Where Tuna Go: Atlantic fish mix for feeding, not spawning
By Susan Milius
The largest high-tech tag study yet of Atlantic bluefin tuna suggests that two groups mix on feeding grounds but spawn on opposite sides of the ocean. This finding indicates that fishing regulations need to change, say the researchers who tagged and tracked hundreds of the fish.
Bluefin tuna counts in the western Atlantic plummeted decades ago and haven’t recovered, despite conservation measures, says Barbara Block of Stanford University. Estimates are that 25,000 fish remain. Block and her colleagues say that their new evidence supports the idea that tuna populations travel widely but spawn only at the edge of the continental shelf in the Gulf of Mexico or at a site in the Mediterranean Sea.