The survival of semi‐wild, wild and hatchery‐reared Atlantic salmon smolts of the Simojoki River in the Baltic Sea |
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| Authors: | E. Jokikokko&dagger ,I. Kallio&# Nyberg&Dagger ,I. Saloniemi§ , E. Jutila¶ |
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| Affiliation: | Finnish Game and Fisheries Institute, Bothnian Bay Fisheries Research Station, Jenssintie 2, FIN‐95200 Simo, Finland;, Finnish Game and Fisheries Institute, Quark Fisheries Research Station, Korsholmanpuistikko 16, FIN‐65100 Vaasa, Finland;, Department of Biology, Laboratory of Genetics, University of Turku, FIN‐20014 Turku, Finland and;;Finnish Game and Fisheries Institute, P. O. Box 2, FIN‐00791 Helsinki, Finland |
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| Abstract: | The recapture rate and survival of hatchery‐reared Atlantic salmon Salmo salar stocked as 1 year‐old parr (semi‐wild) with that of hatchery‐reared Atlantic salmon stocked as 2 year‐old smolts and wild smolts of Atlantic salmon in the northern Baltic Sea were compared. This was done through tagging experiments carried out in 1986–1988 and 1992. The recapture rate of the semi‐wild groups varied from 1·0 to 13·1%, being similar in 3 tagging years and lower in 1 year than that of the wild groups (1·7–17·0%). The recapture rate of the semi‐wild groups was similar (in 2 years) or higher (in 2 years) than that of the hatchery‐reared groups stocked as smolts (1·3–6·3%). The survival of semi‐wild smolts during the sea migration was as high as that of wild Atlantic salmon of an equal size and two to three times higher than hatchery‐reared Atlantic salmon stocked as smolts. The survival rate was positively associated with smolt size. The suitability of hatchery‐reared parr and smolts in the management of reduced Atlantic salmon stocks is compared. |
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| Keywords: | parr Salmo salar smolt stocking survival |
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