Assessing changes in aquaculture productivity and inclusion among smallholder households attributed to project interventions

Smallholder aquaculture is increasingly promoted as a pathway for improving rural livelihoods, food security, and nutrition in sub-Saharan Africa, yet rigorous evidence on the attributable impacts of integrated aquaculture interventions remains limited. This study assesses changes in aquaculture productivity and social inclusion among smallholder households and evaluates the extent to which these changes can be attributed to project interventions under the Advancing Resilient and Nutrition-Sensitive Smallholder Aquaculture (ARNSA) initiative in Kenya. A quasi-experimental design combining baseline (n = 109) and endline (n = 187) household surveys with treatment–control comparisons and qualitative insights was employed. Results show substantial improvements in aquaculture outcomes, with 87.7% of farmers reporting increased production and beneficiary households significantly more likely to report gains than non-beneficiaries. However, attribution analysis using independent samples t-tests reveals no statistically significant differences in total harvest quantities between treatment and control groups, suggesting that productivity gains may require longer time horizons to fully materialize. In contrast, significant differences were observed in quantities of fish sold (kg: p = 0.015; pieces: p = 0.039), indicating strong improvements in commercialization among beneficiary households. Median aquaculture income more than doubled from KES 6,375 to KES 15,000, reflecting enhanced conversion of production into income. Inclusion outcomes improved, with women comprising 51% of participants and demonstrating increased decision-making roles, while youth participation rose from 16.5% to 23.0%, though remaining below programme targets. Improvements in dietary diversity further highlight nutrition-sensitive impacts. Overall, findings demonstrate that integrated aquaculture interventions can drive early gains through market-oriented pathways, with productivity effects likely to emerge over longer production cycles.