China has discovered a globally rare coral reef marine blue hole at Huangyan Dao, marking the first coral reef blue hole explored and verified in the country so far, according to a report released by the Ministry of Ecology and Environment.
Preliminary geochronological analyses, including radiocarbon dating, suggest that the blue hole dates back at least 3,200 years and supports rich biodiversity in its surrounding waters.
Titled “2025 Survey Report on Huangyan Dao Blue Hole,” the report consists of four parts, providing a comprehensive introduction to the blue hole ecosystem, the overview and genesis of the Huangyan Dao Blue Hole, the biodiversity within and around the blue hole, and prospects for research, survey and conservation.
The report said that in August 2025, scientific survey by personnel from several Chinese institutions identified a suspected “blue hole” special habitat in the central area of the Huangyan Dao lagoon.
Through comprehensive assessment, it was confirmed that the Huangyan Dao Blue Hole is a coral reef growth structure-type marine blue hole, a type rarely encountered worldwide, and the first coral reef blue hole explored and verified in China so far.
The Huangyan Dao Blue Hole developed in a high-density patch reef area within the central lagoon covering an area of 1,491.7 square meters. Preliminary geochronological analyses, including radiocarbon dating, suggest that the Huangyan Dao Blue Hole formed at least 3,200 years ago, according to the report.
A variety of typical coral reef biological communities thrive within and around the blue hole, including the green sea turtle, a wild animal protected under China’s first-class national conservation status, which inhabits the area. A cumulative total of 165 species of hard corals and 184 species of fish were recorded in the field survey, per the report.
The Huangyan Dao Blue Hole serves as a remarkable illustration of the natural ecosystem diversity of Huangyan Dao. It represents a key geological archive for reconstructing the paleoenvironmental changes of the South China Sea, including sea-level fluctuations and the impacts of global and regional climate change.
As such, it can provide critical insights into the geological evolution of the Huangyan Dao region, biodiversity and environmental changes of the South China Sea since the Holocene. Moreover, it offers essential scientific support for understanding the formation, evolutionary mechanisms, and ecological effects of this unique marine blue hole ecosystem.
Source:
Global Times, June 25, 2026. https://www.globaltimes.cn/page/202606/1364411.shtml
New China TV, June 25, 2026. https://youtu.be/Sr_3kU_1kAY
