Collaborative Proposal: Cross-Shelf Transport and Post-Bloom New Production Near the Pribilof Islands

合作提案：普里比洛夫群岛附近的跨货架运输和花后新生产

• 批准号: 0326953
• 负责人: Raymond Sambrotto
• 金额: $ 11.98万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0326953&HistoricalAwards=false
• 关键词: Collaborative; Proposal; Cross; Shelf; Transport

The proposed study will test the hypothesis that on-shelf flow of nutrient- and zooplankton-rich slope water influences post-spring-bloom new production and zooplankton populations in the vicinity of the Pribilof Islands, thereby enhancing the region's ability to support juvenile fish and planktivorous seabirds. The project will investigate on-shelf transport of slope water, which supplies nutrients that sustain new primary production in summer, a season when the availability of new production on the shelf is limited by stratification. A second hypothesis is that this new production will be dominated by diatoms rather than by flagellates, and a diatom-based food web will result in meso-zooplankton with a greater energy content than meso-zooplankton in a flagellate-based food web. These energy-rich zooplankton are expected to be of greater value to juvenile fish and planktivorous seabirds than those that have fed upon less lipid-rich phytoplankton. The project will also test these hypotheses during July/August cruises in 2004 to 2007. During these cruises, the PIs will compare production and its fate in an area on the middle shelf where summer-time cross-shelf advection is weak (Mooring 2), on the middle shelf in an area of episodic advection but little vertical mixing (Mooring 4) and at the Pribilof Islands where there is both on-shelf transport and tidal mixing of nutrients into the upper mixed layer. The project will measure along- and across-shelf flows (Stabeno, PMEL), nutrient concentrations (Mordy, UW/PMEL), standing stocks of phytoplankton (Zeeman, U. New England), new, regenerated and total production (Zeeman, Sambrotto, Lamont-Doherty), the grazing rates of micro-zooplankton in relation to phytoplankton standing stocks and production (Strom, Western Washington University), zooplankton biomass and composition (Coyle, U. Alaska, Fairbanks), lipid content, fatty-acid composition, and stable isotope signatures of zooplankton, juvenile fish and seabirds (Napp, NMFS), and the foraging distributions and food habits of marine birds (Hunt, U. California, Irvine). In addition, the project will use satellite-tracked drifters and moorings to measure currents. This proposal is the first in the Bering Sea to address the effect of on-shelf fluxes of nutrient-rich slope water on post-spring-bloom new production, and in turn, how this new production affects the abundance and quality of prey for juvenile fish (i.e., age-0 walleye pollock) and planktivorous seabirds. Post-bloom new production may be particularly important for providing high quality prey at a time when juvenile fish are developing the reserves to carry them through the winter and seabirds are feeding growing young. The work focuses on a region of great economic and societal importance, and examines the ecological processes that affect the productivity of Pribilof Islands' waters and their ability to support juvenile fish, and the seabirds and marine mammals that depend on them. The most abundant fish in the area are juvenile walleye pollock, the target of the world's largest single-species fishery. The information generated by the proposed research will be of value in assessing the mechanisms whereby global climate change can affect the amount of post- spring bloom new production and the nutritional quality of prey available to upper trophic levels. The project will include undergraduate, graduate and post-doctoral students in the field and in the laboratory for the analysis and workup of the data and will strive to develop outreach programs with the school systems on St Paul and St. George Islands. The work will be disseminated in the refereed literature and through web sites.

拟议的研究将测试这一假设，即在货架上流动的营养和丰富的浮游动物的斜坡水影响后春季开花的新产品和浮游动物种群在附近的Pribilof群岛，从而提高该地区的能力，以支持幼鱼和食虫海鸟。该项目将调查陆坡水的大陆架运输，陆坡水在夏季提供维持新的初级生产的营养物质，而在夏季，大陆架上新生产的可用性受到分层的限制。第二个假设是，这种新的生产将占主导地位的硅藻，而不是鞭毛虫，和一个以藻类为基础的食物网将导致中型浮游动物具有更大的能量含量比中型浮游动物在一个以鞭毛虫为基础的食物网。这些富含能量的浮游动物预计对幼鱼和食肉海鸟的价值要大于那些以富含脂质的浮游植物为食的浮游动物。该项目还将在2004年至2007年7月/8月的航行中检验这些假设。在这些巡航期间，PI将比较夏季跨大陆架平流较弱的中大陆架区域（系泊2）、有间歇性平流但垂直混合较少的中大陆架区域（系泊4）以及有大陆架输送和潮汐混合的营养物质进入上混合层的普里比洛夫群岛的生产及其命运。该项目将测量沿着和跨大陆架流动（Stabeno，PMEL）、营养物浓度（莫迪，UW/PMEL）、浮游植物现存量（Zeeman，U。新英格兰）、新的、再生的和总的生产量（Zeeman，Sambrotto，Lamont-Doherty）、微型浮游动物相对于浮游植物现存量和生产量的摄食率（Strom，Western华盛顿大学）、浮游动物生物量和组成（Coyle，U.阿拉斯加，费尔班克斯），浮游动物，幼鱼和海鸟的脂质含量，脂肪酸组成和稳定同位素特征（Napp，NMFS），以及海鸟的觅食分布和食物习惯（Hunt，U。加州，欧文）。此外，该项目还将使用卫星跟踪的漂流物和系泊设备来测量海流。这是白令海第一个解决富含营养物的斜坡水的货架通量对春季开花后新生产的影响，以及这种新生产如何影响幼鱼猎物的丰度和质量（即，0岁的狭鳕）和食草海鸟。当幼鱼正在发展储备以携带它们过冬，海鸟正在喂养成长中的幼鱼时，开花后的新产量可能对提供高质量的猎物特别重要。这项工作的重点是一个具有重大经济和社会意义的区域，并审查影响普里比洛夫群岛沃茨生产力及其供养幼鱼、海鸟和海洋哺乳动物的能力的生态过程。该地区最丰富的鱼类是青少年大眼鳕，世界上最大的单一物种渔业的目标。拟议的研究所产生的信息将有助于评估全球气候变化可能影响春季开花后新产量和上层营养级猎物营养质量的机制。该项目将包括在实地和实验室分析和整理数据的本科生、研究生和博士后学生，并将努力与圣保罗和圣乔治群岛的学校系统制定推广方案。这项工作将通过参考文献和网站传播。