Biodiversity and Conservation

, Volume 20, Issue 1, pp 41–57

Reservoirs promote the taxonomic homogenization of fish communities within river basins

Original Paper

DOI: 10.1007/s10531-010-9945-3

Cite this article as:
Clavero, M. & Hermoso, V. Biodivers Conserv (2011) 20: 41. doi:10.1007/s10531-010-9945-3


Most studies analyzing patterns in biotic homogenization of fish communities have used large-scale approaches, while the community-level effects of species introductions and local extinctions within river basins have been sparsely analyzed. In this article, we examine patterns in freshwater fish α- and β-diversity in relation to the presence of reservoirs in a Mediterranean river (Guadiana river; Iberian Peninsula). We used fish samples from 182 river localities and 59 reservoir ones to address two main questions: (i) do reservoirs favor the establishment of invasive fish species?; and (ii) do reservoirs bear taxonomically homogenized fish communities? Although total species richness was not different between rivers and reservoirs, the latter had more invasive species and less native ones. Fish species found in reservoirs tended to be larger ones, but invasive species of any size showed higher preferences for reservoirs. Native species that were rare or absent in reservoirs were those that showed higher sensitivity to invasive species in rivers. Reservoir fish communities were taxonomically homogenized in relation to river ones, both when considering all fish species and using only natives or only invasive ones. Our results suggest that invasive species occupying reservoirs constitute an ecological filter excluding most native species from such systems. Invasive species in the study area are often widely introduced elsewhere, while native species found in reservoirs are congeneric and ecologically similar to those found in other Iberian studies. Thus, we conclude that reservoirs promote taxonomic homogenization at multiple spatial scales, while could also be promoting the functional homogenization of Iberian fish communities.


Biotic homogenizationβ-diversityFreshwater fishFish conservationMediterranean riversInvasive speciesRegulated rivers

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  1. 1.Grup d’Ecologia del Paisatge, Àrea de Biodiversitat, Centre Tecnològic Forestal de CatalunyaSolsonaSpain
  2. 2.Departament de Ciències AmbientalsUniversitat de GironaGironaSpain
  3. 3.Departamento de Biología Ambiental y Salud PúblicaUniversidad de HuelvaHuelvaSpain
  4. 4.The Ecology Centre, School of Biological SciencesUniversity of QueenslandSt LuciaAustralia