Microalgae-based ingredients have potential to ensure continued growth of salmonid aquaculture for global sustainable food security in the blue economy. Algal biorefineries must valorize the entire crop to grow profitable microalgae-based economies. With massive growth and demand for novel sustainable ingredients, farmed salmonid feed sectors are highly promising areas to focus on. Microalgae-based ingredients for salmonid feeds may have market advantages in terms of lower input costs, aerial foot-print, wastewater remediation benefits and carbon credits for industrial CO2 conversion. A handful of microalgae-based ingredients have been proposed as candidates to supply well-balanced nutrients and immunostimulatory compounds. However, technical gaps exist and need addressing before the industry could economically incorporate microalgae-based ingredients into commercial feeds. Current knowledge on comprehensive biochemical composition is incomplete, highly heterogeneous, and information on their nutritional value is scattered and/or inconsistent. The aim of this chapter is to consolidate relatively fragmented data on biochemical composition and nutritional value of microalgae-based ingredients focusing on farmed salmonid feeds. Presented are discussions on the potential for such ‘next-generation’ ingredients, opportunities/challenges for their use and a compendium of studies evaluating their performance in feeds for economically relevant farmed salmonids, including rainbow trout (Oncorhynchus mykiss), Arctic charr (Salvelinus alpinus) and Atlantic salmon (Salmo salar).
Part of the book: Microalgal Biotechnology