Abstract
The rapid expansion of aquaculture in Bangladesh has played a vital role in meeting the increasing demand for fish protein. However, the industry faces significant challenges due to the high cost and environmental impact of fishmeal (FM), a primary protein source in aquafeeds. This review critically evaluates alternative protein sources for aquafeeds, including plant-based proteins, insect meals, agricultural by-products, and single-cell protein (SCP), with a focus on their applicability in the Bangladesh context. Using the Joanna Briggs Institute (JBI) methodology, we synthesized evidence from peer-reviewed studies and institutional reports to assess the nutritional profiles of these alternatives. Results show that while plant-based proteins are affordable and locally available, they require processing to reduce antinutritional factors (ANFs). Insect meals exhibit high protein content and feed efficiency, with a primary focus on their essential amino acids (EAAs) profiles, which are crucial for optimal fish growth, immunity, and metabolic performance. Agricultural wastes such as fruit peels and vegetable residues offer cost-effective and immune-boosting properties, while SCP derived from algae, fungi, yeast, and bacteria emerge as a nutritionally robust and environmentally sustainable option. Despite the promise of these alternatives, limitations persist in terms of nutrient imbalances, processing requirements, and scalability. Overcoming these barriers demands targeted research and development, policy support, and investment in local feed innovation to ensure sustainable aquaculture growth. This study underscores the critical need for further research and strategic implementation of alternative feed resources to enhance the sustainability, profitability, and resilience of aquaculture in Bangladesh, with a focus on optimizing inclusion levels, improving digestibility, and utilizing locally available ingredients to ensure nutritional balance and food security.