This study evaluates the potential of low-input fish farming integration to enhance productivity and livelihoods in the mangrove rice systems of Maritime Guinea. Building on a co-design approach implemented during 2020–2023, agronomists and farmers collaboratively tested a set of five simple aquaculture practices: selecting plots with pH > 5.5, maintaining higher water depth, conducting a single final harvest, stocking tilapia Sarotherodon melanotheron as main raised species and introducing predatory Hemichromis fasciatus . A total of 30 on-farm trials were conducted and compared to 10 baseline plots without intervention. Measurements included fish biomass, tilapia yield, rice production, income, and environmental parameters (pH, salinity, dissolved oxygen). Data were analysed using ANOVA, Pearson correlations, and PCA. Results show a fourfold increase in fish production (from 85,4 to 341,9 kg/ha) without compromising rice yields. This intensification was primarily driven by higher stocking densities and improved environmental conditions, particularly higher pH. Increased fish biomass translated into higher household income, mainly through self-consumption, with total plot income rising from 2.5 to 6,4 €/are. However, trade-offs emerged between total biomass and individual fish size, with implications for market value. The role of predator fish H. fasciatus remained secondary, with limited influence on overall yields. The results show that low-cost zootechnical adjustments, developed in collaboration with farmers, can significantly improve the performance of rice-growing systems in resource-constrained mangrove environments. Beyond incremental gains, these findings point to a form of disruptive innovation, as they redefine the productive logic of traditional, subsistence-oriented rice farming systems by integrating aquaculture without requiring capital-intensive inputs. By leveraging locally available resources, ecological processes, and farmers’ knowledge, this approach challenges dominant intensification models and opens new avenues for value creation in marginal environments. However, the transferability and long-term sustainability of such a disruptive trajectory remain contingent on market access and the ability to sustain adaptive and participatory innovation processes over time.
Fertin et al. (Sat,) studied this question.