Seasonal variations of heavy metals concentrations in mullet, Mugil cephalus and Liza ramada (Mugilidae) from Lake Manzala , Egypt

Abstract

easonal variations in the concentrations of four heavy metals; zinc (Zn), copper (Cu), lead (Pb) and cadmium (Cd), were determined in gills, skin and muscles of two fish species (Mugil cephalus and Liza ramada) from five locations in Lake Manzala . The average concentrations of the metals in fish tissues exhibited the following order: Zn>Cu>Pb>Cd. The statistical analysis revealed a significant effect of seasons, locations and fish tissues for all metals measured. The highest values of the metals were recorded in hot seasons (summer and spring). Fish samples from location V (Bahr El-Bakar) displayed the highest metal concentrations in their tissues. The highest concentrations of heavy metals were found in gills tissue of both fish species, while the lowest ones were recorded in muscles tissue. The values of the metals detected in the edible fish muscles were within the permissible limits.