Seasonal Ice Cover and its Impact on the Epipelagic Community in the Northwestern Weddell Sea: Long Time-Series Monitoring

南大洋浮冰每年的扩张和退缩是世界海洋中最大的季节性过程。这种冰盖的季节性迁移对海洋水柱100米以上的远洋生物群落产生了深远的影响，这是冰盖与海鸟和哺乳动物等顶端捕食者相互作用最强烈的地方。这种独特的远洋生物群落主要是通过船舶作业来研究的。然而，对浮冰下的上层海洋群落进行船上取样存在着公认的问题，并且需要对该群落进行足够长的时间尺度的监测，以检查该环境的极端时间变异性。为了检查连续的时间变化，该项目将开发一个垂直剖面泵采样器，用于收集威德尔海浮冰下可编程深度间隔的浮游动物和微浮游动物。一旦开发完成并进行现场测试，该仪器将与之前开发的向上、垂直剖面声学阵列同时部署，为期一年。该联合系泊项目将监测在一年中有7-8个月被冰覆盖的地区水柱上方100米的浮游动物和微浮游动物的垂直分布、丰度和大小频率。该项目还将包括在一年的实地研究过程中进行三次季节性船上采样。这些长期系泊阵列的成功部署和现场数据的检索将有助于更好地了解南大洋浮冰下上层海洋群落的功能。这是极地项目办公室和海洋科学部联合发起的一个项目。＊＊＊

9315029 Smith The annual expansion and retreat of pack ice in the Southern Ocean are the largest seasonal processes in the World Ocean. This seasonal migration of the ice cover has a profound impact on the pelagic community in the upper 100 m of the oceanic water column where the interactions between ice cover and apex predators, such as seabirds and mammals, are most intense. This unique pelagic community has been mainly studied with ship-based operations. However, there are well recognized problems associated with shipboard sampling of the epipelagic community under pack ice and the need to monitor this community on long-time scales sufficient to examine the extreme temporal variability of this environment. To examine continuous temporal variability, the project will develop a vertically-profiling pump sampler for the collections of zooplankton and micronekton over programmable depth intervals under pack ice in the Weddell Sea. Once developed and field tested, this instrument will be deployed concurrently with previously developed upward-looking, vertically-profiling acoustic arrays for a period of one year. The combined mooring project will monitor the vertical distribution, abundance and size frequency of acoustically detectable zooplankton and micronekton in the upper 100 m of the water column in an area that experiences ice cover during 7-8 months of the year. This project will also include seasonal shipboard sampling on three cruises over the course of the one year field study. A successful deployment of these long-term mooring arrays and retrieval of data from the field will contribute to a greater understanding of how epipelagic communities function under pack ice in the Southern Ocean. This is a jointly sponsored project of the Office of Polar Programs and the Division of Ocean Sciences. ***