Under the waters off of Wuzhizhou Island in Sanya, Hainan, there is a vibrant world: colorful corals are swaying while all kinds of fish swim past in every direction. 

A diver in the waters nearby Wuzhizhou Island, Sanya. (Photo provided to Hainan Daily)

However, this flourishing "kingdom under the sea" used to be an underwater “desert”, where the coral reef ecosystem was destroyed due to warming seawater, fishery operations, and construction projects along the coast.

Coral reefs, known as an "underwater rainforest", play an important role in the marine ecosystem. With the vital importance of life on the seafloor, Wuzhizhou Island has carried out coral reef restoration projects in cooperation with the South China Sea Institute of Oceanology, Chinese Academy of Sciences since 2016.

Over the past five years, over 30,000 live corals have been planted in the restoration area. Surviving the outbreak of a hostile organism—the purple drupe (Drupa Morum), the corals in the area have a survival rate of over 65% and a coverage of 37%, more than double the amount in 2016.

The restoration of coral reefs also provides a better habitat for other marine organisms and has helped create a more colorful underwater world in Wuzhizhou, where visitors can lend a hand by planting live corals while diving.

Since 2013, a total of 19 projects on ecological protection and restoration — involving 7.7 kilometers of shoreline and 51,584 square meters of sea area — have been implemented across different bays in Sanya City, including the restoration of coral reefs, shores, and beaches.