Can interbreeding of wild and artificially propagated animals be prevented by using broodstock selected for a divergent life history?
Article first published online: 28 FEB 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 5, Issue 7, pages 705–719, November 2012
How to Cite
Seamons, T. R., Hauser, L., Naish, K. A. and Quinn, T. P. (2012), Can interbreeding of wild and artificially propagated animals be prevented by using broodstock selected for a divergent life history?. Evolutionary Applications, 5: 705–719. doi: 10.1111/j.1752-4571.2012.00247.x
- Issue published online: 30 OCT 2012
- Article first published online: 28 FEB 2012
- Received: 30 December 2011 Accepted: 9 January 2012
- artificial propagation;
- assignment test;
- hatchery management;
- microsatellite DNA;
- Oncorhynchus mykiss
Two strategies have been proposed to avoid negative genetic effects of artificially propagated individuals on wild populations: (i) integration of wild and captive populations to minimize domestication selection and (ii) segregation of released individuals from the wild population to minimize interbreeding. We tested the efficacy of the strategy of segregation by divergent life history in a steelhead trout, Oncorhynchus mykiss, system, where hatchery fish were selected to spawn months earlier than the indigenous wild population. The proportion of wild ancestry smolts and adults declined by 10–20% over the three generations since the hatchery program began. Up to 80% of the naturally produced steelhead in any given year were hatchery/wild hybrids. Regression model selection analysis showed that the proportion of hatchery ancestry smolts was lower in years when stream discharge was high, suggesting a negative effect of flow on reproductive success of early-spawning hatchery fish. Furthermore, proportions of hybrid smolts and adults were higher in years when the number of naturally spawning hatchery-produced adults was higher. Divergent life history failed to prevent interbreeding when physical isolation was ineffective, an inadequacy that is likely to prevail in many other situations.