Officials blame it on `dirty water' flowing into the tank
Bangalore: Several dead fish were floating at the Lalbagh tank on Wednesday. Joggers were seen covering their noses unable to bear the stench.
A senior official at the Lalbagh Botanical Garden told The Hindu that this was not an unusual phenomenon. "This happens after the first few rains in summer. There are two inlets in the tank connected to storm water drains. After the rain, the water brings with it waste from the storm water drain. This results in an increase in the carbon levels and decrease in the oxygen levels in the water because of which fish near the inlet die."
The official said that experts from the Department of Fisheries had been invited to look into the issue. "The experts have studied the case and even submitted a report. They have concluded that the fish kill is because of the decrease in oxygen levels in the water," he added.
S. Venkatesh Shekhar, Regional Officer, Karnataka State Pollution Control Board, said that the board regularly monitored the tank. "We collect samples from the tank once a month and analyse them. The fish kill is not new. It is because of the entry of `dirty water' from the inlets." Mr. Shekhar said the officials of Lalbagh could not block the inlet as it would cause flooding in other areas. "However, the board had submitted a show-cause notice to Lalbagh, even though this is a common phenomenon that is noticed after the first few rains," he said.
The Lalbagh officials have now covered the two inlets with mesh so that the entry of waste, including plastic and bottles, is restricted. "We are continuously taking steps to ensure that the tank is clean. However, such incidents cannot be avoided," the Lalbagh official added.