Peru's mysterious dolphin and pelican deaths - in pictures

Pelicans are seen in the waters along Cerro Azul beach in Canete, Lima Photograph: Mariana Bazo/Reuters

Bathers rest near dead seabirds on the beach at Cerro Azul in Canete, Lima Photograph: Mariana Bazo/Reuters

An inca tern and a pelican are seen with gulls in the waters off Cerro Azul beach in Canete, Lima Photograph: Mariana Bazo/Reuters

A dog looks at a dead pelican lying along Cerro Azul beach in Canete, Lima Photograph: Mariana Bazo/REUTERS

Health ministry workers stand by carcasses of pelicans on the shore of Pimentel beach in Chiclayo, Peru Photograph: Nestor Salvatierra/AP

A dead guanay cormorant bird lies on Cerro Azul beach in Canete, Lima Photograph: Mariana Bazo/Reuters

A health ministry worker holds up the carcass of a pelican on the shore of Pimentel beach in Chiclayo, Peru Photograph: AP

A dying pelican crawls away from the surf to die on the beach of Paita, in Tumbes, near the border of Ecuador Photograph: Silvia Oshiro/AFP/Getty Images

Dead cormorants are found on the beach of Paita Photograph: Silvia Oshiro/AFP/Getty Images

Dead pelicans are seen at Reventazon beach, close to the Illescas peninsula in Piura Photograph: Heinze Plenge/Reuters

Dead pelicans are displayed by conservationists at Reventazon beach Photograph: Heinze Plenge/Reuters

Wildlife engineer Guillermo Boigorria and regional prosecutor Lev Castro inspect washed ashore carcasses of pelicans and other sea bird species at the beach of Port Eten, 800kms north of Lima Photograph: Violeta Ayasta/AFP/Getty Images

Regional prosecutor Lev Castro (L) walks next to Wildlife engineer Guillermo Boigorria (R) who carries an infected cormorant for analysis after it washed ashore at the beach of Port Eten Photograph: Violeta Ayasta/AFP/Getty Images

A dead dolphin in a beach of Caleta San Jose, Peru. As many as 877 dolphins washed up on the coast of northern Peru, the country's deputy environment minister said Photograph: EFE/EPA

Dolphin carcasses are seen after being displayed by conservationists and environmental police officers at San Jose beach, 40kms north of Chiclayo Photograph: Heinze Plenge/REUTERS

A dead dolphin on a beach of Caleta San Jose, Peru Photograph: EFE/EPA

Dolphin carcasses are displayed by conservationists and environmental police officers at San Jose beach, 40kms north of Chiclayo Photograph: Heinze Plenge/Reuters