Some Ecological Effects of Agricultural Drain canals Water on Aquatic Environment

Abstract

The present study was carr-ied out in Sharkia Governorate to study the effect of pumping agriculture drainage water up to natural surface water on different physico-chemical parameters of natural water, and to what extent this mixed water become suitable for using in both agriculture and aquaculture purposes. The study aims also, to follow up the concentrations of some heavy metals and their accumulation in soil samples, Eichhornia crassipes samples as an aquatic plant and in gill, liver and muscle samples of the fresh water fish Oreochromis niloticus . Samples were taken from different sites along El­ wady irrigation canal, which receives agricultural drainage water from Belad El-Aied drain. There were three ditJerent groups of samples, the tirst were taken from El-Wady canal before the point of mixing. Samples of the second group were taken from Belad EI-Aied drain while the third group of samples were taken from El-Wady irrigation canal beyond the point where mixing occurs. With respect to water quality parameters, most of these parameters were shown to be affected with the mixing operation and start to return again to their normal values by moving apnrt from the mixing point. Heavy metal accumulation in different samples was atlected also by mixing practice; where, their concentrations increased significantly in samples collected from the mixed water But the concentrations of most heavy metals, during this study, in water and muscle samples of Oreochromis niloticus, were lower than the maximum permissible limit.