The interest for krill-based ingredients for aquaculture feed applications has increased steadily in recent years. For decades there has been a heavy reliance on the limited sources of fishmeal and fish oil in the salmonid aquaculture industry. Further growth in farming of carnivorous fish is dependent on new feed resources becoming available. The only unexploited marine resources of significant biomass are found at lower trophic levels, of which the Antarctic krill has a high potential. Antarctic krill (Euphausia
superba) is one of the most abundant species on earth, with an estimated biomass of around 500 million tonnes. Krill plays a key role in the marine food chain in the Antarctic Ocean, and hence krill harvesting is highly regulated by the Commission for the Conservation of Antarctic Marine Resources (CCAMLR). These strict regulations of Antarctic krill harvesting have led to an increase in its biomass over the years, from 60.3 million tonnes measured in 2000 to 62.6 million in 2018/19 according to the findings from CCAMLR.
Among the several products produced from Antarctic krill for the aquaculture feed formulations, krill meal is the most vastly used. Krill meal is a sustainable source of protein, n-3 phospholipids, feed attractants (nucleotides, free amino acids, TMAO) and astaxanthin. It has a proximate composition that is similar to fish meal with an almost identical amino acid profile. The lipid fraction of krill meal contains a high proportion of polar lipids, as well as a high content of polyunsaturated fatty acids (PUFAs), sterols (mainly cholesterol) and astaxanthin esters . The present article provides an overview on the documented benefits of krill meal,
focusing on feed intake, growth performance , fillet quality, slaughter yield, and health benefits in terms of reducing fat accumulation and inflammation in liver and intestinal tissues in salmonids.