Diversifying fishing effort in Sicilian fisheries: the case of Fish Aggregating Devices (FADs).

In the Sicilian fisheries, the swordfish (Xiphias gladius, Linnaeus 1758), caught from March to December with several gears which vary according to season, represents one of the most important economic resources. The size composition changes depending on the gear used, the way it is operated, the fishing area and season. The gears used for swordfish fishing (long-lines "for swordfish", drift-nets, harpoons as operated by typical boats named "feluche") mainly catch adult specimens. From August to December, a high number of very young swordfish specimens (1.5 to 4.5 kg) is also caught as by-catch during the albacore (Thunnus alalunga, Bonnaterre 1788) fishing which is carried out by a special long line and hooks only 3 cm long. It was observed that in the same season, fishing areas and with boats of similar type, the fishing of dolphin-fish (Coryphaena hippurus, Linnaeus 1758), using Fish Aggregating Devices (FADs) and purse seine, is hardly practised in spite of the resource availability swordfish. With the present work, which can be regarded as an initial approach to the problem of diversifying and managing fishing effort of swordfish, albacore and dolphin-fish, their fisheries are examined and discussed, not overlooking the economic aspect, by considering weather a reallocation of fishing effort among the previously said resources might avert the risk of swordfish stock depletion.