During their early life stages (egg maturation, hatching, alevin development), between late autumn and early spring, young Atlantic salmon are exposed to surface‐groundwater interactions in the hyporheic zone and may depend on influx of subsurface water during periods of regulated low discharge for survival. Two studies, one in a seasonally regulated river and one in a river exposed to hydropeaking, displayed unexpectedly high...

Recent findings on the causes of Atlantic salmon embryo mortality during winter in a hydropeaking river suggest that long duration drawdowns during very cold periods are the most likely cause of mortality in the ramping zone. This paper presents a framework in which thresholds for optimal embryo survival at the microscale are linked to physical habitat requirements at the mesoscale and integrated into alternative hydropower op...

Studies on downstream passage of diadromous fishes in northern E urope are rare, and in N orway, the problem is strongly linked to demands for efficient hydropower production. The current study explored mitigating measures using a hydropower simulation model for A tlantic salmon, S almo salar L., smolt migration. Migration pattern and route choice at a hydropower intake for 22 years were described for a river in southern N orw...

There is an increasing demand for tools to assist in the management of environmental flows in rivers. Changes in river discharge act on biota through a hydraulic template, which is mediated by channel morphology. Hence, environmental flow assessments also need to consider channel morphology, especially if morphology has been altered by human activities. Computer models describing the preferences of fish for hydraulic microhabi...

The effect of anchor‐ice dams on the physical habitat and behavioural responses of Atlantic salmon Salmo salar parr in a small, steep stream was investigated. Anchor‐ice dams formed periodically, leading to a dynamic winter environment as the study reach alternated between riffle and walk dominated habitat. Parr demonstrated large individual variation in habitat use, utilizing most of the wetted stream width, and were generall...