Friday, May 8, 2009

Story One: Chelonia mydas

It is late November, and the rising full moon can be seen in the day-lit sky. A newly matured green sea turtle is swimming through the shallow ocean waters off the coast of the beach where she was born. She has not returned to this site since she and her siblings dug their way up through the warm sand of the nest their mother dug for them. The last time she touched land, the hatchling and her siblings had scurried upwards out of the nest, towards the surface, breathing between the sand grains. They reached the surface of the nest with a burst of energy, as a coordinated group, but they dispersed as they clambered toward the surf. It was the last time she saw many of her siblings, as stragglers were taken by beach-dwelling crabs, popping up from their holes to capture the struggling hatchlings by the moonlight. Others were captured by shore-birds, night herons hiding still in the night, long legs poised to run toward their prey at the opportune moment.

Most of the hatchlings made it into the ocean. As soon as they reached the salty water, they swam, frenzied, past the breakers. They put every ounce of their energy into swimming that first night. Fish, small sharks, and cuttlefish took some of the hatchlings for their own meals, but the rest kept swimming. Separated, they swam for days. The residual yolk in their bodies supplied enough energy for them to continue swimming without feeding for several days, and they used this energy until they reached the currents that carried them to the deep, open ocean.

The green turtle hatchling drifted with the ocean currents, eating plankton near the surface of the water, and slowly growing. Her carapace grew from five centimeters to forty centimeters during her life in the open ocean, and when she was large enough to return to shallower waters without risking predation, she swam toward the sea-grass pastures. Here, she continued feeding for many years. As a youth, she was not selective in her diet, feeding on sponges, jellyfish, macroalgae, and even cigarette butts washed out to sea, floating on the surface of the water. But as she grew and matured, she recognized the strength and energy that feeding on the sea-grass beds provided her. With her serrated beak, she could easily seize and break off pieces of sea-grass. She thrived in large sea-grass meadows, where green sea-grass, brown at the tips, covered the shallow banks and sand-bottom channels of the coastal waters. She continued to supplement her diet with small amounts of macroalgae, and her herbivorous meals created the green body fat she is named for.

Now, she is nearly forty years old. After feeding and growing for so many years, she is ready to breed. She migrated hundreds of kilometers from her feeding grounds to the area of the nesting beach where she was born. There, she mated with several male turtles who had also migrated to the breeding grounds. The males, with claws at the tips of their flippers, held on to the female’s carapace as they mated.

Though it is several weeks after her first mating, she still carries the claw marks of the males on her shell. She made her first journey to the beach nearly two weeks ago. After dark, she swam to shore and lumbered up the gradient of the beach. She used her front flippers to drag her body over the sand. With her fore and rear flippers, she excavated her first nest area, and with her rear flippers, she dug her first egg chamber, alternately scooping the sand. When it was deep enough, she laid over one hundred small, round eggs, leathery and white against the tawny sand. She used her rear flippers again to fill and cover the egg chamber. As she laid her eggs, glands near her eyes formed tears, excreting the excess salt from the seawater she drank. Though these tears are constantly sliding down her face, they are most noticeable now that she has left the ocean for the land. She blinked, letting the tears go, turned, and followed the moonlight back to the dark sea.

If the turtle has concealed her nest sufficiently, it will protect the eggs from feral pigs and dogs that come to the beach for a late night snack. After eight weeks, the turtles inside the eggs will begin to pip, breaking their eggshells by rubbing an egg tooth on the tip of their noses against the shells. Each hatchling will pip within a few hours of each another, and they will stay within their broken eggshells for several days as their soft bodies uncurl. Once they have straightened, they will emerge from their nest, the same way their mother did so many years ago. They will race to the ocean, the darkness of their shells protecting their bodies in the dangerous night. Once in the water, their white undersides will protect them from predators below, looking toward the sky for the silhouettes of prey.

Now, the green sea turtle swims through the sea water, parallel to her nesting beach. After the sun goes down, when the moon is bright in the dark sky, she will make her way to the silent beach. She will trudge to the perfect nesting spot and dig an egg chamber, and she will quietly lay her second clutch of eggs. She will have nothing to do with her eggs once they have been laid; she will never see her offspring emerge from the nest or make their way to the ocean. Not all of them will survive. Most will make it safely to the sea, and some of the lucky ones will survive attacks by sharks and other marine predators. The ones that survive and make it to the open ocean will carefully grow over many years, feeding on algae and sea grasses like their mother did. Some will make it to breeding age, joining in the ancient cycle of reproduction, populating the oceans with these prehistoric reptiles that have survived for over one hundred million years.

The turtle glides through the water. Her rear flippers are broad rudders; her toe bones are long, and flexible enough to steer her through the ocean. With her front flippers, she paddles swiftly, moving them upward and backward, then forward and downward, flying through the ocean like a bird on wings. She makes her way to the surface every few minutes, exhaling her breath in a noisy rush above the water and breathing in the salty air, absorbing enough oxygen for her next dive below the water.

With her domed, light shell, stream-lined to maximize buoyancy and agility in the water, she is made for the sea. Her shell is olive green and brown, with darkly mottled splotches, and her eyes are wide, pensive and still. She dives deep in the water, feeding along the bottom, and slowly slopes to the surface. Her ascent is passive and graceful. She is completely unaware of the low-frequency sound of a boat motor approaching.

Her head breaks the surface as the water around her churns and the whirring smack of the propeller slices through her front flipper and crashes into her shell. She gasps the air for broken breath, but is too shocked by impact to see the foreign object speeding away in the sunny afternoon. The stillness of the water has disappeared, and in its place, the sea turtle bobs along the surface of the water. She floats, her flipper hanging limply at her side, not completely separated, but useless. The shock and pain of the accident has blinded the turtle of her earlier purpose, and she can do nothing but move slowly through the water, using the strength of only one flipper to paddle to a comfortable place.

1 comment:

  1. That damn Sam!

    Did I tell you about the time Mary and I saw a hatching in the Outer Banks? Absolutely amazing!

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