Reproductive success of captively bred and naturally spawned Chinook salmon colonizing newly accessible habitat

Evolutionary Applications

Joseph H. Anderson³  Paul L. Faulds²  William I. Atlas¹ 

[1] School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, USA;Seattle Public Utilities, Seattle, WA, USA;Northwest Fisheries Science Center, National Marine Fisheries Service, Seattle, WA, USA

关键词: conservation;    dams;    hatchery;    natural selection;    pedigree;    reintroduction;    sexual selection;   

DOI  :  10.1111/j.1752-4571.2012.00271.x

来源: Wiley

【 摘 要 】

Abstract

Captively reared animals can provide an immediate demographic boost in reintroduction programs, but may also reduce the fitness of colonizing populations. Construction of a fish passage facility at Landsburg Diversion Dam on the Cedar River, WA, USA, provided a unique opportunity to explore this trade-off. We thoroughly sampled adult Chinook salmon (Oncorhynchus tshawytscha) at the onset of colonization (2003–2009), constructed a pedigree from genotypes at 10 microsatellite loci, and calculated reproductive success (RS) as the total number of returning adult offspring. Hatchery males were consistently but not significantly less productive than naturally spawned males (range in relative RS: 0.70–0.90), but the pattern for females varied between years. The sex ratio was heavily biased toward males; therefore, inclusion of the hatchery males increased the risk of a genetic fitness cost with little demographic benefit. Measurements of natural selection indicated that larger salmon had higher RS than smaller fish. Fish that arrived early to the spawning grounds tended to be more productive than later fish, although in some years, RS was maximized at intermediate dates. Our results underscore the importance of natural and sexual selection in promoting adaptation during reintroductions.

【 授权许可】

CC BY-NC   
© 2012 The Authors. Evolutionary Applications published by Blackwell Publishing Ltd.

Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.