Phenotype and genotype of coral adaptation and acclimatization to global change

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。全球气候模型预测，到本世纪末，热带海水的温度将比现在高出3摄氏度，酸度至少是现在的两倍，这将威胁到珊瑚礁生态系统的长期生存。气温升高和海洋酸化已被证明会导致珊瑚生长速度下降，珊瑚疾病和死亡率增加。迄今为止，人们的假设是珊瑚将无法适应，因为人为造成的海洋酸化和气候变化的速度太高。本研究旨在测量珊瑚的生理变化，以确定珊瑚是否适应或适应全球变化。如果它们能适应，适应的速度有多快？不同物种和地理位置的适应率有何不同？这些问题的答案是制定策略性珊瑚保育和管理计划的关键。为了解决这些问题，我们将采用两部分的方法对8种夏威夷珊瑚进行研究：1)对在自然温度和酸度梯度下发现的天然珊瑚进行调查；2)进行为期两年的中生态研究，将第一部分收集的珊瑚暴露在预计在本世纪末的温度和酸度条件下。这项工作对于保护夏威夷被联合国教科文组织列为世界遗产的帕帕哈瑙莫库亚克海洋国家纪念碑（PMNM）的珊瑚生物多样性尤为重要。PMNM包括夏威夷群岛的西北部，是地球上最原始和受到高度保护的珊瑚礁之一，也是世界上最大的海洋保护区之一。这项研究还将为用于预测未来珊瑚礁持久性的模型提供关键数据输入。这项工作的发现将通过科学会议、同行评议的期刊出版物、新闻稿、公开讲座、网站平台和课堂教学进行交流。该项目将培养未来的科学家（1名博士生、3名本科生和2名高中生），并提供一个培养他们追求科学职业选择所需的激情和技能的环境。因此，这项工作有可能改变我们对珊瑚如何应对快速环境变化的概念和经验理解，并对珊瑚保护工作和教育产生影响。这项研究将测试珊瑚无法适应的假设，因为人为造成的海洋酸化和气候变化的速度太高。研究人员将定量测量珊瑚的生理变化，以确定珊瑚是否适应或适应全球变化。简而言之，本研究建议采用两部分方法评估8种夏威夷珊瑚对长期暴露于高温和海洋酸化（OA）条件下的适应和驯化能力：1)对自然温度和二氧化碳分压梯度下发现的天然珊瑚进行调查；2)对第一部分中收集的珊瑚进行为期两年的中生态研究，以适应本世纪预计的温度和二氧化碳分压条件。在这两种方法中，研究人员将结合同一种珊瑚的基因型（即基因组和转录组）反应来测量珊瑚对未来气候变化的表型（即生理和生物地球化学）反应。这项研究将在种群和物种水平上解决变异问题。它也将是第一个利用一套全面的生理、生物地球化学和基因组工具，在多年的时间框架内检查温度升高和二氧化碳分压对复制中生态系统中珊瑚的影响的研究。拟议的研究包括夏威夷群岛约97%的珊瑚物种，为研究提供了广泛的空间和生物学相关性。

Coral reefs are among the most diverse ecosystems on the planet, housing an estimated 25% of marine species. Global climate models predict that by the end of this century, tropical seawater temperatures will be up to 3°C warmer than they are today and at least twice as acidic, which threatens the long-term survival of coral reef ecosystems. Elevated temperature and ocean acidification have been shown to cause reduced coral growth rates and increased coral disease and mortality rates. To date, the assumption has been that corals will not be able to adapt because the rates of anthropogenically driven ocean acidification and climate change are too high. This study aims to measure changes in coral physiology to determine if coral adapt or acclimatize to global change. If they can adapt, how fast is the adaptation rate? How do adaptation rates differ among species and geographic locations? Answers to these questions are key to developing strategic coral conservation and management plans. To address these questions, eight species of Hawaiian corals will be studied using a two-part approach: 1) a survey of natural corals found across natural temperature and acidity gradients and 2) a two-year mesocosm study which will expose corals collected in part 1 to temperature and acidity conditions expected at the end of this century. This work is especially important in Hawaii for preserving coral biodiversity in a UNESCO World Heritage Site - the Papahanaumokuakea Marine National Monument (PMNM). PMNM encompasses the northwestern Hawaiian Islands, is renowned as one of the most pristine and highly protected coral reefs remaining on the planet, and is one of the largest marine conservation areas in the world. This research will also provide critical data input for models used to project the persistence of reefs in the future. Findings from this work will be communicated at scientific meetings, through peer-reviewed journal publications, and via press releases, public lectures, website platforms, and classroom teaching. This project will train future scientists (one PhD student, 3 undergraduates, and 2 high school students) and provide an environment that will foster their passion and skills necessary to pursue career options in science. Thus, this work has the potential to transform our conceptual and empirical understanding of how corals respond to rapid environmental change and make an impact on coral conservation efforts and education.This study will test the assumption that corals will not be able to adapt because the rates of anthropogenically driven ocean acidification and climate change are too high. The investigators will quantitatively measure changes in coral physiology to determine if coral adapt or acclimatize to global change. In brief, this study proposes to evaluate the adaptation and acclimatization capacity of eight species of Hawaiian corals to long-term exposure of elevated temperature and ocean acidification (OA) conditions using a two-part approach: 1) a survey of natural corals found across natural temperature and pCO2 gradients and 2) a two-year mesocosm study where corals collected in part 1 to a range of temperature and pCO2 conditions expected this century. In both approaches, the phenotypic (i.e., physiological and biogeochemical) responses of corals to future climate change will be measured by the investigator in conjunction with the genotypic (i.e., genomic and transcriptomic) responses of the same corals. This study will address variation at both the population and species level. It will also be the first study to examine the effects of elevated temperature and pCO2 on corals in replicated mesocosms over a multiannual timeframe with a comprehensive suite of physiological, biogeochemical, and genomic tools. The proposed study includes ~97% of the coral species in the Hawaiian archipelago, yielding extensive spatial and biological relevance for the study.