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October 16, 2021

Animal Antics: New tracking methods could help save turtles

By MELANIE HSU | September 27, 2012

While sharks and piranhas have a history of terrorizing the silver screen, their Testudines friends are adored by fans everywhere. The fame (or infamy) of characters like Bowser from the “Mario” series and protagonists of the “Teenage Mutant Ninja Turtles” are signs that turtles have successfully invaded popular culture. Unfortunately, the reality of turtle life is a rather harsh one; many species, such as the loggerhead sea turtle, are struggling to stay off the extinct species list.

Fortunately, a research team from the University of Central Florida, whose study was recently published in the journal PLoS ONE, recently developed a novel tracking technique that could help save these threatened turtles. The technique is designed to link the chemical signatures of the turtles’ diets and their aquatic environments to their migration routes. Amazingly, the technique was found to be just as effective as the comparatively pricier satellite tracking method.

To this day, the loggerhead turtle remains a mystery to the scientific community. The turtles spend 99 percent of their time in the water, returning to the Archie Carr National Wildlife Refuge’s beach to nest every two to three years. This 13-mile-long strip of beach is home to the second largest population of loggerheads in the world; about one of four loggerhead nests in the United States can be found there.

Although other turtles have been expanding along these shoes, the loggerhead population has been declining since 2000. This technique could potentially be used to help wildlife managers preserve the nesting grounds, migration routes and foraging grounds of the loggerheads, all of which are crucial for their survival.

Simona Ceriani, the UCF graduate student who led the study, says that collecting this data is crucial, as it can convince policy makers to delegate what limited conservation funds they have available to protecting the precious loggerheads. After all, it would be sad if the next generation could only read about these lovely animals from a textbook.

To track the turtles, Ceriani took small blood samples from turtles at the refuge and tested for distinct markers, also known as stable isotopes. The turtles were also gifted transmitters, so they could be followed using the already validated, but much more expensive satellite tracking technique. Results showed that the isotope method was as useful as the satellite technique, and had the added benefit of reduced cost.

Daniel R. Evans, a research specialist at the Sea Turtle Conservancy and a co-author of the paper, says that the combination of isotope research with satellite tracking technology has allowed the team to learn exciting information about the loggerheads. By identifying key feeding areas for these turtles, scientists and conservation managers can more effectively direct policies and regulations that could protect turtles in these specific areas.

In addition to validating the tracking technique, the study also discovered that the foraging area for the Florida loggerheads is much larger than previously thought. According to Ceriani, the turtles visit the beach to nest, then travel to a variety of different places, including back north. For the traveling turtles, this beach is a hot attraction.

Using her tracking data, Ceriani found that loggerheads have a diverse set of travel patterns. Some turtles head for the water off the shores of Virginia and Delaware, while others visit the Bahamas and the Gulf of Mexico. Still other turtles decline to visit the beaches of Central Florida. This conflicts with previous beliefs that most of the loggerheads headed south.

Of course, protecting turtle nests on the beach is not nearly enough. In addition, the turtles’ foraging grounds must also be kept safe. Many turtles perish as a result of accidental capture in fishing nets, and still others fall prey to other dangers while they are out at sea.

Interestingly, Florida’s “Sea Turtle Grants Program,” which funded the study, receives its funding from selling the Florida Sea Turtle License Plate.

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