title: Consequences of contaminant mixture on the dynamics and functional diversity of bacterioplankton in a southwestern Mediterranean coastal ecosystem.
abstract: Contamination of coastal environments is often due to a complex mixture of pollutants, sometimes in trace levels, that may have significant effects on diversity and function of organisms. The aim of this study was to evaluate the short-term dynamics of bacterioplankton exposed to natural and artificial mixtures of contaminants. Bacterial communities from a southwestern Mediterranean ecosystem, lagoon and the bay (offshore) of Bizerte were exposed to i) elutriate from resuspension of contaminated sediment, and ii) an artificial mixture of metals and herbicides mimicking the contamination observed during sediment resuspension. Elutriate incubation as well as artificial spiking induced strong enrichments in nutrients (up to 18 times), metals (up to six times) and herbicides (up to 20 times) relative to the in situ concentrations in the offshore station, whereas the increases in contaminants were less marked in the lagoon station. In the offshore waters, the artificial mixture of pollutants provoked a strong inhibition of bacterial abundance, production and respiration and significant modifications of the potential functional diversity of bacterioplankton with a strong decrease of the carbohydrate utilization. In contrast, incubation with elutriate resulted in a stimulation of bacterial activities and abundances, suggesting that the toxic effects of pollutants were modified by the increase in nutrient and DOM concentrations due to the sediment resuspension. The effects of elutriate and the artificial mixture of pollutants on bacterial dynamics and the functional diversity were less marked in the lagoon waters, than in offshore waters, suggesting a relative tolerance of lagoon bacteria against contaminants.
authors.affiliation: UMR 9190 MARBEC IRD-Ifremer-CNRS-Université de Montpellier, Place Eugène Bataillon, Case 093, 34095 Montpellier Cedex 5, France; Faculté des Sciences de Bizerte, Université de Carthage, 7021 Zarzouna, Tunisia. Electronic address: olivier.pringault@ird.fr.
authors.forename: Olivier
authors.initials: O
authors.lastname: Pringault
authors.affiliation: UMR 9190 MARBEC IRD-Ifremer-CNRS-Université de Montpellier, Place Eugène Bataillon, Case 093, 34095 Montpellier Cedex 5, France; Faculté des Sciences de Bizerte, Université de Carthage, 7021 Zarzouna, Tunisia.
authors.forename: Céline
authors.initials: C
authors.lastname: Lafabrie
authors.affiliation: Ecole des Mines d'Alès, LGEI, 6 Avenue de Clavières, 30319 Alès Cedex, France.
authors.forename: Murielle
authors.initials: M
authors.lastname: Avezac
authors.affiliation: UMR 5569 HYDROSCIENCES IRD-CNRS-Université de Montpellier, 163 rue Auguste Broussonnet, 34090 Montpellier, France.
authors.forename: Chrystelle
authors.initials: C
authors.lastname: Bancon-Montigny
authors.affiliation: UMR 9190 MARBEC IRD-Ifremer-CNRS-Université de Montpellier, Place Eugène Bataillon, Case 093, 34095 Montpellier Cedex 5, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Carre
authors.affiliation: Institut Supérieur de Pêche et d'Aquaculture de Bizerte, 7021 Zarzouna, Tunisia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Chalghaf
authors.affiliation: UMR 5569 HYDROSCIENCES IRD-CNRS-Université de Montpellier, 163 rue Auguste Broussonnet, 34090 Montpellier, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Delpoux
authors.affiliation: UMR 5569 HYDROSCIENCES IRD-CNRS-Université de Montpellier, 163 rue Auguste Broussonnet, 34090 Montpellier, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Duvivier
authors.affiliation: UMR 5569 HYDROSCIENCES IRD-CNRS-Université de Montpellier, 163 rue Auguste Broussonnet, 34090 Montpellier, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Elbaz-Poulichet
authors.affiliation: Ecole des Mines d'Alès, LGEI, 6 Avenue de Clavières, 30319 Alès Cedex, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Gonzalez
authors.affiliation: UMR 9190 MARBEC IRD-Ifremer-CNRS-Université de Montpellier, Place Eugène Bataillon, Case 093, 34095 Montpellier Cedex 5, France.
authors.forename: Patrice
authors.initials: P
authors.lastname: Got
authors.affiliation: UMR 9190 MARBEC IRD-Ifremer-CNRS-Université de Montpellier, Place Eugène Bataillon, Case 093, 34095 Montpellier Cedex 5, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Leboulanger
authors.affiliation: Ecole des Mines d'Alès, LGEI, 6 Avenue de Clavières, 30319 Alès Cedex, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Spinelli
authors.affiliation: Faculté des Sciences de Bizerte, Université de Carthage, 7021 Zarzouna, Tunisia.
authors.forename: Asma Sakka
authors.initials: AS
authors.lastname: Hlaili
authors.affiliation: UMR 9190 MARBEC IRD-Ifremer-CNRS-Université de Montpellier, Place Eugène Bataillon, Case 093, 34095 Montpellier Cedex 5, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Bouvy
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D044822:Biodiversity; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D007700:Kinetics; D008522:Mediterranean Sea; D010933:Plankton / Q000187:drug effects* / Q000254:growth & development; D012623:Seawater / Q000737:chemistry / Q000382:microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Bacterial growth efficiency; Bacterial production; Community level physiological profiles; Herbicides; Metals; Microcosms