NBC NATIONAL NEWS — Scientists are at a loss to explain a historic number of dead dolphins in northern Peru.

More than 800 dolphins have washed up along the coast since late March.

The dolphins have had broken bones in their ears and some of their organs have collapsed.

One scientist says the animals showed signs of being affected by seismic activity stemming from oil exploration in the area.

However, scientists have not reached any concrete conclusions in their investigation.

Peru has reportedly invited scientists from the U.S. National Oceanic and Atmospheric administration to help with the investigation.