Large-scale episodal mortality among the freshwater fishes of certain
lakes of Bangalore City, Karnataka State, India occurred in June 1995.
We conducted an intensive study of the Sankey Lake which is situated in
Sadashiva Nagar of Bangalore city where fish mortality occurred on quite
a large scale during June - July 1995. These studies reveal that the fish-
kill in Sankey Lake was due to a sudden and considerable fall in
dissolved oxygen (DO) levels in some locations caused by sewage let
into the lake resulting in asphyxiation. It was not due to any kind of
infection because none of the fishes appeared to show any symptom of
disease.