Hunting and habitat destruction to blame for the disappearance of ‘sea cows’ in Chinese waters, scientists say

Ancient records describe the animals as ‘mermaids’ that ‘haunt the sea’ and are ‘able to weave’

The dugong, a marine mammal found in coastal areas of the Pacific and Indian oceans, is now functionally extinct in Chinese waters, according to a new paper.

Researchers from the Zoological Society of London (ZSL) and the Chinese Academy of Sciences reached that conclusion after conducting a large-scale survey of fishermen, sailors and other maritime industry workers in four Chinese provinces and reviewing records of reported dugong activity.

Just three out of the 788 respondents in their survey reported dugong sightings in the past five years - none of which were backed by evidence. With no verified field observations since 2000 and a lack of other records after 2008, the researchers concluded the animals experienced rapid population collapse and were now functionally extinct in China.

"This is the first functional extinction of a large vertebrate in Chinese coastal waters," said Lin Mingli, lead author of the paper published in Royal Society Open Science on Wednesday.

The dugong is a docile mammal that moves slowly along shallow seabeds and feeds on seagrass, resting on reefs after a full meal. It has poor eyesight but excellent hearing.

The animals have inspired Chinese legends about mermaids. When a female dugong nurses her young, she sticks her head out of the water and holds the calf with her flippers. From a distance, the dugong looks like a woman breastfeeding a baby, according to a 2019 report in Science and Technology Daily.

The Shu Yi Ji, written during the Southern dynasties (420AD to 589AD), contains an early record of the animals: "There are mermaids in the South China Sea in the shape of fish. They haunt the sea and are able to weave, and droplets fall from their eyes when they cry."

Researchers said widespread habitat degradation and hunting were the main contributors to the collapse of the dugong population.

Lin's paper said the animals' habitat overlapped with areas for fishing and other marine activity, "making them vulnerable to human pressures".

Dugongs have been classified as a "Grade 1 National Key Protected Animal" by China's State Council since 1988, but the designation did not reverse their falling numbers.

Humans have destroyed most their habitats. Although restoration and recovery efforts have been made in China, they were likely too late, according to marine biologists.

For at least 4,000 years, humans hunted dugongs for their oil, bones and hides. Other major threats to dugongs include coastal development, pollution, fishing activities and attacks by boats.

"The likely disappearance of dugongs in China was a devastating loss," said Professor Samuel Turvey of ZSL's Institute of Zoology, a co-author of the study, in an interview with Reuters.

According to the researchers, the loss of the species could have a knock-on effect on ecosystem function and raises concerns about threats to other marine mammals.

In December 2019, land-reclamation projects for US military bases on the Japanese island of Okinawa affected nearby dugongs, according to a report by Shanghai-based news outlet Guancha.

Most of the world's remaining dugongs are found along the northern coast of Australia. Even in protected areas, some of the "sea cows" are still killed by poachers and die accidentally from fishing gear and shark nets.

Earlier this year, two well-known fish species - the Chinese paddlefish and Yangtze sturgeon - were also declared extinct.

The scientists said that the extinction of dugongs in China should raise the public's awareness about pollution, marine habitats and species loss caused by human activity.

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