Exploitation patterns of Octopus vulgaris in two Mediterranean areas

Exploitation patterns of the common octopus, Octopus vulgaris, in two Mediterranean areas were studied in three ports, two in the Thracian Sea (Greece, Eastern Mediterranean) and one in the Catalan Sea (Spain, Western Mediterranean). The study period of one year (July 1998-June 1999) included a monthly collection of data on commercial landings, fishing effort and length distribution of O. vulgaris. Many gears exploit this species in both areas. Specialised and highly productive artisanal gears (fyke nets, pots and traps) have been developed. Herein it is shown that: (1) trawls are responsible for most octopus landings; (2) trawls exploit mostly the small and immature individuals while the artisanal fleets exploit the large and mature ones; (3) there is a marked seasonality of catches; (4) there is little or no interaction between the gears fishing octopus, indicating that each gear affects a certain size range; (5) and the octopus specimens from the Greek area are clearly smaller than the ones from the Spanish area. Our results suggest that octopus fisheries require more effective management strategies. The creation of marine harvest refuges may be beneficial.