Background Anadromous (migratory) fish in the lower Ebre River and the Ebre Delta in Catalonia face several conservation challenges, including: insufficient river connectivity; water eutrophication and contamination; low availability of freshwater for the river and delta; inappropriate water temperatures; alien species; fisheries; and chemical pollution. Currently, the conservation status of targeted species in the area is poor. European sturgeon (Acipenser sturio) is no longer present in the lower Ebre and its delta, and other important populations, such as European eel (Anguilla anguilla), twaite shad (Alosa fallax) and sea lamprey (Petromizon marinus), are below their normal capacity levels. The issue of restoring appropriate conditions in Europe’s rivers for migratory fish is addressed by the Water Framework Directive and the European Eel Recovery Plan (Regulation 1100/2007). Several European countries have already tested measures to help restore targeted migratory fish species. Objectives The LIFE MIGRATOEBRE project aims to restore the ecological connectivity of the Ebre River through mitigation measures to improve the river’s hydromorphology. The goal is to improve the long-term conservation of endangered anadromous fish species in the lower Ebre River. It hopes to act as a demonstration project for ecological improvements of other major European rivers. The project plans to adapt all the obstacles in the final stretch of the Ebre River to allow upstream and downstream fish migration. It aims to increase by more than tenfold the river spawning habitat available for European sturgeon, twaite shad and sea lamprey, as well as the distribution and growth area for European eel. It will thus restore the conditions for the natural recovery of healthy and sustainable populations of migratory fish species in the lower Ebre River and Delta within 20-30 years. The project plans to fully engage and involve local communities and a network of nature managers, farmers, fishermen, anglers, water managers, electricity companies, tourism stakeholders, and regional and local authorities. Such engagement will result in the sustainable ecological management and long-term investment in the final stretch of the Ebre River. The project is also intended to initiate steps towards improving the connectivity of the Ebre River with its main tributaries, such as the Segre River and the middle Ebre basin. Expected results: Adaptation of all the obstacles in the lower Ebre – Xerta’s weir, Ascó’s weir, and Flix dam; More than tenfold increase in the available spawning area for European sturgeon, twaite shad and sea lamprey, and the distribution (and growth) area for European eel, making available 64km of new river habitat in four years; More than tenfold increase in the presence of European eel (Anguilla anguilla) in the area upstream of the adapted river obstacles in four years; Presence of twaite shad (Alosa fallax) and sea lamprey (Petromizon marinus) during the spawning period in the area upstream of the adapted river obstacles in four years; Presence of reproductive individuals of the European sturgeon (Acipenser sturio) in the area upstream of the adapted river obstacles within 20-30 years; Creation of a permanent group of volunteers (minimum 10 people) working on improved ecological management in the final stretch of the Ebre River; and More than 10 000 interested stakeholders engaged by the project.