RAPID collaborative proposal: Will corals recover from bleaching under ocean acidification conditions?

2014年10月，夏威夷群岛附近的水温达到了30°C，这是自20世纪40年代以来有记录以来第二热的月份。比正常温度高出2摄氏度的结果是，夏威夷群岛发生了严重的白化事件。在卡内奥赫湾，75%的优势珊瑚物种都被漂白了。白化是珊瑚失去共生藻类而变白的一种应激反应。长时间的白化会导致疾病，减少珊瑚的生长和繁殖，甚至死亡。此外，大气中二氧化碳含量的上升导致海洋变得更酸，可能不适合珊瑚礁生存。预计到本世纪末，海水的酸性将是现在的两倍。目前夏威夷的白化事件提供了一个难得的机会，可以测试珊瑚在本世纪末预计会出现的酸性海洋条件下的恢复能力。这项研究比较了在正常海水中漂白珊瑚和在酸性海水中漂白珊瑚的恢复速度。研究结果将告知哪些物种或珊瑚礁区域对全球变化的适应能力更强，从而成为更好的保护目标。研究结果将与帕帕哈瑙莫库阿基亚海洋国家纪念碑和世界遗产的管理特别相关。它还将为预测未来珊瑚礁持久性的模型提供关键的数据输入。在教育方面，该研究将为学生和博士后研究人员提供一个动态的学习和培训环境。少数民族学生将被招募并接受海洋科学方面的培训，为他们提供STEM学科的优秀职业选择。结果将通过出版物、课堂访问、公众宣传和在线媒体广泛传播。珊瑚礁是地球上最多样化的生态系统之一，约有25%的海洋物种栖息于此。大规模的珊瑚白化对珊瑚礁栖息地的完整性构成了重大威胁，预计在未来气候模式情景下，这将是珊瑚礁死亡的主要原因。尽管之前关于珊瑚从白化中恢复的工作为该项目奠定了基础，但气候变化和海洋酸化对珊瑚从白化中恢复的影响仍有待观察。该项目利用了夏威夷Kaneohe湾和Waimanalo湾之间基线温度和海水酸度条件的自然差异。这两个地点都受到了大规模白化事件的影响。本研究将测试在正常海水中漂白的珊瑚与在酸性较强海水中漂白的珊瑚的复原率。将解决三个问题：1)海洋酸化是否会减慢白化的恢复速度？2)浮游动物的摄食是否会减少白化的影响？3)适应了更温暖、更酸的环境（卡内奥河湾）的珊瑚是否比目前平均海洋环境（怀马纳洛湾）的珊瑚恢复得更快？该项目整合了生态学、生理学、进化学和基因组学等学科的技术。这项研究将有助于确定弹性珊瑚物种或种群的特征，这些物种或种群更有可能在未来的白化事件中幸存下来。

Following the second hottest month on record since the 1940s, water temperatures near the main Hawaiian Islands reached 30 °C in October 2014. The result of this 2 °C increase above normal temperatures has been a severe bleaching event across the Hawaiian Archipelago. In Kaneohe Bay, 75% of the dominant coral species are bleached. Bleaching is a stress response whereby corals lose their symbiotic algae and turn white. Prolonged bleaching can lead to disease, decreases in coral growth and reproduction, and even death. In addition, rising atmospheric levels of carbon dioxide cause the oceans to become more acidic and potentially less hospitable to coral reefs. By the end of this century, seawater is predicted to be twice as acidic as it is today. The current bleaching event in Hawaii provides a rare opportunity to test the ability of corals to recover under the acidic ocean conditions expected by the end of this century. This research compares the recovery rate of bleached corals in normal seawater to those exposed to more acidic seawater. The results will inform which species or reef regions are more resilient to global change conditions and thus better targets for protection. The results will be particularly relevant to management of the Papahanaumokuakea Marine National Monument and World Heritage site. It will also provide critical data input for models that project the persistence of reefs in the future. Educationally, the research will provide a dynamic learning and training environment for students and a post-doctoral researcher. Minority students will be recruited and trained in marine science providing them with excellent career options in STEM disciplines. Results will be broadly disseminated through publications, classroom visits, public outreach and online media. Coral reefs are among the most diverse ecosystems on the planet, housing an estimated 25% of marine species. Massive coral bleaching poses a substantial threat to the integrity of coral reef habitats, and is predicted to be the major source of mortality for reefs under future climate model scenarios. Although previous work on the recovery of corals from bleaching sets the groundwork for this project, it remains to be seen how recovery from bleaching will be impacted by climate change and ocean acidification. This project takes advantage of the natural difference in baseline temperature and seawater acidity conditions between Kaneohe Bay and Waimanalo Bay, HI. Both these sites are impacted by the massive bleaching event. This research will test the recovery rate of bleached corals in normal seawater to that of bleached corals exposed to more acidic seawater. Three questions will be addressed: 1) Will ocean acidification slow rates of recovery from bleaching?; 2) Does zooplankton feeding minimize the impact of bleaching?; and 3) Do corals acclimated to warmer, more acidic conditions (Kaneohe Bay) recover more quickly than corals at present day mean oceanic conditions (Waimanalo Bay)? The project integrates techniques across the disciplines of ecology, physiology, evolution, and genomics. The research will help to identify characteristics of resilient coral species or populations that are more likely to survive bleaching events in the future.