Seafood

Seafood refers to any form of sea life regarded as food by humans.

This category includes a vast range of organisms, most notably fish and various types of shellfish. It also encompasses edible sea plants, such as certain seaweeds and microalgae, which are widely consumed as sea vegetables. For many people, especially those living in coastal regions, seafood serves as a vital source of animal protein. Those who choose to eat seafood but avoid all other types of meat are known as pescetarians. Beyond direct human consumption, seafood plays many roles in global systems. It is used as food for farmed fish and other animals. Some species, like kelp, even serve as fertilizer for plants.

Humans obtain seafood through two primary methods: harvesting and cultivation. Harvesting wild seafood is commonly called fishing or hunting. In contrast, the intentional farming of aquatic life is known as aquaculture. When specifically referring to the farming of fish, the term fish farming is used. Modern aquaculture utilizes hatcheries to manage reproductive cycles. This technology allows for more controlled growth of aquatic species. Improved preservation methods have also emerged to handle the hazards of raw or undercooked seafood. These advancements ensure that seafood remains a safe and reliable food source for a growing population.

Fish are aquatic vertebrates that breathe using gills and lack limbs with digits. They are categorized by where they live and how they move. Pelagic fish live and feed near the surface or within the water column.

This group includes large predators like Atlantic bluefin tuna and smaller forage fish like sardines. Demersal fish live and feed on or near the ocean floor.

Examples include cod and various flatfish. These fish often have white flesh, whereas pelagic fish frequently have red flesh from powerful swimming muscles. Diadromous fish are unique because they migrate between saltwater and freshwater environments.

Salmon are a well-known example of this migratory behavior. Additionally, freshwater fish live in rivers, lakes, and ponds.

Tilapia is a common example of a species often raised in freshwater farms.

Shellfish include several distinct biological groups, such as molluscs and crustaceans. Molluscs are invertebrates characterized by soft bodies. Bivalves, such as oysters and mussels, possess a protective shell made of two hinged parts, or valves.

Gastropods, or sea snails, are univalves with a single-piece shell.

Cephalopods are highly intelligent molluscs like the octopus and squid that lack an external shell.

Crustaceans are invertebrates with segmented bodies protected by hard exoskeletons made of chitin. This armor-like shell must be shed through a process called moulting. Most commercial crustaceans are decapods, meaning they have ten legs. Examples include shrimp, crabs, and lobsters.

When cooked, the shells of many crustaceans turn pink or red.

Archaeological evidence shows that humans have consumed seafood since the Paleolithic period. Findings at Pinnacle Point in South Africa suggest modern humans harvested marine life 165,000 years ago. At the same time, Neanderthals appear to have eaten seafood along the Mediterranean coast. In ancient Egypt, fish were a staple food, and tomb paintings show people using specific tools for fishing. In ancient Greece, the social status of fishing varied. While some viewed it as a low-status job, the author Oppian wrote a major treatise on the subject. Roman culture also featured seafood, with mosaics depicting fishing activities. During the Roman era, the goatfish was considered a luxury because its scales turned bright red when it died out of water.

Throughout history, the availability and price of seafood have changed based on location and wealth. In the Greek islands, seafood was common and often transported inland. In ancient Boeotia, a stone inscription from the 3rd century BCE listed fish prices. The cheapest was likely parrotfish, while Atlantic bluefin tuna cost three times as much. In medieval times, seafood was often seen as a less prestigious alternative to meat. It was frequently eaten on fast days when meat was restricted. Coastal populations relied on it as a mainstay, such as the herring kippers found in North Sea markets. For inland populations in Central Europe, fish was often much more expensive than meat.

Today, the seafood industry produces massive quantities of food for various purposes. In 2010, total production reached very high levels across different species groups. For example, fish production was measured at over 106,000 thousand tonnes. Seafood is also used to create specialized products like fish oil, spirulina tablets, and fish collagen. Some parts, such as chitin, are used for industrial purposes. A small amount of seafood is even used in medicine or to produce leather. Additionally, seafood serves as food for domestic pets like cats and for fish in aquariums. This demonstrates how deeply seafood is integrated into human economy, nutrition, and industry.