As the aquaculture of fed species advances, the demand for lipids rich in omega-3 fatty acids, such as EPA and DHA, is becoming an increasingly limited and strategic resource. Given this situation, experts from the Institute of Aquaculture at the University of Stirling, UK, emphasise that it is crucial to develop and manage these essential nutrient sources more effectively.
Long-chain fatty acids, such as EPA and DHA, play critical roles in fish physiology, including cell membrane structure, inflammation regulation, disease resistance, immune function, reproduction, bone formation, and stress response.
Although some fish, such as salmonids, can synthesise EPA and DHA endogenously, their performance is significantly better when these fatty acids are provided through the diet. In many marine species, the ability to synthesise these fatty acids is limited, necessitating their direct inclusion in the diet.
In their study, led by Brett D. Glencross, the researchers conducted an exploratory analysis based on insights gained from a technical workshop held in Stirling in May 2023. The results and conclusions of this analysis have been published in the journal Reviews of Fisheries Science and Aquaculture.
The study highlights the importance of optimising the use of fish oil, improving nutrient recovery from by-products, and exploring new alternative sources, such as microalgal oils and genetically modified crops. Although the global production of EPA and DHA mainly comes from fishery and aquaculture resources, the growth of these sources is limited. It is estimated that global fish oil production is around 1.2 million tonnes per year, with a significant increase in the contribution from by-products of various fisheries and aquaculture.
Additionally, the experts stress the importance of optimising resource use, as approximately 50% of omega-3 fatty acids are wasted. This underscores the need for more efficient management to recover nutrients like EPA and DHA from fishery and aquaculture by-products.
The study also highlights the development of other potential sources of these fatty acids, including those produced from zooplankton, algae, and genetically modified plants. However, to date, only algal oils have made a significant contribution, with an estimated 12,000 tonnes in 2023.
Finally, the study emphasises that many aspects of the physiological roles of omega-3 LC-PUFA in aquaculture species and the precise definition of their needs are still unknown, particularly in the context of changing dietary formulation strategies. Further research is needed to better understand the complex interactions between different types of polyunsaturated fatty acids and their effects on the health and performance of aquaculture species.
Reference:
Brett D. Glencross, Enrico Bachis, Monica B. Betancor, Philip Calder, Nina Liland, Richard Newton & Bente Ruyter (01 Sep 2024): Omega-3 Futures in Aquaculture: Exploring the Supply and Demands for Long-Chain Omega-3 Essential Fatty Acids by Aquaculture Species, Reviews in Fisheries Science & Aquaculture. DOI: 10.1080/23308249.2024.2388563
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