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Cited by 1Fish Ecology and Management StudiesMarine and fisheries researchFish Biology and Ecology Studies

Subyearling Chinook salmon diets in Lower Columbia River estuarine habitats

Open access
Accola, Kerry, Cordell, Jeff, Oxborrow, Bob, Toft, Jason D., Suzumura, Alyssa, Grote, Jeffrey·2025·PLOS One
DOI 10.1371/journal.pone.0325939PMC PMC12161559
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Abstract

The Lower Columbia River and Estuary is critical rearing habitat for juvenile Pacific salmon. Extending from the river mouth to Bonneville Dam 235 river kilometers upstream, the Estuary has been altered by dams, dikes, and habitat loss due to deforestation and wetland removal. Since 2008, five sites have been monitored to identify the long-term status and trends in Lower Columbia River and Estuary juvenile salmon rearing habitat. Here, we address predominantly natural origin juvenile Chinook Oncorhynchus tshawytscha diets and identify spatial and temporal trends in prey consumption, stomach fullness, energy consumption, and the metabolic costs associated with fish size and water temperatures. Juvenile Chinook diets consisted mainly of corophiid amphipods, chironomid dipterans, and cladocerans, with other insects filling in most of the remainder of their diets. Juvenile Chinook salmon diets were stable over time, and stomach fullness and caloric intake was comparable among the sites where most salmon were collected. Juvenile Chinook salmon were frequently in water temperatures above fitness thresholds and higher water temperatures and metabolic rates will require increased foraging as water temperatures rise. Reduced growth, earlier migration, and mismatches between prey production and foraging are near term possibilities. Juvenile salmon rearing resiliency in the estuary can be aided by maintaining sufficient river discharge levels for salmon, and by restoring habitat and habitat connectivity to the mainstem channel.

AI snapshot

Written from the paper’s full text.

TL;DR

Subyearling Chinook salmon diets across five Lower Columbia River and Estuary monitoring sites from 2008–2021 were dominated by corophiid amphipods, chironomid dipterans, and cladocerans, with generally stable diets over time. Stomach fullness and caloric intake were comparable among the main middle-estuary sites, but fish frequently experienced water temperatures above fitness thresholds, implying higher future foraging demands as metabolic costs rise.

Key findings

  • A total of 1,365 juvenile Chinook salmon diets were analyzed from 2008–2021; 18 empty stomachs were removed. Most fish (91%) came from Campbell Slough (n = 343), Welch Island (n = 444), and Whites Island (n = 455), with smaller samples at Franz Lake (n = 83) and Ilwaco Slough (n = 40).
  • Top prey were amphipods, cladocerans, and dipterans. *Americorophium* spp. made up 75% of amphipod counts and weights; *Daphnia* spp. made up 67% of cladoceran counts and weights; chironomids accounted for 47% of dipteran counts and 39% of dipteran weights, and chironomids plus unidentified dipterans comprised 96% of dipterans.
  • Stomach fullness was highest at Ilwaco Slough and lowest at Franz Lake, but comparable among Welch Island, Whites Island, and Campbell Slough. Smaller Chinook (30–65 mm) had higher fullness and caloric intake than larger fish (effect size = 0.39 for both).
  • July had higher energy ration marginal means than other months. Campbell Slough had the highest metabolic costs, and marked hatchery fish had higher metabolic costs, though this was influenced by larger fish in that category. Water temperatures ranged from 4.4–10.9°C in February to 18.9–23.3°C in July.

Methods

  • Diets and temperature data were collected at five Lower Columbia Estuary Partnership Ecosystem Monitoring Program sites: Ilwaco Slough (RKm 6), Welch Island (RKm 53), Whites Island (RKm 72), Campbell Slough (RKm 149), and Franz Lake (RKm 221).
  • Subyearling Chinook were collected since 2008 using boat- or raft-deployed 38 × 3-m variable mesh bag seines; stomachs were preserved in 10% formalin, and prey were counted, blotted dry, weighed to 0.0001 g, and identified to the finest possible taxon.
  • Diet composition was summarized with Index of Relative Importance (IRI), NMDS on Bray-Curtis dissimilarity, ANOSIM, and SIMPER. Stomach fullness (instantaneous ration), energy ration, and maintenance metabolism were modeled with gamma-distributed generalized linear mixed models in R, with site, month, year, fork length bin, mark status, and water temperature as potential variables.

Limitations

  • The paper states that sample sizes were small at Franz Lake and Ilwaco Slough due to sampling challenges and site location, and that rank deficiencies prevented testing interactive effects among sites and months.
  • The paper states that mark status, rather than fork length, was used for maintenance metabolism models because unequal sample sizes among mark/unmarked and length groups would bias interactive effects; several 100+ mm salmon were excluded from analyses.
  • The text makes evident that hatchery and wild fish were pooled for many diet analyses, and the authors call for future bioenergetics modeling and separate hatchery/wild diet analyses to investigate potential diet differences and competition.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1371/journal.pone.0325939

Cites

52 of 52 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

6 of 54 cited sources checked · 2 supported · 0 flagged · accuracy not yet measured

  • Interpretationcitation

    Wetland prey presence in main channel diets highlights the importance of tidal wetlands as prey sources to the varying Chinook life history patterns in the LCRE.

    “Wetland prey presence in main channel diets highlights the importance of tidal wetlands as prey sources to the varying Chinook life history patterns in the LCRE [20]”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [20] GC Roegner, 2012, Distribution, size, and origin of juvenile chinook salmon in shallow-water habitats of the lower Columbia River and estuary, 2002–2007, Marine and Coastal Fisheries source

      The Consequences for Restoration section (page unavailable) says that wetlands and other shallow-water habitats are used by salmon of varied life history types and that preserving those habitats is important. It does not report wetland prey in main-channel diets or establish tidal wetlands as prey sources; the Methods describe sampling fish distribution rather than diets. (LLM, conf=0.82)

      Experimental — accuracy not yet measured
  • Interpretationcitation

    These high energy prey can help mitigate higher metabolic rates due to elevated water temperatures.

    “which can help mitigate higher metabolic rates due to elevated water temperatures [66,67]”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [66] TR Sommer, 2001, Floodplain rearing of juvenile chinook salmon: evidence of enhanced growth and survival, Can J Fish Aquat Sci source
    • cites [67] EA Daly, 2015, Warming Ocean Conditions Relate to Increased Trophic Requirements of Threatened and Endangered Salmon, PLoS One source
  • Interpretationcitation

    Prey tradeoffs indicate an estuary's capacity for salmon diet adaptability.

    “prey tradeoffs indicate an estuary’s capacity for salmon diet adaptability [59,60]”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [59] I Woo, 2019, A Mosaic of Estuarine Habitat Types with Prey Resources from Multiple Environmental Strata Supports a Diversified Foraging Portfolio for Juvenile Chinook Salmon, Estuaries and Coasts source
    • cites [60] P Goertler, 2018, Effects of Extreme Hydrologic Regimes on Juvenile Chinook Salmon Prey Resources and Diet Composition in a Large River Floodplain, Trans Am Fish Soc source

      The Discussion reports that juvenile Chinook Salmon switched prey as availability changed and adaptively responded to flood and drought conditions in the Yolo Bypass. That supports diet adaptability, but the paper does not establish prey tradeoffs as an indicator of an estuary’s overall capacity for it; its findings concern a particular floodplain habitat. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
  • Premisecitation

    Early marine salmon have increased metabolic requirements in warm ocean regimes.

    “early marine salmon have increased metabolic requirements in warm ocean regimes [67]”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [67] EA Daly, 2015, Warming Ocean Conditions Relate to Increased Trophic Requirements of Threatened and Endangered Salmon, PLoS One source
  • Findingreasoning

    Metabolic costs increased month to month.

    “Metabolic costs increased month to month”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Larger, growing fish have higher metabolic requirements.
    • Rests on an assumption: Water temperatures rise as the year progresses.
  • Classified as probably not a substantial claim. 14
  • May combine two claims. 43

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Larger fish can better evade predation, are less susceptible to starvation, and are more efficient foragers.

    “Larger fish can better evade predation, are less susceptible to starvation, and are more efficient foragers [9].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [9] JT Anderson, 1988, A Review of Size Dependant Survival During Pre-recruit Stages of Fishes in Relation to Recruitment, J Northw Atl Fish Sci source

      The Size dependent mortality section reports that larger larvae more often escape predator attacks, supporting the predation part of the claim. The passages on starvation and feeding discuss food availability, growth, and survival, but do not establish that larger fish are less susceptible to starvation or are more efficient foragers. Page numbers are unavailable in our copy. (LLM, conf=0.85)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Chironomids and Americorophium amphipods are also important in main channel yearling salmonid diets, with other insects complementing their diets.

    “Chironomids and Americorophium amphipods are also important in main channel yearling salmonid diets, with other insects complementing their diets [62]”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [62] LA Weitkamp, 2022, Life in the Fast Lane: Feeding and Growth of Juvenile Steelhead and Chinook Salmon in Main‐Stem Habitats of the Columbia River Estuary, Trans Am Fish Soc source

      The Diets section (p. 598) identifies chironomids and corophiid amphipods as major prey of yearling Chinook Salmon and steelhead, and also lists other insects in their diets. Our copy identifies the amphipods only as corophiids, not specifically as Americorophium, so the genus-level attribution is not verified. (LLM, conf=0.87)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingown data

    There were no long-term diet differences among years, except that cladocerans did not become prevalent in juvenile Chinook diets until 2016.

    “There were no long-term diet differences among years, except that cladocerans did not become prevalent in juvenile Chinook diets until 2016.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Stomach contents of sampled juvenile Chinook accurately reflect their recent diet and foraging.

  • May combine two claims.

    Findingown data

    Smaller Chinook had higher fullness marginal mean values than larger fish, so accounting for their body weight, they were filling their stomachs more than larger fish (effect size = 0.39).

    “Smaller Chinook had higher fullness marginal mean values than larger fish, so accounting for their body weight, they were filling their stomachs more than larger fish (effect size = 0.39; Table 2).”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Stomach contents of sampled juvenile Chinook accurately reflect their recent diet and foraging.

  • May combine two claims.

    Findingown data

    Adult/emergent chironomids were the most numerous chironomid life stage (44%), and pupa made up the most weight (60%) in the diets.

    “Adult/emergent chironomids were the most numerous chironomid life stage (44%), and pupa made up the most weight (60%) in the diets.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Stomach contents of sampled juvenile Chinook accurately reflect their recent diet and foraging.

  • May combine two claims.

    Findingown data

    Fish fullness, measured by instantaneous ration, was highest at Ilwaco Slough and lowest at Franz Lake.

    “Fish fullness, measured by instantaneous ration, was highest at Ilwaco Slough and lowest at Franz Lake”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Stomach contents of sampled juvenile Chinook accurately reflect their recent diet and foraging.

  • May combine two claims.

    Findingreasoning

    Most smaller study Chinook were wild fry, most hatchery Chinook were larger fingerlings due to release protocols, yet larger fish were a comparable mixture of wild and hatchery origin.

    “In general, most smaller study Chinook were wild fry, most hatchery Chinook were larger fingerlings due to release protocols, yet larger fish were a comparable mixture of wild and hatchery origin.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Presence or absence of an adipose fin accurately distinguishes marked hatchery juvenile Chinook from wild or unmarked fish.

  • May combine two claims.

    Findingown data

    Americorophium spp. (mostly A. salmonis, then A. spinicorne) comprised 75% of the amphipod counts and weights and were predominant in Welch and Whites Islands' salmon diets.

    “Americorophium spp. (mostly A. salmonis, then A. spinicorne) comprised 75% of the amphipod counts and weights and were predominant in Welch and Whites Islands’ salmon diets.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Stomach contents of sampled juvenile Chinook accurately reflect their recent diet and foraging.

  • May combine two claims.

    Findingown data

    Stomach fullness was comparable among Welch Island, Whites Island, and Campbell Slough, and there was no statistical difference in fish fullness among months.

    “Stomach fullness was comparable among Welch Island, Whites Island, and Campbell Slough, and there was no statistical difference in fish fullness among months.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Stomach contents of sampled juvenile Chinook accurately reflect their recent diet and foraging.

  • May combine two claims.

    Findingown data

    Within dipterans, chironomids accounted for 47% of the counts and 39% of the weights.

    “Within dipterans, chironomids accounted for 47% of the counts and 39% of the weights.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Stomach contents of sampled juvenile Chinook accurately reflect their recent diet and foraging.

  • May combine two claims.

    Findingcitation

    Juvenile Chinook primarily consumed chironomids and other dipterans and insects at Franz Lake, included cladocerans at Welch Island, Whites Island, and Campbell Slough (predominantly at Campbell Slough), and consumed a mixture of mostly corophiid amphipods and chironomid dipterans at Whites Island, Welch Island, and Ilwaco Slough.

    “Juvenile Chinook primarily consumed chironomids and other dipterans and insects at the most upstream site (Franz Lake), included cladocerans at Welch Island, Whites Island, and Campbell Slough (although predominantly at Campbell Slough), and consumed a mixture of mostly corophiid amphipods and chironomid dipterans at Whites Island, Welch Island, and Ilwaco Slough”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [35] SA Kidd, 2022

      Not checked in the free run.

    • cites [31] GT McCabe, 1986, Utilization of the Columbia River estuary by subyearling chinook salmon, Northwest Science
    • Rests on an assumption: Stomach contents of sampled juvenile Chinook accurately reflect their recent diet and foraging.

  • May combine two claims.

    Findingown data

    Fish netted at Whites Island, Welch Island, and Ilwaco Slough had more similar diets, and Campbell Slough and Franz Lake diets had dipterans in common but differed based on the presence or absence of cladocerans.

    “Fish netted at Whites Island, Welch Island, and Ilwaco Slough had more similar diets, and Campbell Slough and Franz Lake diets had dipterans in common, but differed based on the presence or absence of cladocerans.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Stomach contents of sampled juvenile Chinook accurately reflect their recent diet and foraging.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    In June, water temperature averages ranged from 14.9-20.8 oC.

    “In June, the water temperature average ranged from 14.9ºC – 20.8ºC.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Water temperature measurements at sampling times reflect thermal exposure relevant to juvenile Chinook metabolic costs.

  • May combine two claims.

    Findingown data

    Most high water temperatures occurred at Welch Island, Whites Island, and Campbell Slough, where the majority of juvenile Chinook were sampled.

    “Most high temperatures occurred at Welch Island, Whites Island, and Campbell Slough, where the majority of juvenile Chinook were sampled”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Water temperature measurements at sampling times reflect thermal exposure relevant to juvenile Chinook metabolic costs.

  • May combine two claims.

    Findingown data

    Most Chinook salmon (91%) used for diet analyses were netted at Campbell Slough, Welch Island, and Whites Island, with small sample sizes at Franz Lake and Ilwaco Slough.

    “Most Chinook salmon (91%) used for diet analyses were netted at the middle three EMP sites (Campbell Slough (n = 343), Welch Island (n = 444), and Whites Island (n = 455), with small overall sample sizes at Franz Lake (n = 83) and Ilwaco Slough (n = 40).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Juvenile Chinook counts were highest in May (n = 593), and most salmon were in the smallest length category (30-65 mm fork length; n = 775).

    “Juvenile Chinook counts were highest in May (n = 593), and most salmon were in the smallest length category (30–65 mm fork length; n = 775)”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    Stomach fullness results from our study differ from [31], who found upstream diets had the fullest stomachs, while downstream stomachs were emptier.

    “Stomach fullness results from our study differ from [31], who found upstream diets had the fullest stomachs, while downstream stomachs were emptier.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] GT McCabe, 1986, Utilization of the Columbia River estuary by subyearling chinook salmon, Northwest Science

  • May combine two claims.

    Findingown data

    The status and trends of juvenile Chinook diets at five monitoring sites in the LCRE show stable diets, dominated by amphipods and dipterans, and cladocerans.

    “the status and trends of juvenile Chinook diets at five monitoring sites in the Lower Columbia River and Estuary shows stable diets, dominated by amphipods and dipterans, and cladocerans”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Salmon densities decline in June, but May has continued to be the peak month of juvenile Chinook abundances sampled throughout our study period.

    “Salmon densities decline in June, but May has continued to be the peak month of juvenile Chinook abundances sampled throughout our study period.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    All size classes of sampled Chinook had similar interannual prey trends, in which three taxa (corophiid amphipods, cladocerans, and chironomid dipterans) comprised most of the diets.

    “All size classes of sampled Chinook had similar interannual prey trends, in which three taxa (corophiid amphipods, cladocerans, and chironomid dipterans) comprised most of the diets.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Diets of pooled hatchery and wild fish with different lengths did not differ in our study, and diet contents through time were stable.

    “Diets of pooled hatchery and wild fish with different lengths did not differ in our study, and diet contents through time were stable.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Most Campbell Slough salmon were larger fish, in large part due to hatchery fish prevalence.

    “Most Campbell Slough salmon were larger fish, in large part due to hatchery fish prevalence”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    Salmon counts peaked in May each year, then decreased throughout summer.

    “Salmon counts peaked in May each year, then decreased throughout summer”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    Although caloric intake was highest in July, stomach fullness was not.

    “Although caloric intake was highest in July, stomach fullness was not.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    Smaller fish were predominantly wild and larger fish had higher percentages of hatchery fish.

    “though smaller fish were predominantly wild and larger fish had higher percentages of hatchery fish”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    Beginning in 2016, cladocerans became more prominent in salmon diets at Campbell Slough, with amphipods and dipterans remaining important prey throughout the study period.

    “Beginning in 2016, cladocerans became more prominent in salmon diets at Campbell Slough, with amphipods and dipterans remaining important prey throughout the study period.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Although few juvenile Chinook were netted at Ilwaco Slough, juvenile chum counts were highest at this site and Chinook were present in low densities in spring months.

    “Although few juvenile Chinook were netted at Ilwaco Slough, juvenile chum counts were highest at this site and Chinook were present in low densities in spring months.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    Prey included high energy dipterans, hemipterans, hymenopterans, trichopterans (all insects), and amphipods.

    “Prey included high energy dipterans, hemipterans, hymenopterans, trichopterans (all insects), and amphipods”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Tidal wetlands are a primary source of salmon prey in the wetlands and in the estuary, as salmon disproportionately favor these allochthonous prey sources.

    “Tidal wetlands are a primary source of salmon prey in the wetlands and in the estuary, as salmon disproportionately favor these allochthonous prey sources [30].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [30] Bottom D, Jones K, Herring M. Fishes of the Columbia River estuary. Final Report on the Fish Work Unit of the Columbia River Estuary Data Development Program. 1984 Jan 1.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Premisecitation

    Growth during the first year of life is linked to marine survival and spawning in salmon.

    “Growth during their first year of life is linked to marine survival and spawning [5,6]”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [5] Reimers PE. The length of residence of juvenile fall Chinook salmon in Sixes River, Oregon. 1971;111.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [6] A Magnusson, 2003, Estuarine influence on survival rates of coho (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha) released from hatcheries on the U.S. Pacific coast, Estuaries source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Water temperatures regularly exceed salmon fitness standards at Campbell Slough.

    “water temperatures regularly exceed salmon fitness standards [35].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [35] SA Kidd, 2022

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Anthropogenic changes beginning in the 1860s including agriculture, dike building, and dam construction altered water quality and habitat conditions, resulting in loss of 68-70% of vegetated tidal wetlands.

    “anthropogenic changes beginning in the 1860s including agriculture, dike building, and dam construction for the hydropower system, altered water quality and habitat conditions [23–25], resulting in loss of 68–70% of vegetated tidal wetlands [26].”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [23] Rao S, Kidd SA, Fuller RN, McNatt R, Poppe K, Peterson TD, et al. Lower Columbia River Ecosystem Monitoring Program Annual Report for Year 15 (October 1, 2018 to September 30, 2019). Prepared by the Lower Columbia Estuary Partnership for the Bonneville Power Administration. Available from the Lower Columbia Estuary Partnership, Portland, OR. 2019.

      Not checked in the free run.

    • cites [24] JM Myers, 2006

      Not checked in the free run.

    • cites [25] CA Simenstad, 1990, Columbia river estuary studies: An introduction to the estuary, a brief history, and prior studies, Progress in Oceanography source
    • cites [26] K Marcoe, 2017, Habitat change in the lower Columbia River estuary, 1870–2009, Journal of Coastal Conservation source

  • May combine two claims.

    Interpretationcitation

    Higher July caloric intake was likely due to highly nutritious prey including Trichoptera, Hemiptera, and Hymenoptera replacing some amphipods in the Welch and Whites Island's diets, and fish and insects replacing cladocerans in Campbell Slough diets.

    “Higher July caloric intake was likely due to highly nutritious prey including Trichoptera, Hemiptera, and Hymenoptera replacing some amphipods in the Welch and Whites Island’s diets, and fish and insects replacing cladocerans in Campbell Slough diets”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [55] CA Haskell, 2017, Trophic Interactions and Consumption Rates of Subyearling Chinook Salmon and Nonnative Juvenile American Shad in Columbia River Reservoirs, Trans Am Fish Soc source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The LCRE, extending from the river mouth to Bonneville Dam (235 river kilometers), was designated an "Estuary of National Significance" in 1995.

    “In 1995, the LCRE, extending from the river mouth to Bonneville Dam (235 river kilometers (RKm)), was designated an “Estuary of National Significance” [23].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [23] Rao S, Kidd SA, Fuller RN, McNatt R, Poppe K, Peterson TD, et al. Lower Columbia River Ecosystem Monitoring Program Annual Report for Year 15 (October 1, 2018 to September 30, 2019). Prepared by the Lower Columbia Estuary Partnership for the Bonneville Power Administration. Available from the Lower Columbia Estuary Partnership, Portland, OR. 2019.

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The Washington Department of Ecology recommends a threshold of 17.5oC as a water temperature standard.

    “The Washington Department of Ecology recommends a threshold of 17.5ºC as a water temperature standard [44].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [44] Washington State Water Quality Standards. WAC 173-201A-200. Fresh water designated uses and criteria. 2023.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationreasoning

    Their downstream subyearling Chinook were offshore and migrating rapidly, while our Ilwaco Slough subyearling fish were smaller and likely utilizing off-channel habitats to increase growth before leaving the estuary.

    “Their downstream subyearling Chinook were offshore and migrating rapidly, while our Ilwaco Slough subyearling fish were smaller and likely utilizing off-channel habitats to increase growth before leaving the estuary.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Compared to warmer streams, Chinook grew faster with maximum temperatures of 16oC.

    “[68] found that compared to warmer streams, Chinook grew faster with maximum temperatures of 16ºC.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [68] PA Bisson, 1976, Production of juvenile chinook salmon, Oncorhynchus tshawytscha, in a heated model stream, Fishery Bulletin

  • May combine two claims.

    Interpretationreasoning

    The decrease in small fish counts was because some small fish transitioned to a larger size class, while others left the estuary or died.

    “because some small fish transitioned to a larger size class, while others left the estuary or died”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    First year growth includes early ocean entry, so estuarine growth may be able to be postponed in system-specific situations.

    “First year growth includes early ocean entry, so estuarine growth may be able to be postponed in system-specific situations [71]”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [71] RB MacFarlane, 2010, Energy dynamics and growth of Chinook salmon (Oncorhynchus tshawytscha) from the Central Valley of California during the estuarine phase and first ocean year, Can J Fish Aquat Sci source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    At Campbell Slough, reduced connectivity to the main channel in low water periods may have increased water temperatures, but also facilitated retaining wetland insects more than open sites like Welch and Whites Islands.

    “This was especially true at Campbell Slough, where reduced connectivity to the main channel in low water periods may have increased water temperatures, but also facilitated retaining wetland insects more than open sites like Welch and Whites Islands.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisenone given

    The three lower estuary sites (Ilwaco Slough, Welch Island, Whites Island) are tidally driven and inundated several hours each day, while Franz Lake and Campbell Slough are off channel sites with reduced connectivity to the mainstem and are therefore more affected by freshet and dam discharge.

    “The three lower estuary sites (Ilwaco Slough, Welch Island, Whites Island) are tidally driven and inundated several hours each day, while Franz Lake and Campbell Slough are off channel sites with reduced connectivity to the mainstem and are therefore more affected by freshet and dam discharge.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Agriculture, residential development, and dams have modified critical juvenile salmon rearing habitat in the LCRE.

    “Agriculture, residential development, and dams have modified critical juvenile salmon rearing habitat in the LCRE [23].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [23] Rao S, Kidd SA, Fuller RN, McNatt R, Poppe K, Peterson TD, et al. Lower Columbia River Ecosystem Monitoring Program Annual Report for Year 15 (October 1, 2018 to September 30, 2019). Prepared by the Lower Columbia Estuary Partnership for the Bonneville Power Administration. Available from the Lower Columbia Estuary Partnership, Portland, OR. 2019.

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Main channel complexity is important for growth, as vegetated shoreline habitats can provide insects for salmon and channel complexity can reduce flushing of salmon in high flow periods.

    “Main channel complexity is also important for growth, as vegetated shoreline habitats can provide insects for salmon and channel complexity can reduce flushing of salmon in high flow periods [70].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [70] CA Jeffres, 2008, Ephemeral floodplain habitats provide best growth conditions for juvenile Chinook salmon in a California river, Environmental Biology of Fishes source

  • May combine two claims.

    Interpretationcitation

    Challenges of sampling access at Franz Lake and the location of Ilwaco Slough near the mouth of the estuary likely contributed to low Chinook densities at these sites.

    “Challenges of sampling access at Franz Lake, which was hindered by beaver dams and water levels [35], and the location of Ilwaco Slough near the mouth of the estuary, where salmon may quickly pass through to the ocean, likely contributed to low Chinook densities at these sites.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [35] SA Kidd, 2022

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Juvenile Chinook use emergent marsh habitat for multiple weeks, growing 0.53 mm/day, re-entering the same habitats after vacating them during ebb tides.

    “[21] found juvenile Chinook use emergent marsh habitat for multiple weeks, growing 0.53 mm/day, re-entering the same habitats after vacating them during ebb tides.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [21] RA McNatt, 2016, Residency and Movement of Juvenile Chinook Salmon at Multiple Spatial Scales in a Tidal Marsh of the Columbia River Estuary, Trans Am Fish Soc source

  • May combine two claims.

    Premisecitation

    Natural estuarine habitats offer refuge from predation and prey production for growth.

    “because natural estuarine habits offer refuge from predation [6] and prey production for growth [15]”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [6] A Magnusson, 2003, Estuarine influence on survival rates of coho (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha) released from hatcheries on the U.S. Pacific coast, Estuaries source
    • cites [15] Bottom D, Simenstad C, Baptista A, Jay D, Burke J, Jones K. Salmon at River’s End: The Role of the Estuary in the Decline and Recovery of Columbia River Salmon. 2005.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    The accessibility of cladocerans likely contributed to their high biomass in diets, enabling higher salmon growth rates in Campbell Slough and similar habitats.

    “Their accessibility likely contributed to their high biomass in diets, enabling higher salmon growth rates in Campbell Slough and similar habitats”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Cladocerans are slow-moving prey that are easily captured but are less nutritious than other top prey.

  • May combine two claims.

    Premisecitation

    Franz Lake and Campbell Slough have higher fish diversity and richness, driven by introduced species that are tolerant of warm temperatures and low dissolved oxygen.

    “Franz Lake and Campbell Slough have higher fish diversity and richness, driven by introduced species that are tolerant of warm temperatures and low dissolved oxygen [21].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [21] RA McNatt, 2016, Residency and Movement of Juvenile Chinook Salmon at Multiple Spatial Scales in a Tidal Marsh of the Columbia River Estuary, Trans Am Fish Soc source

  • May combine two claims.

    Interpretationreasoning

    While juvenile Chinook migration currently peaks in May, increasing annual water temperatures will lead to higher energy requirements to maintain growth to compensate for increased metabolic costs, or to fish emigrating at smaller sizes than is optimal for first year survival.

    “While juvenile Chinook migration currently peaks in May, increasing annual water temperatures will lead to higher energy requirements to maintain growth to compensate for increased metabolic costs, or to fish emigrating at smaller sizes than is optimal for first year survival.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Larger, growing fish have higher metabolic requirements.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Lower water temperatures also benefit Chinook over their non-salmonid competitors.

    “Lower water temperatures also benefit Chinook over their non-salmonid competitors [69].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [69] Hillman TW. The effect of temperature on the spatial interaction of juvenile chinook salmon and the redside shiner and their morphological differences. Doctorate dissertation. Idaho State University; 1991.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationcitation

    Re-entry indicates foraging-related movement patterns, as salmon use secondary channels against outgoing tides during peak emergence times of prey insects.

    “Re-entry indicates foraging-related movement patterns, as salmon use secondary channels against outgoing tides during peak emergence times of prey insects [21].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [21] RA McNatt, 2016, Residency and Movement of Juvenile Chinook Salmon at Multiple Spatial Scales in a Tidal Marsh of the Columbia River Estuary, Trans Am Fish Soc source
51 of 51

  • The paper relies on this without support.

    Stomach contents of sampled juvenile Chinook accurately reflect their recent diet and foraging.

    “In the laboratory, entire stomachs were analyzed, and each prey taxon was counted, blotted dry, weighed to the nearest 0.0001 g, and identified to the finest possible taxonomic unit”

  • The paper relies on this without support.

    Presence or absence of an adipose fin accurately distinguishes marked hatchery juvenile Chinook from wild or unmarked fish.

    “mark status to distinguish marked hatchery fish from wild or unmarked fish (marked or unmarked; indicated by presence/absence of an adipose fin) the best estimate of fish origin”

  • The paper relies on this without support.

    The five EMP sites represent juvenile Chinook rearing habitats in the Lower Columbia River and Estuary.

    “The sites are currently located at Ilwaco Slough (RKm 6), Welch Island (RKm 53), Whites Island (RKm 72), Campbell Slough (RKm 149), and Franz Lake (RKm 221)”

  • The paper relies on this without support.

    Water temperature measurements at sampling times reflect thermal exposure relevant to juvenile Chinook metabolic costs.

    “water temperature at time of fish sampling”

  • The paper relies on this without support.

    Larger, growing fish have higher metabolic requirements.

    “because larger, growing fish have higher metabolic requirements”

  • The paper relies on this without support.

    Water temperatures rise as the year progresses.

    “water temperatures, which increase gastric evacuation rates [56], rise as the year progresses”

  • The paper relies on this without support.

    Cladocerans are slow-moving prey that are easily captured but are less nutritious than other top prey.

    “Cladocerans are slow-moving prey that are easily captured but are less nutritious than other top prey”

  • The paper relies on this without support.

    Corixids tend to have tougher exoskeletons and be less easily digestible than other hemipterans.

    “which tend to have tougher exoskeletons and be less easily digestible than other hemipterans”

  • The paper relies on this without support.

    Chironomid dipterans are linked to both aquatic and terrestrial habitats as they progress from larvae to adults.

    “chironomid dipterans, are linked to both aquatic and terrestrial habitats as they progress from larvae to adults”

  • The paper relies on this without support.

    The LCRE lacks protective marine embayments outside the estuary.

    “the LCRE lacks protective marine embayments outside the estuary”
10 of 10

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Energy-ration equation omits the stated prey-mass multiplication

    Minor

    The prose defines energy ration by multiplying each prey mass by its energy density before summing. The displayed equation instead divides a sum of prey energy densities by fish weight, omitting prey mass.

  • Monthly caloric-intake effect sizes have the wrong sign

    Minor

    Table 2 gives positive caloric-intake effect sizes of 0.022 and 0.011 for May-July and June-July, although their respective marginal-mean differences are −0.69 and −0.76. Under the table's definition of Cohen's d, dividing those differences by a positive standard deviation cannot reverse their signs.

2 of 2

Cites

Flagged first, then by citations

Research works printed but not linked: 12

  1. WH Rich, 1929, Experiments in marking young chinook salmon on the Columbia River, 1916 to 1927. (1929), pp. 215- S 264, 85 figs
  2. WH Rich, 1920, Early life history and seaward migration of Chinook salmon in the Columbia and Sacramento Rivers, US Bur Fish Bull, 37, 74
  3. National Marine Fisheries Service (NMFS), 2011, Columbia River Estuary ESA Recovery Plan Module for Salmon and Steelhead. NMFS Northwest Region
  4. MA Lott, 2004, Habitat-specific feeding ecology of ocean-type Chinook salmon in the lower Columbia River estuary. M.Sc. Thesis, 124
  5. SA Kidd, 2022, Lower Columbia River Ecosystem Monitoring Program Annual Report for Year 16 (October 1, 2020 to September 30, 2021). Prepared by the Lower Columbia Estuary Partnership for the Bonneville Power Administration
  6. R Merritt, 2008, An Introduction to The Aquatic Insects of North America: Fourth Edition, The Journal of Animal Ecology
  7. J Sagar, 2013, Juvenile salmon ecology in tidal freshwater wetlands of the lower Columbia River and estuary: synthesis of the ecosystem monitoring program, 2005-2010
  8. SA Kidd, 2019, Lower Columbia River Ecosystem Monitoring Program Annual Report for Year 14 (October 1, 2017 to September 30, 2018). Prepared by the Lower Columbia Estuary Partnership for the Bonneville Power Administration
  9. Posit team, 2024, Studio: Integrated Development Environment for R
  10. D Thomas, 1983, Changes in Columbia River Estuary habitat types over the past century. Columbia River Estuary Data Development Program
  11. PNNL (Pacific Northwest National Laboratory) and NMFS (National Marine Fisheries Service), 2020, Restoration action effectiveness monitoring and research in the lower Columbia River and estuary, 2016–2017
  12. Hillman TW. The effect of temperature on the spatial interaction of juvenile chinook salmon and the redside shiner and their morphological differences. Doctorate dissertation. Idaho State University; 1991.

Cited by

Still being checked.

Related

Authors
Accola, K., Cordell, J., Oxborrow, B., Toft, J. D., Suzumura, A., & Grote, J.
Affiliations
University of Washington (US)
Corresponding author
Accola, Kerry
ORCID
Venue
PLOS One
Publisher
Public Library of Science (PLoS)
Published
2025-06-12
Volume
20
Issue
6
Pages
e0325939
ISSN
1932-6203 (ISSN-L)
DOI
10.1371/journal.pone.0325939
PMC
PMC12161559
OpenAlex
W4411234312
Semantic Scholar
280fe7713dd21137390e02236872d35f9747cf85
Cited by
1
References
52
Citations by year
2026: 1
FWCI
0.65
Type
journal article
Language
en
Open access
Licence
Locations
  • PLoS ONE (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
Bonneville Power Administration (11-2024)
Topics
  • Physical Sciences › Environmental Science › Nature and Landscape Conservation › Fish Ecology and Management Studies
  • Physical Sciences › Environmental Science › Global and Planetary Change › Marine and fisheries research
  • Life Sciences › Agricultural and Biological Sciences › Aquatic Science › Fish Biology and Ecology Studies
Keywords
Oncorhynchus tshawytscha, prey consumption, stomach fullness, energy consumption, metabolic rate, water temperature, Chironomidae, Cladocera, habitat connectivity, river discharge, habitat restoration, foraging, migration timing
MeSH terms
Animals, Diet, Salmon, Temperature, Ecosystem, Rivers, Estuaries

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-27.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-27.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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