Collaborative: Snow Petrel Mumiyo: A Record of Food-Web Variability During the Holocene

雪海燕，Pagadroma nivea，是一种丰富的海鸟物种，只出现在南大洋的浮冰覆盖的海洋中，并在无冰的纳纳塔峰的岩屑坡中筑巢。 研究表明，在一些无冰的地方，这个物种已经筑巢了35,000年。 拟议的项目将侧重于对雪海燕“mumiyo”（即，胃里的油脂会聚集在筑巢的洞穴周围）可以追溯到距今1万年前。 这些样本是在东南极洲的邦格山采集的。 这些分析将评估南大洋上层食物网某些部分的结构因气候变化而发生的变化。 将分析18 O和2 H的剖面，以揭示海洋气候长期波动的对应关系，而13 C和15 N将用于评估食物网波动。 雪海燕以一个营养级的磷虾或下一个营养级的鱼类为食。 因此，结果可能会揭示长期的开关在饮食中的功能，在这两类猎物的可用性。 这些猎物对雪海燕的可用性反过来又受到海冰覆盖变化的影响。 海冰覆盖率随气候变化而变化，正如南极洲沿海沉积物岩心所显示的那样。 拟议的分析有可能揭示相应的变化，更高的食物网。

The Snow Petrel, Pagadroma nivea, is an abundant seabird species that occurs only in pack-ice covered seas of the Southern Ocean and nests among talus slopes of ice-free nanataks. It has been shown that at some ice-free locations this species has nested for 35,000 years. The proposed project will focus on the isotopic analysis of laminated deposits of Snow Petrel 'mumiyo' (i.e., stomach oil that accumulates around nesting cavities) dating back 10,000 years before present. The samples are in hand and were collected at the Bunger Hills, East Antarctica. These analyses will assess the variation in the structure of certain portions of the upper food web of the Southern Ocean in response to climate variation. Profiles of 18O and 2H will be analyzed to reveal correspondence to long-term fluctuations in marine climate, while 13C and 15N will be used to assess food web fluctuations. The Snow Petrel feeds on either krill, at one trophic level, or fish, at the next highest. Thus results may reveal long-term switches in diet as a function of availability in these two classes of prey. Availability of these prey to Snow Petrels is in turn known to be affected by the variation in sea ice cover. Sea ice cover varies with climate, as revealed in sediment cores of coastal Antarctica. The proposed analyses have the potential to reveal corresponding changes in higher in the food web.