Windhoek: The Huangyan Dao area in the South China Sea has maintained excellent marine environment quality, an official report said on Friday. The report found that both seawater and marine sediment quality in the area has remained at Grade I. Levels of pollutants in fish samples, including heavy metals and petroleum hydrocarbons, were all below evaluation thresholds -- while no cyanide was detected in seawater, sediments or fish.

According to Namibia Press Agency, the report was compiled by eight institutions, including institutes under the Ministry of Ecology and Environment. It drew on field surveys conducted in 2024 and 2025, satellite remote-sensing data, and historical research, to provide a comprehensive assessment of the area's marine environmental conditions, coral reef ecosystems, and seagrass habitats.

The report highlighted that Huangyan Dao's natural ecosystems exhibited strong diversity, stability, and resilience, serving as an important habitat and refuge for marine life in the South China Sea. It also offered valuable records for the study of global climate change and environmental evolution.

In particular, the coral reef ecosystem was reported to be healthy and stable. Field surveys recorded 134 species of reef-building corals, an increase of 25 from the 2024 report. Reef-associated biodiversity also remained rich, with 145 species of reef fish identified, an increase of 20 species compared with the previous year.

However, the report also warned of growing thermal stress on coral reefs in the area as climate change accelerates, elevating the potential risk of coral bleaching.

China established the Huangyan Dao national nature reserve earlier this year. It is located in the country's southernmost island city of Sansha, Hainan Province, covering an area of 3,523.67 hectares.