Enhanced growth and reduced fat accumulation in Nile tilapia (Oreochromis niloticus) through spirulina supplementation: a cost-benefit analysis

This study examines the effects of spirulina supplementation on the growth, fat accumulation, and economic viability of Nile tilapia in aquaculture. Conducted in two phases, the first trial took place at the Costa Rican Institute of Fisheries and Aquaculture (INCOPESCA) and the second on a farm in Buenos Aires, Puntarenas, Costa Rica. Diets included 9 % to 25 % spirulina replacing the basal feed. Outdoor growth was modeled using the Pearl growth curve, and feed conversion ratios (FCR) were assessed for efficiency. Mineral content, protein efficiency ratios, and lipid profiles were analyzed using standard methods. A 9 % spirulina substitution accelerated tilapia growth, reducing the marketable weight time by 1.9 months. Spirulina-fed fish had less fat content compared to the control group. Although feed costs increased slightly with spirulina, savings in time and labor led to a net economic benefit of about $220 USD per 100 fish. The operational savings and improved production efficiency justified the additional spirulina cost, demonstrating its economic viability. These findings suggest spirulina supplementation as a beneficial practice for aquaculture producers, offering both economic and nutritional advantages.