Atlantic Mackerel

The Atlantic mackerel (Scomber scombrus) is a small, fast-swimming member of the tuna and mackerel family Scombridae, native to the North Atlantic Ocean. It occurs on both the North American and European coasts, forming huge migratory schools that move seasonally between spawning and feeding grounds. Atlantic mackerel is an important forage species, supporting numerous seabirds, marine mammals, and larger predatory fish. It is also one of the most commercially significant pelagic species in the North Atlantic. Populations undergo large natural fluctuations, and management is closely monitored across international fisheries bodies. The species is currently considered stable across most of its range.

Atlantic mackerel are streamlined, torpedo-shaped fish built for speed.

• Back: iridescent blue-green with 20-30 dark, irregular wavy vertical stripes
• Belly: silvery-white, unmarked
• Body: fusiform, tapering sharply toward a narrow caudal peduncle
• Fins: two well-separated dorsal fins, followed by 5 small finlets near the tail
• Scales: very small, no lateral line scutes
• Size: typically 30-40 cm

The wavy dorsal stripe pattern and lack of a swim bladder distinguish it from chub/Pacific mackerel, which show more spotted, irregular blotching on the lower flanks.

Atlantic mackerel inhabit cool to temperate continental shelf waters on both sides of the North Atlantic, from Labrador and the Gulf of St. Lawrence south to North Carolina in the west, and from Iceland and Norway south to the Mediterranean and Northwest Africa in the east. They are pelagic, typically found from the surface down to about 200 m, moving inshore in warmer months and offshore to deeper, warmer water in winter. Schools track sea temperature closely, generally preferring waters between 8-14°C, and undertake extensive seasonal migrations tied to spawning and feeding cycles.

Atlantic mackerel are highly gregarious, forming enormous, fast-moving schools that can extend for kilometers, providing protection from predators. They are active daytime feeders, filter-feeding on plankton when prey is dense and actively hunting small fish and crustaceans otherwise. Schools undertake long seasonal migrations, moving to warmer coastal waters in spring and summer to spawn and feed, then retreating to deeper offshore waters in winter. Spawning occurs in batches over an extended season, with females releasing large numbers of buoyant eggs that drift with currents. As a key forage species, mackerel support extensive food webs linking plankton to top predators like tuna, sharks, and seabirds.