This refuge was declared to protect a major nesting beach for Pacific Ridley Sea Turtles, as well as the waters offshore from the beach.

Several times a year, female turtles come ashore in such numbers that the sandy beach begins to resemble a stretch of rocky coastline. These mass nesting episodes are locally referred to as "arribadas," or arrivals. One of these events can last from two to eight days with most nesting taking place at night.

Locals will tell you that the arribadas begin three or four nights after the full moon, and this is typically the case in months when relatively small numbers of individuals nest, but during the peak nesting season from July through November when more than 100,000 nests may be made during a single arribada, any correlation with phases of the moon or the tides breaks down completely. What triggers the mass nestings is still a mystery.

Scientists suggest that this species produces a superabundance of nests as a strategy for survival against predators, since with so many eggs laid in just a few nights (a million or more during a large arribada) it is unlikely that the local natural predators could possibly consume them all. Likewise, when the surviving eggs hatch and the young turtles make their scramble down the beach to the ocean, if thousands of them are doing this at more or less the same time, then some percentage of them ought to escape the variety of hungry predators that range from crabs to coyotes.

To get there: Vehicular access to Ostional is somewhat challenging, and a four-wheel-drive vehicle with good clearance is definitely recommended, especially if going in the wet season when the bulk of the sea turtle nesting occurs. The refuge can be reached from either the town of Santa Cruz or Nicoya (both situated on the main highway that runs down the middle of the Nicoya Peninsula), and following a series of gravel and dirt roads to the coast (at Playa Junquillal if coming from Santa Cruz, or Playa Nosara if coming from Nicoya) and continuing south or north, respectively, until arriving at Ostional. Although more direct, the route via Nicoya-Nosara involves fording a river that can be impassable at times in the rainy season.

To improve your chances of seeing turtles, you can try contacting the village of Ostional to find out the current status of nesting. To do so, you'll need to speak some Spanish since the phone (682-0267) is the local public phone in the village.

Fishing: To the south of Ostional Beach there are a number of charter operations between Nosara and Carrillo that can take you fishing for Sailfish, Marlin, Tuna, Mackerel, Wahoo, Bonito, Amberjack, Roosterfish, Snapper, and other game species found along this section of the Pacific coast.

Climate: The afternoon showers that characterize the months from May through November can make getting to the Ostional National Wildlife Refuge a bit difficult during the peak nesting season for Pacific Ridley Sea Turtles, however, this beach is still far more accessible than the only other beach in the country where this same phenomenon occurs, Nancite Beach in Santa Rosa National Park. Daytime temperatures are hot throughout the year, evenings are comfortable.

History: The creation of the Ostional National Wildlife Refuge is a wonderful example of the "if you can't beat 'em, join 'em" philosophy in conservation. For many years, the wholesale ransacking of turtle nests for eggs was a seasonal activity indulged in by people from all over the region, and from even as far away as San José. The widespread belief that consumption of turtle eggs produces aphrodisiacal effects has led to their popular demand as bocas (snacks served as appetizers in local cantinas).

Hampered by insufficient funding to adequately patrol the beach at Ostional, while at the same time needing the support of the local villagers, the wildlife authorities proposed a new scheme with the declaration of the refuge. The proposal was that Ostional residents, and only Ostional residents, would be granted permission to harvest a limited number of eggs during the first two nights of each nesting period and sell them only to bars with licenses to serve turtle eggs. The idea was to get the local populace to function as a police force to safeguard their own interests and protect the later nests at the same time since these have a better chance of success (early nests are often inadvertently excavated by turtles arriving later on during an arribada).

This novel policy has generated much debate, but it seems to be working effectively.