Regional and local environmental correlates of native Iberian fish fauna

Abstract

Knowledge of fishes’ habitat requirements is an essential tool for species conservation. We examined the habitat requirements of nine native freshwater fish species using 165 undisturbed or minimally disturbed sites from eight river basins in western Iberia (northern and central Portugal). Six environmental descriptors were considered at the regional level, and six descriptors at a local scale. Statistical associations between local assemblage structure and environmental variables were quantified by canonical correspondence analyses. Logistic regression was performed for each species to identify regional and local factors related to its distribution at the sample sites. The results suggested a reasonable degree of specialisation in the use of local variables and dependence on regional variables. Logistic regression models showed a good adjustment (0.75 < AUC < 0.93). Results of habitat modelling using minimally disturbed sites helped to clarify species preferences for specific abiotic drivers.