Author(s): Olivia M. Simmons; Ana T. Silva; Torbjorn Forseth; Patrik Andreasson; Stephanie Muller; Olle Calles; David Aldven
Linked Author(s): Stephanie Mueller
Keywords: No Keywords
Abstract: Atlantic salmon kelts must navigate past dams in hydropower-regulated rivers to complete their migrations. Yet, hydropower dams can block their passage and cause delays during migration. Here, we present the results of a field study to understand passage performance and swimming speeds of kelts upstream of a hydropower dam in relation to varying hydraulic conditions. To do so, we used movement data from kelts tagged with acoustic transmitters and hydraulic data from CFD models. We found that as dam operations changed over the study period, the hydraulic conditions in the river also changed. Changes in these conditions acted as a navigation cue for kelts to find a safe route past the dam. Kelt swimming speed increased with body length, and they swam faster as water velocity increased, but slower as turbulence intensity increased.
Year: 2024