Researchers have a new understanding about the migration of loggerhead sea turtles, thanks to satellite tagging and the largest dataset of its kind, CBC Radio reports. North Pacific loggerhead sea turtles breed on the beaches of Japan. Once they hatch, the turtles disappear into the ocean for decades before returning to breed. Some scientists referred to this as their “lost years”. “For a long time we’ve known that the loggerhead sea turtles are on both sides of the Pacific,” said marine scientist Dana Briscoe. “But we thought that there were two entirely separate, distinct populations because it seemed unimaginable that such a small creature could cross an entire ocean basin that’s greater than 9,000 kilometres in distance.” By tagging 200 sea turtles and tracking them for 15 years, the team was able to confirm that they are from the same population.