Reducing environmental impacts in tambaqui aquaculture: a life cycle assessment of integrated multitrophic aquaculture with curimba

Abstract

This study evaluated the environmental impacts of the integrated multitrophic aquaculture (IMTA) of tambaqui Colossoma macropomum and curimba Prochilodus lineatus compared to tambaqui monoculture in ponds using life cycle assessment (LCA). The assessment is applied to a pilot-scale experiment conducted in 600 m² ponds. Collected data consisted of fish biomass, feed and fertilizer amounts, inlet water volume, electricity consumption, and greenhouse gas emissions, complemented by background data from databases and previous studies. The LCA followed a cradle-to-farm gate approach, quantifying nine impact categories for 1 kg of fish biomass produced. IMTA demonstrated reduced impacts across all categories, with substantial decreases in water dependence (38 %) and freshwater eutrophication (21 %). Additionally, IMTA reduced land occupation by 17 %, acidification and cumulative energy demand by 12 %, marine eutrophication by 11 %, net primary production by 10 %, and climate change impact by 9 %, compared to monoculture. Feed was the primary contributor to energy demand, net primary production, and climate change, while the rearing step (direct culture emissions) was the main contributor to acidification, water dependency, marine eutrophication, and land occupation. IMTA improved feed conversion ratio and nutrient recovery, key factors driving the reduction in environmental impacts. These results highlight IMTA system as a more sustainable alternative to conventional tambaqui monoculture.