Chinese researchers on Wednesday said that they have confirmed the presence of a dugong – one of the oldest marine mammals on Earth and the inspiration behind mermaid legends – in waters off Yongshu Reef in China's Nansha Islands area.

This marks the first such sighting in the area and in the central South China Sea over the last three decades.

Dugong sighted off South China Sea reef (Image by CMG)

Dugong activity has been repeatedly observed near the reef since early July, according to researchers at an ecological and environmental research station operated by the Chinese Academy of Sciences' (CAS) South China Sea Institute of Oceanology. They noted that the sightings fill a species-distribution gap for the area.

The dugong is the only marine mammal on the planet that feeds entirely off sea grass, and the only extant marine species in the family Dugongidae 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.

Island environmental patrols first spotted the large animal surfacing for air southwest of the reef on July 8. Close-range observations were made and video evidence was captured on August 2 and August 3, CAS experts have verified.

"This discovery provides crucial clues about the species' transoceanic migration patterns under the dual stressors of climate change and human interference," said marine researcher Qin Geng, who works at the institute.

Dugongs can grow up to three meters in length and play a vital role in maintaining seagrass bed vitality and habitat biodiversity. The last confirmed dugong sighting from Chinese mainland was a dead specimen found in Dongfang City in the southern island province of Hainan in 2008. The species was reported to be functionally extinct in the coastal waters of the Chinese mainland in 2022.
Scientists say that dugongs usually form small family groups of two to three individuals, making this lone appearance an anomaly that requires further monitoring and investigation.

CAS researcher Song Xingyu noted that the dugong sighting complements earlier recorded sightings of protected green sea turtles and hawksbill turtles near Yongshu Reef, underscoring the reef's ecological value. "The dugong's presence confirms the integrity of seagrass ecosystems in the area," he said. (CGTN)

Dugong 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. (Image by CMG)