Abstract:

Aims: Reef-building corals are the framework organisms of coral-reef ecosystems, and their community structure plays a major role in biodiversity. The Tropic of Cancer is the northernmost distribution line of reef-building corals along the coast of China. However, there are relatively few studies on reef-building corals in high-latitude regions, and information on species diversity and community distribution characteristics in these areas remains unclear. 

Methods: The National Nature Reserve for Marine Ecology of Guangdong Nanpeng Islands (hereinafter referred to as Nanpeng Islands Reserve) is one of the northernmost reserves in China with records of the distribution of reef-building corals. The diversity and distribution patterns of reef-building coral species in the protected area were investigated through diving surveys in June 2023 and June 2024. 

Results: Our results show 34 species of reef-building corals are distributed in the Nanpeng Islands Reserve, belonging to 19 genera and 9 families. Most of these are massive and encrusting with Psammocora nierstraszi and P. profundacella occupying dominance. Reef-building corals exhibit typical high-latitude patchy community distribution characteristics, with non-reef-forming and low coverage within the protected area. Dingpeng Island has the highest average coverage of reef-building coral, followed by Nanpeng Island and Zhongpeng Island, with Qinpeng Island having the lowest coverage. 

Conclusions: We investigate the species diversity and distribution characteristics of reef-building corals in the Nanpeng Islands Reserve. Our findings contribute to the scientific understanding of the current status of reef-building coral communities in the Nanpeng Islands Reserve. Additionally, we provide much needed data for the protection and research of coral communities in the northern margin of the South China Sea.

Key words: reef-building corals, the National Nature Reserve for Marine Ecology of Guangdong Nanpeng Islands, species diversity, community characteristics