Great Blue Wild

A coral reef that was decimated by overfishing off the shore of Mexico's Sea of Cortez in the 1980s and later restored by the fishermen who destroyed it is spotlighted.

A shark sanctuary in Palau is spotlighted.

The island nation of Palau is spotlighted. Included: large manta rays; massive World War II shipwrecks; one of the largest reefs in the world.

Researchers observe manta rays off the coast of Raja Ampat in the Indonesian archipelago.

Indonesia's marine rainforests are under threat, and rising sea temperatures and destructive fishing practices have taken a toll. However, conservation initiatives in hundreds of protected marine zones have given hope to the giant manta rays, 300 species of coral, and six of the world's seven sea turtle species that call this ecosystem home.