This subproject is part of the collaborative research centre RETAKE, one of the six consortia within the DAM research mission CDRmare with the scope of assessing CO₂ removal by alkalinity enhancement.
The overall goal of RETAKE is to study the potential, benefits and environmental risks of alkalinity enhancement (AE) in order to remove CO₂ from the atmosphere. The activity of CO₂ in seawater is reduced with increased ocean alkalinity, leading to an enhanced flux of CO₂ from the atmosphere into the ocean, which could effectively reduce atmospheric CO₂ concentrations.

Marine sediments will be supplemented with olivine and carbonate minerals in incubations and mesocosm experiments to simulate alkalinity enhancement scenarios. We will study the interactions and feedbacks between benthic weathering (geochemistry coordinated by Dr. Sonja Geilert, https://www.geomar.de/en/sgeilert) and microbial activities. For this purpose, we will analyse microbial community compositions by 16S RNA/DNA studies and quantify organisms of major microbial groups via CARD-FISH and qPCR. For selected samples of interest, we will use transcriptomics to capture potential shifts in gene expression caused by alkalinity enhancement through benthic weathering.

Team:

Geomicrobiology
Prof. Dr. Mirjam Perner (AP1.4 of RETAKE)
Rebecca Bährle - PhD student

Benthic Biogeochemistry
Dr. Andy Dale
Michael Fuhr - PhD student

Related publications/presentations:

Bährle, R., Böhnke-Brandt, R., Fuhr, M., Dale, A. and M. Perner (2024). Reactions of the microbial community in benthic alkalinity enhancement experiments. VAAM, Würzburg.

Fuhr, M., Wallmann, K., Dale, A. W. , Diercks, I., Kalapurakkal, H. T., Schmidt, M. , Sommer, S., Böhnke, S., Perner, M.und Geilert, S.(2023) Disentangling artificial and natural benthic weathering in organic rich Baltic Sea sediments.  Frontiers in Climate, 5 . Art.Nr. 1245580. DOI 10.3389/fclim.2023.1245580.

Diercks, I.,Geilert, S., Böhnke-Brandt, S., Dale, A.W., Fuhr, M., Perner, M. (2022). Interactions between microbial activity and enhanced benthic weathering of carbonate and olivine in the Baltic Sea. ePoster auf der VAAM Jahrestagung 2022

Diercks, I.,Geilert, S., Dale, A.W., Fuhr, M. and Perner, M. (2022). Interactions between microbial activity and enhanced benthic weathering in the Baltic Sea to analyse the potential, benefits and risks of a marine CDR strategy. YOUMARES13, Berlin.