Long-Term Changes in California Current Zooplankton Assemblages: A Retrospective Analysis

职务名称：加州当前浮游动物的长期变化回顾性分析项目摘要：海洋浮游动物是物理气候信号传播到海洋鱼类种群的主要途径之一。现在的证据表明，浮游动物生物量的地理广泛的变化与东北太平洋的大气和海洋环流的变化相一致。然而，这样的分析散装浮游动物生物量不区分类群不同的生活史，其中一些是重要的营养链的食饵性鱼类和其他人没有。浮游动物的物种组成可以强烈影响浮游动物-鱼类联系的强度，从而改变招聘成功。机制理解 定量建模 气候与食鱼性鱼类之间的联系将取决于对浮游动物区系的具体了解以及不同浮游动物类群对东北太平洋环流和生产力变化的不同反应。 我们提出了一个回顾性分析的过去43/a的几十年的加州电流系统（CCS）。我们将使用高质量的CalCOFI浮游动物收集，连同相关的水文数据和大气强迫指数，以了解从1951年到现在的浮游动物变化的原因。浮游动物组成的三个方面将进行调查：在高层次的分类组成的所有holozooplankton类群，包括凝胶和甲壳类动物的形式的变化;桡足类和选定的其他类群的物种组成的变化;和营养结构和氮经济的变化，从两个物种的particlegrafing桡足类的N稳定同位素组成推断。 我们假设，有差异，分类特异性的反应：在东北太平洋的气候，包括1976 - 77年变暖事件的年代尺度变化。 .厄尔尼诺和来自赤道地区和亚北极太平洋气流的其它年际变化。 沿岸上升流和跨海岸输送强度的区域差异。 我们的研究将首次提供对太平洋浮游动物物种数十年变化的了解。我们将揭示导致CCS浮游动物生物量长期下降70%的类群。我们将建立CCS中部和南部海域种群变化的时间一致性，并以此分析与亚北极太平洋相关浮游动物物种的协变。这些研究将为设计新的全球海洋生态系统实地研究和开发东北太平洋远洋生态系统模型奠定基础。

Title: Long term Changes in California Current Zooplankton A Retrospective Analysis Project Summary: Marine zooplankton are one of the primary pathways through which physical climate signals propagate to marine fish populations. Evidence now shows geographically extensive changes of zooplankton biomass in concert with variations in the atmospheric and oceanic circulation in the NE Pacific. However, such analyses of bulk zooplankton biomass do not distinguish among taxa with diverse life histories, some of which are important trophic links to planktivorous fishes and others of which are not. The species composition of the zooplankton can strongly influence the intensity of zooplankton fish linkages, and consequently alter recruitment success. Mechanistic understanding and quantitative modeling of climate linkages to planktivorous fishes will depend upon specific knowledge of the zooplankton fauna and the differential responses of different zooplankton taxa to variations in circulation and productivity of the NE Pacific. We propose a retrospective analysis of the past 43/a decades of the California Current System (CCS). We will use the high quality CalCOFI zooplankton collection, together with associated hydrographic data and indices of atmospheric forcing, to understand the causes of changes in the zooplankton from 1951 to the present. Three aspects of the zooplankton composition will be investigated: changes in the high level taxonomic composition of all holozooplankton taxa, including gelatinous and crustacean forms; changes in the species composition of copepods and selected other taxa; and changes in trophic structure and nitrogen economy as inferred from the N stable isotope composition of two species of particlegrazing copepods. We hypothesize that there have been differential, taxon specific responses to: ª Decadal scale changes in the climate of the NE Pacific, including the 1976 77 warming event. . El Nifio and other interannual variations in flow from the equatorial region and from the Subarctic Pacific. Regional differences in the intensity of coastal upwelling and cross shore transport. Our studies will provide, for the first time, an understanding of multi decadal zooplankton species changes in the Pacific. We will uncover the taxa responsible for the longterm 70% decline in CCS zooplankton biomass. We will establish the temporal coherence of population changes in the central and southern sectors of the CCS, with which to analyze the covariation with related zooplankton species in the Subarctic Pacific. These studies will form the foundation for the design of new GLOBEC field studies and the development of NE Pacific pelagic ecosystem models.