Expert: Dolphin deaths in Peru still a mystery

Associated Press
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In this April 6, 2012 photo, officials stand next to dolphin carcasses on the shore of Pimentel Beach in Chiclayo, Peru. Scientists and Peruvian officials are investigating a mass die-off of hundreds of dolphins along the South American country's coast. (AP Photo/Nestor Salvatierra)

LIMA, Peru (AP) —