This article looks at the governance of two highly migratory fish species: European eel (Anguilla anguilla) and Atlantic salmon (Salmo salar). Based on a long ethnographic field survey, this paper proposes to analyse the modalities of fisheries and stock governments in continental and ultramarine Europe (Western France and French Saint-Pierre and Miquelon Archipelago), demonstrating the globalisation faced by these species and their catch and consumption chains. As declining species, their protection was put at the top of the agenda in the second half of the 20th century, but problems appeared much earlier. Contemporary public action is therefore taking a close interest in these two species, and is trying to put in place, using various instruments, appropriate public policies. But these policies are often based on pre-existing policies, instead of being inspired by other modes of government, which are now being promoted outside the western political field by a growing diversity of actors.