The Pacific bluefin tuna is one of three bluefin species found worldwide, including the Atlantic bluefin tuna (Thunnus thynnus) and the Southern bluefin tuna (Thunnus maccoyii). They exhibit high metabolic rates, unique endothermic traits, and extraordinary cardiac performance, making them extremely fast and powerful swimmers able to tolerate both temperate and tropical waters. Prized as a culinary commodity, Pacific bluefin is harvested by many nations and is considered one of the most valuable fish in the ocean. The SWFSC collaborates with many international scientific and management bodies to conduct research on the Pacific bluefin tuna stock, in efforts to manage the fishery and conserve the species.
Of the tunas, Pacific bluefin has the largest geographic range. It spawns in the Western Pacific between central Japan and the northern Philippines and in the Sea of Japan from April through August. While some bluefin spend their entire lives in the Western Pacific, some young fish migrate to the Eastern Pacific.
At about age one, a portion of the population migrate to the Eastern Pacific and start to arrive off the coast of Baja California, Mexico. They remain in the Eastern Pacific for a few years and then migrate back to the Western Pacific Ocean to spawn, a journey taking as little as fifty-five days. Larger adults are rarely found in U.S. waters, which stretches from 3-200 nautical miles offshore.
Information about Pacific Bluefin tuna science and management:
Pacific Bluefin Tuna SWFSC Fact Sheet
Fukushima Radiation in U.S. West Coast Tuna
Pacific Bluefin Close-Kin Mark Recapture Workshop Report (2015)
Pacific Bluefin Tuna Research Coordination Workshop (March 2015)
Pacific Bluefin Tuna Research Activities PFMC presentation (November 2015)
Identification Guide for Pacific bluefin tuna (Thunnus orientalis) and yellowfin tuna (Thunnus albacares) (January 2016)
NOAA FishWatch: Pacific Bluefin Tuna
Pacific Bluefin Tuna FAQs (April 2016)