Aarhus University Seal

CARMA - CARbon sequestration by Greenland’s Marine forests in a warming Arctic

This research project aims to test the hypothesis that burial of carbon (C) exported from Arctic marine forests (seaweed & seagrass) provides a globally relevant, and growing, contribution to C-sequestration in marine sediments – using Greenland as a case study.

The project is funded by the Independent Research Fund of Denmark and led by researchers from Aarhus University’s Department of Ecoscience and Department of Geoscience in cooperation with researchers from King Abdullah University of Science and Technology (KAUST), Saudi Arabia, Helmholtz Zentrum Geesthacht, Institute of Coastal Research, Germany and Max Planck institute, Germany.



  • Ross, F.W., Boyd, P.W., Filbee-Dexter, K., Watanabe, K., Ortega, A., Krause-Jensen, D., Lovelock, C., Sondak, C.F., Bach, L.T., Duarte, C.M. and Serrano, O., 2023. Potential role of seaweeds in climate change mitigation. Science of the Total Environment, p.163699. doi.org/10.1016/j.scitotenv.2023.163699
  • Ørberg SB, Duarte CM, Geraldi NR, Sejr M, Wegeberg S, Hansen JLS, Krause-Jensen D. 2023. Prevalent Fingerprint of Marine Macroalgae in Arctic surface sediments. Science of the Total Environment: 898. https://doi.org/10.1016/j.scitotenv.2023.165507
  • Filbee-Dexter, K., Pessarrodona, A., Duarte, C. M., Krause-Jensen, D., Hancke, K., Smale, D., & Wernberg, T. (2023). Seaweed forests are carbon sinks that may help mitigate CO2 emissions: a comment on Gallagher et al.(2022). ICES Journal of Marine Science, fsad107. https://doi.org/10.1093/icesjms/fsad107
  • Carlson, D. F., Vivó-Pons, A., Treier, U. A., Mätzler, E., Meire, L., Sejr, M., & Krause-Jensen, D. (2023). Mapping intertidal macrophytes in fjords in Southwest Greenland using Sentinel-2 imagery. Science of the Total Environment865, 161213. https://doi.org/10.1016/j.scitotenv.2022.161213
  • Ager, T. G., Krause-Jensen, D., Olesen, B., Carlson, D. F., Winding, M. H. S., & Sejr, M. K. (2023). Macroalgal habitats support a sustained flux of floating biomass but limited carbon export beyond a Greenland fjord. Science of The Total Environment, 162224. https://doi.org/10.1016/j.scitotenv.2023.162224


  • Krause-Jensen, Dorte, Hege Gundersen, Mats Björk, Martin Gullström, Martin Dahl, Maria E. Asplund, Christoffer Boström et al. "Nordic blue carbon ecosystems: status and outlook." Frontiers in Marine Science 9 (2022). https://doi.org/10.3389/fmars.2022.847544
  • Fragkopoulou, E., Serrão, E. A., De Clerck, O., Costello, M. J., Araújo, M. B., Duarte, C. M., ... & Assis, J. (2022). Global biodiversity patterns of marine forests of brown macroalgae. Global Ecology and Biogeography31(4), 636-648. https://doi.org/10.1111/geb.13450
  • Assis, J., Serrão, E. A., Duarte, C. M., Fragkopoulou, E., & Krause-Jensen, D. (2022). Major expansion of marine forests in a warmer Arctic. Frontiers in Marine Science 9, 850368  https://doi.org/10.3389/fmars.2022.850368
  • Kvile, K. Ø., Andersen, G. S., Baden, S. P., Bekkby, T., Bruhn, A., Geertz-Hansen, O., ... & Gundersen, H. (2022). Kelp forest distribution in the Nordic region. Frontiers in Marine Science, 887.  https://doi.org/10.3389/fmars.2022.850359
  • Bringloe, T. T., Fort, A., Inaba, M., Sulpice, R., Ghriofa, C. N., MolsMortensen, A., ... & Verbruggen, H. (2022). Whole genome population structure of North Atlantic kelp confirms high‐latitude glacial refugia. Molecular Ecology31: 6473-6488. https://doi.org/10.1111/mec.16714
  • Duarte, C. M.Gattuso, J.-P.Hancke, K.Gundersen, H.Filbee-Dexter, K.Pedersen, M. F.Middelburg, J. J.Burrows, M. T.Krumhansl, K. A.Wernberg, T.Moore, P.Pessarrodona, A.Ørberg, S. B.Pinto, I. S.Assis, J.Queirós, A. M.Smale, D. A.Bekkby, T.Serrão, E. A., & Krause-Jensen, D. (2022). Global estimates of the extent and production of macroalgal forestsGlobal Ecology and Biogeography001– 18https://doi.org/10.1111/geb.13515



[Translate to English:]

  • Krause-Jensen, D., Archambault, P., Assis, J., Bartsch, I., Bischof, K., Filbee-Dexter, K., ... & Duarte, C. M. (2020). Imprint of climate change on pan-Arctic marine vegetation. Frontiers in Marine Science, 7, 1-27. https://doi.org/10.3389/fmars.2020.617324
  • Ortega, A., Geraldi, N. R., Rua, R. D., Ørberg, S. B., Wesselmann, M., Krause-Jensen, D. & Duarte, C. M. (2020a). A DNA mini-barcode for marine macrophytes. Mol Ecol Resources, 20, 920–935. https://doi/10.1111/1755-0998.13164


  • Macreadie PI, Anton A, Raven JA, Beaumont N, Connolly RM, Friess DA, Kelleway JJ, Kennedy H, Kuwae T,
Lavery PS, Lovelock CE, Smale DA, Apostolaki ET, Atwood TB, Baldock J, Bianchi TS, Chmura GL, Eyre BD, Fourqurean JW, Hall-Spencer JM, Huxham M, Hendriks IE, Krause-Jensen D, Laffoley D, Luisetti T, Marbà N, Masque P, McGlathery KJ, Megonigal JP, Murdiyarso D, Russell BD, Santos R, Serrano O, Silliman BR, Watanabe K, Duarte CM. 2019. The Future of Blue Carbon Science. Nature Communications 10: 3998. doi.org/10.1038/s41467-019-11693-w (open access) (open access)
  • Ortega A, Geraldi NR, Alam I, Kamau AA, Acinas SG, Logares R, Gasol JM, Massana R, Krause-Jensen D, Duarte CM. 2019. Important contribution of macroalgae to oceanic carbon sequestration. Nature Geoscience. Doi: 10.1038/s41561-019-0421-8.
  • Krause-Jensen D, Sejr M, Bruhn A, Rasmussen MB, Christensen PB, Hansen JLS, Duarte CM, Bruntse G, Wegeberg S. 2019. Deep penetration of kelps offshore along the west coast of Greenland. Frontiers in Marine Science 6:375. doi: 10.3389/fmars.2019.00375 (open access)
  • Queirós AM, Stephens N, Widdicombe S, Tait K, McCoy SJ, Ingels J, Rühl S, Airs R, Beesley A, Carnovale G, Cazenave1 P, Dashfield S, Hua E, Jones M, Lindeque P, McNeill CL, Nunes J, Parry H, Pascoe C, Widdicombe C, Smyth T, Atkinson A, Krause-Jensen D, Somerfield PJ. 2019. Connected macroalgal-sediment systems: blue carbon and foodwebs in the deep coastal ocean. Ecological Monographs, e01366. (open access)
  • Saderne, V., P. I. Macreadie, D. T. Maher, J. J. Middelburg, O. Serrano, H. Almahasheer, A. Arias-Ortiz, M. Cusack, B. D. Eyre, J. Fourqurean, H. Kennedy, D. Krause-Jensen, T. Kuwae, P. Lavery, C. E. Lovelock, N. Marba, P. Masqué, M. A. Mateo, I. Mazarrasa, K. J. McGlathery, M. P. J. Oreska, C. J. Sanders, I. R. Santos, J. M. Smoak, T. Tanaya, K. Watanabe, C. M. Duarte. 2019. Role of carbonate burial in “Blue Carbon” budgets. Nature communications. https://doi.org/10.1038/s41467-019-08842-6. (open access)
  • Sanz-Martín M, Hendriks IE, Carstensen J, Marba N, Krause-Jensen D, Sejr MK, Duarte CM. 2019. Continuous photoperiod of the Artic summer stimulates the photosynthetic response of some marine macrophytes. Aquatic Botany 158: 103126. https://doi.org/10.1016/j.aquabot.2019.06.005


  • Krause-Jensen D, Lavery P, Serrano O, Marbá N, Masque P, Duarte CM. 2018 Sequestration of macroalgal carbon: the elephant in the Blue Carbon room. Biol. Lett. 14: 20180236. dx.doi.org/10.1098/rsbl.2018.0236 (open access)

Other Outreach


  • Ørberg, S., Duarte, C., Geraldi, N., Sejr, M., Wegeberg, S., Hansen, J., Krause-Jensen, D. (2023). Tracing macroalgae in Arctic sediments using environmental DNA. P. 28-30 in Christensen T.R. & Arndal M.F. GEM Annual report Card 2022. Zenodo. https://doi.org/10.5281/zenodo.8141553 DCE – Danish Centre for Environment and Energy, Aarhus University, 52 pp.


  • Krause-Jensen, D and Duarte, CM 2021. Climate change and the expansion of marine forests around Greenland’s coast. Extreme-E Global Legacy Workshop. Presentation at Kangerlussuaq 28. August 2021. (Presented by CM Duarte) https://www.extreme-e.com/en/legacy-projects/greenland
  • Krause-Jensen D. 2021. “Wild Macroalgae” Presentation at the virtual conference “Blue Carbon – a new frontier for conservation? Building ambition ahead of COP26” organized by the Blue Marine Foundation, 9. June 2021. https://www.bluemarinefoundation.com/projects/blue-carbon/ (Direct link to my presentation: https://www.youtube.com/watch?v=N1FSCDRQJ_o&t=29s; Direct link to online conference: https://www.youtube.com/watch?v=Ibg59z7Ua48&t=8s)
  • Ørberg, S. 2021. Fingerprint of Marine Forests in Arctic surface sediments. ASLO Aquatic Sciences meeting, On-line, June 22-27, 2021
  • Krause-Jensen D. 2021. Marine forests and blue carbon. Lecture Series 2021 - Department of Biology, University of Southern Denmark, On-line, February 5, 2021
  • Krause-Jensen, D. 2021. Fate of macroalgae in the natural habitat. The National Academies of Science, Engineering and Medicine’s (NASEM)  Workshop on Ocean-based CDR Opportunities and Challenges - Part 3: Ecosystem Recovery & Seaweed Cultivation. Links: A Research Strategy for Ocean Based Carbon Dioxide Removal and Sequestration, project website Board, you can sign up for our listserv here (in the “Connect with Us” box).   
  • Krause-Jensen D. 2021. ‘Changing seaweed along Greenland’s coasts and beyond and Blue Carbon perspectives’ ARCTOS on-line Colloquium “Macroalgae of high latitudes. 19.-20. January 2021.



  • Krause-Jensen D & Duarte CM. Coordination of the Euromarine foresight workshop: “The role of macroalgae in the global carbon cycle”, Carmen de la Victoria, Granada, April 7-10, 2019.
  • Krause-Jensen D & Duarte C. 2019. Macroalgae in the Blue Carbon context – including seaweed farming perspectives. Presentation at Blue Carbon International workshop in Copenhagen 9-13. September 2019.
  • Krause-Jensen D & Holmer M. 2019. Blue Forests in Denmark and Greenland – Status and knowledge gaps. Presentation at Blue Carbon International workshop in Copenhagen 9-13. September 2019.
  • Krause-Jensen D. 2019. Surveys of kelp and tidal algae in Greenland. Presentation at MARFOR (Marine forests) workshop, Faro, 27-28 February 2019.
  • Krause-Jensen D. 2019. The elephant in the blue carbon room - the role of macroalgae: status and aims. Final workshop for the Nordic blue carbon project, 21-22 November 2019, Miljødirektoratet, Helsfyr, Oslo
  • Krause-Jensen D. 2019. Nordic blue forests- Status, possibilities and challenges. Nordic ocean and climate workshop: Priorities for Nordic countries in International work. May 13-14 2019, Oslo.

The project is supported by The Independent Research Fund of Denmark (DFF). Dorte Krause-Jensen from Aarhus University, Department of Ecoscience is in charge of the project in collaboration with Carlos Duarte from King Abdullah University of Science and Technology (KAUST), Saudi Arabien. The project takes place in a close collaboration with a core project group consisting of Sarah Backmann Ørberg and Mikael Sejr from Aarhus University, Department of Ecoscience, Marit-Solveig Seidenkrantz, Aarhus University, Department of Geoscience, Daniel Frazier Carlson Helmholtz Zentrum Geesthacht, Institute of Coastal Research, Germany and Thomas Larsen, and Max Planck Institute, Germany. In addition to the core group, several colleagues and students also participate in the project.