Exceptionally high respiration rates in the reactive surface layer of sediments underlying oxygen-deficient bottom waters
van de Velde, S.J.; Hylén, A.; Eriksson, M.; James, R.K.; Kononets, M.Y.; Robertson, E.K.; Hall, P.O.J. (2023). Exceptionally high respiration rates in the reactive surface layer of sediments underlying oxygen-deficient bottom waters. Proc. - Royal Soc., Math. Phys. Eng. Sci. 479(2275): 20230189. https://dx.doi.org/10.1098/rspa.2023.0189
In: Proceedings of the Royal Society. Mathematical, Physical and Engineering Sciences. Royal Society: London (6 Carlton House Terrace, London SW1Y 5AG). ISSN 1364-5021; e-ISSN 1471-2946, more
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| Authors | | Top |
- van de Velde, S.J., more
- Hylén, A., more
- Eriksson, M.
- James, R.K., more
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- Kononets, M.Y., more
- Robertson, E.K.
- Hall, P.O.J.
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| Abstract |
Organic carbon (OC) burial efficiency, which relates the OC burial rate to respiration in the seafloor, is a critical parameter in the reconstruction of past marine primary productivities. The current accepted theory is that sediments underlying oxygen-deficient (anoxic) bottom waters have low respiration rates and high OC burial efficiencies. By combining novel in situ measurements in anoxic basins with reaction-transport modelling, we demonstrate that sediments underlying anoxic bottom waters have much higher respiration rates than commonly assumed. A major proportion of the carbon respiration is concentrated in the top millimeter—the so-called ‘reactive surface layer’—which is likely a feature in approximately 15% of the coastal seafloor. When re-evaluating previously published data in light of our results, we conclude that the impact of bottom-water anoxia on OC burial efficiencies in marine sediments is small. Consequently, reconstructions of past marine primary productivity in a predominantly anoxic ocean based on OC burial rates might be underestimated by up to an order of magnitude. |
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