EFFECT OF SOME WATER POLLUTANTS ON THE NILE TILAPIA, OREOCHROMISNILOTICUS COLLECTED FROM THE RIVER NILE AND SOME EGYPTIAN LAKES

Abstract

P ollution of surface water has increased due to the industrial effluents, waste municipal and agricultural drainage water that discharge directly into it. The present study measured the concentrations of some heavy metals (Fe, Cu, Zn> Pb and Cd) in water, sediment and Nile tilapia fish collected from certain Egyptian lakes (Maryut, Manzala, El-Burullus, Edku and Qarun), a polluted site of the River Nile (Shubra El-Khiema, Cairo sector), in addition to Ismalia canal (El-Abbassa region). The results revealed that fish collected from the polluted site of the River Nile and the studied lakes (Maryut, Manzala, El-Burullus and Edku) showed the lowest growth factor, hepalosomatic index, meat quality and disturbances in the studied physiological state as indicated by the increase in serum glucose, total protein, AST, ALT, alkaline phosphstase, creatinine, uric acid and a decrease in serum total lipids. In comparison, fish collected from lake Qarun exhibited higher levels of meat quality and growth indices than those collected from the other studied sites and showed normal levels in the different examined biochemical parameters as those of the control group collected from Ismalia canal. Chemical analyses of water samples suggested that high salinity, total alkalinity and total hardness in lake Qarun might have inhibited the bioaccumulation of any of the studied heavy metals