Dugongs are the only member of the order Sirenia from the family Dugondidae. They are found in the Western Indian Ocean with a marginal occurence on the east coast of Southern Africa. In Mozambican waters dugongs are found between the river Rovuma to south of Moma in Nampula province and from the Save river to Maputo Bay. The Bazaruto Archipelago and Mozambique coast is one of the most important african habitats for dugongs in Western Indian Ocean.
Their distribution is limited by specific habitats requirements, particularly sea grass meadows growing in shallow, sheltered lagoons protected by reefs and islands.
Dugongs are one of the most endangered large mammals of the African continent and are amongst the most threatened mammalian species in the western Indian Ocean.
The major causes of their decline are hunting and accidental entanglement in fishing nets, particularly gill nets. Extrapolation of a recent survey produced an estimated total population of just 104 animals remaining in the area surrounding the Bazaruto Archipelago.