Philippineindex.com

The country’s northern beaches were declared off-limits earlier this week as scientists scrambled to pin down what was causing the massive death toll, with non-government organizations blaming oil exploration work.

But Peru’s deputy environment minister, Gabriel Quijandria, disputed this and said that warming waters, which disturbs species’ food supplies, was a possible cause.

He added that although tests conducted on 877 dolphins found dead on the coast had not been completed, contamination from heavy metals or the presence of bacterial infections was not responsible.

It is probable that the phenomenon “will extend to other coastal areas,” Quijandria said, noting that there could be a resulting increase in the numbers of birds and other sea life killed.

The South American nation’s health ministry declared an alert over the weekend, urging the public to stay away from the beaches around the capital Lima and on the northern coast until the animals’ cause of death is known.

One non-government conservation organization, known as ORCA, has blamed the dolphin deaths on oil exploration activities in the area, which it claims produces noises that are having an acoustic impact on the mammals.

A representative from the group, Carlos Yaipen, said also on Wednesday that it had tested 30 dead specimens and found broken ears and damaged organs consistent with the victims suffering “the bends,” also known as decompression sickness.

Weather expert Abraham Levy told Agence France-Presse on Tuesday that the warming of the Pacific waters due to El Niño could be to blame.