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

智力上的功绩。与极端静水压力相关的严重技术挑战阻碍了哈达尔生态研究的重大进展，并将哈达尔系统归入地球上调查最少的栖息地之一。最近开发的全功能混合动力遥控飞行器Nereus现在促使来自世界各地的科学家联合起来，确定哈达尔科学中最重要的长期问题。通过这个项目，哈达尔生态系统研究(HADES)计划，来自世界各地的7个机构的PI将确定哈达尔物种的组成和分布，哈达尔压力(压电体浓度，压力下的酶功能)，食物供应(POC与海沟生物的丰度和生物量的分配，以及代谢率/能量需求)，以及深度/地形(种群的遗传差异和空间连通性)对深海群落结构的影响。该项目将使用世界上第一个全海洋深度混合遥控飞行器(HROV)和唯一的全海洋深度成像着陆器(Hadal-Lander)来检查这些因素。这将为研究由压力(及其相关因素)、食物供应、生理适应和地形关系驱动的哈达尔和深海群落结构提供一个比较框架。研究人员解释动物多样性和群落如何在战壕中构建的一阶假设完全缺乏测试它们所需的数据。因此，该项目将在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年第一次海沟连接国际专题讨论会的结论是，有必要确定海沟动物群的组成模式，并了解在构建这些生态系统方面发挥作用的一级因素。通过系统的高清晰度成像以及沿和垂直于海沟轴线的从深海到全海沟深度的沉积物/动物采样断面，将研究大型动物群落结构以及POC和底栖生物量之间的关系作为深度和位置的函数。种群遗传学方法将提供遗传分化程度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组织中三甲胺氧化物(TMAO)等蛋白质稳定剂的浓度，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一个国际科学家联盟的专业知识的可实现和强大的结合。该项目将为深海研究开辟新的途径。这次考察和成果将通过积极的元数据和数据共享机制向科学界和公众广泛传播，获奖的航海网络教育课程和数据发布门户网站、博物馆展品以及国家地理的一次重大电视活动以海沟和深海科学，包括地球最深处的生命形式为特色，将激发科学家和公众的想象力。在全球科学素养方面的宣传将侧重于与哈达尔动物群生态和世界最深海沟的进化有关的基本行星过程。从海上每日更新的网站将为公众、博物馆和水族馆提供实时访问正在进行的邮轮活动和发现的机会。博士后、研究生和本科生的整体参与将为代表不足的群体培养职业和教育晋升机会。此外，我们还将鼓励更多感兴趣的生物学家、化学家、地质学家和其他人应用生态学和进化论来更好地理解栖息在哈达尔生态系统中的生物多样性。为此目的，调查人员将建立一个哈达尔科学国际联盟，致力于培训下一代海洋科学家，并将与深海研究国际合作机构INDEEP合作。HROV Nereus的使用将提高该工具在广泛学科领域的使用能力，推动应用技术进行严格的哈达尔和深海科学的进步，并进一步发展供更广泛的科学界使用的副产品技术。该项目的成果将是关于构成海沟社区的环境变量的第一个此类结果，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.