title: Structural and biological trait responses of diatom assemblages to organic chemicals in outdoor flow-through mesocosms.
abstract: The sensitivity of diatom taxonomy and trait-based endpoints to chemicals has been poorly used so far in Environmental Risk Assessment. In this study, diatom assemblages in outdoor flow-through mesocosms were exposed to thiram (35 and 170 μg/L), and a hydrocarbon emulsion (HE; 0.01, 0.4, 2 and 20 mg/L). The effects of exposure were assessed for 12 weeks, including 9 weeks post-treatment, using taxonomic structure and diversity, bioindication indices, biological traits, functional diversity indices, indicator classes and ecological guilds. For both chemicals, diversity increased after the treatment period, and responses of ecological traits were roughly identical with an abundance increase of motile taxa tolerant to organic pollution and decrease of low profile taxa. Bioindication indices were not affected. Traits provided a complementary approach to biomass measurements and taxonomic descriptors, leading to a more comprehensive overview of ecological changes due to organic chemicals, including short- and long-term effects on biofilm structure and functioning.
authors: INRA, UMR985 Écologie et Santé des Écosystèmes, Équipe Écotoxicologie et Qualité des Milieux Aquatiques, Agrocampus Ouest, 65 rue de Saint Brieuc, F-35042 Rennes, France; Service Environnement, TOTAL, Pôle d'Etude et de Recherche de Lacq, RN 117, BP 47, F-64170 Lacq, France. Electronic address: y.bayona@gmail.com.
authors: Yannick
authors: Y
authors: Bayona
authors: INRA, UMR985 Écologie et Santé des Écosystèmes, Équipe Écotoxicologie et Qualité des Milieux Aquatiques, Agrocampus Ouest, 65 rue de Saint Brieuc, F-35042 Rennes, France.
authors: Marc
authors: M
authors: Roucaute
authors: Service Environnement, TOTAL, Pôle d'Etude et de Recherche de Lacq, RN 117, BP 47, F-64170 Lacq, France.
authors: Kevin
authors: K
authors: Cailleaud
authors: INRA, UMR985 Écologie et Santé des Écosystèmes, Équipe Écotoxicologie et Qualité des Milieux Aquatiques, Agrocampus Ouest, 65 rue de Saint Brieuc, F-35042 Rennes, France.
authors: Laurent
authors: L
authors: Lagadic
authors: Service Environnement, TOTAL, Pôle d'Etude et de Recherche de Lacq, RN 117, BP 47, F-64170 Lacq, France.
authors: Anne
authors: A
authors: Bassères
authors: INRA, UMR985 Écologie et Santé des Écosystèmes, Équipe Écotoxicologie et Qualité des Milieux Aquatiques, Agrocampus Ouest, 65 rue de Saint Brieuc, F-35042 Rennes, France.
authors: Thierry
authors: T
authors: Caquet
mesh_terms: D018533:Biomass; D017377:Diatoms / Q000145:classification / Q000502:physiology*; D017753:Ecosystem; D004784:Environmental Monitoring; D009930:Organic Chemicals / Q000032:analysis / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical
keywords: Bioindication indices; Ecological traits; Environmental risk assessment; Fungicide; Petroleum middle distillate