Sir David Attenborough narrates this fascinating documentary following marine biologist and wildlife photographer Rick Rosenthal as he uncovers the life of the Bluefin Tuna, a creature few have managed to film in the wild. Bluefin are the largest tunas and can live up to 40 years. Made for speed and built like torpedoes, they migrate across all oceans and can dive deeper than 3,000 feet. However, overfishing has led to the Bluefin becoming endangered.