The silica cycle in the modern ocean

Paul J Treguer, University of Western Brittany, Brest, France, Jill Sutton, University of Western Brittany, Institut universitaire d'études marines, Plouzané, France, Stephen B Baines, Stony Brook University, Stony Brook, NY, United States, Mark A Brzezinski, University of California, Marine Science Institute, Santa Barbara, CA, United States, Matthew A Charette, Woods Hole Oceanographic Institution, Marine Chemistry & Geochemistry, Woods Hole, MA, United States, Timothy J DeVries, University of California, Santa Barabara, Earth Research Institute and Department of Geography, Santa Barabara, United States, Stephanie Dutkiewicz, Massachusetts Institute of Technology, Department of Earth, Atmospheric and Planetary Sciences, Cambridge, MA, United States, Claudia Ehlert, Max Planck Institute for Marine Microbiology, Bremen, Germany, Jon Hawkings, University of Bristol, Bristol, BS8, United Kingdom, Aude Leynaert, CNRS, LEMAR IUEM, Plouzané, France, Su Mei Liu, Ocean University of China, Qingdao, China, Natalia Llopis Monferrer, University of Western Brittany, Institut Universitaire Européen de la Mer, Plouzané, France, Manuel Maldonado, Centro de Estudios Avanzados de Blanes, Department of Marine Ecology, Blanes, Spain, Shaily Rahman, University of Florida, Geological Sciences, Ft Walton Beach, FL, United States, Lihua Ran, The second institute of Ocanography, State Oceanic Adiministration, HANGZHOU, China and Olivier Rouxel, IFREMER, Department of Marine Geosciences, Plouzané, France
Abstract:
In the marine world, element Si is unique as it is required for the growth of diatoms and of some sponges, and utilized by radiolarians-rhizarians, silicoflagellates, several species of choanoflagellates, and accumulated by some picocyanobacteria. At the same time, silicifiers have a paramount impact on the marine cycling of silicon and other nutrients (N, P,..) and carbon. So, to better understand the Si cycle in the world ocean is a crucial issue for marine biogeochemistry.The marine silica budget compiled by Tréguer & De La Rocha (2013), which questioned its steady state in the modern ocean, needs revisiting to incorporate recent advances that have notably changed estimates for net Si inputs (submarine groundwater inputs of dissolved silicon, easily dissolvable amorphous silica to the ocean, inputs from the dissolution of terrestrial lithogenic silica in ocean margin sediments, polar inputs from subglacial lakes and melting ice), net Si outputs (reverse weathering removal fluxes, siliceous sponges). Herein, first we show that assuming steady state the Si annual budget can be balanced at 13.1 T mol-Si year-1. Second, from new estimates of biological fluxes we show that other silicifiers than pelagic diatoms might significantly impact the silica cycle at global scale.