overfishing

Fishing at rates that exceed the sustained-yield cropping of fish species, resulting in a net population decline. For example, in the North Atlantic, herring has been fished to the verge of extinction, and the cod and haddock populations are severely depleted. In the developing world, use of huge factory ships, often by fisheries from industrialized countries, has depleted stocks for local people who cannot obtain protein in any other way. In their 2003 Global Environment Outlook Year Book, the United Nations Environment Program (UNEP) estimated that close to 75% of the world's fish stocks were already overexploited. See also fishing and fisheries.

Environmentalists have long been concerned at the wider implications of overfishing, in particular the devastation wrought on oceanic food chains. The United Nations Food and Agriculture Organization estimates that worldwide overfishing has damaged oceanic ecosystems to such an extent that their ability to support increased fish numbers is significantly reduced. With better management of fishing programmes the fishing catch could in principle be increased; however, it is estimated that, annually, tens of millions of tonnes of fish are discarded from fishing vessels at sea, because they are not the species sought.