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Marine Animal Encyclopedia

Northern Bluefin Tuna Thunnus thynnus

The northern bluefin tuna is one of the world’s most valuable commercial fish and is heavily overexploited. Like mackerel, it is designed for high-speed swimming and is one of the fastest bony fish, attaining speeds of at least 43 mph (70 km/h).

The pectoral, pelvic, and first dorsal fins can be slotted into grooves to further streamline the torpedo-shaped body. To provide for long-distance, sustained swimming, the fish has large amounts of red muscle, which has a high fat content and can store oxygen. Other, similar species of bluefin tuna occur in the Pacific Ocean and southern parts of the Atlantic Ocean.

Threats

Western Atlantic bluefin tuna have been reduced by more than 82 percent. The International Commission for the Conservation of Atlantic Tunas (ICCAT) estimates that as few as 25,000 individual mature tuna tons of mature bluefin tuna remain.

Overfishing, loss of their prey and tuna ranching all threaten bluefin tuna.

What Oceana Does

In the U.S., Oceana has pushed for action by NOAA Fisheries to establish a time/area closure in the Gulf of Mexico to end the incidental taking of spawning-age bluefin tuna before they spawn.

In Europe, Oceana has been pushing for protections of the second known bluefin tuna spawning ground, the Mediterranean Sea.

Oceana has urged the International Commission for the Conservation of Atlantic Tunas (ICCAT) to enact immediate fisheries closures until stocks recover, protect spawning bluefin, reduce fishing capacity and reduce the number of tuna ranching operations in the Mediterranean.

Northern Bluefin Tunazoom image
Northern Bluefin Tunazoom image
Northern Bluefin Tunazoom image
Northern Bluefin Tunazoom image
Northern Bluefin Tunazoom image
  • Order Perciformes
  • Length Up to 15 ft (4.5 m)
  • Weight Up to 2,230 lb (680 kg)
  • Depth 0–9,900 ft (0–3,000 m)
  • Distribution Northern and central Atlantic and Mediterranean
Northern Bluefin Tuna habitat mapzoom image