The calm waters along Western Australia’s coast are home to some of the world’s most fascinating marine grazers — dugongs and sea turtles. These gentle herbivores play an essential role in keeping reef and seagrass ecosystems healthy.
Dugongs, often called sea cows, drift slowly through shallow bays, feeding on underwater meadows much like land mammals graze in open fields. Alongside them, green turtles browse the same areas, creating one of nature’s most harmonious partnerships.
Their feeding habits, migrations, and survival are vital to maintaining the balance of reef systems such as Montgomery Reef, Ningaloo Reef, and Rowley Shoals — three jewels of Western Australia’s ocean life.
What Are Dugongs?
Dugongs are large marine mammals belonging to the order Sirenia, the same group as manatees. Unlike whales or dolphins, they are herbivores that rely entirely on seagrass beds for food.
Dugongs are streamlined with paddle-like forelimbs, a thick layer of blubber, and a fluked tail that resembles that of a dolphin. Adult dugongs can reach lengths of over three meters and weigh up to 400 kilograms.
While they share a close resemblance to manatees, the two species differ in several ways. The dugong’s tail is fluked, its snout is more downturned for grazing on the seafloor, and it prefers saltwater habitats across the Indian and Pacific Oceans.
The question “Are dugongs and manatees the same?” often arises, but the answer lies in their evolutionary path — they share an ancestor yet have adapted to different environments.
Where Do Dugongs Live?
If you have wondered where dugongs live, their range stretches across 40 countries, but Australia is their greatest stronghold. More than half of the global population resides in Australian waters. The most stable populations are found along the Kimberley coast, Shark Bay, Exmouth Gulf, and the reefs of Western Australia.
Dugongs prefer calm, shallow, and warm waters where seagrass meadows grow abundantly. These meadows serve as both a food source and a shelter. Visitors exploring Montgomery Reef or Ningaloo Reef often spot dugongs feeding near the surface, sometimes alongside turtles. Their presence is an indicator of a healthy marine ecosystem — one where seagrass beds remain intact and water quality stays high.
What Do Dugongs Eat?
The diet of a dugong is simple but crucial to its survival. When people ask “what do dugongs eat?” or “what is a dugong’s diet,” the answer is always seagrass. They feed on species such as Halophila and Halodule, clipping seagrass with their bristled, sensitive upper lips.
As they graze, they leave long feeding trails on the sea floor, which researchers can trace to monitor movement and population size.
These ocean grazers act as natural lawnmowers for the sea. By cropping seagrass, dugongs prevent overgrowth and encourage new shoots to sprout, promoting oxygen circulation in the sediment.
Turtles share some of these feeding zones, although they consume a wider range of food, including algae and jellyfish. Together, dugongs and turtles maintain the delicate balance between plant life and animal life in the reef environment.
Dugongs vs Manatees – How Are They Different?
The comparison of dugongs vs manatees often centers on body structure and habitat. Dugongs inhabit saltwater coastal regions in the Indo-Pacific, while manatees live in freshwater or brackish rivers of the Atlantic.
Dugongs have split, dolphin-like tails, whereas manatees possess broad, paddle-shaped tails.
They are distant cousins in evolutionary terms. Studies show that both species are more closely related to elephants than to whales or dolphins.
Their closest living relatives share similar traits: slow metabolism, sparse body hair, and a need for warm environments. Despite their differences, both dugongs and manatees face the same threats — habitat loss, vessel collisions, and declining water quality.
How Many Dugongs Are Left in the World?
Globally, the dugong population is estimated to be between 80,000 and 100,000 individuals, with Australia supporting around 85,000 of them. In Western Australia, dugongs thrive in places like Shark Bay and the Kimberley coast, where seagrass meadows are protected.
When people ask “how many dugongs are left in the world,” the figure hides an alarming truth — their numbers are decreasing in many regions outside Australia.
Populations in East Africa, the Red Sea, and parts of Southeast Asia have declined sharply due to overfishing and pollution. Australia’s protected marine parks have become one of the last safe refuges for this ancient species.
Why Are Dugongs Endangered?
The main reasons why dugongs are endangered are habitat destruction, boat strikes, fishing nets, and seagrass decline caused by pollution and coastal development. Dugongs are listed as “Vulnerable to Extinction” under the International Union for Conservation of Nature (IUCN).
Their survival depends on seagrass, which is highly sensitive to temperature changes and sedimentation. Cyclones, floods, and marine heatwaves can wipe out entire meadows.
Human activities such as dredging and port expansion have accelerated this loss. Predators of dugongs include sharks, crocodiles, and orcas, but the greatest threat still comes from humans.
Australia has responded with national conservation measures, designating marine sanctuaries and restricting gillnet fishing in areas frequented by dugongs.
These steps mirror the protection efforts seen around Rowley Shoals, where reef ecosystems are managed with similar care.
What Eats Dugongs in the Wild?
Curious minds often ask, “What eats dugongs?” While adult dugongs have few natural predators due to their size, calves are more vulnerable. Large tiger sharks, saltwater crocodiles, and killer whales occasionally prey on them in coastal shallows.
However, most dugong deaths are caused by human activity — particularly fishing gear entanglement and high-speed boats in shallow feeding zones.
In a balanced ecosystem, predators help maintain population health by targeting the weak or sick, but human interference disrupts this balance, leading to a faster decline in numbers.
Can Dugongs and Manatees Mate?
The question “can dugongs and manatees mate?” comes up often because of their close resemblance, but it’s biologically impossible.
Dugongs and manatees belong to different genera, separated by millions of years of evolution. Their reproductive anatomy, behavior, and habitat needs differ entirely.
They do, however, share similar parental instincts — both species give birth to a single calf after a long gestation period, and mothers nurse their young for over a year. This slow reproduction rate is one of the main reasons both dugongs and manatees struggle to recover from population loss.
Are Dugongs Extinct?
No, dugongs are not extinct. But localized extinctions have occurred in areas such as Mauritius and Taiwan, where habitat loss became irreversible. Australia remains its last global stronghold. When people ask, “Are dugongs extinct?” the answer underscores the urgency of conservation.
Their survival in Western Australia depends on the ongoing protection of seagrass habitats and responsible tourism. By following eco-guidelines — maintaining distance, avoiding fast boats in shallow zones, and reducing pollution — visitors can help ensure these marine mammals continue to thrive.
Dugongs and Turtles – Partners in the Ecosystem
Dugongs and turtles share more than feeding grounds. Both species are vital to the health of coral reef ecosystems.
Dugongs graze seagrass beds, while turtles prune algae and clean coral surfaces, preventing suffocation of reef structures. Their movement redistributes nutrients, making the marine environment richer for fish, crustaceans, and smaller invertebrates.
Their cooperation embodies ecological balance. In the shallows near Ningaloo or Montgomery Reef, turtles can often be seen surfacing alongside dugongs. Each performs a role in the cycle of reef renewal — one that’s been in motion for thousands of years.
To learn how to observe such wildlife responsibly, readers can explore our Ecotourism Guides.
Conservation and Research in Western Australia
Conservation efforts in Western Australia are led by the Department of Biodiversity, Conservation and Attractions (DBCA) and supported by Indigenous ranger groups who blend traditional knowledge with modern research.
Tagging programs, drone surveys, and satellite tracking provide insights into migration and breeding behavior. These studies have revealed that dugongs travel hundreds of kilometers in search of seagrass, often crossing entire reef systems. The data helps shape marine park boundaries and speed limit zones in high-traffic areas.
For more on responsible marine wildlife encounters, visit Western Australia Tourism – Marine Wildlife.
FAQs
What are dugongs, and what do they eat?
Dugongs are herbivorous marine mammals that feed primarily on seagrass. They graze along the seafloor, clipping grass with their bristled snouts and leaving visible feeding trails.
Where do dugongs live?
They live in shallow, warm coastal waters across the Indian and Pacific Oceans. The largest populations are found in northern and western Australia.
Are dugongs and manatees the same?
No. They are closely related but differ in tail shape and habitat. Dugongs live in saltwater regions, while manatees inhabit freshwater and estuarine environments.
How many dugongs are left in the world?
Around 80,000 to 100,000 remain globally, with Australia hosting most of the population. Numbers are declining in other regions due to habitat loss.
Why are dugongs endangered?
They are threatened by seagrass loss, boat collisions, entanglement in fishing nets, and climate-related events that damage their habitat.
Conclusion
Dugongs and turtles of Western Australia are more than marine animals — they are indicators of ecosystem health. Their peaceful grazing keeps seagrass meadows vibrant and reef systems alive. Protecting them means protecting the balance of the ocean itself.
From Montgomery Reef to Rowley Shoals, these gentle creatures remind us that the sea’s greatest strength lies not in its power, but in its quiet persistence.
