Blue Carbon production, export and sequestration in emerging polar ecosystems

Project Information

SEA-Quester

Grant agreement ID: 101136480

DOI

10.3030/101136480

EC signature date 15 November 2023

Start date 1 February 2024

End date 31 January 2028

Funded under

• Food, Bioeconomy Natural Resources, Agriculture and Environment

Total cost

No data

EU contribution

€ 5 111 918,90

Coordinated by

DANMARKS TEKNISKE UNIVERSITET
Denmark

Periodic Reporting for period 1 - SEA-Quester (Blue Carbon production, export and sequestration in emerging polar ecosystems)

Reporting period: 2024-02-01 to 2025-07-31

Summary of the context and overall objectives of the project

SEA-Quester addresses one of the most pressing questions in climate science: how will ongoing changes in polar and sub-polar oceans alter the ocean’s role in taking up, exporting and sequestering carbon. Polar regions are experiencing rapid environmental changes including warming, retreat of sea ice and glaciers, and changing carbon chemistry and hydrography, which fundamentally reshape both coastal and pelagic ecosystems and the cycling of organic matter. In addition, maritime activities such as fishing and shipping interact with climate change further impacting the biological processes that are the basis of carbon uptake and sequestration. Because polar ecosystems play a disproportionate role in the global carbon cycle, changes here have the potential to affect the global ocean’s capacity to store atmospheric CO2. However, our current understanding of the interaction and feedback between environment, biodiversity and carbon sequestration in polar oceans is weak, which hampers the efforts to predict the future of polar uptake and sequestration of carbon.

SEA-Quester tackles the knowledge gaps in polar carbon through a combination of 1) field work investigating carbon storage and fluxes from coastal ecosystems to open ocean, 2) paleo-oceanographic observations establishing long-term links between environment and carbon burial and 3) trait-based modelling used to quantify the residence time of sequestered carbon globally. The main objectives of SEA-Quester are:

• To document the biodiversity, primary production and function of emerging polar and sub-polar marine ecosystems and to quantify their carbon sequestration – accounting for biomasses, fluxes and residence times of carbon.
• To strengthen the predictive skills of models through trait-based approaches that build on a better understanding of the interactions between functional biodiversity and carbon sequestration, and through assessing the past (paleo-oceanographic) interactions between organisms and their environment.
• To explore the interacting effects of climate change, anthropogenic stressors, carbon sequestration, oxygen demand and nutrient supply.
• To provide a rigorous means of quantifying i) marine carbon sequestration and ii) trade-offs between harvesting marine biomass and its net carbon sequestration that can be used to map, evaluate and compare blue carbon stocks and their potential, and to assess the impacts of conservation vs. other actions.
• To develop observations and monitoring of blue carbon within the framework of Essential Ocean Variables (EOVs).
• To support local, national and EU level policy-makers and management authorities on decisions regarding biodiversity, blue carbon, sequestration and human activities in emerging polar and sub-polar ecosystems as well as to promote ocean literacy with focus on blue carbon.

The results will improve our ability to sustainable manage the polar oceans, accounting for the effects of biomass and biodiversity losses for ocean's ability to sequester carbon and developing better predictions of biologically-mediated carbon uptake, export and sequestration in future.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

During the first 18 months of the project, SEA-Quester efforts have focused on identifying existing data, conducting field work for new data collections and development of process understanding, as well as on developing the trait-based modelling approaches. The main achievements include:

* Development of remote sensing algorithms to identify and quantify phytoplankton functional groups from space
* Quantification of structural and functional biodiversity of littoral communities in Arctic fjords and their relation to environmental factors
* Conducting ship-board experiments to investigate the fate of the primary production originating from ice vs. pelagic phytoplankton
* Sampling for zooplankton vertical day/night distribution and metabolic rates to understand their role in the biological carbon pump
* Quantifying how the composition and size of aggregates control their settling velocities
* Collecting new paleo-oceanographic cores, analyzing the existing cores and sampling for modern sediments to understand the interaction between environmental variables and sediment burial and fluxes
* Investigating seasonal development of pelagic and benthic processes and coupling in relation to environmental factors
* Sampling for carbon chemistry in the Arctic fjords to understand the impact of melting glaciers
* Developing the trait-based models NUM and SISSOMA to better represent zooplankton processes in the carbon export and sequestration

This work forms the basis for analyzing the interactions between environmental factors (focusing on the effect of diminishing ice), pelagic and benthic biodiversity and productivity, and carbon sequestration as well as its representation in models, to be performed during the next reporting period.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

As SEA-Quester is still in an early phase, the main analysis and synthesis of the collected experimental and field remains to be done. However, SEA-Quester has already produced some important advances including:

* Better quantification of temperature-dependent microbial activity, zooplankton-mediated aggregate fragmentation and stoichiometric transformation of sinking aggregates - results that go beyond the current state of the art by mechanistically linking microbial and zooplankton processes to aggregate characteristics and carbon flux efficiency.
* Quantification of increased amounts of heavy metals in benthic primary producers of an Arctic fjord, originating from a climate-induced glacial and terrestrial run-off. This has not been previously observed, and might lead to bioaccumulation of metals in higher trophic levels and cause bio-economic implications, such as the implementation of mari-cultures.
* Recommendations to scientific community trying to rectify the interpretation of “carbon sequestration” where in the science community it has effectively come to mean “carbon turnover” rather than “carbon offset” as originally intended by the IPCC.