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.

Seasonal changes in fish assemblages in the River Minho tidal freshwater wetlands, NW of the Iberian Peninsula

“…The hydrological annual variability in the River Minho followed other Iberian rivers with a high flow in the autumn/winter period and low flow in the late spring/ summer period (Ferreira et al, 2007). Water temperature followed the same trend, being higher values registered in the summer and lower in the winter.…”

Predicting assemblages and species richness of endemic fish in the upper Yangtze River

“…The structure and processes observed in local fish assemblages are not only determined by local mechanisms acting within assemblages, but also result from processes operating at larger spatial scales (Ferreira et al, 2007). In the present study, altitude, slope, length, discharge, runoff, alpine and sub-alpine meadow and farmland played important roles in driving the observed endemic fish assemblage structure in the upper Yangtze River.…”

Random forests to evaluate biotic interactions in fish distribution models

“…Particularly, studies carried out at the micro-scale showed that both Squalius and Barbus prefer deep-water habitats (Grossman and De Sostoa, 1994;Martínez-Capel et al, 2009). However, contrary to Ferreira et al (2007), the proportion of fine substrate (which is almost absent in the upper Cabriel River) was shown to be an important variable 20 for S. pyrenaicus occurrence. The importance of submerged vegetation for fish has been demonstrated in a number of studies (Arlinghaus and Wolter, 2003;Oliva-Paterna et al, 2003;Santos et al, 2004;Gomes-Ferreira et al, 2005), and has been related to a combination of factors including physical stresses, food availability and predation risk (Ferreira et al, 2007).…”