The Azores is the most west located distribution area for European eel (Anguilla anguilla) and closest to the spawning grounds presumably in the Sargasso Sea. Being almost in the middle of the Atlantic Ocean and consisting of an archipelago of volcanic islands with small streams running dry during periods of low to no precipitation, it is a unique system across the European-wide habitat range for European eels. In fact, it is the only native teleost inhabiting the freshwater systems on the Azores. As the species is considered a symbol for global change, knowledge on its ecology can be used to assess human impact on aquatic systems. In this project, we track the silver eels in a stream during their migration to the sea.