A sofa floats in the polluted waters of Jacarepagua Lagoon, during a press tour in Rio de Janeiro, March 9, 2015. A press tour was organised by biologist Mario Moscatelli, to call attention to pollution on the waters of the lagoons which surround the Rio 2016 Olympic Park. (Photo by Ricardo Moraes/Reuters)

A piece of a toy doll is seen on Fundao beach in the Guanabara Bay in Rio de Janeiro, July 30, 2015. (Photo by Sergio Moraes/Reuters)

A toy is seen at Pombeba island in the Guanabara Bay in Rio de Janeiro March 12, 2014. (Photo by Sergio Moraes/Reuters)

Dead fish lied next to a soccer ball on the banks of the Guanabara Bay in Rio de Janeiro February 24, 2015. (Photo by Ricardo Moraes/Reuters)

Rubbish are seen on the banks of Rodrigo de Freitas Lagoon in Rio de Janeiro August 13, 2014. (Photo by Ricardo Moraes/Reuters)

Rubbish covers the banks of Cunha channel, which flows into Guanabara Bay, during a press tour in Rio de Janeiro, March 10, 2015. (Photo by Ricardo Moraes/Reuters)

Rubbish is pictured on the banks of Cunha channel, which flows into Guanabara Bay, during a press tour in Rio de Janeiro, March 10, 2015. (Photo by Ricardo Moraes/Reuters)

Men ride a boat on Jacarepagua Lagoon, next to a barrier to collect rubbish, during a press tour in Rio de Janeiro, March 9, 2015. (Photo by Ricardo Moraes/Reuters)

Rubbish covers the banks of Cunha channel, which flows into Guanabara Bay, during a press tour in Rio de Janeiro, March 10, 2015. (Photo by Ricardo Moraes/Reuters)

A bird eats a fish surrounded by dead fish on the banks of the Guanabara Bay in Rio de Janeiro February 24, 2015. (Photo by Ricardo Moraes/Reuters)

A toy doll is seen on Fundao beach in the Guanabara Bay in Rio de Janeiro March 13, 2014. (Photo by Sergio Moraes/Reuters)

A toy car rests on the banks of Jacarepagua Lagoon, during a press tour in Rio de Janeiro, March 9, 2015. (Photo by Ricardo Moraes/Reuters)

A view of Jacarepagua Lagoon, during a press tour in Rio de Janeiro, March 9, 2015. (Photo by Ricardo Moraes/Reuters)

A man walks, with the Sugar Loaf Mountain in the background, near garbage on Botafogo beach in the Guanabara Bay in Rio de Janeiro March 12, 2014. (Photo by Sergio Moraes/Reuters)

Garbage is seen near a fishing boat on Fundao beach in the Guanabara Bay in Rio de Janeiro March 13, 2014. (Photo by Sergio Moraes/Reuters)

Dead fish are pictured on the banks of the Guanabara Bay in Rio de Janeiro February 24, 2015. (Photo by Ricardo Moraes/Reuters)

A bird flies next to garbage in the Guanabara Bay in Rio de Janeiro March 12, 2014. (Photo by Sergio Moraes/Reuters)

A plastic bottle and a tire are seen near a fishing boat on Fundao beach in the Guanabara Bay in Rio de Janeiro March 13, 2014. (Photo by Sergio Moraes/Reuters)

A pipe is seen near a fishing boat on Fundao beach in the Guanabara Bay in Rio de Janeiro March 13, 2014. (Photo by Sergio Moraes/Reuters)