The ban may, in the short term, have a negative economic and social impact on the communities concerned, but no ban would have had even more serious consequences. To help these communities make the transition to safer techniques, the European Union, in co-operation with Member States, will provide measures to ensure that this impact is kept to a minimum. Driftnets are nets that are held on or just below the surface of the water thanks to floats. Their height varies according to the fishery concerned but, in the case of large nets, is generally comprised between 20 to 30 metres. They are weighted at the bottom so that the tension created between the floats and the weights holds the net vertically in the sea.
Nets can drift on their own or, more frequently, with the vessel to which one end is tied.
Driftnets stand accused of not being sufficiently selective and of trapping unacceptable numbers of cetaceans, marine mammals, birds and reptiles. Initially, driftnets were used to catch small species and did not give cause for concern. In the Mediterranean, for example, this technique has long been used to fish a variety of tuna-like species with nets of limited lengths. Problems started when driftnets were modified by enlarging their meshes in order to catch larger species and by increasing their overall sizes to maximise catches. The use of these large nets multiplied first in the Pacific, before being adopted in Atlantic tuna fisheries.