Marine ecosystem response to late Pleistocene climate conditions- evidence from snow petrel stomach oil deposits ("mumiyo") in East Antarctica

在最后一次冰川盛期期间，南极大陆周围的冰架和海冰扩大，影响了全球温盐环流和南极特有的生物群。在这些冰川条件下，沿海冰川已被确定为南极底水形成的重要地点和海洋生物的冰川避难所。关于在Dronning Maud陆地(东南极洲)附近存在这种多尼龙的知识来自于雪燕的内陆繁殖地。过去的雪燕群落的记录是形成在巢前的胃油沉积(Mumiyo)。放射性碳测年显示，这些鸟类至少在过去60ka期间占据了目前无冰的山脉，这不仅意味着没有冰川的陆地地区，而且还表明存在海冰减少的海洋觅食地，因此多尼雅。在拟议的项目中，我们希望使用东南极不同地区的木米尤矿藏来详细重建海洋和陆地环境条件。我们建议用地球化学、古生物学和同位素指标来检测冰期和全新世条件下雪燕可利用的食物资源、沿海地区的海冰以及雪燕陆地繁殖栖息地的条件的变化。这将有助于更好地了解生物地球化学循环、食物网络结构以及海洋生态系统对冰川气候条件的反应。

During the Last Glacial Maximum (LGM) expanded ice shelves and sea ice around the Antarctic continent affected global thermohaline circulation as well as endemic Antarctic biota. Under these glacial conditions coastal polynyas have been identified as important sites of Antarctic Bottom Water formation and as glacial refuges for marine biota. Knowledge about the existence of such polynyas off Dronning Maud Land (East Antarctica) comes from the in-land breeding sites of snow petrels. Records of past snow petrel colonies are stomach oil deposits (mumiyo), which form in front of the nests. Radiocarbon dating showed that the birds occupied the presently ice-free mountain ranges at least during the past 60 ka, which does not only imply un-glaciated terrestrial areas, but also points to the existence of marine feeding grounds with reduced sea ice, hence polynyas. In the proposed project we want use mumiyo deposits from different regions in East Antarctica for detailed reconstructions of marine and terrestrial environmental conditions. We suggest geochemical, paleontological and isotopic proxies to detect changes in the available food resources for snow petrels, in sea ice in coastal regions and in conditions at the terrestrial breeding habitat of snow petrels under glacial and Holocene conditions. This will lead to a better understanding of biogeochemical cycles, food web structure and the response of marine ecosystems to glacial climate conditions.