Researchers in the Highlands of Scotland are giving farmed salmon feed made from genetically modified crops. The aim of the scientific trial is to increase the nutritional value of the fish. The feed is rich in healthy fish oils, which the team hope will be absorbed by the salmon. Critics argue that GM technology is “propping up” an unsustainable system of industrial food production. Tests have shown that levels of oil called omega-3 have decreased by half in farmed salmon in the past 10 years. It is what makes the fish so healthy. The oil is thought to be involved in brain development and reduces the risk of heart disease, arthritis and diabetes. Even at current levels, farmed salmon is still a rich source of omega-3 – but levels are continuing to fall. The salmon get their omega-3 from eating other oily fish, such as anchovies, that have been ground up and added to pellets that are sprayed into their pens. But there’s a limited supply of anchovies and a growing demand for the salmon. So that means that all across the world there’s less oily fish to go round to make food for salmon. Researchers have added a gene from a type of marine algae to a camelina plant to produce the omega-3 fish oil. Lab tests show that fish fed on this oil have boosted levels of omega-3. The question that the researchers are now trying to answer is whether the same happens on a real fish farm. Prof Douglas Tocher, of University of Stirling, who is leading the study, is hoping his GM produced fish food will help turn things around and make farmed salmon as good for you as it once was. “These are essential nutrients to our diet to maintain our health; particularly cardiovascular health, some inflammatory diseases and some cancers. Here in the UK, particularly up in Scotland, we suffer quite badly from many of the diseases for which dietary omega-3 has beneficial effects”.