Abstract
Smolt migration through a shallow and turbid hydro‐reservoir in a major Danish river system was investigated using radiotelemetry. Hatchery‐reared 1+‐year‐old Atlantic salmon, Salmo salar L., smolts of equal size from two different non‐native strains were radio‐tagged and followed during their downstream migration through the 12‐km‐long reservoir. A total of 50 salmon smolts, 25 of Swedish (Øtran River) and 25 of Irish (Burrishoole River) origin, were surgically implanted with miniature radiotransmitters. The tagged smolts were tracked daily over a 3‐week period in May 1996. The Øtran smolts initiated migration first ( P P P