Scotland’s University of Stirling is using genetically modified plants to replace fish oil in fish feeds with the aim of preserving wild fish stocks and maintaining nutritional value of farmed fish for humans.
In a collaborative project with Rothamsted Research, genetically modified Camelina plants were developed to produce essential omega-3 fatty acids in their seeds, which was assessed for its suitability as fish feed.
Professor Douglas Tocher, project lead at the University of Stirling, said that the development of new novel plant oils, tailored to human requirements, represent a sustainable way to farm fish with high levels of omega-3 fish oils that maintain their high nutritional value to humans while preserving wild fish stocks.
In this project, the scientists used five microalgal and fungal genes to generate a sustainable source of omega-3 fish oils from the plants. This was then incorporated into fish feeds and Stirling scientists assessed the suitability of the feeds for Atlantic salmon.
The results, published in the journal Scientific Reports, demonstrated that growth performance, feed efficiency, fish health and nutritional quality for the human consumer were unaffected when dietary fish oil was substituted with oil from the GM plants.
Professor Tocher told World Fishing & Aquaculture: “This experiment was a stepping stone in the development of a new oil which will be structurally very similar to fish oil. Whereas this project involved making an oil with 20% omega-3 fatty acid Eicosapentaenoic acid (EPA), the new oil will contain 12% EPA and 8% Docosahexaenoic acid (DHA), much closer to fish oil and better able to be commercialised.”
The plan is to continue trialling the oils in Atlantic Salmon and Sea Bream so that the scientists can account for the difference in bio-chemistry across different species.
It has long been known that consumption of omega-3 fish oils is linked with improved human cardiovascular health and cognitive development. The primary dietary sources of these fatty acids for humans are marine fish - either wild or farmed.
But there is currently a gap between supply and demand for fish oils and new sources are required for both the aquaculture industry and for direct human consumption.
Professor Tocher said: “Fish oil is a finite and limited resource and because the aquaculture industry is constantly expanding sustainability is vital.” He pointed out that because each individual plant can produce 6000 seeds, it’s a really good way to scale up production of fish oil and fish feed on a larger scale.
