fisheriesa general term used to denote all the activities concerned with the catching of fish commercially, whether by long-lining, net, or other means. Until about 1900, commercial fishing was largely unregulated. However, the introduction of modern fishing boats fitted with refrigeration—which allows the boats to remain longer over fishing grounds—and electronic aids such as sonar, meant that regulations on an international scale have had to be introduced. International efforts to try and curb overfishing, and to clamp down on those doing it illegally, are one of the environmental issues facing mankind today.
The carbon dating of fish bones in kitchen middens has shown that humankind has been catching marine fish for tens of thousands of years. In the 19th century a committee of investigation chaired by T. H. Huxley (1825–95) concluded that the oceans offer an inexhaustible resource of fish, and this attitude prevailed for decades afterwards. According to the United Nations’ Food and Agriculture Organization, in 2000 worldwide marine fisheries landed a little under 100 million tonnes of fish, providing 15% of animal protein, amounting to 13 kilograms (28 lb) per capita. However, this figure underestimates the fish that were killed, because at least 20% more were discarded as trash fish and by-catch.
Trawls dragged along the seabed leave a trail of destruction. It is estimated that over half the area of the North Sea is trawled over each year, some parts as frequently as ten times. Globally, over 50% of fish stocks are either overfished or fished to their maximum sustainable capacity, so fishery scientists are desperately seeking to establish how the catches can be maintained while still enabling fishermen to make a living. Marine fishing and aquaculture gives employment to about 20 million people worldwide, and has an annual value of $55 billion. The scales of various fisheries range from individual artisanal fishermen using simple basic equipment catching fish for their own consumption, to large technically sophisticated fishing boats that are fishing to sell their catch for profit.