American Oceans

Atlantic Mackerel

The Atlantic Mackerel, or Scomber scombrus, is a species of mackerel found in the temperate waters of the northern Atlantic Ocean, Black Sea, and the Mediterranean Sea.

Atlantic Mackerel or Scomber scombrus

It is a medium-sized mackerel widely consumed worldwide because of its strong flavor and high Omega-3 fatty acid content.

Also known as the Boston Mackerel, Norwegian Mackerel, Scottish mackerel, or just mackerel, it is one of the most common species of fish and is widely spread since it migrates far and wide each year.

Known across the USA as a beginner catch for those trying out recreational fishing, this animal is actually a unique and fascinating creature. Read on to learn more about the Atlantic Mackerel!

Characteristics & Appearance

The Atlantic Mackerel is widely recognized for its distinctive coloring and length, which fishermen look for from the shore. There are many other interesting physical characteristics of this common fish.

Weight & Length

The Atlantic Mackerel has a long, fusiform body. Fusiform describes a spindle-shaped type of fish whose body tapers at the head and tail. They usually weigh about 6 pounds and have an average length of 12 inches. 

Physical Characteristics & Color

The Atlantic Mackerel is recognizable for its back scales, which transition from a steel blue to an aquamarine closer to its top. It has wavy black lines that cover its back and silver-white lines on its stomach.

This mackerel has two pointed dorsal fins spaced far apart, and two smaller pectoral fins also spaced far apart.

If you look closely at one, you’ll also see 4-6 much smaller dorsal fins accompanying the larger ones. They can retract these dorsal fins into a groove in their body to swim faster.

The Atlantic Mackerel’s snout is very long and slightly pointed at the end, and its tail has a fin that is short but noticeably broad compared to its narrow body.

Atlantic Mackerel have large, protruding eyes covered by a transparent eyelid common among mackerel species.

They have small, sharp teeth that are conical, meaning they are spaced far apart within the mouth.

Lifespan & Reproduction

Atlantic Mackerel reach sexual maturity very early in life, around 2-3 years old. They can live up to 20 years, but their average lifespan is about 17.

The ability of female fish to reproduce is based more on size than age. About half of females can reproduce once they reach 13 inches, and 90% can reproduce when they reach 15 inches.

The Atlantic Mackerel is oviparous, meaning it lays eggs that mature and hatch outside the body.

The mackerel spawn and lay their eggs usually around 30 miles from shore, although they have been observed reproducing as far out as 80 miles.

A single female can spawn as many as 450,000 eggs each season, which mature and hatch over the course of just one week.

The hatchlings stay in the larva stage for about a month, and during that time cannot swim, floating with the current instead.

Habitat

The western swimming Atlantic Mackerel has a native range stretching from Labrador, Canada to North Carolina.

In the eastern Atlantic, this species is as far north as Iceland and as far south as Mauritania. Although called the Atlantic Mackerel, it also extends beyond the ocean and can be found in several seas.

Atlantic Mackerel are deep swimmers and can swim anywhere from 600-3,000 feet into the water. However, they are commonly found in vast schools close to the surface.

Where Do Atlantic Mackerel Live?

The Atlantic Mackerel is a migratory species. During the spring and summer, they can be found closer to shore, usually fewer than 100 miles out. During the fall and winter, they move to warmer waters on the edge of the continental shelf.

Atlantic Mackerel are some of the fastest swimmers in the Atlantic and need to keep in constant motion to get enough oxygen. Unlike other mackerel species, they don’t leap out of the water unless escaping a predator.

Food & Diet

The Atlantic Mackerel is a predatory fish with similar feeding patterns to tuna. Their diet varies throughout the year in both size and species.

They hunt in massive groups when catching their prey. This hunting style allows them to gang up and more efficiently catch fish while also acting as a defensive practice.

What Do Atlantic Mackerel Eat?

The Atlantic Mackerel is a skilled predator, especially because of its ability to change strategies based on the size and location of its prey.

The smallest prey the Mackerel will eat is plankton, where they will form large and tight aggregations, creating a kind of net to swallow thousands of plankton at once. This is a similar technique to that of a whale with baleen plates.

The next size of Atlantic Mackerel prey consists of shrimp, eels, and small or juvenile fish. When they hunt these species, they also form large predatory groups called shoals, which sometimes number in the thousands.

The Mackerel use these shoals to surround large schools of fish or eels to trap them. This technique is a fascinating example of the food chain at work.

When they are trapped, the group of prey will swim in a frenzy, creating a ‘boiling’ effect on the surface of the water.

This visual attracts birds of prey, which in turn tells experienced fishermen where to bring their boats.

Occasionally, Atlantic Mackerel will hunt larger fish, which they do in much smaller groups or even individually because the larger fish cannot be surrounded in the same way that smaller species can.

Threats & Predators

Because they are so commonly consumed, Atlantic Mackerel’s biggest threats are humans and the fishing industry. However, there are several other threats to consider as well.

Human Threats

The Atlantic Mackerel is important to the Atlantic fishing trade, and humans eat them fresh, smoked, salted, and canned.

About 1-1.5 million tons of Mackerel are caught every year, mostly in trammel nets and trolling lines.

The United Kingdom and Norway bring in the most Atlantic Mackerel each year and globally export it.

Climate Change & Global Warming

Because Atlantic Mackerel are migrating fish, their lives change as the planet warms. Apart from the general environmental impact that commercial fishing has, these Mackerel have begun migrating further north as the water temperature increases, which has exacerbated fishing disputes.

Predators

Atlantic Mackerel have many predators because they are widespread and swim in shallow and deep water.

They are a consistent food source for whales, dolphins, tuna, seals, and sharks. When they swim closer to the surface in the warmer months, they are also frequently hunted by pelicans and other sea birds.

Other Threats

As well as commercial fishing, the Atlantic Mackerel faces threats from recreational fishers. Although they are fast and agile, they are relatively easy to catch on a line because they move in such large groups.

Atlantic Mackerel are also attracted to shiny objects, which means even simple bait will lure them in. 

Conservation Status

Despite extensive fishing and their numerous predators, there are still plenty of Atlantic Mackerel in the sea.

Because they breed so frequently and in such large numbers, they are still considered of ‘least concern’ by the IUCN Red List.

However, industrial fishing is always a concern for both the environment and animal species, so those who eat Mackerel should buy only from sustainable fisheries. This will help to reduce the overall environmental impact in the long term.

Fun Facts About Atlantic Mackerel

  • Atlantic Mackerels are the fastest swimmers in UK waters, able to swim 50 meters in 10 seconds. That’s twice as fast as Michael Phelps!
  • The phrase “Holy Mackerel” has been used for at least 200 years, and began as a reference to Catholics eating fish on Fridays.
  • Atlantic Mackerel swim in schools so large they can stretch for over 20 miles, and their scales create a ripple effect.
  • Other species of Mackerel such as the King and Spanish species are high in mercury and therefore dangerous to eat. However, the Atlantic Mackerel is low in mercury, which is why it’s so popular among fisheries.

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