The present study included the effect concentrations of mercury element (0.05-
0.2) mg/l on algae Chlorella vulgaris. The data showed decrease cells number,
growth rate and increase inhibition rate with increasing mercury concentration and
the elongate of exposure period which showed the toxicity of the element. Also the
results showed the toxic effect of mercury at concentrations (0.01-0.05) mg/l on the
animal Simocephalus vetulus, by decreasing the longevity rate, growth rate,
fecundity, fertility, number of brood per female during 21 days compared to the
control.