From the abundant skipjack to the rare bluefin, we look at the different tuna species, the areas they inhabit, and the impact of commercial tuna fishing over the years.
Tuna belong to the Thunnini tribe, a taxonomic rank above genus but below family.
Thunnini are a subgroup of the Scombridae, or mackerel, family.
Sizes of tuna can vary greatly across the 15 individual species, ranging from bullet tuna, which measures a maximum length of around 50 centimeters, to the Atlantic bluefin, that grows up to 4.6 meters long and lives up to 40 years.
Along with opah and mackerel sharks, tuna are one of a few fish species that can regulate their own temperature—they can maintain a higher temperature than the surrounding water. With an agile, sleek, streamlined body, tuna are built for speed, with yellowfin tuna reaching speeds of up to 47 miles per hour.
The Thunnini fish tribe comprises 5 separate genera:
- Thunnus (true tunas)
- Allothunnus (slender tunas)
- Euthynnus (little tunas)
- Auxis (frigate tunas)
- Katsuwonus (skipjack tunas)
The 15 individual tuna species are:
- Albacore tuna
- Southern bluefin tuna
- Bigeye tuna
- Pacific bluefin tuna
- Atlantic bluefin tuna
- Blackfin tuna
- Longtail tuna
- Yellowfin tuna
- Slender tuna
- Bullet tuna
- Frigate tuna
- Mackerel tuna
- Little tunny
- Black skipjack tuna
- Skipjack tuna
The most commonly eaten species are yellowfin, albacore, skipjack, bigeye, and bluefin.
Also known as ahi tuna, yellowfin tuna is a healthy, relatively inexpensive protein source. It has a deep pink color and a mild flavor, making it perfect for sushi rolls. This mid-sized tuna starts reproducing at the age of two, spawning throughout the year. They are highly migratory, roaming across subtropical and tropical zones in all of the world’s oceans.
Albacore tuna is the highest-grade canned white tuna sold in the United States. It is also sold fresh and frozen. The fish has a torpedo-shaped body, with blue and silver coloration. It is a schooling fish that migrates as far north as the Bay of Biscay. In the Pacific, albacore are found off the West Coast of America, and in waters around Hawaii.
Skipjack is the most commonly canned tuna species. The fish has the strongest flavor of all tropical tunas. High quality skipjack meat is a deep red color when raw, turning light gray as it cooks.
Bigeye tuna prefer deeper, cooler waters than most species of tropical tuna. They are bigger than skipjack and albacore, but smaller than bluefin. Bigeye are also highly migratory. They have a firm, meaty texture with large flakes and a rich, but mild flavor. With a reddish-pink meat and high fat content, they are highly prized in the sashimi market.
Bluefin are the biggest tuna species. They migrate across the world’s oceans, diving to depths of more than 3,000 feet.
With retractable fins, eyes set flush to their body, and a characteristic torpedo shape, bluefin tuna are built for speed. They are voracious predators, seeking out prey from the moment they hatch. Bluefins have the sharpest sight of any bony fish, seeking out schools of mackerel, herring, and eels. They can weigh up to 1,500 pounds and live for up to 40 years.
Americans eat up to a billion pounds of pouched and canned tuna annually.
Only sugar and coffee exceed sales per foot of shelf space in grocery stores.
After shrimp, canned tuna is the second most popular seafood in the United States. The European Union, United States, and Japan are the world’s biggest canned tuna consumers, representing 51%, 31%, and 6% of global canned tuna sales, respectively.
The vast majority (88%) of American families have bought canned tuna. Of those, 50% purchase it at least once a month.
In addition, 83% of Americans who buy canned tuna eat it for lunch. Canned tuna is, in fact, the only seafood Americans regularly consume at lunch.
Historical overfishing has seriously depleted tuna stocks in some areas of the world.
Bluefin tuna, which is considered a delicacy in Japan, has been catastrophically overfished. Bluefin tuna stocks in the Pacific have declined by 96% in the wild. The species is considered critically endangered by conservationists, with decades of demand and hefty price tags meaning it has been hunted to the brink of extinction.
Not all tuna species are endangered, however. Skipjack tuna, which accounts for around 70% of all pouched and canned tuna, is cheap and plentiful. This small fish matures very quickly, making it more sustainable. It also ranks lower on the food chain, meaning that levels of mercury in skipjack flesh are relatively low.
The MSC supports sustainable fishing to protect the tuna industry.
The MSC, or Marine Stewardship Council, operates a voluntary blue label scheme, promoting traceability and the adoption of sustainable practices throughout the tuna fishing industry.
The organization protects public interests, ensuring that when customers buy canned tuna, they’re getting exactly what the label says. In addition, MSC works to protect tuna stocks for future generations, as well as the future of the tuna fishing industry.