极地研究

极地研究 ›› 2005, Vol. 16 ›› Issue (2-English): 121-134.

• 目次 • 上一篇    

Elemental and Isotopic Signatures in the Sediments Influenced by Seal Excrement on Antarctic Fildes Peninsula and Their Potential Paleoecological Applications

 Liu Xiaodong1, Sun Liguang1, Yin Xuebin1, Xie Zhouqing1, Zhu Renbin1 and Wang Yuhong1,2   

  1. 1 Institute of Polar Environment, University of Science and Technology of China, Hefei 230026, China;
    2 National Institute of Health, Marylan 20892, USA
  • 出版日期:1955-06-30 发布日期:1955-06-30
  • 通讯作者: Liu Xiaodong

Elemental and Isotopic Signatures in the Sediments Influenced by Seal Excrement on Antarctic Fildes Peninsula and Their Potential Paleoecological Applications

 Liu Xiaodong1, Sun Liguang1, Yin Xuebin1, Xie Zhouqing1, Zhu Renbin1 and Wang Yuhong1,2   

  1. 1 Institute of Polar Environment, University of Science and Technology of China, Hefei 230026, China;
    2 National Institute of Health, Marylan 20892, USA
  • Online:1955-06-30 Published:1955-06-30
  • Contact: Liu Xiaodong

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摘要：

The elemental and isotopic signatures in the sediments influenced by seal excrement on Antarctic Fildes Peninsula are examined for their potential palaeoecological applications. The seal hair abundance in sediments exhibits remarkable fluctuation versus depth, indicating similar changes in historical populations of the seals visiting the marine terrace. The combination of δ13C, total organic carbon concentration (TOC), total nitrogen concentration (TN) and atomic C/N ratio shows that the organic matters in sediments with numerous seal hairs have a marine origin and are predominantly derived from seal excrements.The large δ15N values in sediments are attributed to trophic enrichment and NH3 volatilization processes. The large variations in the δ15N values and the negative cor- relation between the δ15N values and the seal hair abundances seem to be the re- suits of changes in the paleoclimates and the volatilization rates of the ammonia produced in the seal excrements.The 87Sr/86Sr ratios in the acid-soluble fraction of sediments are interpreted as a mixture of the ones from the seal excrements (30%-50%) and the chemically weathered local bedrocks (70%-50%). The calculated proportion of seal-derived Sr based on the 87Sr/86Sr ratios has a signifi- cant correlation with seal hair abundances in sediments. These results suggest that δ15N values and the 87Sr/86Sr ratios in the acid-soluble fraction of sediments were influenced by seal excrements, similar to seal hair numbers, and thus can potentially be used to estimate the historical seal population in the Antarctic region.

关键词: Antarctica, sediment, seal excrement, isotope ratios, palaeoecology

Abstract:

The elemental and isotopic signatures in the sediments influenced by seal excrement on Antarctic Fildes Peninsula are examined for their potential palaeoecological applications. The seal hair abundance in sediments exhibits remarkable fluctuation versus depth, indicating similar changes in historical populations of the seals visiting the marine terrace. The combination of δ13C, total organic carbon concentration (TOC), total nitrogen concentration (TN) and atomic C/N ratio shows that the organic matters in sediments with numerous seal hairs have a marine origin and are predominantly derived from seal excrements.The large δ15N values in sediments are attributed to trophic enrichment and NH3 volatilization processes. The large variations in the δ15N values and the negative cor- relation between the δ15N values and the seal hair abundances seem to be the re- suits of changes in the paleoclimates and the volatilization rates of the ammonia produced in the seal excrements.The 87Sr/86Sr ratios in the acid-soluble fraction of sediments are interpreted as a mixture of the ones from the seal excrements (30%-50%) and the chemically weathered local bedrocks (70%-50%). The calculated proportion of seal-derived Sr based on the 87Sr/86Sr ratios has a signifi- cant correlation with seal hair abundances in sediments. These results suggest that δ15N values and the 87Sr/86Sr ratios in the acid-soluble fraction of sediments were influenced by seal excrements, similar to seal hair numbers, and thus can potentially be used to estimate the historical seal population in the Antarctic region.

Key words: Antarctica, sediment, seal excrement, isotope ratios, palaeoecology