Reactions of juvenile coral to three years of consecutive thermal stress
Reactions of juvenile coral to three years of consecutive thermal stress
复制标题
幼珊瑚对连续三年热应激的反应
DOI：
10.1016/j.scitotenv.2022.161227
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发表时间：
2023
影响因子：
9.8
通讯作者：
Harii Saki
中科院分区：
文献类型：
--
作者：
Hazraty-Kari Sanaz;Morita Masaya;Tavakoli-Kolour Parviz;Nakamura Takashi;Harii Saki
随着全球气温的持续上升，珊瑚在其生命的早期阶段都面临着越来越大的热压力；然而，人们对这一现象的影响知之甚少。我们在连续三年的时间里，每年将造礁珊瑚acropora tenuis幼崽暴露在~ 26-28°C（对照）和~ 31°C（热应激）中一周。在热胁迫的第一年，尽管共生藻密度在幼珊瑚中下降，但仍有大约96%的幼珊瑚存活下来。相比之下，热应激的第三年存活率下降到50%。应激组应激后在自然条件下的存活率也逐渐下降。在连续热应激组（两年内两次应激）中，存活率降低率显著。共生藻密度和光合活性（Fv/Fm）在应激组也呈下降趋势。热应激对幼鱼的生长影响不显著。在热胁迫的第三年，温度对幼鱼的存活、亮度（白化指标）、共生藻密度和光合效率产生负面影响。连续几年的压力似乎会导致幼珊瑚的存活率下降，三年的压力会导致珊瑚礁的严重衰退。总之,一个。幼体不能适应热应激，夏季连续的<7天的热浪可能会对其恢复能力产生负面影响。
As global temperatures continue to rise, corals are being exposed to increasing heat stress throughout their early life stages; however, the impact of this phenomenon is poorly understood. We exposed the reef-building coralAcropora tenuisjuveniles to ∼26–28 °C (control) and ∼ 31 °C (heat stress) for one week per year over three consecutive years. In the first year of heat stress, >96 % of juveniles survived despite symbiotic algal densities in juvenile corals declining. In comparison, survival rates in the third year of heat stress declined to 50 %. Survival rates under natural conditions after stress also gradually decreased in the stressed groups. The rate in the reduction of survivorship was prominent in the consecutive thermally stressed groups (juveniles stressed twice in two years). Symbiotic algal density and photosynthetic activity (Fv/Fm) also declined in stressed juvenile groups. However, heat stress did not significantly affect the growth of juveniles. In the third year of heat stress, temperature negatively affected the physiology of juveniles in terms of survivorship, brightness (an indicator of bleaching), symbiotic algal density, and photosynthetic efficiency. Stress across consecutive years appeared to cause the survivorship of juvenile corals to decline, with three years of stress contributing to the severe decline of a reef. In conclusion,A. tenuisjuveniles are not able to acclimatize to heat stress, with successive heat waves of <7 days in the summer potentially negatively affecting resilience.