The seafood industry generates large volumes of waste, including processing discards, voluminous amounts of wastewater discharged as effluents, and low-value, underutilized fish. This waste contains valuable nutrients, proteins, amino acids, carotenoids, and other materials, and poses serious environmental problems. Some methods of waste treatment use chemical methods, which have inherent weaknesses. Biological methods are safe, environmentally friendly, and cost-effective.
Biological solutions based on natural processes such as microbial fermentation and exogenously added enzymes recover valuable ingredients from seafood waste. Algal biotechnology has developed unique technologies for the biotransformation of nutrients, and single cell proteins can be used as feedstock for valuable ingredient recovery and a source of biofuel. These innovative bioconversion methods can help achieve a cost-effective and sustainable solution for seafood waste management. Bioconversion techniques can support the development of circular bioeconomies and contribute to sustainable seafood production.
Conventional processes for valorization of seafood involve chemical and physical methods and have several limitations. For instance, chitin extraction from crustacean shells involves initial alkali treatment and partial deacetylation, which reduces the amount of protein extracted. The process also requires high volumes of fresh water, which reduces its usefulness. Further, the loss of amino acids is a major drawback of this process. In addition, it is not cost-effective to treat large amounts of seafood waste.
In Bangladesh, shrimp is the second-largest export after readymade garments. The processing of shrimp and cultured finfish generates substantial amounts of byproducts. Despite these byproducts, however, there is no reliable information on the total volume of seafood waste in Bangladesh. However, in Chittagong and Khulna, shrimp and fish waste are the largest by-products produced in the country. It is important to consider all of these factors when assessing the potential for seafood waste management.