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Basics
Thriving Species and Food Web
Salmon
Indicator
Number of natural-origin Chinook salmon on spawning grounds
Vital Sign Indicator
Each Unit (number)
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By 2050, all Chinook salmon populations increase, and at least 50 percent of the populations reach their recovery goals.

Target fact sheet 

Neala Kendall
Contributing Partners
Last Updated
5/23/2022 12:15:44 PM
Map
Chinook salmon population spawner abundance relative to planning targets designated by NOAA Fisheries for each population in Puget Sound. The map shows each population's five-year (2015-2019) geomean of spawner abundance as a percentage of the low productivity planning target (5-year geomean/low productivity planning target)*100). Thus, the map shows which populations are further away (smaller numbers) vs. closer (larger numbers) to their recovery planning targets.
Description
This indicator evaluates the abundance values and their trends of the 22 Chinook salmon populations from five Puget Sound regions as measured by the number of natural-origin adult fish on the spawning grounds. Abundance estimates here do not include hatchery-origin fish (with few exceptions) or Chinook taken in harvest or by predators like orcas. The indicator is intended to reflect the goal of achieving wild population recovery of Puget Sound Chinook, which are federally listed as threatened.
Vital Sign Indicator Chart
Annual percent change in Chinook salmon population spawner abundance from 1999 to 2019 for each Puget Sound population, shown by geographic region. The lines show the 25th to 75th Credibility Intervals (CIs). These represent a range of values the true annual percent change likely falls within. All CIs contain zero meaning no change in spawner abundance over the time period is possible for all populations.

Chinook salmon are a cultural icon of the Pacific Northwest and are listed as “Threatened” under the federal Endangered Species Act (ESA); currently they are about one-third as abundant as they were in the early 1900s. Returning Chinook are highly prized by anglers and commercial fisherman, are guaranteed to be available to Indian Tribes by treaties signed with the federal government, and are a favorite food of orca whales. 

Key Vital Sign Indicator Results
  • There is little to no sign of recovery of Puget Sound Chinook populations in each biogeographic region. On the other hand, the majority of populations have not decreased significantly in abundance since the time Chinook salmon were listed as threatened under the ESA in 1999. Therefore, our conclusion about progress of the populations of Puget Sound Chinook salmon is “Not Improving”.
  • Estimates of population spawner abundance of the 22 Puget Sound Chinook populations have changed very little since the baseline reference period when the populations were listed in 1999.
  • While most populations remain far below their recovery planning targets adopted by NOAA Fisheries, some are doing better. For instance, the recent 5-year abundance geomean for Suiattle River spring Chinook salmon is at 103% of its low productivity planning target for abundance. Upper Sauk River spring Chinook salmon and Upper Skagit River summer Chinook salmon are at 43% and 37%, respectively, of their low productivity planning targets.
  • The Puget Sound Partnership 2020 recovery target to stop the overall decline in Puget Sound Chinook salmon abundance has been met; however, the recovery target for improvements in wild Chinook abundance across biogeographic regions has not been met.
Methods
Monitoring Program

Chinook salmon spawner abundance data are collected annually by WDFW and tribal co-manager staff as part of baseline monitoring and data collection efforts.

Data Source

Washington Department of Fish and Wildlife (WDFW), Salmon Population Indicators (SPi) abundance data

Northwest Fisheries Science Center. 2015. Status review update for Pacific salmon and steelhead listed under the Endangered Species Act: Pacific Northwest.

Annual total spawner abundance is typically estimated by counting the number of redds (gravel nests) in a river. Redds are counted by walking the stream or from boats or aircraft. In many populations, some hatchery-origin salmon are present on the spawning grounds along with natural-origin salmon, complicating the estimates of natural-origin abundance. The proportions of spawners that were of natural versus hatchery origin are typically estimated based on the composition of carcasses of each origin. These values are applied to the total spawning population to estimate the number of natural-origin versus hatchery-origin spawners.

Chinook salmon population spawner abundance is reported here as the number of natural-origin fish estimated on the spawning grounds for all populations except in the Skagit River basin, where total spawner abundance is reported. Natural-origin, naturally-spawning fish abundance data are not currently available in WDFW's SPi database for the Suiattle, Cascade, Upper Sauk, Lower Sauk, Upper Skagit, and Lower Skagit populations. However, the proportion of hatchery-origin, naturally-spawning fish in these populations is expected to have been relatively low (e.g., < 5 percent) consistently since 1999 based on information and estimated values in the Marblemount Hatchery Spring Chinook Hatchery and Genetic Management Plan (HGMP) and that hatchery's Summer Chinook HGMP. Thus, we chose to use the available data for total number of naturally-spawning Chinook salmon in these analyses. We will continue to try to gather natural-origin, naturally-spawning Chinook salmon abundance data from these populations for future analyses.

Our analysis of abundance change over time answers the question: has the spawner abundance of each Chinook salmon population changed compared to when they were listed by NOAA Fisheries under the Endangered Species Act (ESA) in 1999? We chose ESA listing in 1999 as the baseline reference period because this date denotes the start of deliberate management effort to improve the status of the population. It should be noted that the 1999-2003 period was one of relatively favorable ocean conditions (i.e., a “cool” PDO phase) for Puget Sound Chinook salmon, where we would expect better marine survival than during a warm PDO phase.

In this trend evaluation, we fit a multivariate autoregressive state space random walk with drift (MARSS-RWD) model to the log of population spawner abundance data for all populations from 1999 to 2019. The model structure was identical to that used by NOAA Fisheries’ Northwest Fisheries Science Center in its 5-year status review with a few exceptions (Northwest Fisheries Science Center, 2015). The slope of each population's smoothed abundance values was converted to percent change per year. If data were not available during these periods for a given population, data from the first or most recent years with available data were used.

To assess each population’s spawner abundance levels, we compared their recent 5-year geometric mean (“geomean”) of smoothed abundance data from the MARSS-RWD model to their low productivity planning target for abundance to get a percent of target abundance. Planning targets for Chinook abundance have been estimated for both low and high productivity scenarios. At low productivity, the population needs to be larger compared to that at high productivity in order to survive and be resilient to poorer habitat and environmental conditions, changes, and catastrophes. We evaluated the recent 5-year geomeans relative to the low productivity planning targets because the populations are thought to be in a low productivity phase and it is a more conservative assessment. Find more information on Chinook planning targets for abundance and productivity in chapter four of the “Technical Recovery Criteria and Goals for Puget Sound Chinook Salmon of the Puget Sound Salmon Recovery Plan (2007).” Please note that the planning targets for abundance were adopted by NOAA Fisheries and are distinct from the Vital Sign indicator 2020 recovery target.

For more information about the methods used for this indicator, please see the Status and Trends Analysis of Salmon Abundance Data methods report.

References:

Northwest Fisheries Science Center. 2015. Status review update for Pacific salmon and steelhead listed under the Endangered Species Act: Pacific Northwest.

National Marine Fisheries Service, Shared Strategy for Puget Sound. 2007. Puget Sound Salmon Recovery Plan, Volume 1.

Critical Definitions
  • Natural-origin fish: fish produced by parents spawning in natural environments (not in a hatchery)
  • Natural-origin adult fish on the spawning ground: fish produced by parents spawning in natural environments that themselves returned to spawn in a natural environment
  • Population spawner abundance: number of natural-origin Chinook salmon estimated on the spawning grounds in a population (for instance, the North Fork Nooksack)
  • Hatchery-origin fish: fish produced by parents spawned in a hatchery
  • Endangered Species Act (ESA): Puget Sound Chinook salmon were listed as Threatened under the ESA in 1999. There are 22 NOAA Fisheries-defined distinct independent populations (DIP; generally known as “populations”) in the Puget Sound Chinook evolutionarily significant unit (ESU)
  • MARSS-RWD: multivariate autoregressive state space random walk with drift model, which was the statistical model used in our analyses
Interpretation of Results

The majority of Puget Sound Chinook salmon populations are currently well below abundance levels (planning targets) needed for population recovery and reduced risk of extinction (Table 1). Population spawner abundance values fluctuate from year to year, often with no clear linear trends. To visualize the year–to-year adult abundance estimates and the data underlying our results, please consult the fish abundance information compiled by the Washington Department of Fish and Wildlife and report in the State of the Salmon.

NOAA Fisheries is the federal agency responsible for the recovery of ESA-listed salmonid species. They report trends as part of their status reviews every 5 years. In their most recent available status review (Northwest Fisheries Science Center, 2015), they analyzed the 15-year trend over a continuous time period from 1999 to 2014 using a similar model employed for the time trend analysis described in the methods section above. NOAA Fisheries found that the natural-origin spawner abundance of four Chinook salmon populations increased, six had no trends, and 12 decreased (statistically significant changes) over the 1999 to 2014 time period. Because fewer populations had negative trends in an earlier period (1990-2005), they concluded “there is a general decline in wild spawner abundance across all MPGs [major population groups; a subset of an ESU containing a various group of populations] in the recent fifteen years”.

Table 1. Geometric mean (geomean) of model-smoothed Chinook salmon spawner population abundance (2015-2019) and planning targets of each Puget Sound population.
Geographic Region Population Name 2015-2019 Geomean Planning Target Geomean % of Low Prod. Planning Target*
High Productivity Low Productivity
Strait of Georgia NF Nooksack 112 3,800 16,000 1%
SF Nooksack 85 2,000 9,100 1%
Strait of Juan de Fuca Elwha 114 6,900 17,000 1%
Dungeness 103 1,200 4,700 2%
Hood Canal Skokomish 268 7,100 9,100 3%
Mid-Hood Canal 33 1,300 5,200 1%
Whidbey Basin Suiattle 627 160 610 103%
NF Stillaguamish 284 4,000 18,000 2%
SF Stillaguamish 32 3,600 15,000 0%
Cascade 290 290 1,200 18%
Upper Sauk 1,302 750 3,030 43%
Lower Sauk 575 1,400 5,600 10%
Skykomish 1,722 8,700 39,000 4%
Snoqualmie 821 5,500 25,000 3%
Upper Skagit 9,502 5,380 26,000 37%
Lower Skagit 2,365 3,900 16,000 15%
Central/South Puget Sound White River** 445      
Green River (Duwamish) 1,548 27,000 27,000 6%
Sammamish 119 1,000 4,000 3%
Cedar 816 2,000 8,200 10%
Nisqually 650 3,400 13,000 5%
Puyallup 527 5,300 18,000 3%

*(5-year geomean/low productivity planning target)*100

**No planning target

 

INTERIM TARGET

Link to interim targets

Table 2. Progress toward the 2020 Recovery Target.
2020 Recovery Target Was it met? Explanation
No declining abundance in any wild Chinook salmon population. Yes Natural-origin spawner abundance increased only very slightly in all populations, and the 25-75th CIs overlapped zero suggesting no change in the populations' abundance.

Improvements in wild Chinook  population abundance in two to four populations in each of the five biogeographic regions.

No Improvements, measured in terms of population abundance increases, were very small and the 25-75th CIs overlapped zero, suggesting no change in any populations' abundance.

 

Salmon recovery in Puget Sound has been guided over the years by collaborative processes. The Puget Sound Salmon Recovery Plan was developed in 2005 by regional experts and adopted by NOAA Fisheries in 2007 to meet obligations under the Endangered Species Act. Subsequently, local experts in each watershed worked together to craft 16 individual chapters of the Recovery Plan to specify local recovery goals, priority recovery actions, and monitoring needs.

In 2017, the Chinook Salmon Implementation Strategy consolidated strategies from the 2005 Puget Sound Salmon Recovery Plan to reflect lessons learned in the last 10 years. The Implementation Strategy and the Puget Sound Salmon Recovery Plan cover the same geographic area, but their targets differ. While the Puget Sound Salmon Recovery Plan largely focuses on specific salmon habitats needed to support Chinook salmon, the Chinook Salmon Implementation Strategy concentrates on the regional support necessary to enable watersheds to implement recovery strategies in their local areas. These recovery planning efforts are now linked with each other and with the Puget Sound Action Agenda so that changes in one will inform changes in the others.

Despite continued investments in restoring salmon habitat in and around streams and rivers, significantly reduced harvest rates, and revisions in hatchery management, the region is not seeing significant progress in increasing Puget Sound Chinook salmon abundance. Chinook salmon utilize a variety of habitats, from freshwater to the ocean, and are therefore vulnerable to stressors associated with change and degradation of habitats across a large area. Furthermore, many of the factors already implicated in the lack of recovery of Chinook salmon are exacerbated by the bio-physical impacts of climate change. From the Northwest Indian Fisheries Commission 2020 State of Our Watersheds Report:

"A consistent trend identified in the 2020 State of Our Watersheds Report is that key habitat features, such as riparian vegetation, habitat connectivity and streamflows, continue to be imperiled by human activities. This extensive loss and degradation of habitat, changing climate and ocean conditions threaten salmon, tribal cultures and tribal treaty-reserved rights, wildlife habitat, water quality and western Washington’s economy and quality of life."

The Salish Sea Marine Survival Project seeks to address the critical question: What are the causes of salmon and stellhead decline in the Salish Sea? Please refer to the Project webpage for more information on the research to assess salmon condition and survival and to view three key hypotheses for what is driving change.

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Subcategories
Name
Time Period
1993-2003, 2013-2017