Hunting and egg harvesting nearly brought green sea turtles to the brink.

Jellies live in virtually every part of the ocean and come in a dizzying array of shapes, sizes, and colors. Some, like the aquarium's box jellies, are no bigger than a thimble.

Displaying a great white has long been a dream of aquariums around the world. But previous efforts to care for the sharks have largely ended in failure.

One of the most remarkable pieces of equipment designed by Widder is the Eye-in-the-Sea, a unique, unobtrusive camera that sits on the sea bottom and records the never-before-seen behavior of marine animals.

(Airs Sunday, June 28) Underwater cameraman Bob Cranston explores the remarkable world of marine creatures called cephalopods -- squids, cuttlefish, octopi, and nautili.

There is one less mystery in the deep sea: for the first time, two Japanese researchers have finally photographed a live giant squid in its ocean home.

Dolphins use sound to detect the size, shape, and speed of objects hundreds of yards away. The dolphin's natural sonar, called echolocation, is incredibly precise