What Divers Should Know About Dugong

The dugong, a unique marine mammal, ranges widely across the Indo-West Pacific, inhabiting warm coastal waters from the western Pacific Ocean to the eastern coast of Africa. This spans an estimated 140,000 kilometers of coastline, primarily within 26° and 27° north and south of the equator. As the only sirenian found throughout its vast distribution, it is largely restricted to coastal habitats that support seagrass meadows. Significant populations concentrate in wide, shallow, protected areas such as bays, mangrove channels, and the waters around large inshore islands. Australia's northern waters, between Shark Bay and Moreton Bay, are considered a contemporary stronghold for the species.

Divers typically encounter dugongs in these seagrass-rich environments. They are generally observed at depths around 10 meters (33 feet). However, in areas with a shallow continental shelf, dugongs may venture over ten kilometers from shore and descend to depths as far as 37 meters (121 feet) to graze on deepwater seagrasses. Their sharply downturned snout is an adaptation for feeding on benthic seagrass communities, making them the only strictly marine herbivorous mammal. These gentle giants, identifiable by their fluked, dolphin-like tail distinguishing them from manatees, can live for 70 years or more, though their slow reproduction makes them particularly vulnerable.