Limnological studies on lakes and fish farms in Wadi El-Raiyan area, Western desert, Egypt [electronic resource].

Includes reference.

The present study was carried out to evaluate the physical and chemical characteristics of water at three sites (the upper and lower lake as well as fish farms) in Wadi EI-Raiyan area and their effect on fish production. Concentrations of metals (iron, zinc, manganese, copper, cadmitlm, and lead) were also determined in some organs of tilapia species to detect the degree of pollution in this area. Water and fish samples were collected monthly during the spring season of the year 2005. Electric conductivity, total dissolved solids, transparency. total hardness, calcium hardness and chloride showed marked vanations at the three sites. No oxygen depletions were observed in the three sites and it lies in the safe range fflr aquatic organisms. In water, the levels of Fe (in fish farms), Cu (in upper lake and fish farms) and pb (In upper and lower lake) exceeded the maximum world permissible limits. Gills and liver tissues had higher tendency toaccumulate metals more than muscles. Metal concentrations in the edible part of the examined fish were ;n the safety permissible levels for human consumption.

Summary in arabic.

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