Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Thunnus orientalis, commonly known as Pacific bluefin tuna, is one of the largest and fastest species of tuna found across the Pacific Ocean, reaching up to 540kg and a maximum length of 3m. Today, bluefin tuna is estimated to be severely overfished, due to its nutritive properties and high value. A new study led by US scientists has showed elevated levels of radioactive cesium in bluefin tuna caught off the California coast that migrated from waters off Japan. Learn more about the Pacific bluefin tuna in this book.