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What the sources say

Sockeye SalmonOncorhynchus nerka

Every figure, record and mechanism on the Sockeye Salmon profile was written from a source, and this is the working table behind it: 52 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

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Source
01

NOAA Fisheries

Sockeye Salmon. NOAA Fisheries.

The page saysA silver sea-going fish that turns bright red
The source saysSea-going sockeye salmon have iridescent silver flanks, a white belly, and a metallic green-blue top ... their heads turn green and their bodies turn bright redNote: tagline
The page saysand the ocean
The source saysAnadromous sockeye migrate from fresh water habitats to the ocean to further grow, feed, and mature.Note: stats.habitat, ocean half
The page saysSilver at sea, red in the river
The source saysSea-going sockeye salmon have iridescent silver flanks ... their heads turn green and their bodies turn bright redNote: heading
The page saysA sea-going sockeye has iridescent silver flanks, a white belly and a metallic green-blue back
The source saysSea-going sockeye salmon have iridescent silver flanks, a white belly, and a metallic green-blue top
The page sayswhich earns it the nickname "blueback"
The source saysgiving them their "blueback" name
The page saysAs sockeye return to their freshwater spawning grounds, their heads turn green and their bodies turn bright red
The source saysAs sockeye salmon return to their freshwater spawning grounds, their heads turn green and their bodies turn bright red
The page saysSpawning males also grow a humped back and hooked jaws filled with tiny, visible teeth
The source saysSpawning males develop a humped back and hooked jaws filled with tiny, visible teeth.
The page saysA five-year loop
The source saystheir lifespan is about 5 years, although some live longerNote: heading
The page saysSockeye is one of the smaller species of Pacific salmon
The source saysSockeye is one of the smaller species of Pacific salmon
The page saysmeasuring 1.5 to 2.5 feet (about 46 to 76 cm) and weighing 4 to 15 pounds (about 1.8 to 6.8 kg)
The source saysSockeye is one of the smaller species of Pacific salmon, measuring 1.5 to 2.5 feet in length and weighing 4 to 15 pounds.Note: converted: 1.5 ft = 45.7 cm, 2.5 ft = 76.2 cm; 4 lb = 1.8 kg, 15 lb = 6.8 kg
The page saysKokanee, sockeye that spend their whole lives in fresh water
The source saysSome sockeye salmon are not anadromous and spend their entire lives in freshwater. In the Pacific Northwest, non-anadromous sockeye are known as "kokanee."Note: the page scopes it to kokanee, which NOAA names as the non-anadromous sockeye
The page saysrarely exceed 1.2 feet (about 37 cm)
The source saysKokanee (non-anadromous sockeye) rarely exceed 1.2 feet in length.Note: 1.2 ft = 36.6 cm
The page saysA sockeye's lifespan is about 5 years, although some live longer
The source saysThey sexually mature around the age of 5, which means their lifespan is about 5 years, although some live longer.
The page saysMost sockeye hatch in freshwater streams or lakes and generally rear in lakes for 1 to 3 years
The source saysMost sockeye salmon are anadromous—they hatch in freshwater streams and rivers or lakes and generally rear in freshwater lakes for 1 to 3 years
The page saysfeeding mainly on zooplankton (tiny floating animals)
The source saysjuvenile sockeye salmon feed mainly on zooplankton (tiny floating animals)
The page saysThen they migrate to the ocean to feed and grow
The source saysafter which they reach the smolt stage and migrate to the ocean to feed and grow
The page saysThey typically return to fresh water after 2 to 3 years at sea
The source saysThey typically mature and return to fresh water after 2 to 3 years at sea
The page saysThe female digs nests, called redds, with her tail and deposits 2,000 to 4,500 eggs in them
The source saysFemales select spawning sites, dig nests (redds) with their tails, and deposit eggs (between 2,000 and 4,500) in the redds.
The page saysAll sockeye die within a few weeks after spawning
The source saysAll sockeye salmon die within a few weeks after spawning.
The page saysthe carcasses are a valuable source of energy and nutrients to the river ecosystem
The source sayssalmon carcasses are a valuable source of energy and nutrients to the river ecosystem
The page saysIn North America, sockeye range from northwest Alaska to the Deschutes River in Oregon
The source saysRange Northwest Alaska to the Deschutes River in Oregon.Note: NOAA page (last updated 06/29/2026) replaces ADFG's undated Klamath River southern limit
The page saysSharks, lampreys and marine mammals prey on adults at sea, and bears, eagles and occasionally wolves feed on them in fresh water
The source saysSharks, lampreys, and marine mammals prey on adult salmon in the ocean. Bears, eagles, and occasionally wolves feed on sockeye salmon in fresh water.
The page saysThe red shows up on the swim back to fresh water to spawn
The source saysAs sockeye salmon return to their freshwater spawning grounds, their heads turn green and their bodies turn bright red
The page saysIts other common name in Alaska is red salmon
The source saysAs sockeye salmon return to their freshwater spawning grounds, their heads turn green and their bodies turn bright red, hence their other common name in Alaska is “red” salmon.
The page saysA kokanee is a sockeye that spends its entire life in fresh water
The source saysSome sockeye salmon are not anadromous and spend their entire lives in freshwater.Note: the sentence says the fish spend their entire lives in fresh water
The page saysNOAA Fisheries calls these fish non-anadromous
The source saysKokanee (non-anadromous sockeye)
The page saysin the Pacific Northwest they carry the name kokanee
The source saysIn the Pacific Northwest, non-anadromous sockeye are known as "kokanee."
The page saysThey rarely grow past 1.2 feet long
The source saysKokanee (non-anadromous sockeye) rarely exceed 1.2 feet in length.
The page saysNOAA Fisheries reported that as of 2019, one West Coast population was listed as endangered and one as threatened under the US Endangered Species Act
The source saysAs of 2019, one population of sockeye salmon is listed as endangered and one is listed as threatened under the ESA.Note: NOAA page last updated 06/29/2026 still states this; the date stays in the sentence
The page saysA sea-going sockeye is otherwise silver with a blue-green back
The source saysSea-going sockeye salmon have iridescent silver flanks, a white belly, and a metallic green-blue top

Source
02

Alaska Department of Fish and Game

Sockeye Salmon. Alaska Department of Fish and Game.

The page saysswims back to the freshwater system where it hatched
The source saysEventually they return to spawn in the same freshwater system where they were hatched.Note: tagline
The page saysReturns to spawn in the freshwater system where it was hatched
The source saysEventually they return to spawn in the same freshwater system where they were hatched.Note: stats.superpower
The page saysFreshwater lakes, streams and estuaries
The source saysFresh water lakes, streams and estuaries provide important habitat for spawning and rearing sockeye salmon.Note: stats.habitat, freshwater half
The page saysZooplankton, small crustaceans and insects, and occasionally squid and small fish
The source saysfeeding on plankton, insects, small crustaceans, and occasionally squid and small fishNote: stats.diet
The page saysThousands of miles, then home
The source saysAlaska sockeye salmon travel thousands of miles during this time ... Eventually they return to spawn in the same freshwater system where they were hatched.Note: blockquote lead
The page saysAlaska sockeye travel thousands of miles at sea, drifting in the counter-clockwise current of the Alaska Gyre in the Gulf of Alaska
The source saysAlaska sockeye salmon travel thousands of miles during this time, drifting in the counter-clockwise current of the Alaska Gyre in the Gulf of Alaska.
The page saysEventually they return to spawn in the same freshwater system where they were hatched
The source saysEventually they return to spawn in the same freshwater system where they were hatched.
The page saysFrom Oregon to Siberia
The source saysNorth America "– Klamath River, OR to the Chukchi Sea. Asia – Hokkaido, Japan to Anadyr River, SiberiaNote: heading
The page saysIn Asia, they range from Hokkaido, Japan, to the Anadyr River in Siberia
The source saysAsia – Hokkaido, Japan to Anadyr River, Siberia
The page saysThe largest populations are in the rivers that flow into Alaska's Bristol Bay, plus the Fraser River system in Canada
The source saysThe largest sockeye salmon populations are in the Kvichak, Naknek, Ugashik, Egegik, and Nushagak Rivers that flow into Alaska’s Bristol Bay, plus the Fraser River system in Canada.
The page saysIn good years, these runs can number in the tens of millions of fish
The source saysIn good years, these runs can number in the tens of millions of fish.
The page saysSockeye filter zooplankton and other small animals from the water with their gill rakers
The source saysSockeye salmon filter zooplankton and other small animals from the water with their “gill rakers”.
The page saysIn the ocean they also eat small crustaceans, insects, and occasionally squid and small fish
The source saysthey grow quickly during their 1-3 years in the ocean, feeding on plankton, insects, small crustaceans, and occasionally squid and small fish
The page saysAfter thousands of miles at sea, a sockeye returns to spawn in the same freshwater system where it hatched
The source saysEventually they return to spawn in the same freshwater system where they were hatched.Note: vibe.reason; same quote as the body claim "swims back to the freshwater system where it hatched"

Source
03

Rand 2011

Rand (2011). Oncorhynchus nerka. The IUCN Red List of Threatened Species 2011: e.T135301A4071001.

The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC).Note: stats.conservationStatus; category read via GBIF's copy of the Red List
The page saysThe IUCN Red List rates the species Least Concern
The source saysIUCN Red List category: Least Concern (LC).

Source
04

Farrell et al. 2008

Farrell et al. (2008). Pacific Salmon in Hot Water: Applying Aerobic Scope Models and Biotelemetry to Predict the Success of Spawning Migrations. Physiological and Biochemical Zoology.

The page saysTrouble in warm water
The source saysthe success of river migration for the same sockeye population was temperature dependentNote: heading
The page saysfor that same population, the success of the river migration depended on temperature
The source saysrevealed that the success of river migration for the same sockeye population was temperature dependent
The page saysThey tracked individual sockeye up the Fraser River with biotelemetry
The source saysour biotelemetry studies, which tracked the migration of individual sockeye salmon in the Fraser River
The page saysResearchers predicted that unusually high river temperatures in 2004 caused a complete collapse of aerobic scope
The source saysThis close association was then used to predict that the occurrence of a period of anomalously high river temperatures in 2004 led to a complete collapse of aerobic scope during river migration for a portion of one of the sockeye salmon (Oncorhynchus nerka) populations.Note: the population is one of the three Fraser River salmon populations the abstract names The parenthetical defining aerobic scope is a plain-language gloss of the physiological term, not a claim from this source.
The page saysthe data backed the prediction
The source saysThis prediction was corroborated with empirical data from our biotelemetry studies
The page saysThe researchers suggest that the collapse was an important mechanism behind the high salmon mortality seen during the migration
The source sayswe suggest that collapse of aerobic scope was an important mechanism to explain the high salmon mortality observed during their migration

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.