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

在北方白令海和楚科奇海的四个主要底栖热点观察到大型底栖动物生物量持续较高。这些高产的底栖生物群落具有重要的生态意义，为以底栖生物为食的海洋哺乳动物和海鸟提供了丰富的猎物。这笔赠款支持探索有助于形成这些海底热点的物理和生物过程，并确定北极系统（包括冰，海洋和大气强迫）的变化将如何影响其形成和持续。更好地了解这些海底热点的形成和持续存在的机制很重要，需要本研究采用大气-冰-海洋系统的方法，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作用力。该小组将整合一套模型，包括一个冰-海洋-生态系统耦合模型和一个拉格朗日粒子跟踪模型，以评估有机物质的来源、运输途径和对底栖生物群落的供应。建模将涵盖从大气强迫到粒子输出通量的整个系统。为了从机制上了解太平洋北极地区的生态系统结构，需要建立海底-水层耦合的明确模型，并将提供基线信息，以更好地预测未来的生态系统变化。一旦完成模型验证和综合观测，该项目将广泛描述整个北方白令海和楚科奇海现有和潜在的海底热点位置和海底热点的碳源，包括目前采样不足的区域及其对持续气候和环境变化的脆弱性。它还将更好地了解促成海底热点形成的机制（例如，浮游动物放牧，生产和/或营养物质平流输入的季节和年际变化，电流的作用，会聚，湍流和热点形成中的颗粒聚集，海冰形成的时间，覆盖和退缩，大气强迫的年际或长期差异）。两者都有助于设计未来的实地工作，因为热点位置的综合空间分布可以指导基于地点的实地工作，模拟生态系统过程和转换的相对重要性将告知过程研究和分布研究的需求。随着气候变化的持续，大气强迫和洋流的强度和方向可能会发生变化，从而可能改变这些机制的汇合促进碳输出增加和海底热点形成的位置。了解这些相互关联的机制如何运作，以产生现有的海底热点，将使我们能够凭经验预测其未来的持久性或搬迁。建模工作的结果可以被科学界用于指导未来的实地工作和建模工作，更广泛地说，可以被管理人员和政策制定者用于指导管理和商业战略和准则的制定和实施。这项工作将包括主要侧重于K-12教育的外联活动，重点是大气强迫、海冰、海流和底栖-中上层耦合对白令海/楚科奇海系统的重要性以及持续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.