Bioeconomic assessment of aquaculture systems in Egypt.

Abstract

Successful improvement of aquaculture in developing countries depends on critical bioeconomic and biotechnical evaluations of conventional systems and high technology transfer methods. This study investigates and compares the relative biological efficiencies and economic feasibilities of a range of different aquaculture systems in Egypt. Relations among economic and biological variables were analyzed for a sample of farms in and around the Nile Delta. Data were collected with interviews, from government records, and from relevant literature. Farms were classified by investment type, culture level, size, and location. Relations between total costs and returns were projected by net profit to gross revenue ratios. Relations among stocking rate, supplemental feed, organic and inorganic fertilizer, and production were analyzed using regression methods. A bioenergetic model was developed to further investigate these relations, to indicate the relative importance of production variables, and to identify critical research needs. Private farms were more economically feasible and biologically efficient than government farms. The most efficient levels of culture in utilizing nutrients were extensive culture with a modified physical environment, and integrated culture with ducks. Farm sizes of 4 to 19 hectares were economically and biologically more efficient than either smaller or larger farms. Location did not have a significant effect on either the profitability of the farms, or on the relations between inputs and production. Supplemental feed was the most important input variable affecting both fish growth and production. Although organic fertilizer had the least effect on production, it had the highest correlation with stocking rate, and it was associated with a higher annual mortality rate. The bioenergetic model showed an inverse relation between stocking rate and an environmental coefficient representing variation in environmental factors. Evaluation of aquaculture systems with various analytical procedures and models provides a strong base for management planning and for aquaculture development decisions.