Indian Institute of Science’s Energy and Wetland Research Group has started a detailed biological survey of 12 city lakes to assess the impact of urbanisation on wetlands in Bengaluru.

The lakes — Ullal, Mallathahalli, Kommagatta, Ramasandra, Jakkur, Rachenahally, Sampigehalli, Venkateshapura, Somapura, Konasandra, Thalagattapura and Kothnur — are currently being developed by the Bangalore Development Authority (BDA) and these projects will now be monitored by IISc researchers who will study the changing biological diversity in and around the lakes.

Dr T.V. Ramachandra of the Centre for Ecological Sciences, IISc, told this newspaper that the study aims to detail the changes that have occurred in the eco-systems around the lakes and the adaptation by species dependent on the water bodies.

“The wetlands of Bengaluru have always been under tremendous pressure due to urbanisation. The impact over the past four decades is clearly discernible,” Dr Ramachandra said.

“The researchers will study the micro-organisms that thrive in the lakes and the various food chains in these water bodies.”

Jakkur Lake, for instance, attracts hundreds of pelicans every year, with the birds nesting in the lake in August and September.

“If the number of pelican nests are dwindling, one can make a correlation to a disturbance in the environment that the lake offers the birds. It could be that there are other birds which are better adapted to the urban environment are replacing the pelicans. We felt the need for a comprehensive study which also includes diatoms and amphibians to gauge the reasons for possible biological imbalances,” Dr Ramachandra said.

Once known for its pristine wetland systems, Bengaluru has today become a city of shrinking lakes. Encroachment is the major cause for the water bodies vanishing as are cuts in channels that connect them.

“The results of the study will help the government and policymakers to assess the situation in these waterbodies and take up measures to plan for the future,” Dr Ramachandra said.