Challenges of Microalgae Integration in Recirculating Aquaculture Systems: Bridging Potential and Practice
Year: 2026
Type: preprint
Abstract: Microalgae offer various benefits to aquaculture, serving as biofilters, immunostimulants, and nutrient‑rich feed additives that enhance water quality, growth, and disease resistance in recirculating aquaculture systems (RAS). Their ability to assimilate dissolved nutrients, capture CO 2 , oxygenate water, and proliferate rapidly without arable land or freshwater renders them environmentally attractive. In aquaculture, microalgae can partially replace conventional protein sources while providing omega-3 and omega-6 polyunsaturated fatty acids (PUFAs), reducing dependence on conventional feeds. Despite variability in biochemical composition and high production costs, incorporating microalgae into formulated feeds and in situ cultivation for direct grazing have been widely investigated. Recent advances in cultivation, nutrient recovery, reactor design, and techno-economic assessment have renewed interest in integrating microalgae into RAS. However, existing reviews focus on wastewater treatment, biomass production, or aquafeeds, rather than assessing the feasibility, economic viability, and scalability of in situ cultivation in commercial RAS. This review therefore evaluates current evidence on integrating live microalgae into aquaculture and RAS from technical, economic, and sustainability perspectives. Microalgae simultaneously enhance nutrient recovery, reduce aeration requirements, generate valuable biomass, and support animal health; however, evidence remains largely limited to pilot-scale studies. High light and energy demands, self-shading, and biofouling limit the photosynthetic efficiency of microalgae. Costly harvesting processes, instability among microalgal species, and water clarity management constrain consistent biomass production and scalability. Without advances in continuous, efficient harvesting, strain robustness, microbial control, and process economics, commercial adoption in RAS is likely to remain limited to niche applications rather than becoming a broadly viable strategy.
Source: Research Square
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7204163122