Salmon disappeared from the Swiss Rhine about 50 years ago, due to poor water quality and the construction of hydro-electric power plants. Huge efforts have been made to bring the fish back, but major hurdles still stand in the way. (Julie Hunt, swissinfo.ch/SRF/WWF)
The river has now been cleaned up and spawning grounds have been created for salmon. Most Rhine bordering countries, apart from France, have built fish passes around all their power plants to help migrating fish to swim upstream. The French are now coming under heavy pressure to comply.