Tuna and tuna-like species are very important economically and a significant source of food. They include approximately forty species occurring in the Atlantic, Indian and Pacific Oceans and in the Mediterranean Sea. Their annual global production has tended to increase continuously from less than 0.6 million tonnes in 1950 to almost 6.6 million tonnes.

The so-called principal market tuna species are most important among the tuna and tuna-like species from the catch weight and economical view points. They are landed in numerous locations around the world, traded on the nearly global scale and also processed and consumed in many locations worldwide.

Taxonomy, ecology and general importance

In taxonomy, tuna and tuna-like species are defined as the suborder of Scombroidei. They are composed of tunas (sometimes referred as true tunas), billfishes and other tuna-like species. The species include the largest and fastest fish in the sea.

Among the tunas (Thunnini), there are very commercially very important species (frequently referred to as the principal market tuna species). They include (ordered by catch weight): skipjack, yellowfin, bigeye, albacore and three species of bluefin. The first three species are tropical and the remainder are temperate. The principal market species are widely distributed in the Atlantic, Indian and Pacific Oceans. Fish of one species (southern bluefin tuna) migrate among all the Oceans. Most other species constitute different stocks in the different Oceans. The principal market tunas are subject of intensive international trade for canning and sashimi on the global scale.

With the exception of two species (Mediterranean and roundscale spearfish), the billfishes have also wide distributions in the Atlantic, Indian and Pacific Oceans. They are of great importance to game fishing. One billfish species (swordfish) is a target of commercial fisheries.

The principal market tunas and billfishes are of great economic importance to many both developed and developing countries.

The tuna and tuna-like species other than the principal market species and billfishes have more narrow distribution, frequently limited to water masses over the continental shelf. Therefore, some of them are referred to as neritic species. They are presently of importance to mostly developing countries, being subject of mostly artisanal and recreational fisheries. From the tuna and tuna-like species, the 1982 UN Convention on the Law of the Sea classifies the principal market tunas, billfishes, blackfin, bullet and frigate tuna, little tunny and kawakawa as highly migratory regardless that particularly the last two species are mostly neritic.

Stock status

Present status

Most tropical principal market tunas have reacted well to exploitation because of their high fecundity, a relatively short life span, wide geographic distribution and opportunistic behaviour make them highly productive. The tropical species of skipjack and yellowfin are used mostly for canning. Because of that, they fetch lower prices than the tunas used for sashimi such as bluefin and bigeye (bigeye is tropical species).

The most up-to-date review of the state of global Tuna and Tuna like resources is available in the Fishery Resources Monitoring System (FIRMS): Tuna and tuna-like species - Global

Stocks of temperate species (albacore and bluefins) are less productive and may be more susceptible to overexploitation. Some bluefin species (used for expensive sashimi) are, in fact, significantly depleted, which is a prime conservation problem. The albacore used mainly for canning fetches much lower prices than bluefin, but higher than skipjack and yellowfin.

Most stocks of the principal market tunas are about fully exploited. A significant number of stocks are overexploited or depleted. There are still few stocks of the principal market tunas that are moderately exploited.

Outlook

If tuna fisheries continue to be profitable, the intensity of fishing may even increase as a result of fishing overcapacity unless it is effectively restrained by fisheries management measures. Such intensification would result in a significant deterioration in the status of stocks of tuna and tuna-like species. Even without the intensification, the status of some stocks that are presently being overexploited is likely to deteriorate unless the exploitation is reduced. This deterioration could eventually lead to a reduction in catches.

Other involved institutions

In addition to the above-mentioned information, websites of the tuna fishery bodies and other international and national institutions have a lot of information on the species, particularly on regional scales. Tuna-org is as an informal framework for sharing information from the tuna bodies listed below.

• (no link available)
• Inter-American Tropical Tuna Commission (IATTC)
• International Commission for the Conservation of Atlantic Tuna (ICCAT)
• Indian Ocean Tuna Commission (IOTC)
• Western and Central Pacific Fisheries Commission (WCPFC)

The websites of the Oceanic Fisheries Programme (OFP) and the Pacific Islands Forum Fisheries Agency (FFA) contain additional information on the species in the western and central Pacific. Atuna is the gateway to the global tuna business and provides its customers with continuously updated tuna market news and information.