Upper-mesophotic and shallow reef corals exhibit similar thermal tolerance, sensitivity and optima
Upper-mesophotic and shallow reef corals exhibit similar thermal tolerance, sensitivity and optima
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DOI：
10.1007/s00338-021-02095-w
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发表时间：
2021-04-19
期刊：
影响因子：
3.5
通讯作者：
Goodbody-Gringley, Gretchen
中科院分区：
文献类型：
--
作者：
Gould, Katelyn;Bruno, John F.;Goodbody-Gringley, Gretchen
生活在海洋环境中的外温动物的生理受到其局部热经验的强烈影响。随着全球海洋热浪的增加，生活在其最佳温度附近的硬珊瑚越来越容易受到漂白和死亡的影响。30 m深度以下的中光珊瑚生态系统（MCE）的特点是比邻近的浅水珊瑚礁温度低，根据理论，这应该会导致不同深度之间对温度的代谢反应不同。人们对当地温度如何影响中光珊瑚的生理反应知之甚少。我们比较了四种珊瑚的温度敏感性之间的浅（5-10米）和上层mesophotic（30-35米）在百慕大的珊瑚礁。在实验室围隔中测量了四种常见珊瑚（Diploria despithiformis、Orbicella franksi、Montastraea cavernosa和Porites astreoides）在宽温度范围（19-36 ℃）内的热性能曲线（TPC）。结果表明，最大总光合速率（GP-P-max）和平均总光合速率（GP-lnc）在不同树种间差异显著。相比之下，热敏感性（P-max，T-opt，lnc，E，Eh或Th）没有变化的深度之间的同种除了失活能量（GP-Eh）在D。形。此外，总呼吸（R）没有不同的物种或深度之间的任何热度量。不同深度之间类似的代谢反应表明，对不同热条件的局部适应和/或驯化可能不会发生。相反，上层中光珊瑚在百慕大没有较低的漂白阈值比浅水同种，但类似的热敏感性支持MCE的功能作为一个热避难所的潜力。
The physiology of ectotherms living in marine environments is strongly influenced by their local thermal experience. Scleractinian corals living near their thermal optimums are increasingly vulnerable to bleaching and mortality as oceanic heat waves increase globally. Mesophotic coral ecosystems (MCEs) below 30 m depths are characteristically cooler than adjacent shallow water reefs, which according to theory should result in differential metabolic responses to temperature between depths. How local temperatures influence physiological responses in mesophotic corals is poorly understood. We compared thermal sensitivities of four coral species between a shallow (5-10 m) and upper-mesophotic (30-35 m) reef in Bermuda. Thermal performance curves (TPC) were measured in laboratory mesocosms for four common coral species (Diploria labyrinthiformis, Orbicella franksi, Montastraea cavernosa andPorites astreoides) across a wide range of temperatures (19-36). Our results indicate that the maximum rate of gross photosynthetic (GP) performance (GP-P-max) and the mean overall photosynthetic rates (GP-lnc) varied significantly among species. In contrast, thermal sensitivity (P-max, T-opt, lnc, E, Eh, or Th) did not vary between depths for conspecifics except for deactivation energy (GP-Eh) in D. labyrinthiformis. Additionally, gross respiration (R) did not differ among species or between depths for any thermal metric. Similar metabolic responses between depths suggest that local adaptation and/or acclimatization to different thermal conditions is likely not occurring. Instead, upper-mesophotic corals in Bermuda do not have lower bleaching thresholds than shallow water conspecifics, but similar thermal sensitivities supporting the potential for MCEs to function as a thermal refuge.