Natural iron fertilization by shallow hydrothermal sources fuels diazotroph blooms in the ocean

• 成果类型: Article
• 署名作者: Bonnet, Sophie; Guieu, Cecile; Taillandier, Vincent; Boulart, Cedric; Bouruet-Aubertot, Pascale; Gazeau, Frederic; Scalabrin, Carla; Bressac, Matthieu; Knapp, Angela N.; Cuypers, Yannis; Gonzalez-Santana, David; Forrer, Heather J.; Grisoni, Jean-Michel; Grosso, Olivier; Habasque, Jeremie; Jardin-Camps, Mercedes; Leblond, Nathalie; Le Moigne, Frederic A. C.; Lebourges-Dhaussy, Anne; Lory, Caroline; Nunige, Sandra; Pulido-Villena, Elvira; Rizzo, Andrea L.; Sarthou, Geraldine; Tilliette, Chloe
• 署名单位: Centre National de la Recherche Scientifique (CNRS); Aix-Marseille Universite; Institut de Recherche pour le Developpement (IRD); Sorbonne Universite; Centre National de la Recherche Scientifique (CNRS); Centre National de la Recherche Scientifique (CNRS); CNRS - Institute of Ecology & Environment (INEE); Sorbonne Universite; Institut de Recherche pour le Developpement (IRD); Museum National d'Histoire Naturelle (MNHN); Sorbonne Universite; Centre National de la Recherche Scientifique (CNRS); Universite de Bretagne Occidentale; Ifremer; Centre National de la Recherche Scientifique (CNRS); CNRS - National Institute for Earth Sciences & Astronomy (INSU); State University System of Florida; Florida State University; Universite de Bretagne Occidentale; Centre National de la Recherche Scientifique (CNRS); Ifremer; Institut de Recherche pour le Developpement (IRD); CNRS - Institute of Ecology & Environment (INEE); Universidad de Las Palmas de Gran Canaria; Sorbonne Universite; Istituto Nazionale Geofisica e Vulcanologia (INGV); University of Milano-Bicocca
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-9867
• DOI: 10.1126/science.abq4654
• 发表日期: 2023-05-26
• 页码: 812-817
• 关键词: carbon sequestration; pacific-ocean; southern-ocean; nitrogen-fixation; DYNAMICS; patterns; database; export; arc

摘要

Iron is an essential nutrient that regulates productivity in similar to 30% of the ocean. Compared with deep (>2000 meter) hydrothermal activity at mid-ocean ridges that provide iron to the ocean's interior, shallow (<500 meter) hydrothermal fluids are likely to influence the surface's ecosystem. However, their effect is unknown. In this work, we show that fluids emitted along the Tonga volcanic arc (South Pacific) have a substantial impact on iron concentrations in the photic layer through vertical diffusion. This enrichment stimulates biological activity, resulting in an extensive patch of chlorophyll (360,000 square kilometers). Diazotroph activity is two to eight times higher and carbon export fluxes are two to three times higher in iron-enriched waters than in adjacent unfertilized waters. Such findings reveal a previously undescribed mechanism of natural iron fertilization in the ocean that fuels regional hotspot sinks for atmospheric CO2.