Copepod Population Dynamics in Hypoxic Coastal Waters: Physical and Behavioral Regulation of Resupply and Advective Losses

pi将对循环如何与缺氧诱导的行为和生理变化相互作用以影响沿海浮游动物种群动态的机制进行理解。他们将通过评估影响切萨皮克湾缺氧区桡足动物Acartia tonsa动态的两种潜在的对比机制来做到这一点。第一种假说认为，低氧地区桡足动物种群的维持需要通过风驱动的横向运输过程中的动物平流（迁移）来补充。第二种相反的假设是，底水缺氧改变了tonsa的垂直分布，从而使它们更容易受到该地区通过河口环流中地表水运输的平流损失（迁移）。他们将利用目前由美国国家科学基金会资助的切萨皮克湾物理海洋学研究项目，该项目将全面测量和模拟海湾中部地区的轴向和横向水交换。本研究将使用物理海洋学研究地点作为一个控制卷，其中海洋水的交换和这些交换的驱动机制将得到很好的定义。pi将对浮游动物进行高分辨率的时空采样，并将数据与低氧地区桡足动物行为、死亡率和产卵量的测量相结合。他们将使用一个改进的基于个体的tonsa生活史模型，结合循环来探索平流、行为、产卵和死亡率对种群动态的综合影响。除了增加我们对切萨皮克湾底水缺氧对桡足动物种群影响的认识外，该研究还将提高我们对浮游动物种群通过物理和生物过程的调节以及缺氧对沿海水域二次生产和食物网的影响的总体理解。该项目将加强现有的公众教育和宣传工作，使公众能够更好地了解缺氧对切萨皮克湾的影响。这将部分通过海洋科学卓越教育中心（COSEE）沿海趋势计划（现为角点实验室STEM中心学生学习活动计划）来完成。pi将通过开发合成浮游生物模型的在线互动版本，加强现有的一套在线教育模块（http://www.teachoceanscience.net/），重点关注切萨皮克湾“死亡区”的原因和后果。该研究还包括本科生暑期实习生通过本科生研究经验（REU）计划的参与。此外，这项研究将为切萨皮克湾溶解氧标准的制定和改进提供信息，将通过提供浮游动物在支持渔业生产力方面的作用的信息来支持切萨皮克湾计划的广泛倡议，并将为基于生态系统的渔业管理计划提供信息。

The PIs will develop a mechanistic understanding of how circulation interacts with hypoxia-induced behavioral and physiological changes to affect the population dynamics of coastal zooplankton. They will do this by assessing two potentially contrasting mechanisms influencing the dynamics of the copepod Acartia tonsa in the hypoxic zone of Chesapeake Bay. The first hypothesis is that maintenance of copepod populations in the hypoxic region requires replenishment by advection (immigration) of animals through wind-driven lateral transport processes. The second, counteractive, hypothesis is that bottom water hypoxia alters the vertical distribution of A. tonsa, thereby making them more susceptible to advective losses from the region (emigration) via surface water transport in the estuarine circulation. They will take advantage of a current NSF-funded physical oceanography research program in Chesapeake Bay that will comprehensively measure and model axial and lateral water exchanges in the mid-Bay region. The present study will use the physical oceanography study site as a Controlled Volume (CV) in which the oceanographic exchanges of water and the driving mechanisms for those exchanges will be well defined. The PIs will conduct high-resolution spatial and temporal sampling of zooplankton and combine the data with measurements of copepod behavior, mortality and egg production in the hypoxic region. They will use an improved Individual-Based Model of the life history of A. tonsa coupled with the circulation to explore the combined effects of advection, behavior, egg production, and mortality on population dynamics. In addition to increasing our knowledge of the impacts of bottom water hypoxia on copepod populations in Chesapeake Bay, the study will improve our general understanding of the regulation of zooplankton populations by physical and biological processes and the impacts of hypoxia on secondary production and food webs in coastal waters. The project will enhance existing public education and outreach efforts so that the public can be better informed about the effects of hypoxia on Chesapeake Bay. This will be accomplished in part through the Center for Ocean Science Education Excellence (COSEE) Coastal Trends program (now the Horn Point Laboratory STEM Center Student Learning Activities program). The PIs will enhance an existing set of online education modules (http://www.teachoceanscience.net/) that focus on the causes and consequences of the Chesapeake Bay's "Dead Zone" through development of an online interactive version of their synthetic plankton model. The study also includes participation by undergraduate summer interns through a Research Experience for Undergraduates (REU) program. In addition, this research will contribute information toward the development and improvement of dissolved oxygen criteria for Chesapeake Bay, will support broad initiatives of the Chesapeake Bay Program by providing information on the role of zooplankton in supporting productivity of fisheries, and will contribute information to ecosystem-based fisheries management plans.