Remarkably high and consistent tolerance of a Red Sea coral to acute and chronic thermal stress exposures
Remarkably high and consistent tolerance of a Red Sea coral to acute and chronic thermal stress exposures
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DOI：
10.1002/lno.11715
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发表时间：
2021-02-15
影响因子：
4.5
通讯作者：
Barshis, Daniel J.
中科院分区：
文献类型：
--
作者：
Evensen, Nicolas R.;Fine, Maoz;Barshis, Daniel J.
由于大规模漂白事件以及最近的海洋热浪，全球变暖导致珊瑚死亡率达到前所未有的水平，海水温度迅速上升导致数天内死亡。在这里，我们比较了来自北方红海的普遍存在的石珊瑚Stylophora pistillata对急性（7小时）和慢性（7-11天）热应力事件的反应，包括27摄氏度的温度处理（即，（当地最高月平均值）、29.5摄氏度、32摄氏度和34.5摄氏度，并评估珊瑚在暴露后的恢复情况。总的来说，S。雌蕊对急性和慢性热胁迫的反应非常相似，主要对温度处理而不是持续时间或加热速率作出反应。此外，珊瑚显示出极高的耐热性，在宿主在34.5摄氏度发生快速组织坏死和死亡之前，在32摄氏度以下保持其生理性能，藻类共生体或叶绿素a几乎没有损失。虽然在生理反应度量中存在一些可变性，但光合效率测量（即，最大量子产率（Fv/Fm）准确地反映了整体生理反应模式，这些测量用于产生Fv/Fm有效剂量（ED 50）度量，作为珊瑚耐热性的代表。这种方法产生了类似的ED 50值的急性和慢性实验（34.47摄氏度对33.81摄氏度），突出了急性热分析的潜力与Fv/Fm的测量作为一个系统和标准化的方法，定量比较上限的热量限制造礁珊瑚使用便携式实验系统。
Global warming is resulting in unprecedented levels of coral mortality due to mass bleaching events and, more recently, marine heatwaves, where rapid increases in seawater temperature cause mortality within days. Here, we compare the response of a ubiquitous scleractinian coral, Stylophora pistillata, from the northern Red Sea to acute (7 h) and chronic (7-11 d) thermal stress events that include temperature treatments of 27 degrees C (i.e., the local maximum monthly mean), 29.5 degrees C, 32 degrees C, and 34.5 degrees C, and assess recovery of the corals following exposure. Overall, S. pistillata exhibited remarkably similar responses to acute and chronic thermal stress, responding primarily to the temperature treatment rather than duration or heating rate. Additionally, corals displayed an exceptionally high thermal tolerance, maintaining their physiological performance and suffering little to no loss of algal symbionts or chlorophyll a up to 32 degrees C, before the host suffered from rapid tissue necrosis and mortality at 34.5 degrees C. While there was some variability in physiological response metrics, photosynthetic efficiency measurements (i.e., maximum quantum yield Fv/Fm) accurately reflected the overall physiological response patterns, with these measurements used to produce the Fv/Fm effective dose (ED50) metric as a proxy for the thermal tolerance of corals. This approach produced similar ED50 values for the acute and chronic experiments (34.47 degrees C vs. 33.81 degrees C), highlighting the potential for acute thermal assays with measurements of Fv/Fm as a systematic and standardized approach to quantitively compare the upper thermal limits of reef-building corals using a portable experimental system.