30 thousand. Bluefin tuna is a relatively large tuna, one of which can reach 694 kilograms. However, facing the consumption of so many people all over the world, it has become an extremely endangered species. By the end of 20221February 18, there were 30,000 bluefin tuna in the world, and Atlantic bluefin tuna was an pelagic migratory fish. It can withstand a considerable temperature range, living above and below the thermocline, and the depth is over 9850 meters. Get married and swim fast. Atlantic bluefin tuna showed a strong group swimming habit when it was young.