Biofloc technology toward sustainable aquaculture: Opportunities, constraints and environmental perspectives

The growing demand for fish protein has intensified aquaculture practices, heightening concerns about nutrient accumulation, water pollution, and disease outbreaks. Biofloc technology (BFT) has emerged as an innovative approach with the potential to transform aquaculture by promoting in situ nutrient recycling, reducing water exchange, and enhancing resource use efficiency. This systematic review protocol was developed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, and the screening process was conducted using the Rayyan QCRI tool. This review findings highlight evidence that BFT can substantially reduce feed input costs by up to 30 % through microbial protein utilization, stabilize water quality, and strengthen fish health via probiotic and immunostimulatory mechanisms. Its relatively low capital investment requirements also make it accessible to smallholder farmers, offering opportunities for inclusive growth in resource-limited regions. Nevertheless, the universal application of BFT remains constrained by significant limitations such as high energy demand for aeration, unstable power supplies, limited technical expertise, and challenges in water management, especially in developing countries. These shortcomings restrict BFT's ability to consistently deliver sustainable outcomes across diverse production contexts. To unlock its full potential, targeted interventions are required. Research and development should prioritize energy-efficient aeration systems, low-cost renewable energy integration, and optimized carbon source management to reduce operational costs. Capacity building and policy support are equally essential to ensure responsible implementation while safeguarding environmental safety. This review concludes that BFT holds strong potential to modernize aquaculture without compromising environmental safety. It can do so by improving nutrient recycling, reducing effluents, enhancing fish health, and lowering feed costs. However, realizing this promise depends on overcoming constraints such as energy demand, species-specific suitability, and management challenges. Future developments in energy-efficient aeration, carbon source optimization, and supportive policy frameworks will be essential to unlock its full potential.