Fishermen lament Rio's Olympic bay of filth

The day is still dark when Edmo Rodrigues da Costa sets out in his 6-meter fishing boat, maneuvering around clumps of trash and mounds of putrid sludge in the sewage-infested waters of Rio de Janeiro's Guanabara Bay.

For 30 years, Costa has set his nets in the bay that will host Olympic sailing events in 2016, hoping to catch sea bass, Atlantic bigeyes and shrimp. But year by year, the catches have diminished.

A good day out two decades ago would bring in $200 worth of fish. Today, Costa says a successful haul fetches $50. Sometimes, the floating refuse he finds is worth more than his catch.