Recherches sur la sélectivité des chaluts pour la pêche de la sole, du merlan et du merlu

The International Agreement, concerned with Overfishing, of April 5th, 1946, enforced on April 5th 1954, and regulating the size of the mesh of mobile gear north of L. N, 48° limits, amongst others, the size of the mesh of mobile gear (stretched and wet) north of L. N, to 48° to 80 mm (provisionally 75 mm during the first few enforcement years). However, this measure applies uniformly to a series of commercial species with a different market size defined for each of them by the same agreement. Yet, if the 80 mm mesh works for the catch of species of high market size (cod, haddock, plaice), it is inefficient with species of small market size that swim easily through the mesh (whiting, flounder). As a consequence to this incompatibility between measures imposing a single mesh size and those establishing market sizes, the fishery of some types of fishes could show a shortfall: It seemed important to reflect on a mesh size which would enable the catching of a number of species of commercial importance from their market size, in accordance with what fishermen are allowed to as well as with the protection of species. This is the focus of the experiments described in this work and which were conducted on board fishing vessels and R.V. "Président Théodore Tissier" from 1954 to 1956. These experiments first dealt with whiting and flounder, then with hake.