Modelling growth and biomass of Oreochromis mossambicus in a periphyton-based aquaculture production system using secondary data

This study was conducted to potentially optimize the sustainable culture of Mozambique tilapia (Oreochromis mossambicus) in a periphyton-based aquaculture system with supplemental feeding to aqua dams using stochastic simulation models. This was achieved by firstly determining tilapia growth and biomass using nonlinear (von Bertalanffy, Logistic, and Gompertz) growth function models per substrate (net, plastic and stone). The parameters were extracted from the Logistic growth model since it had a better fit and were subsequently used in the Monte Carlo simulation for both tilapia growth and biomass models per substrate. The mean absolute error and root mean square error values for both the tilapia growth and biomass models showed that the models were a good fit. The simulated tilapia growth model showed that tilapia weight can exceed 800 g in 12 months in tanks with a net and plastic substrate. The model also showed that 70 kg/m2 can be achieved in 6 months in tanks with a plastic substrate. The first-order stochastic dominance confirmed that the plastic substrate enhanced tilapia growth and biomass. Sensitivity analysis showed that tilapia growth and biomass were most affected by temperature, total phosphate, total nitrogen and periphyton abundance. The model showed that periphyton-based aquaculture has great potential.