Stocking experiment with Atlantic salmon and sea trout parr reared on either live prey or a pellet diet

Abstract

Survival rate and growth parameters of Atlantic salmon fry and sea trout fry were determined after stocking in the wild. Before release (22 May 2009) into the wild the larvae were reared for 10 weeks in the hatchery in three groups: (i) fry fed on live zooplankton, (ii) fry fed on larvae of live nekton, and (iii) fry fed on prepared pellet food. In autumn (15 September 2010) the fish were caught in the wild; the survival rate and growth parameters of both Atlantic salmon and sea trout were the highest in the zooplankton-fed group, whilst the pellet-fed group had the lowest survival rate and growth value parameters. Most effective food for hatchery-reared fishes to be used as stock was the natural living zooplankton. The general conclusion is that the live diet supplied in the rearing period has a positively impact on fish survival in the wild.