Integrated multi-trophic aquaculture as a nature-based solution for climate resilience and livelihood improvement in Kijiweni, Kwale County, Kenya

Coastal communities in Kwale County are increasingly vulnerable to climate change impacts, including rising sea temperatures, ecosystem degradation, and declining fish stocks, all of which have intensified livelihood insecurity and reduced food availability. In this context, nature-based solutions such as Integrated Multi-Trophic Aquaculture (IMTA) offers a promising approach for enhancing eco logical sustainability while supporting socio-economic resilience. IMTA integrates species from different trophic levels, such as finfish, seaweed, and other marine resources within a shared system to promote nutrient recycling, improve water quality, and diversify production. This study assessed the effectiveness of IMTA in improving fish growth and productivity under different feeding regimes, and evaluate its role in enhancing climate resilience and sustainable livelihoods among coastal communities in Kijiweni, Kwale County. A mixed-methods approach was employed, combining experimental and participatory techniques. Fish growth performance was monitored in IMTA cages system using commercial feed and Eucheuma seaweed, while environmental parameters were measured to evaluate system efficiency. Socio-economic data were collected through community engagement, semi structured interviews, and field observations. Preliminary findings indicate IMTA systems supplemented with seaweed achieved higher fish growth rates compared to conventional systems. The integration of seaweed enhanced nutrient uptake, reducing environmental pollution while enhancing water quality. Additionally, community members, particularly women, reported increased income opportunities through seaweed farming and value addition activities. The system also demonstrated strong potential for enhancing resilience to climate variability by diversifying livelihoods and reducing dependence on capture fisheries. Overall, IMTA presents a practical and scalable nature-based solution for sustainable aquaculture, environmental management, and livelihood improvement. Its adoption in Kijiweni highlights its potential to contribute to ecosystem-based management and support Kenya’s sustainable blue economy agenda.