Dugongs are gentle, herbivorous marine mammals inhabiting coastal waters across the Indo-Pacific, from East Africa to Australia. Often called “sea cows,” they graze on seagrasses in shallow bays, estuaries, and lagoons. These creatures can grow up to three meters long and weigh up to 500 kilograms, living for up to 70 years. Healthy seagrass meadows are their primary habitat and almost their entire diet.
Global Dugong Population and Status
Precise dugong population estimates are challenging due to their elusive nature and wide distribution across approximately 40 countries. Current estimates suggest a global population of around 100,000 individuals. This global figure, however, masks significant regional variations, with some populations declining severely while others remain stable.
The International Union for Conservation of Nature (IUCN) Red List classifies the dugong as “Vulnerable” globally, a status held since 1982, indicating a high extinction risk. Some subpopulations are in a more precarious state. The East Africa subpopulation is “Critically Endangered,” with very low estimates based on 2021 aerial surveys. The New Caledonian subpopulation is “Endangered,” with estimates from 149 to 896 individuals (2003-2012 surveys).
Dugongs are functionally extinct in Chinese waters, and their numbers are rapidly dwindling in Thailand. Australia holds the largest dugong populations, with about 10,000 in Shark Bay and 20,000 in the Gulf of Carpentaria. Even in Australia, the Southern Great Barrier Reef population has declined by 2.3% annually since 2005, with approximately 2,100 individuals remaining.
Major Threats to Dugongs
Dugongs face numerous threats, primarily habitat degradation and loss. Their survival depends on seagrass beds, which are disappearing at an alarming rate globally due to human activities. Coastal development, pollution from sewage and industrial waste, and runoff from deforestation all contribute to the destruction of these underwater meadows.
Accidental entanglement in fishing gear, or bycatch, is another significant threat. Dugongs are frequently caught in nets, leading to drowning. Vessel strikes also contribute to mortality, as dugongs are vulnerable to collisions with boats and propellers, especially in shallow feeding areas.
Climate change impacts further compound these issues. Ocean warming and extreme weather events directly affect seagrass meadows, which are already declining globally. This loss of their primary food source can lead to starvation, as seen in Thailand where seagrass depletion increased dugong fatalities. Historically, hunting also contributed to population decline, but current pressures primarily stem from these anthropogenic factors.
Protecting Dugongs for the Future
Conservation efforts for dugongs are multifaceted, recognizing the complex threats they face. The Dugong and Seagrass Conservation Project, a coordinated global initiative, works across eight Indo-Pacific countries to enhance dugong and seagrass ecosystem protection. This project emphasizes community participation, as local engagement is fundamental for long-term success.
Establishing marine protected areas (MPAs) is a primary strategy, providing safe havens where dugongs and their seagrass habitats can thrive. Regulatory measures are also implemented to reduce bycatch, a major cause of dugong deaths. Public awareness campaigns educate communities about dugongs and their conservation, aiming to encourage sustainable practices. Research and monitoring programs are ongoing to understand dugong distribution and pressures, which informs management strategies. Efforts to mitigate climate change impacts are also important, given the species’ reliance on healthy seagrass ecosystems.