The waters surrounding Huangyan Island in the South China Sea have maintained good quality, with a thriving and resilient coral reef ecosystem, according to a report unveiled by the Ministry of Ecology and Environment on Friday.

The conclusion was based on field surveys conducted in 2024 and 2025, satellite remote sensing data, and historical research materials, Pei Xiaofei, the ministry's spokesman, told a news conference.

The report was compiled by eight of its affiliated research institutions, including the National Marine Environmental Monitoring Center, the ministry said.

The waters surrounding Huangyan Island continue to exhibit high-quality seawater and marine sediments, Pei said.

Testing found that residues of heavy metals and petroleum hydrocarbons in fish samples are below standard limits, and no cyanide, a strong indicator of industrial pollution, was detected in seawater, sediment, or marine life, he continued.

Pei highlighted the healthy and stable state of Huangyan Island's coral reef ecosystem. He said 134 species of reef-building corals were observed in field surveys, up by 25 from the previous year, with an average live coral cover of 29.8 percent and a high density of coral juveniles.

The field surveys also found rich biodiversity around the reefs, documenting 145 species of reef-dwelling fish, 20 more than in 2024, Pei said. No signs of coral disease were observed, he added.

"The report concludes that Huangyan Island's natural ecosystem demonstrates strong diversity, stability, and sustainability, providing crucial habitat and refuge for marine life in the South China Sea," Pei said. However, he warned that as climate change intensifies, the potential risk of coral bleaching around the island remains a significant concern.