Data from: Introgression from farmed escapees affects the full life cycle of wild Atlantic salmon

After a half a century of salmon farming, we have yet to understand how
the influx of genes from farmed escapees affects the full life history of
Atlantic salmon (Salmo salar L.) in the wild. Using scale samples of over
6900 wild adult salmon from 105 rivers, we document that increased farmed
genetic ancestry is associated with increased growth throughout life and a
younger age at both seaward migration and sexual maturity. There was large
among-population variation in the effects of introgression. Most
saliently, the increased growth at sea following introgression declined
with the population’s average growth potential. Variation at two
major-effect loci previously shown to be associated with age at maturity
was little affected by farmed genetic ancestry and could not explain the
observed phenotypic effects of introgression. Our study provides knowledge
crucial for redicting the ecological and evolutionary consequences of
increased aquaculture production worldwide.