Baby Sea Turtles: Are They Really Lost at Sea?
By Savanna Fitzgerald | December 04, 2012 2:58 PM
Imagine waking up one day surrounded by large, hostile, flying creatures and you have to escape a vast sand desert with your brothers and sisters. You have no parents, no map, and no previous experience of the land. If you make it across the desert, you will have to navigate 9000 miles through turbulent water and more dangerous creatures to a place you have never been. This is the daunting, nearly impossible quest every single baby sea turtle must undergo upon hatching. Recent research at UNC Chapel-Hill by Professor Kenneth Lohmann proved that weak baby turtles can swim against currents enough to significantly better their chances of reaching a safe haven.
Loggerhead turtles all have the ability to navigate ocean waters using the Earth’s magnetic pull, much like a compass. This navigation method allows these turtles to stick to their traditional migration paths and swim in the correct direction. Scientists once thought ocean current direction was the deciding factor in where a baby turtle went in the ocean due to the baby turtle’s lack of strength. Lohmann’s new study suggests that what very little navigational swimming these young Loggerheads can do makes a big difference in determining their destination and survival.
The 9,000 miles baby turtles traverse is never in a straight line but rather a circular motion. Baby turtles are pushed by the Atlantic Ocean’s currents before reaching their final destination
Where a baby turtle drifts to in the ocean has a huge impact on its chances of survival. Certain parts of the Atlantic Ocean are full of predators or fall to dangerously low temperatures, making it an extremely risky area for baby turtles. Using their internal compass, baby turtles supposedly avoid these danger zones and can tilt their path of travel towards safer, more beneficial areas with plenty of food and warmth. To test this theory, Lohmann decided to use a program that would simulate ocean currents and the earth’s magnetic field. Then, his research team introduced four different data groups in the computer simulation representing baby turtles: one group designed to drift passively with the currents and three other groups designed to follow their magnetic compass at varying degrees against the currents.
The results of the simulation showed that baby turtles that swam a mere one to three hours a day against the currents had a much higher chance of ending up in safe waters compared to their passively drifting counterparts. This relatively small behavioral shift makes a big difference, proving that the Loggerhead turtle’s magnetic navigation is more important to survival than previously believed. This finding may even extend to other small, weak-swimming ocean creatures that use magnetic navigation such as baby eels. We have underestimated small marine creatures; following a compass to any length rather than relying entirely on currents is proving to be the difference between life and death in the ocean.
Out of necessity, sea turtles developed and perfected the magnetic compass long before humans even began thinking about navigating oceans. Through study and understanding of Earth’s creatures and processes, we can harness their strategies to invent new technology or improve upon existing innovations. This study of sea turtles could easily lead to the improvement of oceanic vessels and their navigation systems such as those on ships and submarines. As proven by the study, baby sea turtles do not need much energy to cross large spans of ocean and still arrive at the correct location; this can be applied to general oceanic navigation. In this case we could slash energy expenditure and fuel usage in favor of a more magnetic oriented ocean travel system. For answers to important engineering or innovation problems, there is first and foremost the world around us and the creatures we share it with.
Further Reading:
Orientation and swimming behavior of hatchling loggerhead turtles
Questions About Incredible Sea Turtle Migration Answered by Scientists