Fish and fish products are consumed as food all over the world. With other seafoods, it provides the world's prime source of high-quality protein: 14–16 percent of the animal protein consumed worldwide. Over one billion people rely on fish as their primary source of animal protein.
Fish and other aquatic organisms are also processed into various food and non-food products.
Sharkskin and rayskin which are covered with, in effect, tiny teeth (dermal denticles) were formerly used in the same manner as sandpaper is in the modern era. These skins are also used to make leather. Rayskin leather (same'gawa) is used in the manufacture of hilts of traditional Japanese swords. Some other species of fish are also used to make fish leather, and this material is more and more popular among luxury brands such as Prada, Dior, Fendi, and also emerging designers. Thus, it is now possible to wear shoes made of salmon leather, a jacket made of perch leather, or a handbag made of wolffish or cod leather. Once tanned, the leather is non-odorous and is stronger than other, traditional, leathers of similar thickness.
The flesh of many fish are primarily valued as a source of food; there are many edible species of fish, and many fish produce edible roe. Other marine life taken as food includes shellfish, crustaceans, and sea cucumber. Sea plants such as kombu are used in some regional cuisine.
Surimi refers to a Japanese food product intended to mimic the meat of lobster, crab, and other shellfish. It is typically made from white-fleshed fish (such as pollock or hake) that has been pulverized to a paste and attains a rubbery texture when cooked.
Fish meal is made from both whole fish and the bones and offal from processed fish. It is a brown powder or cake obtained by rendering pressing the whole fish or fish trimmings to remove the fish oil. It used as a high-protein supplement in aquaculture feed.
Fish sauce is a condiment that is derived from fish that have been allowed to ferment. It is an essential ingredient in many curries and sauces.
A shimmery substance found on fish scales, most usually obtained from herring and one of many by-products of commercial fish processing, can also be used for pearlescent effects, primarily in nail polish, but is now rarely used due to its high cost, bismuth oxychloride flakes being used as a substitute instead.