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

雪海燕，Pagadroma nivea，是一种数量丰富的海鸟，只出现在南大洋的浮冰覆盖的海洋中，并在无冰的纳纳塔克的talus斜坡上筑巢。研究表明，在一些无冰的地方，这种物种已经筑巢了35000年。拟议中的项目将重点分析距今1万年的雪海燕“mumiyo”（即积聚在筑巢腔周围的胃油）层状沉积物的同位素。这些样本是在南极洲东部的彭格山收集的。这些分析将评估南大洋上层食物网某些部分的结构随气候变化的变化。将分析18O和2H的剖面，以揭示与海洋气候长期波动的对应关系，而13C和15N将用于评估食物网的波动。雪海燕吃磷虾，在一个营养水平，或鱼，在下一个营养水平。因此，结果可能揭示了饮食的长期变化是这两类猎物可用性的函数。雪海燕的这些猎物的可用性反过来又受到海冰覆盖变化的影响。南极沿海沉积物岩心显示，海冰覆盖随着气候变化而变化。提出的分析有可能揭示食物网中更高层次的相应变化。

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.