Data from: Supplementary stocking selects for domesticated genotypes

Stocking of hatchery produced fish is common practise to mitigate declines
in natural populations and may have unwanted genetic consequences. Here we
describe a novel phenomenon arising where broodstock used for stocking may
be introgressed with farmed individuals. We test how stocking affects
introgression in a wild population of Atlantic salmon (Salmo salar) by
quantifying how the number of adult offspring recaptured in a stocked
river depend on parental introgression. We found that hatchery conditions
favour farmed genotypes such that introgressed broodstock produce up to
four times the number of adult offspring compared to non-introgressed
broodstock, leading to increased introgression in the recipient spawning
population. Our results provide the first empirical evidence that stocking
can unintentionally favour introgressed individuals and through selection
for domesticated genotypes compromise the fitness of stocked wild
populations.