Unveiling pelagic-benthic coupling associated with the biological carbon pump in the Fram Strait (Arctic Ocean)

• Published in: Nature communications Vol. 16; no. 1; pp. 840 - 12
• Main Authors: Ramondenc, Simon, Eveillard, Damien, Metfies, Katja, Iversen, Morten H., Nöthig, Eva-Maria, Piepenburg, Dieter, Hasemann, Christiane, Soltwedel, Thomas
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20.01.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 704/158/2463; 704/47/4113; 704/829/826; Animals; Arctic Regions; Bacillariophyceae; Biodiversity and Ecology; Bioinformatics; Biological activity; Carbon; Carbon - metabolism; Carbon Cycle; Chaetoceros socialis; Community composition; Computer Science; Continental interfaces, environment; Coupling; Critical components; Deep sea; Diatoms - classification; Diatoms - genetics; Diatoms - metabolism; Ecological function; Ecosystem; Environmental Sciences; Exports; Fluctuations; Geologic Sediments; Humanities and Social Sciences; Marine microorganisms; multidisciplinary; Ocean floor; Ocean surface; Oceans and Seas; Organic carbon; Organic matter; Parasites; Phylogeny; Plankton; Plankton - genetics; Plankton - metabolism; Science; Science (multidisciplinary); Sciences of the Universe; Sea ice; Seawater - chemistry; Settling; Spores; Straits; Arctic Regions; Arctic Ocean; Fram Strait
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-55221-x

Settling aggregates transport organic matter from the ocean surface to the deep sea and seafloor. Though plankton communities impact carbon export, how specific organisms and their interactions affect export efficiency is unknown. Looking at 15 years of eDNA sequences (18S-V4) from settling and sedimented organic matter in the Fram Strait, here we observe that most phylogenetic groups were transferred from pelagic to benthic ecosystems. Chaetoceros socialis , sea-ice diatoms, Radiolaria, and Chaetognatha are critical components of vertical carbon flux to 200 m depth. In contrast, the diatom C. socialis alone is essential for the amount of organic carbon reaching the seafloor. Spatiotemporal changes in community composition show decreasing diatom abundance during warm anomalies, which would reduce the efficiency of a diatom-driven biological carbon pump. Interestingly, several parasites are also tightly associated with carbon flux and show a strong vertical connectivity, suggesting a potential role in sedimentation processes involving their hosts, especially through interactions with resting spores, which could have implications for pelagic-benthic coupling and overall ecosystem functioning. Examining 15 years of data in the Arctic, this study shows that plankton, including diatoms and parasites, play key roles in exporting carbon to the seafloor. Species like Chaetoceros socialis are crucial for carbon flux and pelagic-benthic coupling.