Driftnets stand accused of not being sufficiently selective and of trapping unacceptable numbers of cetaceans, marine mammals, birds and reptiles.
Initially, drift nets 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 drift nets 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. Although the nature and volume of non-targeted species, or by-catches (species caught by accident) vary according to the design of the net, the fishery involved and the zones in which the net is used, the larger net meshes and greater sizes of the nets have proved fatal for a large number of species.
In the early 1990s, responding to public concern, the United Nations (UN) passed a resolution asking for a moratorium on the use of large drift nets. The EU Council of Ministers, with the backing of the European Parliament, decided to impose a maximum limit of 2.5km on drift nets used by EU vessels (this measure, like the UN moratorium, did not include the Baltic Sea).
Problems continued, however, because there were still too many instances where the rules on maximum length were not respected. The effective monitoring of the implementation of this rule at sea presents many practical problems. It requires extensive resources and manpower and a level of expenditure difficult to sustain over a long period of time for both the EU and individual Member States. So, despite the regulation, the amount of fishing with drift nets continued to expand. Concerned by the effects of this growing pressure on fish resources and the related increase in the volume of by-catch, the Commission proposed, in 1994, to ban drift nets - ban which could have become effective a few years later - but Member States felt unable to adopt these proposal.
After experiencing some difficulty adjusting to the 2.5km drift nets, the Atlantic tuna vessels managed to increase efficiency and, after a while, this technique became economically very attractive. In June 1998, however, a majority of Member States decided that, all things considered, the time had come to ban the use of drift nets in tuna fisheries.