Global subterranean estuaries modify groundwater nutrient loading to the ocean

WILSON STEHANIE J.; MOODY AMY; MCKENZIE TRISTIAN; CARDENAS BAYANI M.; LUIJENDIJK ELCO; SAWYER AUDREY H.; WILSON ALICIA; MICHAEL HOLLEY A.; XU BOCHAO; KNEE KAREN L.; CHO HYUNG-MI; WEINSTEIN YISHAI; PAYTAN ADINA; MOOSDORF NILS; CHEN CHEN-TUNG A.; BECK MELANIE; CODY LOPEZ; KIM GUEBUEM; CHARETTE MATHEW A.; WASKA HANNELORE; IBÁNHEZ J.S.P.; CHAILLOU GWÉNAËLLE ; OEHLER TILL; ONODERA SHIN-ICHI; RODELLAS VALENTI; SAITO MITSUYO; DIMOVA NATASHA; MONTIEL DANIEL; DULAI HENRIETTA; RICHARDSON CHRISTINA; DU JINZHOU; PETERMANN ERIC; CHEN XIAOGANG; DAVIS KAY L.; LAMONTAGNE SEBASTIEN; SUGIMOTO RYO; WANG GUIZHI; LI HAILONG; TORRES AMÉRICO I.; DEMIR CANSU; BRISTOL EMILY; CONNOLLY CRAIG T.; MCCLELLAND JAMES W.; SILVA BRENNO J.; TAIT DOUGLAS; KUMAR BSK; VISWANADHAM R.; SARMA VVSS; SILVA-FILHO EMMANEOL V.; SHILLER ALAN; LECHER ALANNA; TAMBORSKI JOSEPH; BOKUNIEWICZ HENRY; ROCHA CARLOS; RECKHARDT ANJA; BÖTTCHER MICHAEL E.; JIANG SHAN; STIEGLITZ THOMAS; VINEL GBEWEZOUN HOUÉGNON G.; CHARBONNIER CÉLINE; DANS S.; TERRONES LAURA M.H.; BABU

Limnology and Oceanography Letters

Wiley

Año: 2024

2378-2242

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), phosphorus (DIP), and 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, non-conservative 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.