title: Chemical multi-contamination drives benthic prokaryotic diversity in the anthropized Toulon Bay.
abstract: Investigating the impact of human activities on marine coastal ecosystems remains difficult because of the co-occurrence of numerous natural and human-induced gradients. Our aims were (i) to evaluate the links between the chemical environment as a whole and microbial diversity in the benthic compartment, and (ii) to compare the contributions of anthropogenic and natural chemical gradients to microbial diversity shifts. We studied surface sediments from 54 sampling sites in the semi-enclosed Toulon Bay (NW Mediterranean) exposed to high anthropogenic pressure. Previously published chemical data were completed by new measurements, resulting in an in depth geochemical characterization by 29 representative environmental variables. Bacterial and archaeal diversity was assessed by terminal restriction fragment length polymorphism profiling on a selection of samples distributed along chemical gradients. Multivariate statistical analyses explained from 45% to 80% of the spatial variation in microbial diversity, considering only the chemical variables. A selection of trace metals of anthropogenic origin appeared to be strong structural factors for both bacterial and archaeal communities. Bacterial terminal restriction fragment (T-RF) richness correlated strongly with both anthropogenic and natural chemical gradients, whereas archaeal T-RF richness demonstrated fewer links with chemical variables. No significant decrease in diversity was evidenced in relation to chemical contamination, suggesting a high adaptive potential of benthic microbial communities in Toulon Bay.
authors.affiliation: PROTEE, EA 3819, Université de Toulon, CS 60584, 83041 Toulon Cedex 9, France. Electronic address: misson@univ-tln.fr.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Misson
authors.affiliation: PROTEE, EA 3819, Université de Toulon, CS 60584, 83041 Toulon Cedex 9, France.
authors.forename: Cédric
authors.initials: C
authors.lastname: Garnier
authors.affiliation: Equipe Environnement et Microbiologie, Melody Group, Université de Pau et des Pays de l'Adour, IPREM, UMR CNRS 5254, BP 11055, F-64013 Pau Cedex, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Lauga
authors.affiliation: PROTEE, EA 3819, Université de Toulon, CS 60584, 83041 Toulon Cedex 9, France.
authors.forename: Duc Huy
authors.initials: DH
authors.lastname: Dang
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC) UMR 7621, Observatoire Océanologique, F-66650 Banyuls/mer, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Ghiglione
authors.affiliation: LASEM de Toulon, Base Navale Toulon, BP 61, 83800 Toulon Cedex 9, France.
authors.forename: Jean-Ulrich
authors.initials: JU
authors.lastname: Mullot
authors.affiliation: Equipe Environnement et Microbiologie, Melody Group, Université de Pau et des Pays de l'Adour, IPREM, UMR CNRS 5254, BP 11055, F-64013 Pau Cedex, France.
authors.forename: Robert
authors.initials: R
authors.lastname: Duran
authors.affiliation: MARBEC, UMR 9190, CNRS IRD IFREMER Université Montpellier 2, F-34095 Montpellier, France; Laboratoire de Biosurveillance de l'Environnement, Faculté des Sciences de Bizerte, Zarzouna 7021, Tunisia.
authors.forename: Olivier
authors.initials: O
authors.lastname: Pringault
mesh_terms: D001105:Archaea; D044822:Biodiversity; D004784:Environmental Monitoring; D012623:Seawater / Q000382:microbiology*; D014744:Vietnam; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Marine sediment; Microbial ecotoxicology; Multi-contamination; Prokaryotic diversity