Main photo credit: Fabrice Dudenhofer / Ocean Image Bank
Dugongs (Dugong dugon) are the only member of their family. They are also the only marine mammal which is strictly herbivorous. They live in coastal, warm water in 37 countries. Dugongs have been documented in China for hundreds of years, but now scientists have concluded that they are functionally extinct there.
Named from the Malay for “Lady of the Sea”, Dugongs are said to have inspired the legends of mermaids.
Dugongs are natural prey for sharks, killer whales and crocodiles, but they are most vulnerable to human activities. Hunting has drastically reduced dugong populations in some areas and the dugong habitat of seagrass beds is under pressure from coastal development, pollution, marine construction trawling, gill nets and other degradation. They are listed as Vulnerable on the IUCN Red List of Threatened Species.
Part of the problem for Dugongs is their longevity and their slow rate of reproduction. They have only one calf at a time and nurse their baby for a year and a half. The young dugong might stay with the mother until she gives birth again, which can be as much as seven years later. Even in the best of conditions populations might only increase by 5% per year. When dugongs do not have enough seagrass to eat they delay breeding.
The study was published in in Royal Society Open Science and undertaken by an international team of scientists from China, the UK and Greece.