热带海洋学报 ›› 2024, Vol. 43 ›› Issue (3): 87-99.doi: 10.11978/2023115CSTR: 32234.14.2023115

• 海洋生物学 • 上一篇    下一篇

西沙群岛银屿珊瑚礁的生态快速退化及其对鱼类的影响

雷明凤1(), 余克服1,2,3(), 廖芝衡3,4, 陈飚1,2,3, 黄学勇1,2,3, 陈小燕1,2,3   

  1. 1.广西大学海洋学院, 广西 南宁 530004
    2.广西大学珊瑚礁研究中心, 广西 南宁 530004
    3.广西南海珊瑚礁研究重点实验室, 广西 南宁 530004
    4.南宁师范大学北部湾环境演变与资源利用教育部重点实验室, 广西 南宁 530001
  • 收稿日期:2023-08-09 修回日期:2023-10-22 出版日期:2024-05-10 发布日期:2024-06-04
  • 作者简介:

    雷明凤(1999—), 女, 广西桂林市人, 硕士研究生, 从事海洋生物生态研究。email:

  • 基金资助:
    国家自然科学基金项目(42090041); 国家自然科学基金项目(42030502)

The rapid ecological degradation and its impact on fish of the Yinyu Island in the Xisha Islands

LEI Mingfeng1(), YU Kefu1,2,3(), LIAO Zhiheng3,4, CHEN Biao1,2,3, HUANG Xueyong1,2,3, CHEN Xiaoyan1,2,3   

  1. 1. School of Marine Sciences, Guangxi University, Nanning 530004, China
    2. Coral Reef Research Center of China, Guangxi University, Nanning 530004, China
    3. Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Nanning 530004, China
    4. Key laboratory of Beibu Gulf Environment Change and Resources Utilization of Ministry of Education, Nanning Normal University, Nanning 530001, China
  • Received:2023-08-09 Revised:2023-10-22 Online:2024-05-10 Published:2024-06-04
  • Supported by:
    National Natural Science Foundation of China(42090041); National Natural Science Foundation of China(42030502)

摘要:

珊瑚礁生态系统退化能够改变珊瑚礁三维结构的复杂性及底栖生物组成, 从而对珊瑚礁鱼类群落产生重要影响。南海珊瑚礁在近几十年来处于快速退化之中, 但其退化对珊瑚礁鱼类群落造成的生态影响仍不清楚。西沙群岛珊瑚礁近年受高温和长棘海星暴发等的影响而出现生态退化, 因此, 本文以西沙群岛银屿珊瑚礁为研究对象, 通过水下录像样带调查和差异性检验、线性回归评估其珊瑚礁生态退化状况及其对珊瑚礁鱼类群落的影响。结果表明: 2020至2021年, 银屿活珊瑚覆盖率从33.27%下降到9.07%, 草皮海藻覆盖率从8.38%上升到36.50%, 珊瑚补充量从21.42ind.·m-2下降到3.64ind.·m-2, 珊瑚物种丰富度从40.00下降到16.83, 珊瑚Shannon-Weaner指数从3.26下降到2.14。鱼类密度从177.16ind·100m-2下降到105.07ind.·100m-2, 鱼类物种丰富度从30.56下降到17.17, 鱼类Shannon-Weaner指数从2.24下降到1.63, 珊瑚食性鱼类生物量从2.45g·m-2减少到0.43g·m-2, 肉食性鱼类生物量从7.35g·m-2减少到1.70g·m-2, 杂食性鱼类生物量从7.04g·m-2减少到0.95g·m-2, 鱼类总生物量从32.99g·m-2减少到11.66g·m-2。短短2年内, 银屿珊瑚礁已经被草皮海藻和大型海藻占据优势, 但是鱼类群落对珊瑚礁区的藻类并没有表现出自上而下的控制效应。在4种类群的鱼类中, 植食性鱼类受到生态退化的影响最小。珊瑚礁鱼类的物种丰富度和多样性均受限于珊瑚物种丰富度。基于以上结果, 推测银屿珊瑚礁的快速退化是导致珊瑚礁区鱼类群落物种多样性和密度下降, 改变珊瑚礁鱼类群落的结构的主要原因。希望未来进一步增加调查的频率和范围, 以便更深入地揭示鱼类群落与珊瑚礁生态变化的动态关系。

关键词: 珊瑚礁, 生态退化, 鱼类群落, 银屿, 西沙群岛

Abstract:

The degradation of coral reef ecosystem can alter the topographic complexity and biotic composition, thereby affecting the coral reef fish community significantly. Coral reefs in the South China Sea have undergone rapid degradation in recent decades, but the ecological consequences for coral reef fish community remain unclear. The coral reefs of the Xisha Islands have experienced ecological degradation in recent years due to the impacts of high temperature and the outbreak of crown-of-thorns starfish (CoTs). We conducted an ecological investigation on the Yinyu Island of the Xisha Islands, through underwater video transect survey, difference tests and liner regression analysis to assess the ecological degradation of the coral reef and its effect on the coral reef fish community. The results show that: from 2020 to 2021, the live coral cover on the Yinyu Island declined from 33.27%to 9.07%, while the turf algae cover increased from 8.38%to 36.50%. The coral recruitment, species richness and Shannon-Weaner index also decreased from 21.42 ind·m-2 to 3.64 ind·m-2, 40.00 to 16.83 and 3.26 to 2.14, respectively. The fish density, species richness, Shannon-Weaner index, declined from 1.77 ind.·m-2 to 1.05 ind.·m-2, 30.56 to 17.17 and 2.24 to 1.63, respectively. The biomass of corallivore, carnivore, omnivore and total biomass also declined from 2.45 g·m-2 to 0.43 g·m-2, 7.35 g·m-2 to 1.70 g·m-2, 7.04 g·m-2 to 0.95 g·m-2, and 32.99 g·m-2 to 11.66 g·m-2, respectively. Within two years, turf algae and macroalgae have dominated the Yinyu Island, but the fish community has not demonstrated top-down control of algae. Among the four functional groups in the whole fish community, the herbivore functional group is the least affected by ecological degradation. The coral species richness constrains the fish species richness and diversity. Based on the results above, we speculate that the rapid degradation of the Yinyu Island is the main reason for the decreased in species diversity, density and the change in the structure of coral reef fish communities. We hope to further increase the frequency and scope of investigations in the future, in order to reveal more deep dynamic relationship between fish communities and coral reef ecological changes.

Key words: coral reef, ecological degradation, fish community, Yinyu, Xisha Islands