Arable advances offer sustainability for aquaculture, say scientists
A collaborative approach with the agriculture sector – specifically around plant biotechnology – is key to the sustainability of aquaculture, a multidisciplinary team of scientists has said.
Integration between the sectors can provide sustainable food production solutions – for example, using genetically modified (GM) crops to meet the nutritional demands of fish and expanding growth of global aquaculture.
The innovative approach is outlined in a new paper – published in Nature Foods journal – authored by Dr Mónica Betancor and Professor Douglas Tocher of Stirling University’s Institute of Aquaculture (IoA); Professor Johnathan Napier and Dr Richard Haslam of Rothamsted Research in Hertfordshire; and Professor Rolf Erik Olsen (University of Trondheim). The paper follows a series of collaborative studies conducted by the institutions looking at the impact of using new feed solutions for Atlantic farmed salmon.
Nutritional profile
Betancor, a fish nutritionist, said: “Terrestrial animal protein production systems are inefficient to feed the world’s growing global population; they impact land use and exacerbate climate change. Fish are recognised as the only animal protein source recommended for increased production and consumption and they are also the principal source of health-promoting omega-3 long-chain polyunsaturated fatty acids.
“However, fish feeds are also becoming more plant-based and this impacts the nutritional profile of farmed fish. Plant biotechnology could offer a greener, sustainable future for aquaculture by providing beneficial omega-3 for fish and, in turn, boost levels in the human diet.
“A collaborative approach between aquaculture and agriculture can help promote the growth of aquaculture in a sustainable manner and within planetary boundaries.”
Radical transformation
Napier, an honorary professor of the IoA, said: “Agriculture and plant biotechnology has the potential to radically transform aquaculture, by providing new sources of important nutrients such as omega-3 fish oils in a manner that is not constrained by limited natural resources.
“The scalability of agriculture also means that supply can much better meet demand, helping aquaculture to further expand – but without compromising either the environment or the nutritional quality of the fish. We are proposing a more synergistic relationship between agriculture and aquaculture that will ultimately help us meet the recommendations of the EAT-Lancet report and the sustainable provisioning of the proposed ‘Planetary Health’ plate.”
Marine ingredients
Aquaculture feeds are historically based on fishmeal and fish oil from wild capture marine fisheries, but limited supply means these sources are no longer adequate to support the global expansion of aquaculture. While terrestrial animal by-products – such as poultry meal, blood meal and tallow – have been used in some parts of the world, primary alternative ingredients have been derived from plant seed meals and vegetable oils.
As the nutrient composition of farmed fish is altered, there are also consequences for human nutrition – including reductions in minerals, such as iodine and selenium; vitamins, such as vitamin D; and most significantly in the beneficial omega-3 fatty acids.
One approach uses a genetically modified strain of the oil-seed crop camelina to produce omega-3 and high-quality protein. Funded by the Biotechnology and Biological Sciences Research Council, the research team at Rothamsted has conducted a number of studies in recent years, specifically considering the viability and impact of using oils from GM oilseed crops in fish feed in providing the omega-3 long chain polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Planetary boundaries
Napier, a plant scientist, and his team are pioneering the development of GM plant-based ingredients EPA and DHA for aquafeed, while the IoA’s fish nutritionists examine the impact of the innovative feed on fish, and consider its potential benefits to human health.
The new paper concludes: “Ultimately, the two systems – aquaculture and agriculture – need to work in tandem to meet the challenges of operating resiliently within planetary boundaries and delivering optimal nutrition for a growing population.
“It is our hope that the ideas outlined in this perspective are just the starting point for a more integrated approach to sustainable aquaculture, one in which the major role of agriculture is fully incorporated.”
Read an interview with Napier about Rothamsted’s progess in the current issue of Fish Farming Expert online magazine.
