Sea Turtles

In the spring and early summer, female loggerhead sea turtles come ashore to nest on southeastern U.S. beaches from North Carolina to Florida. The turtles, weighing as much as 350 pounds, emerge from the foamy surf after the sun sets orange on the horizon, and slowly labor up the beach toward the dunes.

The solitary loggerheads return to the same beach three or four times during the summer. At the end of their crawl, which looks a lot like tire tracks that end above the high tide line, the mother turtle clears away the soft sand and spends several hours digging a nest with her hind flippers. Into a nest, which is 20 inches deep and shaped like a light bulb, she drops about 110 ping-pong ball sized eggs with soft leathery white shells. Then, flinging sand in all directions, the mother turtle covers the nest and heads back to the moonlit ocean, never to see this nest or these eggs again. The eggs and the turtles inside are now on their own.

On their own, that is, except for the local sea turtle patrols. Every morning, when the sun is still a pink ball on the horizon, these volunteers comb the beaches looking for crawls that lead to loggerhead nests. Excitement runs high when loggerhead tracks are found! By studying the tracks and probing in the sand with special t-shaped turtle probes, the trained volunteers can usually locate the nest. The volunteers mark the nest with a special orange sign and note the date. A protective mesh screen is centered over the nest to prevent predators like raccoons, foxes, and ghost crabs from raiding the eggs.

For approximately 60 days, the eggs will incubate in the warm sand. At about day 30, an amazing event takes place. Depending on where the eggs are in the chamber and how hot or cool the weather has been determines the sex of the hatchlings. Warmer temperatures produce females and cooler ones produce males! The warmer the temperature, the sooner the nest will hatch.

Amazingly, because the embryos inside the eggs move around, and the eggs bump each other, the turtles all develop at the same rate, and all hatch at about the same time! The hatchlings rip open the shell with an egg tooth at the end of their beak. For a couple days, they rest, and absorb the yolk sac attached to their plastron or lower shell. Their upper shell or carapace straightens out and hardens a bit.

Above the nest, on the beach, turtle patrol members, checking the nest, see a small bowl shaped indentation in the sand. The turtles are starting to dig! As they dig, some of the sand sifts down. The hatchlings are ready to “boil” from the nest!

What an incredible sight! As many as 140 hatchlings were seen boiling from this nest on Seabrook Island, South Carolina. Miraculously these hatchlings climbed from the nest, scrambled through the ups and downs of the dunes, and scrabbled over the wet sand, to the warm waiting ocean. The bright light of the moon and the glimmering waters guided the hatchlings to the safety of the sea.

As the hatchlings scurried to the ocean as quickly as possible to avoid being picked off by seabirds and ghost crabs, their flippers became stronger and stronger, readying the turtles for the long 24-48 hour swim ahead of them.

Only 1 in 1,000 loggerhead hatchlings will reach breeding age.

Swimming away from the southeast U.S. coast, using wave direction in the water and the earth’s magnetic field, the young turtles finally find refuge in the North Atlantic gyre and the Sargasso Sea, where they remain for the next 10 years. These young loggerheads travel as far away as the Canary Islands, Madeira, and the western end of the Mediterranean Sea.

Finding refuge at convergence zones where the ocean currents come together, the juvenile loggerheads float in vast sargassum mats camouflaged from predators. The golden sargassum is filled with floating vegetation which attracts small crabs that the turtles eat.

When they are nearly 20 inches long and 7-12 years old, the young turtles return to live in the U.S. coastal waters. They comb the bottoms of the near-shore waters consuming jellyfish and barnacles. Unfortunately they sometimes ingest floating plastic bags and balloons which look like jellyfish to the hungry turtles. Ingesting these and other plastic litter can be deadly to the sea turtles.  The turtles are also prone to being captured in the shrimp or fish nets of ocean-going trawlers. When caught in these nets, the turtles drown.

The loggerheads also venture into shallow shelf waters where they feed on crabs and mollusks, moon snails, sea quirts, even sea cucumbers. Opportunistic eaters, the turtles shift their diet in relation to their location and amount of prey. In shallow waters, however, the young turtles sometimes get tangled in crab trap lines or get hooked by nearby fisherman.

As you can see, from the moment sea turtles eggs are dropped into their nest in the dunes, they are in danger. When they hatch, bright lights from the houses, streetlights, and even flashlights confuse them and lead them away from the ocean where they cannot survive. As the turtles forage for food in the ocean, fishing trawlers, shrimpers, fish hooks, boat strikes, crab trap lines, and plastic debris floating in the water can kill the sea turtles.

Planet Protectors like the South Carolina Aquarium Sea Turtle Hospital are there to rescue sick or injured sea turtles. The staff works work hard to protect and rehabilitate these magnificent marine animals, and to educate the public. We visited the SCA Sea Turtle Hospital and were lucky enough to go on a behind-the-scenes tour with Kelly Thorvalson, Senior Biologist and Sea Turtle Program Rescue Coordinator.

Sea turtles that are rescued and brought to the SCA Turtle Hospital are treated using a variety of medical procedures. These include administering drugs and performing surgeries, as well as taking x-rays and ultra-sounds.  The costs can be staggering. Antibiotics alone for one sea turtle can be over fifty dollars a day. The average stay for a sea turtle at the South Carolina Aquarium now 6 months. And all of this medical and husbandry care is paid for by donations to the hospital.

Throughout each sea turtle’s rehabilitation, The SCA sea turtle rescue staff weighs and measures the turtle to monitor its growth. When it is well enough, a rehabilitated sea turtle, like “Folly” a Kemp’s Ridley, is returned to its natural habitat where it can rejoin the breeding population, and help ensure that sea turtles will continue to be with us for generations to come.

Since its inception, the Aquarium has released over 20 rehabilitated sea turtles. Some of the turtles are satellite-tagged to track their travels through the ocean.  Two of loggerheads currently in the hospital, Cape Romain and Edisto, are males. They will be tagged before release. It is rare for male sea turtles to be treated at the hospital because these turtles do not come inshore to nest as the females do. By tagging Cape Romain and Edisto, biologists hope to learn much more about the male sea turtles and their range throughout the ocean waters. The more they learn,about the sea turtles’ habits, the better they can protect them.

When you visit our Planet Protector, the South Carolina Aquarium, you will be instructed and assisted by some of the over 300 volunteers that staff the aquarium each day. Take the time to speak with them and ask questions about the exhibits. And learn how you, like them, can be a Planet Protector.

Remember, we share the beach and the oceans with sea turtles and many other marine animals. What we do has a direct effect on their lives. Let’s not lose the loggerheads or any other sea turtles. Take the time to learn about them and to offer your help. After all, it’s their planet too!