Once a near-legendary paradise, Rio de Janeiro's Guanabara Bay now suffers from unprecedented levels of pollution. Tons of household garbage, toxic liquids and sewage are dumped straight into the sea. Despite the investment in 1995 of one billion dollars in a program to fight the bay's pollution, nearly 20 years later the prognosis continues to alarm. Biologist and activist Mario Moscatelli has spent the last 15 years speaking out about the problem. Every month, camera in hand, he takes stock while flying over the area in a helicopter. Duration: 02:07