@article{fdi:010074909,
  title = {{T}he composition and distribution of semi-labile dissolved organic matter across the southwest {P}acific},
  author = {{P}anagiotopoulos, {C}. and {P}ujo-{P}ay, {M}. and {B}enavides, {M}ar and {V}an {W}ambeke, {F}. and {S}emp{\'e}r{\'e}, {R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he distribution and dynamics of dissolved organic carbon ({DOC}) and dissolved combined neutral sugars ({DCNS}) were studied across an increasing oligotrophic gradient (18 to 22 degrees {S} latitude) in the tropical {S}outh {P}acific {O}cean, spanning from the {M}elanesian {A}rchipelago ({MA}) area to the western part of the {S}outh {P}acific gyre ({WGY}), in austral summer as a part of the {OUTPACE} project. {O}ur results show that {DOC} and {DCNS} concentrations exhibited no statistical differences between the {MA} and {WGY} areas (0-200 m: 47-81 mu {MC} for {DOC} and 0.2-4.2 mu {MC} for {DCNS}). {H}owever, due to a deepening of the euphotic zone, a deeper penetration of {DOC} was noticeable at 150 m of depth at the {WGY} area. {E}xcess {DOC} ({DOCEX}) was determined as the difference between surface and deep-sea {DOC} values, and euphotic zone integrated stocks of both {DOC} and {DOCEX} were higher in the {WGY} than the {MA} area. {C}onsidering {DOCEX} as representative of semi-labile {DOC} ({DOCSL}), its residence time was calculated as the ratio of {DOCSL} to bacterial carbon demand ({BCD}). {T}his residence time was 176 +/- 43 days (n = 3) in the {WGY} area, about 3 times longer than in the {MA} area ({T}-r = 51 +/- 13 days, n = 8), suggesting an accumulation of semi-labile dissolved organic matter ({DOM}) in the surface waters of {WGY}. {A}verage epipelagic (0-200 m) {DCNS} yields ({DCNS} x {DOC}-1) based on volumetric data were roughly similar in both areas, accounting for similar to 2.8 % of {DOC}. {DCNS} exhibited a longer residence time in {WGY} ({T}-r = 91 +/- 41 days, n = 3) than in {MA} ({T}-r = 31 +/- 10 days, n = 8), further suggesting that this {DCNS} pool persists longer in the surface waters of the {WGY}. {T}he accumulation of {DOCEX} in the surface waters of {WGY} is probably due to very slow bacterial degradation due to nutrient and/or energy limitation of heterotrophic prokaryotes, indicating that biologically produced {DOC} can be stored in the euphotic layer of the {S}outh {P}acific gyre for a long period.},
  keywords = {{PACIFIQUE} {SUD} {OUEST}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {16},
  numero = {1},
  pages = {105--116},
  ISSN = {1726-4170},
  year = {2019},
  DOI = {10.5194/bg-16-105-2019},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074909},
}