Sustainable Aquafeeds

One of the most important goals of aquaculture nutrition research is to find a protein source with adequate nutritive properties to replace fishmeal in aquafeed. Nevertheless, nowadays innovative protein sources involve new protein sources, which is a holistic concept of protein that includes nutritional quality, availability, price, food safety, human competition, and sustainability to allow the protein source to form part of a circular economy. \n \nIn this chapter, six promising innovative protein sources are studied for nutritive value, constraints, advantages of the environment, production, and experiences in aquaculture. \n \nKrill, with an estimated biomass of around 500 million tons, is an excellent source of vitamins, minerals, essential amino acids, n-3 polyunsaturated fatty acids (FA), natural carotenoid pigments, nucleotides, and organic acids, and has good prospects as a fishmeal (FM) substitute. \n \nInsect breeding shows several environmental benefits, and is one of the most promising protein sources for feed production with markedly increased production in recent years. \n \nYeasts are potential sustainable ingredients in aquafeeds given the ability to convert low-value lignocellulosic biomass into high-value feed with limited dependence on land, water, and climate conditions, and with a similar essential amino acid profile to FM. \n \nBioflocs are heterogeneous aggregates with variable protein levels ranging from 7.7% to 50%, and with lipid levels between less than 0.1 and 9.9 on a dry matter basis. \n \nMicroalgae algal biomass is a rich source of nutrients, such as proteins, n-3 FA, and carbohydrates, and of vitamins, minerals, and other bioactive compounds like antioxidants. \n \nThe vegetable protein sources have been widely studied and countless of them have been proposed as fish meal substitutes. This chapter focuses on sources with nutritive quality, that are available all year, at low cost and with minimal handling, transport, and processing.