The islands in the South China Sea serve as an important habitat for sea turtles, with 90 percent of China's sea turtle population found there.

"Sea turtles have a unique habit — they return to the place where they were born to lay eggs when they reach adulthood," said Li Yupei, director of the marine reserve management bureau of Sansha city in Hainan province.

"The Xisha Islands are favored nesting grounds for green turtles. By protecting the beach where they were born, generations of sea turtles will continue to return to lay eggs," he added.

Since the 1980s, the global populations and habitats of green sea turtles have seen a significant decline due to factors such as marine pollution, human activities and climate change.

An important task for Yu Yangfei, a turtle patrol officer in Sansha, is to locate the nests where turtles lay eggs during the breeding season from June to September, and assist in the conservation and monitoring of hatching, helping the young turtles return to the sea.

"The survival rate of sea turtles is very low. A typical clutch of turtle eggs may have dozens, but ultimately only around one in a thousand hatchlings can successfully evade all predators and survive to adulthood," Yu said.

In over seven years since the establishment of the protection center, Yu and his colleagues have rescued more than 280 green sea turtles and helped tens of thousands of them return to the sea.

Conservation efforts are yielding tangible results, with a total of nearly 2,000 nests containing green sea turtle eggs discovered on the Xisha Islands.