The Garonne river basin in the Aran Valley (Lleida) has the peculiarity, from the biogeographical point of view, of being a Central European Atlantic basin, which determines the presence of two unique species within the context of the Spanish ichthyofauna. On the one hand, the brown trout belongs to a lineage differentiated from the rest of the Spanish populations and sustains a fishing exploitation with an important socio-economic impact. On the other hand, the cavilat, an endemic species of the Garonne basin that inhabits both Spanish and French territory, and which is listed as “Endangered” is also present.

The strong floods that occurred in 2013 have added new pressure on both species, already affected by various environmental alterations, and it is unknown to what extent they have damaged their populations. This project aims to diagnose the current conservation status of both species, develop and implement management measures to recover their populations, and establish channels for the social dissemination of the values of the fish diversity of this basin.