Keeping close to the river, shore and surface: the first marine migration of brown trout (Salmo trutta) and Arctic charr (Salvelinus alpinus) post-smolts

Acoustic telemetry was utilized to track 49 brown trout ( Salmo trutta ) and 37 Arctic charr ( Salvelinus alpinus ) first-time migrants of wild origin [post-smolts; mean LF (fork length): 169 and 172 mm] in a large fjord in northern Norway. The S. trutta were registered at sea for more than twice th...

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Bibliographic Details
Published in:Journal of Fish Biology
Main Authors: Atencio, Benjamin J., Thorstad, Eva Bonsak, Rikardsen, Audun H., Jensen, Jenny Lovisa Alexandra
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2021
Subjects:
Online Access:https://hdl.handle.net/10037/21709
https://doi.org/10.1111/jfb.14737
Description
Summary:Acoustic telemetry was utilized to track 49 brown trout ( Salmo trutta ) and 37 Arctic charr ( Salvelinus alpinus ) first-time migrants of wild origin [post-smolts; mean LF (fork length): 169 and 172 mm] in a large fjord in northern Norway. The S. trutta were registered at sea for more than twice the time of the S. alpinus (medians of 54 and 22 days, respectively). Both species were mostly detected near river mouths (>80% of detections) and almost exclusively spent their time (>95%) within the interior 18 km of the fjord. They were surface oriented, with most detections at <1 m depth and S. trutta deeper on average (median mean depths of 0.7 and 0.5 m, respectively). This study concludes that post-smolts of both species stay closer to the surface and to river mouths than larger veteran migrants. This study emphasizes the importance of river mouths and upper water layers for the survival of both species during their first marine migration.