Résumé
The common octopus (Octopus vulgaris) is the main target species of the cephalopod fishery of the Moroccan waters in the south Atlantic. The octopus population is widely distributed throughout the continental shelf between Cap Boujdor (26 degree N) and Cap Blanc (21 degree N) and is made up of two stocks, the Dakhla and Cap Blanc stocks. The life cycle of the octopus is characterized, in this area, by a clear opposition between the recruitment and reproduction phases showing very different spatial patterns. The aim of this work is to describe the spatial pattern of the main phases of the octopus life, using the trawl-scientific surveys carried out by the INRH, twice a year from 1998 to 2003. Through a geostatistic approach, the most important demographic classes of octopus have been analyzed and mapped by kriging, especially the mature females' class to feature the spawning area and the juveniles' class to feature recruitment area. The results indicate that the spawning process occurs over the whole continental shelf and that there is no spawning migration for the Moroccan octopus. This was also reported for the Mauritanian octopus stock, but is contradictory to the Mediterranean case. This has very important implications in terms of resource management as it allows to re-evaluate the impact of the small-scale coastal fishery on the spawning stock biomass. Under the assumption that spawning octopus converge to the coast, these are often suspected to deplete the spawning stock.