Abstract
Compositional studies of organic matter on the East Siberian Arctic Shelf (ESAS) suggest that different terrestrial carbon pools have different propensities for transport and/or degradation. The current study combined laboratory-based microbial degradation experiments with earlier published degradation-diagnostic composition of several classes of terrestrial biomarkers on the same sediments to investigate differences and driving forces of terrestrial organic matter (TerrOM) degradation in two biogeochemically-contrasting regimes of the ESAS.The incubation-based anaerobic degradation rates were consistently higher (by average factor of 6) in the East Siberian Sea Kolyma Paleoriver Channel (ESS-KPC) (15μmolCO2gOC-1day-1) compared to the Laptev Sea Buor-Khaya Bay (LS-BKB) (2.4μmolCO2gOC-1day-1).The reported molecular markers show similarities between the terrestrial carbon pools in the two systems, but impose contrasting degradation regimes in combination with the incubation results. For the LS-BKB, there was a strong relationship between the degradation rates and the three lignin phenol-based degradation proxies (r2=0.93-0.96, p<0.01, linear regression) and two wax lipid-based degradation proxies (r2=0.71 and 0.66, p<0.05, linear regression). In contrast, for the ESS-KPC system, there was no relationship between incubation-based degradation rates and molecular marker-based degradation status of TerrOM. A principal component analysis indicated that short-chain fatty acids and dicarboxylic acids from CuO oxidation are mainly of terrestrial origin in the LS-BKB, but mainly of marine origin in the ESS-KPC. Hence, the microbial degradation in the western (LS-BKB) system appears to be fueled by TerrOM whereas the eastern (ESS-KPC) system degradation appears to be driven by MarOM. By combining molecular fingerprinting of TerrOM degradation state with laboratory-based degradation studies on the same ESAS sediments, a picture evolves of two distinctly different modes of TerrOM degradation in different parts of the ESAS system.
| Original language | English |
|---|---|
| Pages (from-to) | 11-22 |
| Number of pages | 12 |
| Journal | Marine Chemistry |
| Volume | 170 |
| DOIs | |
| Publication status | Published - 1 Mar 2015 |
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Keywords
- Arctic Ocean
- Coastal shelf
- Continental margin
- CuO oxidation
- Decomposition
- Incubations
- Lignin
- Organic geochemistry
- Organic matter lability
- Permafrost
- Reactivity
- Remineralization
- Sediment
- Terrestrial organic carbon
- Wax lipids
ASJC Scopus subject areas
- Oceanography
- Chemistry(all)
- Environmental Chemistry
- Water Science and Technology
Cite this
Contrasting regimes for organic matter degradation in the East Siberian Sea and the Laptev Sea assessed through microbial incubations and molecular markers. / Karlsson, E. S.; Brüchert, V.; Tesi, T.; Charkin, A.; Dudarev, Oleg Victorovich; Semiletov, Igor Petrovich; Gustafsson, O.
In: Marine Chemistry, Vol. 170, 01.03.2015, p. 11-22.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Contrasting regimes for organic matter degradation in the East Siberian Sea and the Laptev Sea assessed through microbial incubations and molecular markers
AU - Karlsson, E. S.
AU - Brüchert, V.
AU - Tesi, T.
AU - Charkin, A.
AU - Dudarev, Oleg Victorovich
AU - Semiletov, Igor Petrovich
AU - Gustafsson, O.
PY - 2015/3/1
Y1 - 2015/3/1
N2 - Compositional studies of organic matter on the East Siberian Arctic Shelf (ESAS) suggest that different terrestrial carbon pools have different propensities for transport and/or degradation. The current study combined laboratory-based microbial degradation experiments with earlier published degradation-diagnostic composition of several classes of terrestrial biomarkers on the same sediments to investigate differences and driving forces of terrestrial organic matter (TerrOM) degradation in two biogeochemically-contrasting regimes of the ESAS.The incubation-based anaerobic degradation rates were consistently higher (by average factor of 6) in the East Siberian Sea Kolyma Paleoriver Channel (ESS-KPC) (15μmolCO2gOC-1day-1) compared to the Laptev Sea Buor-Khaya Bay (LS-BKB) (2.4μmolCO2gOC-1day-1).The reported molecular markers show similarities between the terrestrial carbon pools in the two systems, but impose contrasting degradation regimes in combination with the incubation results. For the LS-BKB, there was a strong relationship between the degradation rates and the three lignin phenol-based degradation proxies (r2=0.93-0.96, p<0.01, linear regression) and two wax lipid-based degradation proxies (r2=0.71 and 0.66, p<0.05, linear regression). In contrast, for the ESS-KPC system, there was no relationship between incubation-based degradation rates and molecular marker-based degradation status of TerrOM. A principal component analysis indicated that short-chain fatty acids and dicarboxylic acids from CuO oxidation are mainly of terrestrial origin in the LS-BKB, but mainly of marine origin in the ESS-KPC. Hence, the microbial degradation in the western (LS-BKB) system appears to be fueled by TerrOM whereas the eastern (ESS-KPC) system degradation appears to be driven by MarOM. By combining molecular fingerprinting of TerrOM degradation state with laboratory-based degradation studies on the same ESAS sediments, a picture evolves of two distinctly different modes of TerrOM degradation in different parts of the ESAS system.
AB - Compositional studies of organic matter on the East Siberian Arctic Shelf (ESAS) suggest that different terrestrial carbon pools have different propensities for transport and/or degradation. The current study combined laboratory-based microbial degradation experiments with earlier published degradation-diagnostic composition of several classes of terrestrial biomarkers on the same sediments to investigate differences and driving forces of terrestrial organic matter (TerrOM) degradation in two biogeochemically-contrasting regimes of the ESAS.The incubation-based anaerobic degradation rates were consistently higher (by average factor of 6) in the East Siberian Sea Kolyma Paleoriver Channel (ESS-KPC) (15μmolCO2gOC-1day-1) compared to the Laptev Sea Buor-Khaya Bay (LS-BKB) (2.4μmolCO2gOC-1day-1).The reported molecular markers show similarities between the terrestrial carbon pools in the two systems, but impose contrasting degradation regimes in combination with the incubation results. For the LS-BKB, there was a strong relationship between the degradation rates and the three lignin phenol-based degradation proxies (r2=0.93-0.96, p<0.01, linear regression) and two wax lipid-based degradation proxies (r2=0.71 and 0.66, p<0.05, linear regression). In contrast, for the ESS-KPC system, there was no relationship between incubation-based degradation rates and molecular marker-based degradation status of TerrOM. A principal component analysis indicated that short-chain fatty acids and dicarboxylic acids from CuO oxidation are mainly of terrestrial origin in the LS-BKB, but mainly of marine origin in the ESS-KPC. Hence, the microbial degradation in the western (LS-BKB) system appears to be fueled by TerrOM whereas the eastern (ESS-KPC) system degradation appears to be driven by MarOM. By combining molecular fingerprinting of TerrOM degradation state with laboratory-based degradation studies on the same ESAS sediments, a picture evolves of two distinctly different modes of TerrOM degradation in different parts of the ESAS system.
KW - Arctic Ocean
KW - Coastal shelf
KW - Continental margin
KW - CuO oxidation
KW - Decomposition
KW - Incubations
KW - Lignin
KW - Organic geochemistry
KW - Organic matter lability
KW - Permafrost
KW - Reactivity
KW - Remineralization
KW - Sediment
KW - Terrestrial organic carbon
KW - Wax lipids
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UR - http://www.scopus.com/inward/citedby.url?scp=84921745787&partnerID=8YFLogxK
U2 - 10.1016/j.marchem.2014.12.005
DO - 10.1016/j.marchem.2014.12.005
M3 - Article
VL - 170
SP - 11
EP - 22
JO - Marine Chemistry
JF - Marine Chemistry
SN - 0304-4203
ER -