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This pilot study used programmed acoustic tags implanted into S. salar smolts, in conjunction with an extensive offshore marine receiver array, to investigate late-stage migratory behaviour and survival of returning adult salmon. 100 smolts were tagged in 2020 and a number of individuals were successfully detected as returning adults in 2021. After accounting for detection efficiency, 5-9 adults were estimated to have returned to the offshore array c. 45km from the river mouth. 3 fish were subsequently detected in the river. Losses of between 40-66% were evident during the final stages of ocean migration and one tagged fish provided direct evidence of a predation event. This article is protected by copyright. All rights reserved. |
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