Journal of Tropical Oceanography ›› 2024, Vol. 43 ›› Issue (3): 58-71.doi: 10.11978/2023118CSTR: 32234.14.2023118

• Marine Biology • Previous Articles     Next Articles

Community structure of scleractinian corals in the northern South China Sea and their responses to the marine heatwaves

XU Lijia1(), LIAO Zhiheng2, CHEN Hui3, WANG Yongzhi1(), HUANG Baiqiang1, LIN Qiaoyun1, GAN Jianfeng1, YANG Jing1   

  1. 1. South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510535, China
    2. Key Laboratory of Environment Change and Resources Use in Beibu Gulf (Nanning Normal University), Ministry of Education, Nanning 530001, China
    3. Guangdong Provincial Academy of Environmental Science, Guangzhou 510045, China
  • Received:2023-08-13 Revised:2023-10-20 Online:2024-05-10 Published:2024-06-04
  • Supported by:
    National Natural Science Foundation of China(42277362); National Natural Science Foundation of China(41806139); Science and Technology Planning Project of Guangzhou City(202002030345); Central Public-Interest Scientific Institution Basal Research Fund(PM-zx703-202105-176); Central Public-Interest Scientific Institution Basal Research Fund(PM-zx703-202004-143)

Abstract:

Coral communities in the northern South China Sea (SCS), which have the potential to act as regions of refugia for many coral species in the face of global warming. However, the temporal and spatial diversities of coral communities in the northern SCS and the effects of coral bleaching caused by marine heat waves are still unclear. In this study, the status of coral communities across the northern SCS, including the Daya Bay, the Weizhou Island, the Xuwen and Luhuitou fringing reefs, and the space differences are studied on the basis of ecological materials in the field investigations during August 2020, and its response to marine heatwaves. Our results indicate that coral communities across the northern SCS show remarkable regional characteristics. The dominant species composition, species number and α diversity index of coral communities are subject to significant regional differences, and the live coral cover is higher in the Luhuitou and Daya Bay (37.78% and 17.97%, respectively). Thus, the coral communities in Xuwen and Weizhou were subject to mass coral bleaching events during the field investigation, and the coral bleaching rate and mortality rate was 84.78% and 10.68%, 65.52% and 0.70% in Xuwen and the Weizhou Island, respectively, while no coral bleaching occurred in the Daya Bay and Luhuitou. Based on historical data analysis, although the live coral cover of coral communities in the northern SCS has dropped significantly since 1980s, there has been a recovery trend in recent years; the proportion of heat bleaching tolerant genera and heat bleaching resistant genera increased in the coral communities of the Weizhou Island, Xuwen and Luhuitou. In general, the coral community in the northern SCS has a strong resistance to heat bleaching. Strengthening the conservation and management of coral reef areas is crucial for the restoration and refuge of coral communities in the northern SCS under global warming.

Key words: coral reef, scleractinian coral, species diversity, coral bleaching, northern South China Sea