Bluefin Tuna; gold from the ocean As one of the most valuable fish in the world, it’s not surprising that the Atlantic Bluefin Tuna has been overfished. As a result it is considered an endangered specie by the IUCN, and its fishing in the Mediterranean is allowed only one month per year, from May 15 to June 15. Imagine hauling in a Atlantic Bluefin Tuna weighing 1000 kilograms. That’s the world record for a Blue Fin caught off the coast of Nova Scotia. More commonly, the tunas weigh about 250 kg. and average 2 to 2.5 meters in length. Commercial fishing boats must have special permits to catch the highly-prized species and observe specific limits. The Japanese buy nearly 90% of blue fin caught in the Mediterranean.The tuna are caught in huge nets and kept alive on fish farms for approximately six months. During that period they feast on sardines until they are killed and sold.