In this presentation, we studied demography and movement of two Japanese landlocked salmonids (white-spotted charr Salvelinus leucomanie japonicusand red-spotted masu salmon Oncorhynchus masou ishikawae) persisting for > 30 years in a headwater stream network that is highly fragmented due to low-head dams in the mainstem (six impassable infrastructures in a < 500 m segment).