A small island in the province of Guanacaste is gaining significant attention among marine conservation circles as the busiest point for sea turtles that massively arrive in Costa Rica during nesting season. San Jose island is part of the Guanacaste Conservation Area (Spanish initials: ACG), and from November 2012 until this past May had registered 1,933 nesting events on its sandy beaches.

Marine biologists and ACG officials have been closely monitoring sea turtle nesting behavior on San Jose island in recent years. They estimate that this small island is the busiest nesting point for sea turtles in Central America. The busiest month appears to be January, but not all arrivals result in successful nesting events. In fact, out of the 1,933 arrivals, only 791 were successful in nesting; this is due to climate factors and the presence of predators.

The arrival patterns of sea turtles on San Jose island indicates that these species alternate their nesting between Ecuador, Costa Rica and Mexico. In Guanacaste, their arrival peaks around Christmas time; their favorite spots at that time are San Jose island, Playa Cabuyal, Playa Colorada, Nancite and Playa Naranjo. Researchers tagged 250 females, out of which 34 did not lay eggs on every beach arrival. This accounts for one of the highest sea turtle fertility rates in the Pacific region of the Americas.

Researchers and ACG officials are requesting assistance from the government with regard to greater protection for places such as San Jose island. Although this is a remote area, officials are concerned about the presence of poachers in the area. The solitude of these conservation areas may also attract drug traffickers looking for secret locations for smuggling and beach drops. Other concerns include massive real estate development in the region.