Spatio-temporal patterns of fish assemblages in a large regulated alluvial river
2009
Rifflart, R. | Carrel, G. | Le Coarer, Y. | Nguyen The Fontez, B. | Hydrobiologie (UR HYAX) ; Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF) | Institut Méditerranéen d'Ecologie et de Paléoécologie (IMEP) ; Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASARE
显示更多 [+] 显示较少 [-]英语. 1. The River Durance, the last alpine tributary of the River Rhone, is a large, braided alluvial hydrosystem. Following large-scale regulation, flow downstream of the Serre-Poncon dam has been maintained at 1⁄40th of previous annual mean discharge. To assess the effects of historical disturbances, fish assemblages and habitat use were analysed during five summers in a representative reach of the middle Durance. 2. Habitat availability and use were assessed with a multi-scale approach including the variables water depth, current velocity, roughness height of substratum, amount of woody debris and lateral⁄longitudinal location. Eighteen fish species were sampled by electrofishing in 289 habitat sample units. 3. Partial least square (PLS) regression showed that taxa were mainly distributed according to relationships between their total length and water depth⁄velocity variables. Fish assemblage composition was also related to roughness height as well as distance from the bank or to the nearest large woody debris. However, PLS regression revealed no significant differences in habitat selection between two periods of varying hydromorphological stability. 4. Fish distribution patterns and density were related to proximity to the bank and cover, indicating that local scale variables need to be considered in conservation and restoration programmes.
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