Lagos which is known for its rapid growth in population and industrial development, has become a hub of industrial, agricultural and domestic wastes. According to WHO and Africa UN Environment, Lagos Lagoon is the most polluted African ecosystem with its major wastes coming from oil and textile industry as well as urban sewage carried by the Ogun and Osun rivers. Excessive fishing activities, sand mining and dredging, also contribute to the degradation of the Lagoon's ecosystem. In a study conducted, it was found that these wastes disposed in the lagoon are a threat to fish and mammal biology, which can in turn be harmful to humans. They contain heavy metals such as mercury and cadmium, organic compounds PCBs, Phenolsa, PAHs and organotins. Gallery Notes Lagoons of Lagos Geography of Lagos Lagoons of Yorubaland