Throughout the twentieth century, human activities such as mining, chemical industries, and agriculture have yielded high
accumulations of toxic metals in the environment. These metals, bioavailable and persistent (33), constitute a major environmental problem, adversely affecting ecosystems and public health (24).
Mercury pollution is of real concern because of the high toxicity of the metal and its translocation all along the food chain: mercury is accumulated upward through the aquatic food chain and is transformed to more-toxic organic mercury forms, mainly highly neurotoxic methylmercury