Environmental consequences of using insect meal as an ingredient in aquafeeds: A systematic view

Abstract

We retrieved data from various studies to investigate the consequences of insect meal production and insect meal-based diets with respect to their environmental impact, including global warming potential, energy use, land use, water use, acidification, eutrophication as well as to economic fish-in fish-out ratio and solid waste output production. Analysis indicated that insect meals’ production exerted positive effects on land use but was associated with greater energy use and a larger carbon footprint compared to conventional protein sources. Substitution of silkworm meal (Bombyx mori) meals for fishmeal in aquatic animal diets significantly reduced solid phosphorus waste compared to insect-free diets. In contrast, the inclusion of black soldier fly (Hermetia illucens), housefly (Musca domestica), mealworm (Tenebrio molitor) and grasshopper (Zonocerus variegatus) has led, in comparison to insect-free diet, to greater solid nitrogen waste. Reducing the proportion of fishmeal and, to a lesser extent fish oil, by various insect meals in aquatic diet formulations significantly reduces economic fish-in fish-out, indicating less marine forage fish required per unit fish yield. The simulated data showed environmental benefit associated with land use of insect-containing aquafeeds compared to insect meal-free feeds, especially insect species of M. domestica and T. molitor. In all, this study suggested a trade-off of using insect meal as an aquafeed ingredient regarding environmental consequence. Since insect meal has excellent potential to supply protein for aquafeeds in the coming years, improvement in insect meal production systems and nutritional composition will be essential to make insect meal a sustainable aquafeed ingredient.