Ostional Wildlife Refuge, Wildlife refuge in Cuajiniquil, Costa Rica

Ostional Wildlife Refuge is a protected coastal area in Cuajiniquil featuring beaches, mangrove wetlands, and forest vegetation that shelter diverse marine life and migratory birds. The landscape stretches along the Pacific shore with distinct zones that shift from sandy beaches to swampy vegetation to dense forest growth inland.

The refuge was established in 1983 to protect critical nesting grounds for Olive Ridley sea turtles and ensure their survival. Since its creation by the Área de Conservación Tempisque, it has remained essential to maintaining healthy populations of these animals.

Since 1987, Ostional residents have legally harvested eggs under a community plan: about 36 hours after an arribada begins, they collect eggs from the first nests, which would otherwise be destroyed by later turtles, and sell them; 1% of the proceeds goes to the village. The Ostional Integral Development Association coordinates this work and volunteer programs.

Access is by road, but the last kilometres are unpaved; Ostional lies about 360 km from San José and can be reached by private vehicle or public transport. Arribadas last three to four days each month, sometimes up to eight, with turtles coming ashore day and night. Egg collection by villagers takes place about 36 hours after an arribada begins.

Arribadas at Ostional can last three to four days, occasionally eight, and have brought as many as 170,000 olive ridley turtles ashore at once, day and night. Because the turtles dig over each other's nests, about 70% of the eggs are lost; since a 1984 arrangement, villagers collect eggs about 36 hours after an arribada begins, keeping 1% for themselves. The World Wildlife Fund calls the refuge one of the two most important olive ridley nesting sites in the world.