| Publication Type: | Journal Article |
| Year of Publication: | 2011 |
| Authors: | L. J. Roberts, Taylor, J., C. de Leaniz, G. |
| Journal: | Biological ConservationBiological Conservation |
| Volume: | 144 |
| Pagination: | 1972-1979 |
| ISBN Number: | 00063207 |
| Keywords: | Anti-predatory behavior, Boldness, Captive-breeding, Environmental enrichment, Maladaptation, Salmonid conservation |
| Abstract: | Hatcheries often produce bold fish that are maladapted to survive in the wild, as absence of predators andselection for fast growth tend to favour risk-taking behaviors. Not surprisingly, losses of hatchery fishthrough predation can be high immediately after release and this may account for the failure of manyex-situ fish conservation programmes. For supportive-breeding to be useful, it is essential that releasedfish are able to display natural behaviors. We compared the performance of juvenile Atlantic salmonreared in environmentally-enriched tanks receiving natural prey and subjected to simulated predatorattacks with fish reared under standard hatchery conditions while keeping densities constant. No differenceswere detected between controls and environmentally enriched fish in survival, final size or nutritionalstatus. Yet, changes in rearing conditions had rapid and marked effects on risk-taking behavior.Environmentally enriched fish were 2.1 times less willing, and took significantly longer to leave shelter,than controls within two weeks of enrichment. Thus our study indicates that it is possible through environmentalenrichment to modify at least one component of fishes’ behavior known to have clear adaptiveimplications, i.e. the propensity of hatchery-reared fish to take excessive risks. Ex-situ conservation couldtherefore benefit from rearing fish in naturalized, structurally complex environments with natural prey topromote the development of more natural behaviors. |