Marine byproducts for aquaculture use

Aquaculture production increased by more than 12% per year in the past 15 years and is expected to continue to do so for the foreseeable future, requiring more feeds and thus more fish protein and oil. The percentage of annual world fish meal and oil production used by the aquaculture feed industry was 10% and 6% in 1988 compared to ca. 43% and 75%, respectively, in 2000. Over 70% of the fish meal and oil consumed by aquaculture is used in feeds for four species groups, i.e., marine shrimp, salmonids, marine fish, and carp. Fish meal and oil fulfill specific roles in feeds for each species group, and thus marine byproducts can have different specifications for each. The amino acid profile of fish meal is optimum for aquaculture feeds, but supply and demand concerns will increasingly result in fish meal being combined with grain and oilseed proteins to produce blends suitable for growing fish. Thus, the protein and amino acid content and digestibility of fish meal and marine byproducts will become critically important as proteins from marine sources switch from a primary role in feeds to a specialty role as sources of essential amino acids that are limited in proteins from grains and oilseeds. Likewise, fish oils will switch from being a primary energy source in diets to a specialty role in finishing diets to supply omega-3 fatty acids.