Paleoecological implications of the nitrogen isotope signatures in the sediments amended by Antarctic seal excrements  

作　　者：LIUXiaodong SUNLiguang YINXuebin ZHURenbin 

机构地区：[1]InstituteofPolarEnvironment,UniversityofScienceandTechnologyofChina,Hefei230026,China

出　　处：《Progress in Natural Science:Materials International》2004年第9期786-792,共7页自然科学进展·国际材料（英文版）

基　　金：theNationalNaturalScienceFoundationofChina(GrantNos.40076032and40231002)

摘　　要：The nitrogen isotope signatures in the sediments amended by seal excrements, from Fildes Peninsula of King George Islands, Antarctica, were examined for their paleoecological application potential. The contents of total organic carbon (TOC) and total nitrogen (TN) and the atomic C/N ratios in the sediments show that the organic carbon and nitrogen are predominantly of marine origin and derived from seal excrements. The remarkably high δ 15 N values in the sediments may be related to at least two important factors of trophic enrichment and NH 3 volatilization, which requires further studies. The large variations in the seal hair abundances and the determined δ 15 N values in the sediments signify similar changes of the historical seal populations around the study site. A significant negative correlation between the δ 15 N values and seal hair abundance was observed, and this suggests that the δ 15 N values, like the number of seal hairs, can be used as a paleoecological proxy for the historical seal populations. The time integrated δ 15 N signatures in the sediments with predominantly animal derived nitrogen source thus provide a new tool for estimating historical populations of seals and penguins and interpreting the underlying paleoecological processes.The nitrogen isotope signatures in the sediments amended by seal excrements, from Fildes Peninsula of King George Islands, Antarctica, were examined for their paleoecological application potential. The contents of total organic carbon (TOC) and total nitrogen (TN) and the atomic C/N ratios in the sediments show that the organic carbon and nitrogen are predominantly of marine origin and derived from seal excrements. The remarkably high δ 15 N values in the sediments may be related to at least two important factors of trophic enrichment and NH 3 volatilization, which requires further studies. The large variations in the seal hair abundances and the determined δ 15 N values in the sediments signify similar changes of the historical seal populations around the study site. A significant negative correlation between the δ 15 N values and seal hair abundance was observed, and this suggests that the δ 15 N values, like the number of seal hairs, can be used as a paleoecological proxy for the historical seal populations. The time integrated δ 15 N signatures in the sediments with predominantly animal derived nitrogen source thus provide a new tool for estimating historical populations of seals and penguins and interpreting the underlying paleoecological processes.

关 键 词：nitrogen isotope PALEOECOLOGY seal excrement sediment sequence Antarctica. 

分 类 号：P728.2[天文地球—海洋科学] P736.21