Peggy Knapp. Peggy Knapp was >> in A Sea Change for Superior: The Warming of the World's Largest Lake as 'Narrator (voice)'.John Thain. John Thain was >> in A Sea Change for Superior: The Warming of the World's Largest Lake as 'Director'John Shepard. John Shepard was >> in A Sea Change for Superior: The Warming of the World's Largest Lake as 'Writer, Producer'Tracy Fredin. Tracy Fredin was >> in A Sea Change for Superior: The Warming of the World's Largest Lake as 'Executive Producer'Nina Fredrickson. Nina Fredrickson was >> in A Sea Change for Superior: The Warming of the World's Largest Lake as 'Production Manager'