The protected Mafia Island Marine Park (821km²) is located between the Rufiji River Delta to the west and the open Indian ocean to the east. These two influences form one of the finest complexes of estuarine, mangrove, coral reef, and marine ecosystems in the world. The coral reefs being particularly diverse for Eastern Africa, providing a spectacular habitat for over 400 species of fish and 48 genera of hard coral - a scuba divers paradise! These unique habitats include hard coral dominated reefs, soft coral and algal dominated reefs, sheltered back reef systems, inter-tidal flats with hard and soft substrate, mangrove forests, extensive seagrass beds, algal, sponge and soft coral sub-tidal beds. The area includes critical habitat for the dugong (Dugong dugon) and sea turtles (Chelonia mydas, Eretmochelys imbricata, Lipidochelys livaceae, Dermochelys coriacea and Caretta caretta) as well as whale sharks (Rhincodon typus) and has been recognised as a critical site for biodiversity.