A preliminary record of the historical seabird population in the Larsemann Hills, East Antarctica, from geochemical analyses of Mochou Lake sediments
A preliminary record of the historical seabird population in the Larsemann Hills, East Antarctica, from geochemical analyses of Mochou Lake sediments
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通过对莫愁湖沉积物的地球化学分析，初步记录了东南极洲拉斯曼山历史上的海鸟种群
DOI：
10.1080/03009480600991789
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发表时间：
2007-04-01
期刊：
影响因子：
2.2
通讯作者：
Wang, Yuhong
中科院分区：
文献类型：
--
作者：
Liu, Xiaodong;Sun, Liguang;Wang, Yuhong
对来自东南极洲拉斯曼山镜半岛莫愁湖的 85 厘米长的沉积物序列进行了元素地球化学、生物地球化学以及酸不溶性和酸溶性组分中的锶 (Sr) 同位素组成的研究。生物地球化学数据表明，淡水湖相沉积物起源于距今2750年后。元素Zn、Cu、F、P和Se通量表现出几乎相同的垂直分布模式，并且它们与烧失量的比率彼此之间具有很强的正相关性，表明共同的来源，可能来自海鸟粪便。 Sr同位素组成进一步证明了海鸟对淡水湖沉积物的影响。酸溶部分中测定的 Sr-87/(86)Sr 比值明显低于酸不溶部分中的 Sr-87/(86)Sr 比值；它们具有基岩 Sr-87/(86) Sr 特征，与海洋来源的 Sr 特征接近，并且与总氨基酸呈负相关。利用铝上 P、Zn、Cu、Se、F、As、Cd 和 Ni 通量的比率与深度剖面，我们重建了莫愁湖流域的历史海鸟种群。过去期间 C. 2800年来，海鸟种群在没有人类活动的情况下经历了大幅变化，并确定了四个低谷。与古气候记录和冰川进退历史相比，海鸟数量的明显下降似乎与气候恶化有关。
An 85-cm long sediment sequence from Mochou Lake on Mirror Peninsula in the Larsemann Hills, East Antarctica, was investigated for elemental geochemistry, biogeochemistry and strontium (Sr) isotopic composition in the acid-insoluble and acid-soluble fractions. The biogeochemical data showed that the freshwater lacustrine sediment originated after 2750 BP. The element Zn, Cu, F, P and Se fluxes displayed almost the same vertical distribution patterns, and their ratios over loss on ignition had strong positive correlations with each other, indicating a common source, probably from seabird droppings. The Sr isotopic compositions provided further evidence of the influence of seabirds on the freshwater lacustrine sediments. The Sr-87/(86) Sr ratios determined in the acid-soluble fraction were remarkably lower than those of the acid-insoluble fraction; with a bedrock Sr-87/(86) Sr signature, they were close to those of the marine-derived Sr and were negatively correlated with total amino acids. Using the ratio vs. depth profiles of P, Zn, Cu, Se, F, As, Cd and Ni fluxes over Al, we reconstructed the historical seabird population in the catchment area of Mochou Lake. During the past c. 2800 years, the seabird population has experienced substantial changes in the absence of human activity, and four troughs were identified. After comparison with the palaeoclimatic records and glacial advance and retreat history, the pronounced seabird population declines seem to be related to climatic deterioration.