Atlantic Mackerel (Scomber scombrus)
FishSchoolingNorth Atlantic
Overview
The Atlantic mackerel (Scomber scombrus) is a fast, streamlined fish of cold and temperate waters on both sides of the North Atlantic. It lives in schools near the surface over the continental shelf and is known for vast annual migrations between feeding and spawning grounds.
Its slender body has a long, pointed snout and a strongly forked tail. The back is iridescent blue-green to steel blue, crossed by 20 to 30 black bars — described as wavy, or as oblique to near vertical with relatively little undulation — that run over the upper half of the body and end at mid-flank, with a narrow dark streak below them; the belly is silvery and unmarked. It has no swim bladder and must keep swimming to breathe, and its colors fade quickly after death.
Maximum length is given as about 45 cm or 16 ½ inches in North American accounts, and as 60.0 cm fork length, over 60 cm or 65 cm in global and European ones. Maximum weight differs in the same way — 800 grams or 2.2 pounds in North American accounts, 3.4 or 3.5 kg in others — and a Norwegian account says mackerel usually weigh less than 1 kg. Young grow fast: they can reach 20 cm by November of their first year in a Canadian account, and 22 cm after one year and 30 cm after two years in a Northeast Atlantic account.
Habitat & Range
Atlantic mackerel live in the open water of cold and temperate seas over the continental shelf, near the surface, in salt and brackish water. They are recorded from the surface to 1,000 m but usually stay above 200 m, and they prefer a narrow temperature range of 7 to 16°C. Around Britain and Ireland they are more abundant on the shelf edges in winter.
In the western Atlantic they live in coastal waters from Labrador to North Carolina. In the east they range from Morocco and the Iberian Peninsula north to the northern Norwegian Sea and Svalbard and west to Iceland and Greenland, and they occur in the North, Baltic, Mediterranean and Black seas and the Sea of Marmara. Northeast and Northwest Atlantic mackerel are genetically distinct, and no migration across the Atlantic is known. In the mid-2000s the summer feeding range of Northeast Atlantic mackerel in the Nordic Seas began expanding into new areas far to the north and west.
Diet
Atlantic mackerel eat zooplankton — especially crustaceans such as copepods, krill and shrimp — as well as fish larvae, small fish, squid and some ascidians, sac-like filter-feeding invertebrates. In Northeast Atlantic accounts, named fish prey include capelin, sandeel, herring, sprat and Norway pout; crustaceans make up almost half of the food by weight and juvenile fish the rest; feeding varies with season, area and the size of the fish and nearly stops in winter; and herring are the main competitors for prey. Mackerel there seem very opportunistic in where they feed, exploiting any available ocean area from one year to the next.
Behavior
Mackerel form large schools near the surface, primarily as a defense against predators; shoals up to 9 km long, 4 km wide and 40 m deep have been reported. After spawning, adults feed very actively while moving around in small shoals.
Their annual migrations are vast. In the northeast, much of the stock winters in deeper water near the shelf edge of the northern North Sea; part of it gathers in February and March before heading south to spawn, and the principal feeding migration then runs north and west into the Nordic Seas — in years when the stock was large, as far as Greenland waters and the Svalbard area. In the northwest, the northern group feeds in Canadian waters from the end of July to October or November after spawning, then moves south into deeper water for the winter. Mackerel move closer to shore in spring, when the water is 11 to 14°C.
Human Interaction & Conservation
The Atlantic mackerel supports one of the biggest fisheries in the North Atlantic, with recent international catches of about 1 million tonnes and a first-sale value of over 10 billion NOK. It is also a gamefish, and in eastern Canada it supports commercial, bait, recreational and Indigenous fisheries; a significant quantity of the Canadian commercial catch is used as bait in other fisheries. It is harmless to people.
In the Northeast Atlantic the mackerel is managed and fished as one stock. Unilateral quotas have added up to catches averaging 39% above the scientific advice since 2010, and in 2025 the stock was estimated to be below both MSY Btrigger and Blim. The North Sea stock fell dramatically in the 1960s through direct overfishing, and Canadian landings have been below 12,000 t since 2011. IUCN's global assessment lists the Atlantic mackerel as Least Concern (2023).
Reproduction & Life Cycle
Atlantic mackerel are batch spawners, and their eggs float near the surface. In the Northwest Atlantic, a southern group spawns in April and May — primarily in the Mid-Atlantic Bight by one account, or off southern New England and in the western Gulf of Maine by another — and a northern group in June and July, mainly in the southern Gulf of St. Lawrence; both typically spawn 10 to 30 miles offshore. In the Northeast Atlantic, spawning runs from March to July, mainly south and west of the UK and Ireland: it begins in the Celtic Sea, Bay of Biscay and Cantabrian Sea and moves north to the Faroe Islands and the Norwegian coast by June. North Sea mackerel spawn from May to July, or later, around June and July, by another account.
Accounts differ on egg numbers: a U.S. account gives 285,000 to almost 2 million eggs per female, depending on size, released in five to seven batches a season, while a Scottish account of Northeast Atlantic fish gives about twenty batches and around 250,000 eggs for an average-sized fish. The eggs hatch in 4 to 7 ½ days or in 1 to 6 days, by different accounts, depending on water temperature. Mackerel typically mature by 2 or 3 years.
Maximum age is given as 17, 20 or 25 years, depending on the account, and a Norwegian account says mackerel usually live no longer than 10–15 years.
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 | Slender, streamlined body with a long, pointed snout and a strongly forked tail. Back iridescent blue-green to metallic or steel blue, with 20 to 30 wavy black bars across the upper half and a narrow dark streak below them; belly unmarked and silvery. No swim bladder.Described as a small, fast fish. The bars are described as wavy in two accounts and as oblique to near vertical, with relatively little undulation, in two others; they end mid-flank, and the flanks are lighter silver. It must keep swimming to breathe. The anal fin begins opposite the second dorsal fin. The distinctive coloring fades quickly after death. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Fisheries and Oceans Canada, Institute of Marine Research (Havforskningsinstituttet), Norway, FishBase (Froese & Pauly, eds.), Marine Life Information Network (MarLIN), Marine Biological Association of the UK — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Fisheries and Oceans Canada
Institute of Marine Research (Havforskningsinstituttet), Norway
FishBase (Froese & Pauly, eds.)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
|
| Geographic range | Found on both sides of the North Atlantic: Labrador to North Carolina in the west; in the east from Morocco and the Iberian Peninsula north to the northern Norwegian Sea and Svalbard, west to Iceland and Greenland, and in the North, Baltic, Mediterranean and Black seas.In the west it lives in coastal waters. Also recorded in the Sea of Marmara and the Arctic Ocean, including the White Sea. Northeast and Northwest Atlantic fish are genetically distinct. In the mid-2000s, the summer feeding distribution of Northeast Atlantic mackerel in the Nordic Seas began expanding into new areas far to the north and west. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Fisheries and Oceans Canada, Institute of Marine Research (Havforskningsinstituttet), Norway, Scottish Government, California Academy of Sciences (Eschmeyer's Catalog of Fishes) — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Fisheries and Oceans Canada
Institute of Marine Research (Havforskningsinstituttet), Norway
Scottish Government
California Academy of Sciences (Eschmeyer's Catalog of Fishes)
|
| Habitat | Pelagic in cold and temperate waters over the continental shelf, near the surface; marine and brackish. Depth range 0–1000 m, usually 0–200 m. Prefers a narrow temperature range of 7 to 16°C.Around the British Isles and Ireland it is usually found at depths of less than 200 m and is more abundant on the shelf edges in winter. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), FishBase (Froese & Pauly, eds.), Fisheries and Oceans Canada, Marine Life Information Network (MarLIN), Marine Biological Association of the UK — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
FishBase (Froese & Pauly, eds.)
Fisheries and Oceans Canada
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
|
| Diet | Zooplankton, especially crustaceans such as copepods, krill and shrimp, plus fish larvae and small fish; also squid and some ascidians (sac-like filter feeders).In Northeast Atlantic accounts, named fish prey include capelin, sandeel, herring, sprat and Norway pout; crustaceans (shrimps) make up almost half of the food by weight and juvenile fish the rest; feeding varies with season, area and fish size and nearly stops in winter; and herring are the main competitors for prey. Mackerel there seem very opportunistic in where they feed, exploiting any available ocean area from one year to the next. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Institute of Marine Research (Havforskningsinstituttet), Norway, Scottish Government, FishBase (Froese & Pauly, eds.) — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Institute of Marine Research (Havforskningsinstituttet), Norway
Scottish Government
Scottish Government
FishBase (Froese & Pauly, eds.)
|
| Body size | Maximum length about 45 cm, 16 ½ inches, 60.0 cm fork length, over 60 cm, or 65 cm. Common length 30.0 cm fork length.sources disagreeOnly the fork-length (FL) figures name the measure. Young grow fast: they can reach 20 cm by November of their first year in a Canadian account, and 22 cm after one year and 30 cm after two years in a Northeast Atlantic account. | Sources disagree · Fisheries and Oceans Canada, NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), FishBase (Froese & Pauly, eds.), Marine Life Information Network (MarLIN), Marine Biological Association of the UK, Institute of Marine Research (Havforskningsinstituttet), Norway, Scottish Government — how we knowWhat each reading says
Maximum length differs: about 45 cm in a Canadian account and 16 ½ inches in a U.S. account, against 60.0 cm fork length in a global database, over 60 cm in a British Isles review and 65 cm in a Norwegian account. Fisheries and Oceans Canada
NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
FishBase (Froese & Pauly, eds.)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
Institute of Marine Research (Havforskningsinstituttet), Norway
Scottish Government
|
| Body mass | Maximum 800 grams, 2.2 pounds, 3.4 kg or 3.5 kg; usually less than 1 kg.sources disagreeThe 800-gram and 2.2-pound maxima come from Canadian and U.S. accounts; 3.4 kg is the maximum published weight in a global database and is also given by a British review; 3.5 kg and 'usually less than 1 kg' come from a Norwegian (Northeast Atlantic) account. | Sources disagree · Fisheries and Oceans Canada, NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), FishBase (Froese & Pauly, eds.), Marine Life Information Network (MarLIN), Marine Biological Association of the UK, Institute of Marine Research (Havforskningsinstituttet), Norway — how we knowWhat each reading says
Maximum weight differs: up to 800 grams in a Canadian account and 2.2 pounds in a U.S. account, against 3.4 kg as the maximum published weight and in a British Isles review, and 3.5 kg in a Norwegian account. Fisheries and Oceans Canada
NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
FishBase (Froese & Pauly, eds.)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
Institute of Marine Research (Havforskningsinstituttet), Norway
|
| Lifespan | Maximum age 17, 20 or 25 years; usually not older than 10–15 years.sources disagreeThe 17-year figure is a maximum reported age. Another account says it can live for over 15 years. The 25-year maximum and the 10–15-year typical age come from a Norwegian (Northeast Atlantic) account, which also says longevity is seldom more than 25 years. No captive lifespan was found. | Sources disagree · FishBase (Froese & Pauly, eds.), NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Institute of Marine Research (Havforskningsinstituttet), Norway, Fisheries and Oceans Canada — how we knowWhat each reading says
Maximum age differs: 17 years (maximum reported age) in a global database, up to 20 years in a U.S. account, and up to 25 years in a Norwegian account that also gives longevity as seldom more than 25 years. FishBase (Froese & Pauly, eds.)
NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Institute of Marine Research (Havforskningsinstituttet), Norway
Fisheries and Oceans Canada
|
| Social structure | Schooling: forms large schools near the surface, in the upper water column, primarily as a defense against predation; shoals up to 9 km long, 4 km wide and 40 m deep have been reported. After spawning, adults feed very actively while moving around in small shoals. | Matches source · Scottish Government, FishBase (Froese & Pauly, eds.), Marine Life Information Network (MarLIN), Marine Biological Association of the UK, NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration) — how we knowScottish Government
FishBase (Froese & Pauly, eds.)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
|
| Reproduction | Batch spawner. Northwest Atlantic: April–May (southern group) and June–July (northern group, mainly the southern Gulf of St. Lawrence). Northeast Atlantic: March–July, mainly south and west of the UK and Ireland; North Sea, May–July.sources disagreeEggs float near the surface. Typically mature by 2 or 3 years. The southern group spawns primarily in the Mid-Atlantic Bight by one account, or off southern New England and in the western Gulf of Maine by another; both Northwest Atlantic groups typically spawn 10 to 30 miles offshore. In the northeast, spawning begins in the Celtic Sea, Bay of Biscay and Cantabrian Sea and moves north to the Faroe Islands and Norwegian coast by June; another account places North Sea spawning later, around June/July. | Sources disagree · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Fisheries and Oceans Canada, Scottish Government, FishBase (Froese & Pauly, eds.) — how we knowWhat each reading says
Egg hatching time is 4 to 7 ½ days in one account and 1 to 6 days in another, both depending on water temperature. Egg numbers and batches also differ: a U.S. account gives 285,000 to almost 2 million eggs per female, depending on size, released in five to seven batches, while a Scottish account of Northeast Atlantic fish gives about twenty batches and around 250,000 eggs for an average-sized fish. NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Fisheries and Oceans Canada
Scottish Government
Scottish Government
FishBase (Froese & Pauly, eds.)
|
| Movement | Oceanodromous, with vast annual feeding and spawning migrations. In the northeast, fish migrate south to spawn, then north and west to feed in the Nordic Seas; in the northwest, the northern contingent feeds in Canadian waters after spawning, then moves south into deeper water.Winters in deeper water (in the northeast, mainly near the northern North Sea shelf edge); moves inshore in spring at 11 to 14°C. Some northeast adults gather in February/March before heading south. When the stock was large, feeding fish reached Greenland waters and the Svalbard area. Northern-contingent feeding in Atlantic Canada and Quebec waters lasts from the end of July to October or November. No trans-Atlantic migration is known. | Matches source · Scottish Government, Fisheries and Oceans Canada, FishBase (Froese & Pauly, eds.) — how we knowScottish Government
Fisheries and Oceans Canada
FishBase (Froese & Pauly, eds.)
Scottish Government
|
| Human interaction | Supports one of the biggest fisheries in the North Atlantic, with recent international catches of approximately 1 million tonnes and a first-sale value over 10 billion NOK; a gamefish; in eastern Canada, commercial, bait, recreational and Indigenous fisheries. Harmless to people.Managed in the Northeast Atlantic as one stock; unilateral quotas have led to catches 39% above scientific advice on average since 2010, and the stock was estimated below MSY Btrigger and Blim in 2025. The North Sea stock fell dramatically in the 1960s from direct overfishing. Canadian landings have been below 12,000 t since 2011; a significant quantity of the commercial catch is used as bait. | Matches source · Institute of Marine Research (Havforskningsinstituttet), Norway, Fisheries and Oceans Canada, Scottish Government, FishBase (Froese & Pauly, eds.) — how we knowInstitute of Marine Research (Havforskningsinstituttet), Norway
Fisheries and Oceans Canada
Scottish Government
FishBase (Froese & Pauly, eds.)
|
| Conservation status | Least Concern (LC), global assessment, 2023 | 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, range, habitat, diet, body-size, weight, lifespan, social-structure, reproduction (Appearance, Biology and Where They Live sections only). Retrieved 2026-10-20.Limitations: Species Directory page (last updated 10/01/2026) written for U.S. stocks; only its Appearance, Biology and Where They Live sections were used, not its U.S. stock, management, regulation or seafood text. Length measure not named. Its maximum size (16 ½ inches, 2.2 pounds), maximum age (20 years) and egg-hatching time (4 to 7 ½ days) differ from other accounts.
- GovernmentFisheries and Oceans CanadaSupports: identification, range, habitat, body-size, weight, lifespan, reproduction, movement, human-interaction. Retrieved 2026-10-20.Limitations: Aquatic species profile (date modified 2025-07-04) centered on the Northwest Atlantic and Canada's northern contingent; its maximum size (about 45 cm) and weight (up to 800 grams) are not tied to a region in the text and are lower than other accounts; length measure not named; Canadian landings table runs only to 2022 (preliminary).
- GovernmentInstitute of Marine Research (Havforskningsinstituttet), NorwaySupports: identification, range, diet, body-size, weight, lifespan, human-interaction. Retrieved 2026-10-20.Limitations: Topic page (published 02.06.2022) on Northeast Atlantic mackerel; its fact box gives a maximum of 65 cm and 3.5 kg without naming the length measure, and gives maximum age as 'Up to 25 years' but longevity as 'Seldom more than 25 years'. Fishery figures are for the Northeast Atlantic; the euro value is not quoted because the page text carries it as an unrendered entity (the NOK figure is used).
- GovernmentScottish GovernmentSupports: range, diet, social-structure, reproduction, movement, human-interaction. Retrieved 2026-10-20.Limitations: Background chapter of the Northern Shelf Mackerel Fisheries Management Plan (Marine Directorate, published 22 July 2026) for Northeast Atlantic mackerel; UK fleet, gear and landings figures were not used.
- GovernmentScottish GovernmentSupports: diet, body-size, reproduction, movement. Retrieved 2026-10-20.Limitations: Fish and Shellfish Stocks: 2015 Edition (published 18 May 2015), Northeast Atlantic mackerel chapter; its Biology section describes the North Sea and western stocks caught by the Scottish fleet. Its 2015 quota and ICES advice figures were not used; its count of about twenty egg batches per season differs from a U.S. account (five to seven).
- ReferenceFishBase (Froese & Pauly, eds.)Supports: identification, habitat, diet, body-size, weight, lifespan, social-structure, reproduction, movement, human-interaction. Retrieved 2026-10-20.Limitations: Compiled species summary (page footer: last modified 20 July 2016) citing many references; lengths are fork length (FL); maximum weight and age are single referenced records not tied to a region. Its 'Mainly diurnal' note is not used because no activity claim is made (cap). Its trade and cooking sentence was not used.
- ReferenceMarine Life Information Network (MarLIN), Marine Biological Association of the UKSupports: identification, habitat, body-size, weight, social-structure. Retrieved 2026-10-20.Limitations: Key Information Review researched by Morvan Barnes (2008; last updated 27/03/2008), British Isles focus; length measure not named. Its sentence on finlets distinguishing Scomber japonicus was not used.
- ReferenceCalifornia Academy of Sciences (Eschmeyer's Catalog of Fishes)Supports: identity (accepted name, authorship, synonyms); range (distribution summary). Retrieved 2026-10-20.Limitations: Taxonomic catalogue (online version updated 21 Sep. 2026); its distribution is a one-line summary and does not separate native from other occurrence.
- 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 — Atlantic Mackerel
Why do Atlantic mackerel have to keep swimming?
To breathe: Atlantic mackerel must keep swimming in order to breathe. They also have no swim bladder.
How big do Atlantic mackerel get?
Maximum length is given as about 45 cm or 16 ½ inches in North American accounts and as 60.0 cm fork length, over 60 cm or 65 cm in global and European ones. A Norwegian account says they usually weigh less than 1 kg.
Where do Atlantic mackerel live?
On both sides of the North Atlantic: from Labrador to North Carolina in the west, and from Morocco to the northern Norwegian Sea in the east, including the North, Baltic, Mediterranean and Black seas.
What do Atlantic mackerel eat?
Zooplankton, especially crustaceans such as copepods, krill and shrimp, plus fish larvae, small fish and squid. Northeast Atlantic accounts say they feed very little in winter.
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) — Atlantic mackerel species page — identification, range, habitat, diet, body-size, weight, lifespan, social-structure, reproduction (Appearance, Biology and Where They Live sections only)
- GovernmentFisheries and Oceans Canada — Atlantic mackerel species profile — identification, range, habitat, body-size, weight, lifespan, reproduction, movement, human-interaction
- GovernmentInstitute of Marine Research (Havforskningsinstituttet), Norway — Mackerel (Institute of Marine Research, Norway) — identification, range, diet, body-size, weight, lifespan, human-interaction
- GovernmentScottish Government — Northern shelf mackerel fisheries management plan: background — range, diet, social-structure, reproduction, movement, human-interaction
- GovernmentScottish Government — Fish and shellfish stocks 2015: mackerel — diet, body-size, reproduction, movement
- ReferenceFishBase (Froese & Pauly, eds.) — Scomber scombrus species summary — identification, habitat, diet, body-size, weight, lifespan, social-structure, reproduction, movement, human-interaction
- ReferenceMarine Life Information Network (MarLIN), Marine Biological Association of the UK — Atlantic mackerel, Marine Life Information Network — identification, habitat, body-size, weight, social-structure
- ReferenceCalifornia Academy of Sciences (Eschmeyer's Catalog of Fishes) — Scomber scombrus, Eschmeyer's Catalog of Fishes — identity (accepted name, authorship, synonyms); range (distribution summary)
- ReferenceIUCN Red List — Scomber scombrus assessment — The global Red List category and the year of the assessment