Variability of export flux in polynya regions of the Canadian Arctic coastal waters

在2003-2004年加拿大北极大陆架运输研究项目期间，利用时间序列沉积物捕集器在麦肯齐大陆架斜坡和阿蒙森湾水域观测了向下颗粒通量的区域和时间变化。本研究的目的是：1. 通过1987-1988年和2003-2004年的对比，了解本地和外来有机粒子的贡献及其年代际变化。2. 了解生物通量的区域和季节变化规律，以及主要的通量调节过程。3. 为了寻找食物网的指示生物，通过比较1987-1988年和2003-2004年收集的游泳者成分的变化。得到的结果是；1. 2003-2004年，陆源年POC通量对总POC通量的贡献在4%至49%之间，与1987-1988年大致相同。2. 生物源通量具有不同的区域和季节特征，并可能受到与海冰浓度相关的食物网结构的调节。3. 大型微食性动物，如翼足类动物，可能表明食物网的变化是对海冰浓度减少（全球变暖？）的响应。浮游动物游泳者（总长度为100 ~ 1mm）组成和丰度的季节变化，数量上桡足类为优势，片足类、介形虫类和多毛类数量较少。夏季桡足类中，长足类（Metridia longus）和大角足类（Calanus hyperboreus）的数量较多，而冰原毛纲（Pereuchaeta glacialis）的数量相对较多。利用时间平均丰度和泳者组成的聚类分析表明，夏季各站点的泳者组成不同于其他季节，冬季与CAI8（400米）的泳者组成相似，表明该海域浮游动物群落具有季节性的垂直和水平迁移。在小型浮游动物（桡足类、Oncaea类、Oithona类和Metridia类）中，桡足类以nauplii类为主，且有季节变化。3个站点早春采集的鹦鹉螺体长约190 μ m。如果这些捕获的鹦鹉螺桡足类确实在捕集器深度内及其周围有生物居住，它们在孵化后的早春停留在200米左右的地层，然后随着它们在春夏的生长向上迁移到表层。少

Regional and temporal variability of downward particle flux using time-series sediment traps were observed in waters of the Mackenzie Shelf slope and the Amundsen Gulf during the CASES (Canadian Arctic Shelf Transport Study) Project in 2003-2004. Objectives Of the present study are; 1. To know the contribution of both autochthonous and allochthonous organic particles and the decadal change through a comparison between 1987-1988 and 2003-2004. 2. To know how to vary biogenic fluxes regionally and seasonally and what are the major flux-mediating processes. 3. To find indicator organisms of food web, change through a comparison of collected swimmer compositions between 1987-1988 and 2003-2004. Results obtained were; 1. Contribution of annual terrigenous POC flux ranged from 4 to 49% of total POC flux through a year of 2003-2004, which was approximately the same as that in 1987-1988. 2. The biogenic flux varied regionally and seasonally, and the fluxes could be mediated by the food web str … More ucture associated with sea ice concentration. 3. Large microphagous aminals, such as pteropods, may be indicative of food web change in response to the decrease of sea ice concentration (global warming?).As for the seasonal variation of compositions and abundances of zooplankton swimmers (>1mm in total length), copepods were the dominant component numerically, and Amphipoda, Ostracoda and Polychaeta were the less abundant zooplankton taxa. Among the copepods, Metridia longa and Calanus hyperboreus were usually much abundant and Pereuchaeta glacialis was relatively abundant in summer ZooplanIcton taxonomic composition varied temporally and spatially. Agglomerative hierarchical cluster analysis using time-averaged abundance and compositions of swimmers showed that compositions at all stations in summer were different from those in other seasons, and similar to that at CAI8 (400m) in winter, suggesting the seasonal vertical and horizontal migration of zooplankton community around this sea areas.Among small-sized zooplankton (copepod nauplii, Oncaea spp, Oithona spp and Metridia spp,), copepod nauplii occurred predominantly and varied seasonally. Their body length of the nauplii collected in early spring were about 190 um in three stations. If these trap-collected copepod nauplii were really inhabited in and around the trap depth, they stayed at about 200m layer in early spring after their hatching, and then migrated upward to the surface layers as they grew in spring to summer. Less