Spring Chlorophyll Concentrations on the Eastern Bering Sea Shelf

The eastern Bering Sea shelf supports productive marine ecosystems with extraordinarily valuable fisheries and subsistence resources, but sub-arctic seas are predicted to be one of the regions most sensitive to future warming of the world's oceans. Some of the most direct effects of changing climate will be on the extent, duration and timing of sea-ice over the Bering Sea shelf. Sea-ice controls the timing of the spring phytoplankton bloom, the fate of primary production, water column temperature and salinity, and provides a haul out and molting platform for marine mammals. Thus, the most urgent priority of the Bering Sea Ecosystem Study (BEST) is to examine the role of changing sea-ice conditions on the chemical, physical, and biological characteristics of the ecosystem. The first BEST cruise was scheduled on the US Coast Guard Cutter Healy in April-May 2007, however, physical observations, water column nutrient chemistry, and zooplankton distribution / abundance were not among the ecosystem components funded in the first call for proposals. Project ARC-0722448 funded by NSF after the first call for BEST proposals filled this gap in chlorophyll collections until the remainder of BEST projects could be assembled in 2008.白令海东部陆架支撑着生产力极为旺盛的海洋生态系统，拥有兼具经济与生计价值的宝贵渔业资源；而副极地海域被预测为全球海洋未来变暖影响最敏感的区域之一。气候变化带来的最直接影响之一，将体现在白令海陆架海冰的范围、持续时长与暴发时机上。海冰不仅调控春季浮游植物水华的暴发时机、初级生产力的分配格局、水体的温度与盐度，还为海洋哺乳动物提供了休憩栖息与蜕皮换毛的平台。因此，白令海生态系统研究（Bering Sea Ecosystem Study, BEST）的首要紧迫任务，便是探究海冰条件变化对该生态系统化学、物理与生物学特征的调控机制。首次BEST科考航次原定于2007年4至5月在美国海岸警卫队“希利”号（US Coast Guard Cutter Healy）破冰船上执行，但首次提案征集阶段获批资助的生态研究组分中，并未涵盖物理观测、水体营养盐化学以及浮游动物分布与丰度相关研究内容。在首次BEST提案征集结束后，由美国国家科学基金会（National Science Foundation, NSF）资助的ARC-0722448项目填补了叶绿素数据采集的研究空白，直至2008年其余BEST研究项目得以整合完成。