@article{fdi:010073224,
  title = {{I}n-depth characterization of diazotroph activity across the western tropical {S}outh {P}acific hotspot of {N}-2 fixation ({OUTPACE} cruise)},
  author = {{B}onnet, {S}ophie and {C}affin, {M}. and {B}erthelot, {H}. and {G}rosso, {O}. and {B}enavides, {M}ar and {H}elias-{N}unige, {S}. and {G}uieu, {C}. and {S}tenegren, {M}. and {F}oster, {R}. {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{H}ere we report {N}-2 fixation rates from a similar to 4000 km transect in the western and central tropical {S}outh {P}acific, a particularly undersampled region in the world ocean. {W}ater samples were collected in the euphotic layer along a west to east transect from 160 degrees {E} to 160 degrees {W} that covered contrasting trophic regimes, from oligotrophy in the {M}elanesian archipelago ({MA}) waters to ultraoligotrophy in the {S}outh {P}acific {G}yre ({GY}) waters. {N}-2 fixation was detected at all 17 sampled stations with an average depth-integrated rate of 631 +/- 286 mu mol {N}m(-2) d(-1) (range 196-1153 mu mol {N}m(-2) d(-1)) in {MA} waters and of 85 +/- 79 mu mol {N}m(-2) d(-1) (range 18-172 mu mol {N}m(-2) d(-1)) in {GY} waters. {T}wo cyanobacteria, the larger colonial filamentous {T}richodesmium and the smaller {UCYN}-{B}, dominated the enumerated diazotroph community (>80 %) and gene expression of the nif{H} gene (c{DNA} > 10(5) nif{H} copies {L}-1) in {MA} waters. {S}ingle-cell isotopic analyses performed by nanoscale secondary ion mass spectrometry (nano{SIMS}) at selected stations revealed that {T}richodesmium was always the major contributor to {N}-2 fixation in {MA} waters, accounting for 47.1-83.8% of bulk {N}-2 fixation. {T}he most plausible environmental factors explaining such exceptionally high rates of {N}-2 fixation in {MA} waters are discussed in detail, emphasizing the role of macro- and micro-nutrient (e.g., iron) availability, seawater temperature and currents.},
  keywords = {{PACIFIQUE} ; {MELANESIE} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {15},
  numero = {13},
  pages = {4215--4232},
  ISSN = {1726-4170},
  year = {2018},
  DOI = {10.5194/bg-15-4215-2018},
  URL = {https://www.documentation.ird.fr/hor/fdi:010073224},
}