Publication
Title
Bacteriohopanepolyol distribution in Yenisei River and Kara Sea suspended particulate matter and sediments traces terrigenous organic matter input
Author
Abstract
Bacteriohopanepolyols (BHPs) are ubiquitous bacterial membrane lipids, encountered in soils, river and marine suspended particulate matter (SPM) and sediments. Their abundance and distribution provides a direct means to identify bacterial inputs and can be used to trace soil-derived bacterial organic matter (OM) and in some cases the presence of bacterial groups and their activities in aquatic systems. We have studied the BHP distribution in the SPM of a major Siberian River (Yenisei River) that crosses a large latitudinal gradient, draining a large part of Mongolia and Siberian Russia. The Yenisei River is the main river to flow into the Kara Sea, a shelf sea of the Arctic Ocean. We show that the BHP distribution and concentration of SPM and surface sediments of the Yenisei Outflow in the Kara Sea allow to trace soil-marker BHPs and evaluate the performance of the R-soil' index, a proxy developed to trace bacterial soil-derived OM. Soil-marker BHPs are present in the Yenisei River, and their concentration decreases from the Yenisei River Outflow into the offshore marine sediments. The R-soil' correlates well with an independent proxy for bacterial OM, the BIT-index (r(2) = 0.82) and has a moderate correlation with the delta C-13(org) values, a bulk OM proxy for terrigenous input (r(2) = 0.44). Consequently, the R-soil' index performs well in the Kara Sea, strengthening its application for tracing bacterial OM in the Arctic Ocean, both in modern and downcore sediments. Furthermore, a suite of BHPs that are characteristic for methanotrophic bacteria, i.e. 35-aminobacteriohopane-30,31,32,33,34-pentol (aminopentol) and 35-aminobacteriohopane-31,32,33,34-tetrol (aminotetrol), is encountered in the Yenisei Outflow sediments. These components are partly sourced from terrigenous sources, but are likely also produced in-situ in the marine sediments. The distribution of the pentafunctionalized cyclitol ether BHP in the marine systems is noteworthy, and indicates that it can possibly be applied as a marker for cyanobacterial biomass in marine sediments. (c) 2015 Elsevier Ltd. All rights reserved.
Language
English
Source (journal)
Geochimica et cosmochimica acta. - Oxford, 1950, currens
Publication
Oxford : 2016
ISSN
0016-7037 [print]
1872-9533 [online]
DOI
10.1016/J.GCA.2015.11.008
Volume/pages
174 (2016) , p. 85-101
ISI
000368819800007
Full text (Publisher's DOI)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Project info
PACEMAKER: Past Continental Climate Change: Temperatures from marine and lacustrine archives
Publication type
Subject
External links
Web of Science
Record
Identifier
Creation 10.10.2017
Last edited 09.10.2023
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