Distribution and rates of nitrogen fixation in the western tropical South Pacific Ocean constrained by nitrogen isotope budgets

Knapp, Angela N.; McCabe, Kelly M.; Grosso, Olivier; Leblond, Nathalie; Moutin, Thierry; Bonnet, Sophie

doi:https://doi.org/10.5194/bg-15-2619-2018

Articles | Volume 15, issue 9

https://doi.org/10.5194/bg-15-2619-2018

© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue:

Interactions between planktonic organisms and biogeochemical...

https://doi.org/10.5194/bg-15-2619-2018

© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 15, issue 9

Research article

|

04 May 2018

Research article |

| 04 May 2018

Distribution and rates of nitrogen fixation in the western tropical South Pacific Ocean constrained by nitrogen isotope budgets

Angela N. Knapp, Kelly M. McCabe, Olivier Grosso, Nathalie Leblond, Thierry Moutin, and Sophie Bonnet

Data sets

Water column nitrate+nitrite d15N measurements from R/V L'Atalante in the southwest Pacific Ocean between New Caledonia and Tahiti from February to March 2015 Knapp, A., McCabe, K., Grosso, O., Leblond, N., Moutin, T., Bonnet, S. https://doi.org/10.1575/1912/bco-dmo.733303

Short summary

The spatial distribution of biological N₂ fixation fluxes to the ocean remains poorly constrained. Here we use nitrogen isotope budgets to identify significant N₂ fixation inputs to the western tropical South Pacific (WTSP), where N₂ fixation supports > 50 % of export production at stations proximal to iron sources. The significant N₂ fixation inputs in the WTSP may offset nitrogen loss in the oxygen-deficient zones of the eastern tropical South Pacific.