In most river systems, fragmentation of the longitudinal corridor (by dams, weirs, locks, culverts...) has resulted in the drastic reduction and the disappearance of numerous migratory fish species. At present, efforts are made to remediate these problems by use of fish passes and bypass channels in order to resto re the accessibility of upstream areas to fish. Assessing the swimming capacity of endemic fish species will allow the development of an integrated model to predict the accessibility of barriers to fish, which can be used as a management tool for river management.