for National Geographic News
As dawn breaks on Playa Grande, the light reveals shallow sand pits where leatherback sea turtles laid their eggs the night before.
This Costa Rican beach, a 2-mile-long (3.2-kilometer-long) stretch of sand popular with surfers, is guarded around the clock by a small army of biologists and volunteers from the Leatherback Trust, a nonprofit group working to save the world's largest sea turtles from extinction.
That means ensuring that every turtle nest on the beach—which is open to the public for recreation—is kept undisturbed.
"This is the most important nesting beach for leatherbacks in the eastern Pacific," said Gabriela Blanco, who heads the trust's monitoring station.
"If we don't protect the beach, this population is going to disappear."
As adults, leatherback turtles can grow as long as six-and-a-half feet (two meters) and weigh up to 2,000 pounds (900 kilograms).
Ranging further than any other reptile, they are found in the Atlantic, Pacific, and Indian Oceans as well as in the Mediterranean Sea.
Recently a leatherback turtle migrated 12,774 miles (20,558 kilometers) across the Pacific Ocean—the longest recorded migration of any sea vertebrate.
But the animals are highly endangered due to human threats such as poaching, beach development, and harmful fishing practices.
For instance, scientists estimate that less than 5,000 nesting leatherbacks exist in the Pacific Ocean today, a 95 percent drop from 1980.
(Related: "Leatherback Turtles Near Extinction, Experts Say" [February 24, 2003].)
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