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,
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,
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.