Resumen de Bioeconomic modeling of optimal harvest time in Nile tilapia (Oreochromis niloticus) considering size heterogeneity and minimum marketable size
Patricia Borrego Kim, Roger Domínguez May, Andrea G. Monroy Borrego, Mariel Gullian Klanian
Size dispersion in farmed fish has a substantial impact on production's bioeconomic performance, directly affecting net profits. This work's objective was to develop a bioeconomic model based on experimental data to identify the optimal harvest time (OHT) for Nile tilapia Oreochromis niloticus. The bioeconomic model considered four minimum marketable sizes (Mms = 350, 400, 450, and 500 g). Organisms were selected by size with different coefficients of variation (CV). Therefore, they were reared under two growth strategies: heterogeneous size (HT = 44-155 g; CV 25.5%) and homogeneous size (HM = 87-112 g; CV 5.9%). The HT system-generated tradable biomass of 99.30% in an OHT of 196 days with a net profit of USD 3,551.61 and a Mms of 350 g. However, the HM system achieved greater marketable biomass (99.53%) in less time (OHT = 181 days) with a net profit of USD 3,327.96 for the same Mms. The Mms of 500 g had the lowest net benefit in both systems. The HM strategy earned an additional 10.66% of incomes, indicating that the reduction in size dispersion positively impacted profits. The developed model provides a new perspective regarding the management of heterogeneity and size homogeneity in commercial production of Nile tilapia in intensive systems.
