As part of the Global Swimways initiative that aims to better protect migratory fishes, IUCN, the UN Environment Programme World Conservation Monitoring Centre, the University of Cambridge and the World Fish Migration Foundation, came together to create the first global map of fish migration routes around the world. The mapping was based on 665 migratory fish species, focusing on Europe and Africa, where the most updated distribution maps were available .
A selection of case studies, specific to Europe and Africa, were completed to visualize fully informed Swimways, as proposed for all migration routes through the full Global Swimways 2 project. This included compilation of more detailed data on the freshwater migratory fishes specific to each region, based on data from GROMS, Fishbase, IUCN and species experts (see this link for the working-list of freshwater migratory fish). Building on the species distribution data obtained from the IUCN Red List of Threatened SpeciesTM database this additional information was used to determine the migration routes for each species in more detail within each case study. It is important to note that these migration routes do not yet account for instream barriers, detailed migration behaviours based on telemetry, or other potential influencing factors. These refinements are proposed for incorporation through follow up projects, such as Global Swimways 2.