When it comes to deciphering the clues sea turtles use to navigate the high seas, progress is being made slowly. In 1985, scientists discovered a pocket of magnetite in sea turtles' brains, which led University of North Carolina marine biologist Kenneth Lohmann to study the possibility of a geomagnetic sense in sea turtles. In Lohmann's experiments, he placed loggerhead hatchlings in a large circular tank, and shined a dim light from the east, simulating an east-facing beach, then put out the lights. The hatchlings all continued to swim east, as expected. The turtles began swimming west, indicating they sensed the change in the magnetic pole.
Olfaction also appears to play a role in helping the turtles find their way.
Most sea turtles, like salmon, are thought to return to their natal beaches when they nest. Scientists theorize that they use their keen sense of smell to home in on the beach when they return, as each beach, with its distinct mineral composition, has a slightly different odor. Whether female sea turtles actually do lay their eggs at the beach where they hatched puzzled Archie Carr. Today, the answer lies within Peter Dutton's grasp. Peter is creating a massive database of turtle nesting beaches and their accompanying genetic signatures.