British scientists have developed a GM oilseed plant, Camelina sativa or “false flax”, whose seeds contain omega-3 fatty acids normally only present in oily fish such as salmon, mackerel and herring.
The new study conducted at Rothamsted Research in Harpenden, Hertfordshire, showed that the plants were able to synthesise useful amounts of fish oil in field conditions without affecting their yield.
The next stage of the research will involve testing different strains of the crop and comparing them with conventional Camelina. It is primarily aimed at finding a plant-based sustainable food source for farmed fish. But plant-produced fish oil may also find its way into supplements and fortified foods such as margarine.
Rothamsted scientist Dr Olga Sayanova said: “We are delighted with the results of our first-year field trial.
“Finding a land-based source of feedstocks containing omega-3 fish oils has long been an urgent priority for truly sustainable aquaculture. Our results give hope that oilseed crops grown on land can contribute to improving the sustainability of the fish farming industry and the marine environment in the future.”
Omega-3 oils are important to fish farming because fish need them to stay healthy but do not naturally produce the substances themselves. They are manufactured by marine algae which are eaten by small fish and passed up the food chain.
Farmed fish consume huge quantities of fish oils either directly or in fish meal. In 2011 around 80 per cent of all the fish oil produced in the world went to fish farms.
Experts believe the sector is growing so fast that conventional sources of fish oil will in future not be sufficient to meet the demand.
The UK aquaculture industry alone is worth £2.3 billion and accounts for a quarter of all EU production of fish, molluscs and crustaceans.
Fish oils – specifically the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) – are known to protect against heart disease and may have other health benefits such as combating inflammation and promoting better brain function.
Although some plants, such as flax, produce omega-3 oils, they are of a different “short-chain” strain that do not have the same properties.
The Rothamsted scientists have manufactured synthetic genes based on those found in marine algae that are involved in the production of long-chain omega-3 fatty acids.
By inserting the genes into Camelina plants, they produced a crop capable of generating fish oils in its seeds. Only the seeds contain EPA and DHA – other parts of the plant including the stem and leaves are unaffected.