Insect Meal in Aquaculture Feeds-Historical Development, Current Applications, and Future Perspectives

In 2022, global aquaculture production reached nearly 130.9 million tons, which for the first time ever exceeded capture fisheries production, because of which additional concerns were raised about the industry's reliance on unsustainable sources of fishmeal. Insect meals, which have emerged with a strong potential as sustainable replacers partially due to their high crude protein, amino acid balance, and variety of bioactive components (e.g. chitin, lauric acid, and antimicrobial peptides), are among the possible alternatives. Feeding trials using insect meal in diets for fish and shrimp (e.g. salmon, tilapia, and shrimp), have shown improvements in growth performance, gut integrity, and immune markers; some trials even completely replaced fishmeal with dietary insect meal with no subsequent loss in overall performance. Furthermore, using insect meal produced from agricultural by-products fits under the circular economy umbrella, which addresses land and water use, and alleviates pressure on marine ecosystems, while also providing additional nutrients and proteins in aquaculture diets. However, high production costs (USD 3,800- 6,000/ton), the risk of heavy metal or chemical residue contamination based on rearing substrate, and regulatory inconsistencies are currently common limiting factors. The European Union's regulation authorizing some insect species in aquatic animal feed (EU 2017/893) has been a significant milestone in this field. This review addresses the historical development of insect meals in aquatic diets, their nutritional benefits, application results, economic limitations, and environmental impacts as well as discussing opportunities and challenges for more widespread use. Consequently, future studies are recommended to focus on quantitative assessment of the effect on the nutritional profile of the cultivation substrate and the optimization of species/age-specific formulations.