Resource use and environmental impacts of net cage tilapia and land-based pond catfish intensive aquaculture production systems: A life cycle assessment

Abstract

This study examines resource use efficiency and environmental impacts of net cage Nile tilapia and concrete pond African catfish aquaculture systems in Nigeria using a life cycle assessment (LCA) framework. Ten midpoint impact categories were quantified using the CML-IA Baseline 2002 method, Ecoinvent v3.4, and SimaPro v9.3, with a functional unit of one tonne of live fish at the farm gate. Our results revealed that catfish pond system operated at higher stocking density, consumed 47% more feed per tonne (eFCR: 2.42 vs. 1.65), with eight-fold higher energy demand for feed production, grow-out farm operations, and also a higher overall mass-balance nutrient discharge (114.75 vs. 62.41 kg N/t) than the tilapia net cage system. The catfish system recorded higher environmental burdens across all environmental impact categories except for marine ecotoxicity (MET), where tilapia system exceeded catfish (7050 vs. 4070 kg 1,4-DB eq/t). Feed production was the dominant environmental hotspot in both systems, contributing 35–70% across impact categories, with feed ingredients like fishmeal, and soybean, the main impact drivers. Sensitivity analysis confirmed that eFCR improvement yielded the most consistent cross-category reductions, whereas extending infrastructure lifespan from 15 to 20 years reduced human toxicity (HTP) by up to 14.3% in tilapia and abiotic depletion by up to 13.5% in catfish systems, while a national electricity grid decarbonization scenario reduced total global warming potential (GWP) by 9.6% for tilapia and 25–33% for catfish. Black soldier fly larvae meal substitution in formulated feeds reduced GWP by up to 24.7% and MET by up to 36.5% at 35% inclusion, but increased acidification and HTP by up to 27.2% and 15.4% respectively. These findings provide actionable evidence for feed formulation policy, system design, and energy investment in Nigerian aquaculture, and establish a replicable LCA framework for resource-constrained production contexts across sub-Saharan Africa.