@article{fdi:010072840,
  title = {{D}ynamics and controls of heterotrophic prokaryotic production in the western tropical {S}outh {P}acific {O}cean : links with diazotrophic and photosynthetic activity},
  author = {{V}an {W}ambeke, {F}. and {G}imenez, {A}. and {D}uhamel, {S}. and {D}upouy, {C}{\'e}cile and {L}efevre, {D}. and {P}ujo-{P}ay, {M}. and {M}outin, {T}.},
  editor = {},
  language = {{ENG}},
  abstract = {{H}eterotrophic prokaryotic production ({BP}) was studied in the western tropical {S}outh {P}acific ({WTSP}) using the leucine technique, revealing spatial and temporal variability within the region. {I}ntegrated over the euphotic zone, {BP} ranged from 58 to 120 mg {C} m(-2) d(-1) within the {M}elanesian {A}rchipelago, and from 31 to 50 mg {C} m(-2) d(-1) within the western subtropical gyre. {T}he collapse of a bloom was followed during 6 days in the south of {V}anuatu using a {L}agrangian sampling strategy. {D}uring this period, rapid evolution was observed in the three main parameters influencing the metabolic state: {BP}, primary production ({PP}) and bacterial growth efficiency. {W}ith {N}-2 fixation being one of the most important fluxes fueling new production, we explored relationships between {BP}, {PP} and {N}-2 fixation rates over the {WTSP}. {T}he contribution of {N}-2 fixation rates to bacterial nitrogen demand ranged from 3 to 81 %. {BP} variability was better explained by the variability of {N}-2 fixation rates than by that of {PP} in surface waters of the {M}elanesian {A}rchipelago, which were characterized by {N}-depleted layers and low {DIP} turnover times ({T}-{DIP} < 100 h). {T}his is consistent with the fact that nitrogen was often one of the main factors controlling {BP} on short timescales, as shown using enrichment experiments, followed by dissolved inorganic phosphate ({DIP}) near the surface and labile organic carbon deeper in the euphotic zone. {H}owever, {BP} was more significantly correlated with {PP}, but not with {N}-2 fixation rates where {DIP} was more available ({T}-{DIP} > 100 h), deeper in the {M}elanesian {A}rchipelago, or within the entire euphotic zone in the subtropical gyre. {T}he bacterial carbon demand to gross primary production ratio ranged from 0.75 to 3.1. {T}hese values are discussed in the framework of various assumptions and conversion factors used to estimate this ratio, including the methodological errors, the daily variability of {BP}, the bacterial growth efficiency and one bias so far not considered: the ability for {P}rochlorococcus to assimilate leucine in the dark.},
  keywords = {{PACIFIQUE} {SUD} ; {MELANESIE}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {15},
  numero = {9},
  pages = {2669--2689},
  ISSN = {1726-4170},
  year = {2018},
  DOI = {10.5194/bg-15-2669-2018},
  URL = {https://www.documentation.ird.fr/hor/fdi:010072840},
}