Feeding of wild and hatchery reared Atlantic salmon (Salmo salar L.) smolts during downstream migration
{feed: pubDate}

Abstract In general, hatchery salmonid smolts experience higher mortality during migration than wild smolts, which is suggested to be due to domestication effects and that hatchery fish lack experience of the natural environment. However, possible differences in feeding during smolt migration between hatchery and wild smolts have rarely been addressed. We compared the number of feeding smolts and stomach fullness among wild Atlantic salmon smolts, hatchery-reared smolts released as 1-year-old parr, and hatchery-reared smolts released as 2-year-old smolts during their descent to sea in River Tornionjoki. In addition, estimations of prey selection among the smolt groups were conducted. A high proportion of wild smolts and smolts stocked as parr actively fed during the smolt migration. A lower proportion of smolts stocked as smolts was feeding and their stomach fullness were much reduced in comparison with the two other groups. The study also indicated that the feeding of migrating smolts is selective rather than opportunistic. In conclusion, this study suggests that stocked 2-year-old smolts may enter sea with an inferior foraging behaviour and it is a possibility that this may contribute to the observed low post-smolt survival in the Baltic Sea.




  • Content Type Journal Article
  • Pages 1-9
  • DOI 10.1007/s10641-011-9846-7
  • Authors
    • Stefan Larsson, Umeň Marine Sciences Centre, Department of Ecology and Environmental Science, Umeň University, SE-901 87 Umeň, Sweden
    • Tommi Linnansaari, Canadian Rivers Institute and Department of Biology, University of New Brunswick, P.O. Box*4400, Fredericton, NB E3B5A3, Canada
    • Sauli Vatanen, Fish and Water Research Ltd. Mekaanikonkatu 3, FI-00810 Helsinki, Finland
    • Ignacio Serrano, Umeň Marine Sciences Centre, Department of Ecology and Environmental Science, Umeň University, SE-901 87 Umeň, Sweden
    • Ari Haikonen, Fish and Water Research Ltd. Mekaanikonkatu 3, FI-00810 Helsinki, Finland





More...