BFT_SYMP/021 THE BLUEFIN TUNA (Thunnus thynnus) FISHERY IN THE BAY OF BISCAY.

Curricán (troll line) and chapa (silver plated spoon) were the gears used in the Bay of Biscay bluefin tuna fishery up until the middle of the twentieth century, when the first experiments with baitboat were made. The introduction of this new fishing system was a very important development in the region. The fishery is mainly made up of juveniles (<30 kg), but there was a constant presence of adults (group 5+) on the trophic migration towards northern European waters in the past. From observations on board fishing vessels at the beginning of the seventies, the importance in this fishery of age 5+ fish groups is confirmed; but since then this group has practically disappeared from the fishery. The current length composition reveals the absolute dominance of juveniles