Biological characteristics of mackerel

Distribution and stocks: Mackerel are found from Iceland to the Mediterranean, as well as off the coasts of Canada and North America. Although uncertainty remains regarding their independence, two groups are generally distinguished: the western group (distributed from the Bay of Biscay to the north of Ireland) and the North Sea group (from the Strait of Dover to the north of Norway).

Reproduction: The spawning season extends from May to August in the North Sea and from March to July for the western group. Egg production in the Eastern English Channel is estimated at less than 3% of the total production of the western stock.

Migrations and environment: Mackerel is a migratory species for which water temperature plays a decisive role: it likely does not frequent waters below 8.5 °C, and its migrations only begin once this threshold is exceeded. In the 1970s, environmental changes, particularly regarding water temperature, led a large part of the western stock to overwinter in the Western English Channel.

Fishing and assessment: Due to the difficulty in catching individuals smaller than 15 cm, the distribution of mackerel at the post-larval stage is poorly understood. Scientific assessments of this species incorporate the three components of the Northeast Atlantic stock, which leads to this stock being considered overexploited.