Biogel scavenging slows the sinking of organic particles to the ocean depths
One of Earth's largest carbon fluxes is driven by particles made from photosynthetically fixed matter, which aggregate and sink into the deep ocean. While biodegradation is known to reduce this vertical flux, the biophysical processes that control particle sinking speed are not well understood. Here, we use a vertical millifluidic column to video-track single particles and find that biogels scavenged by particles during sinking significantly reduce the particles' sinking speed, slowing them by up to 45% within one day. Combining observations with a mathematical model, we determine that the mechanism for this slowdown is a combination of increased drag due to the formation of biogel tendrils and increased buoyancy due to the biogel's low density. Because biogels are pervasive in the ocean, we propose that by slowing the sinking of organic particles they attenuate the vertical carbon flux in the ocean.
Authors
- Uria Alcolombri (ORCID: https://orcid.org/0000-0003-3561-5091)
- Uwe Sauer (ORCID: https://orcid.org/0000-0002-5923-0770)
- Sam Charlton (ORCID: https://orcid.org/0000-0002-0091-5134)
- Roman Stocker (ORCID: https://orcid.org/0000-0002-3199-0508)
- Andreas Sichert (ORCID: https://orcid.org/0000-0002-1386-5535)
- Eleonora Secchi (ORCID: https://orcid.org/0000-0002-0949-9085)
- Alon Nissan (ORCID: https://orcid.org/0000-0003-1300-5591)
- Anupam Sengupta (ORCID: https://orcid.org/0000-0001-5592-7864)
- Kang Soo Lee (ORCID: https://orcid.org/0000-0001-5977-4770)
- Jonasz Słomka (ORCID: https://orcid.org/0000-0002-7097-5810)
- Dieter A. Baumgartner (ORCID: https://orcid.org/0000-0003-4775-5884)
- François J. Peaudecerf (ORCID: https://orcid.org/0000-0003-0295-4556)
- Isobel Short
Institutions
- Centre National de la Recherche Scientifique (FR)
- University of Luxembourg (LU)
- Hebrew University of Jerusalem (IL)
- ETH Zurich (CH)
- Institut de Physique de Rennes (FR)
- Ulsan National Institute of Science and Technology (KR)
- Université de Rennes (FR)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-04-07
- DOI
- https://doi.org/10.1038/s41467-025-57982-5
- Citations
- 3
- Primary Topic
- Marine and coastal ecosystems
- Type
- article
- Field-Weighted Citation Impact
- 5.38
Funders
- National Science Foundation
- Gordon and Betty Moore Foundation
- European Commission
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Fonds National de la Recherche Luxembourg
- Council for Higher Education