The recent death of over a lakh fish in Malathahalli lake has sent shock waves across the city about the quality of fish and the condition of the city’s lakes. But even more shocking are the findings of a recent study.
The study conducted by the department of environmental sciences, Bangalore University reveals that ‘Nualgi’, a biotech product, was sprayed in large quantities to increase fish food to yield more fish from the lake.
There is a growing demand for aquaculture products which has compelled local fishermen to increasingly use chemicals to increase fish growth in lakes. Rama, a fisherman at the lake said, “We were only told to spray this powder to get more fish. We didn’t know the fish would die.’’
According to the reader and principal investigator of the department, Dr N Nandini, a group of young fishermen showed them a used 1 kg packet of biotech food with a brand name ‘Nualgi’. The product was labeled as 100% eco-friendly for use in fresh and sea water with an interesting logo Grow Live Food and Phytoplanktons: We Make Nature and Start the Food Chain.
“The instructions are in English, which the locals do not understand and explain that within three hours, Nualgi will trigger a large population of zooplanktons. So, if you took a kg of Nualgi, 2 kg of urea, 100 gm DAP, 100 gms yeast, all in 100 liters of water and add 50 kg of cow dung and into the lake and waited for 1–2 days, you would finally get the algal bloom and zooplanktons,’’ she said.
Excessive spraying had increased the growth of algae blooms, which led to shortage of oxygen in the lake leading to the death of the fish.
Assistant director of Fisheries, BDA, Shekhar Reddy, said that the fish also died due to sewage water entering the lake. He added that BDA has taken up the task of reviving 12 lakes in the city, and this is one among them. He also added that BDA had written to the principal secretary of environment and forests to ban fishing in this lake.
However, when DNA contacted the principal secretary, Meera Saxena, she denied having received any such letter.
BDA has now requested BWSSB to set up a sewerage treatment plant of 500 mld near the lake to clean the water and divert sewage.
