Over a period of years, Nofima researchers and partners have developed a promising method to sterilize salmon – an outcome which means they cannot interbreed with wild salmon if they escape from farms, as well as potentially improve the quality of their meat and reduce disease and mortality rates.
There are several ways to sterilize salmon, such as triploidization and gene editing. However, triploid salmon has been rejected as an option in Norway due to welfare concerns and the use of genetically modified salmon in production is still not permitted.
The technique developed by Øivind Andersen and Helge Tveiten of Nofima – which they call “the Nofima method” – blocks a factor necessary for the development of reproductive cells at the embryonic stage, which means that the fish never become sexually mature. Except that it has small gonads that do not produce eggs or milt, sterile salmon have the same outward appearance and characteristics as fertile fish.
However, in order to further develop the Nofima method into large-scale industrial production of sterile salmon, satisfactory health and growth must also be documented.
Andersen and Tveiten have now examined important production traits in their sterile salmon throughout their lives through extensive investigations of body growth, smoltification, stress tolerance, sea lice infestation and mortality. at sea.
Sterile salmon show production characteristics at least as good as fertile farmed salmon, even in the face of a severe lice attack. Scientists have also documented that sterile salmon have no reproductive cells from their embryonic stage until the time of slaughter.
Andersen and Tveiten have now started working on different strategies for large-scale production of sterile salmon in partnership with the fish farming industry.