Changing Seas

Each year, thousands of tourists interact with the tame southern stingrays that congregate in the shallow waters of Grand Cayman's North Sound.

The unique oceanographic conditions of the eastern tropical Pacific make the area one of the best spots in the world for big game anglers to hook billfish.

Most people are familiar with the pretty tropical fish found in aquariums, but few realize that some of these animals are capable of changing sex.

Shows how recent DNA research has cast doubt on the theory that sponges were the first animals to branch off the "Animal Tree of Life, " a kind of family tree for all living and extinct animals on earth.

Every winter, hundreds of manatees aggregate at Crystal River, Florida.

This episode takes viewers into an area of the remote Pacific, the islands of Maug.