RAPID- The implications of El Nino-related bleaching on coral recruitment in Moorea

这项研究探讨了2015-16厄尔尼诺对法属波利尼西亚珊瑚礁的影响，美国国家科学基金会支持该地区的长期生态研究。 厄尔尼诺现象给太平洋带来了各种不寻常的情况，但对珊瑚礁来说，最重要的影响是夏季海水变暖造成的。 漂白是导致珊瑚失去颜色和死亡的过程，是厄尔尼诺现象对珊瑚礁产生负面影响的一个戏剧性例子，但高温也通过损害生殖和婴儿珊瑚的不良招募产生潜在影响。 因此，厄尔尼诺现象很可能与珊瑚礁在受到干扰后再生能力下降有关，有可能妨碍珊瑚礁的全面恢复，或有利于珊瑚礁群落的重大变化。 这项研究建立在莫雷阿岛LTER调查的无与伦比的历史基础上，以了解厄尔尼诺现象如何影响珊瑚的补充，如到达珊瑚礁的婴儿珊瑚数量，生长的婴儿珊瑚数量以及由于这些事件而发展的社区类型。 该研究涉及教师和研究生在莫雷阿进行的实地考察，在此期间，将安装定居瓷砖并监测婴儿珊瑚，评估婴儿珊瑚的整体“健康”，并将量化天然和人工礁表面以促进社区发展。 这项研究的结果将有助于了解海洋生态系统如何应对自然和人类相关的干扰，包括全球气候变化，并将提高能力，以了解美国沃茨和世界各地的珊瑚礁将以何种形式在未来世纪生存。该项目为研究生创造了独特的机会，在国际背景下工作，在那里他们将进行研究，促进STEM职业生涯，欣赏不同的热带生态系统，以及气候变化在改变生态系统动态中的作用。 该项目的更广泛的影响将通过将结果纳入当地高中的生命科学课程来加强，部分是通过在加州州立大学北岭研究生的课堂练习中使用莫雷阿的定居瓷砖。该项目解决了2015-16厄尔尼诺对法属波利尼西亚莫雷阿珊瑚补充的影响，自2005年以来，人们一直在研究莫雷阿珊瑚礁LTER。 该计划支持的时间序列研究提供了一个独特的历史背景，可以衡量即将到来的厄尔尼诺现象的生态影响。 由于珊瑚白化对珊瑚繁殖产生负面影响，而以往的厄尔尼诺事件与全球珊瑚补充量下降有关，因此可以合理地假设，莫雷阿岛的珊瑚补充量将发生变化（即，密度下降）和类型（即，分类组成）在明年。 这些可能性具有重要的影响，因为珊瑚补充介导了社区对干扰的恢复能力，并调节了未来珊瑚礁发展的轨迹。 在这个为期12个月的项目中，将进行一系列测定和操作实验，以解决四个假设：（1）厄尔尼诺相关海水变暖将抑制珊瑚补充，（2）变暖将影响珊瑚定居后的成功，（3）对Pocillopora而言，对珊瑚补充的影响将通过密度依赖性过程进行调节，及（4）由此产生的补充扰动将改变珊瑚群落发展的轨迹。 这项研究的结果将普遍适用于揭示决定珊瑚礁群落对厄尔尼诺现象等周期性脉冲扰动作出反应的人口过程。

This research explores the effects of the 2015-16 El-Niño on coral reefs in French Polynesia where the US National Science Foundation supports a Long-Term Ecological Research site. El Niño brings a diversity of unusual conditions to the Pacific Ocean, but for coral reefs the most important effect is caused by seawater warming during the summer. Bleaching, the process causing corals to lose color and die, is a dramatic example of the negative effects of El Niño on reef corals, but high temperature also has insidious effects through impaired reproduction and poor recruitment of baby corals. As a result, El Niño conditions are likely to be associated with a degraded ability of coral reefs to regrow following disturbances, potentially preventing a full recovery, or favoring substantial changes in the community that develops. This research builds on the unrivalled history of LTER investigations in Moorea to ask how coral recruitment is affected by El Niño, as measured by the number of baby corals arriving to the reef, the number of baby corals that grow, and the kinds of communities that develop as a result of these events. The study involves fieldwork conducted in Moorea by faculty and graduate students, during which settlement tiles will be installed and monitored for baby corals, baby corals will be evaluated for overall "health", and natural and artificial reef surfaces will be quantified for community development. The results of this study will help to understand how marine ecosystems are responding to the spectrum of natural and human-related disturbances to which they exposed, including global climate change, and will improve the capacity to understand in what form coral reefs in US waters and throughout the world will survive the coming century. The project creates unique opportunities for graduate students to work in an international context, where they will conduct research promoting STEM careers, an appreciation of diverse tropical ecosystems, and the role of climate change in modifying ecosystem dynamics. The broader implications of this project will be strengthened by integrating the results into life science curricula at local high schools, in part by utilizing settlement tiles from Moorea in classroom exercises staffed by California State University Northridge graduate students.This project addresses the effects of the 2015-16 El-Niño on coral recruitment in Moorea, French Polynesia, where coral reefs have been studied since 2005 thought the Moorea Coral Reef LTER. Time-series research supported by this program provides a unique historical context against which the ecological effects of the upcoming El-Niño can be gauged. As coral bleaching negatively affects coral reproduction, and previous El Niño events have been associated with globally-depressed coral recruitment, it is reasonably to hypothesize that coral recruitment in Moorea will change in magnitude (i.e., declining density) and type (i.e., taxonomic composition) over the next year. These possibilities have important implications, because coral recruitment mediates community resilience to disturbances, and modulates the trajectories of future reef development. In this 12-month project, a program of mensurative and manipulative experiments will be conducted to addressed four hypotheses: (1) coral recruitment will be depressed following El Niño-related seawater warming, (2) warming will affect post-settlement success of corals, (3) for Pocillopora, the effects on coral recruitment will be modulated through density-dependent processes, and (4) the resulting recruitment perturbations will modify trajectories of coral community development. The results of this research will have general application in revealing the demographic processes determining the response of coral reef communities to recurrent pulse disturbances such as El Niño events.