Collaborative Research: Formation and Persistence of Benthic Biological Hotspots in the Pacific Arctic

在北白令海和楚科奇海的四个主要底栖动物热点地区，观察到大型底栖动物生物量持续高。这些高产的底栖生物群落具有重要的生态意义，为以底栖动物为食的海洋哺乳动物和海鸟提供了丰富的猎物。该基金支持探索导致这些底栖热点形成的物理和生物过程，并确定北极系统（包括冰、海洋和大气强迫）的变化将如何影响它们的形成和持续。更好地了解这些底生物热点的形成和持续机制是很重要的，并且需要本研究中采用的大气-冰-海洋系统方法，因为这些形成机制涉及北极系统的多个组成部分，包括海冰和海洋过程的生物和物理组成部分以及大气强迫。该小组将整合一套模型，包括冰-海洋-生态系统耦合模型和拉格朗日粒子跟踪模型，以评估底栖生物群落有机物的来源、运输途径和供应。建模将涵盖整个系统，从大气强迫到粒子出口通量。对太平洋北极地区生态系统结构的机制理解需要明确地模拟底-上层耦合，并将为更好地预测未来生态系统的变化提供基线信息。一旦模型验证和观测综合完成，该项目将对整个白令海北部和楚科奇海（包括目前采样不足的地区）底栖生物热点的现有和潜在位置以及碳源进行大规模描述，以及它们对持续气候和环境变化的脆弱性。它还将更好地了解促进底栖热点形成的机制（例如，浮游动物的放牧、平流产品和/或营养物质输入的季节性和年际变化、洋流、辐合、湍流和颗粒聚集在热点形成中的作用、海冰形成、覆盖和退缩的时间、大气强迫的年际或长期差异）。两者都有助于未来野外工作的设计，因为热点位置的综合空间分布可以指导基于地点的野外工作，而模拟生态系统过程和转换的相对重要性将为过程研究和分布研究的需求提供信息。随着气候的持续变化，大气强迫和洋流的强度和方向可能会发生变化，这些机制的汇聚可能会改变促进碳输出和底栖热点形成的位置。了解这些相互关联的机制是如何产生现有的底栖热点的，将使我们能够根据经验预测它们未来的持久性或迁移。建模工作的结果既可以被科学界用来指导未来的实地工作和建模工作，也可以被更广泛的管理者和政策制定者用来指导管理和商业战略和指导方针的发展和实施。这项工作将包括主要以K-12教育为重点的外展活动，重点关注大气强迫、海冰、洋流和底-上层耦合对白令海/楚科奇海系统的重要性，以及持续的气候变化对该系统的影响。

Persistently high macrofaunal benthic biomass has been observed at four major benthic hotspots in the Northern Bering and Chukchi Seas. These highly productive benthic communities are ecologically important and provide abundant prey for benthic-feeding marine mammals and seabirds. This grant supports the exploration of the physical and biological processes that contribute to the formation of these benthic hotspots, and a determination of how changes in the Arctic system (including ice, ocean, and atmospheric forcing) will affect their formation and persistence. A better understanding of the mechanisms for the formation and persistence of these benthic hotspots is important and requires the atmosphere-ice-ocean system approach taken in this study, since these formation mechanisms involve multiple components of the Arctic system, including both biological and physical components of sea ice and ocean processes and atmospheric forcing. The group will integrate a suite of models, including an ice-ocean-ecosystem coupled model and a Lagrangian particle-tracking model, to evaluate source, transport pathway, and supply of organic matter to the benthic community. The modeling will span the entire system from atmospheric forcing down to particle export flux. Explicitly modeling benthic-pelagic coupling is needed for a mechanistic understanding of the ecosystem structure in the Pacific Arctic region and will provide baseline information to better predict future ecosystem shifts. Once the model validation and synthesis with observations are accomplished, the project will have a broad-scale description of the existing and potential locations of benthic hotspots and carbon sources for benthic hotspots across the entire northern Bering and Chukchi Seas, including regions that are presently under-sampled, and their vulnerabilities to ongoing climate and environmental changes. It will also have a better understanding of the mechanisms contributing to benthic hotspot formation (e.g., zooplankton grazing, seasonal and inter-annual variability in advected inputs of production and/or nutrients, role of currents, convergences, turbulence, and particle aggregation in hotspot formation, timing of sea ice formation, cover, and retreat, inter-annual or long-term differences in atmospheric forcing). Both can contribute to the design of future field efforts, since the comprehensive spatial distribution of hotspot location can guide place-based field efforts and the relative importance of modeled ecosystem processes and transformations will inform needs for process studies and distributional studies. With ongoing climate change, atmospheric forcing and ocean currents are likely to change in strength and direction, potentially modifying the locations where the convergence of these mechanisms promotes enhanced carbon export and benthic hotspot formation. Understanding of how these linked mechanisms operate to produce the existing benthic hotspots will permit us to predict empirically their future persistence or relocation. The results of the modeling effort can be used both by the scientific community in guiding future fieldwork and modeling efforts and more broadly by managers and policy makers in guiding the development and implementation of management and commercial strategies and guidelines. This work will include outreach activities primarily focused on K-12 education, focusing on the importance of atmospheric forcing, sea ice, currents, and benthic-pelagic coupling to the Bering/Chukchi Sea system and the impacts of ongoing climate change on that system.