(HOST) Commentator Ted Levin recently returned from Costa Rica, where he discovered a business venture based on the conservation of an dangered species and the preservation of a rural culture.

(LEVIN) "Everyone ought to see a turtle nesting," wrote the late Archie Carr, preeminent biologist and author. "It is an impressive thing to see, the pilgrimage of a sea creature back to the land its ancestors left a hundred million years ago. When the turtle strands in the surf... She blinks and peers," continued Carr, "turns her nose down and presses into the wave-washed bottom, then she looks up and all around and blinks some more. She is clearly making a decision. What her criteria are nobody knows. The turtle is wild and skittish when she first touches shore, and even the light of a match struck far up the beach may turn her back to the sea."

When Carr wrote his book, "So Excellent a Fishe: A Natural History of Sea Turtles," more than forty years ago, he was referring to six of the seven species of sea turtles, all but the olive ridley, the world's smallest and most abundant oceanic turtle. An emergence of olive ridley sea turtles stops for nothing.

An olive ridley could conveniently fit in your kitchen sink, if you had a reason to put it there. Its distinctive heart-shaped carapace (or upper shell) measures up to 27 inches. An adult weighs approximately a hundred pounds. Olive ridleys are tropical nesters that forage in warm, temperate waters. They're open ocean sea turtles - as pelagic as albatrosses. They come ashore to breed, sometimes traveling more than a thousand miles to spawn. Olive ridleys are carnivorous, feeding mostly on invertebrates: crabs, shrimp, rock lobsters (whatever they are), and jellyfish.

Until the late 1950s, they were thought to be IndoPacific turtles. Then, biologists discovered small nesting colonies in the West Atlantic, from Surinam to Brazil and along the wild coast of Africa. The olive ridley fascinates me because of is its massive synchronized nesting habit known as arribada, which is Spanish for "arrival by sea." On eight beaches in the Pacific and Indian oceans olive ridleys storm the beach like leatherbacks at Normandy.

The largest arribada in the world occurs on a half mile of pristine shoreline of Playa Ostional, Costa Rica. Driven by offshore wind, a rising tide, and phases of the moon, swarms of turtles appear between 2:00 p.m. and 7:00 a.m. on three or four nights in the of the year, sometime between late September and early October, upwards to one million of them. There are so many turtles on such a small strip of beach that one observer described the scene as having the appearance "of an old cobblestone boulevard paved with turtles."

On the first night of the arribada Ostional villagers are allowed by government proclamation to collect eggs, which are sold throughout the country as an aphrodisiac, the Mesoamerican equivalent of Viagra. In return, villagers patrol the beach throughout the remainder of the nesting season to stop poaching. It's a marriage of economics and conservation. And in Costa Rica, at least, the olive ridleys still prosper.