Abstract Twenty five silver American eels, Anguilla rostrata (Lesueur), were sonically tagged to determine the passage success at a recently reconstructed hydroelectric facility on the Magaguadavic River, and to explore the environmental correlates of surviving eel movements through the coastal zone to the Bay of Fundy. Downstream movements of many eels were delayed at the dam and tagged fish moved extensively in the reservoir, presumably searching for an exit. All 19 eels that entered the turbines died. Six eels survived by passing the dam either via a fish bypass chute (4), by spilling over the dam (1), or through a fish ladder for upstream migrating fish (1). Coastal zone movements of 20 control eels released downstream of the dam, and of the six survivors, were linked to environmental parameters (tides, luminosity). The efficiency of the downstream fish bypass at this site might be improved by altering water management strategies.