text: Dead fish have continued to wash up on the banks of a Rio de Janeiro lake that is scheduled to hold Olympic rowing competitions during the 2016 games. Fish die-offs are a frequent occurrence in Rio's waterways, which are choked with raw sewage and rubbish. The latest incident, affecting thousands of small silvery fish called twaite shad, began several days ago at the Rodrigo de Freitas lake, where the Olympic canoeing and rowing events are to be held. The Rodrigo de Freitas lagoon will hold the Brazil 2016 Olympics rowing and canoe competitions . Currently, the lake is littered with thousands of dead fish due to the raw sewage and rubbish within it . With neighbors complaining about the stench, employees of the city's waste management company have been working to clear away the dead fish. 'Every year there are these die-offs, sometimes bigger, sometimes smaller,' said photographer Alex Moutinho, who has lived near the lake for over three decades. 'It's one more Brazilian shame.' In a statement, the city's environmental secretariat said the latest incident was the result of recent rains and high sea levels, which caused the lake's water temperature to plummet. The statement stressed that twaite shad are sensitive to variations in temperature, adding that oxygen levels in the lake were normal. Officials say the recent problems are the result of rain, which caused the lake's temperature to plummet . The city's waste management company have been brought in to clear the lake of the dead fish . Vultures feed on the dead fish on the shore of the Rodrigo de Freitas lagoon in Rio de Janeiro on Monday . Previous fish die-offs in the lake have been blamed on pollution-related drops in oxygen levels. The cause of February die-off of twaite shad in the Guanabara Bay, where the Olympic sailing events are to be held, were not known. Rio's water quality has become a contentious topic ahead of the 2016 Olympics. Authorities had pledged to clean up some of the waterways including the Guanabara Bay ahead of the games but now admit those promises won't be met, sparking sailors to voice worries about possible health and safety threats posed by competing in the sewage and garbage-filled waters. Residents concerned about the water quality of a canal in the Rio neighborhood of Recreio staged a protest on Sunday. Hundreds of demonstrators linked arms along the Canal das Taxas, which is filled with raw sewage from nearby condominiums. The canal flows into a lagoon where the Olympic Park is being built.
target: 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 .