title: Impact of an intense water column mixing (0-1500 m) on prokaryotic diversity and activities during an open-ocean convection event in the NW Mediterranean Sea.
abstract: Open-ocean convection is a fundamental process for thermohaline circulation and biogeochemical cycles that causes spectacular mixing of the water column. Here, we tested how much the depth-stratified prokaryotic communities were influenced by such an event, and also by the following re-stratification. The deep convection event (0-1500 m) that occurred in winter 2010-2011 in the NW Mediterranean Sea resulted in a homogenization of the prokaryotic communities over the entire convective cell, resulting in the predominance of typical surface Bacteria, such as Oceanospirillale and Flavobacteriales. Statistical analysis together with numerical simulation of vertical homogenization evidenced that physical turbulence only was not enough to explain the new distribution of the communities, but acted in synergy with other parameters such as exported particulate and dissolved organic matters. The convection also stimulated prokaryotic abundance (+21%) and heterotrophic production (+43%) over the 0-1500 m convective cell, and resulted in a decline of cell-specific extracellular enzymatic activities (-67%), thus suggesting an intensification of the labile organic matter turnover during the event. The rapid re-stratification of the prokaryotic diversity and activities in the intermediate layer 5 days after the intense mixing indicated a marked resilience of the communities, apart from the residual deep mixed water patch.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.|CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Severin
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.|CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Sauret
authors.affiliation: Aix-Marseille Université, CNRS, Université de Toulon, IRD, MIO UM 110, 13288, Marseille, France.|Université du Sud Toulon-Var, Mediterranean Institute of Oceanography (MIO), 83957, La Garde Cedex, France CNRS-INSU/IRD UM 110.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Boutrif
authors.affiliation: LA, CNRS, Université de Toulouse, 14 avenue Edouard Belin, 31400, Toulouse, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Duhaut
authors.affiliation: LA, CNRS, Université de Toulouse, 14 avenue Edouard Belin, 31400, Toulouse, France.
authors.forename: Fayçal
authors.initials: F
authors.lastname: Kessouri
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.|CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
authors.forename: Louise
authors.initials: L
authors.lastname: Oriol
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.|CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Caparros
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.|CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
authors.forename: Mireille
authors.initials: M
authors.lastname: Pujo-Pay
authors.affiliation: CEFREM, UMR 5110, CNRS-UPVD, F-66860, Perpignan, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Durrieu de Madron
authors.affiliation: Aix-Marseille Université, CNRS, Université de Toulon, IRD, MIO UM 110, 13288, Marseille, France.|Université du Sud Toulon-Var, Mediterranean Institute of Oceanography (MIO), 83957, La Garde Cedex, France CNRS-INSU/IRD UM 110.
authors.forename: Marc
authors.initials: M
authors.lastname: Garel
authors.affiliation: Aix-Marseille Université, CNRS, Université de Toulon, IRD, MIO UM 110, 13288, Marseille, France.|Université du Sud Toulon-Var, Mediterranean Institute of Oceanography (MIO), 83957, La Garde Cedex, France CNRS-INSU/IRD UM 110.
authors.forename: Christian
authors.initials: C
authors.lastname: Tamburini
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.|CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Conan
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.|CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Ghiglione
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D044822:Biodiversity; D052836:Heterotrophic Processes; D008522:Mediterranean Sea; D012621:Seasons; D012623:Seawater / Q000737:chemistry / Q000382:microbiology*