Titre :

Microbial food web dynamics during spring phytoplankton blooms in the naturally iron-fertilized Kerguelen area (Southern Ocean)

Auteur(s) :

Christaki, Urania [Auteur]
Université du Littoral Côte d'Opale [ULCO]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Lefèvre, Dominique [Auteur]
Institut méditerranéen d'océanologie [MIO]
Georges, C. [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Colombet, J. [Auteur]
Laboratoire Microorganismes : Génome et Environnement [LMGE]
Catala, P. [Auteur]
Laboratoire d'Océanographie Microbienne [LOMIC]
Courties, C. [Auteur]
Laboratoire d'Océanographie Microbienne [LOMIC]
Sime-Ngando, T. [Auteur]
Laboratoire Microorganismes : Génome et Environnement [LMGE]
Blain, S. [Auteur]
Laboratoire d'Océanographie Microbienne [LOMIC]
Obernosterer, I. [Auteur]
Laboratoire d'Océanographie Microbienne [LOMIC]

Titre de la revue :

Biogeosciences
KEOPS2: Kerguelen Ocean and Plateau Study 2

Pagination :

6739-6753

Éditeur :

European Geosciences Union

Date de publication :

2014-12-05

ISSN :

1726-4170

Discipline(s) HAL :

Planète et Univers [physics]/Sciences de la Terre/Océanographie
Sciences de l'environnement/Biodiversité et Ecologie
Sciences du Vivant [q-bio]/Microbiologie et Parasitologie

Résumé en anglais : [en]

Microbial food web dynamics were determined during the onset of several spring phytoplankton blooms induced by natural iron fertilization off Kerguelen Island in the Southern Ocean (KEOPS2). The abundances of het-erotrophic ...
Lire la suite >Microbial food web dynamics were determined during the onset of several spring phytoplankton blooms induced by natural iron fertilization off Kerguelen Island in the Southern Ocean (KEOPS2). The abundances of het-erotrophic bacteria and heterotrophic nanoflagellates, bacterial heterotrophic production, bacterial respiration, and bacterial growth efficiency, were consistently higher in surface waters of the iron-fertilized sites than at the reference site in HNLC (high nutrient low chlorophyll) waters. The abundance of virus-like particles remained unchanged, but viral production increased by a factor of 6 in iron-fertilized waters. Bacterial heterotrophic production was significantly related to heterotrophic nanoflagellate abundance and viral production across all sites, with bacterial production explaining about 70 and 85 %, respectively, of the variance of each in the mixed layer (ML). Estimated rates of grazing and viral lysis, however, indicated that heterotrophic nanoflagellates accounted for a substantially higher loss of bacterial production (50 %) than viruses (11 %). Combining these results with rates of primary production and export determined for the study area, a budget for the flow of carbon through the microbial food web and higher trophic levels during the early (KEOPS2) and the late phase (KEOPS1) of the Kerguelen bloom is provided.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Collections :

• Laboratoire d'Océanologie et de Géosciences (LOG) - UMR 8187

Source :

Harvested from HAL