The early marine migratory behaviour of two populations of hatchery‐reared Atlantic salmon Salmo salar was compared in a common‐garden experiment. Post‐smolts from a river in a long fjord (Lærdal River, 144 km from the open coastline, n = 79) and a short fjord (Flekke River, 20 km from the open coastline, n = 80) in western Norway were tagged with acoustic transmitters and released during the spring of 2005 and 2006 in the inn...

The migratory behaviour of hatchery‐reared Atlantic salmon, Salmo salar L., post‐smolts during the first phase of the marine migration was examined to assess their susceptibility to salmon lice, Lepeophtheirus salmonis (Krøyer), infestations. Swimming depths of eight post‐smolts relative to the measured salinity and temperature were monitored for an average of 11.4 h following release outside the mouth of the River Eio using d...

Eight hatchery‐reared Atlantic salmon Salmo salar post‐smolts, implanted with acoustic depth sensing transmitters and manually tracked for 5–12 h in the Hardangerfjord (Norway), spent most of their time (49–99%) at 1–3 m depth during the day, whereas four of seven fish tracked were found close (

Eighty coho salmon Oncorhynchus kisutch smolts (40 wild and 40 hatchery‐reared) were surgically implanted with acoustic transmitters and released into the Quinsam River over 2 days. Differences in physiology, travel time and migratory behaviour were examined between wild and hatchery‐reared fish. In addition, tagged and control fish of both wild and hatchery‐reared stock were raised for 3 months following surgery to compare su...