The dugong, an ocean mammal once mistaken for mermaids by sailors, has been declared “functionally extinct” in China.
New research shows a rapid decline in numbers in the country from the 1970s and found no data or evidence of the dugong dugon since 2008.
They are threatened worldwide by human activities such as fishing, ship collisions and human-induced habitat loss.
Conservation scientists at the Zoological Society of London (ZSL) and the Chinese Academy of Sciences conducted surveys and looked at historical distribution data to come to the sad conclusion.
Co-author Professor Samuel Turvey said: ‘The likely disappearance of the dugong in China is a devastating loss.
“Their absence will not only have a knock-on effect on ecosystem function, but also serve as a wake-up call — a sobering reminder that extinction can occur before effective conservation actions are developed.”
Conservation scientists from the Zoological Society of London (ZSL) and the Chinese Academy of Sciences conducted studies and reviewed historical distribution data to come to the sad conclusion that dugongs in China are ‘functionally extinct’
Dugongs, affectionately known as ‘sea cows’, are the only strictly herbivorous marine mammal and can grow up to three meters in length on a diet of seagrass only
Dugongs, affectionately called ‘sea cows’, are the only strictly herbivorous marine mammal and can grow up to three meters in length on a diet of only seagrass.
They have been known to exist in southern China for hundreds of years, but they can also be found in coastal waters from eastern Africa to Vanuatu, and as far north as the southwestern islands of Japan.
However, they are globally threatened and listed as vulnerable by the International Union for Conservation of Nature (IUCN).
The gentle giants have also been classified as a Grade 1 National Key Protected Animal since 1988 by the Chinese State Council – the highest protection the country offers.
To assess their conservation status, dugong surveys were conducted in 66 fishing communities in Hainan, Guangxi, Guangdong and Fujian provinces.
Heidi Ma, a postdoctoral researcher at ZSL’s Institute of Zoology, said: ‘Through surveys, we have gathered valuable information previously unavailable for making fact-based assessments of the status of dugongs in the region.
“This not only demonstrates the usefulness of ecological knowledge to understand the status of species, but also helps us engage local communities and explore possible causes of wildlife decline and possible solutions for mitigation.”
While the researchers wanted to gain knowledge from recent sightings in the South China Sea from local people, they found no evidence for the survival of the species.
In the newspaper, released today in Royal Society Open Sciencethe authors therefore recommend that the regional status of the species should be reassessed as critically endangered (possibly extinct).
However, they say they would “welcome any possible future evidence” that dugongs could still exist in China.
To assess their conservation status, dugong surveys were conducted in 66 fishing communities in Hainan, Guangxi, Guangdong and Fujian provinces. Pictured: Distribution of dugongs and survey sites in China and adjacent waters
A: Frequency distribution of 26 dugong records from last sighting from 1970 to 2019, reported by survey respondents. B: Sources of dugong sightings in the late twentieth and early twenty-first centuries, based on historical records
Professor Turvey said: ‘In 2007, we tragically documented the likely extinction of China’s unique Yangtze River dolphin.
“Our new study shows strong evidence of the regional loss of another charismatic aquatic mammal species in China – unfortunately again driven by unsustainable human activity.”
This latest study shows strong evidence that this is the first functional extinction of a large mammal in China’s coastal waters.
One possible reason for the decline is that the dugong relies on seagrass as both a habitat and a food source, as it is rapidly degraded by human influences.
Seagrass restoration and restoration is a priority in the country, but these projects will take time to have an impact on the species.
The loss of the dugong highlights the need for effective evidence-based conservation strategies for endangered marine mammals.
The researchers call on world leaders to make biodiversity loss part of wider policy planning and to help prevent further losses.