When green turtles toddle out to the ocean after hatching from eggs at sandy beaches they more or less disappear from view and aren't seen again for several years until they show up as juveniles at coastal foraging areas.
Researchers from Oregon State University and the City University of New York used sophisticated ocean circulation models to trace the likely route of baby green turtles from known nesting sites once they entered the water. They also identified known locations of foraging sites where the turtles reappeared as juveniles, and went backwards – tracing where they most likely arrived via currents.
The researchers simulated the dispersal of turtles from each of 29 separate locations in portions of the southern Caribbean, the Sargasso Sea, and portions of the South Atlantic Ocean and the West Indian Ocean and identified "hot spots" throughout these basins where computer models suggest that virtual turtles would be densely aggregated. They estimate the fewest number of turtles would be located in the open ocean along the equator between South America and central Africa.
Based on the models, it appears that turtles from many populations would circumnavigate the Atlantic Ocean basin. "Backtracking" simulations revealed that numerous foraging grounds were predicted to have turtles arrive from the North Atlantic, South Atlantic and Southwest Indian oceans. Thus, a high degree of connectivity among populations appears likely based on circulation patterns at the ocean surface.
The next step in the research might be for turtle biologists throughout the Atlantic Ocean basin to "ground truth" the model by looking for young turtles in those hotspots. Knowing more about their early life history and migration routes could help in managing the population, he said.