Collaborative Research: BEST: Mesozooplankton-microbial food web interactions in a climatically changing sea ice environment

SERR 0732301俄勒冈州立大学提供的基金用于分析海冰变化对浮游食物网结构的影响，重点是微型浮游动物和中游浮游动物的营养联系以及白令海春季海冰条件下浮游植物水华的命运。为此，首席调查人员计划在一系列冰、冰缘和开阔水域条件下进行实验，特别是将考虑分离的冰藻在存在时作为二级消费者的食物来源的重要性。作为这项工作的一部分，他们将确定浮游植物、微型浮游动物和中型浮游动物组合的现存量、组成和大小结构，测量微型浮游动物的生长和中型浮游动物的繁殖率，并测量异养原生动物和中游动物的捕食率和捕食偏好。它们还将确定浮游生物的细微垂直分布，特别是浮游植物等脆弱形式的垂直分布，以确定与水文特征有关的浮游生物/颗粒的薄层。他们的合作研究将明确解决以前在亚北极这一地区从未探索过的营养联系。他们假设，由于全球变暖而改变的生态系统结构，例如季节性海冰的减少，将改变这些营养相互作用，从而改变该地区藻类生产的最终命运。他们计划参加在最佳野外计划期间为春季海冰条件提出的三次年度巡航。他们将在最佳研究区域内的横断面上的指定站点进行全套分析(标准蓄积量测定和速率测量)。丰度和速率措施将结合起来，以确定相对微型浮游动物和中游动物的放牧影响。虽然从该计划获得的直接测量和观测将使主要调查人员能够描述东白令海陆架的微型浮游动物和中游动物及其捕食影响的细节，但他们获得的数字也将对将作为最佳实践的一部分开发的生态系统模型提供强有力的约束。在综合最佳调查员得出的集体理解的过程中，这些模型将成为一个重要的工具。

Sherr 0732301Oregon State UniversityFunds are provided for an analysis of the impact of changing sea ice conditions on planktonic food web structure, focusing on microzooplankton and mesozooplankton trophic linkages and the fate of phytoplankton blooms in the Bering Sea during spring sea ice conditions. To this end, the principal investigators plan to conduct experiments over a range of ice, ice edge, and open water conditions, and, particularly, will consider the importance of detached ice algae, when present, as a food source for the secondary consumers. As part of this effort, they will determine standing stock biomass, composition, and size structures of phytoplankton, microzooplankton and mesozooplankton assemblages, measure microzooplankton growth and mesozooplankton reproduction rates, and measure grazing rates and prey preferences of heterotrophic protists and dominant species of mesozooplankton. They will also determine the fine scale vertical distribution of plankton, especially of fragile forms such as colonial phytoplankton, to identify thin layers of plankton/ particles in association with hydrographic features. Their collaborative study will explicitly address trophic linkages previously unexplored in this region of the subarctic. They hypothesize that changing ecosystem structure due to global warming, e.g. decrease in seasonal sea ice, will alter these trophic interactions, and thus the ultimate fates of algal production in this region. They plan to participate in each of the three annual cruises proposed for spring sea-ice conditions during the BEST field program. They will carry out a full set of analyses (standing stock determinations and rate measurements) at designated stations along transects within the BEST study area. Abundances and rate measures will be combined to determine relative microzooplankton and mesozooplankton grazing impacts. While the direct measurements and observations to be derived from this program will allow the principal investigators to describe the microzooplankton and mesozooplankton of the eastern Bering Sea shelf and their grazing impacts with a detail heretofore unavailable, the numbers they derive will also provide strong constraints on the ecosystem models to be developed as part of BEST. These models will serve as an important tool during the synthesis of the collective understanding derived by the BEST investigators.