Fish and seafood processing leftovers are widely recognized as a potential source of large amounts of different valued biomolecules and biomaterials. Fish processing increases the stability and quality of products, removing parts, such as the viscera containing bacteria and enzymes that would otherwise quickly deteriorate proteins besides easing oxidation of the omega-3 polyunsaturated fatty acids (PUFAs) abundant in sea life lipids. In 2011 more than 70% of the total fish caught was reported to subjected to processing before reaching the marketplace, with fish industry by-products accounting up to 75% of the catch (depending on post-fishing and industrial processing processes) and on average 50% in weight. Since then, the share of processed fish has increased due to further economic development of numerous countries.