A total of 61 episodes of fish kill have been reported in Bengaluru in six years, according to a recent study that sheds light on the concerning trend of fish kill incidents in Bengaluru’s lakes from 2017 to 2023, highlighting insufficient efforts by authorities to address the root causes of the issue.
The study, conducted by Raghavendra B. Pachhapur, senior lead projects of ActionAid Association, titled Fishkill in Lakes of Bengaluru 2024, says despite the presence of sewage treatment plants (STPs) in four lakes, including Bhattarahalli, Munnekollala, Chelekere, and Iblur, fish kill incidents were still reported, indicating a failure to utilise the STPs effectively despite investments in their operation and maintenance.
The report identified sewage flow into the lakes as a primary reason for fish kill incidents throughout the six years, with only January and October being exceptions. Most of the affected lakes are situated around 110 villages, with only two exceptions, Sankey and Madiwala tanks.
Kothnur lake reported the highest number of fish kill episodes, with six incidents, followed by Haralur with five, and Madiwala, Bhattarahalli, and Kundalhalli with three episodes each. In 2023 alone, 20 fish kill episodes were reported.
According to the Karnataka State Pollution Control Board (KSPCB) water quality analysis report, three lakes (Bhattarahalli, Doddakallasandra, and Sankey Tank) were classified under Class D, while nine lakes were classified as Class E, indicating conditions not conducive for wildlife/fisheries. High levels of bio-chemical oxygen, chemical oxygen, and faecal coliform were found to exceed permissible limits.
The report emphasised the need for measures such as harnessing rainwater from surrounding areas, monitoring water quality, clearing sludge, solid waste, and plastics from lake inlets, and ensuring sewage diversion channels are free from blockages before the monsoon.
In conclusion, the report highlighted the importance of wetlands for lake conservation, emphasising their role in supporting biodiversity, regulating local climate, and acting as carbon sinks. It called for urgent action to address the root causes of fish kill incidents and ensure the long-term health of Bengaluru’s lakes.
Kothnur lake reported the highest number of fish kill episodes, with six incidents, followed by Haralur with five, and Madiwala, Bhattarahalli, and Kundalhalli with three episodes each. In 2023 alone, 20 fish kill episodes were reported.
