Population Characteristics of the Atlantic Chub Mackerel (Scomber colias Gmelin, 1789) in the Northwestern Atlantic Coast of Morocco

The Atlantic chub mackerel (Scomber colias)is a pelagic fish species which strongly supports fisheries along the Moroccan Atlantic coasts. However, despite commercial landings which have increased over the last decades in Morocco, biological information on this species remain scarce at the national scale. The present study was therefore conducted to examine the reproductive biology of S. colias in the Atlantic coasts of Morocco. A total of 432 specimens were collected from Safi fishing harbor between March 2023 and February 2024, including 207 females and 225 males. The results showed that gonadosomatic index peaked during the colder months, while the spawning season occurred between December and March. Maximum hepatosomatic index values were recorded in June, at 1.13 ± 0.41 for females and 1.33 ± 1.32 for males. The overall body condition factor ranged from 0.71 to 0.91 in both sexes. Finally, size at first maturity was estimated at 18.26cm for males and 19.31cm for females. These preliminary findings provide crucial baseline data that may inform sustainable management practices and support conservation efforts of the Atlantic chub mackerel populations in the Moroccan marine waters.