%0 Unpublished work
%T Heterotrophic bacterial production in the South East Pacific: longitudinal trends and coupling with primary production
%+ Laboratoire de MicrobiologiE de Géochimie et d'Ecologie Marines (LMGEM)
%+ Laboratoire d'océanographie biologique de Banyuls (LOBB)
%+ Laboratoire d'océanographie et de biogéochimie (LOB)
%+ Department of Oceanography & Center for Oceanographic Research in the eastern South Pacific
%+ Géoazur (GEOAZUR 6526)
%A van Wambeke, France
%A Obernosterer, I.
%A Moutin, T.
%A Duhamel, S.
%A Ulloa, O.
%A Claustre, Hervé
%Z Revue sans Comité de lecture
%< sans comité de lecture
%@ 1810-6277
%J Biogeosciences Discussions
%I European Geosciences Union
%V 4
%N 4
%P 2761-2791
%8 2008-06-18
%D 2008
%Z Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]
%Z Sciences of the Universe [physics]/Continental interfaces, environment
%Z Sciences of the Universe [physics]/Ocean, Atmosphere
%Z Sciences of the Universe [physics]/Earth SciencesPreprints, Working Papers, ...
%X Spatial variations of heterotrophic bacterial production and phytoplankton primary production were investigated across South East Pacific Ocean (–141° W, –8° S to –72° W, –35° S) in November–December 2004. Bacterial production (³H leucine incorporation) integrated over the euphotic zone encompassed a wide range of values, from 43 mg C m<sup>-2</sup> d<sup>-1</sup> in the hyper-oligotrophic South Pacific Gyre to 392 mg C m<sup>-2</sup> d<sup>-1</sup> in the upwelling off Chile. Within the gyre (120° W, 22° S) records of low phytoplankton biomass (7 mg TChl<i>a</i> m<sup>-2</sup>) were obtained and in situ <sup>14</sup>C based particulate primary production rates were as low as 153 mg C m<sup>-2</sup> d<sup>-1</sup>, thus equal to the value considered as a limit for primary production under strong oligotrophic conditions. In the South Pacific gyre average rates of ³H leucine incorporation rates, and leucine incorporation rates per cell (5–21 pmol L<sup>-1</sup> h<sup>-1</sup> and 15–56×10<sup>-21</sup> mol cell<sup>-1</sup> h<sup>-1</sup>, respectively), were in the same range as those reported for other oligotrophic sub tropical and temperate waters. Rates of dark community respiration, determined at selected stations across the transect varied in a narrow range (42–97 mmol O<sub>2</sub> m<sup>-2</sup> d<sup>-1</sup>), except for one station in the upwelling off Chile (245 mmol O<sub>2</sub> m<sup>-2</sup> d<sup>-1</sup>). Bacterial growth efficiencies varied between 5 and 38% and bacterial carbon demand largely exceeded <sup>14</sup>C particulate primary production across the South Pacific Ocean. Net community production also revealed negative values in the South Pacific Gyre (–13±20 to –37±40 mmol O<sub>2</sub> m<sup>-2</sup> d<sup>-1</sup>). Such imbalances being impossible in this area far from any external input, we discuss the techniques involved for determining the coupling between primary production and bacterial heterotrophic production.
%G English
%2 https://hal.science/hal-00330259/document
%2 https://hal.science/hal-00330259/file/bgd-4-2761-2007.pdf
%L hal-00330259
%U https://hal.science/hal-00330259
%~ IRD
%~ INSU
%~ UNICE
%~ UPMC
%~ CNRS
%~ UNIV-AMU
%~ EGU
%~ EGU-BGD
%~ OCA
%~ GEOAZUR
%~ GIP-BE
%~ LOPB
%~ AGROPOLIS
%~ UNIV-COTEDAZUR
%~ SORBONNE-UNIVERSITE
%~ SU-SCIENCES
%~ SU-SCI
%~ UMS-2348
%~ SU-TI
%~ ALLIANCE-SU