This time of year is nesting season for leatherback sea turtles in the Atlantic. After mating at sea, these big mamas—leatherbacks are the largest of all turtles—haul themselves up onto beaches in the same region where they were born. The turtles dig out nests in the sand and lay a clutch of about 80 fertilized eggs the size of billiard balls. They"ll repeat this ritual a few more times before returning to their migratory lives in the open ocean. About 65 days later, turtle hatchlings will start to poke up through the sand and make a dash toward the safety of the sea. But the odds are against them: Only 1 percent of the hatchlings will live to reach sexual maturity, at around 16 years old.