Seafood

Seafood is any form of sea life that people eat, mostly fish and shellfish. Shellfish include animals like clams, oysters, mussels, octopus, squid, shrimp, crabs, and lobster. In the past, people also ate marine mammals like whales and dolphins, but this happens less often today. Some people eat seaweeds and tiny plants called microalgae, especially in parts of Asia.

Seafood includes any form of food taken from the sea.

Seafood is a very important source of protein for many people around the world, especially near the ocean. It is a main part of the diet for many coastal communities. Some people who don’t eat land animals but do eat seafood are called pescetarian. Getting seafood from the wild is called fishing or hunting, while growing it on farms is called aquaculture or fish farming.

Most of the seafood caught or farmed is eaten by people, but some is used to feed other fish or farm animals. Some types of seafood, like kelp, are used to help grow plants as a kind of fertilizer. Seafood is also used to make products like fish oil, tablets called spirulina, and other useful materials. A small amount of seafood is even used to feed pets like cats or fish in aquariums.

History

Main article: History of seafood

Various foods depicted in an Egyptian burial chamber, including fish, c. 1400 BCE

People have eaten seafood for a very long time. Scientists found proof that humans were eating sea life over 165,000 years ago. Even ancient humans, like the Neanderthals, ate seafood near the Mediterranean coast.

Old drawings, shells, and fish bones show that seafood was important to early people. In ancient Egypt, fish from the Nile River were often eaten. Fish was also important in ancient Greece and Rome. Over time, people learned better ways to raise fish and keep seafood safe to eat.

Types of seafood

The table below shows different kinds of seafood. It uses a system called ISSCAAP, made by the FAO. The numbers come from the FAO FishStat database. They include fish caught in the wild and fish farmed.

Group	Image	Subgroup	Description	2010 production 1000 tonnes
fish	Fish are aquatic vertebrates which lack limbs with digits, use gills to breathe, and have heads protected by hard bone or cartilage skulls. See: Fish (food). Total for fish:			106,639
		marine pelagic	Pelagic fish live and feed near the surface or in the water column of the sea, but not on the bottom of the sea. The main seafood groups can be divided into larger predator fish (sharks, tuna, billfish, mahi-mahi, mackerel, salmon) and smaller forage fish (herring, sardines, sprats, anchovies, menhaden). The smaller forage fish feed on plankton, and can accumulate toxins to a degree. The larger predator fish feed on the forage fish, and accumulate toxins to a much higher degree than the forage fish.	33,974
		marine demersal	Demersal fish live and feed on or near the bottom of the sea. Some seafood groups are cod, flatfish, grouper and stingrays. Demersal fish feed mainly on crustaceans they find on the sea floor, and are more sedentary than the pelagic fish. Pelagic fish usually have the red flesh characteristic of the powerful swimming muscles they need, while demersal fish usually have white flesh.	23,806
		diadromous	Diadromous fish are fishes which migrate between the sea and fresh water. Some seafood groups are salmon, shad, eels and lampreys. See: Salmon run.	5,348
		freshwater	Freshwater fish live in rivers, lakes, reservoirs, and ponds. Some seafood groups are carp, tilapia, catfish, bass, and trout. Generally, freshwater fish lend themselves to fish farming more readily than the ocean fish, and the larger part of the tonnage reported here refers to farmed fish.	43,511
molluscs	Molluscs (from the Latin molluscus, meaning soft) are invertebrates with soft bodies that are not segmented like crustaceans. Bivalves and gastropods are protected by a calcareous shell which grows as the mollusc grows. Total for molluscs:			20,797
		bivalves	Bivalves, sometimes referred to as clams, have a protective shell in two hinged parts. A valve is the name used for the protective shell of a bivalve, so bivalve literally means two shells. Important seafood bivalves include oysters, scallops, mussels and cockles. Most of these are filter feeders which bury themselves in sediment on the seabed where they are safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some, such as scallops, can swim. Bivalves have long been a part of the diet of coastal communities. Oysters were cultured in ponds by the Romans and mariculture has more recently become an important source of bivalves for food.	12,585
		gastropods	Aquatic gastropods, also known as sea snails, are univalves which means they have a protective shell that is in a single piece. Gastropod literally means stomach-foot, because they appear to crawl on their stomachs. Common seafood groups are abalone, conch, limpets, whelks and periwinkles.	526
		cephalopods	Cephalopods, except for nautilus, are not protected by an external shell. Cephalopod literally means head-foots, because they have limbs which appear to issue from their head. They have excellent vision and high intelligence. Cephalopods propel themselves with a water jet and lay down "smoke screens" with ink. Examples are octopus, squid and cuttlefish. They are eaten in many cultures. Depending on the species, the arms and sometimes other body parts are prepared in various ways. Octopus must be boiled properly to rid it of slime, smell, and residual ink. Squid are popular in Japan. In Mediterranean countries and in English-speaking countries squid are often referred to as calamari. Cuttlefish is less eaten than squid, though it is popular in Italy and dried, shredded cuttlefish is a snack food in East Asia. See: Squid (food), Octopus (food).	3,653
		other	Molluscs not included above are chitons.	4,033
crustaceans	Crustaceans (from Latin crusta, meaning crust) are invertebrates with segmented bodies protected by hard crusts (shells or exoskeletons), usually made of chitin and structured somewhat like a knight's armour. The shells do not grow, and must periodically be shed or moulted. Usually two legs or limbs issue from each segment. Most commercial crustaceans are decapods, that is they have ten legs, and have compound eyes set on stalks. Their shell turns pink or red when cooked. Total for crustaceans:			11,827
		shrimps	Shrimp and prawns are small, slender, stalk-eyed ten-legged crustaceans with long spiny rostrums. They are widespread, and can be found near the seafloor of most coasts and estuaries, as well as in rivers and lakes. They play important roles in the food chain. There are numerous species, and usually there is a species adapted to any particular habitat. Any small crustacean which resembles a shrimp tends to be called one. See: shrimp (food), shrimp fishery, shrimp farming, freshwater prawn farming.	6,917
		crabs	Crabs are stalk-eyed ten-legged crustaceans, usually walk sideways, and have grasping claws as their front pair of limbs. They have small abdomens, short antennae, and a short carapace that is wide and flat. Also usually included are king crabs and coconut crabs, even if these belongs to a different group of decapods than the true crabs. See: crab fisheries.	1,679
		lobsters	Clawed lobsters and spiny lobsters are stalk-eyed ten-legged crustaceans with long abdomens. The clawed lobster has large asymmetrical claws for its front pair of limbs, one for crushing and one for cutting (pictured). The spiny lobster lacks the large claws, but has a long, spiny antennae and a spiny carapace. Lobsters are larger than most shrimp or crabs. See: lobster fishing.	281
		krill	Krill resemble small shrimp, however they have external gills and more than ten legs (swimming plus feeding and grooming legs). They are found in oceans around the world where they filter feed in huge pelagic swarms. Like shrimp, they are an important part of the marine food chain, converting phytoplankton into a form larger animals can consume. Each year, larger animals eat half the estimated biomass of krill (about 600 million tonnes). Humans consume krill in Japan and Russia, but most of the krill harvest is used to make fish feed and for extracting oil. Krill oil contains omega-3 fatty acids, similar to fish oil. See: Krill fishery.	215
		other	Crustaceans not included above are gooseneck barnacles, giant barnacle, mantis shrimp and brine shrimp.	1,359
other aquatic animals	Total for other aquatic animals:			1,409+
		aquatic mammals	Marine mammals form a diverse group of 128 species that rely on the ocean for their existence. Whale meat is still harvested from legal, non-commercial hunts. About one thousand long-finned pilot whales are still killed annually. Japan has resumed hunting for whales, which they call "research whaling". In modern Japan, two cuts of whale meat are usually distinguished: the belly meat and the more valued tail or fluke meat. Fluke meat can sell for $200 per kilogram, three times the price of belly meat. Fin whales are particularly desired because they are thought to yield the best quality fluke meat. In Taiji in Japan and parts of Scandinavia such as the Faroe Islands, dolphins are traditionally considered food, and are killed in harpoon or drive hunts. Ringed seals are still an important food source for the people of Nunavut and are also hunted and eaten in Alaska. The meat of sea mammals can be high in mercury, and may pose health dangers to humans when consumed. The FAO records only the reported numbers of aquatic mammals harvested, and not the tonnage. In 2010, it reported 2500 whales, 12,000 dolphins and 182,000 seals. See: marine mammals as food, whale meat, seal hunting.	?
		aquatic reptiles	Sea turtles have long been valued as food in many parts of the world. Fifth century BC Chinese texts describe sea turtles as exotic delicacies. Sea turtles are caught worldwide, although in many countries it is illegal to hunt most species. Many coastal communities around the world depend on sea turtles as a source of protein, often gathering sea turtle eggs, and keeping captured sea turtles alive on their backs until needed for consumption. Most species of sea turtle are now endangered, and some are critically endangered.	296+
		echinoderms	Echinoderms are headless invertebrates, found on the seafloor in all oceans and at all depths. They are not found in fresh water. They usually have a five-pointed radial symmetry, and move, breathe and perceive with their retractable tube feet. They are covered with a calcareous and spiky test or skin. The name echinoderm comes from the Greek ekhinos meaning hedgehog, and dermatos meaning skin. Echinoderms used for seafood include sea cucumbers, sea urchins, and occasionally starfish. Wild sea cucumbers are caught by divers and in China they are farmed commercially in artificial ponds. The gonads of both male and female sea urchins, usually called sea urchin roe or corals, are delicacies in many parts of the world.	373
		jellyfish	Jellyfish are soft and gelatinous, with a body shaped like an umbrella or bell which pulsates for locomotion. They have long, trailing tentacles with stings for capturing prey. They are found free-swimming in the water column in all oceans, and are occasionally found in freshwater. Jellyfish must be dried within hours to prevent spoiling. In Japan they are regarded as a delicacy. Traditional processing methods are carried out by a jellyfish master. This involve a 20 to 40-day multi-phase procedure which starts with removing the gonads and mucous membranes. The umbrella and oral arms are then treated with a mixture of table salt and alum, and compressed. Processing reduces liquefaction, odor, the growth of spoilage organisms, and makes the jellyfish drier and more acidic, producing a crisp and crunchy texture. Only scyphozoan jellyfish belonging to the order Rhizostomeae are harvested for food; about 12 of the approximately 85 species. Most of the harvest takes place in southeast Asia.	404
		other	Aquatic animals not included above, such as waterfowl, frogs, spoon worms, peanut worms, palolo worms, lamp shells, lancelets, sea anemones and sea squirts (pictured).	336
aquatic plants and microphytes	Total for aquatic plants and microphytes:			19,893
		seaweed	Seaweed is a loose colloquial term which lacks a formal definition. Broadly, the term is applied to the larger, macroscopic forms of algae, as opposed to microalga. Examples of seaweed groups are the multicellular red, brown and green algae. Edible seaweeds usually contain high amounts of fibre and, in contrast to terrestrial plants, contain a complete protein. Seaweeds are used extensively as food in coastal cuisines around the world. Seaweed has been a part of diets in China, Japan, and Korea since prehistoric times. Seaweed is also consumed in many traditional European societies, in Iceland and western Norway, the Atlantic coast of France, northern and western Ireland, Wales and some coastal parts of South West England, as well as Nova Scotia and Newfoundland. See: edible seaweed, seaweed farming, aquaculture of giant kelp, laverbread.
		microphytes	Microphytes are microscopic organisms, and can be algal, bacterial or fungal. Microalgae are another type of aquatic plant, and includes species that can be consumed by humans and animals. Some species of aquatic bacteria can also be used as seafood, such as spirulina (pictured in tablet form), a type of cyanobacteria. See: culture of microalgae in hatcheries.
		aquatic plants	Edible aquatic plants are flowering plants and ferns that have adapted to a life in water. Known examples are duck potato, water chestnut, cattail, watercress, lotus and nardoo.
Total production (thousand tonnes)				168,447

Processing

Seafood is food from the sea, such as fish and shellfish. Fish can spoil quickly, so it needs to be eaten soon or kept cold. Some places keep fish alive until customers are ready to eat them.

There are many ways to keep fish fresh longer. Old methods include drying and salting the fish. Some fish are cooked and canned, like salmon and tuna. Fresh fish is often kept on ice or in cold storage for sale.

Consumption

People around the world eat seafood because it gives them important nutrients. Seafood provides a lot of good protein, and many people depend on it for protein. Fish can sometimes cause allergic reactions in some people.

Since 1960, the amount of seafood people eat each year has grown a lot. Some countries where people eat a lot of seafood include Korea, Norway, and Portugal.

Experts suggest eating at least two servings of seafood each week, with one of them being from oily fish like mackerel or herring. These oily fish contain omega-3 oils, which are important for our brains and bodies.

Other types of fish, such as haddock and cod, have very little fat and can help keep our hearts healthy. Shellfish, like oysters, are rich in zinc, which helps our skin and muscles stay healthy.

Texture and taste

There are many kinds of fish and sea creatures that we can eat. Sea animals taste different from freshwater fish because of special chemicals made by sea plants. When we cook fresh fish and shellfish, it can smell like the ocean. Deeper sea fish taste stronger than fish in shallower water. Some sea plants also give special smells that add to the flavor of edible seaweeds.

Common species used as seafood
	Mild flavour	Moderate flavour	Full flavour
Delicate texture	basa, flounder, hake, scup, smelt, rainbow trout, hardshell clam, blue crab, peekytoe crab, spanner crab, cuttlefish, eastern oyster, Pacific oyster	anchovy, herring, lingcod, moi, orange roughy, Atlantic Ocean perch, Lake Victoria perch, yellow perch, European oyster, sea urchin	Atlantic mackerel
Medium texture	black sea bass, European sea bass, hybrid striped bass, bream, cod, drum, haddock, hoki, Alaska pollock, rockfish, pink salmon, snapper, tilapia, turbot, walleye, lake whitefish, wolffish, hardshell clam, surf clam, cockle, Jonah crab, snow crab, crayfish, bay scallop, Chinese white shrimp	sablefish, Atlantic salmon, coho salmon, skate, dungeness crab, king crab, blue mussel, greenshell mussel, pink shrimp	escolar, chinook salmon, chum salmon, American shad
Firm texture	Arctic char, carp, catfish, dory, grouper, halibut, monkfish, pompano, Dover sole, sturgeon, tilefish, wahoo, yellowtail, Abalone, conch, stone crab, American lobster, spiny lobster, octopus, black tiger shrimp, freshwater shrimp, gulf shrimp, Pacific white shrimp, squid	barramundi, cusk, dogfish, kingklip, mahimahi, opah, mako shark, swordfish, albacore tuna, yellowfin tuna, geoduck clam, squat lobster, sea scallop, rock shrimp	barracuda, Chilean sea bass, cobia, croaker, eel, blue marlin, mullet, sockeye salmon, bluefin tuna

Health benefits

Eating seafood is good for your brain, especially when you are very young. Fish contain important fats that help your brain grow and stay healthy. Experts say that eating fish can help protect against some illnesses.

Different parts of fish have useful nutrients. Governments suggest eating fish a few times each week as part of a balanced diet. For example, in the United States, children are advised to eat about 4 ounces of fish each week, while adults should aim for 8 to 12 ounces. Other countries have similar guidelines.

Health hazards

When eating seafood, there are some health concerns to think about. These include harmful substances from the ocean, tiny living things that can make you sick, and pollution from human activities. Shellfish can also cause allergic reactions in some people. Knowing where and when seafood was caught can help avoid these problems.

Some types of fish can make you sick if you eat them. For example, eating fish that have a special kind of toxin can cause an illness. Another illness can happen when eating fish that have too much of a certain substance because they were not stored properly.

Fish and shellfish can also collect harmful substances from the water. Bigger fish, such as shark, swordfish, and tuna, usually have more of these substances because they eat other fish. This is called biomagnification.

Mislabelling

Seafood has many types, so sellers sometimes mix up or label it incorrectly. In the United States, many seafood products come from other countries, and only a small amount is checked to make sure it is correct. Some studies show that a lot of seafood might be mislabeled.

There are many reasons for this, like the complicated way food moves from the ocean to stores, mixing up different fish, and using wrong labels. For example, fish like snapper and tuna are often sold under the wrong name. Sometimes, stores sell cheaper fish instead of more expensive ones.

This can be risky because some mislabeled fish might have harmful substances. For instance, some fish might have too much mercury, which can be bad for health. Other times, fish might be unsafe to eat and cause health problems.

Sustainability

Researchers are learning how fish and sea animals are changing. Some say that if we do not change how we catch fish, many kinds might disappear by the year 2048. This could hurt the oceans and all the life there.

A big study in 2006 showed that about one-third of fish groups around the world had very few left. But later work in 2009 suggested that with better rules and care, we can help fish groups grow again. More recent research says we might catch more fish in a way that doesn’t harm the ocean, but this depends on many things like new technology and good decisions.

In religion

Different religions have different rules about eating seafood. In Jewish tradition, following Kashrut rules, people do not eat shellfish or eels. The Mosaic covenant allowed eating fish but not shellfish or eels.

In the early Christian Church, many people followed a diet called Pescatarianism, which means eating only fish and seafood. During Lent, a special time for many Catholic Christians when they do not eat meat, fish became a popular choice. This led to many places offering special seafood meals on Fridays during Lent.