National Geographic : 1994 Feb
URTLES POURED OUT of the surf in wave after wave through the darkness. Heaving, huffing, Gasping turtles plowed the coarse black sand with their noses, laboring onto shore. On this rain-soaked October night possibly 30,000 olive ridley sea turtles were converging on a half mile of Pacific beach at Ostional, Costa Rica, in a biological extrava ganza called la arribada-thearrival. Following instincts that scientists have not begun to understand, the turtles had gathered offshore for mating, and now hordes of females were swimming to this particular beach to lay eggs. By 2 a.m. the beach looked like a cobblestone street where the cobble stones had come to life. And still more turtles were coming. All night they advanced and retreated. They collided and piled up in jams. They filled the air with the soft sound of flip pers hollowing nests in the sand and a rhyth mic thump thump thump as turtles that had finished laying rocked their 80-pound bodies to pack sand over their eggs. The turtles wheezed and shed tears, bathing their eyes from the flying grit they kicked up. It was dawn when stragglers plowed the last trails back to sea. Thousands of other females still laden with eggs were swimming beyond the breakers, waiting for next evening's high tide when they would begin the assault anew. All sea turtles come to shore to lay eggs, but for most it is a relatively solitary affair. Only the olive ridley and its Atlantic cousin, Kemp's ridley, stage arribadas. Watching those legions of olive ridleys break from the night surf, it was hard to remember that sea turtles are in serious trouble. All eight species are endangered or threat ened. They are killed for meat and leather; Previous GEOGRAPHIC contributions by ANNE and JACK RUDLOE include articles on the Atchafalaya swamp in September 1979 and horseshoe crabs in April 1981. BILL CURTSINGER'S photographs appear frequently in the magazine, most recently in "Bikini's Nuclear Graveyard," in June 1992.