There are two populations of Atlantic bluefin tuna: a smaller western population which spawns in the Gulf of Mexico, and a larger eastern population which spawns in the Mediterranean Sea.
These two populations are not completely separate, however. Adults and juveniles from both populations feed together, particularly off the east coast of North America and in the central Atlantic. But come spawning season, adults always return to the waters in which they hatched.
Map: Geographical distribution of Atlantic bluefin tuna
Map: Geographical distribution of Atlantic bluefin tuna
