Chinese dugongs now declared extinct
Dugongs, the pudgy marine mammals that once inspired homesick sailors’ fanciful tales of mythical mermaids, are now extinct in China, new research shows. For hundreds of years, these gentle giants, commonly known as sea cows, have swum in Chinese waters, ripping up seagrasses on the ocean bottom with a flexible upper lip. But with no sea cow sightings confirmed in the region for more than two decades, an international team of scientists recently undertook an in-depth investigation, surveying local fishing communities across four Chinese provinces and searching for evidence of the missing dugongs (Dugong dugon).
Historical records of dugongs peaked around 1960 and then decreased rapidly from 1975 onward. No verified sightings by fishers, for instance, are recorded after 2008, and scientists in China haven’t spotted a dugong in the wild since 2000. “Based on these findings, we are forced to conclude that dugongs have experienced rapid population collapse during recent decades and are now functionally extinct in China,” the scientists wrote.
Dugongs have plump bodies, broad, droopy faces and a flattened, fluked tail like a dolphin’s. Adults measure up to four metres long and can weigh more than 400 kilograms. They resemble manatees, which are also referred to as sea cows but while manatees inhabit freshwater ecosystems, dugongs dwell in shallow tropical ocean habitats from East Africa to Vanuatu. Sea cows nibble on seagrasses much as terrestrial cows graze in lush meadows on land, and they are the only marine mammals that subsists on an exclusively vegetarian diet.
Neither manatees nor dugongs resemble humans, let alone alluring women with long hair and fishlike tails. But sailors at sea likely glimpsed these animals only very briefly – just long enough to inspire fanciful accounts of mermaids diving beneath the waves. However, the real-world story of humans and dugongs is no fairy tale. Because dugongs graze near coastlines, they are often struck by boats and caught in fishers’ nets, and human activities have dramatically reduced or destroyed their coastal habitats.
A handful of people have anecdotally reported seeing a dugong in Chinese waters in the last five years, but those sightings were never verified, the authors of the new study discovered in their surveys. So while it’s possible that some individual dugongs may yet survive in the northern South China Sea, it’s also likely that the recently spotted animals were misidentified or were stragglers belonging to more stable dugong populations near the Philippines. What’s more, the study found that “the dramatic population decline experienced by the species in recent decades is highly unlikely to be halted or reversed under current conditions.”
“The likely disappearance of the dugong in China is a devastating loss,” said Samuel Turvey, professor at the Zoological Society of London’s Institute of Zoology. “Their absence will not only have a knock-on effect on ecosystem function, but also serves as a wake-up call – a sobering reminder that extinctions can occur before effective conservation actions are developed.”