The red meat of the blue fin tuna is very rich, nutritious and very tender. That’s why it’s considered a delicacy in Japan and other countries. But nature conservation organization such as the World Wildlife Fund fear that the fish is on the brink of extinction. The blue fin is already on the "Red List of Threatened Species" published by the International Union for the Conservation of Nature, the IUCN. Experts say illegal overfishing is what has put it there.