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-全球：跨锋面过程和招聘的变化乔治银行-饮食的哲水蚤finmarchicus桡足类和无节幼体这个程序将检查控制海洋动物的分布和丰富的时间和空间的生物和物理过程，特别是与跨锋面过程。 该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银行目标桡足类种群招募的贡献。 我们假设，桡足类和无节幼体位于额叶区域和混合良好（银行）一侧的战线经验丰富的食物环境相对于分层（银行外）一侧的战线。 我们将首先通过水文调查来确定前沿，其中包括对纳米和微型浮游生物（即大小为2-200微米的植物和动物猎物）猎物场进行CTD/玫瑰花结取样，我们在GLOBEC西北大西洋计划第1和第2阶段的研究已经证明，目标桡足类和仔鱼大量利用了这些猎物场。 将对这些生物的交换率进行评价，并与来自相同水文模型的保守水柱特性的交换率进行比较。 我们将评估捕食场，并测量两个不同季节特有的两个交叉锋面区域中桡足类和哲水蚤类桡足类的摄食无节幼体阶段对微型和微型浮游生物的消耗：（1）东北峰前，在2 - 3月表现出最强的地表热信号;在春末和夏季（5月下旬至8月），潮汐混合锋将河岸顶部的沃茨与南侧分开。 我们专注于C finmarchicus，因为这个物种占主导地位的乔治银行在1月至6月期间的浮游动物生物量。 我们强调东北峰和南翼的锋面，因为这些是水，营养物质和浮游生物到银行的跨锋面运输的潜在场所。 我们关注东北峰，因为相对于银行的其他部分，它是浮游生物和底栖生物产量增加的区域。 我们比较了浅滩顶部和南部侧翼之间潮汐混合前沿的浮游动物，因为美国- 1994-1996年期间进行的GLOBEC研究表明，虽然C. finmarchicus无节幼体平流到银行波峰在本赛季初，强大的队列不随后发展，可能是由于在这方面的强烈捕食压力。 摄食率的无节幼体和桡足类将直接测量在船上实验使用自然猎物组合。 杂食性喂养的近端影响将被解释在原位猎物领域和物理制度的背景下。 最终，消费者饮食中的植物与动物猎物的影响将在其他消费者分布，条件，生活史参数和生产的调查人员进行测量的背景下合作解决。