CAREER: Testing the effects of predator-derived feces on host symbiont acquisition and health

气候变化和局部规模的人为压力正在使地球仪各地的珊瑚礁退化。当条件对珊瑚礁造成太大压力时，珊瑚可能会失去有益的微生物共生体（例如，共生甲藻科的甲藻），通过一种称为“漂白”的过程生活在它们的组织中。虽然共生藻科在珊瑚群落的健康中发挥着关键作用，但我们对环境中共生体对潜在宿主珊瑚的作用知之甚少。这项研究测试了在何种程度上吃珊瑚鱼的粪便，其中包含活共生藻科，促进共生体收购珊瑚在其早期生命阶段。它将产生关于珊瑚虫粪便如何影响珊瑚共生和健康的开创性知识，并将评估珊瑚虫鱼类作为珊瑚共生体组合驱动因素的生态重要性。这项研究还测试了食珊瑚动物的粪便在多大程度上是影响珊瑚健康的食物和营养物质的来源;这与漂白成年珊瑚的生存和恢复特别相关。这项研究最终可以为干预战略提供信息，以支持珊瑚礁的恢复能力和减缓珊瑚礁的退化。该项目的成果将在科学领域、本科教育项目中广泛传播，并通过多媒体内容和宣传向公众传播。休斯顿独立学区（Houston Independent School District，HISD）是美国第七大公立学校系统。这项工作将丰富资源不足的HISD高中中代表性不足的少数民族学生的环境科学课程。这项工作还将支持经济上处于不利地位的第一代本科生通过多年的研究经验追求STEM专业和职业。珊瑚、海绵、树木）和微生物群（例如，微真核生物，细菌）支撑着生态系统的生物多样性，生产力和稳定性。消费者，如捕食者和食草动物，通过营养相互作用塑造这些基础物种的群落。例如，食草动物通过消耗大型藻类竞争者，帮助维持珊瑚在珊瑚礁上的优势地位。然而，其他消费者对基础物种的间接影响很少被研究。很少有研究测试消费者如何影响珊瑚中的微生物群组装，即使珊瑚共生体（例如，共生甲藻科中的甲藻）在珊瑚礁的功能和持久性中起着关键作用。最近的研究表明，珊瑚鱼在游过珊瑚礁时会分泌大量的共生藻细胞。这项研究正在验证一个假设，即珊瑚虫的粪便通过支持珊瑚获得关键的共生体和营养物质来促进珊瑚在珊瑚礁上的优势。本研究将完成以下研究目标：（1）量化珊瑚鱼粪便对珊瑚共生体获取的贡献;（2）测试珊瑚鱼粪便对珊瑚健康和热应激恢复的影响程度。由于气候变化引起的白化和相关的死亡，全球珊瑚礁正在退化。该项目正在梳理与珊瑚虫粪便相关的营养物质和/或活共生体在多大程度上有助于漂白珊瑚在环境和热应力条件下的恢复力。该研究与两个教育目标紧密结合：（1）组织一个教师研究经验（RET）计划，在该计划中，高中教师可以将严格的学习模块纳入他们的环境系统课程设置进行开发和测试;和（2）通过与赖斯新兴学者计划（RESP）的合作，为本科生提供多年的研究经验该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Climate change and local-scale anthropogenic stressors are degrading coral reefs across the globe. When conditions become too stressful on reefs, corals can lose beneficial microbial symbionts (e.g., dinoflagellates in the family Symbiodiniaceae) that live in their tissues via a process called “bleaching”. Although Symbiodiniaceae play key roles in the health of coral colonies, we know little about the processes that make symbionts available in the environment to prospective host corals. This research test the extent to which coral-eating fish feces, which contain live Symbiodiniaceae, facilitate symbiont acquisition by corals in their early life stages. It will generate seminal knowledge on how corallivore feces impact coral symbioses and health, and will assess the ecological importance of corallivorous fishes as drivers of coral symbiont assemblages. This research also test the extent to which corallivore feces are a source of food and nutrients that impact coral health; this has particular relevance to the survival and recovery of bleached adult corals. This research can ultimately inform intervention strategies to support reef resilience and mitigate reef degradation. Results from this project will be communicated widely in scientific arenas, in undergraduate education programs, and to the public via multimedia content and outreach. The Houston Independent School District (HISD, Houston, TX) is the nation’s 7th largest public school system. This work will enrich environmental science curricula for underrepresented minority students at under-resourced HISD high schools. This work will also support economically disadvantaged and first-generation undergraduate students in pursuing STEM majors and careers through multi-year research experiences.Symbioses between foundation species (e.g., corals, sponges, trees) and microbiota (e.g., microeukaryotes, bacteria) underpin the biodiversity, productivity, and stability of ecosystems. Consumers, such as predators and herbivores, shape communities of these foundation species through trophic interactions. For instance, grazers contribute to the maintenance of coral dominance on reefs via consumption of macroalgal competitors. However, the indirect effects of other consumers on foundation species are rarely examined. Few studies have tested how consumers affect microbiota assembly in corals, even though coral symbionts (e.g., dinoflagellates in the family Symbiodiniaceae) play key roles in reef function and persistence. Corallivorous (coral-eating) fishes were recently demonstrated to egest large quantities of live Symbiodiniaceae cells as they swim across reefs. This research is testing the hypothesis that corallivore feces promote coral dominance on reefs by supporting coral acquisition of key symbionts and nutrients. The following research objectives will be accomplished: (1) to quantify the contribution of corallivorous fish feces to coral symbiont acquisition; and (2) to test the extent to which corallivorous fish feces influence coral health and recovery from thermal stress. Reefs are being degraded globally due to climate-change induced bleaching and associated mortality. This project is teasing apart the extent to which nutrients and/or live symbionts associated with corallivore feces contribute to the resilience of bleached corals under ambient and heat stress conditions. The research is tightly integrated with two education objectives: (1) to organize a Research Experience for Teachers (RET) program in which rigorous learning modules that high school teachers can incorporate into their Environmental Systems course offerings are developed and tested; and (2) to provide undergraduate students with a multi-year research experience through a partnership with the Rice Emerging Scholars Program (RESP).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.