Variability of Nonionellina labradorica Dawson in Surface Sediments from Kongsfjorden,West Spitsbergen  

作　　者：Suhas SHETYE Rahul MOHAN Sunil Kumar SHUKLA Sudhakar MARUTHADU Rasik RAVINDRA 

机构地区：[1]National Centre for Antarctic and Ocean Research Goa,India [2]Ministry of Earth Sciences New Delhi,India

出　　处：《Acta Geologica Sinica(English Edition)》2011年第3期549-558,共10页地质学报（英文版）

摘　　要：Kongsfjorden is a fjord in Spitsbergen（Svalbard archipelago）that lies adjacent to both Arctic and Atlantic water masses and is therefore a suitable site to understand the effects of climate change on ecosystems.To decipher the effect of the lateral advection of transformed Atlantic water （TAW）within the fjord,spatial variations of foraminiferal tests,their test size variations and stable isotopic composition（δ^（13）C andδ^（18）O）in the surface sediments were studied.Total organic carbon and textural analyses were also carried out.The dominant benthic foraminifera included Nonionellina labradorica,Elphidium excavatum,Cassidulina reniforme,Quinqueloculina stalkeri and Islandiella islandica.Nonionellina labradorica was the predominant species in the outer fjord,whereas Elphidium excavatum and Cassidulina reniforme were dominant in the inner fjord.Total organic carbon and the test size of Nonionellina labradorica within the fjord were highly correlated（r=0.97）and both showed a decreasing trend towards the inner fjord.Based on the distribution and abundance of Nonionellina labradorica as well as temperature profiles,we suggest that there was little or no major change in the lateral advection of TAW within the fjord in the immediate past.Kongsfjorden is a fjord in Spitsbergen（Svalbard archipelago）that lies adjacent to both Arctic and Atlantic water masses and is therefore a suitable site to understand the effects of climate change on ecosystems.To decipher the effect of the lateral advection of transformed Atlantic water （TAW）within the fjord,spatial variations of foraminiferal tests,their test size variations and stable isotopic composition（δ^（13）C andδ^（18）O）in the surface sediments were studied.Total organic carbon and textural analyses were also carried out.The dominant benthic foraminifera included Nonionellina labradorica,Elphidium excavatum,Cassidulina reniforme,Quinqueloculina stalkeri and Islandiella islandica.Nonionellina labradorica was the predominant species in the outer fjord,whereas Elphidium excavatum and Cassidulina reniforme were dominant in the inner fjord.Total organic carbon and the test size of Nonionellina labradorica within the fjord were highly correlated（r=0.97）and both showed a decreasing trend towards the inner fjord.Based on the distribution and abundance of Nonionellina labradorica as well as temperature profiles,we suggest that there was little or no major change in the lateral advection of TAW within the fjord in the immediate past.

关 键 词：West Spitsbergen Current KONGSFJORDEN Nonionellina labradorica grain size organic carbon stable isotopes temperature 

分 类 号：P736.21[天文地球—海洋地质]