Fish samples
Three different fish samples Heterotis niloticus, Oreochromis niloticus and Clarias gariepinus were collected from stream. The mean total lengths and total weights of fish were (15.85 cm and 73.28 g) in Heterotis niloticus, (12.40 cm and 49.55 g) in Oreochromis niloticus and (14.33 cm and 58.24 g) in Clarias gariepinus. Fish samples were transported in ice box to the laboratory,where samples of different tissue/organs taken were sorted. Metals in fish tissue/organs were extracted as described by (AOAC, 1990). Atomic Absorption Spectrophotometer (Model Thermo Electron Corporation, S. Series AA Spectrometer with Gravities furnace, UK,) instrument was used to detect the heavy metals. The concentrations of heavy metals were
expressed as mg/l for water and mg/g. dry weight for sediment samples and fish organs.