The Directorate of Fisheries has issued licenses to five fish farming companies for testing of large-scale production of sterile salmon under commercial conditions. Aqua Gen is in charge of egg production and is also, together with Institute of Marine Research (IMR,) responsible for the project.
Sterile salmon – a hot issue
There is currently considerable activity in research on methods for the production of sterile salmon, but at this time triploidization is the only method available. Triploid salmon have three sets of chromosomes instead of the two that are in diploid salmon. This state is achieved by exposing the eggs to high hydrostatic pressure for a short period approximately half an hour after fertilization. It is important to document how the triploid salmon that are produced will perform under commercial conditions and different farm environments in different parts of the country that will have varying sea water temperatures.
Performs well, but can the incidence of deformities be reduced?
Recent research has shown that triploid salmon can grow just as well or better than the diploid salmon in freshwater and the first phase in seawater, but that growth will be somewhat reduced in the time leading up to harvest size. The most negative aspect of triploid salmon has been greater incidence of skeletal deformities and cataracts. New research has shown that this problem can be reduced significantly by feeding a diet that contains sufficient amounts of available phosphorus and histidine, respectively.
Why sterile salmon?
There are several reasons for the use of sterile salmon, the most important of these is the reduction of potentially adverse effects of escaped salmon interacting with wild stocks in rivers. The salmon industry would therefore like to test sterile triploid salmon to determine if this is a viable production method based on biological, economic and animal welfare considerations.
Research licenses issued to five companies
Five fish farming companies, Eide Fjordbruk AS, Midt-Norsk Havbruk AS, Mainstream Norway AS, Nova Sea AS and Nordlaks Oppdrett AS, have therefore been given approval for research permits that will allow them to carry out commercial scale testing.
S0+ and S1+ smolts will be released in three consecutive years from autumn 2013 until spring 2016. The eggs from each brood fish are divided in two batches, one of these is put through the triploidization process and the other is produced as normal diploid. The research permits are valid for triploid production only, not for the diploid control groups. The fish must be monitored throughout production with respect to growth, mortality, incidence of deformities, etc.
The results of the project will be widely available. In addition to annual reporting to the Directorate of Fisheries, relevant results will be communicated onwww.aquagen.no, in information letters and in other ways.