COLLABORATIVE RESEARCH: What Controls the Transfer of Diatom Organic Matter to age-0 Pollock Prey in the Bering Sea Ecosystem?

白令海的高产量和经济重要性的Walleye Pollock商业性渔业依赖于鲜为人知的食物网路径。有机碳的初级生产者，特别是硅藻，被大型甲壳类浮游动物消耗，而这些浮游动物又被幼鳕鱼消耗。该系统的主导范式表明，了解大型甲壳类浮游动物生物量的变化可以帮助估计鳕鱼幼体的存活率；然而，最近的数据显示，大型甲壳类浮游动物的碳需求存在两个数量级的不确定性。这种不确定性影响了管理渔业的能力。提出了该系统的订正模型，其中包括考虑硅藻产生的有机物的数量和质量，以及这将如何限制对商业渔业的支持。在投资于测试这一方法的主要现场工作之前，该项目将评估硅藻有机质生产的预期变化幅度和相关误差，包括用于估计它的单个术语，即丰度、生长速度和细胞碳。这项工作将基于实验室实验和历史数据分析。该项目将通过对一名博士后助理的培训提供部分支持，为科技、经济和经济管理学院的劳动力发展作出贡献。本科生将通过毕格罗海洋科学实验室的REU项目和毕格罗的科尔比学院学期项目被带入科学领域。K-12的外展将通过参与成功和长期存在的Dauphin Island海洋实验室探索馆计划来促进。通过博客《比奇洛？S咖啡馆科学》和《比奇洛时事通讯》向公众宣传。该项目将启动的研究的长期目标是改进商业渔业管理的机械性和预测性模型。对于来自低营养层的碳在白令海生态系统中去向的机制关系，没有达成共识，因此，初级生产和渔业之间的简单比例关系被常规使用。自下而上地控制大型甲壳动物浮游动物(LCZ)这一0岁龄的大眼鳕鱼猎物，可以帮助限制初级生产者和鳕鱼渔业之间的这种耦合，但根据白令海生态系统研究(BEST)的估计，LCZ的碳需求存在两个数量级的不确定性。需要一个新的概念模型，该项目将开始通过侧重于硅藻来完善这一问题，硅藻的分布没有LC区那么零散，是LC Z的关键猎物。在理解硅藻损失过程的大小方面存在重大知识差距；理解白令海东部初级生产量和渔业之间的基本联系的下一个合乎逻辑的步骤是回答：可用于支持营养较高的生物的硅藻初级生产量的比例是多少，这种比例与哪些生物地球化学变量有关？在野外环境中测试这种方法之前，必须了解硅藻有机质产量的预期变化幅度和相关误差，包括进入该估计的各个术语(即丰度、生长速度、细胞碳)。该项目将利用从高纬度地区分离出的硅藻进行培养研究，并结合文献和最佳方案数据，以满足这一初步目标。

The highly productive and economically important Walleye Pollock commercial fishery of the Bering Sea depends on poorly understood food web pathways. Primary producers of organic carbon, notably diatoms, are consumed by large crustacean zooplankton, which, in turn, are consumed by juvenile pollock. The dominant paradigm for the system suggests that understanding changes in the biomass of large crustacean zooplankton can help estimate the survival of juvenile pollock; however, recent data show two orders of magnitude uncertainty in the carbon demand of large crustacean zooplankton. Such uncertainties impact the ability to manage the fishery. A revised model for the system has been proposed that involves consideration of both the quantity and quality of organic matter produced by diatoms and how this would constrain support for the commercial fishery. Before investing in a major field effort to test this approach, this project will assess the expected magnitude of change and associated errors, for diatom organic matter production, including the individual terms that are used to estimate it, i.e. abundance, growth rate, and cell carbon. This effort will be based on laboratory experiments and historical data analysis. The project will contribute to STEM workforce development through partial support for the training of a post-doctoral associate. Undergraduates would be entrained into the science through an REU program at Bigelow Laboratory for Ocean Sciences and through the Colby College Semester at Bigelow program. K-12 outreach will be facilitated through participation in the successful and long-standing Dauphin Island Sea Lab Discovery Hall program. Outreach to the general public will be accomplished through a blog, Bigelow?s Café Scientifique, and the Bigelow newsletter. The long-term goal for the research that this project would initiate is improved mechanistic and predictive models for commercial fisheries management.There is no consensus on the mechanistic relationship of where carbon from the lower trophic levels goes in the Bering Sea ecosystem, hence simple proportionality relationships between primary production and fisheries are used routinely. Bottom-up control on age-0 walleye pollock prey, i.e. large crustacean zooplankton (LCZ), could help constrain this coupling between the primary producers and pollock fishery, but there is a two-order-of-magnitude uncertainty in the LCZ carbon demand based on estimates from the Bering Sea Ecosystem Study (BEST). A new conceptual model is required and this project will begin to refine the issue by focusing on diatoms, which have a less patchy distribution than LCZ and are a key prey item of LCZ. A major knowledge gap exists in the understanding of the magnitude of diatom loss processes; the logical next step to understanding the fundamental linkage between primary production and fisheries in the eastern Bering Sea is to answer: what is the proportion of diatom primary production available for supporting higher trophic organisms and with which biogeochemical variables does this covary? Before testing this approach in a field setting, the expected magnitude of change and associated error for diatom organic matter production, including the individual terms that go into that estimate (i.e. abundance, growth rate, cell carbon), must be understood. This project will combine culture studies using diatoms isolated from high-latitude regions with literature and BEST program data to meet this initial objective.