Sockeye Salmon (Oncorhynchus nerka)
FishSalmonAnadromous
A male and female sockeye salmon spawning in the Adams River, British Columbia, in October 2014.
Image: William Rosmus, CC BY-SA 4.0, via Wikimedia Commons.
Overview
The sockeye salmon (Oncorhynchus nerka) is a Pacific salmon of the North Pacific and its Arctic and Pacific drainages in North America and northeastern Asia. Most sockeye are anadromous — they hatch in fresh water, grow at sea and return to spawn — but a landlocked form, the kokanee, spends its whole life in lakes and streams.
Sea-run adults are metallic green-blue on the back, silver on the sides and white below, with at most fine black speckling and no large spots on the back or tail; long, fine, closely spaced gill rakers help set the species apart. At spawning they turn bright red with a green head, and males grow a humped back and hooked jaws.
Sea-run sockeye measure 1.5 to 2.5 feet and weigh 4 to 15 pounds; adults at sea average 3 kg, and fish ready to spawn weigh 1 to 4 kg. The maximum total length is 84 cm, and the maximum weight is given as 7 or 7.7 kg. Kokanee are smaller, rarely exceeding 1.2 feet.
Habitat & Range
Sockeye use fresh, brackish and salt water at different stages. They hatch in streams, rivers or lakes; the young usually rear in lakes, with estuaries and wetlands also serving as nurseries; and adults live in the open ocean near the surface — the species is recorded to 250 m deep — before returning to fresh water to spawn — in British Columbia and Yukon mostly in lake-fed systems. Kokanee stay in lake-stream systems.
The range runs from Point Hope or Kotzebue Sound, Alaska, south to the Columbia River system — or, in one native-range account, to the Sacramento River drainage in California — and in Asia from the Anadyr River south to the Kuril Islands or Hokkaido. Sea-run sockeye no longer occur naturally in California or Japan, although kokanee populations exist there. Introduced populations are established in New Zealand and Sweden.
Diet
Sockeye feed mainly on zooplankton, with a high share of shrimp and other crustaceans — a diet to which the rich color and oil content of sockeye may be attributed. In fresh water the young also eat amphipods, ostracods, cladocerans and insects; at sea, sockeye add small and larval fishes and occasionally squid, and fish become more important as they grow. Kokanee eat mainly plankton, along with insects and bottom-dwelling animals.
Behavior
Young sockeye generally spend one to three years in a nursery lake (mostly one or two, by another account), and in some populations fry go to sea in their first summer. As smolts they migrate to the ocean and typically stay there two to three years — British Columbia sockeye range west to about the International Date Line — then migrate many miles upstream to spawn, usually in the stream or lake where they hatched. Early returners, called jacks and almost always males, may spend only one winter at sea.
Sockeye travel upstream in runs and form hierarchies at spawning, the largest male usually dominant. A female building nests is attended by a dominant male and a few subordinate males, dominant males may mate with many females, and a female may spawn with several dominant males.
Human Interaction & Conservation
Sockeye are among the most commercially important Pacific salmon, taken in commercial, recreational and Indigenous fisheries; in Canada's Pacific Region they were the first salmon fished commercially and, from the 1870s, the first canned in quantity. In 2024 U.S. commercial landings totaled 196 million pounds, worth about $259 million, almost all from Alaska. Kokanee are stocked for sport fishing, and where introduced, large kokanee populations can compete with trout for zooplankton.
In the United States, the Snake River sockeye population is listed as endangered and the Ozette Lake population as threatened under the US Endangered Species Act. IUCN's global assessment lists the sockeye salmon as Least Concern (2011).
Reproduction & Life Cycle
Sockeye spawn in summer or fall — as late as December in the south of the range — usually in the stream or lake where they hatched. Over 3 to 5 days a female normally digs 3 to 5 nests (redds) in the gravel with her tail and lays 2,000 to 4,500 eggs, which males fertilize and she covers with gravel. The eggs hatch in winter, and the young (alevins) stay in the gravel, living on their yolk sacs, until early spring.
Sockeye mature at two to six years of age, usually four or five, and all adults die within a few weeks of spawning. Sockeye live about 4 to 5 years on average, with a maximum reported age of 8 — neither figure is tied to one form — and kokanee live two to seven years, depending on the stock. In many Fraser River lakes, sockeye are abundant one year in four.
Sourced facts
Each value below is traced to the specific reference that states it. Open a row's evidence to see the source, where to look in it, and how firmly it supports the value. Sources checked 2026-10-20.
| Fact | What the source states | Evidence |
|---|---|---|
| Distinguishing traits | Sea-run adults: metallic green-blue back, silver sides, white belly; at most fine black speckling, with no large or definite spots on the back or tail; gill rakers long, fine and closely spaced. Spawners turn bright red with a green head; males grow a hump and hooked jaws.The gill rakers, relatively few pyloric caeca and fine back speckling set it apart from the other Oncorhynchus species. Spawning males' jaws carry tiny, visible teeth; females are less brilliantly colored, and a few populations turn dull green to yellowish with little red. Landlocked kokanee mature smaller and may lack brilliant colors. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), FishBase (Froese & Pauly, eds.), COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
FishBase (Froese & Pauly, eds.)
COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada
|
| Geographic range | Arctic and Pacific drainages from Point Hope or Kotzebue Sound, Alaska, south to the Columbia River system, or to the Sacramento River drainage, California, in a native-range account; in northeastern Asia from the Anadyr River south to the Kuril Islands or Hokkaido; and the North Pacific.sources disagreeSea-run sockeye no longer occur naturally in California or Japan, although kokanee populations exist there. At sea: northern Japan to the Bering Sea and south to Los Angeles, California. Introduced: established in New Zealand and Sweden and locally in the U.S. (failing elsewhere); also introduced within Canada and to other Japanese lakes; introductions to Argentina, Finland and Denmark did not establish. | Sources disagree · COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada, FishBase (Froese & Pauly, eds.), U.S. Geological Survey, Nonindigenous Aquatic Species Database, National Institute for Environmental Studies, Japan (Invasive Species of Japan), California Academy of Sciences (Eschmeyer's Catalog of Fishes), Integrated Taxonomic Information System (ITIS) — how we knowWhat each reading says
Range limits differ: the North American southern limit is the Columbia River system in two accounts (one describing where the species occurs) but the Sacramento River drainage, California, in a native-range account (a fourth includes California in the natural range); the northern limit is Point Hope or Kotzebue Sound, Alaska; and the Asian southern limit is the southern Kuril Islands or Hokkaido (northern Japan for the North Pacific distribution). COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada
FishBase (Froese & Pauly, eds.)
U.S. Geological Survey, Nonindigenous Aquatic Species Database
National Institute for Environmental Studies, Japan (Invasive Species of Japan)
California Academy of Sciences (Eschmeyer's Catalog of Fishes)
FishBase (Froese & Pauly, eds.)
Integrated Taxonomic Information System (ITIS)
|
| Habitat | Fresh, brackish and marine waters. Hatches in streams, rivers or lakes; young usually rear in lakes, also using estuaries and wetlands as nurseries; adults live in the open ocean (epipelagic; the species is recorded to 250 m deep) before spawning in fresh water. Kokanee stay in lake-stream systems.In British Columbia and Yukon, most sockeye spawn in lake-fed systems: at lake outlets, in lakes, or in streams flowing into lakes. | Matches source · FishBase (Froese & Pauly, eds.), NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada, Fisheries and Oceans Canada (Pacific Region) — how we knowFishBase (Froese & Pauly, eds.)
NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada
Fisheries and Oceans Canada (Pacific Region)
|
| Diet | Mainly zooplankton, with a high share of shrimp and other crustaceans. Young in fresh water also eat amphipods, ostracods, cladocerans and insects, including larvae; at sea, small and larval fishes and occasionally squid. Kokanee: mainly plankton, insects, bottom organisms.Fish become more important in the diet as sockeye grow. The rich color and oil content of sockeye may be attributed to a diet that includes a high percentage of shrimp and other crustaceans. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), FishBase (Froese & Pauly, eds.), Fisheries and Oceans Canada (Pacific Region), U.S. Geological Survey, Nonindigenous Aquatic Species Database — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
FishBase (Froese & Pauly, eds.)
Fisheries and Oceans Canada (Pacific Region)
U.S. Geological Survey, Nonindigenous Aquatic Species Database
|
| Body size | Sea-run adults measure 1.5 to 2.5 feet; maximum total length 84 cm (females up to 71.0 cm). Landlocked kokanee rarely exceed 1.2 feet.One of the smaller Pacific salmon. The foot figures do not name the length measure. Common lengths are given as 45.0 cm total length for males or unsexed fish and 58 cm for females. Spawning size varies with age at maturity, and size at age varies widely among populations. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), FishBase (Froese & Pauly, eds.), COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
FishBase (Froese & Pauly, eds.)
COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada
|
| Body mass | Sea-run sockeye weigh 4 to 15 pounds; adults at sea average 3 kg, and fish ready to spawn weigh 1 to 4 kg. Maximum 7 kg or 7.7 kg (maximum published weight).sources disagree | Sources disagree · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada, FishBase (Froese & Pauly, eds.), Animal Diversity Web (University of Michigan Museum of Zoology) — how we knowWhat each reading says
Maximum mass is up to 7 kg in one account and 7.7 kg (maximum published weight) in another. NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada
COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada
FishBase (Froese & Pauly, eds.)
Animal Diversity Web (University of Michigan Museum of Zoology)
|
| Lifespan | Wild: about 4 to 5 years on average; maximum reported age 8 years. Sockeye mature at around 5 years of age (4 years is more common in the Pacific Northwest) and die within weeks of spawning, though some live longer. Landlocked kokanee: two to seven years, depending on the stock.The 4–5-year average and the 8-year maximum are not tied to either form in their accounts. Age 4 is more common in the Pacific Northwest. No captive lifespan is reported. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Animal Diversity Web (University of Michigan Museum of Zoology), FishBase (Froese & Pauly, eds.) — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Animal Diversity Web (University of Michigan Museum of Zoology)
FishBase (Froese & Pauly, eds.)
|
| Social structure | Social: adults migrate upstream in runs and form hierarchies at spawning, the largest male usually dominant. A nest-digging female is attended by a dominant male and a few subordinate males. Dominant males may mate with many females, and a female may spawn with several dominant males.During nest building, females are aggressive toward other females and subordinate males, and males toward other males; subordinate males may join a spawning pair, and some may not mate at all. | Matches source · Animal Diversity Web (University of Michigan Museum of Zoology), FishBase (Froese & Pauly, eds.) — how we knowAnimal Diversity Web (University of Michigan Museum of Zoology)
FishBase (Froese & Pauly, eds.)
|
| Reproduction | Spawns in summer or fall (to December in the south) in natal streams. Over 3 to 5 days the female normally digs 3 to 5 nests (redds) and lays 2,000 to 4,500 eggs, which males fertilize and she buries in gravel; eggs hatch in winter. All adults die within a few weeks of spawning.Maturity ages of two to six years are recorded, and one age group, usually four-year-olds, dominates most systems; another account gives maturity around age 5, with age 4 more common in the Pacific Northwest. Alevins stay in the gravel on their yolk sacs until early spring. In many Fraser River lakes, sockeye are abundant one year in four. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), FishBase (Froese & Pauly, eds.), Fisheries and Oceans Canada (Pacific Region) — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
FishBase (Froese & Pauly, eds.)
Fisheries and Oceans Canada (Pacific Region)
|
| Movement | Anadromous: young generally spend 1 to 3 years in a nursery lake (mostly one or two in another account), go to sea as smolts, typically stay 2 to 3 years, then migrate many miles upstream to spawn, usually in the stream or lake where they hatched. Kokanee stay in fresh water.sources disagreeIn some populations fry go to sea in their first summer. Early returners ('jacks'), almost always males, may spend only one winter at sea. British Columbia sockeye move north and northwest at sea, ranging west to about the International Date Line (2600 miles from Vancouver Island). Offspring occasionally switch between the sea-run and lake-resident forms. | Sources disagree · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), FishBase (Froese & Pauly, eds.), Fisheries and Oceans Canada (Pacific Region), COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada — how we knowWhat each reading says
Time in the nursery lake differs: generally 1 to 3 years in one account, but mostly one or two (rarely three or four) years in another. NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
FishBase (Froese & Pauly, eds.)
Fisheries and Oceans Canada (Pacific Region)
COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada
|
| Human interaction | Among the most commercially important Pacific salmon, taken in commercial, recreational and Indigenous fisheries; in Canada's Pacific Region the first salmon fished commercially and, from the 1870s, canned in quantity. Kokanee are stocked for sport. Harmless to people.2024 U.S. commercial landings: 196 million pounds (about $259 million), almost all from Alaska. Under the US Endangered Species Act, the Snake River population is listed as endangered (1991) and the Ozette Lake unit as threatened (1999). Large kokanee populations can inhibit trout production by competing for zooplankton; introduced kokanee were at least partly responsible for the loss of three cladoceran species in Lake Tahoe. | Matches source · FishBase (Froese & Pauly, eds.), COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada, Fisheries and Oceans Canada (Pacific Region), NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), U.S. Geological Survey, Nonindigenous Aquatic Species Database, Integrated Taxonomic Information System (ITIS) — how we knowFishBase (Froese & Pauly, eds.)
COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada
Fisheries and Oceans Canada (Pacific Region)
NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
U.S. Geological Survey, Nonindigenous Aquatic Species Database
Integrated Taxonomic Information System (ITIS)
COSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada
|
| Conservation status | Least Concern (LC), global assessment, 2011 | Matches source · IUCN Red List of Threatened Species — how we knowIUCN Red List of Threatened Species
|
References for the facts above
- GovernmentNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)Supports: identification, habitat, diet, body-size, weight, lifespan, reproduction, movement; U.S. fisheries and ESA listings. Retrieved 2026-10-20.Limitations: Species Directory page (last updated 06/29/2026) written for U.S. stocks; its range line ('Northwest Alaska to the Deschutes River in Oregon') covers only the U.S. and was not used; fishery figures are U.S.-only; length measure not named; the clause 'some return earlier or stay at sea longer, between 4 and 5 years' is ambiguous and its 4–5 figure was not used.
- ReferenceFishBase (Froese & Pauly, eds.)Supports: identification, range, habitat, diet, body-size, weight, lifespan, social-structure, reproduction, movement, human-interaction. Retrieved 2026-10-20.Limitations: Compiled summary (page last modified 20 July 2016) citing many references; female common length (58 cm) exceeds the male/unsexed figure (45.0 cm TL) while maximum length is the reverse; its 7.7 kg maximum weight and 8-year maximum age do not say which form they refer to.
- ReferenceFishBase (Froese & Pauly, eds.)Supports: range (introductions outside North America and northeastern Asia). Retrieved 2026-10-20.Limitations: Table of nine introduction records (last modified 03/07/12); establishment is 'unknown' for Chile and Japan; the URL redirects to fishbase.se/introductions/243.
- UniversityAnimal Diversity Web (University of Michigan Museum of Zoology)Supports: weight (spawning adults), lifespan, social-structure. Retrieved 2026-10-20.Limitations: Student-written account (2011, last updated 2011-02-13) headed with the kokanee name 'Kickininee'. Not used: its range (it tags the Palearctic as introduced, although the species was described from Kamchatka), its 'iteroparous' and 'breed once a year' tags (its own text says sockeye die after mating), '47 to as many as 206 offspring' (measure unclear), 'do not defend a territory', and its 15–33 m depth figure.
- ReferenceCalifornia Academy of Sciences (Eschmeyer's Catalog of Fishes)Supports: identity (accepted name, synonyms); range (distribution summary). Retrieved 2026-10-20.Limitations: Taxonomic catalogue (online version updated 21 Sep. 2026); distribution is a one-line summary.
- ReferenceIntegrated Taxonomic Information System (ITIS)Supports: identity (hierarchy, authorship); range (North American native/introduced tags); human-interaction (U.S. ESA listings). Retrieved 2026-10-20.Limitations: Geographic information covers North America only.
- GovernmentCOSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change CanadaSupports: range, habitat, weight, human-interaction. Retrieved 2026-10-20.Limitations: Executive summary of the 2003 status report on the Sakinaw Lake (British Columbia) population (web page 2018-01-04); only species-level statements were used. Not used: its statement that four North American ESUs are 'considered endangered' (the Ozette Lake unit is listed as threatened under the U.S. ESA) and its typical ocean depth (less than 15 m).
- GovernmentCOSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change CanadaSupports: identification, body-size, weight, movement. Retrieved 2026-10-20.Limitations: Species Information chapter of the same 2003 report (web page 2018-01-02); gives 28 to 40 gill rakers where FishBase gives 30 to 40 (counts not used).
- GovernmentU.S. Geological Survey, Nonindigenous Aquatic Species DatabaseSupports: range (native range, U.S. introductions), diet, human-interaction (stocking and impacts). Retrieved 2026-10-20.Limitations: Focused on U.S. introductions (revision date 7/10/2026); its identification paragraph describes kokanee; 'The species is not long-lived (2 years)' sits in a discussion of stocked kokanee and was not used for lifespan; its southern native limit (Sacramento River drainage) differs from other accounts.
- GovernmentFisheries and Oceans Canada (Pacific Region)Supports: habitat, diet, reproduction, movement, human-interaction. Retrieved 2026-10-20.Limitations: Multi-species page on Pacific salmon; only its dedicated sockeye section was used; British Columbia focus.
- GovernmentNational Institute for Environmental Studies, Japan (Invasive Species of Japan)Supports: range (natural range; introductions within Japan and to New Zealand). Retrieved 2026-10-20.Limitations: Short database record (last modified 2011-02-07) compiled partly from FishBase; Japan focus.
- ReferenceIUCN Red List of Threatened SpeciesSupports: The global Red List category and the year of the assessment. Retrieved 2026-10-20.Limitations: Read from the Red List export IUCN publishes to GBIF; iucnredlist.org itself does not answer automated reads. Categories are reassessed over time.
Frequently Asked Questions — Sockeye Salmon
When do sockeye salmon turn red?
As they return to fresh water to spawn: their bodies turn bright red and their heads green, and males develop a humped back and hooked jaws. At sea they are silver with a metallic green-blue back.
Do sockeye salmon die after spawning?
Yes. All sockeye salmon die within a few weeks after spawning, usually at four or five years of age.
What is a kokanee?
A landlocked form of the sockeye salmon that spends its whole life in lake-stream systems. Kokanee mature at a smaller size — rarely over 1.2 feet — and may lack the bright spawning colors of sea-run sockeye.
What do sockeye salmon eat?
Mainly zooplankton, with a high share of shrimp and other crustaceans. Young fish in lakes also eat insects and small crustaceans, and at sea sockeye add small fishes and occasionally squid.
Sources and further reading
Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.
- GovernmentNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration) — Sockeye salmon species page — identification, habitat, diet, body-size, weight, lifespan, reproduction, movement; U.S. fisheries and ESA listings
- ReferenceFishBase (Froese & Pauly, eds.) — Oncorhynchus nerka species summary — identification, range, habitat, diet, body-size, weight, lifespan, social-structure, reproduction, movement, human-interaction
- ReferenceFishBase (Froese & Pauly, eds.) — Oncorhynchus nerka introductions — range (introductions outside North America and northeastern Asia)
- UniversityAnimal Diversity Web (University of Michigan Museum of Zoology) — Oncorhynchus nerka (sockeye salmon) species account — weight (spawning adults), lifespan, social-structure
- ReferenceCalifornia Academy of Sciences (Eschmeyer's Catalog of Fishes) — Oncorhynchus nerka, Eschmeyer's Catalog of Fishes — identity (accepted name, synonyms); range (distribution summary)
- ReferenceIntegrated Taxonomic Information System (ITIS) — Oncorhynchus nerka, TSN 161979 — identity (hierarchy, authorship); range (North American native/introduced tags); human-interaction (U.S. ESA listings)
- GovernmentCOSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada — COSEWIC status report, sockeye salmon: executive summary — range, habitat, weight, human-interaction
- GovernmentCOSEWIC (Committee on the Status of Endangered Wildlife in Canada), via Environment and Climate Change Canada — COSEWIC status report, sockeye salmon: species information — identification, body-size, weight, movement
- GovernmentU.S. Geological Survey, Nonindigenous Aquatic Species Database — Sockeye salmon, Nonindigenous Aquatic Species fact sheet — range (native range, U.S. introductions), diet, human-interaction (stocking and impacts)
- GovernmentFisheries and Oceans Canada (Pacific Region) — Pacific salmon facts: sockeye salmon — habitat, diet, reproduction, movement, human-interaction
- GovernmentNational Institute for Environmental Studies, Japan (Invasive Species of Japan) — Oncorhynchus nerka, Invasive Species of Japan — range (natural range; introductions within Japan and to New Zealand)
- ReferenceIUCN Red List — Oncorhynchus nerka assessment — The global Red List category and the year of the assessment