Spaghetti with seafood (Spaghetti allo scoglio). Seafood is any sea animal or seaweed that is served as food or is suitable for eating, particularly seawater animals, such as fish and shellfish (including mollusks and crustaceans). By extension, in North America although not generally in the United Kingdom, the term seafood is also applied to similar animals from fresh water and all edible aquatic animals are collectively referred to as seafood. Edible seaweeds are also seafood, and are widely eaten around the world. See the category of sea vegetables. The harvesting of seafood is known as fishing and the cultivation of seafood is known as aquaculture, mariculture, or simply fish farming. Seafood is a source of protein in many diets around the world.