First assessment of blue carbon stocks, sequestration rates and potential sources since 1900 at Arguin Island (Mauritania)

Seagrass meadows at Arguin Island, Banc d'Arguin National Park (Mauritania), store significantly more organic carbon (OC) than adjacent unvegetated sediments, with stocks averaging 27.8 ± 7.14 Mg C ha⁻¹—five times higher—and sequestration rates of up to 12.3 g C m⁻² year⁻¹ over the past century. This study marks the first in situ assessment of blue carbon dynamics in Western African seagrass beds, providing critical data for underrepresented regions. Using sedimentary environmental DNA (eDNA) and chronostratigraphy, researchers identified seagrass species as the primary OC source since 1900, with Zostera noltei meadows showing greater diversity than Cymodocea nodosa. Bare sediments were dominated by diatoms. The findings highlight eDNA's potential to trace organic matter provenance, advancing understanding of carbon cycling in blue carbon ecosystems.

Martins, M., Abrantes, F., Aires, T., Rautenbach, S., Engelen, A. H., Encarnação, J., Abecasis, D., Gandega, C., Magalhães, V., Brahim, K., Ebaye, S., Barusseau, J.-P., Freiwald, A., de los Santos, C. B., Serrão, E. A., & Santos, R. (2025). First assessment of blue carbon stocks, sequestration rates and potential sources since 1900 at Arguin Island (Mauritania). Aquatic Sciences, 87(4). https://doi.org/10.1007/s00027-025-01211-0