Harbor porpoise disappeared from San Francisco Bay in the 1960's and 70's and in recent years have returned heartily. Biologist Bill Keener from the Golden Gate Cetacean Society talks about their return and filmmakers Jim Sugar and Jessica Sison talk about the film The Return of the Harbor Porpoise to San Francisco Bay, a award winning film that documents the history and good news story of the return of the porpoises to the once periled waters of the bay.