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The quest for omega-3

Copyright: BBSRC

The oceans are under relentless pressure as the world population grows and we increasingly look to fish as an important food supply. Alongside this is our increasing reliance on fish to provide us with omega-3, a polyunsaturated fatty acid that our bodies need to function.

Douglas Tocher, Johnathan and Monica Betancor

Douglas Tocher, Monica Betancor and Johnathan Napier. Copyright: BBSRC

This explains the quest to find a sustainable source of fish oils.

Omega-3 is good for our joints, brain and especially our heart. The most important types of omega-3 are found almost exclusively in fish and seafood, although other types of omega-3 are found in plant products like vegetable oils and nuts. In places like Japan and Iceland, where oily fish is much more part of the staple diet people are much less prone to illnesses like heart disease and rheumatoid arthritis.

The unlikely solution to finding a sustainable source of fish oils could come from a plant called Camelina, commonly known as false flax. It’s a hardy plant that grows well in both cold and arid climate. Historically, Camelina has been grown in Europe for many centuries as an oilseed crop for lighting and more recently in North America as an industrial crop to make aviation fuel

Johnathan Napier, a leading pioneer in plant biotechnology based at Rothamsted Research has carried out field trials in the UK to create plants that can provide a sustainable source of fish oils. The crops have been genetically modified (GM) enabling them to produce these particular omega-3 fatty acids in their seed oil. Something no other plant can do.

New trial feed for salmon

Professor Johnathan Napier and leading fish nutritionist, Professor Douglas Tocher from University of Stirling, have been collaborating for nearly 20 years on finding a sustainable solution to deliver novel sources of omega-3 fatty acids.

The site where the trials will take place

The site where the trials will take place. Copyright: BBSRC

Now, together they are embarking on a new aqua feed trial delivering an alternative fish feed solution, using a genetically modified oil ingredient, to Atlantic farmed salmon which they hope will relieve pressure on stressed marine resources.

Walking around the site where the trial will take place it is clear Professor Napier is enthusiastic about the latest stage in this ongoing research using the Camelina plant, “This is the largest feeding trial to validate the efficacy of the project. It’s extremely significant because it will demonstrate the ability to use omega-3 fish oils from plants across the whole production cycle of salmon, and as a total, drop-in replacement for marine-derived fish oils.”

GM fish - I think not!

Professor Napier makes clear the fish in this project are not genetically modified, rather that, as part of their diet, they are being fed a novel ingredient derived from a genetically modified organism. The project will both serve as a proof of concept and a potential solution to the sustainability issue in supplying fish oils to farmed fish.

The young fish have already been added to the pens in which they will be fed and monitored during the course of the trial. The pens are outside in sea water and are being fed and monitored by a team of experts. Nearby there are salmon that will be fed normal fish feed so that the two can be compared. Walking around the pens that have been prepared for the trial Professor Napier is joined by Professor Douglas Tocher from University of Stirling.

Camelina plant

Camelina plant. Copyright: Rothamsted Research

Professor Tocher explains about how the trial will work, “The joint project allows us to grow salmon to market size in sea pens while extracting data to confirm that the GM oils support good growth, feed utilisation and product quality.”

During the course of the trial, Dr Monica Betancor, a Research Fellow at University of Stirling, plays a crucial role by checking on the salmons’ health and collecting data, “Collecting samples and analysing the data are imperative to the project. To test the performance of the fish, I’ll be measuring the weight and growth of the fish, but also looking at tissue and molecular samples comparing results of fish fed the GM Camelina fish feed to salmon fed the normal diet.”

Labour of love

Professor Napier has long been exploring how to develop a sustainable source of omega-3 through the use of transgenic plants with several successful field trials in genetically modified oilseed crops specifically in a flowering plant called Camelina.

They have isolated the genes in marine micro-organisms responsible for biosynthesis of omega-3; identified a plant host and produced genetically modified (GM) crops in experimental field trials at Rothamsted Research. The modified Camelina has high-levels of the beneficial omega-3 fatty acids, proving to be a safe and cost-effective source of these for aquaculture feeds.

Its taken a decade to develop plants able to produce the oils and be tested in aquaculture systems,” said Professor Napier.

Camelina plant

Camelina plant. Copyright: Rothamsted Research

The almighty omega-3 fatty acids

Omega-3 fish oils, also known as omega-3 long chain polyunsaturated fatty acids such as EPA and DHA, have been proven as beneficial to human health, reducing the risk of cardiovascular disease and other metabolic diseases such as obesity and type-2 diabetes. These oils are credited as being crucial for optimal human nutrition, but the wild fish stocks which provide them are at maximum levels of managed sustainability. Meaning the current world fish stocks are simply not able to provide enough nutrition for a growing global population.

A portion of farmed salmon today has about half the level of the Omega-3 fatty acids, EPA and DHA, compared to ten years ago,” advises Professor Tocher.

Sustainability and beyond

Both professors are determined to return levels of omega-3 fatty oils in farmed fish to levels of a decade ago, and agree consumers should expect the purchased product to have sufficient amounts of healthy omega-3 fish oils. Professor Napier is keen to stress that the results of the trial should complement and not replace existing aquaculture activities, “This GM technology shows great promise as a potential solution to help fish farming become more sustainable and continue growing as an industry.” He added “What we really want is to ensure that every person on our planet gets the omega-3s they need - and using our GM Camelina, we can take pressure of the oceans whilst delivering better nutrition from the land.”

Video

You can read more about the project to provide highly nutritious omega-3 fatty acids from Camelina at Rothamsted Research: From oceans to fields and back again.