There are about 30 fish that are sold as various types of mackerel. Among these are the so-called “true mackerels” like the Atlantic mackerel (scomber scombrus), the Spanish mackerels like king mackerel (Scomberomorus cavalla), and many other unrelated fish with mackerel like characteristics. Mackerel are smaller and slimmer than tuna but have similar streamlined bodies, forked tails, silver or white bellies and darker, often spotted backs. Mackerel often swim in enormous migratory schools and depending upon their size, can act as a predator or prey.
How They are Caught
The historically important Atlantic mackerel is still a major food fish, but only make up a small portion of the total catch. The 2021 assessment by NOAA states that Atlantic mackerel are currently overfished but are part of a rebuilding program so current quotas are low. Most commercially caught Atlantic Mackerel are harvested by mid-water trawl nets but some are caught using jigging systems or gillnet. Spanish mackerel have been caught more in recent years, but still about half of the Atlantic mackerel catch. The related Atlantic chub mackerel is also an important food fish throughout its wide range but usually caught with bottom trawls. Meanwhile two Pacific species, the Pacific chub (Scomber japonicus) and Chilean jack mackerel (Trachurus murphyi) are today some of the most important food fishes worldwide. American fishermen catch Pacific mackerel mainly using round haul nets.
There is no hiding an old mackerel, they lose firmness and brightness pretty quickly unless handled well. Look for whole fresh mackerel that are firm and stiff, with a shiny skin and unclouded eyes. If they were not freshly taken out of the water, then they need to be on lots of ice. Flash frozen mackerel can also be found, but quality depends upon how fast the fish was frozen. The larger mid-water trawlers can usually freeze them at sea to ensure freshness. If choosing “previously frozen” mackerel from a fish counter, the same rules for firmness and color apply. Like other small oily fish, mackerel spoils quickly, which can lead to a serious bacterial infection known as scombroid poisoning if not properly handled.
Mackerel species have fatty, oily flesh that ranges from whitish to dark red with a rich flavor that is not overpowering. There are many ways to prepare fresh mackerel, from very basic to high-end gourmet, but are perfect for grilling or broiling, either whole or in fillets.
Due to mackerel’s quick spoilage, they were traditionally pickled, salted or smoked if eaten beyond the immediate coast. Smoked mackerel is still a great way to enjoy the fish and can be used just like smoked salmon. Mackerel of all stripes are often loaded with Omega-3s, all are wild caught and most species are low in mercury.
The most accessible way of trying mackerel and one of the most affordable is canned or tinned conservas. Most supermarkets have at least one major brand of boneless, skinless mackerel (usually chub) fillets in olive oil or other sauces. They are very tasty, sustainable and a healthy, low-mercury alternative to canned tuna.
Substitutions When Cooking
When substituting for mackerel look for an oily fish with relatively thin fillets. Herring, large sardines/pilchards, even a light fleshed trout could work as substitutes. Tail or end sections of salmon or steelhead could make a tasty twist on recipes that call for mackerel fillets. The reverse is true as well, mackerel makes for a good alternative to various other oily fish, from salmon to tuna.