FN Archimer Export Format
PT J
TI Prokaryotic diversity and activity in contrasting productivity regimes in late summer in the Kerguelen region (Southern Ocean)
BT 
AF Hernandez-Magana, Alejandra Elisa
   Liu, Yan
   Debeljak, Pavla
   Crispi, Olivier
   Marie, Barbara
   Koedooder, Coco
   Obernosterer, Ingrid
AS 1:1,2;2:1,3;3:1,4;4:1;5:1;6:1;7:1;
FF 1:;2:;3:;4:;5:;6:;7:;
C1 Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne, LOMIC, F-66650 Banyuls/mer, France
   Nordcee, Department of Biology, University of Southern Denmark, Odense M, Denmark
   School of Life Sciences, Ludong University, Yantai, China
   University of Vienna, Department of Functional and Evolutionary Ecology, A-1090 Vienna, Austria
C2 UNIV SORBONNE, FRANCE
   UNIV SOUTHERN DENMARK, DENMARK
   UNIV LUDONG, CHINA
   UNIV VIENNA, AUSTRIA
IF 3.01
TC 6
UR https://archimer.ifremer.fr/doc/00694/80583/83802.pdf
LA English
DT Article
CR MOBYDICK-THEMISTO
BO Marion Dufresne
DE ;Prokaryotic community composition;16S rRNA;Amplicon sequence variants;Natural iron fertilization;Southern Ocean
AB Natural iron (Fe) fertilization sustains phytoplankton blooms above the Kerguelen plateau (Indian sector of the Southern Ocean) within otherwise low productive off-plateau waters. In early spring and summer, these diatom-dominated blooms are associated with distinct heterotrophic prokaryotic communities, but whether a structuring effect extends to the post-bloom period has thus far not been investigated. To address this question, we carried out a detailed study of the prokaryotic community composition in the region of Kerguelen Island during late Austral summer (18 February to 27 March 2018; MOBYDICK project). Concentrations of chlorophyll a were seasonally low above the plateau (0.27–0.58 μg Chl a L−1) and in a similar range to those at the 3 off-plateau sites investigated (0.14–0.34 μg Chl a L−1), but we observed an accumulation of dissolved organic carbon and the build-up of heterotrophic prokaryotic biomass in Kerguelen plateau waters. Illumina sequencing of the 16S rRNA gene revealed that the total (DNA-based) and potentially active (RNA-based) prokaryotic communities were structured according to on- and off-plateau sites in the wind-mixed surface layer, in both the free-living (<0.8 μm size fraction) and particle-attached (>0.8 μm size fraction) size fractions. The Amplicon Sequence Variants (ASV) with significantly higher relative abundances in on-plateau surface waters as compared to off-plateau waters belonged to Halieaceae OM60 group, several Flavobacteriaceae, such as the NS5 marine group, Aurantivirga and Ulvibacter, Rhodobacteraceae Loktanella, Saprospiraceae, and the Cryomorphaceae NS10 marine group. ASVs with higher relative abundances in off-plateau waters belonged to the Flavobacteriaceae Formosa, the Rhodobacteraceae Planktomarina and the SAR11 clade. We discuss the potential abiotic and biotic drivers of community composition in late Austral summer and the ecological roles of abundant prokaryotic taxa in Kerguelen plateau waters. 
PY 2021
PD SEP
SO Journal Of Marine Systems
SN 0924-7963
PU Elsevier BV
VL 221
UT 000658513500002
DI 10.1016/j.jmarsys.2021.103561
ID 80583
ER

EF