Engel A, Thoms S, Riebesell U, Rochelle-Newall E, Zondervan I
Emiliania huxleyi, Bacteria, co2, DOC, mesocosm, Bergen, 11 m3, Espegrend, Norway
The formation and sinking of biogenic particles mediate verticalmass fluxes and drive elemental cycling in the ocean1. Whereasmarine sciences have focused primarily on particle production byphytoplankton growth, particle formation by the assembly oforganic macromolecules has almost been neglected2,3. Here weshow, by means of a combined experimental and modellingstudy, that the formation of polysaccharide particles is animportant pathway to convert dissolved into particulate organiccarbon during phytoplankton blooms, and can be described interms of aggregation kinetics. Our findings suggest that aggregationprocesses in the ocean cascade from the molecular scale up tothe size of fast-settling particles, and give new insights into thecycling and export of biogeochemical key elements such ascarbon, iron and thorium.