FN Archimer Export Format
PT J
TI In-depth characterization of diazotroph activity across the western tropical South Pacific hotspot of N2 fixation (OUTPACE cruise)
BT 
AF BONNET, Sophie
   CAFFIN, Mathieu
   BERTHELOT, Hugo
   GROSSO, Olivier
   BENAVIDES, Mar
   HELIAS-NUNIGE, Sandra
   GUIEU, Cecile
   STENEGREN, Marcus
   FOSTER, Rachel Ann
AS 1:1,2;2:2;3:2,3;4:2;5:4;6:2;7:5,6;8:7;9:7;
FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;
C1 Aix Marseille Univ, Univ Toulon, CNRS, IRD,MIO UM 110, Noumea 13288, New Caledonia.
   Aix Marseille Univ, Univ Toulon, CNRS, IRD,MIO UM 110, F-13288 Marseille, France.
   Univ Brest, UMR 6539, Lab Sci Environm Marin, CNRS,UBO,IRD,Ifremer,IUEM, Plouzane, France.
   Univ Copenhagen, Dept Biol, Marine Biol Sect, DK-3000 Helsingor, Denmark.
   Sorbonne Univ, UPMC Univ Paris 06, CNRS, LOV, F-06230 Villefranche Sur Mer, France.
   New York Univ Abu Dhabi, Ctr Prototype Climate Modeling, POB 129188, Abu Dhabi, U Arab Emirates.
   Stockholm Univ, Dept Ecol Environm & Plant Sci, S-10690 Stockholm, Sweden.
C2 IRD, FRANCE
   IRD, FRANCE
   UBO, FRANCE
   UNIV COPENHAGEN, DENMARK
   UNIV PARIS 06, FRANCE
   UNIV ABU DHABI, UNITED ARAB EMIRATES
   UNIV STOCKHOLM, SWEDEN
UM LEMAR
IN DOAJ
IF 3.951
TC 38
UR https://archimer.ifremer.fr/doc/00419/53049/53987.pdf
   https://archimer.ifremer.fr/doc/00419/53049/57613.pdf
LA English
DT Article
CR OUTPACE
BO L'Atalante
AB Here we report N2 fixation rates from a  ∼ 4000km transect in the western and central tropical South Pacific, a particularly undersampled region in the world ocean. Water samples were collected in the euphotic layer along a west to east transect from 160°E to 160°W that covered contrasting trophic regimes, from oligotrophy in the Melanesian archipelago (MA) waters to ultra-oligotrophy in the South Pacific Gyre (GY) waters. N2 fixation was detected at all 17 sampled stations with an average depth-integrated rate of 631±286µmol N m−2 d−1 (range 196–1153µmol N m−2 d−1) in MA waters and of 85±79µmol N m−2 d−1 (range 18–172µmol N m−2 d−1) in GY waters. Two cyanobacteria, the larger colonial filamentous Trichodesmium and the smaller UCYN-B, dominated the enumerated diazotroph community ( > 80%) and gene expression of the nifH gene (cDNA > 105 nifH copies L−1) in MA waters. Single-cell isotopic analyses performed by nanoscale secondary ion mass spectrometry (nanoSIMS) at selected stations revealed that Trichodesmium was always the major contributor to N2 fixation in MA waters, accounting for 47.1–83.8% of bulk N2 fixation. The most plausible environmental factors explaining such exceptionally high rates of N2 fixation in MA waters are discussed in detail, emphasizing the role of macro- and micro-nutrient (e.g., iron) availability, seawater temperature and currents. 
PY 2018
PD JUN
SO Biogeosciences
SN 1726-4170
PU Copernicus Gesellschaft Mbh
VL 15
IS 13
UT 000438465800001
BP 4215
EP 4232
DI 10.5194/bg-15-4215-2018
ID 53049
ER

EF