Barnacle analysis reveals sea turtle migration routes

A groundbreaking technique developed by South Korean researchers allows scientists to reconstruct the migration paths of sea turtles by analyzing barnacles attached to their shells. This innovative method offers a new way to understand the movements of these marine creatures, overcoming limitations of traditional tracking methods.

The research team, led by Professor Kim Tae-won of Inha University's Department of Ocean Science, utilized the fact that barnacle shells store environmental information, such as water temperature and salinity, as they grow. These layers within the barnacle shell act like tree rings, recording the turtle's journey over time. "The barnacle shell records the marine environmental information experienced by the host during its movement," explained Jo Kyung-sik, the paper's lead author.

“

The barnacle shell records the marine environmental information experienced by the host during its movement.

Through high-resolution stable isotope analysis of barnacles collected from a loggerhead sea turtle found in Jeju Island, the researchers determined its 18-month journey. The turtle traveled through the Taiwan Strait, the waters around the Philippines, and the Ryukyu Islands before reaching the waters near Jeju Island.

Further analysis of other loggerhead and hawksbill sea turtles revealed that loggerheads repeatedly undertake long-distance migrations between the Philippines and Jeju waters. Hawksbill turtles, on the other hand, were found to move northward along the Ryukyu Islands. This technique is particularly valuable for countries like South Korea, where directly tracking sea turtles can be challenging due to factors like limited nesting sites and reliance on stranded or bycaught individuals.

“

It is significant that we can reconstruct migration paths using only stranded individuals, even in regions like Korea where direct tracking of sea turtles is difficult.