Microalgal Aquafeeds As Part of a Circular Bioeconomy.

Photosynthetic microalgae are unicellular plants, many of which are rich in protein, lipids, and bioactives and form an important part of the base of the natural aquatic food chain. Population growth, demand for high-quality protein, and depletion of wild fishstocks are forecast to increase aquacultural fish demand by 37% between 2016 and 2030. This review highlights the role of microalgae and recent advances that can support a sustainable 'circular' aquaculture industry. Microalgae-based feed supplements and recombinant therapeutic production offer significant opportunities to improve animal health, disease resistance, and yields. Critically, microalgae in biofloc, 'green water', nutrient remediation, and integrated multitrophic aquaculture technologies offer innovative solutions for economic and environmentally sustainable development in line with key UN Sustainability Goals.