China Discovers Rare Coral Reef Blue Hole in South China Sea -

China has identified its first coral reef blue hole in the waters off Huangyan Island in the South China Sea, with scientists describing the underwater sinkhole as a biodiversity hotspot and a valuable geological archive.

According to the 2025 Survey Report on the Huangyan Island Blue Hole, released by the Ministry of Ecology and Environment, researchers used environmental DNA technology to identify more than 2,700 marine species in and around the blue hole, which was first discovered during a scientific expedition in August 2025.

Preliminary studies indicate the funnel-shaped blue hole formed at least 3,200 years ago within a dense coral reef. It has a surface diameter of 56.3 metres, a depth of 16.6 metres and covers an area of nearly 1,500 square metres.

The blue hole supports diverse marine life, including fish, giant clams, sponges, sea anemones and the endangered green sea turtle. Surveys conducted over the past two years also recorded 165 species of hard corals and 184 species of fish in the surrounding waters.

Researchers said the discovery provides important insights into the geological evolution of the South China Sea, past environmental changes and the development of coral reef ecosystems. They added that the findings could strengthen scientific understanding of marine biodiversity and support future conservation efforts.-ERMD/TS

READ MORE