Commercial fishing is a worldwide water fish, shellfish, and marine mammals, and their processing 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 processing huge quantities of fish. These large catches are made at heavy expense, however, not only in the cost of the equipment and fuel, but also in the potential depletion of fishery resources.
The major portion of the total fish harvest consists of relatively few fish species, which is divided into two groups. Pelagic species, those which inhabit the near surface layers of the oceans, include several species of herring, tuna, salmon, anchovies, pilchard, sardines, menchaden, and mackerel. Demersal species, fish that inhabit the near bottom layers of the ocean, include cod, sole, halibut, haddock, hake, and flounder. Large catches are also made of animals called shellfish, shrimp, lobster, scallops, oysters, clams, crabs, mussels, and squid. The major marine mammal, the whale, has lost most of its former commercial importance.
Almost all large pelagic and damersal fich catches are made over the continental shelf, the underwater plateau surrounding the continents and large islands. In these water temperatures, water depths, and the currents that influence the quantities of available food create an environment that is highly favorable to the existence of large school of fish. The animals living in and on the bottom of the continental shelf serve as additional food sources for demersal fish. Furthermore, most species spawn on continental shelves, and the main nursery grounds of many species are also in coastal regions.
The Development of the Fishing Industry
Prehistoric people were hunters and food collectors, and they found much of food in lakes, river, and shallow coastal ocean waters. Shellfish were the most accessible food fish, and the large shell heaps found throughout the world bear witness to the first fishing technique, the use of bare hands.
During the Mesolithic Period (c 10,000 – 6000 ac) certain cultures that depended almost entirely on a diet of fish developed primitive fishing technologies, including stone pointed fishing spears, fishing lines and nets, and bone harpoons. Improved equipment increased the size of catches. Drying, salting, and other techniques preserved the catch.
As large fishing craft were built, vessels ventured farther into the oceans, and sea fishing developed into a well defined vocation. Early ocean fisheries were confined to the coastal regions of settled areas and to the Mediterranean Sea. Gradually the rich fishing regions of the Atlantic Ocean and North and Baltic seas began to be exploited.
The opening of the fishing areas around Nova Scotia and Newfoundland had a considerable 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 principal source of New World wealth for England.
The Principal Fisheries
The most important world fisheries are located in waters less than 400 m (1300 ft) in depth. The 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, particularly the Bering Sea, the Gulf of Alaska, and the coastal areas around Japan, and in the Pacific waters off the coasts of China and Malaysia. Other important fishing grounds are found off the Peruvian coast and off the coast of the southeastern United States.
Fishing is often restricted to the spawning periods of a particular species. Fortunately, different stocks of the same species often have different spawning times on different grounds, and this fact enables the fishery to be extended over longer periods. For example, the Norwegian “spring herring” gathers for spawning mainly in September to December.
The local fisheries of the African coast, and many of those found elsewhere in the tropics, remain relatively underdeveloped. The principal limiting factors are first, the narrowness of the continental shelf, which limits the presence of demersal fish, and the existence of a straight coasting that offers few possibilities for good harbors; second, the high temperatures, which effect the keeping quality of the fish catch and third, limited access to the interior, making marketing difficulties.
Major Fishing Countries
By the early 1990s, China had emerged as the nation with the largest fish catches, totaling some 15 million metric tons (16.5 million US tons) in 1992. (The Chinese catch is, however, largely from aquaculture, Japan is second, followed by Peru, Chile, Russia, and United States. The Pacific countries of Indonesia, Thailand, and South Korea complete the list of the ten principal fishing nations.
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