LAUSR

Abstract Montane biota is vulnerable to climate change, especially in the case of relict species in environmentally extreme areas. The Dades trout Salmo multipunctata is a relict species from the Draa basin, on the southern slopes of the High Atlas Mountains, Morocco. Apart from its genetic and morphological singularity almost nothing is known about this species. We surveyed the whole potential distribution range of the Dades trout and found that only two isolated populations exist (in the Dades and M'Goun catchments), occupying an extremely small range, < 22 km of stream reaches in a narrow altitudinal range (c. 2,150–2,375 m). The species was found more frequently and more abundantly at intermediate elevations within its range, and somatic condition increased with altitude. Climatically suitable areas for the Dades trout will be confined to mountain summits without permanent water bodies by 2070. The Dades trout is a Critically Endangered species in need of active management for its persistence. We propose actions for the long-term conservation of the species, including catchment-scale erosion control, riverbed restoration, local-scale measures to mitigate global warming, and an ex situ breeding programme.