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.
anadromous, charr, fjord, marine, migration, post-smolt, salmonid, trout
