3.0 Results and Discussion:
The microphotographs of algae indicating organic
pollution reported by Palmer (1969) are presented
in Plate 1.The index for the genera is shown in
Table 1. The highest organic pollution index is in
Dadadahalli Lake, Karanji Lake, Doddakere Lake
and Dalvoi Lake. The values reach as high as 33.
The least index is observed in Bogadi Lake, while
all other lakes range between a minimum of 20 to
a maximum of 33. Species of Euglena, Oscillatoria,
Scenedesmus and Synedra appear in almost all
lakes and are the most prominent indicators of
organic pollution. The twenty most algal species
tolerant to organic pollution are shown in Table 2.
Euglena acus, Scenedesmus quadricauda and
Synedra ulna are the most tolerant species.
According to the index, a score of 20 or more for a
sample is an indication of organic pollution, while
a score of 15 to 19 is taken as probable evidence
of high organic pollution. Lower values indicate
that the organic pollution is not high. Appling
these values to the present study it is observed
that all the twenty lakes are organically polluted,
since they have a score above 20. The species