Arribada is a unique nesting phenomenon common to only two species of marine turtles, the Olive Ridley Sea Turtle and the Kemp’s Ridley Sea Turtle.
This extraordinary phenomenon of mass nesting are seen in the coastlines of India, Sri Lanka, Costa Rica and Â in some part of Central America and Mexico.
In Costa Rica, one of host of these spectacular arribadas, for 10 months the year, usually around the third quarter of the moon, the Olive Ridley Turtles swim by the hundreds of thousands to the beach of Ostional in an ancient reproduction rite.
The largest ‘arribada’ was recorded in 1995 November when a calculated 500,000 olive ridleys came ashore. With an average of 100 eggs per turtles, that was 50 million eggs that were deposited.
But when the turtles come to lay eggs, they attract some hungry vultures eying for their eggs. For the record, 70% to 80% of previously laid nests are crushed or dug up during the subsequent nesting.
Protecting the unhatched eggs, the Costa Rican government legalizes the harvesting of eggs to stabilize population of the turtle. Villagers are allowed to harvest eggs within the first 36 hours of the arribada. But In return, the villagers will protect the turtles from dogs and vultures, clean debris from the beach and patrol day and night for poachers.