at the Canadian policy.

In past posts, I have mentioned the need for a comprehensive California Salmon Plan.1 There are many plans in California, but there are few with real actions like NOAA Fisheries (National Marine Fisheries Service – NMFS) Central Valley Salmon Recovery Plan. The problem is that most plans have no “bite.” NMFS has been given a “bite option” in issuing take permits under the Endangered Species Act, but NMFS rarely uses its full authority in issuing biological opinions for federal projects. NMFS is particularly averse to issuing “jeopardy” opinions with mandated Reasonable Prudent Alternatives (RPAs).

Canada’s Wild Salmon Policy2

“Wild salmon hold tremendous value for natural ecosystems, cultural and spiritual practices, jobs and income, and recreational enjoyment along the coast and inland watersheds of the Pacific Region. They are important for Indigenous people, communities, individuals, groups and businesses.” (Policy, p. 5).

The value of California’s wild salmon public trust resources needs more consideration and recognition. For example: in setting rules for commercial and recreational harvest of the dominant fall-run Chinook salmon stocks, little or no consideration is given to protecting dwindling wild fall-run salmon populations.

While Canada’s Wild Salmon Policy is not exactly a plan with specific actions (the Policy leaves that to local and regional entities), the Policy does outline goals, objectives, strategies, approaches, and what might be called overarching concerns. Chief among the Wild Salmon Policy’s overarching concerns that also apply to California salmon are:

  • Diversity – There were once many salmon stocks located within and among the many rivers and tributary streams in the Central Valley. Preserving this genetic diversity deserves much more consideration.
  • Keystone species – Maintaining the role of salmon that were once important to the entire ecosystem, bringing in marine nutrients and carbon to watersheds, is important.
  •  Declines in specific populations – There is a need to immediately address sudden or unforeseen drops in abundance of any population or subpopulation.
  • Ocean and river conditions – There is a need to recognize and react to sudden or unforeseen changes in habitat conditions that have potential adverse impacts to salmon.
  • Less predictable returns – Accurate predictions are real problems for fishery managers; poor predictions are the norm.
  • Reduced available stocks for harvest – There is a need to anticipate and address stock collapses before and after they occur through aggressive planning and an array of actions; lower fishable stocks threaten traditional uses of public trust resources like salmon.

Canada’s Wild Salmon Policy has three main strategies:

  1. Involve stakeholders – Stakeholders have unique and important knowledge about Pacific salmon, how the local environment functions, and characteristic ecological relationships.
  2. Develop technical methods and tools – To support the status assessment of salmon conservation units, there must be initiatives to assess habitat and ecosystems, and day-to-day fishery and ecosystem management decisions within regional programs that reflect the principles, goals, and objectives of an overall wild salmon program.
  3. Develop and implement a comprehensive management plan – Canada uses a comprehensive plan with a five-year implementation plan and an annual-review process. (Note: the latest 5-Year Winter-Run Salmon Plan in California was dated 2016.)

The general approach of Canada’s Wild Salmon Policy is:

  • Engage partners and stakeholders at the local level to leverage local knowledge and expertise.
  • Facilitate collaboration through salmon governance processes and capacity building.
  • Consider guiding principles and objectives in ongoing management and program activities, both internally and with partners.
  • Adapt and update best practices based on lessons learned.

The strategies for and approaches to assessment in Canada’s Wild Salmon Policy are:

  • Standardized monitoring of wild salmon – To understand the current status of wild salmon stocks, it is important to have regular, standardized, science-based monitoring that identifies benchmarks for Conservation Units (CUs).
  • Determine the current status of Conservation Units.
  • Continue to monitor and assess status of Conservation Units.
  • Set Priorities – Implement prioritization method for assessing and monitoring Conservation Units or groups of Conservation Units.
  • Modify or develop metrics and document new status assessment methods.
  • Consolidate and improve documentation of standards for internal and external monitoring programs and improve data sharing through open processes.
  • Consider guiding principles and objectives in planning annual and multi-year work processes.
  • Continue integrated planning discussions through various mechanisms, including local roundtables.
  • Work on an integrated approach to wild salmon.

The delineation of Conservation Units and their benchmarks does not prescribe specific management actions, but rather is used to inform decision-making. As spawner abundance (escapement) decreases, a Conservation Unit moves towards a lower status, and the extent of management intervention for conservation purposes increases. A low Conservation Unit index is undesirable because of the risk of extirpation and the loss of ecological benefits and salmon production. Changes in status should trigger management actions, which will vary depending on species, geographic regions, and cause of the decline.

The implementation Plan of Canada’s Wild Salmon Policy involves:

  • Assessment of impacts and monitoring habitats.
  • Accountability in completing actions and reporting.
  • Maintaining and rebuilding salmon populations.

In conclusion, Canada’s Wild Salmon Policy provides a good model for a badly needed comprehensive Central Valley Salmon and Steelhead Protection and Recovery Plan or Program, for the entire array of federal and state salmon and steelhead projects that are undertaken in the Central Valley. It should encompass planned and ongoing projects funded by the departments of the Interior, Commerce, Agriculture, Defense, Energy, and by the EPA, as well as those jointly permitted by the California Resources Agency.

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: