Year: 2025
Type: article
Abstract: The Great Atlantic Sargassum Belt first appeared in 2011 and quickly became the largest interconnected floating biome on Earth. In recent years, Sargassum stranding events have caused substantial ecological and socio-economic impacts in coastal communities. Sargassum requires both phosphorus (P) and nitrogen (N) for growth, yet the primary sources of these nutrients fuelling the extensive Sargassum blooms remain unclear. Here we use coral-bound N isotopes to reconstruct N 2 fixation, the ultimate source of the ocean’s bioavailable N, across the Caribbean over the past 120 years. Our data indicate that changes in N 2 fixation were primarily controlled by multidecadal and interannual changes in equatorial Atlantic upwelling of ‘excess P’, that is, P in stoichiometric excess relative to fixed N. We show that the supply of excess P from equatorial upwelling and N from the N 2 fixation response can account for the majority of Sargassum variability since 2011. Sargassum dynamics are best explained by their symbiosis with N 2 -fixing epiphytes, which render the macroalgae highly competitive during strong equatorial upwelling of excess P. Thus, the future of Sargassum in the tropical Atlantic will depend on how global warming affects equatorial Atlantic upwelling and the climatic modes that control it.
Source: Nature Geoscience
Authors: Jonathan Jung, Nicolas N. Duprey, Alan D. Foreman, Juan Pablo D’Olivo, Carolin Pellio, Yeongjun Ryu, Erin L. Murphy, Baseerat Romshoo, Diego K. Kersting, Gabriel O. Cardoso, Tanja Wald, François Fripiat, Carlos Jimenez, Eberhard Gischler, Paolo Montagna, Carlos Alonso-Hernández, Miguel Gomez-Batista, Christina Treinen-Crespo, José Carriquiry, Maria Rosabelle Ong, Nathalie F. Goodkin, Reia Guppy, Hedy Aardema, Hans Slagter, Lena Heins, Isabella Hrabe de Angelis, Aaron L. Bieler, Maayan Yehudai, Trevor P. Noël, Kendon James, Denis Scholz, Chuanmin Hu, Brian B. Barnes, Andrea Pozzer, Christopher Pöhlker, Jos Lelieveld, Ulrich Pöschl, Hubert Vonhof, Gerald H. Haug, Ralf Schiebel, Daniel M. Sigman, Alfredo Martínez-García
Institutions: Max Planck Institute for Chemistry, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Princeton University, Ocean Conservancy, Arizona State University, Consejo Superior de Investigaciones Científicas, Instituto de Acuicultura Torre de la Sal, Freie Universität Berlin, Université Libre de Bruxelles, Goethe University Frankfurt, National Research Council, Istituto di Scienze Polari, International Atomic Energy Agency, University of Cienfuegos, Universidad Autónoma de Baja California, American Museum of Natural History, Lamont-Doherty Earth Observatory, Columbia University, University of Trinidad and Tobago, ETH Zurich, St. George's University, Windward Islands Research and Education Foundation, Johannes Gutenberg University Mainz, University of South Florida St. Petersburg, Cyprus Institute
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $12,690
Funders: National Science Foundation, National Aeronautics and Space Administration, Princeton University, Arizona State University, Deutsche Forschungsgemeinschaft, Fonds De La Recherche Scientifique - FNRS, Nuclear Safety and Security Commission, Johannes Gutenberg-Universität Mainz, Max-Planck-Gesellschaft, Vrije Universiteit Brussel, Universidad de Costa Rica, Goethe-Universität Frankfurt am Main
Awards: G2976167125, Collaborative Research: Multi-century hydrologic and NAO variability in the tropical Western Atlantic - A Marine NAO Synthesis, G623407248, SPP 2299: Tropische Klimavariabilität und Korallenriffe.
Von der Vergangenheit in die Zukunft Ein Blick auf aktuelle Änderungsraten in ultrahoher Auflösung, Der marine Stickstoffkreislauf in einer sich erwärmenden Welt: Anhaltspunkte aus der Vergangenheit, Lehren für das Anthropozän (NITROCENE), G7651812522
OpenAlex ID: W4415913435