A green sea turtle nesting site has been discovered recently for the first time on a reef in the Nansha Islands in the South China Sea, according to sources from an ecological and environmental research station under the South China Sea Institute of Oceanology, Chinese Academy of Sciences.

The discovery was a result of routine ecological environment monitoring supported by the institute's island and reef research center.

During the monitoring, researchers found a roughly 30-centimeter-deep, irregularly circular depression on the sandy beach area of Yongshu Reef, part of the Nansha Islands, with overturned sand grains scattered around it.

The features closely align with the typical nesting behavior of green sea turtles, suggesting that the depression was left behind as a trace of a turtle nesting site.

By deploying surveillance equipment and conducting nighttime patrols during a joint investigation in collaboration with the reef-based environmental protection departments, researchers successfully obtained visual records of sea turtles engaging in activities on the beach, including coming ashore and returning to the ocean.

Additionally, samples of sea turtle eggs with typical characteristics, including clean and tough eggshells approximately 4 cm in diameter, were collected from the site and confirmed to be green sea turtle eggs.

Based on these findings, researchers ultimately confirmed that the reef area has indeed become a nesting site for green sea turtles.

Field surveys also revealed flipper crawl marks on the sandy ground, extending to the edge of the seawater, indicating the path of sea turtles landing and returning to the ocean.

Sea turtle eggs collected during the investigation are tightly arranged and enveloped in a moist layer of sand. The findings provide valuable materials for studying the reproductive behavior of green sea turtles.

As a nationally first-class protected species, the newly discovered nesting site holds significant importance in strengthening the conservation efforts for this species, according to researchers.

Located approximately 800 kilometers south of previously discovered nesting sites like those on North Island of the Xisha Islands, the new site confirms that the excellent marine ecological environment in the South China Sea provides suitable habitat conditions for endangered species like the green sea turtle.

The ecological and environmental research station will collaborate with the environmental protection departments to implement protective monitoring in the area and launch monitoring of relevant environmental factors, laying the foundation for subsequent hatching studies.

The discovery will drive the improvement of the South China Sea island reef ecosystem protection system and contribute new data to the global sea turtle conservation network, researchers said.

China has tightened its efforts in the protection of green sea turtles in recent years. At the largest natural nesting site for the species on the North Island of the Xisha Islands, professional patrol teams guard the area around the clock, especially during peak breeding season from June to September each year.

Marine protection authorities in Sansha of Hainan province have organized professional patrol teams comprising researchers and fishermen on the islands, covering more than 10 islets.

In 2024 alone, a total of 227 protected sea turtle nests were marked and 77 injured or sick sea turtles were rescued on the Xisha Islands, with the survival rate of hatchlings being significantly improved compared to the time before 2020.

"Every new life of green sea turtles is based on the effectiveness of the protection system," said Li Yupei, senior engineer from the Sansha Marine Protection Area Management Bureau, while looking at young turtles heading towards the waves.

According to Li, local authorities have established a temporary control zone for green sea turtle protection on the North Island, further demonstrating the country's determination to protect turtles and preserve the marine ecosystem.

Since the implementation of a sea turtle protection action plan in Sansha, which took effect in 2019, over 1,500 sea turtle nests have been recorded on the main islands and reefs of the Xisha Islands through intelligent monitoring and habitat restoration efforts.

qiuquanlin@chinadaily.com.cn