title: Fish habitat selection in a large hydropeaking river: Strong individual and temporal variations revealed by telemetry.
abstract: Modeling individual fish habitat selection in highly variable environments such as hydropeaking rivers is required for guiding efficient management decisions. We analyzed fish microhabitat selection in the heterogeneous hydraulic and thermal conditions (modeled in two-dimensions) of a reach of the large hydropeaking Rhône River locally warmed by the cooling system of a nuclear power plant. We used modern fixed acoustic telemetry techniques to survey 18 fish individuals (five barbels, six catfishes, seven chubs) signaling their position every 3s over a three-month period. Fish habitat selection depended on combinations of current microhabitat hydraulics (e.g. velocity, depth), past microhabitat hydraulics (e.g. dewatering risk or maximum velocities during the past 15days) and to a lesser extent substrate and temperature. Mixed-effects habitat selection models indicated that individual effects were often stronger than specific effects. In the Rhône, fish individuals appear to memorize spatial and temporal environmental changes and to adopt a "least constraining" habitat selection. Avoiding fast-flowing midstream habitats, fish generally live along the banks in areas where the dewatering risk is high. When discharge decreases, however, they select higher velocities but avoid both dewatering areas and very fast-flowing midstream habitats. Although consistent with the available knowledge on static fish habitat selection, our quantitative results demonstrate temporal variations in habitat selection, depending on individual behavior and environmental history. Their generality could be further tested using comparative experiments in different environmental configurations.
authors.affiliation: IRSTEA, UR MALY, Laboratory Dynam, 5 rue de la Doua, - BP 32108, F-69616 Villeurbanne Cedex, France. Electronic address: herve.capra@irstea.fr.
authors.forename: Hervé
authors.initials: H
authors.lastname: Capra
authors.affiliation: IRSTEA, UR MALY, Laboratory Dynam, 5 rue de la Doua, - BP 32108, F-69616 Villeurbanne Cedex, France. Electronic address: laura.plichard@irstea.fr.
authors.forename: Laura
authors.initials: L
authors.lastname: Plichard
authors.affiliation: IRSTEA, UR MALY, Laboratory Dynam, 5 rue de la Doua, - BP 32108, F-69616 Villeurbanne Cedex, France. Electronic address: berge@ecotec.ch.
authors.forename: Julien
authors.initials: J
authors.lastname: Bergé
authors.affiliation: IRSTEA, UR MALY, Laboratory Dynam, 5 rue de la Doua, - BP 32108, F-69616 Villeurbanne Cedex, France. Electronic address: herve.pella@irstea.fr.
authors.forename: Hervé
authors.initials: H
authors.lastname: Pella
authors.affiliation: University of Liège, Applied and Fundamental Fish Research Center (AAFISH), Biology of behaviour Unit, Laboratory of Fish Demography and Hydroecology, 22 Quai Van Beneden, 4020 Liège, Belgium. Electronic address: m.ovidio@ulg.ac.be.
authors.forename: Michaël
authors.initials: M
authors.lastname: Ovidio
authors.affiliation: Hydroquébec, 75 Boulevard René-Lévesque O, Montréal, QC H2Z 1A4, Canada. Electronic address: mcneil.eric@hydro.qc.ca.
authors.forename: Eric
authors.initials: E
authors.lastname: McNeil
authors.affiliation: IRSTEA, UR MALY, Laboratory Dynam, 5 rue de la Doua, - BP 32108, F-69616 Villeurbanne Cedex, France. Electronic address: nicolas.lamouroux@irstea.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Lamouroux
mesh_terms: D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring; D005399:Fishes; D005602:France; D055848:Nuclear Power Plants; D045483:Rivers; D013686:Telemetry; D013696:Temperature; D013997:Time Factors; D014872:Water Movements
keywords: 2D hydrodynamic model; Acoustic telemetry; Fish individual behavior; Habitat preferences; Hydropower impacts