The Rodrigo de Freitas lagoon will hold the Monday Olympic rowing races . Currently , the lake is filled with thousands of dead twaite shad fish . Rio 's waterways are choked with raw sewage and rubbish , and concerns have been raised over health and safety ahead of the Olympics . Officials say the deaths are due to a plummet in the water temperature .
The Rodrigo de Freitas lagoon will hold the 2016 Olympic rowing races . Currently , the lake is filled with thousands of dead twaite shad fish . Rio 's waterways are choked with raw sewage and rubbish , and concerns have been raised over health and safety ahead of the Olympics . Officials say the deaths are due to a plummet in the water temperature .