The Hunting Island Mystery Of The Green Turtle

Hunting Island, South Carolina is home to the Loggerhead turtle. Each summer, nature’s circle of life is replayed by female hatchlings born here – who once they reach maturity – return to this coastline to lay their own eggs. From mid-May to August, these majestic marine reptiles maneuver their massive 250-350 pound bodies from the Atlantic Ocean onto the beach where they dig 100-140 nests each season to deposit 100+ eggs per clutch.

While other turtle species are rarely cited on the island, two occurrences of Leatherback turtle eggs were found in 2011 and 2015, according to the logs documented by volunteers of the Hunting Island Sea Turtle Conservation Project.

It’s in the Crawl . . .

Sea Turtles are distinctive by their imprints in the sand. On June 25, 2017 in Zone 2, our mystery began. From some unusual freshly laid tracks, it appeared an alien turtle had paid HI visit.

Upon investigation, Sea Turtle Conservation Project Coordinator Buddy Lawrence speculated this turtle’s flipper-prints might have been the result of an inaugural visit of a ‘Green turtle.’

Lawrence noted in the day’s log: “It looked like a Green sea turtle’s crawl.” His findings were the result of witnessing this species’ nests in Florida, where they are more widely known.

“I am waiting for genetics to confirm, but after seeing Green turtle nest crawls in Garden City ~ I'm 90% of the belief, it’s a Green [versus Loggerhead.] When the genetics confirm it, that will be first documented Green turtle nest on Hunting Island,” added Lawrence.

The major clue that triggered Lawrence’s speculation was identifying the distinctive markers of a Green’s crawl. Differing from a Loggerhead, this turtle’s flippers create straight lines from flipper mark to flipper mark – resulting in a distinct symmetrical pattern. A Loggerhead, on the other hand tracks asymmetrically.

Green Turtle's Crawl

DNA Results

To solve this island mystery, the proof was in the ‘scientific pudding’ sort of speak.The DNA genetic fingerprinting [or what some refer to as CSI for sea turtles] has been used successfully by geneticists for over a decade.

This testing commences when volunteers package a broken or sacrificed egg in a test tube to send off to a laboratory at the University of Georgia.

Turtle Egg Testing

At the lab, they are tested to discover the mother turtle's DNA. This allows researchers to determine where she has nested each season, where she has nested in past years, as well as her species.

Surprisingly, after this particular nest’s eggs were inventoried, the results pointed to “Loggerhead versus Green,” according Beth Glass, one of the day leaders for the Sea Turtle Conservation Project volunteer group.

When asked if a Green and a Loggerhead could have cross-bred to parent this particular clutch of 139 eggs, Glass indicated the DNA “didn’t show a first-generation hybrid.”

But has the mystery really been solved?

The question that remains is whether the eggs that were tested represent 100% of all the eggs in that clutch? Or might crossbreeding still be a consideration? For instance, if first-generation hybrid is not detected in one egg, might first-generation hybrid eggs been found in the eggs that were untested?

By comparison in nature, Siamese cats are able to reproduce blue points, seal points and lilac points all in the same litter. Might not Loggerheads do the same if they crossbred with a Green Turtle?

And if not, how do we resolve that ’symmetrical crawl,’ so typical of a Green and so foreign to a Loggerhead? Might that Green have left her calling card or was a Loggerhead pranking us by assuming the identity of one of her cousins?

Perhaps instead of just the eggs, we need a CSI forensic sleuth to crack this case wide open?

Personally, I’d like to believe that Hunting Island is an equal-opportunity beach, whose shores welcome turtles, no matter what their heritage . . . sort of like the ideals this nation was built upon.  And if one Green turtle was successful in migrating to Hunting Island, might this beach welcome others in years to come? Just another reason to check this destination out for yourself, don’t you think?

 

 

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