Ascent ability of brown trout, Salmo trutta , and two Iberian cyprinids − Iberian barbel, Luciobarbus bocagei , and northern straight-mouth nase, Pseudochondrostoma duriense − in a vertical slot fishway

Passage performance of brown trout ( Salmo trutta ), Iberian barbel ( Luciobarbus bocagei ), and northern straight-mouth nase ( Pseudochondrostoma duriense) was investigated in a vertical slot fishway in the Porma River (Duero River basin, Spain) using PIT telemetry. We analysed the effects of different fishway discharges on motivation and passage success. Both cyprinid species ascended the fishway easily, performing better than the trout despite their theoretically weaker swimming performance. Fishway discharge affected fish motivation although it did not clearly influence passage success. Observed results can guide design and operation criteria of vertical slot fishways for native Iberian fish.