A pair of voyages with noted ocean explorer Jean-Michel Cousteau reveals the surprising interdependence between marine mammals and humans, as well as how climate change, pollution and dwindling habitat affect life both on land and in the sea. In "Sea Ghosts," Cousteau journeys to the Arctic to document conservation efforts aimed at protecting white beluga whales, and in "Call of the Killer Whale," he sails the globe to study lethal orcas.