Seasonal variation of heavy metals accumulation in muscles of the African Catfish Clarias gariepinus and in River Nile water and sediments at Assiut Governorate, Egypt

Abstract

Water pollution is one of the most principal environmental and public health problems in river Nile. Heavy metals concentrations; iron (Fe), copper (Cu), cadmium (Cd), lead (Pb), zinc (Zn), chromium (Cr), manganese (Mn), mercury (Hg) and nickel (Ni) were determined in water, sediment, and fish muscles of Clarias gariepinus collected from six areas at Assiut Governorate on river Nile using inductively coupled plasma mass spectrometry (ICP-MS). The results revealed that Zn, Cu and Fe concentrations were the highest in water and muscles, followed by Mn, Cr, Pb, Cd, Ni and Hg in areas under investigation. Also, summer was the highest accumulation season and winter was the lowest one. In sediments, the order of accumulation was Fe>Zn>Mn>Cu>Ni>Pb>Cd>Cr>Hg. In general, the bioaccumulation factor (BAF) for Cr was the lowest while, the highest was recorded for Ni and Hg followed by Cu in both relation fish/sediment and fish/water. In conclusion, the present study found that the accumulation and bioaccumulation factor of heavy metals especially Zn, Fe and Cu were higher in summer season due to increase of temperature, accordingly the authors advice to decrease fish consuming in summer to avoid the accumulation of heavy metals.