Hainan marks World Oceans Day with rare slug sighting and coral recovery data

On the 18th United Nations World Oceans Day and China's 19th National Ocean Awareness Day, which both fell on Monday, new signs of marine recovery have emerged off Hainan province.

In May, a rare leaf sheep sea slug was spotted and photographed in the Wuzhizhou Island waters off Sanya. The tiny species is highly sensitive to water quality, as it photosynthesizes by incorporating chloroplasts from algae. The sighting underscores improving marine ecology and a stable, biodiverse reef system, local authorities said.

Since 2011, Sanya has operated China's first tropical marine ranch project at the Wuzhizhou Island tourism zone, focusing on coral restoration. To date, more than 80,000 cubic meters of artificial reefs have been deployed, over 50,000 high-quality coral seedlings cultivated and transplanted, and 53,000 square meters of coral restored.

After six years, coral coverage in the area increased from 23 percent to 41 percent, with survival rates above 80 percent. The project has been recognized nationally as a model for marine ecological restoration.

In Sanya Bay, drones and underwater robots helped plant 32,000 coral colonies.

Sanya's nearshore waters have maintained 100 percent good water quality year-round, with Wuzhizhou Island's waters meeting a national Class I standard for 18 consecutive months.

On Sunday evening in Rongshanliao village, Haikou, more than 100 volunteers collected bags of plastic waste, discarded fishing nets, and debris during a beach cleanup.

Marine education programs in schools are also expanding to foster conservation awareness among youth.