Migratory behaviour of wild and farmed Atlantic salmon (Salmo salar) during spawning |
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Authors: | F Økland T G Heggberget B Jonsson |
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Institution: | Norwegian Institute for Nature Research, Tungasletta 2, N-7005 Trondheim, Norway |
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Abstract: | Migratory behaviour at spawning of wild and newly-escaped farmed Atlantic salmon was analysed by radio telemetry in the River Alta, North Norway. Spawning areas were located by aerial surveys. Farmed females moved significantly more than wild females ( P <0.01). There was no such difference between the two groups of males. About 83% of the wild fish stayed within identified spawning areas for 1 day or longer. The corresponding figure for farmed salmon was only 43% ( P <0.05). Wild salmon stayed 8.1 days inside spawning areas and farmed salmon 5.2 days. The present results suggest that escaped farmed salmon had reduced spawning success compared with wild fish. |
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Keywords: | Salmo salar fish farm escapees migratory behaviour |
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