Fishes are an economical and healthy source of protein for the majority of the world community. However the concentration of mercury in fish due to anthropogenic emissions pose health risks to humans. The concentration of organic mercury (methylmercury) dominates 80-90 persen total mercury concentrations in fish flesh. The Accumulation of mercury increases with the rise of water temperature, organism age, time of exposure, and the concentration of protein- bound mercury. The decline in salinity or hardness, pH, organic matter content, and the presence of Zn, Cd, or Se in solution will also increases the accumulation of mercury. The rate of accumulation of methylmercury in fish affects the toxicity, in which a low rate of accumulation associates with a higher tolerance.