Evaluating the use of seafood processors' waste for the rearing of Black Soldier Fly larvae

The progressive culture of environmental sustainability demands manufacturers to minimize their negative social and environmental impact but provides an inadequate framework for innovative solutions to waste issues. Processing waste from shrimp and crab operations often exceeds 40–70% of raw material weight. Current trends of waste disposal to landfills not only pollute coastal ecosystems but also cost processors significant amounts of money. This feasibility study evaluates the potential of the Black Soldier Fly larva (BSFL)-based bioconversion system, which allows the valorization of seafood processing waste into protein-rich animal feed and agricultural fertilizer. A comparison was made between a control diet (100% commercial insect feed) to eight experimental diets in which 25%, 40%, 50%, or 60% of the commercial feed was replaced with either shrimp shell or crab shell waste. Nutrient analysis of seafood shells confirmed their suitability for BSFL rearing. Larval crude protein remained around 45% (on a dry matter basis) across all treatment diets, including higher shrimp/crab inclusion groups. Feed Conversion Ratio (FCR) and waste reduction index (WRI) improved significantly with the increase in shell inclusions in the larval diets with the highest benefits seen at 50% and 60% inclusion levels. Phosphorus levels in frass were found to be significantly higher across all the treatment diets in comparison to the control. Comprehensive economic analysis and further research on the efficacy and safety of the resulting byproducts are recommended before commercial implementation of this strategy. • Black Soldier Fly larvae consuming up to 40% shrimp or 25% crab shell showed control-level growth. • Larval crude protein remained high across all seafood-based diet treatments. • Feed conversion and waste reduction improved with higher shell inclusion (up to 60%) • Frass from shell-based diets showed increased phosphorus content supporting fertilizer amendment potential. • Nitrogen, phosphorus, and potassium were efficiently recycled from waste into larval biomass and frass.