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

雪燕，Pagadroma nivea，是一种丰富的海鸟物种，只出现在南大洋覆盖着冰层的海域，在不结冰的纳塔克的距骨斜坡上筑巢。研究表明，在一些不结冰的地方，这种物种已经筑巢了35,000年。拟议的项目将侧重于对距今10,000年前的雪燕‘mumiyo’(即聚集在巢穴周围的胃油)的层状沉积物进行同位素分析。样本在手中，是在东南极的邦格山采集的。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。雪燕以一个营养级别的磷虾为食，或者以下一个营养级别的鱼为食。因此，结果可能揭示饮食中的长期变化作为这两类猎物可获得性的函数。这些猎物对雪燕的可获得性反过来又被已知受到海冰覆盖变化的影响。海冰覆盖范围随着气候的变化而变化，南极洲沿岸的沉积物岩心揭示了这一点。拟议的分析有可能揭示食物网中高等物种的相应变化。

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.