Heavy metals pollution and their effects on gills and liver of the Nile catfish Clarias gariepinus inhabiting El-Rahawy drain, Egypt.

Abstract

3 Abstract: The water quality and heavy metals (Cu, Fe, Pb, Cd, Mn and Zn) concentrations in the water of El-Rahawy drain and River Nile at El- Kanater El-Khyria (as a reference site for comparison) were seasonally estimated. In addition to that, samples of Clarias gariepinus fish were collected from the two sites to assess the effects of the water quality and heavy metals concentrations in El-Rahawy drain on the fish liver enzymes and some biochemical parameters. Also, the histological alterations of the gills and liver of the studied fish species were studied. The obtained results showed poor water quality in El-Rahawy drain region compared with those obtained from River Nile at El- Kanater El-Khyria. Also, it was found that the heavy metals concentrations in water from El-Rahawy drain region were higher than those obtained from River Nile. Increase in glutamate-oxaloacetate transaminase (GOT) and glutamate- pyruvate transaminase (GPT) activities and different biochemical parameters of C. gariepinus living in El-Rahawy drain were noticed. Also, histological study cleared that gills and liver of C. gariepinus living in El-Rahawy drain suffered from several pathological alterations. All these findings were discussed and referred to the input of agricultural, industrial and sewage water into El-Rahawy drain. It could be recommended that treatment of wastewater including sewage and domestic wastes before discharging into water bodies is a necessary process to protect the fish and the public health from the danger of pollution.