SHIFTS IN THE SUITABLE HABITAT AVAILABLE FOR BROWN TROUT UNDER SHORT-TERM CLIMATE CHANGE SCENARIOS

The impact of climate change in the suitable habitat available for the large brown trout (Salmo trutta L.) was studied in a segment of the Cabriel River (eastern Iberian Peninsula) by coupling a Temez rainfall-runoff model calibrated for the 1960-2000 period (NSE: 0.72), a River-2D hydraulic model and an ensemble of five machine learning techniques (generalized additive models, multilayer perceptron ensembles, fuzzy rule base systems, random forests and support vector machines) describing the habitat suitability for brown trout. The hydrological simulation and habitat assessment were combined to infer the habitat duration curves (HDC) under the Representative Concentration Pathways (RCP 2.6 and 8.5) climate change scenarios. The HDC under future scenarios broadly converged, indicating a marked increment on the frequency of the events of small suitable area, even suggesting a high risk of local extirpation of the brown trout during short time spans.