Joal-Fadiouth, located in department of Mbour (region of Thies), 118 kilometers from Dakar, the capital of Senegal, is an area where one can find a large swamp with mangroves whose self-propagating roots serve as growth support for young oysters. The importance of those oysters, both on the domestic and foreign markets and the ever greater threat of pollution of our coasts led us to search for and measure out heavy metals. In fact, it is well know that the accumulation of those elements in the food chain can be at the origin of severe poisoning. It appears, in the light of the results obtained that the level of pollution by heavy metals in this part of the senegalese coast has not yet reached alarming limits.