Revisiting the distribution of oceanic N2 fixation and estimating diazotrophic contribution to marine production.

Published

Journal Article

Marine N2 fixation supports a significant portion of oceanic primary production by making N2 bioavailable to planktonic communities, in the process influencing atmosphere-ocean carbon fluxes and our global climate. However, the geographical distribution and controlling factors of marine N2 fixation remain elusive largely due to sparse observations. Here we present unprecedented high-resolution underway N2 fixation estimates across over 6000 kilometers of the western North Atlantic. Unexpectedly, we find increasing N2 fixation rates from the oligotrophic Sargasso Sea to North America coastal waters, driven primarily by cyanobacterial diazotrophs. N2 fixation is best correlated to phosphorus availability and chlorophyll-a concentration. Globally, intense N2 fixation activity in the coastal oceans is validated by a meta-analysis of published observations and we estimate the annual coastal N2 fixation flux to be 16.7 Tg N. This study broadens the biogeography of N2 fixation, highlights the interplay of regulating factors, and reveals thriving diazotrophic communities in coastal waters with potential significance to the global nitrogen and carbon cycles.

Full Text

Duke Authors

Cited Authors

  • Tang, W; Wang, S; Fonseca-Batista, D; Dehairs, F; Gifford, S; Gonzalez, AG; Gallinari, M; Planquette, H; Sarthou, G; Cassar, N

Published Date

  • February 19, 2019

Published In

Volume / Issue

  • 10 / 1

Start / End Page

  • 831 -

PubMed ID

  • 30783106

Pubmed Central ID

  • 30783106

Electronic International Standard Serial Number (EISSN)

  • 2041-1723

International Standard Serial Number (ISSN)

  • 2041-1723

Digital Object Identifier (DOI)

  • 10.1038/s41467-019-08640-0

Language

  • eng