On Cuba's far-flung Guanahacabibes peninsula, park guard Roberto Varela watches as a green sea turtle lumbers ashore and a ritual as old as the dinosaurs unfolds.
"To see them lay their eggs and to know their nests will be protected, you get the sense you are making a difference," said Varela, who helps oversee turtle research in a national park that spans much of the peninsula.
So far, efforts by Varela and fellow researchers at the park and University of Havana have been a success. Turtle nesting here, once threatened by poaching, has stabilized and increased in some cases, published studies show, even as it has fallen off elsewhere in the tropics.