US-GLOBEC: Cross-Frontal Processes and Recruitment Variabiliorges Bank -- Diet of Calanus Finmarchicus Copepodiduplii

US-GLOBEC：跨前沿流程和招募 Variabiliorges 银行 - Calanus Finmarchicus Copepodiduplii 的饮食

• 批准号: 9806375
• 负责人: Dian Gifford
• 金额: $ 33.8万
• 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=9806375&HistoricalAwards=false
• 关键词: US; GLOBEC; Cross; Frontal; Processes

US-GLOBEC: Cross-Frontal Processes and Recruitment Variability on Georges Bank - Diet of Calanus finmarchicus Copepodids and Nauplii This program will examine the biological and physical processes controlling the distribution and abundance of marine animals in time and space, especially as related to cross-frontal processes. The specific focus of this proposal is to describe quantitatively the contribution of nano- and micro- plankton prey fields to recruitment of target copepod populations on the Bank. We hypothesize that copepods and nauplii located in frontal regions and on the well-mixed (on-Bank) side of fronts experience an enriched food environment relative to the stratified (off-Bank) side of fronts. We will first define the fronts by hydrographic surveys which include CTD/rosette sampling of the nano- and microplankton (i.e. plant and animal prey 2-200 um in size) prey field which our studies in Phases 1 and 2 of the GLOBEC Northwest Atlantic Program have demonstrated are heavily utilized by target copepods and larval fish. Exchange rates of these organisms will be evaluated and compared to exchange rates of conservative water column properties from the same hydrographic casts. We will evaluate prey fields and measure consumption of nano- and microplankton organisms by copepodid and feeding naupliar stages of the calanoid copepod Calanus finmarchicus in two cross-frontal areas which are characteristic of two different seasons: (1) the Northeast Peak Front, which exhibits its strongest surface thermal signal in February-March and (2) the Tidal Mixing Front which separates waters of the Bank crest from the southern flank during late spring and summer (late May-August). We focus on C finmarchicus because this species dominates the zooplankton biomass of Georges Bank during the January-June period. We emphasize fronts on the Northeast Peak and the Southem Flank because these are potential sites for cross-frontal transport of water, nutrients and plankton onto the Bank. We focus on the Northeast Peak because it is an area of enhanced production of both plankton and benthos relative to the rest of the Bank. And we compare zooplankton across the tidal mixing front between the Bank crest and the Southern Flank because U.S.-GLOBEC studies conducted during 1994-1996 indicate that, although C. finmarchicus nauplii are advected onto the Bank crest early in the season, strong cohorts do not subsequently develop, possibly as a result of intense predation pressure in this area. Ingestion rates of nauplii and copepodids will be measured directly in shipboard experiments using natural prey assemblages. The proximate influence of omnivorous feeding will be interpreted in the context of the in situ prey field and physical regime. Ultimately, the influence of plant versus animal prey in consumer diet will be addressed collaboratively in the context of measurements made by other investigators of consumer distribution, condition, life history parameters and production.

美国-GLOBEC：横额过程和补充变异性乔治斯浅滩-食饵的Calanus finmarchicus桡足类和无节幼体这个项目将研究控制海洋动物在时间和空间上的分布和丰度的生物和物理过程，特别是与跨额过程有关的过程。这项提案的具体重点是定量描述纳米和微型浮游生物捕食场对在岸上招募目标桡足类种群的贡献。我们假设，位于前锋区域和混合良好的前锋(岸上)一侧的桡足类和无节幼体相对于分层的前锋(岸外)一侧经历了丰富的食物环境。我们将首先通过水文调查确定前线，其中包括对微型和微型浮游生物(即大小为2-200微米的动植物猎物)猎物领域的CTD/玫瑰取样，我们在GLOBEC西北大西洋计划第一阶段和第二阶段的研究表明，目标桡足类和幼鱼大量利用这些猎物领域。这些生物的交换率将被评估，并与来自相同水文铸型的保守水柱性质的交换率进行比较。我们将在两个具有两个不同季节特征的交叉锋面区域评估捕食场和测量摄食幼虫阶段的桡足类桡足类Calanus finmarchicus对纳米和微型浮游生物的消耗：(1)东北峰锋，在2-3月表现出最强的表面热信号；(2)潮汐混合锋，在春末和夏季(5月下旬-8月)将岸顶水域与南岸隔开。我们把重点放在C finmarchicus上，因为在1-6月期间，这种物种在乔治斯浅滩的浮游动物生物量中占主导地位。我们强调东北山顶和南侧的锋面，因为这些是水、营养物质和浮游生物跨锋面输送到岸上的潜在地点。我们把重点放在东北峰，因为相对于海岸的其他地方，它是一个浮游生物和底栖生物产量增加的地区。我们比较了滩顶和南侧潮汐混合锋面上的浮游动物，因为美国-GLOBEC在1994-1996年间进行的研究表明，尽管Finmarchicus无节幼体在季节早期平流到滩顶，但随后没有形成强大的群体，这可能是该地区强烈捕食压力的结果。无节幼体和桡足类的摄食率将在船上使用天然猎物组合的实验中直接测量。杂食性摄食的直接影响将在就地捕食场和物理状况的背景下进行解释。最终，将在其他研究人员对消费者分布、状况、生活史参数和生产的测量的背景下，合作解决消费者饮食中植物与动物猎物的影响。