Thailand's largest dugong population grazing seagrass meadows so genetically diverse they're a global conservation priority. 200+ 'sea cows' in one bay.
A marine mammal metropolis
In the Andaman Sea, off the coast of Thailand's Trang Province, is a habitat for the vulnerable dugong (Dugong dugon). The waters around Ko Libong and in Hat Chao Mai National Park have the country's largest population of these marine mammals. This concentration of dugongs is directly linked to the vast and exceptionally diverse seagrass meadows that carpet the seafloor. These meadows are food; their genetic makeup makes them a site of global conservation importance.
The area has up to twelve species of seagrass, making it the most diverse seagrass area in Thailand. Species like Enhalus acoroides and Halophila ovalis are prevalent. This biodiversity supports a resilient ecosystem. A wider gene pool allows the seagrass to better withstand environmental stressors such as disease, pollution, and rising sea temperatures. The unique genetic makeup of the dugong population here is also studied, and research shows that animals in the Andaman Sea are genetically distinct and show high levels of diversity compared to other regions.
An ecosystem under pressure
An adult dugong can eat up to 40 kilograms of seagrass daily, using its snout to graze along the seabed and leaving distinct feeding trails. The health of the Trang seagrass ecosystem directly supports the large local dugong population. However, this balance is threatened. In recent years, significant die-offs of seagrass have occurred, with some feeding grounds experiencing a 50-70% reduction in cover. This loss is from a combination of climate change-related factors, such as unusually low tides that expose the plants to excessive heat, and potential pollution from coastal runoff.
The consequences for the dugongs have been severe. Malnutrition and starvation are suspected causes for a sharp increase in dugong deaths, which rose from an average of 13 per year to over 40 in 2023 and 2024. Emaciated animals have been found stranded, and the population is now forced to migrate to unfamiliar areas in search of food, exposing them to new dangers like boat traffic and entanglement in fishing gear. In response, Thai conservation authorities have launched emergency plans that include seagrass restoration efforts and providing supplemental food like leafy vegetables.
💡Fun Facts
The dugong's closest living land relative is the elephant.
Seagrasses are not seaweed; they are true flowering plants that evolved to live in marine environments about 100 million years ago.
Dugongs are also called "sea cows" because they are herbivores that graze on underwater seagrass meadows, similar to how cows graze in pastures.
The story of Mariam, an orphaned baby dugong rescued in 2019, captured the hearts of the Thai nation and led to August 17th being named National Dugong Conservation Day.
Hat Chao Mai National Park is generally open daily, but boat tours to view the seagrass meadows and potentially spot dugongs depend on tides and weather.
Admission
There is an entrance fee for Hat Chao Mai National Park. Boat tours are arranged separately with local operators from piers like Hat Yao Pier.
Accessibility
The area is a marine and coastal environment. Access to the seagrass meadows is by long-tail boat. Dugong sightings are not guaranteed and are best attempted with experienced local guides.