Retrospective Analysis of Northeast Pacific Microzooplankton: a Window on Physical Forcing of Food Web Structure

对来自阿拉斯加湾的浮游动物样本进行回顾性分析，可以作为将海洋物理变化与高营养级分类群（特别是桡足类）的丰度和分布变化联系起来的一种手段。气候变化转化为桡足动物和鱼类产量变化的机制尚不清楚。许多研究人员假设，气候驱动的海洋物理变化改变了初级生产者的资源可得性，最终导致海洋动物的猎物可得性发生变化。在亚北极海域，微型浮游动物被认为是初级生产者和高级营养层之间的主要营养纽带，在沿海生态系统中可能发挥同样重要的作用。我们建议对这一关键营养环节进行回顾性分析，并结合气象学、海洋物理学和浮游生物生物学的数据，将为了解气候变化可能改变食物网结构和功能的机制提供一个窗口。样品组由Lugol保存的1升酸性水样组成，这些水样是在沿P线和P站（50ÝN, 145ÝW）进行海洋考察时收集的。垂直剖面（每个剖面采样8个离散深度）是1987年，1988年和1993年1997年（含）的巡航，大部分采样集中在冬季（2月）和春季（5月）。在1998年和1999年将收集更多样本。因此，13年的时间周期，连续7年，最终将可用于分析。将确定微型浮游动物群落（主要是原生动物）的丰度、生物量、大小结构和物种组成。由于微型浮游动物的定量采样技术是最近才开始广泛使用的，因此最终获得的数据集即使不是唯一的，也将是对这一重要浮游生物群体多年变化的罕见看法。此外，所有样本都是在海洋研究巡航期间收集的，为微型浮游动物数据提供了异常详细的背景框架。微型浮游动物数据将与物理和生物参数（如气象条件、海洋温度、混合层深度、营养物浓度、浮游植物生物量、大小结构、产量和桡足类生物量）进行比较。在相关环境数据的背景下分析浮游微动物样本将增加我们对海洋物理和更高营养水平变化之间的机制的理解，这些机制是通过浮游微动物介导的。了解食物网如何对环境的季节性和年际变化做出反应，对于预测模型的开发和验证至关重要，这是美国GLOBEC的主要目标。

Retrospective analysis of Northeast Pacific microzooplankton: a window on physical forcing of food web structure A retrospective analysis of microzooplankton samples from the Gulf of Alaska is proposed as a means of relating changes in ocean physics to changes in abundance and distribution of taxa at higher trophic levels, particularly copepods. The mechanisms by which climate regime shifts translate into changes in copepod and fish production are unknown. Many researchers have hypothesized that climate driven variability in ocean physics alters resource availability to primary producers, ultimately resulting in variation in prey availability to marine animals. Microzooplankton are known to be the major trophic link between primary producers and higher trophic levels in oceanic subarctic waters, and may play an equally important role in coastal ecosystems. We propose that retrospective analysis of this key trophic link, when combined with data on meteorology, ocean physics, and plankton biology, will provide a window onto the mechanisms by which climate shifts may alter food web structure and function. The sample set consists of acid Lugol's preserved 1 liter water samples collected during oceanographic cruises along Line P and at Station P (50ÝN, 145ÝW). Vertical profiles ( 8 discrete depths sampled per profile) are in hand from cruises in 1987, 1988, and 1993 1997 (inclusive), with most sampling focused during winter (Feb.) and spring (May) months. Additional samples will be collected during 1998 and 1999. Thus a 13 year time period, with 7 continuous years, ultimately will be available for analysis. Abundance, biomass, size structure, and species composition of the microzooplankton community (primarily protozoa) will be determined. Because quantitative sampling techniques for microzooplankton came into consist use fairly recently, the data set ultimately obtained will be a rare if not unique view of multi year variation in this important planktonic group. Furthermore, all samples were collected during oceanographic research cruises, providing an unusually detailed contextual framework for the microzooplankton data. Microzooplankton data will be compared to physical and biological parameters (e.g. meteorological conditions, ocean temperature, mixed layer depth, nutrient concentrations, phytoplankton biomass, size structure, and production, and copepod biomass). Analysis of microzooplankton samples in the context of related environmental data will increase our understanding of the mechanisms linking ocean physics and higher trophic level changes, as mediated through the microzooplankton. An understanding of how the food web responds to seasonal and interannual shifts in the environment is essential for the development and validation of predictive models, a major goal of U.S. GLOBEC.