Environmental influences of life history strategies in partial anadromous brown trout (Salmo trutta, Salmonidae)

This paper reviews the life history of brown trout and factors influencing decisions to migrate. Decisions that maximize fitness appear dependent on size at age. In partly anadromous populations, individuals that attain maturity at the parr stage typically become freshwater resident. For individual...

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Bibliographic Details
Published in:Fish and Fisheries
Main Authors: Nevoux, Marie, Finstad, Bengt, Davidsen, Jan Grimsrud, Finlay, Ross, Josset, Quentin, Poole, Russell, Hojesjo, Johan, Aarestrup, Kim, Persson, Lo, Tolyanen, Oula, Jonsson, Bror
Other Authors: Écologie et santé des écosystèmes (ESE), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Norwegian Institute for Nature Research (NINA), Department of Natural History, University Museum, Marine Institute, Direction de la Recherche, de l’Expertise et des données, Agence Française pour la Biodiversité (AFB), Department of Biological and Environmental Sciences, National Institute of Aquatic Resources, Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences (SLU), The Water Protection Association of the River Vantaa and Helsinki Region, Department of Landscape Ecology
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2019
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Online Access:https://hal.archives-ouvertes.fr/hal-02501450
https://doi.org/10.1111/faf.12396
Description
Summary:This paper reviews the life history of brown trout and factors influencing decisions to migrate. Decisions that maximize fitness appear dependent on size at age. In partly anadromous populations, individuals that attain maturity at the parr stage typically become freshwater resident. For individual fish, the life history is not genetically fixed and can be modified by the previous growth history and energetic state in early life. This phenotypic plasticity may be influenced by epigenetic modifications of the genome. Thus, factors influencing survival and growth determine life-history decisions. These are intra- and interspecific competition, feeding and shelter opportunities in freshwater and salt water, temperature in alternative habitats and flow conditions in running water. Male trout exhibit alternative mating strategies and can spawn as a subordinate sneaker or a dominant competitor. Females do not exhibit alternative mating behaviour. The relationship between growth, size and reproductive success differs between sexes in that females exhibit a higher tendency to migrate than males. Southern populations are sensitive to global warming. In addition, fisheries, aquaculture with increased spreading of salmon lice, introduction of new species, weirs and river regulation, poor water quality and coastal developments all threaten trout populations. The paper summarizes life-history data from six populations across Europe and ends by presenting new research questions and directions for future research.