RAPID: Coral reproduction following mass corallivore outbreak and offspring tolerance during El Nino modulates reef recovery

自然和人为影响日益并存，对海洋系统，特别是珊瑚礁产生负面影响。自然捕食者的爆发，如食珊瑚的海星之冠，可以迅速杀死珊瑚。此外，气候和海洋变暖产生的压力正在推动珊瑚漂白，或珊瑚与甲藻营养共生的破坏，这可能导致珊瑚饥饿和大规模死亡。法属波利尼西亚莫雷亚岛的珊瑚礁目前正经历着海星之冠的爆发，珊瑚死亡率很高。与此同时，目前的厄尔尼诺变暖正在推高海洋温度，有可能加剧珊瑚的季节性热应力高峰。特别是，在莫雷亚主要建造珊瑚礁的Pocillopora spp，正优先被荆棘之冠的海星吃掉，并且历史上在最温暖的月份表现出珊瑚漂白。鉴于珊瑚对莫雷亚岛前礁上生态优势的Pocillopora spp的快速和广泛的捕食以及复合厄尔尼诺热应激，本项目研究了泻湖礁Pocillopora spp的繁殖、补充和耐温在珊瑚礁恢复中的作用。这项工作提供了量化特定物种繁殖和耐热性的能力，以更好地了解和预测对珊瑚礁恢复和复原力的遗留影响。该项目的更广泛影响包括对早期职业科学家培训的研究支持，以及为法属波利尼西亚和罗德岛的学校的本科生和高中生课程模块和研究项目提供的数据和材料。该项目是对珊瑚暴发和热应力等多种同时发生的扰动事件对珊瑚礁的影响的迫切需要的评估。在量化角冠海星丰度和分布的同时，研究人员正在完成对环礁湖成体和幼体Pocillopora spp的多样性和丰度的遗传和生态特征描述，以确定产卵和热峰之前的种群，量化Pocillopora spp的繁殖和幼虫的耐热性，并确定季节性热应激高峰期和厄尔尼诺年几个月后的泻湖和前礁的Pocillopora spp的密度和热耐力。这些结果促进了人们对自然干扰后珊瑚产卵和补充的后果的理解。重要的是，该项目提供了信息，说明在敏感的早期生命阶段，优势种Pocillopora spp是如何应对海洋变暖和海洋热浪的慢性和急性压力的。该项目的结果有助于更深入地了解压力对具有生态、经济和文化意义的珊瑚礁生态系统的影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Natural and anthropogenic impacts are increasingly co-occurring with negative consequences for marine systems, specifically coral reefs. Natural predator outbreaks, such as the corallivorous Crown of Thorns Sea stars, can rapidly kill corals. Further, the stress generated by climate and ocean warming is driving coral bleaching, or the breakdown of the coral-dinoflagellate nutritional symbiosis, which can cause coral starvation and mass mortality. The reefs of Mo’orea, French Polynesia, are currently experiencing an outbreak of Crown of Thorns sea stars, with high coral mortality. In conjunction, the current El Niño warming is driving up ocean temperatures, with the potential to exacerbate peak seasonal thermal stress on corals. In particular, Pocillopora spp, which are dominant reef builders in Mo’orea, are being preferentially eaten by Crown of Thorns Sea stars and have historically displayed coral bleaching during the warmest months. In light of the rapid and extensive coral predation on the ecologically dominant Pocillopora spp on the forereef in Mo’orea and compounding El Niño thermal stress, this project examines the role of lagoon reef Pocillopora spp reproduction, recruitment, and temperature tolerance in reef recovery. This work provides the capacity to quantify species-specific reproduction and thermal tolerance to better understand and forecast legacy effects on reef recovery and resilience. Broader impacts of this project include research support for early career scientist training, as well as data and materials for undergraduate and high school student curriculum modules and research projects for schools in French Polynesia and Rhode Island. This project represents an urgently needed assessment of the impact of multiple co-occurring disturbance events of corallivore outbreaks and thermal stress on coral reefs. Along with quantifying the Crown of Thorns Sea star abundance and distribution, researchers are completing a genetic and ecological characterization of the diversity and abundance of adult and juvenile Pocillopora spp in the lagoon to determine the population prior to spawning and thermal peak, quantifying reproduction of Pocillopora spp and larval thermal tolerance, and determining the density and thermal tolerance of Pocillopora spp recruits in the lagoon and forereef during the peak of seasonal thermal stress and several months after, in an El Niño year. The results advance understanding of the consequences of coral spawning and recruitment immediately following a natural disturbance. Importantly, the project provides information on how the dominant Pocillopora spp are contending with the chronic and acute stress of ocean warming and marine heat waves at sensitive early life stages. The results of this project provide a deeper understanding of the legacy of stress on the ecologically, economically, and culturally significant coral reef ecosystem.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.