Researchers in China have declared the dugong extinct in the country’s coastal areas.

One of the ocean’s gentle giants, the dugong is a slow-moving herbivore heavily reliant on seagrass communities for its diet, making it the only truly vegetarian marine mammal.

Its slow pace and peaceful nature are seen as possible reasons for its demise in Chinese coastal waters as it can be susceptible to overfishing and shipping accidents.

Research conducted by the Zoological Society of London and the Chinese Academy of Science found no known sightings by scientists in the area since 2000. Turning to local knowledge, the researchers questioned 788 local people in Chinese coastal communities where just three said they had seen one in the last five years.

The average length of time to the last sighting was 23 years.

The dugong has been hunted for thousands of years for its meat and oil, and traditional hunting still has great cultural significance in several countries, particularly in northern Australia and the Pacific Islands.

The dugong’s current distribution is fragmented, and many populations are believed to be close to extinction. The International Union for Conservation of Nature lists the dugong as a species vulnerable to extinction, while the Convention on International Trade in Endangered Species limits or bans the trade of derived products.

With a long lifespan of 70 years or more, and a slow rate of reproduction, the dugong is especially vulnerable to extinction, but remains in a number of areas in the Indian and western Pacific Oceans.