The Atlantic mackerel (Scomber scombrus), also known as Boston mackerel, Norwegian mackerel, Scottish mackerel or just masckerel, is a pelagic schooling species of mackerel found on both sides of the North Atlantic and Mediterranean Sea. It is by far the most common of the 10 species of Scombridae caught in British waters. It is extremely common in huge shoals migrating towards the coast to feed on small fish and prawns during the summer. Abundant in cold and temperate shelf areas, it schools near the ocean surface. It overwinters in deeper waters, but moves closer to shore in spring when water temperatures range between 11–14 °C (52–57 °F). They can live to 20 years of age and can reach sizes of up to 47 cm (19 in). Most Atlantic mackerel are sexually mature by the age of 3 years.
Taxonomy and phylogeny
The Atlantic mackerel was first described in 1758 by Swedish zoologist Carl Linnaeus in his 10th edition of Systema Naturae. Because of its wide distribution, it was described 6 more times by 5 different scientists between 1814 and 1863. Its generic and specific names both come from the Greek word skombros meaning "tunny" or "mackerel."
The Atlantic mackerel has an elongate, rounded body with a small, conical snout. The eyes are large and covered by an adipose eyelid, while the teeth are small. Scales are small, with the exceptions of those immediately posterior to the head and around the pectoral fins. Its body is steel-blue dorsally with wavy black lines running perpendicular to the fish's length. The rest of its body is silvery-white to yellow and may have darker splotches. It can reach sizes of up to 60 cm (24 in) and has a common length of 30 cm (12 in). Its maximum published weight is 3.4 kg (7.5 lb).
Distribution and habitat
The Atlantic mackerel's native range in the western Atlantic extends from Labrador, Canada to Cape Lookout, North Carolina. In the eastern Atlantic, it can be found from Iceland to as far south as Mauritania. It is also found in the Mediterranean, Black, and Baltic Seas. Its latitudinal range is 70°N-25°N and its longitudinal range is 77°W-42°E. Its preferred water temperature is above 8 °C (46 °F), but they are common in waters as cold as 7 °C (45 °F) and have rarely been found in 4.5 °C (40.1 °F) conditions. Their depth range extends from the surface to as deep as 1,000 m (3,300 ft), but they are usually found above 200 m (660 ft).
Atlantic mackerel are migratory fish, spending the spring and summer closer to shore about 32–161 km (20–100 mi) out, with juveniles moving closer in to shore than adults. Occasionally, fish will even enter harbors, and those that do are usually juveniles. In the fall and winter they move farther out and farther south to the warmer waters on the edge of the continental shelf. They first come in to land in North America in April at the southern end of their range, but are found along the coast through their entire range by July. They start moving back out to sea again in September and are completely gone from the coast by December. Food availability increases greatly during the summer, and fish reach a peak for fat tissue in August, a mere four months after their lowest point in April.
Biology and ecology
Atlantic mackerel form large schools near the ocean surface during all seasons but winter. Schools tend to be formed based on the size of the fish and the fish's ability to see is an important factor in their ability to stick together. When feeding on larger prey, schools tend to break down into shoals, and fish find food on their own. When consuming plankton, however, the fish opened their mouths as wide as possible, extended their operculums, and formed a tightly-packed school that acted like a series of miniature tow nets. Spaced only about the diameter of a single fish's mouth apart, their formation greatly reduced the ability of plankton to evade capture, as a plankton darting out of the jaws of one fish would likely end up in the jaws of another. Copepods make up the majority of the fish's diet and of the copepods they eat, Calanus finmarchicus is the most prominent. Schools of mackerel tend to be composed of fish of similar size and swimming ability, the latter being dependent on the former, as larger fish have a greater ratio of muscle mass to surface area. Atlantic mackerel must always be in motion to receive enough oxygen through the gills.
Like other mackerels, reproduction in the Atlantic mackerel is oviparous. Spawning occurs day or night in the spring and summer months, primarily within 48 km (30 mi) of shore, though it can occur as far out as 130 km (81 mi). A single female can spawn as many as 450,000 eggs in a spawning season. Eggs mature in batches over the course of a week and are pelagic once released, remaning within 15–25 m (49–82 ft) of the surface. Time to hatching is dependent on the water temperature, and ranges from 2 days at 21 °C (70 °F) to 8.5 days at 10 °C (50 °F). Most eggs are spawned in waters 9–12 °C (48–54 °F) in temperaure, and as such the majority of eggs hatch in about a week. Eggs are anywhere from 1.0–1.3 mm (0.039–0.051 in) in size, trending towards smaller as the spawning season goes on. Larvae undergo three developmental stages: the yolk sac stage, the larval stage, and the post-larval stage. Larvae are 3 mm (0.12 in) when they hatch and feed on the yolk sac for about 5 days. During the larval stage, which lasts about a month, larvae grow to 10 mm (0.39 in) in length. They are largely incapable of swimming, instead floating with the current. During the post-larval stage, which occurs over the next 40 days and during which the fish reaches 50 mm (2.0 in) in length, it swims to the surface at night and down to deeper waters during the day. At the end of the post-larval stage, juveniles resemble an adult mackerel in all but size. Schooling behavior occurs around this time.
Sexual maturity is reached at around 2 years of age, though some fish may reproduce a season earlier or a season later. Though some fish are sexually mature at 25 cm (9.8 in) in length, even by 34 cm (13 in) only about half of females will be ready to reproduce. At 37 cm (15 in), 90% of fish are capable of reproduction. An atlantic mackerel can live for up to 17 years and attain a length of 60 cm (24 in) and a weight of 3.4 kg (7.5 lb).
There are two known stocks of Atlantic mackerel in the northeast Atlantic: one in the North Sea and one around the British Isles. There two more distinct stocks in the western Atlantic: northern and southern stocks, each of which occupies different territories during the stages of their migration.
|Nutritional value per 100 g (3.5 oz)|
|Energy||858 kJ (205 kcal)|
|Vitamin A equiv.||
|Percentages are roughly approximated using US recommendations for adults.
Source: USDA Nutrient Database
Atlantic mackerel are sought after for food either cooked or as sashimi and consist mostly of red meat with a strong taste desirable to some consumers. The fish is extremely high in vitamin B12 as well as omega 3 (a class of fatty acids) and contains nearly twice as much of the latter per unit weight as salmon. Unlike the King and Spanish species, Northern Atlantic mackerel are very low in mercury, and can be eaten at least twice a week according to EPA guidelines.
Mackerel is an excellent source of phosphatidylserine, as it contains about 480 mg / 100 grams by weight. Phosphatidylserine is under investigation to mitigate symptoms of ADHD and Alzheimer's disease.[by whom?]
A smoked Atlantic mackerel
|External identifiers for Scomber scombrus|
|Encyclopedia of Life||46324676|
|Also found in: Wikispecies, FishBase|
- Collette, B.; A. Boustany; K. E. Carpenter; A. Di Natale; W. Fox; J. Graves; M. Juan Jorda; O. Kada; R. Nelson; H. Oxenford (2011). "Scomber scombrus". IUCN Red List of Threatened Species. Version 2010.1. International Union for Conservation of Nature. Retrieved 19 February 2017.
- Froese, Rainer and Pauly, Daniel, eds. (2017). "Scomber scombrus" in FishBase. February 2017 version.
- "Scomber scombrus". FAO.org. Food and Agriculture Organization of the United Nations. Retrieved 19 February 2017.
- Sette, Oscar Elton (1952). "Biology of the Atlantic mackerel (Scomber scombrus) of North America: Part II-Migrations and Habits" (pdf). Fishery Bulletin of the Fish and Wildlife Service. 51: 251–358.
- Sette, Oscar Elton (1943). "Biology of the Atlantic Mackerel (Scomber scombrus) of North America: Part I:Early life history, including the growth, drift, and mortality of the egg and larval populations" (pdf). Fishery Bulletin of the Fish and Wildlife Service. 50: 149–237.
- Atlantic mackerel NOAA FishWatch. Retrieved 11 November 2012.
- Media related to Scomber scombrus at Wikimedia Commons
- gma.org - atlantic mackerel information
- Blue Ocean Institute - Atlantic Mackerel fishing and conservation report
- EDF Report on Mackerel - Atlantic Mackerel conservation and contamination report