A1 Refereed original research article in a scientific journal
Distribution and biological characteristics of escaped farmed salmon in a major subarctic wild salmon river: implications for monitoring
Authors: Erkinaro J, Niemela E, Vaha JP, Primmer CR, Brors S, Hassinen E
Publisher: CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS
Publication year: 2010
Journal: Canadian Journal of Fisheries and Aquatic Sciences
Journal name in source: CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES
Journal acronym: CAN J FISH AQUAT SCI
Number in series: 1
Volume: 67
Issue: 1
First page : 130
Last page: 142
Number of pages: 13
ISSN: 0706-652X
DOI: https://doi.org/10.1139/F09-173
Abstract
We report the occurrence, distribution, and biological characteristics of escaped farmed salmon in the River Teno in northernmost Europe, which supports one of the largest and most versatile wild Atlantic salmon (Salmo salar) populations in the world. Farmed salmon were caught during the fishing season (May-August) when their proportion in the catch varied between 0.0% and 0.7%. Occasional sampling after the fishing season revealed much higher proportions of escapees, up to 47%, indicating a potential for a more severe impact of farmed fish than the in-season monitoring is able to uncover. Peak migration of the wild salmon was in June or July, but that of escaped farmed fish was in August. Up to 88% of the escaped salmon caught in August showed gonad development, and scale analysis indicated that 4.5% of them were repeat spawners. Genetic analyses using microsatellite markers revealed highly significant genetic differentiation between wild salmon and escaped farmed fish (F(ST) = 0.05) caught in the River Teno and a Norwegian farmed strain (F(ST) = 0.10). The heterogeneity of escapees compared with the single farmed strain indicated that escapees apparently originate from multiple sources, which will complicate their genetic identification and the assessment of the level of hybridization with wild salmon.
We report the occurrence, distribution, and biological characteristics of escaped farmed salmon in the River Teno in northernmost Europe, which supports one of the largest and most versatile wild Atlantic salmon (Salmo salar) populations in the world. Farmed salmon were caught during the fishing season (May-August) when their proportion in the catch varied between 0.0% and 0.7%. Occasional sampling after the fishing season revealed much higher proportions of escapees, up to 47%, indicating a potential for a more severe impact of farmed fish than the in-season monitoring is able to uncover. Peak migration of the wild salmon was in June or July, but that of escaped farmed fish was in August. Up to 88% of the escaped salmon caught in August showed gonad development, and scale analysis indicated that 4.5% of them were repeat spawners. Genetic analyses using microsatellite markers revealed highly significant genetic differentiation between wild salmon and escaped farmed fish (F(ST) = 0.05) caught in the River Teno and a Norwegian farmed strain (F(ST) = 0.10). The heterogeneity of escapees compared with the single farmed strain indicated that escapees apparently originate from multiple sources, which will complicate their genetic identification and the assessment of the level of hybridization with wild salmon.
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