title: Use of dispersant in mudflat oil-contaminated sediment: behavior and effects of dispersed oil on micro- and macrobenthos.
abstract: The present study aimed to examine whether the use of dispersant would be suitable for favoring the hydrocarbon degradation in coastal marine sediments without impacting negatively micro- and macrobenthic organisms. Mudflat sediments, maintained during 286 days in mesocosms designed to simulate natural conditions, were contaminated or not with Ural blend crude oil (REBCO) and treated or not with third-generation dispersant (Finasol OSR52). While the dispersant did not lead to an increase of hydrocarbon biodegradation, its use enables an attenuation of more than 55 % of the sediment concentration of total petroleum hydrocarbons (TPH). Canonical correspondence analysis (CCA) correlating T-RFLP patterns with the hydrocarbon content and bacterial abundance indicated weak differences between the different treatments except for the mesocosm treated with oil and dispersant for which a higher bacterial biomass was observed. The use of the dispersant did not significantly decrease the macrobenthic species richness or macroorganisms' densities in uncontaminated or contaminated conditions. However, even if the structure of the macrobenthic communities was not affected, when used in combination with oil, biological sediment reworking coefficient was negatively impacted. Although the use of the dispersant may be worth considering in order to accelerate the attenuation of hydrocarbon-contaminated mudflat sediments, long-term effects on functional aspects of the benthic system such as bioturbation and bacterial activity should be carefully studied before.
authors.affiliation: Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France. philippe.cuny@univ-amu.fr.|Aix-Marseille Université, Bâtiment Méditerranée, Case 901, 13009, Marseille, Cédex 9, France. philippe.cuny@univ-amu.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Cuny
authors.affiliation: INP, UPS; EcoLab (Laboratoire écologie fonctionnelle et environnement), Université de Toulouse, 118 Route de Narbonne, 31062, Toulouse, France.|CNRS, EcoLab, 31062, Toulouse, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Gilbert
authors.affiliation: Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Militon
authors.affiliation: Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Stora
authors.affiliation: Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France.
authors.forename: Patricia
authors.initials: P
authors.lastname: Bonin
authors.affiliation: Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Michotey
authors.affiliation: Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Guasco
authors.affiliation: Centre de Documentation, de Recherche et d'Expérimentations sur les pollutions accidentelles des Eaux, Brest, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Duboscq
authors.affiliation: Equipe Environnement et Microbiologie, MELODY group, Université de Pau et des Pays de l'Adour, IPREM UMR CNRS 5254, BP 1155, 64013, Pau Cedex, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Cagnon
authors.affiliation: Centre de Documentation, de Recherche et d'Expérimentations sur les pollutions accidentelles des Eaux, Brest, France.
authors.forename: Ronan
authors.initials: R
authors.lastname: Jézéquel
authors.affiliation: Equipe Environnement et Microbiologie, MELODY group, Université de Pau et des Pays de l'Adour, IPREM UMR CNRS 5254, BP 1155, 64013, Pau Cedex, France.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Cravo-Laureau
authors.affiliation: Equipe Environnement et Microbiologie, MELODY group, Université de Pau et des Pays de l'Adour, IPREM UMR CNRS 5254, BP 1155, 64013, Pau Cedex, France.
authors.forename: Robert
authors.initials: R
authors.lastname: Duran
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D003902:Detergents / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology; D006838:Hydrocarbons / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D009930:Organic Chemicals / Q000737:chemistry; D010578:Petroleum / Q000378:metabolism; D059392:Petroleum Pollution / Q000032:analysis; D012150:Polymorphism, Restriction Fragment Length; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D003902:Detergents; D006838:Hydrocarbons; D009930:Organic Chemicals; D010578:Petroleum; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; C048322:finasol OSR-5
keywords: Bacteria; Bioremediation; Dispersant; Macrofauna; Mesocosms; Mudflat sediments; Oil pollution