Organic carbon recycling in Baltic Sea sediments – An integrated estimate on the system scale based on in situ measurements

Madeleine M. Nilsson*, M. Kononets, N. Ekeroth, L. Viktorsson, A. Hylén, S. Sommer, O. Pfannkuche, E. Almroth-Rosell, D. Atamanchuk, J.H. Andersson, P. Roos, A. Tengberg, Per O. J. Hall

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

In situ measured benthic fluxes of dissolved inorganic carbon (DIC), a proxy for organic carbon (OC) oxidation or recycling rates, are used together with burial rates based on measured sediment accumulation rates (SAR) and vertical distribution of OC in the sediment solid phase to construct a benthic OC budget for the Baltic Sea system. The large variability in recycling rates (4.3 ± 0.87–33 ± 17 mmol C m−2 d−1) and burial rates (1.2 ± 0.8–5.9 ± 1.8 mmol C m−2 d−1) between different sub-basins and between different depositional areas within the basins is accounted for in the budget. Our results indicate that sediments in the Baltic Sea have much higher recycling rates and lower burial rates of OC than previously found. The sediment budget calculations show that 22 ± 7.8 Tg C yr−1 of OC is recycled to the water column due to organic matter oxidation, while long term burial amounts to 1.0 ± 0.3 Tg C yr−1. For the Baltic Sea as a whole, 96% of the particulate OC (POC) deposited on the sea floor (23 ± 7.8 Tg C yr−1; the sum of recycling and burial) is recycled back to the water column. However, the burial efficiency (i.e. the fraction buried of the total deposition) shows large variability between the different basins (2.5–16%). The total benthic POC deposition is approximately 20% higher than the estimated POC source originating from primary production in the water column and riverine input. This difference is likely within the uncertainty range of our budget calculations, however it indicates that the POC sources might be underestimated. The results from this study enhance the understanding of OC delivery, deposition and cycling in the Baltic Sea, and help improving existing Baltic OC budgets.
Original languageEnglish
JournalMarine Chemistry
Volume209
Pages (from-to)81-93
ISSN0304-4203
DOIs
Publication statusPublished - 2019

Keywords

  • Carbon cycle
  • Sediment
  • In situ DIC flux
  • Baltic Sea

Cite this

Nilsson, M. M., Kononets, M., Ekeroth, N., Viktorsson, L., Hylén, A., Sommer, S., ... Hall, P. O. J. (2019). Organic carbon recycling in Baltic Sea sediments – An integrated estimate on the system scale based on in situ measurements. Marine Chemistry, 209, 81-93. https://doi.org/10.1016/j.marchem.2018.11.004
Nilsson, Madeleine M. ; Kononets, M. ; Ekeroth, N. ; Viktorsson, L. ; Hylén, A. ; Sommer, S. ; Pfannkuche, O. ; Almroth-Rosell, E. ; Atamanchuk, D. ; Andersson, J.H. ; Roos, P. ; Tengberg, A. ; Hall, Per O. J. / Organic carbon recycling in Baltic Sea sediments – An integrated estimate on the system scale based on in situ measurements. In: Marine Chemistry. 2019 ; Vol. 209. pp. 81-93.
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title = "Organic carbon recycling in Baltic Sea sediments – An integrated estimate on the system scale based on in situ measurements",
abstract = "In situ measured benthic fluxes of dissolved inorganic carbon (DIC), a proxy for organic carbon (OC) oxidation or recycling rates, are used together with burial rates based on measured sediment accumulation rates (SAR) and vertical distribution of OC in the sediment solid phase to construct a benthic OC budget for the Baltic Sea system. The large variability in recycling rates (4.3 ± 0.87–33 ± 17 mmol C m−2 d−1) and burial rates (1.2 ± 0.8–5.9 ± 1.8 mmol C m−2 d−1) between different sub-basins and between different depositional areas within the basins is accounted for in the budget. Our results indicate that sediments in the Baltic Sea have much higher recycling rates and lower burial rates of OC than previously found. The sediment budget calculations show that 22 ± 7.8 Tg C yr−1 of OC is recycled to the water column due to organic matter oxidation, while long term burial amounts to 1.0 ± 0.3 Tg C yr−1. For the Baltic Sea as a whole, 96{\%} of the particulate OC (POC) deposited on the sea floor (23 ± 7.8 Tg C yr−1; the sum of recycling and burial) is recycled back to the water column. However, the burial efficiency (i.e. the fraction buried of the total deposition) shows large variability between the different basins (2.5–16{\%}). The total benthic POC deposition is approximately 20{\%} higher than the estimated POC source originating from primary production in the water column and riverine input. This difference is likely within the uncertainty range of our budget calculations, however it indicates that the POC sources might be underestimated. The results from this study enhance the understanding of OC delivery, deposition and cycling in the Baltic Sea, and help improving existing Baltic OC budgets.",
keywords = "Carbon cycle, Sediment, In situ DIC flux, Baltic Sea",
author = "Nilsson, {Madeleine M.} and M. Kononets and N. Ekeroth and L. Viktorsson and A. Hyl{\'e}n and S. Sommer and O. Pfannkuche and E. Almroth-Rosell and D. Atamanchuk and J.H. Andersson and P. Roos and A. Tengberg and Hall, {Per O. J.}",
year = "2019",
doi = "10.1016/j.marchem.2018.11.004",
language = "English",
volume = "209",
pages = "81--93",
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Nilsson, MM, Kononets, M, Ekeroth, N, Viktorsson, L, Hylén, A, Sommer, S, Pfannkuche, O, Almroth-Rosell, E, Atamanchuk, D, Andersson, JH, Roos, P, Tengberg, A & Hall, POJ 2019, 'Organic carbon recycling in Baltic Sea sediments – An integrated estimate on the system scale based on in situ measurements', Marine Chemistry, vol. 209, pp. 81-93. https://doi.org/10.1016/j.marchem.2018.11.004

Organic carbon recycling in Baltic Sea sediments – An integrated estimate on the system scale based on in situ measurements. / Nilsson, Madeleine M.; Kononets, M.; Ekeroth, N.; Viktorsson, L.; Hylén, A.; Sommer, S.; Pfannkuche, O.; Almroth-Rosell, E.; Atamanchuk, D.; Andersson, J.H.; Roos, P.; Tengberg, A.; Hall, Per O. J.

In: Marine Chemistry, Vol. 209, 2019, p. 81-93.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Organic carbon recycling in Baltic Sea sediments – An integrated estimate on the system scale based on in situ measurements

AU - Nilsson, Madeleine M.

AU - Kononets, M.

AU - Ekeroth, N.

AU - Viktorsson, L.

AU - Hylén, A.

AU - Sommer, S.

AU - Pfannkuche, O.

AU - Almroth-Rosell, E.

AU - Atamanchuk, D.

AU - Andersson, J.H.

AU - Roos, P.

AU - Tengberg, A.

AU - Hall, Per O. J.

PY - 2019

Y1 - 2019

N2 - In situ measured benthic fluxes of dissolved inorganic carbon (DIC), a proxy for organic carbon (OC) oxidation or recycling rates, are used together with burial rates based on measured sediment accumulation rates (SAR) and vertical distribution of OC in the sediment solid phase to construct a benthic OC budget for the Baltic Sea system. The large variability in recycling rates (4.3 ± 0.87–33 ± 17 mmol C m−2 d−1) and burial rates (1.2 ± 0.8–5.9 ± 1.8 mmol C m−2 d−1) between different sub-basins and between different depositional areas within the basins is accounted for in the budget. Our results indicate that sediments in the Baltic Sea have much higher recycling rates and lower burial rates of OC than previously found. The sediment budget calculations show that 22 ± 7.8 Tg C yr−1 of OC is recycled to the water column due to organic matter oxidation, while long term burial amounts to 1.0 ± 0.3 Tg C yr−1. For the Baltic Sea as a whole, 96% of the particulate OC (POC) deposited on the sea floor (23 ± 7.8 Tg C yr−1; the sum of recycling and burial) is recycled back to the water column. However, the burial efficiency (i.e. the fraction buried of the total deposition) shows large variability between the different basins (2.5–16%). The total benthic POC deposition is approximately 20% higher than the estimated POC source originating from primary production in the water column and riverine input. This difference is likely within the uncertainty range of our budget calculations, however it indicates that the POC sources might be underestimated. The results from this study enhance the understanding of OC delivery, deposition and cycling in the Baltic Sea, and help improving existing Baltic OC budgets.

AB - In situ measured benthic fluxes of dissolved inorganic carbon (DIC), a proxy for organic carbon (OC) oxidation or recycling rates, are used together with burial rates based on measured sediment accumulation rates (SAR) and vertical distribution of OC in the sediment solid phase to construct a benthic OC budget for the Baltic Sea system. The large variability in recycling rates (4.3 ± 0.87–33 ± 17 mmol C m−2 d−1) and burial rates (1.2 ± 0.8–5.9 ± 1.8 mmol C m−2 d−1) between different sub-basins and between different depositional areas within the basins is accounted for in the budget. Our results indicate that sediments in the Baltic Sea have much higher recycling rates and lower burial rates of OC than previously found. The sediment budget calculations show that 22 ± 7.8 Tg C yr−1 of OC is recycled to the water column due to organic matter oxidation, while long term burial amounts to 1.0 ± 0.3 Tg C yr−1. For the Baltic Sea as a whole, 96% of the particulate OC (POC) deposited on the sea floor (23 ± 7.8 Tg C yr−1; the sum of recycling and burial) is recycled back to the water column. However, the burial efficiency (i.e. the fraction buried of the total deposition) shows large variability between the different basins (2.5–16%). The total benthic POC deposition is approximately 20% higher than the estimated POC source originating from primary production in the water column and riverine input. This difference is likely within the uncertainty range of our budget calculations, however it indicates that the POC sources might be underestimated. The results from this study enhance the understanding of OC delivery, deposition and cycling in the Baltic Sea, and help improving existing Baltic OC budgets.

KW - Carbon cycle

KW - Sediment

KW - In situ DIC flux

KW - Baltic Sea

U2 - 10.1016/j.marchem.2018.11.004

DO - 10.1016/j.marchem.2018.11.004

M3 - Journal article

VL - 209

SP - 81

EP - 93

JO - Marine Chemistry

JF - Marine Chemistry

SN - 0304-4203

ER -