CAREER: Helping or hindering? Determining the influence of repetitive marine heatwaves on acclimatization of reef-building corals across biological scales

事业：帮助还是阻碍？

• 批准号: 2237658
• 负责人: Katie Barott
• 金额: $ 121.05万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-15 至 2028-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2237658&HistoricalAwards=false
• 关键词: CAREER; Helping; hindering; Determining; influence

Ocean warming driven by climate change has led to staggering losses of coral on reefs worldwide and is now among the most pressing of stressors threatening the survival of coral reef ecosystems today. As marine heatwaves associated with ocean warming become increasingly frequent, it is urgent to understand if and how reef-building corals will be able to respond to these repeat stress events and thus survive in a rapidly warming ocean. To address this problem, this project is investigating how corals on the reef respond to recurring marine heatwaves in order to identify if repeat exposure to heat stress promotes coral tolerance of higher temperatures via acclimatization or instead leads to the accumulation of stress and thus reduced performance and survival following future stress. The results of this study are critical for understanding how the current generation of corals will respond to increasingly warmer oceans, and whether acclimatization will buy enough individuals sufficient time for adaptation to occur and promote coral persistence into the future. In addition, this project is training students from secondary schools through advanced postdoctoral researchers in global change biology and ecology. Specifically, the investigators are increasing access to research opportunities for undergraduate students by developing a new hands-on course-based undergraduate research experience (CURE) in Global Ocean Change Biology that will reach hundreds of students per year. Outreach efforts are also being developed to increase the participation and retention of historically disenfranchised students in marine science, and include creation of hands-on coral reefs and climate change activities for incoming first-generation, low-income undergraduate students and a professional development program to train middle and high-school teachers to deploy these climate change activities in their classrooms in the Philadelphia Public School District, which serves a predominantly low-income Black and Latinx student body. Acclimatization following exposure to sub-lethal heat stress may be an important protective mechanism for corals to survive a changing climate. However, the role of environmental memory of marine heatwaves in driving acclimatization or, conversely, stress accumulation and sensitization of reef-building corals is not well understood. This study is addressing this question using a combination of in situ and mesocosm experiments to assess the cellular, organismal, and ecological consequences of repeat heatwaves on corals with contrasting bleaching histories. Specifically, the researchers are monitoring adjacent conspecific pairs of bleaching-susceptible and bleaching-resistant individuals of two reef-building coral species in Hawaii, Montipora capitata and Porites compressa. These corals have been monitored for over 7 years through multiple bleaching events and are being used to test the hypothesis that environmental memory of marine heatwaves differentially alters coral thermal performance due to phenotypic variation in acclimatization ability within and between species. This work is identifying whether the bleaching thresholds of corals with different bleaching histories varies through time, and the consequences of these phenotypes on coral calcification, survival, and population size structure are being assessed using a combination of benthic surveys, photogrammetry, and in situ growth measurements. The influence of environmental memory of heatwaves on coral physiology is being assessed using thermal performance curves to determine how the thermal optima of respiration, photosynthesis, calcification, and host intracellular pH change (or not) over time (e.g. ambient vs. heatwave years) and if that response differs between corals with contrasting bleaching phenotypes. Finally, the contribution of algal endosymbionts to acclimatization is being evaluated by exposing corals to a range of increasing temperatures in experimental mesocosms, potentially uncovering differences in the degree of acclimatization or sensitization for host vs. symbiont traits in corals with high fidelity (P. compressa) vs. cosmopolitan (M. capitata) symbiont associations. By understanding of the phenotypic diversity in thermal performance across biological scales, this research improves predictions of coral persistence in the face of the ongoing climate crisis.This project is supported by the Biological Oceanography, Integrative Ecological Physiology, and Ocean Education Programs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

由气候变化驱动的海洋变暖导致了全球珊瑚礁上珊瑚的惊人损失，现在是威胁当今珊瑚礁生态系统生存的压力源中最紧迫的损失。随着与海洋变暖相关的海洋热浪变得越来越频繁，迫切要了解珊瑚礁是否能够应对这些重复的压力事件，从而在快速变暖的海洋中生存。为了解决这个问题，该项目正在研究珊瑚礁上的珊瑚如何应对反复出现的海洋热浪，以确定反复暴露于热应激是否会通过适应性促进较高温度的珊瑚耐受性，或者导致压力的积累，从而降低表现和未来压力后的性能和生存。这项研究的结果对于了解当前一代的珊瑚将如何应对越来越温暖的海洋，以及适应性是否会购买足够的个人进行适应并促进未来的珊瑚持久性。此外，该项目是通过全球变化生物学和生态学的高级博士后研究人员培训中学的学生。具体来说，研究人员正在通过开发全球海洋变化生物学的新的基于动手课程的本科研究经验（CURE）来增加本科生的研究机会，每年将吸引数百名学生。还正在开发外展工作，以增加历史上删除的学生参与和保留海洋科学的参与和保留，并包括创建动手的珊瑚礁和气候变化活动，以供第一代学生，低收入的学生和专业发展计划以及一项专业发展计划，以培训中学和高中培训这些在教学室中的培训中的较低的教室，以培训他们在课堂上的较低层次的活动。拉丁裔学生团体。暴露于亚致死性热应激后的适应性可能是珊瑚生存气候变化的重要保护机制。但是，尚不清楚海洋热浪环境记忆在驱动适应性或珊瑚礁建造珊瑚的压力积累和敏感性方面的作用。这项研究是通过原位和中cosm实验的组合来解决这个问题，以评估重复热浪在珊瑚上的细胞，生物和生态后果，并具有对比鲜明的漂白史。具体而言，研究人员正在监视夏威夷两个礁石建造珊瑚种类的邻近的相邻易敏感和抗漂白的个体对，蒙蒂波拉大厦和porites Compressa。通过多次漂白事件对这些珊瑚进行了7年的监测，并用于检验以下假设：由于物种内部和物种之间适应能力的表型变化，海洋热浪的环境记忆会差异改变珊瑚的热性能。这项工作正在确定具有不同漂白史的珊瑚的漂白阈值随着时间的流逝而变化，以及这些表型对珊瑚钙化，生存和种群大小结构的后果是否正在使用底栖调查，摄影测量和现场生长测量的组合来评估。正在使用热性能曲线评估热浪的环境记忆对珊瑚生理的影响，以确定呼吸，光合作用，钙化和宿主的细胞内pH变化（或不随着时间的流逝）的影响（例如，环境与热浪年）如何变化，以及在珊瑚之间的反应与对比造成鲜明的侵蚀性的被侵蚀性的响应是否不同。最后，正在通过将珊瑚暴露于实验性中验中的一系列温度来评估藻类内共生体对适应的贡献，从而可能发现与高富达（P. compressa）vs. cosmopolitation（M. cosmopolitations vs. symbiont cosiiation vs. symbiont特征）的适应性或敏感性的差异。通过了解生物学量表的热性能中的表型多样性，这项研究改善了面对正在进行的气候危机的珊瑚持续性的预测。该项目得到了生物海洋学，综合生态生理学和海洋教育计划的支持，这项奖项是通过评估NSF的Insprient Intellial Infectiria and Intellial and Intellial and Intellial and Internial and Intellial and Intellial的奖励。