A Collaborative Proposal on Particle Dynamics in an Arctic Ecosystem: Role of Enzymatic Hydrolysis in Carbon Export

这项研究提案是国际北水(NOW)Polynya项目的组成部分，该项目是加拿大牵头的一项努力，目的是描述冰盖覆盖的巴芬湾北部的开阔水域生态系统。该地区具有重大的地缘政治利益，因为该地区有商业渔业、通往北极的航运通道，以及当地因纽特人的利益，他们现在依靠非同寻常的生物生产谋生。同样引起科学关注的是从该系统出口的远洋初级生产力的命运：即下沉的颗粒材料是否仍可用于支持更高的营养水平，还是在深海以微生物的方式循环利用。这项研究旨在检验寒冷温度限制水中微生物活动的假设；它还检验了特定的酶反应，作为在流场的背景下，覆盖生态系统的自养和异养性质的预测指标。PIS将在1997年和19998夏季通过部署粒子传感器和收集器的组合来测试这些和其他问题。这些将包括固定在海流计系泊设备上的长期泥沙捕集器、透射率测量、大颗粒的现场摄像评估以及船上沉降柱收集。

This research proposal is an integral component of the international North Water (NOW) polynya project, a Canadian led effort to characterize the open-water ecosystem in the northern portion of ice-covered Baffin Bay. The region is of significant geopolitical interest due to commercial fisheries, shipping access to the Arctic, and to the native Inuit people who depend upon the extraordinary biological production in the NOW for their livelihood. Of parallel scientific interest is the fate of pelagic primary production exported from the system: i.e., whether sinking particulate materials remain available to support higher trophic levels or are recycled microbially at depth. This research is designed to test the hypothesis that cold temperature limits midwater microbial activities; it also examines specific enzymatic responses as predictive indicators of the autotrophic versus heterotrophic nature of the overlying ecosystem, within the context of the flow field. The PIs will test these and other questions by deploying a combination of particle sensors and collectors throughout NOW in the summers of 1997 and 19998. These will include long-term sediment traps secured to current-meter moorings, transmissometry measurements, in situ camera assessments of large-particles, and shipboard settling-column collections.