The organic carbon flux to Arctic margin sediments: redox tracers stable isotopes and biomarkers as proxies for change

To date, sediment cores have been successfully collected, while aboard the CCGS Sir Wilfrid Laurier in July 2007, and the CCGS Louis S. St. Laurent in July, 2009. The suite of cores spans the continental shelf and slope at depths varying from 60 to 2000 m from the Bering and Chukchi Seas, to Barrow Canyon, to the Mackenzie Shelf, Davis Strait, Baffin Bay and Canadian Archipelago. The analysis of the samples is now completed and we are now working on the interpretation of results. There is a lot that can be learned from the sediment cores. So far, the results show strong differences in the sediments and organic carbon between different regions of the Arctic. Areas that are very productive with algae and the marine food web, like the North Water Polynya in northern Baffin Bay, have very different organic carbon cycles from areas near river mouths that are strongly influenced by the land. We plan to characterize each region in detail and also compare the regions to produce an overall picture of the organic carbon cycle in the Canadian Arctic continental margin. We will also identify if the organic carbon cycle has been affected by the climate-related changes already underway.of climate change.截至目前，研究团队已成功获取沉积物岩芯：2007年7月搭载于CCGS Sir Wilfrid Laurier号科考船采集，2009年7月搭载于CCGS Louis S. St. Laurent号科考船采集。本次获取的整套岩芯覆盖了从白令海、楚科奇海至巴罗峡谷，再到麦肯齐大陆架、戴维斯海峡、巴芬湾及加拿大北极群岛的大陆架与陆坡区域，采样水深跨度为60米至2000米。目前样品分析工作已全部完成，团队正致力于研究结果的解译工作。沉积物岩芯可提供大量关键科研信息，截至当前的初步结果显示，北极不同区域的沉积物与有机碳特征存在显著差异。诸如巴芬湾北部的北水冰间湖（North Water Polynya）这类藻类与海洋食物网极为繁盛的区域，其有机碳循环模式与受陆地强烈影响的河口附近区域存在显著不同。本团队计划对每个区域开展详细的特征表征，并通过区域间对比，完整勾勒加拿大北极大陆边缘的有机碳循环整体图景。此外，本团队还将甄别当前已在发生的、与气候变化相关的各类改变是否对有机碳循环造成了影响。