There are places on this planet where it is a marvel that anything survives. But in the cold Arctic waters of the far north, the sea is alive with sound. The canaries of the sea are singing. They are beluga whales, named from the Russian word for "white ones." Belugaas are 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. Their world is now ground zero for climate change.
