Dugong

The dugong is a slow-moving, spindle-shaped mammal distinguished by a broad, downturned muzzle and a deeply notched, whale-like tail. Adults commonly reach about 2.5–3 metres in length and can weigh several hundred kilograms. Unlike its close relatives, the manatees, the dugong has a fluked tail suited to open-water swimming, while its forelimbs have become paddle-shaped flippers.

Dugongs breathe air but spend nearly all of their lives at sea. Their nostrils sit near the top of the snout, and dense bones help provide ballast while they feed on the seabed. Adults primarily eat seagrasses, using sensitive, muscular lips to uproot or crop vegetation; their feeding trails can disturb sediment and leave visible furrows in meadows.²

Dugongs occupy warm, shallow coastal waters from East Africa and the Red Sea through the Indian Ocean, Southeast Asia, northern Australia and parts of the western Pacific. Their distribution follows suitable seagrass habitat rather than a single continuous coastline, and many populations are separated by deep water, unsuitable shores or heavy human activity.¹

Females usually give birth to one calf after a gestation of roughly 13 months. The calf remains dependent on milk for an extended period and may stay close to its mother for more than a year. Slow reproduction makes local populations especially vulnerable: even where adults survive, losses from fishing gear, hunting or habitat degradation can take decades to replace.

Dugong survival is closely tied to the condition of seagrass ecosystems. Coastal development, dredging, pollution, boat traffic and destructive fishing can remove or fragment feeding grounds, while floods and marine heatwaves can cause large-scale seagrass loss. Dugongs are also killed by entanglement in nets, vessel strikes and deliberate hunting in some parts of their range.

The species is listed as Vulnerable on the IUCN Red List, although its status differs sharply among regions. Conservation measures include protected seagrass areas, safer fishing practices, restrictions on hunting, dugong surveys and cooperation among range states. The Convention on Migratory Species identifies the dugong as a species requiring international coordination because animals and threats cross national boundaries.¹³

Dugong feeding is not simply destructive grazing: by cropping seagrass, animals can alter plant composition, recycle nutrients and create patches used by other coastal organisms. Their preference for particular seagrass species also means that a meadow may remain visually intact while losing much of its value as dugong habitat.²

The species has unusual dental adaptations. Males commonly develop tusks, and females may also show tusk-like teeth; rear molars are replaced progressively as abrasive sand enters the mouth during feeding. Dugongs have also featured in coastal knowledge systems for centuries, including traditions of Aboriginal Australians and other Indigenous peoples, for whom hunting, stewardship and ceremonial relationships with the animal remain significant in some communities.

Sirenia

The mammalian order containing dugongs, manatees and the extinct Steller's sea cow.

Seagrass meadow

A shallow marine habitat formed by flowering plants adapted to living underwater.

Fluke

A broad, horizontally oriented tail fin used by dugongs and whales for propulsion.

Vulnerable

An IUCN Red List category indicating a high risk of extinction in the wild.