Sex-specific Atlantic salmon upstream passage and fallback at a natural cascade after dam removal

Heim, Kurt C.; Withers, Jonah; Arden, William; Earley, Laurie; Minkoff, David; Castro-Santos, Theodore
In the Boquet River (NY, USA) a low-head dam set above a ~200-m bedrock cascade was removed in 2015. We used radio-telemetry to assess landlocked Atlantic salmon passage at the remaining cascade (2020, 2022). Across years, 52% of males (13/25) attempted cascade passage whereas females made no discernable attempts (0/11). Attempt probability increased with stream discharge and decreased with fish size, though overall passage success was low (1/36). Shallow depths—likely owing to an artificially w