Background There are a huge number of migratory barriers in the rivers of northern Sweden, primarily consisting of road infrastructure and dams to facilitate the floating of logs by the forestry industry. Inventories show that approximately 30-50% of all culverts are migratory barriers and it is estimated that some 5 000 to 8 000 culverts within valuable watercourses are fish migratory barriers in the counties of Norrbotten and Västerbotten. Some 2 million to 5 million m2 of the watercourses in each area targeted by the LIFE ReMiBar project are negatively affected by road infrastructure and dams. This has a harmful effect upon the freshwater pearl mussel (Margaritifera margaritifera). Badly positioned culverts prevent the Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) reaching suitable spawning habitats and force otters (Lutra lutra) to cross roads rather than go through the culvert, a significant cause of otter mortality (89% of all reported otter deaths in the project area in 2000-2005). Furthermore, artificial barriers are a barrier to achieving the good water quality of surface waters required by the Water Framework Directive (2000/60/EC). Nearly 18 % of water bodies in the Bothnian Bay district are below 'good' status because of artificial barriers. Objectives The overall aim of the project is to minimise migratory barriers in five larger water systems in the northern part of Sweden, where road crossings and dams have been some of the causes of decreasing populations of the targeted species. The conservation status of the Natura 2000 habitats and species will be improved, or maintained, through increased connectivity. The habitats and species targeted by the project are: Fennoscandian natural rivers; Watercourses of plain to montane levels with the Ranunculion fluitans and Callitricho-Batrachion vegetation; freshwater pearl mussel; Atlantic salmon; otter; and bullhead (Cottus gobio). Specific goals are: Remediation of migratory barriers to facilitate the migration of Atlantic salmon and bullhead. This will also benefit the freshwater pearl mussel, as it needs Atlantic salmon and/or brown trout for its reproduction; The physical structures and functions of the two habitats will be restored with methods that strive to achieve a natural condition at the water-road crossing, improving the conservation status of the habitats as a result; Restoration actions to facilitate safe road crossings for otters on public roads; A cost-effective system for knowledge transfer and guidelines for contractors, technicians and landowners that will improve the quality of road-water crossings and restorations in the future; Building an expert network and exchanging best practices, knowledge and ideas between countries in the northern part of Europe (Sweden, Finland and Scotland) regarding facilitating migration of the target species; Constructing easily accessible demonstration areas in strategic locations, representative of the different characters of possible river-road crossings found in different parts of the country. Through these demonstration areas the project will also be disseminated to the public. Expected results: Five water systems to be made significantly more open for fish migration through the conversion of 304 migratory barriers in the project area to functioning passages for the target species; Enabling the atlantic salmon and bullhead to have access to additional areas for spawning, foraging and shelter. This will favour the species and their conservation status; The establishment of new freshwater pearl mussel populations in the river systems as a result of improved fish migration; An increase in the otter survival rate because of safer road crossings (results of otter mitigation will be surveyed and documented in 13 strategic places); Construction of two demonstration sites, in easily accessible areas, for knowledge transfer; and Training and information material (Swedish-English), workshops and study trips.