The blue mackerel, or Scomber scombrus, is a highly sought-after saltwater fish by sport fishermen in Quebec, particularly in the Gulf of Saint Lawrence and its surroundings. Known for its speed and schooling behavior, it offers an exciting fight when caught on a line. Although it is not the largest of fish, its fighting spirit and abundance make it a prime target for sea fishing enthusiasts. The blue mackerel is also a migratory fish, moving in large schools, which can make it easy to spot for those who know where to look. As a pelagic species, it plays an important role in the marine ecosystem, serving as prey for many larger predators.

The blue mackerel is easily identifiable thanks to its streamlined body and distinctive black stripes running along its sides. Its overall color varies from blue-green on the back to a silver belly, allowing it to effectively camouflage in its marine environment. It has a relatively small mouth but is well adapted to capture small prey such as zooplankton and small fish. The dorsal fins are well developed, with the first dorsal fin being spiny, followed by a second softer fin. The caudal fin is forked, giving it impressive speed. The scales of the mackerel are small and smooth, contributing to its hydrodynamics. Young individuals closely resemble adults, although they are often slimmer and less colorful. There are no marked differences between males and females, even during spawning.

In Quebec, the blue mackerel is primarily found in the Gulf of Saint Lawrence, particularly around Gaspésie and the Magdalen Islands. It is also sometimes observed in Bas-Saint-Laurent and Côte-Nord. Although it is rarer in inland waters, it is not impossible to encounter it in certain bays and estuaries during seasonal migrations. This species is abundant in coastal waters during the summer, where it forms large schools, making it easier to catch by sport fishermen.

The blue mackerel prefers coastal and pelagic waters, often found at depths ranging from the surface to about 200 meters. It is attracted to underwater structures such as reefs, shipwrecks, and sandbanks, which harbor its favorite prey. The ideal temperature for blue mackerel is between 10 and 14 °C, prompting it to migrate north during the summer. Fishermen should look for mackerel schools in clear, oxygenated waters, often near strong currents where plankton is abundant.

The spawning of blue mackerel occurs in spring, generally between April and June, when water temperatures begin to rise. Females lay thousands of floating eggs that hatch within a few days. The fry, very small, feed on zooplankton and grow rapidly. Within a year, they typically reach a size sufficient to join adult schools. Sexual maturity is reached at about 2 to 3 years of age. The blue mackerel can live up to 6 or 7 years, although most do not exceed 5 years.

Spring → Spawning and laying → Summer → Rapid growth → Fall → Migration south → Winter → Wintering in deeper waters.

The blue mackerel is a schooling fish, moving in large groups, which helps protect it from predators and facilitates food searching. It is not particularly territorial, preferring open waters where it can move freely. The mackerel is sensitive to changes in light and shadow, often attracted to changing lighting conditions. Fishermen should know that the mackerel is more active during cloudy days or early in the morning and late in the afternoon. Windy conditions can scatter schools, making fishing more difficult.

The diet of the blue mackerel varies depending on its age. Fry primarily feed on zooplankton and tiny crustaceans. As they grow, mackerels start to consume small fish such as herrings and sand eels, as well as squids and other marine invertebrates. During spring and summer, their diet is abundant due to the proliferation of plankton and small prey, making them more active and easier to catch. In autumn, their diet adapts to available resources, but they continue to actively hunt to build reserves for winter.

Fishing for blue mackerel is particularly productive during summer, when schools are abundant in the Gulf of Saint Lawrence. The best times for fishing are early in the morning and late in the afternoon, when lighting conditions are favorable. In spring, mackerels begin to approach the coast for spawning, offering good fishing opportunities. Autumn is also a good season, although schools start migrating south. In winter, fishing is more difficult as mackerels are found in deeper and less accessible waters. Weather conditions greatly influence their activity; overcast skies and stable atmospheric pressure are ideal.

To fish for blue mackerel, favor bright and reflective lures in clear waters, such as blue, green, and silver. In murky water, fluorescent colors like pink and yellow are more effective. In sunny weather, shiny metallic lures work well, while in overcast conditions, opt for matte or natural colors. Small-sized lures imitating natural prey like small fish or shrimp are often the most effective.

For fishing blue mackerel, use a rod 6 to 7 feet long, with medium power and fast action to detect subtle bites. A medium-sized spinning reel fitted with a 10 to 15 lb line is ideal to withstand the mackerel's fighting spirit. Size 1 to 1/0 hooks are appropriate, and a 20 lb fluorocarbon leader can help reduce visibility in the water and prevent cuts from sharp teeth.

Handle the mackerel carefully to avoid getting pricked by its dorsal fins. Use a firm yet gentle grip, and avoid keeping it out of the water longer than necessary. For a successful release, support the fish in the water until it regains its strength and swims away on its own. For a photo, keep it close to the water and minimize exposure time to air.

The blue mackerel is prey to many predators, including seals, seabirds such as terns and gannets, as well as larger fish like bluefin tuna and mako sharks. These predators play a crucial role in controlling mackerel populations and maintaining the balance of the marine ecosystem.

In Quebec, blue mackerel is subject to regulations to prevent overfishing, with quotas and well-defined fishing seasons. It is important to respect these rules to ensure population sustainability. Catch-and-release is encouraged, especially for smaller specimens, to preserve stocks for future generations. The mackerel is not currently considered threatened, but careful management is essential to maintain its abundance.