Collaborative Research: Controls on Hadal Megafaunal Community Structure: a Systematic Examination of Pressure, Food Supply, and Topography

知识价值。与极端静水压力相关的严峻技术挑战阻碍了hadal生态研究的重大进展，并使hadal系统成为地球上研究最少的栖息地之一。最近开发的全功能混合遥控车辆Nereus已经促使来自世界各地的科学家联合起来确定hadal科学中最重要的问题。通过这个项目，HADES项目，来自世界各地7个机构的pi将确定Hadal物种的组成和分布，Hadal压力的作用（压溶石浓度，压力下的酶功能），食物供应（POC与海沟生物丰度和生物量的分布，以及代谢率/能量需求）。深度/地形（种群遗传分化和空间连通性）对深海群落结构有影响。该项目将使用世界上第一个全海洋深度混合远程操作车辆（HROV）和唯一的全海洋深度成像着陆器（Hadal-Lander）来检查这些因素。这将为研究压力（及相关因素）、食物供应、生理适应和地形关系驱动的深海和深海群落结构提供一个比较框架。研究人员用来解释动物多样性和群落是如何在沟渠中形成的一级假设，完全缺乏检验这些假设所需的数据。因此，该项目将为世界上最好但鲜为人知的海沟之一——克马德克海沟（西南太平洋）提供第一批海底数据和样本。2010年首届国际海沟联系研讨会得出结论，需要确定海沟动物组成模式，并了解在构建这些生态系统中发挥作用的一级因素。巨型动物群落结构以及POC与底栖细菌生物量之间的关系将通过系统的高清成像和沉积物/动物取样样带，从深海到全海沟深度，沿着和垂直于海沟轴线，作为深度和位置的函数进行检查。种群遗传学方法将提供遗传分化水平和进化上独立的谱系，以评估海沟及其邻近深海平原的深度和地形在促进物种形成方面的作用。生理限制将通过检查选定动物的原位呼吸和三甲胺氧化（TMAO）等蛋白质稳定剂的组织浓度以及大分子的结构适应性来研究。这些目标代表了当前技术能力、科学理解和理论以及国际科学家联盟的专业知识的可实现和强有力的结合。更广泛的影响。这个项目将为深海研究开辟新的途径。这次考察和结果将通过积极的元数据和数据共享机制广泛传播给科学界和公众，获奖的海上网络教育课程和数据发布门户网站，博物馆展览，以及国家地理频道的主要电视节目，以海沟和深海科学为主题，包括地球最深处的生命形式，将吸引科学家和公众的想象力。在全球科学素养方面的外联活动将集中于与世界最深海沟的hadal动物生态学和进化有关的基本行星过程。一个每日更新的海上网站将实时向公众、博物馆和水族馆提供正在进行的巡航活动和发现。博士后、研究生和本科生的整体参与将为未被充分代表的群体提供专业和教育发展机会。此外，我们将鼓励感兴趣的生物学家、化学家、地质学家和其他更广泛的集体，推进生态学和进化理论的应用，以更好地理解栖息在hadal生态系统中的生物多样性。为此目的，研究人员将建立一个国际海洋科学联盟，致力于培训下一代海洋科学家，并与国际深海研究合作组织INDEEP合作。HROV Nereus的使用将提高该船的能力，用于广泛的学科用途，推动应用技术的进步，以进行严格的海底和深海科学，以及进一步的衍生技术，供更广泛的科学界使用。这个项目的结果将是第一个关于构成海沟群落的环境变量的研究，并为今后在创造和维持深海生物多样性的动态过程方面的工作奠定必要的基础。

Intellectual Merit. Severe technical challenges associated with the extremes of hydrostatic pressure have prevented major advances in hadal ecological studies, and relegated hadal systems to among the most poorly investigated habitats on Earth. The recent development of the fully functional Hybrid Remotely-Operated Vehicle Nereus has now prompted scientists from around the world to join together to identify the foremost standing questions in hadal science. Through this project, Hadal Ecosystems Studies (HADES) program, PIs from 7 Institutions from around the world will determine the composition and distribution of hadal species, the role of hadal pressures (piezolyte concentrations, enzyme function under pressure), food supply (distribution of POC with the abundance and biomass of trench organisms, and metabolic rates/energetic demand), and depth/topography (genetic divergence and spatial connectivity of populations) have on impacting deep-ocean community structure. This project will examine these factors using the world's first full-ocean depth hybrid remotely operated vehicle (HROV) in conjunction with the only full-ocean depth imaging lander (Hadal-Lander). This will pose a comparative framework for investigating hadal and abyssal community structure as driven by pressure (and associated factors), food supply, physiological adaptations, and topographic relationships. The investigators' first order hypotheses to explain how faunal diversity and communities are structured in trenches completely lack the data necessary to test them. Thus this project will provide the first seafloor data and samples in one of the world's best, yet little known trenches- the Kermadec Trench (SW Pacific Ocean). The first international Trench Connection Symposium in 2010 concluded the need to identify patterns of trench faunal composition and understand the first order factors that play a role in structuring these ecosystems. Megafaunal community structure and the relationship between POC and benthic bacterial biomass will be examined as a function of depth and location by systematic high-definition imaging and sediment/faunal sampling transects from abyssal to full trench depths both along and perpendicular to the trench axis. Population genetic approaches will provide levels of genetic divergence and evolutionarily independent lineages to assess the role of depth and topography in trenches and their adjacent abyssal plain in promoting the formation of species. Physiological constraints will be investigated by examining in-situ respiration of selected fauna and tissue concentrations of such protein stabilizers as trimethylamine oxide (TMAO), and the structural adaptations of macromolecules. These objectives represent an achievable and powerful combination of current technological capability, scientific understanding and theory, and the expertise of an international consortium of scientists.Broader impacts. The project will direct new avenues of research in the deep ocean. The expedition and results will be disseminated broadly to the scientific community and the public through both active metadata and data sharing mechanisms, award winning sea-going web-based education curricula and data-posting web portals, museum exhibits, and a major National Geographic television event featuring trench and deep-sea science, including life forms at the deepest depths on earth will engage the imagination of scientists and public alike. Outreach with respect to global scientific literacy will focus on the fundamental planetary processes associated with hadal faunal ecology and evolution at the world's deepest trenches. A daily-updated web site from sea will provide real-time public, museum, and aquaria access to the ongoing cruise activities and discoveries. The integral involvement of postdocs, graduate and undergraduate students will foster professional and educational advancement opportunities for underrepresented groups. In addition, we will stimulate a broader collective of interested biologists, chemists, geologists, and others to advance the application of ecological and evolutionary theory to better understand the biodiversity that inhabits hadal ecosystems. To this end, the investigators will develop an international consortium for hadal science dedicated to training the next generation of marine scientists and in conjunction with INDEEP, international collaboration for deep-sea research. The use of the HROV Nereus will advance this vehicle's capabilities for a broad range of disciplinary use, drive advances in applying technologies for conducting rigorous hadal and abyssal science, and further off-shoot technologies for use by the broader scientific community. The results of this project will be the first of its kind regarding the environmental variables that structure trench communities and lay the essential foundation for future work on the dynamic processes that create and maintain biodiversity in the deep ocean.