Bonnet Sophie auteur aut IRD Rodier Martine auteur aut IRD Turk-Kubo K. A. auteur aut IRD Germineaud C. auteur aut IRD Menkès Christophe auteur aut IRD Ganachaud Alexandre auteur aut IRD Cravatte Sophie auteur aut IRD Raimbault P. auteur aut IRD Campbell E. auteur aut IRD Queroue F. auteur aut IRD Sarthou G. auteur aut IRD Desnues Anne auteur aut IRD Maes Christophe auteur aut IRD Eldin Gérard auteur aut IRD text journalArticle eng text/pdf born digital access Biological dinitrogen (N-2) fixation and the distribution of diazotrophic phylotypes were investigated during two cruises in the Coral Sea and the Solomon Sea (southwestern Pacific) during austral winter conditions. N-2 fixation rates were measurable at every station, but integrated (0-150 m) rates were an order of magnitude higher in the Solomon Sea (30 to 5449 mu mol N m(-2) d(-1)) compared to those measured in the Coral Sea (2 to 10(9) mu mol N m(-2) d(-1)). Rates measured in the Solomon Sea were in the upper range (100-1000 mu mol N m(-2) d(-1)) or higher than rates compiled in the global MARine Ecosystem biomass DATa database, indicating that this region has some of the highest N-2 fixation rates reported in the global ocean. While unicellular diazotrophic cyanobacteria from group A (UCYN-A1 and UCYN-A2) and the proteobacteria gamma-24774A11 dominated in the Coral Sea and were correlated with N-2 fixation rates (p < 0.05), Trichodesmium and UCYN-B dominated in the Solomon Sea and were correlated (p < 0.05) with N-2 fixation rates. UCYN-A were totally absent in the Solomon Sea. The biogeographical distribution of diazotrophs is discussed within the context of patterns in measured environmental parameters. specialized PACIFIQUE SALOMON MER CORAIL MER 032 036 29 11 1874-1892 2015 0886-6236 https://www.documentation.ird.fr/hor/fdi:010066151 10.1002/2015gb005117 0886-6236 [F B010066151] https://www.documentation.ird.fr/hor/fdi:010066151 https://www.documentation.ird.fr/intranet/publi/2016/02/010066151.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2016-02-26 2017-08-23 fdi:010066151 fre