A new study finds that loggerhead sea turtles that nest on beaches with similar magnetic fields are also genetically similar to one another.
Researchers have previously observed that loggerhead turtles return as adults to nest on the same beaches where they were hatched. This happens even after migrating across miles and miles of oceans because they were guided by magnetic fields. The biologists call this occurrence as natal homing.
Now, a new study from the biologists of the University of North Carolina at Chapel Hill suggests that there are turtles that get lost along the way and end up in a different beach that is not their natal home.
Despite being lost, however, they would always find fellow turtles with genetic composition akin to them.
This is because as they use the magnetic field to track their way back home, they can mistakenly detect a beach with the same makeup of currents and magnetized materials to that of their birthplace.
North Carolina Loggerhead Sea Turtles
The new observation is particularly true among loggerhead sea turtles that are hatched on North Carolina beaches. UNC-Chapel Hill biologists Kenneth J. Lohmann and J. Roger Brothers say that after migrating across the entire Atlantic Ocean basin when they were still babies, these turtles return home on North Carolina beaches or for some as far as the opposite coast of Florida.
Whether its North Carolina or Florida beaches, two important factors remain consistent: the turtles' similar genetic composition and the kind of magnetic field found on the beach.
Lohman and Brothers highlight that their finding still failed to determine precisely the exact magnetic parameters that turtles use in tracking down their natal beaches.
Their new finding is significant in the conservation of sea turtles and other migratory animals such as salmon, sharks, and birds. Specifically, since magnetic fields are important for turtles in finding their homes, the sea walls, power lines, and large beachfront buildings should be highly regulated along shores. This infrastructure interferes with a location's magnetic field.
Loggerhead Sea Turtles Facts
The loggerhead sea turtles are already listed as "threatened" animals. This means that they are likely to become endangered within the foreseeable future under the U.S. Federal Endangered Species Act. In international level, they are already listed as endangered species according to the Sea Turtle Conservancy.
The greatest threat to loggerheads is the loss of nesting habitat due to coastal development and human disturbances. Other threats are longline fishing, shrimp trawling, and pollution that they may encounter while migrating.