Commercial fishing, also known as industrial fishing, is the activity of capturing fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions.
Commercial fishing methods have become very efficient using large nets and factory ships. Many new restrictions are often integrated with varieties of fishing allocation schemes (such as individual fishing quotas), and international treaties that have sought to limit the fishing effort and, sometimes, capture efficiency.
Fishing methods vary according to the region, the species being fished for, and the technology available to the fishermen. A commercial fishing enterprise may vary from one man with a small boat with hand-casting nets or a few pot traps, to a huge fleet of trawlers processing tons of fish every day.
Commercial fishing gears today are surrounding nets (e.g. purse seine), seine nets (e.g. beach seine), trawls (e.g. bottom trawl), dredges, hooks and lines (e.g. long line and handline), lift nets, gillnets, entangling nets and traps.
There are large and important fisheries worldwide for various species of fish, mollusks and crustaceans. However, a very small number of species support the majority of the world’s fisheries. Some of these species are herring, cod, anchovy, tuna, flounder, mullet, squid, shrimp, salmon, crab, lobster, oyster and scallops. All except these last four provided a worldwide catch of well over a million tonnes in 1999, with herring and sardines together providing a catch of over 22 million metric tons in 1999. Many other species as well are fished in smaller numbers.