Hydraulic preferences of shrimps and fishes in tropical insular rivers

Virginie Grandgirard (1) , Dominique Monti (2) , P. Valade (3) , Nicolas Lamouroux (1) , J.P. Mallet (2) , H. Grondin (4)

1 UR MALY - Milieux aquatiques, écologie et pollutions
2 DYNECAR EA 926 - Dynamique des écosystèmes Caraïbe et biologie des espèces associées
3 aucun
4 aucun

Hydraulic habitat models based on the preferences of species for the hydraulic characteristics of their microhabitats are frequently used to evaluate the impact on the habitat of a change in river flow regime. Their application in a tropical insular environment is still limited as little is known about the hydraulic preferences of species. Hydraulic preference models have been developed for 15 taxa (diadromous shrimps and fishes) sampled in 52 rivers in the Caribbean (the French West Indies) and the Indian Ocean (the Reunion island). Five datasets were used and group 8353 samples collected by electrofishing during 320 surveys (reach date) performed between 1999 and 2011. Generalized additive models were used to link variations of taxa density within surveys to the hydraulic characteristics of the microhabitat (velocity, depth and substrate). Hydraulic preferences within each region (Caribbean and Indian Ocean) are significant for most of the taxa and vary little between rivers and surveys. The hydraulic variables explain up to 18.1% (univariate models) and 30.0% (multivariate models) of the deviance of densities within survey. Of the taxa selected, Atya scabra, Macrobrachium heterochirus, Xiphocaris elongata and the Sicydiinae are the most demanding.

Mots clés: MICROHABITAT; HYDRAULIQUE; ZONE TROPICALE; ANTILLES; ILE DE LA REUNION

Domaines: Sciences de l'environnement

Virginie Grandgirard, Dominique Monti, P. Valade, Nicolas Lamouroux, J.P. Mallet, et al.. Hydraulic preferences of shrimps and fishes in tropical insular rivers. River Research and Applications, 2014, 30 (6), p. 766 - p. 779. ⟨10.1002/rra.2675⟩. ⟨hal-01072479⟩