There are nine recognized species of tuna, which is a marine fish which spends the majority of its life in the middle depths of open water. Tuna is probably the most widely commercially harvested fish family, with more being landed every year by heavy producers such as Japan, France, the United States, Taiwan, and Spain. The meat appears in a wide range of traditional foods as well as canned, and the growing numbers of tuna being fished have raised concerns about the longevity of the family.
All tuna species are fished commercially, but Bluefin, Yellow fin, Albacore, and Skipjack are the most heavily fished. Bluefin, in particular, is highly prized in Japan, where the fish of the highest quality is used in sushi and sashimi. Albacore and Skipjack are often cooked and canned in oil or water for sale throughout the world, and Yellow fin is frequently labeled as “Ahi” for sale in Hawaii and along the Western coast of the United States.
Tuna tends to have darker meat than some other fish species, which stands up well to grilling and other robust cooking operations. The meat is high in protein and Omega 3, but unfortunately also accumulates mercury, like many fish species. As a result, consumers should limit their consumption, with some biologists recommending a serving or less per month for some species, particularly Bluefin.
This fish has traditionally been caught for commercial use in large nets, many of which inadvertently capture dolphins as well. After a public awareness campaign about the affectionate marine mammals encouraged a boycott of the tuna industry, many commercial companies began taking steps to prevent dolphins from being caught along with their tuna, billing the result as “dolphin safe.” Some is also caught on long lines, especially by sport fishermen who enjoy doing battle with the muscular and determined fish.
Tuna is popular among humans because it does not have a strong fishy flavor, and consumers who do not like fish will often eat tuna. It is an extremely versatile fish, thanks to the sturdy flesh, and can be found canned, dried, fermented, and fresh across most of the world. Fresh fish is landed daily at major fish markets in the United States, Asia, and Europe, and can be accessed by consumers within days, with some species such as the prized Bluefin being processed as rapidly as possible to ensure freshness.
Because the fast swimming fish has been heavily harvested, many conservation organizations have sounded warnings about the health of tuna stocks, particularly the southern Bluefin, which is considered to be endangered. Other species are in questionable health as well, with many nations taking large illegal harvests in addition to their internationally agreed upon quota. Tuna catches are declining in numbers, particularly in the Atlantic, where severe restrictions were undertaken in the early 21st century in an attempt to restore stocks of the fish.
Some nations have experimented with tuna farming successfully, and a growing number of the fish for sale is farmed tuna, providing an ecologically sustainable alternative to concerned consumers. Bluefin in particular has proven to be amenable to aquaculture in Australia, suggesting that in addition to providing human food, the farmed fish may be able to replenish depleted wild stocks as well.