Sea trout adapt their migratory behaviour in response to high salmon lice concentrations

Overview
TitleSea trout adapt their migratory behaviour in response to high salmon lice concentrations
AuthorsHalttunen E, Gjelland KØ, Hamel S, Serra-Llinares RM, Nilsen R, Arechavala-Lopez P, Skarðhamar J, Johnsen IA, Asplin L, Karlsen Ø, Bjørn PA, Finstad B
TypeJournal Article
Journal NameJournal of fish diseases
VolumeN/A
IssueN/A
Year2017
Page(s)N/A
CitationHalttunen E, Gjelland KØ, Hamel S, Serra-Llinares RM, Nilsen R, Arechavala-Lopez P, Skarðhamar J, Johnsen IA, Asplin L, Karlsen Ø, Bjørn PA, Finstad B. Sea trout adapt their migratory behaviour in response to high salmon lice concentrations. Journal of fish diseases. 2017 Nov 21.

Abstract

Sea trout face growth-mortality trade-offs when entering the sea to feed. Salmon lice epizootics resulting from aquaculture have shifted these trade-offs, as salmon lice might both increase mortality and reduce growth of sea trout. We studied mortality and behavioural adaptations of wild sea trout in a large-scale experiment with acoustic telemetry in an aquaculture intensive area that was fallowed (emptied of fish) synchronically biannually, creating large variations in salmon lice concentrations. We tagged 310 wild sea trout during 3 years, and gave half of the individuals a prophylaxis against further salmon lice infestation. There was no difference in survival among years or between treatments. In years of high infestation pressure, however, sea trout remained closer to the river outlet, used freshwater (FW) habitats for longer periods and returned earlier to the river than in the low infestation year. This indicates that sea trout adapt their migratory behaviour by actively choosing FW refuges from salmon lice to escape from immediate mortality risk. Nevertheless, simulations show that these adaptations can lead to lost growth opportunities. Reduced growth can increase long-term mortality of sea trout due to prolonged exposure to size-dependent predation risk, lead to lower fecundity and, ultimately, reduce the likelihood of sea migration.

Properties
Additional details for this publication include:
Property NameValue
Publication ModelPrint-Electronic
ISSN1365-2761
eISSN1365-2761
Publication Date2017 Nov 21
Journal AbbreviationJ. Fish Dis.
DOI10.1111/jfd.12749
Elocation10.1111/jfd.12749
Copyright© 2017 The Authors. Journal of Fish Diseases Published by John Wiley & Sons Ltd.
LanguageEnglish
Language Abbreng
Publication TypeJournal Article
Journal CountryEngland
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DatabaseAccession
PMID: PMID:29159923