Factors influencing return rate and marine residence duration in sea trout populations in central Norway

Overview
TitleFactors influencing return rate and marine residence duration in sea trout populations in central Norway
AuthorsPaterson RA, Berntsen HH, Naesje TF, Berg M, Finstad B
TypeJournal Article
Journal NameJournal of fish biology
VolumeN/A
IssueN/A
Year2021
Page(s)N/A
CitationPaterson RA, Berntsen HH, Naesje TF, Berg M, Finstad B. Factors influencing return rate and marine residence duration in sea trout populations in central Norway. Journal of fish biology. 2021 May 04.

Abstract

Brown trout (Salmo trutta) display extensive plasticity in marine migratory behaviours, with marine migrations considered to be an adaptive strategy which enable sea trout to maximise growth and reproductive potential. However, marine migrations are not without associated costs, including threats posed by ever increasing salmon lice (Lepeophtheirus salmonis) infestations. In the present study, we use passive integrated transponder technology to characterise variability in sea trout migration behaviour amongst three catchments situated in a region of intensive salmon farming in central Norway. Specifically, we investigate how lice infestation, out-migration date and body size alter sea trout return rate and marine residence duration during the first out-migration to sea from each catchment. Distinct catchment-specific differences in sea trout out-migration size and the number of cohorts were observed, however larger body size did not guarantee the successful return of migrating trout. The marine residence duration of individuals that successfully returned to freshwater was positively correlated with lice infestation risk, suggesting for these individuals the lethal infestation threshold had not been reached. Our results also suggest that sea trout populations from lotic-dominated catchments are potentially at greater risk from size-related threats to their survival encountered during their marine migrations than sea trout from lentic-dominated catchments. The variability in sea trout migratory behaviour among catchments observed here emphasises the challenges fisheries managers face when deciding the best actions to take to protect the anadromous portion of brown trout populations. This article is protected by copyright. All rights reserved.

Author Details
Additional information about authors:
Details
1Rachel A Paterson
2Henrik H Berntsen
3Tor F Naesje
4Marius Berg
5Bengt Finstad
Properties
Additional details for this publication include:
Property NameValue
Journal CountryEngland
Publication TypeJournal Article
Language Abbreng
LanguageEnglish
CopyrightThis article is protected by copyright. All rights reserved.
Elocation10.1111/jfb.14770
DOI10.1111/jfb.14770
Journal AbbreviationJ Fish Biol
Publication Date2021 May 04
eISSN1095-8649
ISSN1095-8649
Publication ModelPrint-Electronic
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PMID: PMID:33942297