In Egypt the potentialities of fish culture industry are great. This is due to the presence of the following natural resources: a) the long seashores bordering the north and east coasts of the country, b) the long river Nile crossing the country from the high dam at south to the Mediterranean sea at the north, c) the numerous small branches making a large net of water stream either supplying the lands by irrigated or draining water, and d) some big lakes with brackish water scattered all over the country (Morsy, 1994). The need for rapid development and proper management of the fishery is becoming a necessity in view of the high demand for fish as a relatively cheap source of animal protein. Fish may compensate the present deficiency of other expensive sources. Aquaculture is the science and technology of producing aquatic plants and animals (Lawson, 1995). While aquaculture has been practiced in Egypt for thousands of years, systematic aquacultural research to increase fish pond yields in Egypt is relatively new (Green, 1995). By “aquacultural systems” we mean the commercial production systems of aquatic animals either in controlled or uncontrolled environment (Bala and Satter, 1989). Aquaculture plays an increasing important role in the world fishery production. It has been the world’s fastest growing food production system for the past decade. The world fish production of aquaculture increased about more than three times through the period from 1988, about 7.5 million tons to 22.0 million tons in 2000. This increase is a result of intensification of production from the existing fish farms and the expansion of areas under cultivation (El-Ebiary 2002). Fish culture systems are increasingly intensive, largely due to the shortage of water and land and labor resources. There is also a need in Egypt for quick production of market-size fish to meet the demand of an increasing population (Sadek et al., 1992). Intensification in aquaculture is defined as management in which more fish are produced per area unit, by complementing of substituting the natural food web in culture environments with external inputs such as feeds and fertilizers and by supporting cultured populations with oxygen and biofiltration whenever necessary (Mires, 1995). Intensification is an option which has to be evaluated economically and practically. The degree of intensification is characterized mainly by the density of stocking. The choice of the rate of production depends on the existing business environment, i.e market infrastructure, competitors, and potential prices, as well as the availability of various essential inputs, such as (a) fry and fingerlings, (b)basic farm infrastructure, such as sufficient water supply and roads, (c) specific feed ingredients, (d) energy, usually electricity, (e) professional know-how, and (f) equipments i.e. aerators, transportation facilities, and seine nets. |
