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Effects accompanying the passage of various dischargesthrough Edfina Barrages

            Emam A. Osman, Ahmed. M. Elfarouk, Mohamed. S. Abdelmoaty

and Yaser M. Ali

 Channel Maintenance Research Institute, National Water Research Center,

Delta Barrage, P.O.Box 13621, Egypt.

ABSTRACT

The importance of fish production increased recently to fill the gap between the demand and supply of protein and to reduce the prices of meat and poultry. Applying Aquaculture in addition to natural fishing becomes the only way to increase the productivity of fish and reduce the gap of fish food production which estimated by 220 thousand tons annually. The aquaculture share is more than half of the total fish production. Using fish cages inside watercourses becomes nowadays a common aquaculture method. This method is widely used nearby Edfina Barrages. In September 2007, remarkable quantities of fish were dead on the region downstream Edfina Barrages with undefined reason. To identify the reasons of this problem, the technical staff of Channel Maintenance Research Institute (CMRI) carried out an intensive hydraulic and laboratory measurements at the study area to show the resulting change in physicochemical and morphological characteristics and reasons of death of fish due to varied water discharges, Barrages management, and accumulation of fish cages, weed growth and algae.

Appropriate solutions were  suggested to maintain and improve fish production and ensure positive social and economic effects.

Key words: Edfina Barrages, , fish cage, morphological changes, physicochemical changes.