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Gene flow from domesticated escapes alters the life history of wild Atlantic salmon

Nature Ecology & Evolution volume 1, Article number: 0124 (2017) | Download Citation

Abstract

Interbreeding between domesticated and wild animals occurs in several species. This gene flow has long been anticipated to induce genetic changes in life-history traits of wild populations, thereby influencing population dynamics and viability. Here, we show that individuals with high levels of introgression (domesticated ancestry) have altered age and size at maturation in 62 wild Atlantic salmon Salmo salar populations, including seven ancestral populations to breeding lines of the domesticated salmon. This study documents widespread changes to life-history traits in wild animal populations following gene flow from selectively bred, domesticated conspecifics. The continued high abundance of escaped, domesticated Atlantic salmon thus threatens wild Atlantic salmon populations by inducing genetic changes in fitness-related traits. Our results represent key evidence and a timely warning concerning the potential ecological impacts of the globally increasing use of domesticated animals.

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Acknowledgements

We thank G. M. Østborg and J. G. Jensås for scale reading, T. Balstad, L. B. Eriksen and M. H. Spets for genetic analyses and J. D. Linnell for discussion. The study was financed by the Research Council of Norway (grant 216105, QuantEscape), the Norwegian Environment Agency and the Norwegian Institute for Nature Research.

Author information

Affiliations

  1. Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway

    • Geir H. Bolstad
    • , Kjetil Hindar
    • , Grethe Robertsen
    • , Ola H. Diserud
    • , Peder Fiske
    • , Arne J. Jensen
    • , Tor F. Næsje
    •  & Sten Karlsson
  2. Norwegian Institute for Nature Research (NINA), NO-0349 Oslo, Norway

    • Bror Jonsson
  3. Radgivende Biologer, NO-5003 Bergen, Norway

    • Harald Sægrov
    •  & Kurt Urdal
  4. Uni Research, NO-5006 Bergen, Norway

    • Bjørn T. Barlaup
  5. Norwegian Veterinary Institute, NO-7485 Trondheim, Norway

    • Bjørn Florø-Larsen
    •  & Håvard Lo
  6. Natural Resources Institute Finland, FI-90014 Oulu, Finland

    • Eero Niemelä

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Contributions

G.H.B., K.H., O.H.D. and S.K. conceived the study. S.K. and O.H.D. generated and conducted bioinformatics on the molecular data. K.H., H.S., P.F., A.J.J., K.U., T.F.N., B.T.B., B.F.-L., H.L. and E.N. coordinated the collection of phenotypic data. G.H.B. analysed the data. G.H.B., K.H., G.R., B.J. and S.K. wrote the manuscript. All authors read and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Geir H. Bolstad.

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    Supplementary Figures 1,2; Supplementary Tables 1–4; Supplementary Methods; Supplementary References

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DOI

https://doi.org/10.1038/s41559-017-0124

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