Abstract:

Aims: As the frame-work organisms of coral-reef eco-systems, species community structure of reef-building corals play 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 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. We use SCUBA diving and video survey from June 2023 and June 2024 to reveal the species diversity and distribution characteristics of reef-building corals in the reserve. 

Results: Our results show 34 species of reef-building corals are distributed in the National Nature Reserve of Guangdong Nanpeng Islands, belonging to 19 genera and 9 families. Most of these are 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 coral coverage among the islands, followed by Nanpeng and Zhongpeng Islands, with Qinpeng Island having the lowest coverage. 

Conclusions: We investigate the species diversity and distribution characteristics of reef-building corals in the National Nature Reserve of Guangdong Nanpeng Islands. Our findings contribute to the scientific understanding of the current status of reef-building coral communities in Nanpeng Islands Marine ecology National Nature 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 of Guangdong Nanpeng Islands, species diversity, community characteristics