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14 June 2022 - for immediate release

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Key publications, presentations and reports related to SSA's key themes

Leading UK scientists regret ScotGov’s stance on gene editing

Two of Britain’s most eminent scientists have expressed their disappointment that precision breeding techniques such as gene editing have become a ‘political football’ in a stand-off between Holyrood and Westminster, highlighting key opportunities to use these technologies to improve the quality and sustainability of Scotland’s top food export – farmed salmon

According to Professor Johnathan Napier, a plant scientist at Rothamsted Research in Hertfordshire, Scottish aquaculture is a booming sector of the economy, but sustainability challenges are on the horizon.  


“Scotland’s £1.8bn salmon farming industry has grown into the country’s leading food exporter, with annual export sales in excess of £450m. And with ambitious plans to double output from 170k tonnes to 350k tonnes by 2030, the significance of the aquaculture sector to jobs, growth and export earnings in Scotland’s rural economy cannot be over-stated.


“A key challenge for the salmon farming industry, however, is to sustain that growth while maintaining levels of the healthy omega-3 oils known as EPA and DHA in the final product. Over a 10-year period, levels of these beneficial oils have declined by 50%. This is primarily due to sustainability concerns over marine fish stocks, which mean that while the global salmon farming industry continues to grow each year, the annual global harvest of marine fish oils has remained static at around 800k tonnes, diluting the available fish oil across a bigger pool of production.


“This in turn has encouraged a trend of replacing marine oils with vegetable oils, which naturally lack the special health-giving omega-3s found in fish oils, changing the fatty acid profile of the salmon fillet the consumer is now presented with.”

Professor Napier highlights the importance of a diet rich in omega-3s, and explains how precision breeding technologies such as gene editing can help:


“A diet rich in omega-3s is health-protective, especially for reducing the risk of cardiovascular disease (CVD). Scotland, like the rest of the UK, does not achieve the recommended levels for dietary intake of omega-3s, particularly in younger people.  And whilst thankfully Scotland no longer has the unenviable reputation for being a nation of on the verge of a heart attack, much still needs to be done to improve health conditions associated with poor nutrition, such as CVD, type-2 diabetes and obesity.


“A potential solution lies in the role of technologies such as GM and gene editing in transforming the way nutritious food is produced in Scotland. Specifically, my research has shown that oilseeds like Camelina can be engineered to accumulate omega-3 fish oils, providing a renewable, crop-based alternative to over-stretched marine resources. Successful aquafeed trials in Scotland have already demonstrated how this could help make home-grown salmon farming more sustainable and more nutritious – breaking our dependence on the oceans as a source of fish oils while restoring omega-3 levels in farmed salmon to what they were 10 years ago.    


“These new, added-value crops could also provide an alternative income stream for Scottish farmers, directly connecting agriculture and aquaculture at the national level rather than importing feed ingredients from the other side of the planet.”


Another challenge facing the sustainable growth of Scotland’s salmon farming industry is the ability to control disease outbreaks such as the viral disease Infectious Salmon Anaemia (ISA) and ectoparasitic sea lice, which can have a major negative effect on salmon production and welfare.

Livestock geneticist Professor Helen Sang explains how colleagues at the Roslin Institute in Edinburgh are using precision breeding techniques such as gene editing to help tackle these issues:    


“Conventional breeding can be used to improve disease resistance in salmon stocks but requires time as it takes place over several generations. Gene editing has the potential to accelerate the development of disease resistant salmon.


“For example, researchers at Roslin are using gene editing technology to investigate the genes underlying resistance to the ISA virus, and to increase the resistance of salmon to this disease. They are also exploring whether they can transfer the mechanisms by which some of the salmonid species are more resistant to diseases than others, particularly for sea lice.


“Given that sea lice are such a huge problem for the industry, and the plethora of prevention and control mechanisms currently used provide only limited success, gene editing offers a potentially more sustainable way to help prevent infestations through the development of genetic resistance.


“These are long-term projects, but substantial research focused these disease resistance objectives is already underway – led by scientists based in Scotland. The results could be transformational for the economics of the industry, the welfare of the salmon, and reduced dependence on veterinary medicines with related concerns about environmental impacts.”


However, following recent confirmation from Scotland’s Rural Affairs Minister Mairi McAllan that the Scottish Government has no plans to ease restrictions on gene editing – despite overwhelming scientific evidence of their safety, and as other parts of the world, including the EU, move to enable their use – both scientists have expressed their regret that these examples of UK-led research, with enormous potential benefits for more sustainable aquaculture, could fail to be realised in practice.


“Scotland is rightly proud of its reputation as a world-leading hub for agricultural and biological science, with internationally renowned centres of research excellence underpinned by a vibrant university sector. If Scotland is to maintain its reputation for global scientific leadership the position on application of new genetic technologies in agriculture needs further consideration,” said Professor Sang.


“The Scottish Government often justifies its policy stance on GM and gene editing in terms of preserving the clean, green image of Scotland’s food and drink economy. Yet these examples show how new breeding techniques can be used to enhance the sustainability of key sectors such as salmon farming,” said Professor Napier.


“We must above all ensure that scientific innovation and its ability to deliver more sustainable, healthier outcomes for society does not become the ‘collateral damage’ of entirely unrelated political disagreements.”   


Johnathan Napier and Helen Sang are both members of the Science for Sustainable Agriculture advisory group.

Professor Johnathan Napier is a leading pioneer in plant biotechnology and an advocate for the power of GM plants to deliver for the public good. At Rothamsted Research, his flagship research programme involves both GM and gene editing techniques to develop oilseed crops with enhanced Omega-3 levels as a more sustainable, plant-based source of healthy oils for human nutrition and for the aquaculture sector.


Professor Helen Sang OBE, FRSE, FRSB has led a research programme at The Roslin Institute (University of Edinburgh) on the development and applications of genetic modification technologies in the chicken. This research has included applications in basic biological research, in biotechnology and in the potential to develop genetically disease resistant chickens, with funding from Government, mainly UKRI-BBSRC and industry. 

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