The Osa Peninsula, on the South Pacific side of Costa Rica is known by National Geographic as the most biologically intense place on Earth. The waters off the Osa Peninsula are a virtual marine wonderland, housing over twenty-five species of dolphins and whales that live here year round or migrate through and also hosts four of the world’s eight species of sea turtles. 

In fact, Costa Rica enjoys one of the most biologically diverse ocean ecosystems in the world. This is mainly because the heart of a vast habitat known as the Costa Rican Thermal Convection Dome, named for its proximity to this country, lies here. Shallow warm waters lie on top of low-oxygen cold water, creating the perfect ecosystem for a vast variety of marine life. The dome off the coast of Costa Rica is the only one in the world that is constant. Such conditions provide the Costa Rican Pacific waters with a very unique scheme of biological richness. Whales, dolphins, tuna, marlin, manta rays, sea turtles, sailfish and more, congregate in this area taking advantage of this year-round thermal dome of ecologically rich waters.

All this rich biodiversity is found here on the Osa Peninsula, but yet, the area is almost entirely unprotected, except for small areas around the national parks. Commercial fishing techniques such as long lining, shrimping, gill netting and tuna fishing are wreaking havoc on this delicate and biologically diverse area and its marine inhabitants, and if urgent and drastic actions are not taken immediately, the world will lose this treasure forever.

From: MPA for OSA