Collaborative Research: Larval Transport in a Coupled-Estuary-Shelf System: A Modeling Study

本计画将以蓝蟹为模式生物，以理论方法探讨河口-陆架耦合系统中平流、混合、生物行为及环境变异对幼体输运的交互影响。 虽然以前的研究主要集中在出口和重新进入河口的幼虫运输，有一个关键的需要系统地研究区域规模的河口之间的幼虫交换和招聘变异性的多个因素的相对重要性。数值环流模型和粒子跟踪算法已经成熟到可以解决这些问题的程度。 研究人员将使用耦合流体动力学粒子跟踪模型系统地隔离和评估平流，混合，有机体行为和环境变异的影响，并整合其复杂和非线性的相互作用。 观测到的风和流动驱动的环流模式将模拟计算易处理的半理想化的中大西洋湾的水动力模型。数值模型中的粒子将利用该地区实地调查和实验室行为研究中获得的广泛信息来模拟青蟹的早期生命阶段。 这是第一个建模工作，系统地集中在平流，混合，生物体行为和环境变化之间的复杂相互作用的三维数值模型，其中包括最新的理解亚网格尺度湍流过程，垂直分辨青蟹幼虫的行为，并检查河口系统之间的交换能力。了解招募变异的原因和沿海种群之间的联系强度是研究休闲和商业重要蓝蟹的重要途径。蓝蟹渔业是一种宝贵的资源，其可持续性目前在切萨皮克湾受到质疑。了解的物理过程，产生招聘的变化，以及河口种群的相互联系的程度，将有助于管理人员作出更明智的决定，维持一个可持续的蓝蟹渔业。虽然重点是蓝蟹，研究结果将解决基本的，普遍的问题，控制大规模运输的南极幼虫在大陆架上，他们返回苗圃地区的因素，以及河口系统之间的交流潜力。 除了提高我们对影响幼虫运输和招募的复杂因素的理解外，这项研究计划还具有很强的教育和推广组成部分，包括开发一个互动网页。一名本科暑期学生将获得数值建模和数据分析培训。此外，一名教师研究员将获得与科学家合作并将研究成果转化为教案的经验。研究人员参与MA-COSEE计划，教师研究员的指导以及网页的开发将促进科学家和教育工作者之间的直接互动，并使研究成果得到广泛传播。

This project will investigate the interactive effects of advection, mixing, organism behavior and environmental variability on larval transport in a coupled-estuary-shelf system using a theoretical approach, and the blue crab, Callinectes sapidus, as the model organism. Although previous research on larval transport has focused on export and re-entry to an estuary, there is a critical need to systematically examine the relative importance of multiple factors on the regional-scale exchange of larvae between estuaries and on recruitment variability. Numerical circulation models and particle-tracking algorithms have matured to the point where they are ready to address these problems. Investigators will use a coupled hydrodynamic-particle tracking model to systematically isolate and evaluate the effects of advection, mixing, organism behavior and environmental variability, and to integrate their complex and nonlinear interactions. Observed wind- and flow-driven circulation patterns will be simulated with a computationally tractable semi-idealized hydrodynamic model of the Middle Atlantic Bight. Particles within the numerical model will simulate blue crab early-life stages using the extensive information available from field investigations and laboratory behavior studies in this region. This is the first modeling effort that systematically focuses on the complex interactions between advection, mixing, organism behavior and environmental variability in a 3D numerical model that includes the latest understanding of sub-grid scale turbulent processes, vertically resolved blue crab larval behavior, and the ability to examine exchange between estuarine systems. Understanding the cause of recruitment variability and the strength of connections between coastal populations is a critical avenue of research for the recreationally and commercially important blue crab. The blue crab fishery is a valuable resource whose sustainability is currently in question in Chesapeake Bay. Understanding the physical processes that generate recruitment variability, and the degree of interconnectedness of estuarine populations, will help managers make more informed decisions for maintaining a sustainable blue crab fishery. Although focused on blue crabs, research results will be address fundamental, universal questions about factors that control large-scale transport of planktonic larvae on continental shelves, their return to nursery areas, and potential for exchange between estuarine systems. In addition to enhancing our understanding of the complex factors that affect larval transport and recruitment, this research program has a strong education and outreach component, including development of an interactive web page. One undergraduate summer student will gain numerical modeling and data analysis training. Also, one teacher Fellow will gain experience working with scientists and translating research results into lesson plans. The investigators involvement in the MA-COSEE program, the mentoring of a teacher Fellow, and development of a web page will promote direct interaction between scientists and educators and enable broad dissemination of research results.