George Duffield photos

Cocos Island National Park is probably best known for its teeming populations of sharks, rays, and spectacular scalloped hammerhead sharks, sometimes seen numbering in the hundreds. White tip reef sharks are also abundant, as are marbled and eagle rays and endless schools of jacks  that swarm the island. Silver tip sharks, Galapagos sharks, black tip sharks, and silky sharks are also sighted regularly. The high point of any diving expedition--whale sharks--are also occasionally observed. More than 270 species of marine fishes are known to swim the reefs and nearshore waters of the island. Marine mammals residing in these aqua-blue waters include bottlenose dolphins and spotted and spinner dolphins. Humpback, sperm and other whales and dolphins migrate through these waters.

Costa Rica's Cocos Island National Park is located in the eastern Pacific Ocean 550 km (340 miles) south of Puntarenas, Costa Rica, Rica and 630 km (394 mi) northeast of the Galapagos Islands of Ecuador. It was established as a National Park  in 1978, and in 1987 a 15 km radius of the marine environment surrounding island was added for protection. The marine area was increased to 22.2 km in 2001. Regulations prohibit commercial and recreational fishing. In 1997, the Park was designated a United Nations World Heritage Site.

Four species of sea turtles have been recorded inside the Park's marine boundaries, though little else is known about the turtles of Cocos, including whether or not any species nest there, though presumably most of the turtles do not (as there is limited nesting habitat). Adult and juvenile green turtles are commonly seen foraging in the marine waters of Cocos Island, as are hawksbill turtles. The migration route of critically endangered Pacific leatherback turtles leaving the most important nesting rookery in the East Pacific, located on Costa Rica's mainland, migrate through the area. Presumably olive ridley turtles also migrate through the Park.

Clearly, Cocos Island is an important foraging area for both adult and green sea turtles, but we do not know if these turtles are part of populations emanating from the Galapagos Islands, the mainland of Central America or possibly even the west Pacific. Very little is known about juvenile green turtles or their foraging habitat, and even less is known about hawksbills in the East Pacific. These are some of the answers we hope to answer with our research and monitoring program which will help elucidate the migration routes to provide necessary policy recommendations to protect and restore the sea turtles of the East Pacific.

For information about how you can join a Cocos Island diving expedition and help support this important research and monitoring work, click here.