Potential role of priming effect in the open ocean oxygen minimum zones: an outlook

Ragavan, P.; Kumar, Sanjeev

doi:10.1007/s10750-021-04574-1

Cited by 5 publications

(6 citation statements)

References 136 publications

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“…The dataset for the Severn estuary (Table 2; row A) is from Thomas (2014). Rhone delta data (Table 2; rows B and C) are from the DI-CASE project (Rassmann et al, 2016). Data for the northern European margin sites Aarhus Bay, Arkona Basin, and the Skagerrak transect (Table 2; rows D, E, G, H, and I) are part of the Europe-funded project METROL (Aquilina et al, 2010;Dale et al, 2008a, b;Knab et al, 2008; (Henkel and Kulkarni, 2015), the Arabian Sea oxygen minimum zone (OMZ) transect (Table 2; rows J, K, and L) (Bohrmann and cruise participants, 2010a, b, c), Bering Sea (Table 2; row M) (Gersonde, 2009), and Argentine Basin (Table 2; row N) (Henkel et al, 2011) are presented in the PANGAEA database (see above).…”

Section: Observational Datamentioning

confidence: 99%

“…Here, we assume a fixed boundary concentration of OM at the SWI. Concentrations of O 2 are based on measurements in Skagerrak (Canfield et al, 1993) and the Rhone delta (Rassmann et al, 2016) sediments. Similarly, concentrations of NO − 3 are based on measurements in Skagerrak sediments (Canfield et al, 1993).…”

Section: Boundary Conditionsmentioning

confidence: 99%

“…7a; Table 6). Consequently, intense oxygen consumption occurs at the SWI (Rassmann et al, 2016) driven by both aerobic degradation of OM and re-oxidation of reduced species. Sim-ilarly, in the Arabian Sea sediments below the OMZ the high input of fresh phytoplankton debris (Cowie, 2005;Koho et al, 2013;Rixen et al, 2019;Vandewiele et al, 2009) and potentially chemoautotroph biomass (Lengger et al, 2019) associated with intense degradation rates in the uppermost sediment layers (Luff et al, 2000) result in a high relative contribution of aerobic degradation of OM and denitrification to total OM oxidation.…”

Section: Om Reactivity Controls On Sediment-water Interface Fluxes Patternsmentioning

confidence: 99%

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New insights into large-scale trends of apparent organic matter reactivity in marine sediments and patterns of benthic carbon transformation

et al. 2021

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Abstract. Constraining the mechanisms controlling organic matter (OM) reactivity and, thus, degradation, preservation, and burial in marine sediments across spatial and temporal scales is key to understanding carbon cycling in the past, present, and future. However, we still lack a detailed quantitative understanding of what controls OM reactivity in marine sediments and, consequently, a general framework that would allow model parametrization in data-poor areas. To fill this gap, we quantify apparent OM reactivity (i.e. OM degradation rate constants) by extracting reactive continuum model (RCM) parameters (a and v, which define the shape and scale of OM reactivity profiles, respectively) from observed benthic organic carbon and sulfate dynamics across 14 contrasting depositional settings distributed over five distinct benthic provinces. We further complement the newly derived parameter set with a compilation of 37 previously published RCM a and v estimates to explore large-scale trends in OM reactivity. Our analysis shows that the large-scale variability in apparent OM reactivity is largely driven by differences in parameter a (10−3–107) with a high frequency of values in the range 100–104 years. In contrast, and in broad agreement with previous findings, inversely determined v values fall within a narrow range (0.1–0.2). Results also show that the variability in parameter a and, thus, in apparent OM reactivity is a function of the whole depositional environment, rather than traditionally proposed, single environmental controls (e.g. water depth, sedimentation rate, OM fluxes). Thus, we caution against the simplifying use of a single environmental control for predicting apparent OM reactivity beyond a specific local environmental context (i.e. well-defined geographic scale). Additionally, model results indicate that, while OM fluxes exert a dominant control on depth-integrated OM degradation rates across most depositional environments, apparent OM reactivity becomes a dominant control in depositional environments that receive exceptionally reactive OM. Furthermore, model results show that apparent OM reactivity exerts a key control on the relative significance of OM degradation pathways, the redox zonation of the sediment, and rates of anaerobic oxidation of methane. In summary, our large-scale assessment (i) further supports the notion of apparent OM reactivity as a dynamic ecosystem property, (ii) consolidates the distributions of RCM parameters, and (iii) provides quantitative constraints on how OM reactivity governs benthic biogeochemical cycling and exchange. Therefore, it provides important global constraints on the most plausible range of RCM parameters a and v and largely alleviates the difficulty of determining OM reactivity in RCM by constraining it to only one variable, i.e. the parameter a. It thus represents an important advance for model parameterization in data-poor areas.

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Section: Observational Datamentioning

confidence: 99%

Section: Boundary Conditionsmentioning

confidence: 99%

Section: Om Reactivity Controls On Sediment-water Interface Fluxes Patternsmentioning

confidence: 99%

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New insights into large-scale trends of apparent organic matter reactivity in marine sediments and patterns of benthic carbon transformation

et al. 2021

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“…Thus, this study provides quantitative evidence to include twilight zone C fixation rates in the marine C budget estimates. might be alternative C sources in the OMZs (Ragavan & Kumar, 2021). Therefore, it seems that dark C fixation can make OMZs intense and that chemoautotrophy in OMZs can be a significant part of the C cycling.…”

Section: Introductionmentioning

confidence: 99%

“…The OMZs might be favorable for chemoautotrophs since less energy is required to reduce inorganic C to organic C in anaerobic environments compared to aerobic environments (Hügler & Sievert, 2011; McCollom & Amend, 2005). Additionally, the sinking C to OMZs is insufficient to fulfill prokaryotic C demand and thus, there might be alternative C sources in the OMZs (Ragavan & Kumar, 2021). Therefore, it seems that dark C fixation can make OMZs intense and that chemoautotrophy in OMZs can be a significant part of the C cycling.…”

Section: Introductionmentioning

confidence: 99%

Contribution of Carbon Fixation Toward Carbon Sink in the Ocean Twilight Zone

Saxena

Sahoo

Nazirahmed

et al. 2022

Geophysical Research Letters

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Dark carbon (C) fixation in the ocean twilight zone plays a crucial role toward C sink, but its potential has not been tested sufficiently in experiments. Here we analyzed dark C fixation in the twilight zone of the Arabian Sea along with the primary production measurements in the euphotic zone. The average dark C fixation rates in the suboxic oxygen minimum zone (OMZ) waters were higher than that in the hypoxic OMZ waters, which could be explained by the preferential existence of chemoautotrophic ammonium oxidizers and anammox bacteria owing to NO2− maxima in the suboxic OMZ waters. This study supports a previous hypothesis of significant contribution of dark C fixation to sinking C fluxes in the OMZ of the Arabian Sea. Extrapolation of the measured dark C fixation rates to the global ocean ranged up to 7.4 Pg C y−1; amounting to ∼15% of the global ocean primary production.

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Spatial distribution characteristics and interaction effects of DOM and microbial communities in kelp cultivation areas

Huang,

Zan,

Shao

et al. 2024

Science of The Total Environment

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Potential role of priming effect in the open ocean oxygen minimum zones: an outlook

Cited by 5 publications

References 136 publications

New insights into large-scale trends of apparent organic matter reactivity in marine sediments and patterns of benthic carbon transformation

New insights into large-scale trends of apparent organic matter reactivity in marine sediments and patterns of benthic carbon transformation

Contribution of Carbon Fixation Toward Carbon Sink in the Ocean Twilight Zone

Spatial distribution characteristics and interaction effects of DOM and microbial communities in kelp cultivation areas

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