Synchrosmolt

Synchrosmolt: Smolt production protocols and breeding strategies for synchronized smoltification

Summary

Even though the Atlantic salmon lives in the ocean as adults, their lives start in fresh water. In the wild salmon spends about 2-5 years in the river before they undergo a physiological transformation called “smoltification”, encompassing changes in metabolism, growth, colouration, and sea water tolerance. Under natural conditions, the timing of this smolting process is regulated by both body size and environmental cues such as water temperature and daylength. Farmed fish, however, is kept under (often) highly unnatural light and temperature conditions before they are released into sea cages. A substantial (10-15%) proportion of these farmed produced smolts develop serious health problems or die. Our hypothesis is that optimizing smolt production protocols, specifically the light regime, can increase the synchronization of smolting in farmed salmon – resulting in more fish being ‘optimally’ prepared for a life in the sea. Synchrosmolt will investigate if genetic variation in the fish’s response to smoltification regimes (i.e. light) can be exploited to breed fish with more synchronised smoltification. We will test if genetic variation is associated with smolt development timing under different daylength regimes, and test novel gene expression based markers for predicting smoltification status and seawater performance.

Outcomes and impacts

This work has the potential to result in precise molecular markers which can be used to select for fish that will have a more similar (synchronous) smolt development. If the project succeed, smolt producers can produce more physiologically uniform population of smolt, which will help improve animal welfare, growth and survival of farmed salmon in the sea water phase.

CIGENE researchers involved: Simen Sandve