RIO DE JANEIRO – At least 37 tons of dead fish have been removed over the past week from this Brazilian metropolis’ Rodrigo de Freitas lagoon, one of the venues for the 2016 Rio Olympics, officials said Thursday.
Employees of the Comlurb municipal waste management company were continuing to use nets to remove the silvery fish, called twaite shad, many thousands of which were found floating on the surface or washed up on the shores of the lake.
Despite the strong smell associated with the fish die-off, several canoeists got in a training session Thursday on the lagoon.
The municipal Environment Secretariat blamed the phenomenon on a rapid drop in the lake’s temperature due to strong rains and a rise in the level of the ocean, which is connected to the lake by a canal.
Twaite shad are extremely sensitive to fluctuations in temperature.
The lake’s ecosystem will remain out of balance in the coming days because the decomposition of the dead fish affects the level of dissolved oxygen, the secretariat said.
The latest measurements showed that the lagoon’s oxygen levels are normal and its temperature is stable at 28 C (82 F).
Rodrigo de Freitas, a popular recreational and tourist spot in Rio de Janeiro, is located between Ipanema beach and the foot of Mount Corcovado, where the Christ the Redeemer statue stands.
The lagoon, which is home to several local rowing clubs, will host the rowing and canoeing competitions at next year’s Summer Games.