Impact of the water quality of El-Rahawy Drain on some g enetic and histopathological aspects of Oreochromis niloticus

Abstract

The present study aims to evaluate the water quality of two locations in Rosetta Branch of River Nile and its histopathological and genetic adverse effects on Nile tilapia (Oreochromis niloticus). Water and fish samples were collected from up and downstream of El-Rahawy Drain discharge point (location I and II, respectively) during the summer and winter seasons. The water quality, liver histopathology and DNA alteration of fish was examined. ISSR-PCR technique was used to assess the genetic variation of fish samples from these locations. The water quality parameters ( BOD, COD,……)were increased at location II compared with location I in addition to depletion in dissolved oxygen. Moreover, the fish samples collected from location II showed severe histological and molecular alterations than those collected from location I. It is recommended that the government must increase the awareness of people around the River Nile, and improve the environmental management to reduce the risks of polluted water and consuming the fish exposed to this water on human health.