The cumulative impact of annual coral bleaching can turn some coral species winners into losers
The cumulative impact of annual coral bleaching can turn some coral species winners into losers
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DOI：
10.1111/gcb.12658
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发表时间：
2014-12-01
影响因子：
11.6
通讯作者：
Matsui, Yohei
中科院分区：
文献类型：
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作者：
Grottoli, Andrea G.;Warner, Mark E.;Matsui, Yohei
海水温度升高造成的大规模珊瑚漂白事件导致整个热带地区的珊瑚大量丧失，预计其频率和严重程度将增加。如果白化现象在本世纪成为一个年度事件，全球90%以上的珊瑚礁可能面临长期退化的风险。虽然珊瑚可以从单一的孤立漂白中恢复，并可以适应相隔多年的反复漂白事件，但目前尚不清楚它们是否以及如何生存并可能适应每年的珊瑚漂白。在这里，我们首次证明，每年的珊瑚漂白可以显着改变加勒比海珊瑚的耐热性。我们发现，高珊瑚能源储备和变化的优势藻类内共生体类型（共生藻属）。促进了快速驯化的滨珊瑚divaricata，而低能量储备和缺乏藻类表型可塑性显着增加的敏感性在滨珊瑚astreoides漂白次年。表型可塑性的优势内共生体类型的Orbicella faveolata没有防止重复漂白，但可能有利于快速恢复。因此，珊瑚holobiont响应一个孤立的单一漂白事件是不是一个准确的预测其响应漂白次年。相反，每年珊瑚白化的累积影响可以把一些珊瑚物种的赢家'变成输家'，也可以促进适应，把一些珊瑚物种的输家'变成赢家'。总体而言，这些研究结果表明，每年珊瑚漂白的累积影响可能导致一些物种变得越来越容易受到漂白的影响，并面临长期衰退，而表型塑料珊瑚物种将适应并持续存在。因此，每年的珊瑚白化和恢复可能导致加勒比珊瑚多样性的选择性丧失以及珊瑚礁的全面衰退。
Mass coral bleaching events caused by elevated seawater temperatures result in extensive coral loss throughout the tropics, and are projected to increase in frequency and severity. If bleaching becomes an annual event later in this century, more than 90% of coral reefs worldwide may be at risk of long-term degradation. While corals can recover from single isolated bleaching and can acclimate to recurring bleaching events that are separated by multiple years, it is currently unknown if and how they will survive and possibly acclimatize to annual coral bleaching. Here, we demonstrate for the first time that annual coral bleaching can dramatically alter thermal tolerance in Caribbean corals. We found that high coral energy reserves and changes in the dominant algal endosymbiont type (Symbiodinium spp.) facilitated rapid acclimation in Porites divaricata, whereas low energy reserves and a lack of algal phenotypic plasticity significantly increased susceptibility in Porites astreoides to bleaching the following year. Phenotypic plasticity in the dominant endosymbiont type of Orbicella faveolata did not prevent repeat bleaching, but may have facilitated rapid recovery. Thus, coral holobiont response to an isolated single bleaching event is not an accurate predictor of its response to bleaching the following year. Rather, the cumulative impact of annual coral bleaching can turn some coral species winners' into losers', and can also facilitate acclimation and turn some coral species losers' into winners'. Overall, these findings indicate that cumulative impact of annual coral bleaching could result in some species becoming increasingly susceptible to bleaching and face a long-term decline, while phenotypically plastic coral species will acclimatize and persist. Thus, annual coral bleaching and recovery could contribute to the selective loss of coral diversity as well as the overall decline of coral reefs in the Caribbean.