COMMERCIAL FISHING
Commercial fishing is a worldwide enterprise that involves the capture of marine and freshwater fish and shellfish and their preparation for market. Fishing equipment ranges from small boats whose nets are cast and hauled in by hand to factory ships equipped with the most advanced technologies for finding, harvesting, and preparing huge amounts of fish. These large catches are very costly, however, not only in the price of their equipment and fuel, but also in the depletion of fishery resources their use brings about.

The major portion of the total fish harvest consists of few fish species, which are divided into two primary groups. Pelagic species - those which live in the near-surface layers of the oceans, this include several species of herring, tuna, salmon, anchovies, pilchard, sardines, menhaden, and mackerel. Demersal species - fish that live in the near-bottom layers of the ocean, this includes cod, sole, halibut, haddock, hake, and flounder. Large catches are also made of a group of fish classed commercially as SHELLFISH - shrimp, lobster, scallops, oysters, clams, crabs, mussels, and squid. WHALING was once a major part of the fishing industry. Overfishing has endangered many whale numbers, however, and the field has lessened in importance.

Almost all large pelagic and demersal fish catches are made over or near the continental shelf, the underwater plateau around the continents and large islands. In these waters temperatures, water depths, and the currents that influence the amounts of available food create an environment that is highly favourable to the existence of large schools of fish.

The animals living in and on the bottom of the continental shelf serve as additional food sources for demersal fish. Also, most species spawn on continental shelves, and the main nursery grounds of many species are also in coastal regions. The main fishing grounds are located on the wider continental shelves of the mid and high latitudes. The single most important area is the North Pacific, where as much as one-quarter of the world\'s fish catch is taken.

THE DEVELOPMENT OF THE FISHING INDUSTRY

Prehistoric people were hunters and food collectors, and they found much of their food in lakes, rivers, and shallow coastal ocean waters. Shellfish were the most accessible food , and the large shell heaps found around the first fishing technique, the use of bare hands.

During 10,000-6000 BC, certain cultures that depended almost entirely on a diet of fish developed primitive fishing technologies. The Scandinavian Maglemosian culture used stone-pointed fishing spears, antler and bone harpoons and fishhooks, and lines and nets woven of bark fiber. Improved equipment increased the size of catches, and preservation techniques were developed for drying, smoking, salting, and pickling fish. As larger boats were built, fishing craft adventured farther into the oceans, and sea fishing developed into a well-defined business, with settlements whose main occupation was catching fish.

Early ocean fisheries were confined to the coastal regions of settled areas and to the Mediterranean Sea, which had been the traditional fishing grounds for large numbers of fish species, especially tuna. Slowly, the rich fishing regions of the Atlantic Ocean and the North and Baltic seas began to be exploited. The opening of these new fishing grounds had a significant influence on the spread of trade during the Middle Ages and on the establishment of new trade routes - for example, the herring fisheries in the southern Baltic and North seas that helped to establish the HANSEATIC LEAGUE.

The opening of the fishing areas around Nova Scotia and Newfoundland had a serious effect on European history. First fished by the French in the early 1500s, by the beginning of the 17th century the North Atlantic fisheries had become the main source of New World wealth for England.

PRINCIPAL FISHERIES

The most important world fisheries are located in waters less than 400 m in depth. Major fishing grounds are in the North Atlantic including the GRAND BANKS and the Georges Banks off the New England coast, the North Sea, the waters over the continental shelves of Iceland and Norway, and the Barents Sea; in the North Pacific, specifically the Bering Sea, the Gulf of Alaska, and the coastal areas around Japan; and off the coasts of China and Malaysia. Other important fishing grounds are found off the coasts of the southeastern United States, Chile, Peru, Argentina, and the Falkland