Over 900 dead dolphins washed up on he northern beaches of Peru

Over 900 dolphins dead washed up along a 137-mile stretch of beach from Punta Aguja to Lambayeque, on the northern shores of Peru over the weekend. Marine biologist Sue Rocca of the Whale and Dolphin Conservation Society, sat down on "CNN" to explain the possibilities of what may have happened. Two weeks ago on a 90 mile, stretch in the same area conservationist counted 615 dead dolphins that had washed up on shore. This brings the total to 3900 dead dolphins for the year around the world. No reports have been issued of the causes of the these deaths, but lots of speculation. What is happening in the seas, that is killing these beautiful, mystical creatures? How long before the mystery is solved, or the truth is told?