Contrasting regimes for organic matter degradation in the East Siberian Sea and the Laptev Sea assessed through microbial incubations and molecular markersShow others and affiliations
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2015 (English)In: Marine Chemistry, ISSN 0304-4203, E-ISSN 1872-7581, Vol. 170Article in journal (Refereed) Published
Abstract [en]
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) (15 mu mol CO2 g OC-1 day(-1)) compared to the Laptev Sea Buor-Khaya Bay (LS-BKB) (2.4 mu mol CO2 g OC-1 day(-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 (r(2) = 0.93-0.96, p < 0.01, linear regression) and two wax lipid-based degradation proxies (r(2) = 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. (C) 2014 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
2015. Vol. 170
Keywords [en]
Organic matter lability Reactivity Decomposition Remineralization Terrestrial organic carbon Incubations Arctic Ocean Coastal shelf Continental margin Permafrost Wax lipids Lignin CuO oxidation Organic geochemistry Sediment arctic-ocean sediments buor-khaya bay marine-sediments terrestrial biomarkers washington margin surface sediments lipid biomarkers early diagenesis carbon isotopes shelf waters Chemistry Oceanography
National Category
Natural Sciences
Research subject
SWEDARCTIC 2008, ISSS-08
Identifiers
URN: urn:nbn:se:polar:diva-1907DOI: 10.1016/j.marchem.2014.12.005OAI: oai:DiVA.org:polar-1907DiVA, id: diva2:810414
Note
ISI Document Delivery No.: CD2WE Times Cited: 0 Cited Reference Count: 113 Karlsson, E. S. Bruchert, V. Tesi, T. Charkin, A. Dudarev, O. Semiletov, I. Gustafsson, O. Knut and Alice Wallenberg Foundation [2011.0027]; Nordic Council of Ministries Cryosphere-Climate-Carbon Initiative (project Defrost) [23001]; Headquarters of the Far Eastern Branch of the Russian Academy of Sciences, Government of the Russian Federation [2013-220-04-157]; Swedish Research Council [621-2004-4039, 621-2007-4631, 621-2013-5297]; US National Oceanic and Atmospheric Administration (Siberian Shelf Study); Russian Foundation of Basic Research [08-05-13572, 13-05-12028, 13-05-12041]; Swedish Polar Research Secretariat; US National Science Foundation [OPP ARC 0909546]; President Grants for Government Support of Young Scientists of the Russian Federation [2575.2014.5]; EU [PIEF-GA-2011-300259] We thank the crew and personnel of the International Siberian Shelf Study 2008 (ISSS-08) and the crew of the sub-expedition on board TB0012. The ISSS and SWERUS C3 programs are supported by the Knut and Alice Wallenberg Foundation (contract no. 2011.0027), the Nordic Council of Ministries Cryosphere-Climate-Carbon Initiative (project Defrost, contract no. 23001), Headquarters of the Far Eastern Branch of the Russian Academy of Sciences, Government of the Russian Federation (grant #2013-220-04-157), the Swedish Research Council (VR Contract No. 621-2004-4039 and 621-2007-4631 and 621-2013-5297), the US National Oceanic and Atmospheric Administration (Siberian Shelf Study), the Russian Foundation of Basic Research (08-05-13572, 13-05-12028 and 13-05-12041), the Swedish Polar Research Secretariat, the US National Science Foundation (OPP ARC 0909546), and the President Grants for Government Support of Young Scientists of the Russian Federation (MK-2575.2014.5). T. Tesi acknowledges EU financial support as Marie Curie fellow (contract no. PIEF-GA-2011-300259). 0 Elsevier science bv Amsterdam Chemistry, Multidisciplinary; Oceanography
2015-05-072015-05-062017-12-04Bibliographically approved