Overfishing occurs when the sustainability of fish stocks are threatened by fishing pressure. Thus fisheries managers must ensure that harvesting of stocks takes place at a level that enables the fish populations to replenish themselves.
In EU fisheries, the total allowable catch (TAC) for stocks is set by the Council of Ministers. However, in recent years the Council has agreed on TACs on average 46 percent above scientific recommendations, in spite of 72 percent of all assessed EU fish stocks being estimated as overexploited, with over 20 percent being fished beyond safe biological limits.
In the long-run, the consequences of overfishing are stark. Stock collapse and ecosystem shifts follow on from unchecked fishing pressure and management failure. The 1992 Atlantic cod stock collapse off the coast of Newfoundland is the most noted example of overfishing causing a crash in a fishery. Research has showed that one in four Western fisheries has collapsed in the past 50 years. A damning indictment of how endemic overfishing is. Meanwhile, the reduction of fishing opportunities as a result of overfishing adds further economic pressure to an already stressed fishing sector.
In order to stabilise the depletion of marine wildlife, the EU has signed up to international agreements to reduce overfishing by 2015. The 2002 Johannesburg Declaration committed the EU to rebuilding fish stocks to the point at which they can be harvested in accordance with the Maximum Sustainable Yield (MSY). However, it is highly unlikely this target will be achieved in large part due to scientific advice for quotas not being adhered to, and the issue of fleet overcapacity not being addressed.