Abstract:
Heavy metal consist less than one percent of living mass organisms and their different density
cause to some disorder, surface waters and also acidic rains can transfer these metal to lake via
washing polluted environment.
Increased anthropogenic activities have increased the potential pollution of the lake especially
the heavy metal pollution which may be toxic to human and aquatic fauna. To determine and
compare heavy metal content (Pb, Cd, As and Hg) in edible tissue and gill of grey mullet. The
result of heavy metal level is several times lower than arsenic and were found in range 0.01-0.02
g w.w. The concentration of heavy metal in water and their accumulation in the edible tissue of
nile Tilapia fish ranged from undectable to 4.57 µg/l for copper (Cu) and also form undectable to
0.25 µg/l ror lead (Pb) but dissolved nickel (Ni) and zinc (Zn) concentration were totally
undictable in water sample in lake Hawassa. The order of heavy metal concentration in fish
sample were found to decrease in sequence as Zn>Cu>Cr. The levels of the heavy metal
concentration were compared with permissible limit value provided by WHO.
