• 
• printer-friendly version
• 
• email to a friend

Because of its taste, texture and versatility, tuna is enjoyed around the world and served under many different names:

• Dutch — Tonijn
• French — Thon
• German — Thunfisch
• Greek — Tovoc
• Italian — Tonno
• Portuguese — Atum
• Russian — Tyheli
• Spanish — Atun
• Swedish — Tonfish

The most popular fish used for canning today, tuna is a member of the mackerel family and is prized for its distinctively rich-flavored flesh that is moderate to high in fat, firmly textured, flaky and tender.

Found in all oceans around the world with the exception of the polar seas, tuna inhabits the upper and middle layers of ocean water to a depth of 1,600 feet or more (500 meters), depending on size and species. Tuna roam long distances and are agile predators, often feeding on smaller, schooling fishes. Their species of prey include herring, menhaden, hake, cod, bluefish, whiting, and mackerel, as well as squid and crustaceans such as shrimp.

The circulatory and respiratory system of tuna is unique among fish - enabling them to maintain a body temperature slightly higher than the surrounding water. This additional heat, when transmitted to oxygen-rich blood, gives an extra boost to already powerful muscles. Some tunas can reach speeds of over 40 miles per hour for short distances. The tuna's steady, powerful swimming sustains a uniquely high metabolic rate, which means that tuna grow at an extraordinary rate. This also places a large oxygen demand on the fish, requiring tuna to swim continuously in order to meet that demand. Tuna must swim at a rate of at least one body length per second to pass enough oxygen over their gills.

Because of their size, large tuna have few predators besides billfish, some sharks, toothed whales such as orcas and pilot whales, and humans.

Commercial Tuna Varieties

Among the world's most valuable commercial species, tuna are fished in over 70 countries worldwide, and marketed in fresh, frozen, or canned form. The most important commercial species include:

Albacore — A high-fat variety, rich in omega-3 fatty acids, the albacore has the lightest flesh, white with a hint of pink, and is the only tuna that can be called white. Its mild flavor and prized white flesh make it the most expensive canned tuna.

Yellowfin — Also called ahi, the yellowfin tuna is usually larger than albacore, reaching up to 300 pounds. Their flesh is pale pink and must be called "light", with a flavor slightly stronger than albacore.

Bluefin — Among the largest tunas are the bluefin, which can weigh over 1,000 pounds. Young bluefins have a lighter flesh and are milder in flavor. As they grow into adulthood, their flesh turns dark red and their flavor becomes more pronounced. Bluefin tuna is used in sushi and sashimi and is not canned.

Skipjack — Similar in flesh to the yellowfin, skipjack can weigh up to 40 pounds but typically range from 6 to 8 pounds. The fish get their name because of their lively movement in the water, where they seem to skip along the surface. Also known as arctic bonito, oceanic bonito, watermelon and, in Hawaii, aku, Skipjack is the most commonly canned fish on the market today.

Bigeye — Known in Hawaii as ahi, bigeye tuna are similar in general appearance to yellowfin tuna and are the deepest ranging of all tuna species, with a range of greatest concentration at 150 to 250 fathoms. With its mild flavor and desirable fat content, the bigeye is often used in canned tuna.

Japan and the United States consume about 36 percent and 31 percent, respectively, of the world's catch. Depending on the variety, fresh tuna is available seasonally - generally beginning in late spring and continuing into early fall. Frozen tuna is available year-round and is sold in both steaks and fillets. It may be baked, broiled, grilled or fried in cooking. Canned tuna is precooked and sold as albacore, or white meat, and light meat and can be safely kept on hand for up to five years.

About Canned Tuna

Americans eat about one billion pounds of canned and pouched tuna annually. The many varieties are distinguished by the type of meat, "white" or "light," packed in water or oil. In the U.S., most canned tuna is available as either "solid" or "chunk." According to the Food and Drug Administration (FDA) - which set strict definitions for how canned tuna is marketed - the difference between "solid" and "chunk" is as follows:

• Solid, also called "fancy" — a solid portion of a loin, cut to fit the can, and packed in one layer.
• Chunk — a mixture of cut pieces of varying sizes.

Chunk, light meat in water is the most popular light meat pack. The source of most chunk, light meat is Skipjack, although other species of tuna can be added. Albacore, which is the only tuna species that can be called "white," is packed almost exclusively in water in solid form.

Where Tuna Are Harvested

Although tuna is found in all major bodies of water except the polar seas, the majority of the tuna supply comes from the Pacific Ocean - which accounts for 2.3 million tons or about 66 percent of the total world catch. The rest of the commercial tuna sold around the world comes from the Indian Ocean (20.7 percent), the Atlantic Ocean (12.5 percent) and the Mediterranean and Black Seas (0.8 percent).

Total world tuna catches by ocean, 1995-2000 (metric tons)