RAPID: Effect of a Very Low NAO Event on the Abundance of the Lipid-Rich Planktonic Copepod, Calanus Finmarchicus, in the Gulf of Maine

这种桡足类动物，叫做Calanus finmarchicus，是缅因湾（GoM）浮游生物的主要成员，尽管它位于该物种亚北极范围的南部边缘。威尔金森盆地是墨西哥湾三大深层盆地之一，在夏季到冬季都有大量的早期发育阶段的C. finmarchicus，是墨西哥湾沿岸滩和滩的C. finmarchicus的来源。最近一项基于北大西洋C. finmarchicus栖息地特征的研究预测，在未来几十年里，气候驱动的变化将迫使C. finmarchicus向北分布，离开墨西哥湾。然而，在海湾地区，C. finmarchicus对环境变化的海洋学和生活史反应是复杂的，而且在很大程度上是未知的。本RAPID提案的研究利用了一个难得的机会来验证一个关于气候变化相关的外部强迫控制墨西哥湾C. finmarchicus丰度的假设。该假说认为，随着两年的滞后，北大西洋涛动（NAO）的出现，明显较低的C. finmarchicus丰度随之下降。低C. finmarchicus与NAO之间的因果关系的具体过程尚不清楚。这里的研究验证了一项预测，即2012年威尔金森盆地的C. finmarchicus丰度将非常低，这是自19世纪60年代以来有记录以来最负负的nao之一的两年后。将在威尔金森盆地和缅因州沿海地区的一个固定站进行实地观测，以一系列时间序列的形式测量水文、食物供应和C. finmarchicus阶段丰度，并辅以在苏格兰大陆架上进行的测量。一项研究调查将与2012年9月在缅因湾的预定巡航相协调，将在威尔金森盆地和整个墨西哥湾收集更多的数据。冷冻和乙醇保存的C. finmarchicus样本也将被收集用于群体遗传研究。丰度结果将与过去20年收集的历史时间序列和调查数据进行比较，以证实或驳斥NAO对GoM C. finmarchicus种群的极端影响的预期。C. finmarchicus富含脂肪的早期发育阶段为鲱鱼、鲭鱼和沙刺鱼等浮游生物鱼类提供了特别重要的能量来源，支持沿海渔业以及濒临灭绝的北大西洋露脊鲸的夏季居民种群，后者直接以C. finmarchicus为食。这项RAPID研究为了解黄颡鱼向墨西哥湾生态系统供应的变异性来源提供了所需的信息，这些数据将用于支持黄颡鱼种群对NAO和其他外部强迫源响应的耦合物理-生物模型的开发。存档的样本将用于基因分析，以解决美国盆地实施计划中海洋科学界提出的关于陆架-盆地连通性的研究问题。该项目有助于东北沿海海洋观测系统协会（NERACOOS）观测子系统的实施，该协会已确定有必要将观测浮游动物多样性的变化作为其区域建设规划的一部分。它还将通过COSEE的课程资源和缅因湾研究所的科恩互动学习中心，促进C. finmarchicus故事的发展，使其成为向K-12学生教授海洋科学的资产。

The copepod, Calanus finmarchicus, is a dominant member of the plankton in the Gulf of Maine, (GoM), despite its location at the southern edge of the species' subarctic range. Wilkinson Basin, one of the three deep basins in the GoM, harbors very high concentrations of the early developmental stages of C. finmarchicus in the summer through winter and serves as a source of C. finmarchicus to GoM coastal ledges and banks. A recent study based on C. finmarchicus habitat characteristics across the North Atlantic predicts that climate-driven change will force the distribution of C. finmarchicus northward out of the GoM over the next several decades. However, the oceanographic and life history responses of C. finmarchicus to environmental variability in the Gulf are complex and largely unknown. The research in this RAPID proposal takes advantage of a rare opportunity to test a hypothesis about the control of C. finmarchicus abundance in the GoM from climate change related external forcing. The hypothesis states that a distinctly lower C. finmarchicus abundance follows, with a two-year lag, the occurrence of a very negative North Atlantic Oscillation (NAO). The specific processes that causally connect low C. finmarchicus with the NAO are not known. The research here tests the prediction that C. finmarchicus abundance will be very low in Wilkinson Basin in 2012, two years after one of the most negative NAOs on record, dating back to the 1860?s. Field observations in the form of a time series of measurements of hydrography, food availability and C. finmarchicus stage abundance will be taken at a fixed station in Wilkinson Basin and in the Maine coastal region, supported by measurements taken on the Scotian Shelf. A research survey, coordinated with a scheduled cruise in the Gulf of Maine in September, 2012, will take additional collections in Wilkinson Basin and throughout the GoM. Frozen and ethanol preserved samples of C. finmarchicus will also be collected for population genetic studies. The abundance results will be compared with historical time series and survey data collected over the past two decades, confirming or refuting the expectation of extreme NAO influence on GoM C. finmarchicus populations. The lipid-rich early developmental stages of C. finmarchicus represent a particularly important energy source for planktivorous fish such as herring, mackerel and sand lance, supporting coastal fisheries as well as the summer resident populations of the endangered North Atlantic right whale, which feeds on C. finmarchicus directly. This RAPID research provides information needed to understand sources of variability in C. finmarchicus supply to the GoM ecosystem and the data will be used to support the development of coupled physical-biological models of responses of the C. finmarchicus population to the NAO and other sources of external forcing. Archived samples will be used for genetic analyses addressing research questions about shelf-basin connectivity developed by the ocean sciences community in the U.S. BASIN Implementation Plan. The project contributes to the implementation of the observing subsystem for the Northeast Association for Coastal Ocean Observing Systems (NERACOOS), which has identified the need for observing change in zooplankton diversity as part of its regional build-out planning. It will also contribute to development of the story of C. finmarchicus as an asset for teaching marine science to K-12 students, through COSEE curriculum resources and the Cohen Center for Interactive Learning at the Gulf of Maine Research Institute.