Abstract
The brown trout (Salmo trutta) is an iteroparous, anadromous salmonid that exhibits a complex continuum of feeding migration tactics, ranging from freshwater residency, to potamodromy, to estuarine migration, as well as short-to long-distance coastal migrations. While anadromous migrants are believed to play an important role in the species’ population dynamics, little is known about the factors driving differences in the extent of individual marine habitat use. In this study, 32 brown trout veteran migrants were acoustically tagged prior to their seaward migration and sampled for indices of their nutritional state. Our findings suggest that (i) body condition factor differed among fish adopting different migratory tactics, with outer fjord migrant being in poorer condition; and (ii) within migratory groups, plasma triglyceride concentration was negatively correlated with the duration of marine residency. Results support the idea of condition-dependent migration in veteran migrants, with individual variation in nutritional state influencing the spatiotemporal aspects of marine habitat use. Furthermore, overall marine minimum survival during the summer feeding migration was 86%, the highest reported estimate for this life stage.
| Original language | English |
|---|---|
| Pages (from-to) | 1744-1754 |
| Number of pages | 11 |
| Journal | Canadian Journal of Fisheries and Aquatic Sciences |
| Volume | 75 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - 2018 |
Bibliographical note
Funding Information:This study was financed or supported by contributions from Sinkaberg-Hansen AS, the County Governor of Nordland, Nordland County Authority, the Norwegian Environment Agency, the River Åbjøra landowners’ association, Plathes Eiendommer, and the NTNU University Museum. Additional support was provided by the Ocean Tracking Network via a Travel Grant to XB, a loan of acoustic receivers to JGD, a Natural Sciences and Engineering Research Council of Canada Discovery Grant to GTC, and a Canada Graduate Scholarship to XB. The crew of RV Gunnerus, Lars Rønning, Jan Ivar Koksvik, Embla Østebrøt, and Hilde Dørum, are all thanked for their extensive help during the field work. Marc Daverdin at the NTNU University Museum is thanked for assistance with making the maps.
Funding Information:
This study was financed or supported by contributions from Sinkaberg-Hansen AS, the County Governor of Nordland, Nord-land County Authority, the Norwegian Environment Agency, the River Åbjøra landowners’ association, Plathes Eiendommer, and the NTNU University Museum. Additional support was provided by the Ocean Tracking Network via a Travel Grant to XB, a loan of acoustic receivers to JGD, a Natural Sciences and Engineering Research Council of Canada Discovery Grant to GTC, and a Canada Graduate Scholarship to XB. The crew of RV Gunnerus, Lars Rønning, Jan Ivar Koksvik, Embla Østebrøt, and Hilde Dørum, are all thanked for their extensive help during the field work. Marc Daverdin at the NTNU University Museum is thanked for assistance with making the maps.
Publisher Copyright:
© 2018, Canadian Science Publishing. All rights reserved.
ASJC Scopus Subject Areas
- Ecology, Evolution, Behavior and Systematics
- Aquatic Science
