Authors: Nurhayati Br Tarigan, Msc.
Aquaculture is criticized for organic waste pollution because of the high nutrient emission in fed aquaculture. Biofloc technology has been applied to achieve intensive farming while minimizing water exchange and nutrient discharge. However, knowledge of the nutrient flows in the biofloc system is still limited. This research, conducted in collaboration between the Department of Aquaculture, IPB University, Indonesia, and Wageningen University and Research (WUR), integrates empirical data with advanced modeling techniques.<br /> This study deployed experimental data to develop a mathematical model for understanding the dynamics and flows of carbon, nitrogen, and phosphorus in a biofloc-Nile tilapia-rearing system, aiming to optimize nutrient utilization and reduce environmental impact. IPB University provided essential information and facilities during data collection. The model was subsequently developed and calibrated at WUR. Both universities have a crucial role in determining optimum strategies for improving aquaculture sustainability based on the calibrated model.<br /> Model calibration and validation were performed under a Control-diet and High-NSP-diet. The diets differed by the type of starch in which the latter contains three times higher fibrous starch. The results demonstrate the model’s capability to predict nutrient dynamics accurately and suggest actionable strategies for improving nutrient management in aquaculture systems. The behavior of carbon, nitrogen, and phosphorus dynamics fit the observations with a root mean square error of less than 30% of the corresponding average observations. The High-NSP-diet resulted in more organic waste than the Control-diet. However, the amount of carbon and phosphorus loss were similar, mainly caused by the ability of biofloc to assimilate more waste in the High-NSP-diet.<br /> The collaborative effort contributes to Sustainable Development Goals 2 (Zero Hunger) and 14 (Life Below Water) by promoting sustainable aquaculture practices. The findings highlight the potential of mathematical modeling as a tool for optimizing nutrient use, thereby supporting the development of more sustainable aquaculture practices.<br />