In Bangalore's lakes
Tests carried out by the Karnataka State Pollution Control Board (KSPCB) after this year's third incident of large-scale fish death in Bangalore's lakes have prompted official agencies to attribute them to sewage ingress. But researchers believe this doesn't explain tonnes of fish dying at one stroke.
Five tonnes of fish died in Puttenhalli Lake in mid-June 2004, two tonnes died in Vengaiahnakere Lake in May 2005 and 3.5 tonnes died in Ulsoor Lake the same month. KSPCB's tests point out that dissolved oxygen content was below average, mainly because of sewage inflow, in all these cases. But R K Somashekar, who heads Bangalore University's Environment Science Department, doesn't agree with the board's hypothesis: "Large-scale sudden fish death cannot happen because of reduced dissolved oxygen content...Though we have not conducted a study, the fish deaths have to be due to some explosive, phenolic compound or pesticide residue."
The Lake Development Authority (LDA) also says that the real reason for the fish deaths in Ulsoor Lake was a tussle between two fishing lease holders. Overpopulation of fish in the lakes could be another reason, as stated in a letter submitted by LDA to the secretary, Department of Environment, Forest and Ecology.
For developing the Vengaiahnakere Lake and Puttenhalli Lake, in 2004-2005, 8,500 fingerlings of three different varieties of fish were stocked in the former.while 1,900 fingerlings were released in the latter.
-- Deepa Kozhisseri
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.