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Sea Turtles Finding their Way Back Home

It is safe to say that many people get lost without a GPS system in their car, or a map
in their hands. However, unlike humans sea turtles can navigate their way back
home without relying on devices like these.
Sea turtles are able to locate the area in which they were born using magnetic fields.

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Swim turtles use geomagnetic imprinting to return to where they were born. Photo courtesy of National Geographic.

Through a process known as geomagnetic imprinting, turtles were observed to have
learned their home beach’s distinct magnetic signature. A study was conducted with
loggerhead turtles, in which using geomagnetic imprinting, were able to find their
way back home within a 40 to 50 mile radius.
Kenneth Lohmann, a professor at the University of North Carolina, states “This is
vital information if you want to restore sea turtles to areas where they once lived
before being hunted to extinction”. The most impressive fact is that most turtles
leave their home beach very young. For instance, they swim thousands of miles from
their birth beach in North Carolina to somewhere in North Africa. After swimming
thousands of miles in an open ocean, they still manage to find their way back.
Turtles are able to recognize the magnetic field’s intensity and its inclination angle
(the angle between the equatorial plane of earth and orbital plane of the satellite).
Due to researcher’s disbeliefs, it was determined that turtles that nest on beaches
with similar magnetic signatures were genetically more similar than other turtles
that just lived on nearby beaches. One explanation for this phenomenon is that
individual turtles might make a slight navigational error and nest on beaches that
are magnetically similar to their own.
Dr. Lohmann has said that the experiment is based solely on genetic data, and not
actual experimental evidence, which would be very difficult to achieve in a more
complex study. Even without the physical verification, the information conducted is
still useful according to Nathan Putman, a senior scientist at LGL Ecological
Research Associates Inc. Knowing this information provides scientists with a new
outlook on the conservation of turtles back to their home land.
By: JoAnna Palumbo’19, Staff Writer

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