News & Views Fish Nutrition Research
Nofima investigates genetically modified canola oil as source for fish feed

Omega-3 fatty acids demand is greater than supply. To that end, Nofima scientist Bente Ruyter conducted research to find out how farmed salmon can get a higher content of omega-3 in the body. One option is oil from modified canola, a variant of common rapeseed.

The canola that provides the oil researched by Nofima has been genetically modified and developed by the Australian research organization Commonwealth Scientific and Industrial Research Organisation (CSIRO) in collaboration with the company Nuseed. As a result, it contains more of the omega-3 fatty acids that salmon need to stay healthy, and that humans benefit from.

“The Norwegian Food Safety Authority has approved a genetically modified canola oil that can be used in salmon feed. The plant produces marine omega-3 fatty acids. Many years of research together with the industry has brought us to this point,” said Ruyter.

Marine microalgae produce these fatty acids, EPA and DHA, crustaceans eat these microalgae, and the fish eat the crustaceans. Therefore, EPA and DHA end up in the fish. Since it’s been challenging to get high enough levels of these fatty acids in farmed salmon, microalgae genes have been inserted into canola so that it can also make the same fatty acids. 

When the oil is used in fish feed, the scientists have found that the fish perform better, get more omega-3, fewer dark spots and better red colour in the fillet.

In 2000, 30 per cent of salmon feed consisted of fish oil, in 2020, it was down to 10 per cent.

“Our research shows that it is not healthy for salmon to have such low levels of omega-3 in the feed. They become less robust and their flesh has poorer colour. The industry has therefore started to increase the level of omega-3 fatty acids in the feed again,” she said. “The production of genetically modified canola has great potential for growth, and will probably become an important new source of omega-3 in the fish feed.”

To document the properties of the oil in salmon, scientists conducted trials in fresh water, in closed tanks and finally in net pens.

“It is now approved for use. Whether the industry uses it is another matter. But I think it will force its way in,” said Ruyter.

The research has been financed by the Norwegians Seafood Research Fund (FHF) and went in collaboration with the Institute of Marine Research, Nuseed and Mowi.