Louie Psihoyos's 2009 covert exposé of a Japanese dolphin hunt. Won Best Documentary Oscar.
From Wikipedia
The Cove is a 2009 American documentary film directed by Louie Psihoyos that analyzes and questions dolphin hunting practices in Japan. The film is a call to action to halt mass dolphin kills and captures and change Japanese fishing practices. It also seeks to inform and educate the public about the dangers of keeping cetaceans in captivity and the increasing hazard of mercury poisoning from consuming dolphin meat.