Rapid decline of a relatively high latitude coral assemblage at Weizhou Island, northern South China Sea
Rapid decline of a relatively high latitude coral assemblage at Weizhou Island, northern South China Sea
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DOI：
10.1007/s10531-019-01858-w
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发表时间：
2019-09
影响因子：
3.4
通讯作者：
Wan Yu;Wenhuan Wang;Kefu Yu;Yinghui Wang;Xueyong Huang;Rongyong Huang;Zhiheng Liao;Shendong Xu;Xiaoyan Chen
中科院分区：
文献类型：
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作者：
Wan Yu;Wenhuan Wang;Kefu Yu;Yinghui Wang;Xueyong Huang;Rongyong Huang;Zhiheng Liao;Shendong Xu;Xiaoyan Chen
“避难所理论”表明，全球变暖将有利于高纬度水域的珊瑚。因此，从理论上讲，位于南中国海北部较高纬度地区(21°00‘-21°10’N，109°00‘-109°15’E)的蔚州岛礁是全球变暖下珊瑚的避难所。然而，这里的珊瑚已经严重退化。2015年，我们对蔚州岛珊瑚礁的生态状况进行了调查，共记录到珊瑚11科22属41种。平均活珊瑚覆盖率已从1984年的~ 42%下降到2015年的~ 10%，研究区域内有许多死亡珊瑚，特别是在礁坪。珊瑚组合结构经历了退化，优势类群从高度复杂的分枝、叶状和块状群体向更简单的块状形态类群转变。表明这里的珊瑚受益于全球变暖的唯一迹象是出现了大量的幼珊瑚黄斑(占总人口的31.91%)，这代表了蔚州岛珊瑚礁的恢复潜力。进一步分析认为，快速退化的主要原因是不断升级的人为影响，如海水污染、不可持续的旅游活动、持续的过度捕捞，所有这些都破坏了当地的生态环境。人类密集的活动似乎大大削弱了避难所的功能。活珊瑚盖度的减少和组合结构的退化都表明，在全球变暖和人类活动加剧的背景下，蔚州岛作为珊瑚避难所的潜力有限。
“Refuge theory” suggests that global warming would be beneficial to corals in high latitude waters. In theory, then, the Weizhou Island reef (21°00′–21°10′N, 109°00′–109°15′E), which is located in a relatively high latitude area in the northern South China Sea, is a refuge for corals under global warming. Yet, the corals here have degenerated significantly. We investigated the ecological status of the Weizhou Island reef in 2015 and recorded 11 families, 22 genera, and 41 coral species. The mean living coral cover has decreased from ~ 42% in 1984 to ~ 10% in 2015 and there are many deadAcroporain the study area, especially at the reef flat. Coral assemblage structure has undergone degradation with the dominant group shifting from high complexity branching, foliaceous and massive colonies to a simpler group of massive morphologies. The only sign indicating the corals here benefiting from global warming is the occurrence of a large amount of juvenilePorites lutea(31.91% of the total population), which represents the recovery potential of the Weizhou Island reefs. Further analysis concludes that the main reason for the rapid degeneration is escalating anthropogenic impact, such as seawater pollution, unsustainable tourism activities, ongoing overfishing, all of which degrade the local ecological environment. It seems that intensive anthropogenic activities have weakened the “refuge” function significantly. Decreasing living coral cover as well as degraded assemblage structure all suggest that Weizhou Island offers limited potential as refuge habitat for corals in the context of global warming and intensive human activities.