Mitigating in-pond greenhouse gas emissions in prawn farms through integrated multitrophic aquaculture system

Achieving low-emission prawn farming requires precise quantification of in-pond greenhouse gas (GHG) emissions and strategies that reduce environmental costs without compromising productivity. Using an experimental setup, we analysed 5832 gas samples to determine the seasonal and diurnal dynamics of CO₂, CH₄, and N₂O fluxes across non-aquaculture, prawn monoculture, prawn polyculture with either carp, plant, or snail, and an integrated multi-trophic aquaculture (IMTA). Non-aquaculture ponds emitted 46.33 kg CO₂e/ha/month, whereas polyculture ponds emitted 96.16 kg CO₂e/ha/month. IMTA delivered the highest biological yields, while reducing emission intensities by 40% and 20-25% compared to monoculture and polyculture, respectively. Monoculture showed the highest food and nutritional emission intensities and the largest economic footprint. Contrarily, IMTA achieved the highest revenue with the lowest economic footprint. A generalized additive model revealed that prawn biomass accounted for 74% of total emissions, while snail and water spinach substantially mitigated fluxes through waste utilization, nutrient recycling, carbon sequestration, and oxygenation. These advantages of IMTA illustrate its potential as a low-emission aquaculture approach that reconciles profitability with environmental stewardship.