Cumberland Island’s Ancient Mariner. The Legendary Loggerhead Sea Turtle.
Silvery reflections of a nearly full moon frost the inky darkness of the waters surrounding Georgia’s largest barrier island. The eerie quiet is suddenly broken by a soft splash through which emerges a creature whose species has survived what the dinosaurs could not. The majestic loggerhead sea turtle lumbers forward. Her extraordinary gracefulness as a swimmer gives way to a laboring awkwardness as her giant flippers pull her slowly onto the sand. After 35 years, she has returned to her birthplace, Cumberland Island, to give life to her own offspring.
Loggerhead sea turtles existed before the time of dinosaurs. They survived the breaking up and drifting of continents, the
creation of new oceans, ice ages, catastrophic volcanoes, and even the asteroid impact that contributed to the demise of the dinosaurs. It remains to be seen, however, if they will survive the ravishes of man.
Nationally, the loggerhead sea turtle carries a “threatened” designation, meaning they are likely to become in danger of extinction within the foreseeable future. Internationally, they are already listed as “endangered.” Based on nesting beach monitoring reports and publications, there is an estimated population of 44,560 nesting females. With its dedicated nesting monitoring on Cumberland Island and the recent establishment of the Georgia Sea Turtle Center on Jekyll Island, Coastal Georgia plays an important role in the propagation of the species.
According to Doug Hoffman, biologist for Cumberland Island National Seashore, the National Park Service employs three interns from the Student Conservation Association to monitor the sea turtle nests each season. Patrolling the seventeen miles of Cumberland Island’s pristine shoreline, interns look for “crawls” that indicate a mother turtle’s tracks to a nest. They follow the crawl to the sand dunes to find the body pit (where the mother has made her nest). Then, after locating the egg chamber, they dig down just deep enough to confirm there are eggs in the chamber. They then replace the sand, note the GPS reading,
mark the nest with a numbered stake, and cover the area with a screen to keep armadillos, raccoons, and feral hogs from disturbing the nest. The incubation process lasts approximately 60 days. The interns intensely monitor a nest after 50 days, checking for hatchlings each morning. After the hatchlings leave the nest, the interns “excavate” the nest, record data on hatching success, and remove any unhatched eggs, then bury the remains in the dunes so predatory animals do not associate the site with feeding.
The female loggerhead may lay four to seven nests per season, approximately 12 to 14 days apart with average lays of 100 to 126 eggs in each nest. Unfortunately, as few as one in a thousand hatched loggerheads actually reach adulthood. The human impact on this threatened species is significant and includes incidental capture in shrimp trawling, crab and lobster pots, water pollution with foreign objects like plastic bags that are ingested by the turtles, even fishermen’s long lines and cables. Coastal development has also made an impact as fewer and fewer suitable nesting areas are available for the mothers to come home to. And manmade lights onshore confuse the hatchlings—that navigate by the moon—causing them to turn landward rather than seaward.
Driven by mysterious forces, it is an amazing journey that the loggerhead mothers make, some traveling as far as 1400 miles. (Unless they are injured, male loggerheads never come back to land once they reach the ocean.) Hatchlings fortunate enough to make it to the water will swim nonstop for days. Once in the ocean’s current, they circle the ocean for the first 8-12 years of their lives. After an additional 20-25 years foraging in the relatively shallow coastal waters of the Southeastern United States, female loggerheads will return to the area where they were born to deposit their eggs. And the cycle begins again.
Georgia’s 2007 loggerhead nesting season was launched in early May when the first nest of the season was discovered on Cumberland Island. While recent years have seen as many as 1400 loggerhead nests on Georgia beaches, experts forecast a below average nesting activity this year—approximately 500-800 nests in Georgia. It is not atypical for Cumberland Island to have the most
documented nests in a given year. And though five species of sea turtles are found in waters off the Georgia coast, loggerheads are the only species to routinely nest on the state’s beaches.
From May to mid-August, the female turtles make their journey home to nest in Georgia. Some weighing as much as 350 pounds, the turtles often have barnacles and algae growing on their shell—a virtual ecosystem living right on their back—a biologist’s delight.
With the recent opening of the Georgia Sea Turtle Center on Jekyll Island just a few minutes north of St. Marys, regional biologists will have an even greater advantage in studying the ancient reptile. “Having the center here will make a huge difference,” said Cumberland Island National Seashore’s Hoffman.
Each year, about a dozen loggerheads wash ashore in Georgia—alive but sick or injured and needing attention. Even before its official opening in June, the Georgia Sea Turtle Center already had three patients—one from Cumberland Island. Dr. Bill Irwin, the center’s director, told the story.
“We got the call from our colleagues on Cumberland telling us that an injured loggerhead had washed ashore. Two of our staff went down and picked him up. He was badly wounded, apparently struck on the head by the skeg of a small boat. The wound was a week or so old, and his condition was such that we had little hope at first.” But, according to Dr. Irwin, after treatment and tube feeding, Nick (their name for the unfortunate leviathan) began to come around. Though the center has on-premises x-ray capabilities, at time of publishing, Dr. Irwin was seeking the help of local hospitals to perform a catscan to determine prognosis and continued treatment. “He’s getting a little feistier,” said Dr. Irwin.
Prior to the Jekyll Island center opening, loggerheads like Nick had to be transported to Florida or South Carolina for care and release. With the opening of the center, not only will
rescue be close by for those in need, but an exciting showcase of healthy loggerheads can be viewed by the public as well. Live sea turtles will be on display, including several hatchlings, each year in an exhibit simulating their early life in beds of floating sargassum seaweed offshore. The 7300 square-foot center includes both indoor and outdoor exhibits.
Loggerhead sea turtles—there is something quite magical about these ancient mariners who often live 80 years or longer. They are the bridge that links ocean to earth. They know things which we will never know. And they have seen things which we will never see. The next time you catch the soft glint of
moonlight bouncing off our coastal waters on a warm summer’s eve, think of their siren song and the amazing
journey they make to fulfill their legacy that began millions of years ago.
For information on the Georgia
Sea Turtle Center, visit
www.georgiaseaturtlecenter.org
or call 912-635-4444.
