More than 3,000 dolphins have been found dead on beaches in Perú this year, and environmentalists are so far stumped as to what could be the cause, Perú 21 reports. One theory is that powerful waves caused by oil exploration ships could have resulted in internal damage for the mammals, Carlos Yaipen Llanos, science director of the marine mammal rescue group Organización Científica para Conservación de Animales Acuáticos (ORCA), told the Peruvian news source, according to Discovery News.The first hundred dolphins washed up on the shores in February, leading some to originally hypothesize they had consumed toxic fish, though testing unable to confirm this was the case.