title: The contribution of a niche-based approach to ecological risk assessment: using macroinvertebrate species under multiple stressors.
abstract: We propose that a niche-based experimental approach at population level could be used to solve some uncertainties in traditional approaches in ecotoxicology. We tested this approach in the context of multiple stressors (i.e. chemical and physical) in a selection of six run-of-river reservoirs with different levels of sediment contamination and associated upstream and downstream river sites. A niche-based approach was tested using three functional traits (habitat, food preferences and body size) and discrepancy between the realized and theoretical niches. We first identified three groups of taxa and then recorded differences along the disturbance gradients, such as an increase in competition, a narrowing of spatial and trophic niche breadth (e.g. of Leuctra major and Gammarus pulex), a widening of spatial niche breadth (e.g. of Ephemerella ignita), a greater proportion of small individuals (e.g. of G. pulex) and a decreasing or an increasing (e.g. L. major) discrepancy between realized and theoretical niches.
authors.affiliation: Université de Lorraine, CNRS UMR 7360, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), rue du Général Délestraint, 57070 Metz, France; Université de Toulouse, INP, UPS, EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement), 118 Route de Narbonne, 31062 Toulouse, France; CNRS, EcoLab, 31062 Toulouse, France. Electronic address: fanny.colas@univ-tlse3.fr.
authors.forename: Fanny
authors.initials: F
authors.lastname: Colas
authors.affiliation: Université de Lorraine, CNRS UMR 7360, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), rue du Général Délestraint, 57070 Metz, France. Electronic address: amandine.vigneron@irstea.fr.
authors.forename: Amandine
authors.initials: A
authors.lastname: Vigneron
authors.affiliation: Université de Lorraine, CNRS UMR 7360, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), rue du Général Délestraint, 57070 Metz, France. Electronic address: vincent.felten@univ-lorraine.fr.
authors.forename: Vincent
authors.initials: V
authors.lastname: Felten
authors.affiliation: Université de Lorraine, CNRS UMR 7360, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), rue du Général Délestraint, 57070 Metz, France. Electronic address: simon.devin@univ-lorraine.fr.
authors.forename: Simon
authors.initials: S
authors.lastname: Devin
mesh_terms: D033304:Amphipoda / Q000502:physiology*; D000818:Animals; D004463:Ecology; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D018570:Risk Assessment; D045483:Rivers; D013312:Stress, Physiological; D014876:Water Pollution / Q000032:analysis
keywords: Dam presence; Realized niche; Risk assessment; Sediment contamination; Theoretical niche