Fate of terrigenous organic matter across the Laptev Sea from the mouth of the Lena River to the deep sea of the Arctic interior

Lisa Bröder, Tommaso Tesi, Joan A. Salvadó, Igor P. Semiletov, Oleg V. Dudarev, Orjan Gustafsson

Research output: Chapter in Book / Report / Conference proceedingChapterAcademicpeer-review

Abstract

Ongoing global warming in high latitudes may cause an increasing supply of permafrost-derived organic carbon through both river discharge and coastal erosion to the Arctic shelves. Mobilized permafrost carbon can be either buried in sediments, transported to the deep sea or degraded to CO2 and outgassed, potentially constituting a positive feedback to climate change. This study aims to assess the fate of terrigenous organic carbon (TerrOC) in the Arctic marine environment by exploring how it changes in concentration, composition and degradation status across the wide Laptev Sea shelf. We analyzed a suite of terrestrial biomarkers as well as source-diagnostic bulk carbon isotopes (δ13C, Δ14C) in surface sediments from a Laptev Sea transect spanning more than 800 km from the Lena River mouth (<10 m water depth) across the shelf to the slope and rise (2000–3000 m water depth). These data provide a broad view on different TerrOC pools and their behavior during cross-shelf transport. The concentrations of lignin phenols, cutin acids and high-molecular-weight (HMW) wax lipids (tracers of vascular plants) decrease by 89–99 % along the transect. Molecular-based degradation proxies for TerrOC (e.g., the carbon preference index of HMW lipids, the HMW acids ∕ alkanes ratio and the acid ∕ aldehyde ratio of lignin phenols) display a trend to more degraded TerrOC with increasing distance from the coast. We infer that the degree of degradation of permafrost-derived TerrOC is a function of the time spent under oxic conditions during protracted cross-shelf transport. Future work should therefore seek to constrain cross-shelf transport times in order to compute a TerrOC degradation rate and thereby help to quantify potential carbon–climate feedbacks.
Original languageEnglish
Title of host publicationBiogeosciences
PublisherCopernicus GmbH
Pages5003-5019
Number of pages17
ISBN (Print)1810-6285
DOIs
Publication statusPublished - 9 Sep 2016

Publication series

NameBiogeosciences
Volume13

Fingerprint

deep sea
organic carbon
organic matter
river
permafrost
degradation
lignin
phenol
acid
water depth
transect
lipid
arctic environment
coastal erosion
shelf sea
carbon
aldehyde
wax
sea
oxic conditions

Cite this

Bröder, L., Tesi, T., Salvadó, J. A., Semiletov, I. P., Dudarev, O. V., & Gustafsson, O. (2016). Fate of terrigenous organic matter across the Laptev Sea from the mouth of the Lena River to the deep sea of the Arctic interior. In Biogeosciences (pp. 5003-5019). (Biogeosciences; Vol. 13). Copernicus GmbH. https://doi.org/10.5194/bg-13-5003-2016
Bröder, Lisa ; Tesi, Tommaso ; Salvadó, Joan A. ; Semiletov, Igor P. ; Dudarev, Oleg V. ; Gustafsson, Orjan. / Fate of terrigenous organic matter across the Laptev Sea from the mouth of the Lena River to the deep sea of the Arctic interior. Biogeosciences. Copernicus GmbH, 2016. pp. 5003-5019 (Biogeosciences).
@inbook{39a628e5c58040bf93babcb46bc47db2,
title = "Fate of terrigenous organic matter across the Laptev Sea from the mouth of the Lena River to the deep sea of the Arctic interior",
abstract = "Ongoing global warming in high latitudes may cause an increasing supply of permafrost-derived organic carbon through both river discharge and coastal erosion to the Arctic shelves. Mobilized permafrost carbon can be either buried in sediments, transported to the deep sea or degraded to CO2 and outgassed, potentially constituting a positive feedback to climate change. This study aims to assess the fate of terrigenous organic carbon (TerrOC) in the Arctic marine environment by exploring how it changes in concentration, composition and degradation status across the wide Laptev Sea shelf. We analyzed a suite of terrestrial biomarkers as well as source-diagnostic bulk carbon isotopes (δ13C, Δ14C) in surface sediments from a Laptev Sea transect spanning more than 800 km from the Lena River mouth (<10 m water depth) across the shelf to the slope and rise (2000–3000 m water depth). These data provide a broad view on different TerrOC pools and their behavior during cross-shelf transport. The concentrations of lignin phenols, cutin acids and high-molecular-weight (HMW) wax lipids (tracers of vascular plants) decrease by 89–99 {\%} along the transect. Molecular-based degradation proxies for TerrOC (e.g., the carbon preference index of HMW lipids, the HMW acids ∕ alkanes ratio and the acid ∕ aldehyde ratio of lignin phenols) display a trend to more degraded TerrOC with increasing distance from the coast. We infer that the degree of degradation of permafrost-derived TerrOC is a function of the time spent under oxic conditions during protracted cross-shelf transport. Future work should therefore seek to constrain cross-shelf transport times in order to compute a TerrOC degradation rate and thereby help to quantify potential carbon–climate feedbacks.",
author = "Lisa Br{\"o}der and Tommaso Tesi and Salvad{\'o}, {Joan A.} and Semiletov, {Igor P.} and Dudarev, {Oleg V.} and Orjan Gustafsson",
year = "2016",
month = "9",
day = "9",
doi = "10.5194/bg-13-5003-2016",
language = "English",
isbn = "1810-6285",
series = "Biogeosciences",
publisher = "Copernicus GmbH",
pages = "5003--5019",
booktitle = "Biogeosciences",

}

Bröder, L, Tesi, T, Salvadó, JA, Semiletov, IP, Dudarev, OV & Gustafsson, O 2016, Fate of terrigenous organic matter across the Laptev Sea from the mouth of the Lena River to the deep sea of the Arctic interior. in Biogeosciences. Biogeosciences, vol. 13, Copernicus GmbH, pp. 5003-5019. https://doi.org/10.5194/bg-13-5003-2016

Fate of terrigenous organic matter across the Laptev Sea from the mouth of the Lena River to the deep sea of the Arctic interior. / Bröder, Lisa; Tesi, Tommaso; Salvadó, Joan A.; Semiletov, Igor P.; Dudarev, Oleg V.; Gustafsson, Orjan.

Biogeosciences. Copernicus GmbH, 2016. p. 5003-5019 (Biogeosciences; Vol. 13).

Research output: Chapter in Book / Report / Conference proceedingChapterAcademicpeer-review

TY - CHAP

T1 - Fate of terrigenous organic matter across the Laptev Sea from the mouth of the Lena River to the deep sea of the Arctic interior

AU - Bröder, Lisa

AU - Tesi, Tommaso

AU - Salvadó, Joan A.

AU - Semiletov, Igor P.

AU - Dudarev, Oleg V.

AU - Gustafsson, Orjan

PY - 2016/9/9

Y1 - 2016/9/9

N2 - Ongoing global warming in high latitudes may cause an increasing supply of permafrost-derived organic carbon through both river discharge and coastal erosion to the Arctic shelves. Mobilized permafrost carbon can be either buried in sediments, transported to the deep sea or degraded to CO2 and outgassed, potentially constituting a positive feedback to climate change. This study aims to assess the fate of terrigenous organic carbon (TerrOC) in the Arctic marine environment by exploring how it changes in concentration, composition and degradation status across the wide Laptev Sea shelf. We analyzed a suite of terrestrial biomarkers as well as source-diagnostic bulk carbon isotopes (δ13C, Δ14C) in surface sediments from a Laptev Sea transect spanning more than 800 km from the Lena River mouth (<10 m water depth) across the shelf to the slope and rise (2000–3000 m water depth). These data provide a broad view on different TerrOC pools and their behavior during cross-shelf transport. The concentrations of lignin phenols, cutin acids and high-molecular-weight (HMW) wax lipids (tracers of vascular plants) decrease by 89–99 % along the transect. Molecular-based degradation proxies for TerrOC (e.g., the carbon preference index of HMW lipids, the HMW acids ∕ alkanes ratio and the acid ∕ aldehyde ratio of lignin phenols) display a trend to more degraded TerrOC with increasing distance from the coast. We infer that the degree of degradation of permafrost-derived TerrOC is a function of the time spent under oxic conditions during protracted cross-shelf transport. Future work should therefore seek to constrain cross-shelf transport times in order to compute a TerrOC degradation rate and thereby help to quantify potential carbon–climate feedbacks.

AB - Ongoing global warming in high latitudes may cause an increasing supply of permafrost-derived organic carbon through both river discharge and coastal erosion to the Arctic shelves. Mobilized permafrost carbon can be either buried in sediments, transported to the deep sea or degraded to CO2 and outgassed, potentially constituting a positive feedback to climate change. This study aims to assess the fate of terrigenous organic carbon (TerrOC) in the Arctic marine environment by exploring how it changes in concentration, composition and degradation status across the wide Laptev Sea shelf. We analyzed a suite of terrestrial biomarkers as well as source-diagnostic bulk carbon isotopes (δ13C, Δ14C) in surface sediments from a Laptev Sea transect spanning more than 800 km from the Lena River mouth (<10 m water depth) across the shelf to the slope and rise (2000–3000 m water depth). These data provide a broad view on different TerrOC pools and their behavior during cross-shelf transport. The concentrations of lignin phenols, cutin acids and high-molecular-weight (HMW) wax lipids (tracers of vascular plants) decrease by 89–99 % along the transect. Molecular-based degradation proxies for TerrOC (e.g., the carbon preference index of HMW lipids, the HMW acids ∕ alkanes ratio and the acid ∕ aldehyde ratio of lignin phenols) display a trend to more degraded TerrOC with increasing distance from the coast. We infer that the degree of degradation of permafrost-derived TerrOC is a function of the time spent under oxic conditions during protracted cross-shelf transport. Future work should therefore seek to constrain cross-shelf transport times in order to compute a TerrOC degradation rate and thereby help to quantify potential carbon–climate feedbacks.

U2 - 10.5194/bg-13-5003-2016

DO - 10.5194/bg-13-5003-2016

M3 - Chapter

SN - 1810-6285

T3 - Biogeosciences

SP - 5003

EP - 5019

BT - Biogeosciences

PB - Copernicus GmbH

ER -

Bröder L, Tesi T, Salvadó JA, Semiletov IP, Dudarev OV, Gustafsson O. Fate of terrigenous organic matter across the Laptev Sea from the mouth of the Lena River to the deep sea of the Arctic interior. In Biogeosciences. Copernicus GmbH. 2016. p. 5003-5019. (Biogeosciences). https://doi.org/10.5194/bg-13-5003-2016