China's Ministry of Ecology and Environment has released a survey report on the Huangyan Dao Blue Hole in the South China Sea.⁣ ⁣ The report identifies it as China's first coral reef blue hole and a globally rare coral reef growth structure. Researchers estimate it formed at least 3,200 years ago and found it supports rich marine biodiversity.⁣ ⁣ #China #SouthChinaSea #HuangyanDao #marine #biodiversity #ecology