Distribution, Biomass and Ecological Role of Macrozooplankton and Fishes in the Arabian Sea and Equatorial Indian Ocean

这个项目的目标是确定阿拉伯海大型浮游动物和鱼类的丰度和分布，并估计它们对这些环境中有机质垂直通量的贡献。受季风影响的阿拉伯海生态系统是世界上最具生产力的生态系统之一，但在生产和沉积方面存在明显的季节性差异。该系统在其动物群的分布和比较方面，以及在地表生产分布到水柱和海底的途径方面都是不寻常的。索马里沿海上升流区是一个支持高生物量、低多样性远洋动物群的生产区域，而赤道印度洋是一个典型的低营养带，拥有高度多样性的未知物种。在这些截然不同的制度下，关于大型生物的排泄和垂直迁移等过程在调节物质垂直通量方面的作用，仍有许多问题有待回答。研究的具体目标包括：1)确定大型浮游动物和鱼类的分布和丰度；2)确定浮游动物和鱼类垂直迁移的范围和时间；3)大型浮游动物胃内容物及消化率的检测与定量；4)利用拖网采集的数据为其他研究者同时进行的声学采样提供真值校准；5)阿拉伯海和邻近赤道印度洋大型浮游动物和鱼类的物种多样性和动物地理学分析。我们的研究结果将有助于了解阿拉伯海和印度洋中上层生态系统的群落结构和营养动态。这些巡航将与JGOFS的两次远洋过程巡航同时进行，我们的数据将与JGOFS测量和了解阿拉伯海垂直通量的目标有关。

9423443 Kremer The goal of this project is to determine the abundance and distribution of macrozooplankton and fishes in the Arabia Sea, and to estimate their contribution to the vertical flux of organic matter in these environments. The monsoonally forced Arabian Sea ecosystem is one of the most productive in the world, but with sharp, seasonal contrasts in production and sedimentation. The system is unusual in the distribution and comparison of its fauna, and in the pathways by which surface production is distributed into the water column and sea floor. The Somali coastal upwelling zone is a productive region supporting a high-biomass, low- diversity pelagic fauna, and the equatorial Indian Ocean is a typical oligotrophic zone uith a high diversity of inadequately known species. Many questions remain to be answered on the role of such processes as egestion and diel vertical migration of large organisms in regulating vertical fluxes of material in these contrasting regimes. Specific objectives of the study include: 1) determination of distribution and abundance of macrozooplankton and fishes; 2) determination of the extent and timing of diel vertical migration of zooplankton and fish; 3) examination and quantification of stomach contents and egestion rates of macrozooplankton; 4) use of trawl collections to provide ground-truth calibration of concurrent acoustic sampling by other investigators; and 5) analysis of the species diversity and zoogeography of macrozooplankton and fishes in the Arabian Sea and adjacent equatorial Indian Ocean. Our results will contribute to understanding community structure and trophic dynamics in the Arabian Sea and Indian Ocean pelagic ecosystems. The cruises will be concurrent with two of the JGOFS Pelagic Process cruises, and our data will bear on JGOFS objectives of measuring and understanding vertical fluxes in the Arabian Sea .