This study aimed to quantify inputs, outputs and accumulation of nitrogen in integrated multi-trophic aquaculture (IMTA) and monoculture systems of phase II sunshine bass (Morone saxatilis ♂ x Morone chrysops ♀) and giant river prawns (Macrobranchium rosebergii) farmed in stagnant earthen ponds. The experimental design was completely randomized with three replications of four treatments. The factor tested was the type of production system with four levels: Fish monoculture (FM) with 2 ind/m², Prawn monoculture (PM) with 1 ind/m², Fish-prawn IMTA (IMTA-FREE) with the fish and prawns free-swimming at 2 ind/m² and 1 ind/m², respectively, and fish-prawn polyculture (POLY-CAGE) with the bass reared in cages at 390 ind/cage and the prawns free-swimming at 1 ind/m². Samples of inputs of stocked animals, inlet water, rain, feed, and atmospheric gas and the outputs of harvested animals, total suspended solids, accumulated sludge, settleable solids, harvest water, and gas emissions were collected and analyzed to calculate the nitrogen budget.
The duration of the experiment was 82 days from June 24, 2025, to September 17, 2025, and nitrogen samples are still being analyzed. The stocking and harvest periods were atypical of the recommended dates for these two species because of unseasonably cold weather in the late spring and late-mid summer. Table 1 shows the dissolved nitrogen parameters of the water quality. No significant differences were observed between treatments. The nitrite was at an acceptable level, which indicates that the dissolved oxygen was sufficient to convert ammonia from animal waste into harmless nitrate.