The variability of zooplankton populations is controlled by external and internal forcing, with the former being principally large-scale changes in circulation, and the latter being driven by in situ growth, competition, and predation. Assessing the relative importance of these forcings is challenging and requires analyses of multifaceted observational data. As part of the U.S. GLOBEC Georges Bank program, a series of cruises were conducted in fall 1997, 1998, and 1999 to survey diapausing populations of Calanus finmarchicus and their predators in Wilkinson, Jordan, and Georges Basins of the Gulf of Maine. Station and underway sampling were conducted using net (1 m² MOCNESS) and bioacoustic (BIOMAPER-II) systems, respectively, to acquire vertically stratified data for zooplankton biomass, taxonomic, size, and life-stage composition, together with associated environmental data. The results show that the autumn diapausing C. finmarchicus abundance was much lower in 1998 than in 1997 or 1999, even though the overall zooplankton biomass levels were comparable between the three years. The size frequency distribution of the diapausing individuals had a bi-modal pattern in 1997 and 1999, but a single mode in 1998, indicating the demise of an early cohort of the diapausing stock. The relative biomass and computed energy demand of potential invertebrate predators (euphausiids, decapods, medusae, and siphonophores) was found to be higher in 1998 and could account for the missing C. finmarchicus cohort. Evidence collected from this study supports the hypothesis that local predation has the potential to control the diapausing stock of C. finmarchicus in the Gulf of Maine.

浮游动物种群的变异性受外部和内部强迫的控制，前者主要是循环的大规模变化，后者由原地生长、竞争和捕食驱动。评估这些强迫的相对重要性具有挑战性，需要对多方面的观测数据进行分析。作为美国 GLOBEC Georges Bank 计划的一部分，在 1997 年、1998 年和 1999 年秋季进行了一系列巡游，以调查在缅因湾的威尔金森、约旦和乔治盆地中滞育的Calanus finmarchicus及其捕食者种群。使用网（1 m ²MOCNESS) 和生物声学 (BIOMAPER-II) 系统分别获取浮游动物生物量、分类、大小和生命阶段组成的垂直分层数据，以及相关的环境数据。结果表明，尽管三年间浮游动物的总体生物量水平相当，但 1998 年秋季滞育的C. finmarchicus丰度远低于 1997 年或 1999 年。滞育个体的大小频率分布在 1997 年和 1999 年具有双峰模式，但在 1998 年是单一模式，表明早期滞育种群的消亡。1998 年发现潜在的无脊椎动物捕食者（磷虾、十足目、水母和虹吸管）的相对生物量和计算出的能量需求更高，这可能是造成缺失的原因C. finmarchicus队列。从这项研究中收集的证据支持这样的假设，即当地捕食有可能控制缅因湾C. finmarchicus的滞育种群。