U.S.-GLOBEC: NWA Georges Bank: Effects of climate variability on Calanus dormancy patterns and population dynamics in the Northwest Atlantic

哲水蚤桡足类是全世界海洋的关键生物，以高速率消耗初级和次级生产物，并作为无脊椎动物、幼体和小型中上层鱼类、海鸟和海洋哺乳动物的猎物。许多温带和高纬度地区最丰富的桡足类，包括西北大西洋的Calanus finmarchicus，可以在休眠中度过部分生命周期，这是一种受抑制的发展状态。在休眠期间，桡足类逃离无生产力的表层沃茨，并在深水中居住数月，之后它们出现并迁移到表面，通常在春季开花之前。桡足类从休眠中出现的时间和丰度为活跃季节的人口增长设定了初始条件，可能对桡足类人口动态和仔鱼的摄食和生长至关重要。同样，进入休眠的时间和随之而来的减少猎物的可用性在表面沃茨，可能是重要的表面食草动物的种群动态。控制休眠开始和出现的物理和生物因素是不知道的Calanus finmarchicus或其他开放的海洋桡足类species.This项目的目的是确定的因素，控制休眠的开始和出现在Calanus finmarchicus在西北大西洋使用两个区域间的比较休眠响应和相关的环境条件和个人为基础的模型（IBM）模拟。该研究测试的假设，即种群动态的区域间差异是由不同的环境条件作用于桡足类相似的休眠和生理速率对环境参数的反应。将汇编来自西北大西洋七个区域的数据集，并将其与观测生物物理数据集进行比较，以检验有关休眠控制机制的假设。IBM模拟将在个别地区运行，以测试改进的休眠控制假设的可行性。还将进行IBM模拟，以测试该模型对休眠和生理速率函数的不确定性的敏感性，并评估种群对地表和深水温度的实际年际变化以及春季水华的时间和幅度变化的反应。模拟种群对气候变化的响应。finmarchicus将与C. pacificus和C. marshallae拟议研究的结果对于了解影响浮游生物主要群体季节性生产的基本过程将是重要的。这方面的知识是至关重要的，以了解气候变化对西北大西洋和东北太平洋的食物网的整体营养影响。拟议的研究涉及一名硕士研究生和一名博士后学生的直接参与。这项研究代表了新罕布什尔州大学和NOAA太平洋渔业环境实验室（PFEL）的科学家之间的持续合作，它包括与达尔豪西大学和加拿大渔业和海洋实验室部的科学家的合作。此外，从这个建议预期的结果将适用于当前和拟议的GLOBEC桡足类种群建模工作。从这项工作中获得的信息将被证明是有价值的管理海洋哺乳动物（北方露脊鲸，主要以C。finmarchicus），以及鳕鱼，鲱鱼和其他鱼类物种在乔治银行和缅因州的海湾和了解气候变化对这些物种的影响。

Calanoid copepods are key organisms throughout the world's oceans, consuming primary and secondary production at high rates, and serving as prey for invertebrates, larval and small pelagic fish, seabirds, and marine mammals. Many of the most abundant copepods in temperate and high latitudes, including Calanus finmarchicus in the Northwest Atlantic, can spend part of their life cycle in dormancy, a state of suppressed development. During dormancy, copepods escape unproductive surface waters and reside in deep water for several months, after which they emerge and migrate to the surface, usually prior to the spring bloom. The timing and abundance of copepods emerging from dormancy set initial conditions for population growth in the active season and is likely critical for both copepod population dynamics and for feeding and growth of larval fish. Similarly, the timing of entry into dormancy and consequent reduction of prey availability in surface waters, may be important to population dynamics of surface planktivores. The physical and biological factors that control onset of and emergence from dormancy are not known for Calanus finmarchicus or other open ocean copepod species.This project aims to identify the factors that control onset of and emergence from dormancy in Calanus finmarchicus in the Northwest Atlantic using both an inter-regional comparison of dormancy response and associated environmental conditions and individual-based model (IBM) simulations. The research tests the hypothesis that inter-regional differences in population dynamics are caused by different environmental conditions acting on copepods with similar dormancy and physiological rate responses to environmental parameters. Data sets from seven regions of the Northwest Atlantic will be compiled and compared to observational bio-physical data sets to test hypotheses about dormancy control mechanisms. IBM simulations will be run in individual regions to test the plausibility of the refined dormancy control hypotheses. IBM simulations will also be run to test the sensitivity of the model to uncertainty in dormancy and physiological rate functions, and to evaluate population responses to realistic interannual variability in surface and deepwater temperature and shifts in the timing and magnitude of the spring bloom. Modeled population responses to climate variability in C. finmarchicus will be compared to similar ongoing analyses in C. pacificus and C. marshallae. The results of the proposed research will be important for understanding basic processes that influence seasonal production of a major group of plankton. This knowledge is critical to understanding the overall trophic impact of climate change on food webs of both the Northwest Atlantic and Northeast Pacific.The proposed research involves the direct participation of one Master's level graduate student and one postdoctoral student. This research represents a continuing collaboration between scientists from the University of New Hampshire and NOAA's Pacific Fisheries Environmental Laboratory (PFEL), and it includes collaborations with scientists at Dalhousie University and Canadian Department of Fisheries and Oceans Laboratories. In addition, the results expected from this proposal will be applicable to current and proposed GLOBEC copepod population modeling efforts. The information gained from this work will prove valuable to management for marine mammals (northern right whale that feeds primarily on C. finmarchicus), as well as cod, herring and other fish species on Georges Bank and in the Gulf of Maine and for the understanding of impacts of climate change on these species.