More than 400 dolphins washed up on beaches in Peru last month, leaving scientists and marine biologists baffled.
Peruvian Sea Institute (IMARPE) official Jaime de la Cruz, in Chiclayo, said the bodies have been found across the northern departments of Piura and Lambayeque, and that samples of the animals' remains were sent to Lima for autopsies.
Carlos Yaipen, a marine veterinarian at the NGO Sea Animal Conservation Scientific Group (ORCA), told the Daily Telegraph that a couple of possible causes have been suggested.
Local reports have speculated that toxic algae is responsible, but Mr Yaipen highlighted that humans would also be affected as they ate animals from the sea.
He thought perhaps the dolphins could have had a tragic reaction to acoustic impact from oil companies doing exploratory drilling in the area.
Back in 2012, authorities failed to establish the cause of the death of 870 dolphins in the same region after tests came back inconclusive.
Officials are now performing autopsies on the latest dolphins found dead, but according to the Independent, determining their cause of death is "complicated" in Peru because government laboratories only have three or four of the approximately 100 chemical reagents in the world that can determine the cause of death.
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