877 dolphins wash up dead in Peru. Why?

Dolphin carcasses are displayed by conservationists and environmental police officers at San Jose beach, 40kms north of Chiclayo, Peru, on April 6, 2012. The cause of death of over 800 dolphins in the last four months on the shores of Piura and Lambayeque are still being researched, Gabriel Quijandria, Deputy Environment Minister said on April 20, 2012. More about the ongoing investigation into the possible cause of these mass die-offs: CBS News, MSNBC, AFP, DPA, CNN, (REUTERS/Heinze Plenge)