Fish of the Week - Mackerel

Mackerel is a common name applied to a number of different species of pelagic fish, mostly, but not

Some species of mackerel migrate in schools

exclusively, from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment.
Mackerel typically have vertical stripes on their backs and deeply forked tails. Many species are restricted in their distribution ranges, and live in separate populations or fish stocks based on geography. Some stocks migrate in large schools along the coast to suitable spawning grounds, where they spawn in fairly shallow waters. After spawning they return the way they came, in smaller schools, to suitable feeding grounds often near an area of upwelling. From there they may move offshore into deeper waters and spend the winter in relative inactivity. Other stocks migrate across oceans.
Smaller mackerel are forage fish for larger predators, including larger mackerel. Flocks of seabirds, as well as whales, dolphins, sharks and schools of larger fish such as tuna and marlin follow mackerel schools and attack them in sophisticated and cooperative ways. Mackerel is high in omega-3 oils and is intensively harvested by humans. In 2009, over five millions tonnes were landed by commercial fishermen (see graph on the right). Sport fisherman value the fighting abilities of the king mackerel.




Over thirty different species, principally belonging to the family Scombridae, are commonly referred to as mackerel. The term "mackerel" means "marked" or "spotted." The term mackerel derives from the Old French maquerel, c.1300, meaning a pimp or procurer. The connection is not altogether clear, but mackerel spawn enthusiastically in shoals near the coast, and medieval ideas on animal procreation were creative.




About 21 species in the family Scombridae are commonly called mackerel. The type species for the scombroid mackerel is the Atlantic mackerel, Scomber scombrus. Until recently, it was thought that Atlantic chub mackerel and Indo-Pacific chub mackerel were subspecies of the same species. In 1999 Collette established, on molecular and morphological considerations, that these are separate species. Mackerel are smaller with shorter life cycles than their close relatives, the tuna, which are also members of the same family.




The true mackerels belong to the tribe Scombrini. The tribe consists of seven species, each belonging to one of two genera: Scomber and Rastrelliger. The Spanish mackerels belong to the tribe Scomberomorini, and is the "sister tribe" of the true mackerels. This tribe consists of 21 species in all – 18 of those are classified into the genus Scomberomorus, two into Grammatorcynus, and a single species into the monotypic genus Acanthocybium. In addition, a number of species with mackerel-like characteristics in the families Carangidae, Hexagrammidae and Gempylidae are commonly referred to as mackerel. There has been some confusion between the Pacific jack mackerel (Trachurus symmetricus) and the heavily harvested Chilean jack mackerel (Trachurus murphyi). These have been thought at times to be the same species, but are now recognised as separate species.




The term mackerel is also used as a modifier in the common names of other fish, sometimes indicating the fish has vertical stripes similar to a scombroid mackerel:
* Mackerel icefish – Champsocephalus gunnari
* Mackerel pike – Cololabis saira
* Mackerel scad – Decapterus macarellus
* Mackerel shark – several species
* Sharp-nose mackerel shark – Isurus oxyrinchus
* Mackerel tuna – Euthynnus affinis
* Mackerel tail goldfish – Carassius auratus
By extension, the term is applied also to other species such as the mackerel tabby cat, and to inanimate objects such as the altocumulus mackerel sky cloud formation.




Most mackerel species have restricted distribution ranges.
* Atlantic Spanish mackerel (Scomberomorus maculatus) occupy the waters off the east coast of North America from the Cape Cod area south to the Yucatan Peninsula. Its population is considered to include two fish stocks, defined by geography. As summer approaches, one stock moves in large schools north from Florida up the coast to spawn in shallow waters off the New England coast. It then returns to winter in deeper waters off Florida. The other stock migrates in large schools along the coast from Mexico to spawn in shallow waters of the Gulf of Mexico off Texas. It then returns to winter in deeper waters off the Mexican coast. These stocks are managed separately, even though genetically they are identical.

* The Atlantic mackerel (Scomber scombrus) is a coastal species found only in the north Atlantic. The stock on the west side of the Atlantic is largely independent of the stock on the east side. The stock on the east Atlantic currently operates as three separate stocks, the southern, western and North Sea stocks, each with their own migration patterns. Some mixing of the east Atlantic stocks takes place in feeding grounds towards the north, but there is almost no mixing between the east and west Atlantic stocks.

* Another common coastal species, the chub mackerel (Scomber japonicus), is absent from the Atlantic Ocean but is widespread across both hemispheres in the Pacific, where its migration patterns are somewhat similar to those of Atlantic mackerel. In the northern hemisphere, chub mackerel migrate northwards in the summer to feeding grounds, and southwards in the winter when they spawn in relatively shallow waters. In the southern hemisphere the migrations are reversed. After spawning, some stocks migrate down the continental slope to deeper water and spend the rest of the winter in relative inactivity.

* The Chilean jack mackerel (Trachurus murphyi), the most intensively harvested mackerel-like species, is

Chilean jack mackerel have been overfished 

found in the south Pacific from West Australia to the coasts of Chile and Peru. A sister species, the Pacific jack mackerel (Trachurus symmetricus), is found in the north Pacific. The Chilean jack mackerel occurs along the coasts in upwelling areas, but also migrates across the open ocean. Its abundance can fluctuate markedly as ocean conditions change, and is particularly affected by the El Nino.

Three species of jack mackerels are found in coastal waters around New Zealand; the Australasian, Chilean and Pacific jack mackerels. They are mainly captured using purse seine nets, and are managed as a single stock that includes multiple species.

Some mackerel species migrate vertically. Adult snake mackerels conduct a diel vertical migration, staying in deeper water during the day and rising to the surface at night to feed. The young and juveniles also migrate vertically but in the opposite direction, staying near the surface during the day and moving deeper at night. This species feeds on squid, pelagic crustaceans, lanternfishes, flying fishes, sauries and other mackerel. It is in turn preyed upon by tuna and marlin.




Chub mackerel, Scomber japonicus, are the most intensively fished scombroid mackerel. As can be seen from the graph on the right, they account for about half the total capture production of scombroid mackerels. As a species they are easily confused with Atlantic mackerel. Chub mackerel migrate long distances in oceans and across the Mediterranean. They can be caught with drift nets and suitable trawls, but are most usually caught with surround nets at night by attracting them with lampara lamps.
The remaining catch of scombroid mackerels is divided equally between the Atlantic mackerel and all other scombroid mackerels. Just two species account for about 75% of the total catch of scombroid mackerels.
Chilean jack mackerel are the most commonly fished non-scombroid mackerel, fished as heavily as chub mackerel. The species has been overfished, and its fishery may now be in danger of collapsing.
Smaller mackerel behave like herrings, and are captured in similar ways. Fish species like these, which school near the surface, can be caught efficiently by purse seining. Huge purse seiner vessels use spotter planes to locate the schooling fish. Then they close in using sophisticated sonar to track the shape of the shoal. Entire schools are then encircled with fast auxiliary boats which deploy purse seine nets as they speed around the school.
Suitably designed trollers can also catch mackerels effectively when they swim near the surface. Trollers typically have several long booms which they lift and drop with "topping lifts". They haul their lines with electric or hydraulic reels. Fish aggregating devices are also used to target mackerel.




Mackerel is an important food fish that is consumed worldwide. As an oily fish, it is a rich source of omega-3

Atlantic mackerel on ice at a fishmongers

fatty acids. The flesh of mackerel spoils quickly, especially in the tropics, and can cause scombroid food poisoning. Accordingly, it should be eaten on the day of capture, unless properly refrigerated or cured.
Mackerel preservation is not simple. Before the 19th-century development of canning and the widespread availability of refrigeration, salting and smoking were the principal preservation methods available. Historically in England, this fish was not preserved, but was consumed only in its fresh form. However, spoilage was common, leading the authors of The Cambridge Economic History of Europe to remark: "There are more references to stinking mackerel in English literature than to any other fish!" In 2013,concerns were raised that mackerel may not have been as plentiful a fish as had previously been considered. In France mackerel was traditionally pickled with large amounts of salt, which allowed it to be sold widely across the country.