A method of preserving fish includes: cleaning a fish and preparing a fillet from the fish; removing a blood line from the fillet by forming the fillet with a shallow cut along the blood line, the blood line extending along a lateral side of the fish proximate to a skin of the fish; packing the fillet in a vacuumed package which includes oxygen and which has a vacuum pressure ranging from 80% to 95% of atmosphere; and freezing the packaged fillet.