Declining levels of omega-3 in feed leading to unhealthy salmon; is GM oil the answer?
In 2000, 30% of salmon feed consisted of fish oil. In 2020, this was down to 10%.
Fish that consume salmon feed containing genetically modified canola oil get more omega-3, better pigmentation and fewer dark spots in their flesh, according to research centre Nofima.
In June 2023, the Norwegian Food Safety Authority (NFSA) approved Australian company Nuseed’s Aquaterra omega-3 oil — an oil made from genetically modified (GM) rapeseed — for use in fish feed.
The approved canola variant is a genetically altered form of common rapeseed, engineered to contain higher levels of EPA and DHA, the omega-3 fatty acids naturally produced by marine microalgae.
Bente Ruyter, a senior scientist at Nofima, has been at the forefront of research exploring how farmed salmon can achieve higher omega-3 content.
“Global production of fish oil is stable: catching more wild fish is not sustainable. Therefore, fish oil is becoming less and less available for the aquaculture industry every year as the industry grows”, said Ruyter.
In 2000, 30% of salmon feed consisted of fish oil. In 2020, this was down to 10%, noted the scientist.
“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.
Research indicates that this oil, when used in fish feed, improves salmon performance, increases omega-3 levels in the flesh, enhances pigmentation, and reduces the prevalence of dark spots. This breakthrough comes at a time when the global demand for marine omega-3 fatty acids outstrips supply, with wild fish stocks unable to sustainably meet the needs of the growing aquaculture industry.
The genetically modified canola oil presents a sustainable alternative, potentially becoming a crucial source of omega-3 for fish feed.
“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,” said Ruyter.
The research, financed by the Norwegian Seafood Research Fund (FHF) and in collaboration with the Institute of Marine Research, Nuseed, and Mowi, has undergone extensive trials in various stages of salmon life, ensuring no environmental discharge.