Black Soldier Fly Larvae as a Low-Cost, Climate-Resilient Protein Substitute in Lake Victoria Tilapia Feeds

Objective: Lake Victoria’s aquaculture sector is heavily constrained by the rising costs and climate vulnerability of wild-caught fishmeal (Rastrineobola argentea), which threatens regional food security. This study evaluates the biological efficiency and economic viability of using Black Soldier Fly Larvae (Hermetia illucens, BSFL) meal as a climate-resilient, circular-economy protein substitute in formulations for Nile Tilapia (Oreochromis niloticus).

Methodology: A 90-day feeding trial was conducted at a KMFRI-aligned facility on Lake Victoria. Nile Tilapia fingerlings were fed four isonitrogenous and isocaloric diets substituting commercial fishmeal with BSFL meal at inclusion levels of 0% (control), 25%, 50%, and 75%. Environmental life-cycle assessments were conducted to measure carbon-footprint reductions. Concurrently, a financial matrix evaluated feed formulation costs against local organic waste streams used to rear the larvae.

Results: Tilapia fed up to 50% BSFL meal showed no statistical difference in Specific Growth Rate (SGR) or Feed Conversion Ratio (FCR) compared to the control group. Crucially, scaling BSFL production using local agricultural waste reduced total feed production costs by 28%. From a climate-resilience perspective, shifting to insect-based protein lowered greenhouse gas emissions by 38% compared to traditional fishmeal supply chains, while mitigating the overexploitation of Lake Victoria's wild R. argentea stocks.

Conclusion: Black Soldier Fly Larvae meal provides a highly scalable, climate-smart alternative to vulnerable wild fishmeal in freshwater aquaculture. This circular-economy model decouples local tilapia production from volatile ecosystem shocks. It provides KMFRI, county governments, and private feed millers with a practical, low-cost roadmap to enhance aquaculture biosecurity, lower production overheads, and build equitable blue-food systems across the Lake Victoria basin.