Box 1 The pros and cons of utilizing local vs. nonlocal farmed strains
The nature of fisheries- and farming-induced evolution
Article first published online: 4 SEP 2007
© 2007 The Authors. Journal compilation © 2007 Blackwell Publishing Ltd
Volume 17, Issue 1, pages 294–313, January 2008
How to Cite
HUTCHINGS, J. A. and FRASER, D. J. (2008), The nature of fisheries- and farming-induced evolution. Molecular Ecology, 17: 294–313. doi: 10.1111/j.1365-294X.2007.03485.x
A challenge facing the mitigation of the evolutionary effects of fish farming is whether to use (i) local farmed strains derived from wild populations found in the same regions where farming takes place (e.g. ‘A’ in Fig. 2); or (ii) nonlocal strains derived from wild populations not found in the same regions where farming takes place (e.g. ‘B’ or ‘C’ in Fig. 2; see also Bekkevold et al. 2006). Arguments for using either local or nonlocal strains might proceed as follows:
• ‘Local’: local strains would be less divergent from nearby wild populations, so they would pose less severe outbreeding effects when farmed–wild interbreeding occurs than if nonlocal strains were used.
• ‘Non-local’: but in being less-divergent, local strains would have weaker differences in reproductive behaviour from wild populations, so they might be expected to successfully interbreed with wild fishes at a much higher rate than nonlocal strains. The fitness costs of farmed–wild interbreeding could therefore potentially affect more of the wild population over the short-term and occur more readily in subsequent generations.
• ‘Local’: nevertheless, reproductive behaviour in fishes is generally not fixed, and no farmed strain has been so thoroughly domesticated that it was unable to breed with wild relatives (Naylor et al. 2005). Thus, interbreeding would still occur with a nonlocal strain, and even if it did not initially affect as much of the wild population as a local strain, the fitness costs might actually be higher in the long term. For instance, new genetic variants in a more divergent, nonlocal strain could be introduced and/or be created through recombination down the generations in the wild population, and this might ultimately supplant the wild genotypes (e.g. Edmands & Timmerman 2003; Campbell et al. 2006; Johansen-Morris & Latta 2006).
• ‘Non-local’: perhaps, but in another context, implementing the use of nonlocal strains is more economically attractive since it would not require multiple breeding programmes associated with local population characteristics (i.e. one or a few chief farmed strains could be used ubiquitously).
• ‘Local’: perhaps, but the use of many local strains might maintain greater levels of genetic diversity in the species by reducing overall genetic homogenization, and thus be more likely to maintain viable wild populations and farmed strains in the long term.
- Issue published online: 4 SEP 2007
- Article first published online: 4 SEP 2007
- Received 11 March 2007; revision accepted 29 June 2007
Options for accessing this content:
- If you have access to this content through a society membership, please first log in to your society website.
- If you would like institutional access to this content, please recommend the title to your librarian.
- Login via other institutional login options http://onlinelibrary.wiley.com/login-options.
- You can purchase online access to this Article for a 24-hour period (price varies by title)
- If you already have a Wiley Online Library or Wiley InterScience user account: login above and proceed to purchase the article.
- New Users: Please register, then proceed to purchase the article.
Type your institution's name in the box below. If your institution is a Wiley customer, it will appear in the list of suggested institutions and you will be able to log in to access content. Some users may also log in directly via OpenAthens.
Please note that there are currently a number of duplicate entries in the list of institutions. We are actively working on fixing this issue and apologize for any inconvenience caused.
Registered Users please login:
- Access your saved publications, articles and searches
- Manage your email alerts, orders and subscriptions
- Change your contact information, including your password
Please register to:
- Save publications, articles and searches
- Get email alerts
- Get all the benefits mentioned below!