Last week a group of people from the Fish Passage 2015-team, World Fish Migration Foundation and WWF-Netherlands visited the River Ätran in Southern Sweden. Herting, the hydropower plant located most downstream in the system, has been subject to extensive efforts to improve fish passage. A dam structure has been removed and a large nature-like fishway constructed to facilitate both upstream and downstream passage (as well as supply salmon and other fish with additional spawning habitat) and a low sloping rack has been installed to guide downstream migrating fish to a by-pass entrance by the turbine intakes. Passing migratory fish include Atlantic salmon, brown trout, sea lamprey and European eel. Olle Calles, researcher at NRRV and Karlstad University, has been involved throughout the processes and presented pre- and post-remediation data on fish-passage and told the story about salmon population in the river. The group also visited a monitoring trap and spawning areas in the River Högvadsån, a tributary to the River Ätran and was given the opportunity to track radio tagged eel in an ongoing study on eel downstream migration and dam passage. We appreciate the visit and the interesting discussions taking place throughout their stay.

Herting hydropower plant, the naturelike fishway to the right and the intake channel to the left. In the end of the intake channel, there is a low sloping rack to guide the fish to the by-pass entrance. In the naturelike fishway the upstream migrating fish are guided to a narrow area to facilitate monitoring. (Foto from a film by Fiskevårdsteknik)

The group at the monitoring trap in the tributary Högvadsån. Present in the photo is also a visiting journalist from Swedish National Radio (SR). Mr. Möller is managing the trap.

A salmon caught and displayed at the monitoring trap.

Tracking radio-tagged eel in the River Ätran.

Fiskvägen vid Geesthacht i Elbe.

Under förra veckan organiserades Fish Passage – International conference on river connectivity best practices and innovations i Groningen, Nederländerna. Konferensen innehöll en mängd presentationer om fiskvandring och fiskpassage. Presentatörerna var biologer, ingenjörer, forskare och branschfolk och kom från sex olika världsdelar. NRRV och Karlstads Universitet var väl repressenterat: Larry Greenberg var moderator för en keynote session och presenterade “Conservation of a landlocked salmonid population in a regulated river: Taking a holistic approach”. Olle Calles var en av konferensens huvudorganisatörer och presenterade “On the performance of a new upstream and downstream passage facility for diadromous fish species” samt “A telemetry study on marble trout (Salmo marmoratus) and Italian barbel (Barbus plebejus) at a nature-like fish ramp in an Alpine river”. Stina Gustafsson var med i konferensens Advisory board och presenterade “Habitat compensation in a nature-like fishway”. Min egen presentation hade titeln “Postspawning survival and downstream passage of landlocked Atlantic salmon (Salmo salar) in a regulated river: Is there potential for repeat spawning?”. Konferensens abstracts kan läsas här

Under helgen innan konferensen gavs fem kurser på temat fiskpassage, närmare bestämt Dam removal, Downstream Passage, Techinical and Nature-like fishway designs, Fishway evaluations och Integrating Fish Passage in Watershed Restoration Plans: How to prioritize actions and monitor their effectiveness. Olle Calles var en av kursledarna på kursen om nedströmspassage.

Konferensen avslutades med studiebesök vid nederländska fiskvägar, slussar och tidvattensbarriärer. Eller till Elbe och en av Europas största fiskvägar vid dammen i Geesthacht utanför Hamburg.