IJSRP, Volume 3, Issue 9, September 2013 Edition [ISSN 2250-3153]
Mulu Berhe Desta, Mehari Muuz Weldemariam
Distribution of trace metals (Zn, Cu and Cr) in water; bottom sediment and two fish species (Tilapia zilli and Oreochromis Niloticus) collected from Lake Gudbahri were analyzed using Varian AA240FS Atomic Absorption Spectrophotometry in order to ascertain their suitability for consumption and other domestic uses. Results indicated that Tilapia zilli contained the highest concentration of Zn (84%) of the detected heavy metals, followed by Cu (15%), while Cr (1%) was the lowest value. Similarly, Nile Tilapia contained the highest concentration of Zn (77%), followed by Cu (21%). Bioaccumulation factors of Nile Tilapia were Cu (409), Zn (110), Cr (57) and Tilapia zilli showed 345.5, 112 and 28.6 for Cu, Zn and Cr respectively. The distribution of heavy metals in sediment and water samples were in the order of magnitude as by Zn>Cr>Cu and Zn>Cu>Cr respectively whereas the order of heavy metals concentration in fish samples were found to decrease in sequence as Zn>Cu>Cr. The levels of the heavy metals concentration were compared with permissible limit values provided by WHO, FEPA and various national and international agencies. These levels of heavy metals accumulated in the two fish species might be due to the increase in agricultural influx waters, domestic wastes and some anthropogenic activities.