Thursday, February 9, 2012

Costa Rica - Olive Ridley Turtles

An '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 synchronized nesting in mass emergence and by producing large numbers of offspring, these turtles insure their survival even after predations occurs. The secrete is to produce more than the predators can consume.



Some days or weeks before the mass nesting, the sea turtles congregate close offshore. After some days, prompted by some unknown signal, the 'arribada' will begin. A steady stream of turtles will come out onto the beach continuously for the next 3 to 5 days, like an invading army.





Ostional of Costa Rica is one of the only four beaches on the Pacific Ocean that hosts these spectacular 'arribadas'. For 10 months a year, usually around the third quarter of the moon (lunar month), the Olive Ridley Turtles swim by the hundreds of thousands to a single mile of 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.




As the capacity of the one-mile beach is insufficient for the large numbers of turtles, 70% to 80% of previously laid nests are crushed or dug up during the subsequent nesting. Bacteria will grow on the broken eggs and contaminate the later nests.

It is for this reason that the Costa Rican Government has legalized controlled egg harvesting to preserve the turtles. Villagers are allowed to harvest eggs laid within the first 36 hours of the 'arribada'.





"Legalized poaching to preserve the species"




In return, the villagers protect the turtle from dogs and vultures, clean debris from the beach and patrol day and night for poachers.





At time when the baby turtles struggle out of the sand and race to the ocean, women and children from Ostional will be at the beach protecting them from dogs and vultures.




Legalized poaching helps stabilized the population of the olive ridley turtles, the most abundant of the world's sea turtles.



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