Total alkalinity production in a mangrove ecosystem reveals an overlooked Blue Carbon component

Saderne, Vincent; Fusi, Marco; Thomson, Timothy; Dunne, Aislinn; Mahmud, Fatima; Roth, Florian; Carvalho, Susana; Duarte, Carlos M.

Abstract

Mangroves have the capacity to sequester organic carbon (Corg) in their sediments permanently. However, the carbon budget of mangroves is also affected by the total alkalinity (TA) budget. Principally, TA emitted from carbonate sediment dissolution is a perennial sink of atmospheric CO2. The assessment of the TA budget of mangrove carbonate sediments in the Red Sea revealed a large TA emission of 403 ± 17 mmol m−2 d−1, independent of light, seasons, or the presence of pneumatophores, compared to −36 ± 10 mmol m−2 d−1 in lagoon sediment. We estimate the TA emission from carbonate dissolution in Red Sea mangroves supported a CO2 uptake of 345 ± 15 gC m−2 yr−1, 23‐fold the Corg burial rate of 15 gC m−2 yr−1. The focus on Corg burial in sediments may substantially underestimate the role of mangroves in CO2 removal. Quantifying the role of mangroves in climate change mitigation requires carbonate dissolution to be included in assessments.

Citation

Saderne, V., Fusi, M., Thomson, T., Dunne, A., Mahmud, F., Roth, F., Carvalho, S., & Duarte, C. M. (2021). Total alkalinity production in a mangrove ecosystem reveals an overlooked Blue Carbon component. Limnology and Oceanography Letters, 6(2), 61-67. https://doi.org/10.1002/lol2.10170

• Journal Article Type: Letter
• Acceptance Date: Sep 21, 2020
• Online Publication Date: Oct 16, 2020
• Publication Date: 2021-04
• Deposit Date: Oct 19, 2020
• Publicly Available Date: Oct 19, 2020
• Journal: Limnology and Oceanography Letters
• Print ISSN: 2378-2242
• Electronic ISSN: 2378-2242
• Publisher: Wiley Open Access
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Issue: 2
• Pages: 61-67
• DOI: https://doi.org/10.1002/lol2.10170
• Public URL: http://researchrepository.napier.ac.uk/Output/2694259