The Antarctic Ice Edge Bloom: Its Importance to Intermediate Trophic Levels

南极冰缘作为一个锋面系统，对不同的营养水平有不同的影响。在夏季，初级生产者和微异养生物在融化的水透镜体中繁殖，这些水透镜体是在退缩的冰边缘的光区形成的。相比之下，对于一代时间为一年或一年以上的寿命较长的消费物种，冰边缘的任何增加的常备库存都必须是迁移到冰边缘或在当地生产的结果。这项研究将验证这样一种假设，即夏季冰缘水华作为一种生物磁铁，集中了后生动物的消费者，并作为一种向南移动的发电机，促进了浮游动物物种的生长和繁殖。在南部夏季的斯科舍-威德尔海地区进行的研究将重点关注研究区开放水域、边缘冰区和浮冰区水柱上1000米浮游动物和微浮游生物的分布、丰度和生物活性。将描述物理环境；将利用体内荧光绘制冰缘浮游植物繁殖的范围和活动，并对初级产量进行估计。浮游动物/微浮游生物群落结构将利用光学浮游生物采样器以及渔网和拖网的数据进行表征。浮游动物的生物活性将通过代谢率、放牧率、产蛋率、饮食和代谢酶活性的研究来评估。所得数据将描述研究区浮游动物/微浮游动物群落结构、主要营养关系、放牧影响和能量利用模式，清楚地显示冰缘水华对中间营养水平的影响。

The Antarctic ice edge as a frontal system has different implications for different trophic levels. During summer, primary producers and microheterotrophs flourish in the meltwater lens that is created in the euphotic zone at the retreating ice edge. In contrast, for longer-lived consumer species with generation times of a year or more, any enhanced standing stocks at the ice edge must be the result of immigration to the ice edge or production in place. This research will test the hypothesis that the summer ice edge bloom acts as a biological magnet to concentrate metazoan consumers and as a southward moving generator facilitating growth and reproduction in zooplankton species. Research conducted in the Scotia-Weddell Sea region during the austral summer will focus on the distribution, abundance, and biological activity of zooplankton and micronekton in the upper 1000m of the water column in the open water, marginal ice zone, and pack ice regions of the study area. The physical environment will be described; the extent and activity of the ice edge phytoplankton bloom will be mapped using in vivo fluourescence and estimates of primary production will be made. Zooplankton/micronekton community structure will be characterized using data from an optical plankton sampler, as well as nets and trawls. Biological activity of zooplankton will be evaluated through studies of metabolic rate, grazing rate, egg production rate, diet, and metabolic enzyme activity. The resultant data will describe zooplankton/micronekton community structure, major trophic relationships, grazing impact, and patterns of energy utilization for species living in the study area, showing clearly the impact of the ice edge bloom on the intermediate trophic levels.