Reproductive success of captively bred and naturally spawned Chinook salmon colonizing newly accessible habitat
Version of Record online: 11 JUN 2012
© 2012 The Authors. Evolutionary Applications published by Blackwell Publishing Ltd.
This is an open access article under the terms of the 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.
Volume 6, Issue 2, pages 165–179, February 2013
How to Cite
Anderson, J. H., Faulds, P. L., Atlas, W. I. and Quinn, T. P. (2013), Reproductive success of captively bred and naturally spawned Chinook salmon colonizing newly accessible habitat. Evolutionary Applications, 6: 165–179. doi: 10.1111/j.1752-4571.2012.00271.x
- Issue online: 18 FEB 2013
- Version of Record online: 11 JUN 2012
- Manuscript Accepted: 2 APR 2012
- Manuscript Received: 23 MAR 2012
- National Oceanic and Atmospheric Administration . Grant Numbers: NA04OAR4170032, NA07OAR4170007, R/F-148 and R/F-159
- Seattle Public Utilities
- H Mason Keeler Endowment
- natural selection;
- sexual selection
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.