Data from: Reduced fitness of Atlantic salmon released in the wild after one generation of captive-breeding

• Main Authors: Milot, Emmanuel, Perrier, Charles, Papillon, Lucie, Dodson, Julian J., Bernatchez, Louis
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2012
• Subjects: Captive Populations; Salmo salar; Conservation Biology; Atlantic salmon
• Online Access: https://doi.org/10.5061/dryad.4k739

Salmonids rank among the most socio-economically valuable fishes and the most targeted species by stocking with hatchery-reared individuals. Here, we used molecular parentage analysis to assess the reproductive success of wild- and hatchery- born Atlantic salmon over three consecutive years in a small river in Québec. Yearly restocking in this river follows a single generation of captive breeding. Among the adults returning to the river to spawn, between 11% and 41% each year were born in hatchery. Their relative reproductive success (RRS) was nearly half that of wild-born fish (0.55). RRS varied with life stage, being 0.71 for fish released at the fry stage and 0.42 for fish released as smolt. The lower reproductive success of salmon released as smolt was partly mediated by modification of the proportion of single-sea-winter/multi-sea-winter fish. Overall, our results suggest that modifications in survival and growth rates alter the life-history strategies of these fish at the cost of their reproductive success. Our results underline the potential fitness decrease, warn on long-term evolutionary consequences for the population of repeated stocking and support the adoption of more natural rearing conditions for captive juveniles and their release at a younger stage, such as unfed fry. MILOTEVA2012DATA Genotypes at 8 microsatellite loci (coded by three digits) of adults and juveniles Salmo salar sampled in the Malbaie River from 2002 to 2005 and and at the local hatchery (order explained in the first line of the file).