A dugong is spotted in waters off Yongshu Reef near China’s Nansha Islands. Photo: Screenshot from a video by Chinese Academy of Sciences’ South China Sea Institute of Oceanology
A dugong, one of the oldest marine mammals on Earth and often called a “mermaid” in folklore, has been spotted multiple times since mid-July in waters off Yongshu Reef in China’s Nansha Islands, marking the first such sightings in the area and the central South China Sea over the last three decades, according to the Chinese Academy of Sciences’ South China Sea Institute of Oceanology on its official WeChat account on Thursday.
The herbivorous mammal, which is said to have inspired mermaid legends, is the only extant marine species in the Dugongidae family of the order Sirenia. It is listed as vulnerable on the International Union for Conservation of Nature Red List of Threatened Species and categorized as a national first-class protected wildlife species in China.
Grow up to three meters in length, dugongs play a vital role in maintaining seagrass bed vitality and habitat biodiversity. The last confirmed dugong sighting from the Chinese mainland was a dead specimen found in the city of Dongfang, South China’s Hainan Province in 2008. The species was reported to be functionally extinct in the coastal waters of the Chinese mainland in 2022.
According to the post, dugong activity has been repeatedly observed near the reef. On July 8, patrol staff at Yongshu Reef first noticed a “large fish” surfacing for air southwest of the reef. Over a month, they repeatedly observed it in the same area. On August 2 and 3, Chinese scientists and patrol staff recorded close-up images twice. Researchers verified the “large fish” was a dugong. The most recent sighting came on August 11.
“In the past six months, after sightings of nationally protected species like hawksbill turtles and green sea turtles, researchers have for the first time recorded sustained activity of the critically endangered dugong in the waters near Yongshu Reef. It also fills a gap in species distribution and represents the first scientifically documented living dugong in the central South China Sea in nearly 30 years,” said the post.
According to the post, dugongs usually travel in small family groups of two or three, and it remains unclear why this individual appeared alone, which requires further monitoring and investigation.
Qin Geng, a researcher at the South China Sea Institute of Oceanology, said dugong populations along China’s northern South China Sea coast — including Guangxi and Guangdong — collapsed between the late 20th and early 21st centuries. While fishermen have occasionally reported sightings farther south, there had never been confirmed images or specimens from research institutions.
The discovery, together with a March 2025 record from the island of Taiwan, provides precious evidence of dugongs in Chinese waters over the past decade and offers key clues to how the species may be migrating across regions under the combined influences of climate change and human activity, according to the report.
Song Xingyu, a researcher at the South China Sea Institute of Oceanology, said that green sea turtles rely on sandy beaches to reproduce, hawksbill turtles depend on healthy coral reefs and dugongs signal the integrity of seagrass ecosystems. The successive sightings of all three species around Yongshu Reef highlight the unique ecological value of the area and reflect China’s progress in reef conservation and restoration, according to the post.
The reef’s coral formations, seagrass beds and nesting beaches have provided vital habitats for marine life and demonstrate the continued health of the South China Sea’s island ecosystems, noted Song.
Global Times