Jean-Michel Cousteau travels with his son and daughter, Fabien and Celine, and team to the high Arctic to discover why some beluga groups are thriving and others are disappearing.

There are places on this planet where it's a marvel that anything survives. In the cold Arctic waters of the far north, the sea is alive with sound. The canaries of the sea are singing. They're beluga whales, named from the Russian word for "white ones." They're an evolutionary surprise - a warm-blooded mammal in a numbingly cold sea. Resembling curious ghosts, these intelligent mammals use one of the most complex sonars of any animal. In this episode, Jean-Michel Cousteau travels with his team to the high Arctic to determine why some beluga groups are thriving and others are disappearing. There's a clear connection between human activity and the beluga's future. The beluga's world is now ground zero for climate change; what threatens them is not confined to the Arctic - it's global. What lies ahead for the beluga could become prophecy for many species everywhere, including our own.