The Magical Arribadas of Playa Ostional

by Alison Vieira

One of the most profound and beautiful biological encounters any wildlife enthusiast can experience locally is an “arribada”. An arribada is a Spanish term used for “arrival” and in the Nosara area, the word is synonymous with the mass synchronized nesting of Olive Ridley sea turtles on the black volcanic sands of Playa Ostinal. Just a few kilometres north of Playa Guiones, within the World Wildlife Fund’s recognized conservation site of the Ostinal Wildlife Refuge, this year round phenomenon takes place to the delight of locals and tourists alike.

Named for their olive color with their heart-shaped shell known as the carapace, Olive Ridley’s are one of the smallest of the sea turtles with adults reaching 2 to 2½ feet in length and weighing 80 to 110 pounds. Arribadas occur at least once a month, with peak numbers of these ladies of the sea emerging during the Green Season months of July to December.

Linked with the wind, tide and lunar cycles; just before a new moon, female turtles will gather off shore in groupings of hundreds and sometimes thousands in an oceanic tribal gathering of wait. When the elements align, collectively they will make their spectacular arrival to land, literally arriving within the waves. Once ashore, they slowly haul their heavy bodies from the surf to begin maneuvering up the beachscape as they waddle along making their unique patterned imprints in the sand. When each finds her ideal spot to create a pocket, using her hind flippers and in an almost in a trance-like state, she will deposit between 80 – 110 white soft-shelled eggs. Afterwards, she will cover up her shallow nest, leaving the offspring behind as she returns back to the ocean. The hatchlings will surface at night within 45 to 54 days of nesting depending on the atmospheric incubation temperatures. As soon as they emerge from the nest, these little ones will crawl as fast as possible to the sea, which is another awe-inspiring sight of Mother Nature to behold.

At Wanderlust Realty, we advocate visiting the Ostional arribada nesting site with sanctioned guides, through authorized access points, which honors their process respectfully.