14. Plankton and Common Reed- A Potential Resource for Domestic Animals and Fish in Northern Delta Lakes of Egypt

A concurrent study was conducted during 2005–2009 to evaluate the utilization of the natural resources available in Lake Manzalah, Dakahliah Governorate. The study was designed to rear silver carp (Hypophthalmichthys molitrix) fingerlings in cages alternatively with breading calves (males and females) on plankton and common reed (Phragmites australis) respectively. For intensive culture of H. molitrix fingerlings were stocked at a rate of 10 fish m⁻³, and growing calves with a rate of 30 calves (2:1 cow: buffalo) with an initial average body weight of (10 g/fish, 155 kg/animal) respectively. The results showed that average body weight for fish reached 1,250 g/fish and each cage produced about 3 metric tons. However, as for the calves the weight increased with an average daily gain of 0.44 kg day⁻¹. By the end of the 4th year, the annual production reached for fish to 14,700 tons and for calves 53.6 tons of live body weights. The percentage of the annual profitability reached 387 and 88 % for fish and calves, respectively. Thus, the present study indicates that the maximum production capacity reaching within 5 years could produce 34,000 and 808 tons of fish and calves, respectively. The finding of the present study, if applied to the other eutrophic Northern Delta lakes such as Burullus, Edku, and Maruit, this can certainly help ensuring the production of low cost animal protein for human consumption, creating new jobs in the rural areas around these lakes.