PROJECT DESCRIPTION
BACKGROUND
There are a huge number of migratory barriers in the rivers of northern Sweden, primarily consisting of road infrastructure and dams built 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 2-5 million m2 of the watercourses in each project area are negatively affected by migratory barriers, with harmful impacts on for example the freshwater pearl mussel (Margaritifera margaritifera). Badly-positioned culverts prevent Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) reaching suitable spawning habitats, and force otter (Lutra lutra) to cross roads rather than go through the culvert, a significant cause of mortality (89% of all reported otter deaths in project areas in 2000-2005). Furthermore, artificial barriers present a major hurdle to achieving the surface waters quality required by the Water Framework Directive (2000/60/EC). For instance, nearly 27% of water bodies in the Bothnian Bay district are below 'good' status because of artificial barriers.
OBJECTIVES
The objective of the ReMiBar project was to reduce migratory barriers in five larger water drainage systems in northern Sweden, where road crossings and dams are among the causes of decreasing populations of the targeted species. The project aimed to improve or maintain the conservation status of two Natura 2000 network habitat types and four target species in those habitats, by increasing connectivity.
Specific project goals included removal or modification of barriers to facilitate migration of Atlantic salmon and bullhead, which also benefits the freshwater pearl mussel that needs Atlantic salmon and/or brown trout for its reproduction. The project also aimed to restore physical structures and functions of the two habitats to achieve near-natural conditions; facilitate safe road crossings for otters on public roads; build an expert network and exchange best practices and knowledge between countries in northern Europe; and construct easily-accessible demonstration areas in strategic locations to raise public awareness and facilitate replication of the methods.
RESULTS
The ReMiBar project successfully removed 304 migratory barriers from watercourses in Norrbotten and Västerbotten counties in northern Sweden. In total, the project team remediated and reconnected 1 700 km of streams, with a total surface area of 67 km2. This contributed to improved habitat connectivity in five large river catchment areas, and to improving the quality and conservation status of target habitats and species in five Natura 2000 network sites.
Restoration actions improved the conservation status of the target habitats ‘Fennoscandian natural rivers’ and ‘Watercourses of plain to montane levels with the Ranunculion fluitans and Callitricho-Batrachion vegetation’, and of the following species: freshwater pearl mussel, Atlantic salmon, otter, and bullhead (Cottus gobio). Monitoring indicated that the measures conducted by the ReMiBar project resulted in improved migration conditions for all riverine species, due to the opening up of five large river catchment areas.
The majority of the structures that constituted migration barriers for fish and other aquatic organisms consisted of culverts that were often too narrow and too steep to allow passage for migration. The project replaced most of the culverts with arches, but some with bridges or wider culverts. A total of 42 dams were removed, and the original or existing water level was maintained through the construction of a rocky ramp. The project constructed otter passages at 11 bridges where otters could not previously pass safely underneath.
ReMiBar beneficiaries provided good examples of cooperation, networking and demonstration. The project’s success was due, in large part, to the excellent cooperation between road owners, government agencies and private forest companies. A series of seminars were organised, for example, targeting forest owners, a private road association, consultants and other stakeholders; while project staff attended numerous seminars and conferences with presentations. Knowledge and methods acquired during the project are being used in a range of other projects within the counties of Norrbotten and Västerbotten. They are also being disseminated to stakeholders in other parts of Sweden and neighbouring countries. Two demonstration sites were constructed, which were used for excursions and education for targeted groups. A total of 14 local excursions and 4 family days were organised, attended by 2 916 people.
The project contributed to the improvement of the quality and conservation status of target habitats and species in five Natura 2000 network sites (Råneälven, Piteälven, Torne och Kalix älvsystem, Lögdeälven and Sävarån), so directly implementing the EU Habitats Directive. The project also helps implement the Water Framework Directive, through improvements in water quality. Project results support a range of national and regional policy initiatives. The removal of migration barriers has been identified as a priority at both national and regional scales by the Swedish Agency for Marine and Water Management (SWAM) and regional Water Authorities. The project’s nature conservation approaches have been transferred to the road building industry through the ROADEX network (a collaboration between northern organisations involved with low-volume roads), especially its ideas for overcoming migration barriers when improving or constructing new rural roads.
The economic benefits of the project are mostly related to fishing tourism and ecotourism, both industries having large potential for further growth in northern Sweden. By improving connectivity between watercourses, the project opened up areas that could not previously be reached for fish spawning, feeding, breeding and shelter. This has increased fish populations (salmon and trout) in three water catchment areas, with numbers expected to increase in the other two in the future. Salmon and trout are very important species from the economic point of view, directly contributing to tourism and the rural economy in the region.
Further information on the project can be found in the project's layman report and After-LIFE Conservation Plan (see "Read more" section).
