Project Overview
SEA-Quester is an interdisciplinary research initiative aimed at advancing our understanding of blue carbon sequestration in polar and sub‐polar marine ecosystems (Home | SEA-Quester : SEA-Quester). By integrating state‐of‐the‐art field observations, remote sensing, and mechanistic, trait‐based modelling, the project seeks to quantify the processes governing carbon capture and storage in marine sediments. A central objective is to establish a robust, process‐based blue carbon accounting framework that elucidates the interactions between primary production, carbon export, and sedimentary burial under rapidly changing climatic conditions.
Aims and Research Questions
The project is driven by several core research questions:
Quantification of Sedimentary Carbon Sequestration: What are the rates and temporal dynamics of carbon burial in marine sediments from pre‐historic to modern times?
Environmental Modulation of Blue Carbon: How do climatic and environmental variables—such as water temperature, freshwater flux, sea‐ice cover, and productivity—influence the magnitude and persistence of sedimentary carbon stocks?
Differentiation of Carbon Sources: What is the relative contribution of reworked fossil carbon versus newly produced organic carbon in sediment reservoirs, and how do these proportions shift in response to climate-induced changes in marine ecosystems?
Within the SEA-Quester framework, a significant component of the work undertaken at Aarhus University is encapsulated in the following two tasks.
Task 1: Quantifying Sedimentary Carbon Sequestration:
This task involves a detailed geochemical analysis of sediment cores collected from diverse marine environments. The total organic and inorganic carbon will be measured to determine past carbon burial rates. Techniques such as stable isotope analysis, pyrolysis, and diagnostic biomarker assessments (including phytosterols and highly branched isoprenoids [HBIs]) will be employed to differentiate between different carbon sources. These analyses will yield time-resolved estimates of carbon accumulation in the sea-floor, allowing for an evaluation of how carbon sequestration has varied over millennia in response to natural and anthropogenic forcing.
Task 2: Linking Climatic Conditions to Carbon Sequestration:
This task aims to correlate the quantitative data derived from Task 2 with paleoenvironmental indicators. By analysing microfossil assemblages (foraminifera, diatoms, and dinoflagellate cysts), inorganic geochemical proxies (X-ray fluorescence, Mg/Ca ratios, stable isotopes), and organic biomarkers in the same sediment cores, the team will reconstruct past environmental conditions such as sea-surface temperature, freshwater influx, and sea-ice extent. This integrated approach will address the question: Which climatic conditions are most conducive to enhanced carbon burial, and how might future climate change scenarios alter these processes?
Project participants
Christof Pearce (AU Main contact and WP4-5 co-lead), Marit-Solveig Seidenkrantz, Henrieka Detlef, Sarah Ferrandin, Hamed Sanei
