Diatoms for sustainable aquaculture: nutritional potential, cultivation strategies, and circular bioeconomy applications

Abstract

Diatoms are integral to aquatic food webs, facilitating energy transfer and driving the carbon cycle. Their high photosynthetic efficiency supports higher trophic levels, sustaining biodiversity and regulating ecosystem stability. They have gained considerable attention in the biotechnology field due to their unique biochemical composition, particularly their abundance of polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Diatoms are a sustainable, highly nutritious aquafeed alternative, offering superior nutrition, optimal cell size, and digestibility amid growing demand and limitations of conventional fishmeal and soybean-based feeds. Recent advances in large-scale diatom cultivation and bioprocessing highlight their viability for commercial aquafeed applications, offering enhanced growth performance, improved immunity, and superior fillet quality in farmed species. Furthermore, diatom-based feeds contribute to sustainable aquaculture by reducing dependence on wild fish stocks and mitigating environmental footprints. This review critically evaluates the feasibility of diatom biomass production, its biochemical advantages, and its role in advancing the aquafeed industry. Future research should focus on optimizing diatom strains for customized and tailored feed formulations, advancing biotechnological interventions to enhance biomass yields, and integrating diatoms into circular bioeconomy models for a more resilient and sustainable aquaculture sector.