Limnology and Oceanography Letters (Aug 2024)

Global subterranean estuaries modify groundwater nutrient loading to the ocean

  • Stephanie J. Wilson,
  • Amy Moody,
  • Tristan McKenzie,
  • M. Bayani Cardenas,
  • Elco Luijendijk,
  • Audrey H. Sawyer,
  • Alicia Wilson,
  • Holly A. Michael,
  • Bochao Xu,
  • Karen L. Knee,
  • Hyung‐Mi Cho,
  • Yishai Weinstein,
  • Adina Paytan,
  • Nils Moosdorf,
  • Chen‐Tung Aurthur Chen,
  • Melanie Beck,
  • Cody Lopez,
  • Dorina Murgulet,
  • Guebuem Kim,
  • Mathew A. Charette,
  • Hannelore Waska,
  • J. Severino P. Ibánhez,
  • Gwénaëlle Chaillou,
  • Till Oehler,
  • Shin‐ichi Onodera,
  • Mitsuyo Saito,
  • Valenti Rodellas,
  • Natasha Dimova,
  • Daniel Montiel,
  • Henrietta Dulai,
  • Christina Richardson,
  • Jinzhou Du,
  • Eric Petermann,
  • Xiaogang Chen,
  • Kay L. Davis,
  • Sebastien Lamontagne,
  • Ryo Sugimoto,
  • Guizhi Wang,
  • Hailong Li,
  • Américo I. Torres,
  • Cansu Demir,
  • Emily Bristol,
  • Craig T. Connolly,
  • James W. McClelland,
  • Brenno J. Silva,
  • Douglas Tait,
  • BSK Kumar,
  • R. Viswanadham,
  • VVSS Sarma,
  • Emmanoel Silva‐Filho,
  • Alan Shiller,
  • Alanna Lecher,
  • Joseph Tamborski,
  • Henry Bokuniewicz,
  • Carlos Rocha,
  • Anja Reckhardt,
  • Michael Ernst Böttcher,
  • Shan Jiang,
  • Thomas Stieglitz,
  • Houégnon Géraud Vinel Gbewezoun,
  • Céline Charbonnier,
  • Pierre Anschutz,
  • Laura M. Hernández‐Terrones,
  • Suresh Babu,
  • Beata Szymczycha,
  • Mahmood Sadat‐Noori,
  • Felipe Niencheski,
  • Kimberly Null,
  • Craig Tobias,
  • Bongkeun Song,
  • Iris C. Anderson,
  • Isaac R. Santos

DOI
https://doi.org/10.1002/lol2.10390
Journal volume & issue
Vol. 9, no. 4
pp. 411 – 422

Abstract

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Abstract Terrestrial groundwater travels through subterranean estuaries before reaching the sea. Groundwater‐derived nutrients drive coastal water quality, primary production, and eutrophication. We determined how dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and dissolved organic nitrogen (DON) are transformed within subterranean estuaries and estimated submarine groundwater discharge (SGD) nutrient loads compiling > 10,000 groundwater samples from 216 sites worldwide. Nutrients exhibited complex, nonconservative behavior in subterranean estuaries. Fresh groundwater DIN and DIP are usually produced, and DON is consumed during transport. Median total SGD (saline and fresh) fluxes globally were 5.4, 2.6, and 0.18 Tmol yr−1 for DIN, DON, and DIP, respectively. Despite large natural variability, total SGD fluxes likely exceed global riverine nutrient export. Fresh SGD is a small source of new nutrients, but saline SGD is an important source of mostly recycled nutrients. Nutrients exported via SGD via subterranean estuaries are critical to coastal biogeochemistry and a significant nutrient source to the oceans.