Securing Long‐Chain Omega‐3 Fatty Acid Supply for Sustainable Aquaculture Development and Human Nutrition

ABSTRACT There is increasing awareness of combatting lifestyle diseases through improved nutrition and the important role that adequate intake of omega‐3 long‐chain PUFA has in promoting human health and development. Given the role and strategic importance of aquaculture in overall seafood production and in the supply of omega‐3 long‐chain PUFA to human consumers, this article reviews the possible differences between terrestrial and aquatic systems at different trophic levels in terms of long‐chain PUFA, and the importance of dietary fats and essential fatty acids, particularly omega‐3 long‐chain PUFA, in aquaculture nutrition and as human food. Given that most farmed fish and shrimp depend on dietary sources of PUFA for optimal growth and physiological well‐being, a synthetic and systematic review of available data on dietary EFA requirements in different groups of fish is made. Besides growth, dietary PUFA have physiological and metabolic roles for ensuring membrane integrity, reproduction, immunity and health. Additionally, omega‐3 long‐chain PUFA are critical for ensuring the nutritional value of aquatic foods for consumers. Thus, the review also addresses current challenges associated with the reduced use of fish oil in aquafeeds and explores strategies to maintain the nutritional value of farmed fish. These include finishing diets, selective breeding for enhanced biosynthesis and optimised feed formulations capable of supporting both aquaculture productivity and human nutritional needs. Compared to terrestrial food webs, aquatic ecosystems are unique in providing EPA and DHA through microalgae from low marine trophic levels. Exploitation of these in a judicious manner addresses the challenges of sustainability of aquaculture.