Natural 15 N 15 N abundances constrain fixed nitrogen loss
Nitrogen regulates primary productivity across much of the biosphere, yet fixed nitrogen loss remains poorly constrained because existing methods rely on indirect proxies or ex situ experiments. In this study, we show that natural abundances of the rare 15 N 15 N isotopologue of dinitrogen (N 2 ) provide a direct tracer of biological N 2 production across diverse aquatic environments. N 2 produced by denitrification and anammox has a near-stochastic 15 N 15 N distribution [0 per mil (‰)], whereas atmospheric N 2 carries a distinct 15 N 15 N excess (19‰), allowing the two sources to be quantitatively distinguished. Across aquifers, stratified lakes, coastal basins, oxygen minimum zones, and marine sediments, 15 N 15 N measurements reveal widespread nitrogen loss previously obscured by physical gas accumulation and nitrogen fixation. Natural 15 N 15 N abundances therefore provide a general framework for directly constraining fixed nitrogen loss across the aquatic nitrogen cycle.
Authors
- Dale T. Andersen (ORCID: https://orcid.org/0000-0001-8827-1259)
- Claudia Frey (ORCID: https://orcid.org/0000-0002-3544-3800)
- Daniele Bianchi (ORCID: https://orcid.org/0000-0002-6621-0858)
- André Pellerin (ORCID: https://orcid.org/0000-0003-3588-8372)
- Elen Reji
- Elizabeth D. Swanner (ORCID: https://orcid.org/0000-0001-9507-0893)
- James Mullahoo (ORCID: https://orcid.org/0000-0002-5469-4066)
- M. Bayani Cardenas (ORCID: https://orcid.org/0000-0001-6270-3105)
- Edward Young (ORCID: https://orcid.org/0000-0002-1299-0801)
- David L. Valentine (ORCID: https://orcid.org/0000-0001-5914-9107)
- Denis Lacelle (ORCID: https://orcid.org/0000-0002-6691-8717)
- Kelsey M. Gosselin (ORCID: https://orcid.org/0000-0002-9327-8954)
- Moritz F. Lehmann (ORCID: https://orcid.org/0000-0003-0626-5942)
- Katelyn McPaul (ORCID: https://orcid.org/0000-0001-9941-2969)
- Aoshuang Ji (ORCID: https://orcid.org/0000-0002-9152-1287)
- Annie Bourbonnais (ORCID: https://orcid.org/0000-0001-7247-5230)
- Victoria J. Orphan (ORCID: https://orcid.org/0000-0002-5374-6178)
- Alan Seltzer (ORCID: https://orcid.org/0000-0003-2870-1215)
- Tina Treude (ORCID: https://orcid.org/0000-0001-6366-286X)
- Jiarui Liu (ORCID: https://orcid.org/0000-0003-4878-6578)
- Franklin S. Kinnaman
- Grace A. Brown (ORCID: https://orcid.org/0000-0002-9934-385X)
- Daniel Fillion
Institutions
- University College Dublin (IE)
- University of California, Riverside (US)
- California Institute of Technology (US)
- University of Ottawa (CA)
- University of California, Santa Barbara (US)
- University of South Carolina (US)
- University of California, Los Angeles (US)
- Iowa State University (US)
- Université du Québec à Rimouski (CA)
- University of Basel (CH)
- Institut des sciences de la mer
- Massachusetts Institute of Technology (US)
- Woods Hole Oceanographic Institution (US)
- The University of Texas at Austin (US)
- Search for Extraterrestrial Intelligence (US)
Publication Details
- Journal
- Science
- Published
- 2026-10-08
- DOI
- https://doi.org/10.1126/science.aei0940
- Primary Topic
- Marine and coastal ecosystems
- Type
- article
- Field-Weighted Citation Impact
- 0.00