Bacteriohopanepolyol biomarker composition of organic matter exported to the Arctic Ocean by seven of the major Arctic rivers

Martin P. Cooke, Bart E. van Dongen, Helen M. Talbot, Igor Semiletov, Natalia Shakhova, Laodong Guo, Örjan Gustafsson

Research output: Contribution to journalArticlepeer-review

31 Citations (Scopus)

Abstract

Bacteriohopanepolyols (BHPs) are a diverse group of membrane lipids produced by a wide variety of bacteria and can be used as molecular biomarkers for bacterial processes and populations in both modern and ancient environments. A group of BHPs, including adenosylhopane and structurally related compounds, have been identified as being specific to soils, enabling the transport of terrestrial organic matter (terrOM) to the marine realm to be monitored. Estuary surface sediment samples were obtained from the five Great Russian Arctic Rivers (GRARs; Ob, Yenisey, Lena, Indigirka and Kolyma) and river sediments were obtained from two North American Rivers (Yukon and Mackenzie). Analysis of the BHP signatures, using high performance liquid chromatography-tandem mass spectrometry (HPLC-MSn), indicated the presence of 15 different BHPs originating from a variety of different bacteria, as well as a significant presence of terrestrially derived OM. Total BHP abundance and the contribution of the "soil-marker" BHPs to the total BHP pool increased eastwards among the GRAR sediments. This suggests increasing terrestrial OM or increased preservation of OM as a result of shorter periods of permafrost thawing. The North American rivers showed greatly differing BHP levels between the Yukon and Mackenzie rivers, with a greater BHP input and thus a relatively higher soil OM contribution from the Yukon. The Indigirka River basin in the eastern Siberian Arctic appeared to be the epicentre in the pan-Arctic BHP distribution trend, with the highest "soil-marker" BHPs but the lowest tetrafunctionalised BHPs. Aminobacteriohopanepentol, an indicator of aerobic methane oxidation, was observed in all the sediments, with the source being either the marine environment or methane producing terrestrial environments.

Original languageEnglish
Pages (from-to)1151-1159
Number of pages9
JournalOrganic Geochemistry
Volume40
Issue number11
DOIs
Publication statusPublished - Nov 2009
Externally publishedYes

ASJC Scopus subject areas

  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'Bacteriohopanepolyol biomarker composition of organic matter exported to the Arctic Ocean by seven of the major Arctic rivers'. Together they form a unique fingerprint.

Cite this