Collaborative Research: The physiology and ecology of widespread 'stress tolerant' coral endosymbionts: coral 'saviors' or opportunistic invaders?

合作研究：广泛的“耐压”珊瑚内共生体的生理学和生态学：珊瑚“救世主”还是机会主义入侵者？

• 批准号: 1258065
• 负责人: Mark Warner
• 金额: $ 45.65万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1258065&HistoricalAwards=false
• 关键词: Collaborative; Research; physiology; ecology; widespread

Ocean warming is affecting life on our planet in many ways. High temperature can disrupt the endosymbioses between dinoflagellate algae (Symbiodinium spp.) and reef-building corals (i.e. coral bleaching), thereby risking the global loss of a critical marine ecosystem. The physiological, ecological and evolutionary responses of coral-dinoflagellate symbioses to environmental stress brought on by global climate change are complex. The spread of certain types of symbiotic algae may increase the thermal stress tolerance among corals and help them persist in warmer oceans, but perhaps not without trade-offs to the health of the coral. The dinoflagellate tentatively named Symbiodinium trenchi has become increasingly more common in numerous corals throughout the Caribbean, but is often at low-abundance relative to other symbionts. While S. trenchi can increase in abundance during and after warming, it is often displaced by other symbionts following a return to normal conditions. Genetic evidence indicates that S. trenchi recently invaded and/or expanded in the Caribbean and has developed associations with many corals that seem to be poorly optimized, or mal-adapted, relative to the symbioses it maintains with corals in the Indo-Pacific. This project will investigate the symbiosis ecology and physiology of S. trenchi in corals from the Atlantic and Pacific Oceans. Bleaching experiments will examine the effects of increased temperature on transfer of carbon from the algae to the host coral (via stable isotopic tagging), as well as photosynthesis and growth among colonies harboring S. trenchi compared to colonies harboring other Symbiodinium spp. The potential for symbiont community shifts as well as altered long-term colony growth based on bleaching severity and recovery time will be investigated. A reciprocal transplant study will examine the competitive interaction and stability of symbionts among Pacific corals. These studies will test if the continued spread of S. trenchi will affect coral growth in the Caribbean and whether it might behave similarly in the Indo-Pacific if environmental conditions worsen. The results from this project have the potential to supply transformative information regarding how (or if) a widely distributed symbiotic algal species may influence the resilience of reef-building corals and their potential to survive projected increases in ocean warming due to climate change. In addition to training one postdoctoral scholar and several graduate students, this project will enhance scientific discovery and participation of underrepresented groups via several outreach efforts with the Palau National Aquarium, Palau International Coral Reef Center, and local schools. Educational units in marine symbioses and science will be developed with several local high school teachers and students, and unique research opportunities will be provided to students at the Palau Community College. Likewise, a new educational display addressing how global climate may impact coral reefs, and describing the current research to better understand the physiology of coral-algal symbioses, will be developed and presented at the University of Delaware open house "Coast Day." The display will be donated subsequently to the Palau Aquarium for future use.This award is co-funded by NSF's Office of International and Integrative Activities.

海洋变暖正在以多种方式影响我们星球上的生命。高温会破坏甲藻（共生藻属）和造礁珊瑚之间的内共生（即珊瑚白化），从而导致全球重要海洋生态系统面临丧失的风险。珊瑚-甲藻共生体对全球气候变化带来的环境压力的生理、生态和进化反应是复杂的。某些类型的共生藻类的传播可能会增加珊瑚的热应激耐受性，并帮助它们在温暖的海洋中生存，但也许并非没有对珊瑚的健康进行权衡。这种甲藻暂时命名为海沟共生藻，在加勒比地区的众多珊瑚中变得越来越常见，但相对于其他共生体来说，其丰度往往较低。虽然海沟链霉菌在变暖期间和变暖后数量会增加，但在恢复正常条件后，它通常会被其他共生体取代。遗传证据表明，海沟海藻最近在加勒比海地区入侵和/或扩张，并与许多珊瑚建立了联系，相对于它与印度太平洋珊瑚的共生关系来说，这些珊瑚似乎优化不佳或适应不良。该项目将研究大西洋和太平洋珊瑚中海沟藻的共生生态学和生理学。漂白实验将检查温度升高对碳从藻类转移到宿主珊瑚（通过稳定同位素标记）的影响，以及与含有其他共生藻属的菌落相比，含有海藻的菌落的光合作用和生长的影响。将调查共生群落转变的可能性以及基于漂白严重程度和恢复时间改变的长期菌落生长的可能性。相互移植研究将检查太平洋珊瑚之间共生体的竞争相互作用和稳定性。这些研究将测试海沟藻的持续扩散是否会影响加勒比海地区的珊瑚生长，以及如果环境条件恶化，它是否会在印度-太平洋地区表现出类似的行为。该项目的结果有可能提供关于广泛分布的共生藻类物种如何（或是否）影响造礁珊瑚的恢复力及其在气候变化导致的预计海洋变暖加剧的情况下生存的潜力提供变革性信息。除了培训一名博士后学者和几名研究生外，该项目还将通过与帕劳国家水族馆、帕劳国际珊瑚礁中心和当地学校的多项外展工作，加强科学发现和代表性不足群体的参与。将与当地几名高中教师和学生共同开发海洋共生和科学教育单元，并将为帕劳社区学院的学生提供独特的研究机会。同样，将在特拉华大学开放日“海岸日”上开发并展示一个新的教育展览，讨论全球气候如何影响珊瑚礁，并描述当前的研究，以更好地了解珊瑚-藻类共生的生理学。该展示品随后将捐赠给帕劳水族馆以供将来使用。该奖项由美国国家科学基金会国际和综合活动办公室共同资助。