Alternate protein sources for salmon and trout diets

Growth of aquaculture throughout the world requires increased production of fish feeds. Increased production of fish feed will require increased quantities of feed ingredients, mainly protein sources. Most high-value species of fish raised by aquaculture are carnivores requiring feeds containing 400 g kg−1 or more protein, generally supplied by fish meal. World fish meal production is not expected to increase beyond current levels. This has stimulated research into alternatives to fish meal to supply protein in fish feeds, such as animal and fish processing by-product meals, oilseed proteins and concentrates, and protein concentrates produced from grains. Most alternate protein sources have one or more negative attributes that limit their use in fish feeds. One major concern is how the use of alternate protein sources affect the content of fish farm effluent water. Innovative research on reducing or mitigating the negative qualities of alternate protein sources is increasing the potential for their use in fish feeds and will help alleviate future demands for fish meal by the aquaculture industry.