BIOMARKERS IN SEDIMENTS IN THE ARCTIC AREAS AND ECOLOGICAL ENVIRONMENTAL RESPONSE

Core samples C8 and B_2-9 from the seafloor of the Arctic were dated with ²¹⁰Pb to obtain a consecutive sequence of oceanic sedimentary environments at the interval of a decade during 1880-1999 and 1889-1999. A variety of biomarkers were detected, including n-alkane, isoprenoid, fatty acid, sterol, etc.According to the characteristics of their molecular indices (∑nC₂₂+/nC₂₁^-、TAB_HC,CPI,CPI_A,∑C_20:0-/nC_20:0⁺, C_18:2/C_18:0) and in consideration of the variation of sterols content (C₂₇, C₂₈, and C₂₉ sterols),the 100-year variation history of subarctic sea paleoenvironment was reestablished. Composition of organic matter indicates that substance is mainly contributed by the terrigenous origin and marine silicate organisms. The results also suggest that the record of biomarkers from the surface sediments (3~0 cm)in the Bering Sea represents a period from 1980s to the late 1990s. The strong signal of the Arctic warming is preserved in the sediments. The fact that Arctic greenhouse effect was multiplied has further proved the response of marine biological process in the polar region to the climate change.