Commercial fishing is the activity of catching 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. Large-scale commercial fishing is also known as industrial fishing. The commercial activity is aimed at the delivery of fish and other seafood products for human consumption or as input factors in other industrial processes.
A fishing fleet is an aggregate of commercial fishing vessels.
Trawling is the most important and one of the most efficient fishing methods in the world. Today, commercial trawling is carried out from very shallow waters up to a depth of 2000 m.
These vessels use surrounding and seine nets and comprise a large group appearing in all sizes, ranging from open boats, usually at least 10 m in length, to ocean going vessels. Seiners are normally used to catch aggregating pelagic species but there are special applications that target demersal species.
Purse seiners are ideal for catching fish like tuna that aggregate, especially in schools, near the surface. The vessel surrounds the school of tuna with a deep curtain of netting and then the bottom of the net is pursed (closed) underneath the school by hauling a wire which runs from the rings on the bottom of the net and back to the purse seiner.
These vessels are used for setting pots or traps for catching fish, lobsters, crabs, crayfish and other similar species. Trap setters range from open boats operating inshore up to larger decked vessels of 20-50 m operating to the edge of a continental shelf.
A factory ship, also known as a fish processing vessel, is a large ocean-going vessel with extensive on-board facilities for processing and freezing caught fish or whales.
Contemporary factory ships are automated and enlarged versions of the earlier whalers and their use for fishing has grown dramatically. Some factory ships also function as mother ships.