Coral reefs are one of the most susceptible ecosystems to ocean acidification (OA) caused by increasing atmospheric carbon dioxide (CO2). OA is suspected to impact the calcification rate of corals as well as multiple early life stages including larval and settlement stages. Meanwhile, there is now a strong interest in evaluating if organisms have the potential for acclimatization or adaptation to OA. Here, by taking advantage of a naturally acidified site in Nikko Bay, Palau where corals are presumably exposed to high CO2 conditions for their entire life history, we tested if adult and the next-generation larvae of the brooder coral Pocillopora acuta originating from the high-CO2 site are more tolerant to high CO2 conditions compared to the individuals from a control site. Larvae released from adults collected from the high-CO2 site within the bay and a control site outside the bay were reciprocally cultivated under experimental control or high-CO2 seawater conditions to evaluate their physiology. Additionally, reciprocal transplantation of adult P. acuta corals were conducted between the high-CO2 and control sites in the field. The larvae originating from the control site showed lower Chlorophyll-a content and lipid percentages when reared under high-CO2 compared to control seawater conditions, while larvae originating from the high-CO2 site did not. Additionally, all 10 individuals of adult P. acuta from control site died when transplanted within the bay, while all P. acuta corals within the bay survived at both control and high-CO2 site. Furthermore, P. acuta within the bay showed higher calcification and net photosynthesis rates when exposed to the condition they originated from. These results are one of the first results that indicate the possibility that the long-living corals could enable to show local adaptation to different environmental conditions including high seawater pCO2.

中文翻译：

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来自自然酸化栖息地的成虫和转基因珊瑚幼虫的潜在适应和适应反应

珊瑚礁是最容易受到由增加的大气二氧化碳 (CO2) 引起的海洋酸化 (OA) 影响的生态系统之一。OA 被怀疑会影响珊瑚的钙化率以及包括幼虫和定居阶段在内的多个早期生命阶段。同时，现在人们对评估生物体是否具有适应或适应 OA 的潜力产生了浓厚的兴趣。在这里，通过利用帕劳日光湾的一个自然酸化地点，珊瑚可能在其整个生命史中都暴露在高二氧化碳条件下，我们测试了来自高海拔地区的育雏珊瑚 Pocillopora acuta 的成虫和下一代幼虫。 - 与来自对照站点的个体相比，CO2 站点对高 CO2 条件的耐受性更高。从海湾内的高 CO2 站点和海湾外的控制站点收集的成虫释放的幼虫在实验控制或高 CO2 海水条件下相互培养，以评估其生理学。此外，在野外高二氧化碳和对照地点之间进行了成年 P. acuta 珊瑚的相互移植。与对照海水条件相比，来自对照地点的幼虫在高 CO2 条件下饲养时显示出较低的叶绿素 a 含量和脂质百分比，而来自高 CO2 地点的幼虫则没有。此外，当移植到海湾内时，来自对照地点的所有 10 只 P. acuta 成年 P. acuta 珊瑚都死亡，而海湾内的所有 P. acuta 珊瑚在对照和高 CO2 地点都存活下来。此外，P. 当暴露于它们起源的条件时，海湾内的 acuta 显示出更高的钙化和净光合作用速率。这些结果是最早表明长寿珊瑚可能能够对不同环境条件（包括高海水 pCO2）表现出局部适应能力的结果之一。