THEGREENGROK

Setting Those Turtles Free


by Bill Chameides | October 2nd, 2008
posted by Erica Rowell (Editor)

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Loggerhead sea turtles face a host of threats from low survival rates to over-harvesting and habitat loss. When TS Hanna posed another hazard, volunteers rescued ten of the tiny creatures. (Photo: Dave Johnson and Kim Urian)

On a recent trip to Duke’s Marine Lab in Beaufort, North Carolina, I got a rare, up-close experience of the miracle of life -– I helped launch a clutch of baby loggerhead sea turtles on their trip to the Gulf Stream and points north.

Here’s the story (and backstory), with much of the technical information provided by Catherine McClellan, a graduate student at Duke’s Nicholas School of the Environment.

On summer nights, female loggerhead sea turtles can be found crawling up the beaches of North Carolina to lay their eggs. A turtle will typically lay a clutch of around 120 eggs, which are incubated in the sand for an average of 60 days. When the tiny hatchlings break out of their eggs, they must crawl out of their nest and down the beach, evading predators and obstacles to make it to the sea, where even more threats await.

The Lost Years

The sea turtle’s life at sea is fascinating. Quoting McClellan and her Duke advisor Andy Read, from the paper they co-wrote (published in Biology Letters, Dec. 2007):

“In the western North Atlantic, hatchlings leave their natal beaches, swim offshore and become entrained into the Gulf Stream, eventually inhabiting the oceanic waters of the Atlantic. Their whereabouts during this oceanic phase of life was termed the ‘lost year’ by Archie Carr. … We now know that this lost year actually lasts for more than a decade, during which the turtles remain in oceanic waters.”

Eventually, the turtles make their way back to the western Atlantic and enter our estuaries as juveniles to finish growing up. Adults start the process over again, laying eggs on their natal beaches.

Incredibly, it is estimated that only one turtle in 1,000 survives to adulthood. Combine this minuscule survival rate with over-harvesting and an alarming loss of nesting habitat, and it’s not hard to understand why loggerhead sea turtles are now listed as threatened under the federal Endangered Species Act and endangered by the International Union for Conservation of Nature and Natural Resources.

Recognizing this crisis, a group of researchers has dedicated their careers to the study of loggerheads and, even though the turtles are “born free,” these same scientists lend a helping hand from time to time.

Beachcombing … to Save Sea Turtles

During the summer, volunteers walk North Carolina’s beaches every morning looking for tracks leading to new nests and other evidence of hatchlings-to-be.

These good Samaritans, who are coordinated by the NC Wildlife Resources Commission, provide scientists with data for estimating sea turtle populations (counting nests and hatchlings).

Catherine, in addition to being one of the scientists mining this information to better understand the loggerhead’s life cycle, is also one of the Samaritans lending these sea creatures a helping hand.

During my recent trip to the Marine Lab, I got to play a small role in giving ten tiny hatchlings a second chance. Tropical Storm Hanna had sent large waves over-washing North Carolina’s Kure Beach, exposing would-be hatchlings that were not due for another two weeks.

Fortunately, most of their siblings had made it to the sea, but 10 still had soft shells and exposed yolk sacs, so the volunteers swooped to action, retrieving the eggs from the nest and taking them to NC Fort Fisher Aquarium. They were later transferred to Pine Knoll Shores Aquarium for a few days where better hatchling facilities allowed them to gain some strength and absorb their yolk sacks before heading to the big blue.

On the day I visited the Marine Lab, those ten little turtles hitched a ride offshore with a special crew aboard Duke Marine Laboratory’s 57-foot research vessel the Susan Hudson. We gently picked up each baby turtle one by one, and with its flippers already swimming through the air and its head thrust forward, sent them down a makeshift water slide and into the Atlantic Ocean.

As we watched them swim away with surprisingly sure and strong strokes, a thought crossed my mind -– I wondered if Catherine McClellan was silently making plans to return in 30 or so years to reconnoiter when the females come back to nest on these same beaches.

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