Rio Olympics 2016: 33 Tonnes of Dead Fish Swarm Olympic Venue

Two waterways in Rio de Janeiro are swarmed with 33 tonnes of dead fish just 16 months before the 2016 Olympic event.

About 33 tonnes of dead fish and various trash were cleared out from the waterways by more than 50 people who started working since last week, according to The Guardian. The Guanabara Bay and the Lagoa Rodrigo de Freitas lagoon in Rio de Janeiro are the venues for the 2016 Olympic rowing and canoeing sport.

The department officials said that the people from the city's sanitation department have been working daily since last Wednesday to remove the fish and continue doing so until the waterways are cleared.

Some specialists are saying that twaite, the death of a number of fish, is due to oxygen starvation brought about by water pollution. Others believe that it is caused by the fluctuating water temperature and oxygen levels, according to the BBC.

This is not a new phenomenon for the Brazilian lagoon. For more than a decade, tonnes of dead fish wash up on the surface and banks at certain times. The smell of the lagoon has led to complaints both from residents and local rowing clubs.

Alex Moutinho, a local photographer who has lived near the lake for many years, told the Associated Press, "Every year there are these die-offs, sometimes bigger, sometimes smaller."

"It's one more Brazilian shame," he added.

This is the second case for the year 2015. Last February was the first massive twaite die-off in the Guanabara Bay, the reasons were unknown.

"There was a big effort to stop sewage and we removed everything possible," Paul Rosman, an oceanographer, told Reuters. He blames the fish's death to the carbon dioxide build up due to the increase of algae blooms.

"But reducing the sewage doesn't mean you have reduced the algae blooms. That happens because of the excess of nutrients in the water," he added.

Brazilian authorities pledged to clean up some of the waterways ahead of the 2016 Olympics but fears they might not be able to make the commitment, according to an article by Huffington Post.

In a letter by Carlos Francisco Portinho, Rio's state environment secretary to Sports Minister Aldo Rebelo, he said that it will take many more years to clean up the bay. The letter asked for more funding to de-pollute the waterways but government data show that the sewage pollution increased above acceptable limits and appears to be an indication from the state environment officials that they cannot meet their goals.