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

这种名为Calanus finmarchicus的桡足动物是缅因湾(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GOM的三大深水盆地之一，夏季到冬季是Finmarchicus早期发育阶段的聚集地，是C.finmarchicus到GOM海岸带和堤岸的源头。最近一项基于北大西洋Finmarchicus栖息地特征的研究预测，气候驱动的变化将迫使C.finmarchicus在接下来的几十年里向北分布在GoM之外。然而，Finmarchicus对墨西哥湾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。这项快速提案中的研究利用了一个难得的机会来检验一个假设，即气候变化相关的外部强迫对海洋生态系统中Finmarchicus丰度的控制。该假说指出，随着北大西洋涛动(NAO)的出现，在两年的滞后之后，Finmarchicus的丰度明显降低。低碳微囊藻与NAO之间的因果联系的具体过程尚不清楚。这项研究测试了2012年威尔金森盆地Finmarchicus丰度将非常低的预测，这是自1860年S以来有记录以来最负的NAO之一的两年后。现场观测将在威尔金森盆地和缅因州沿海地区的一个固定站点进行，并得到对斯科特陆架的测量支持。一项研究调查，配合2012年9月在缅因湾的一次预定邮轮，将在威尔金森盆地和整个GoM进行更多的收集。冷冻和乙醇保存的Finmarchicus样本也将被收集用于种群遗传学研究。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，证实或驳斥NAO对GoM C.finmarchicus种群的极端影响的预期。Finmarchicus富含脂肪的早期发育阶段是鲱鱼、鲱鱼和沙枪鱼等浮游性鱼类的特别重要的能量来源，支持沿海渔业以及直接以C.finmarchicus为食的濒危北大西洋露脊鲸的夏季居留种群。这项快速研究提供了了解Finmarchicus向GOM生态系统供应的变异性来源所需的信息，这些数据将用于支持建立C.finmarchicus种群对NAO和其他外部强迫来源的反应的物理-生物耦合模型。存档的样本将用于基因分析，解决海洋科学界在美国盆地实施计划中提出的陆架-盆地连通性研究问题。该项目有助于实施东北沿海海洋观测系统协会的观测分系统，该协会已确定有必要观测浮游动物多样性的变化，作为其区域扩建规划的一部分。它还将通过COSEE课程资源和缅因湾研究所的科恩互动学习中心，帮助发展C.finmarchicus的故事，将其作为向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.