Global swimways
This map viewer is part of the Global Swimways initiative which aims to connect fish, rivers and people globally using a proposed Swimways programme. A Global Swimway is yet to be formally defined but is taken to mean rivers and their associated ecosystems that support the entire migration routes of biologically and/or socio-economically important freshwater fishes. Here we have mapped Global Swimways based on presence of migratory freshwater fish in rivers for all fully assessed IUCN species. Mapping these migration routes helps cooperation to protect the fish from sea to source. A paper (Worthington&van Soesbergen et al., 2022) detailing the concept can be found here This project is a collaboration between IUCN, UNEP-WCMC, WWF, University of Cambridge and the World Fish Migration Foundation. More info on the project can be found hereThis project received funding from:
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The data provided on this site is for informational purposes only.
Absolutely no accuracy or completeness guarantee is implied or intended. The designations employed and the presentation of material on this map do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.
These maps are for demonstration purposes only. The maps use freshwater migratory species ranges derived from the IUCN red list database (IUCN, 2020). These data were filtered for migratory species based on a list of 907 known migratory species. Species were selected if their ranges were coded as extant and possibly extant, and origin native and reintroduced resulting in a total of 665 species. For some species, distribution data was not available and thus not included. For example, for North America, no Salmonids are included currently.
Each individual species range was used to clip the Hydrorivers (V1.0) data set ( Lehner and Grill, 2013 ) to obtain all river reaches (mean length = 4.23 km) within that range. Hydrorivers data was used as it is part of the Hydrobasins ( Lehner and Grill, 2013 ) data that is also used in the IUCN freshwater species assessment process. These were then filtered for larger river reaches by selecting only reaches with flow orders above 5 (long term average discharge of ≥ 10 m3/s). For each of those river segments, the total number of species whose ranges overlap with that segment were calculated.
In addition to the analysis for all species, layers were produced showing only endemic species, defined as species whose range are fully within Hydrobasins level 4 (91 species) and threatened species, by selecting threat status (critically endangered, endangered and vulnerable) in the range data (109 species total)
The threat layers include data on large dams from the GOODD (Mulligan et al., 2020) and GrAND (Lehner et al., 2011) datasets. Dam data was obtained from Global dam watch
If you would like to get in touch with us, please send us an e-mail on: info@globalswimways.org