Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis
Molecular lipid biomarkers (hydrocarbons, alcohols, sterols and fatty acids) and compound-specific isotope analysis of suspended particulate organic matter (SPM) and surface sediments of the Mackenzie Shelf and slope (southeast Beaufort Sea, Arctic Ocean) were studied in summer 2009. The concentrati...
Published in: | Biogeosciences |
---|---|
Main Authors: | , , , , |
Format: | Text |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/bg-10-2061-2013 https://www.biogeosciences.net/10/2061/2013/ |
id |
ftcopernicus:oai:publications.copernicus.org:bg16112 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:bg16112 2023-05-15T13:22:55+02:00 Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis Tolosa, I. Fiorini, S. Gasser, B. Martín, J. Miquel, J. C. 2018-09-27 application/pdf https://doi.org/10.5194/bg-10-2061-2013 https://www.biogeosciences.net/10/2061/2013/ eng eng doi:10.5194/bg-10-2061-2013 https://www.biogeosciences.net/10/2061/2013/ eISSN: 1726-4189 Text 2018 ftcopernicus https://doi.org/10.5194/bg-10-2061-2013 2019-12-24T09:55:27Z Molecular lipid biomarkers (hydrocarbons, alcohols, sterols and fatty acids) and compound-specific isotope analysis of suspended particulate organic matter (SPM) and surface sediments of the Mackenzie Shelf and slope (southeast Beaufort Sea, Arctic Ocean) were studied in summer 2009. The concentrations of the molecular lipid markers, characteristic of known organic matter sources, were grouped and used as proxies to evaluate the relative importance of fresh algal, detrital algal, fossil, C 3 terrestrial plants, bacterial and zooplankton material in the organic matter (OM) of this area. Fossil and detrital algal contributions were the major fractions of the freshwater SPM from the Mackenzie River with ~34% each of the total molecular biomarkers. Fresh algal, C 3 terrestrial, bacterial and zooplanktonic components represented much lower percentages, 17, 10, 4 and <1%, respectively. In marine SPM from the Mackenzie slope, the major contributions were fresh and detrital algal components (>80%), with a minor contribution of fossil and C 3 terrestrial biomarkers. Characterization of the sediments revealed a major sink of refractory algal material mixed with some fresh algal material, fossil hydrocarbons and a small input of C 3 terrestrial sources. In particular, the sediments from the shelf and at the mouth of the Amundsen Gulf presented the highest contribution of detrital algal material (60–75%), whereas those from the slope contained the highest proportion of fossil (40%) and C 3 terrestrial plant material (10%). Overall, considering that the detrital algal material is marine derived, autochthonous sources contributed more than allochthonous sources to the OM lipid pool. Using the ratio of an allochthonous biomarker (normalized to total organic carbon, TOC) found in the sediments to those measured at the river mouth water, we estimated that the fraction of terrestrial material preserved in the sediments accounted for 30–40% of the total carbon in the inner shelf sediments, 17% in the outer shelf and Amundsen Gulf and up to 25% in the slope sediments. These estimates are low compared to other studies conducted 5–20 yr earlier, and they support the increase in primary production during the last decade mainly because of the increase in the number of ice-free days and due to the strength and persistence of winds favouring upwelling. Text Amundsen Gulf Arctic Arctic Ocean Beaufort Sea Mackenzie river Mackenzie Shelf Zooplankton Copernicus Publications: E-Journals Arctic Arctic Ocean Mackenzie River Biogeosciences 10 3 2061 2087 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Molecular lipid biomarkers (hydrocarbons, alcohols, sterols and fatty acids) and compound-specific isotope analysis of suspended particulate organic matter (SPM) and surface sediments of the Mackenzie Shelf and slope (southeast Beaufort Sea, Arctic Ocean) were studied in summer 2009. The concentrations of the molecular lipid markers, characteristic of known organic matter sources, were grouped and used as proxies to evaluate the relative importance of fresh algal, detrital algal, fossil, C 3 terrestrial plants, bacterial and zooplankton material in the organic matter (OM) of this area. Fossil and detrital algal contributions were the major fractions of the freshwater SPM from the Mackenzie River with ~34% each of the total molecular biomarkers. Fresh algal, C 3 terrestrial, bacterial and zooplanktonic components represented much lower percentages, 17, 10, 4 and <1%, respectively. In marine SPM from the Mackenzie slope, the major contributions were fresh and detrital algal components (>80%), with a minor contribution of fossil and C 3 terrestrial biomarkers. Characterization of the sediments revealed a major sink of refractory algal material mixed with some fresh algal material, fossil hydrocarbons and a small input of C 3 terrestrial sources. In particular, the sediments from the shelf and at the mouth of the Amundsen Gulf presented the highest contribution of detrital algal material (60–75%), whereas those from the slope contained the highest proportion of fossil (40%) and C 3 terrestrial plant material (10%). Overall, considering that the detrital algal material is marine derived, autochthonous sources contributed more than allochthonous sources to the OM lipid pool. Using the ratio of an allochthonous biomarker (normalized to total organic carbon, TOC) found in the sediments to those measured at the river mouth water, we estimated that the fraction of terrestrial material preserved in the sediments accounted for 30–40% of the total carbon in the inner shelf sediments, 17% in the outer shelf and Amundsen Gulf and up to 25% in the slope sediments. These estimates are low compared to other studies conducted 5–20 yr earlier, and they support the increase in primary production during the last decade mainly because of the increase in the number of ice-free days and due to the strength and persistence of winds favouring upwelling. |
format |
Text |
author |
Tolosa, I. Fiorini, S. Gasser, B. Martín, J. Miquel, J. C. |
spellingShingle |
Tolosa, I. Fiorini, S. Gasser, B. Martín, J. Miquel, J. C. Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis |
author_facet |
Tolosa, I. Fiorini, S. Gasser, B. Martín, J. Miquel, J. C. |
author_sort |
Tolosa, I. |
title |
Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis |
title_short |
Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis |
title_full |
Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis |
title_fullStr |
Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis |
title_full_unstemmed |
Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis |
title_sort |
carbon sources in suspended particles and surface sediments from the beaufort sea revealed by molecular lipid biomarkers and compound-specific isotope analysis |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-10-2061-2013 https://www.biogeosciences.net/10/2061/2013/ |
geographic |
Arctic Arctic Ocean Mackenzie River |
geographic_facet |
Arctic Arctic Ocean Mackenzie River |
genre |
Amundsen Gulf Arctic Arctic Ocean Beaufort Sea Mackenzie river Mackenzie Shelf Zooplankton |
genre_facet |
Amundsen Gulf Arctic Arctic Ocean Beaufort Sea Mackenzie river Mackenzie Shelf Zooplankton |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-10-2061-2013 https://www.biogeosciences.net/10/2061/2013/ |
op_doi |
https://doi.org/10.5194/bg-10-2061-2013 |
container_title |
Biogeosciences |
container_volume |
10 |
container_issue |
3 |
container_start_page |
2061 |
op_container_end_page |
2087 |
_version_ |
1766367867151843328 |