U.S. GLOBEC: Cross-Frontal Distributions and Exchange of Zooplankton on Georges Bank

美国 GLOBEC：乔治滩上浮游动物的跨前沿分布和交换

• 批准号: 9806444
• 负责人: Karen Wishner
• 金额: $ 33.15万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-11-01 至 2002-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9806444&HistoricalAwards=false
• 关键词: U.S.; GLOBEC; Cross; Frontal; Distributions

U.S. GLOBEC: Cross-frontal distributions and exchange of zooplankton on Georges Bank Cross-frontal distributions and exchange of zooplankton on Georges Bank are a primary focus of Phase 3 of the U.S. GLOBEC Georges Bank program, which has the broader goal of understanding the response of marine populations to global climate change, especially interactions between zooplankton and fish. This proposal examines the cross-frontal exchange of zooplankton at two sites important to the biology of GLOBEC-targeted species: the Northeast Peak Front in March (coincident with expected inflow of the copepod Calanus finmarchicus and the presence of cod larvae and high predator abundance) and the Southern Flank Tidal Mixing Front in June (coincident with high concentrations of Calanus and predators). Questions addressed include the interaction between vertically-stratified zooplankton distributions and the cross-frontal exchange at different depths, the temporal variability of these interactions on diel, tidal, and fortnightly scales, and the effects over time of the repeated passage of tidal fronts at particular locations along a bathymetric slope. Zooplankton abundances and vertical distributions will be determined from a Lagrangian sampling scheme utilizing transects relative to frontal position conducted at different phases of the tidal cycle (semidiurnal and fortnightly), and will be related to hydrographic structure, tidal phase, and distance from the front. In a complementary Eulerian sampling scheme employing time series sampling at fixed locations along a bathymetric slope, zooplankton distributions and variability will be related to the time since frontal passage. Vertically-stratified MOCNESS tows will be used to collect zooplankton. Cross-frontal exchange of zooplankton (different species and lifestages with different vertical distributions) will be estimated from concentration gradients across the front at different depths and along isopycnal surfaces, using various estimates of flow and water exchange provided by physical oceanographers.

美国GLOBEC：乔治斯海岸浮游动物的跨锋分布和交换乔治海岸浮游动物的跨锋分布和交换是美国GLOBEC乔治斯银行计划第三阶段的主要重点，该计划的更广泛目标是了解海洋种群对全球气候变化的反应，特别是浮游动物与鱼类之间的相互作用。这项建议审查了对GLOBEC目标物种生物学很重要的两个地点浮游动物的跨锋交换：3月份的东北高峰锋(与预期的桡足类Calanus finmarchicus流入和鳕鱼幼体的存在以及捕食者的高度丰富一致)和6月份的南侧潮汐混合锋(与Calanus和捕食者的高度集中一致)。所涉及的问题包括浮游动物垂直分层分布与不同深度的跨锋面交换之间的相互作用，这些相互作用在双周、潮汐和双周尺度上的时间变异性，以及沿等深坡度的特定位置潮汐锋重复经过的影响。浮游动物丰度和垂直分布将根据拉格朗日采样方案确定，该方案利用在潮汐周期的不同阶段(半日和每两周)进行的相对于锋面位置的横断面，并将与水文结构、潮汐阶段和与锋面的距离有关。在沿水深坡度的固定位置采用时间序列采样的互补欧拉采样方案中，浮游动物的分布和变异性将与锋面通过以来的时间有关。垂直分层的MOCNESS拖网将用于采集浮游动物。浮游动物的跨锋面交换(不同物种和生活方式具有不同的垂直分布)将利用物理海洋学家提供的各种流动和水交换估计，从锋面不同深度和沿等径面的浓度梯度估算。