Limnological investigations of water bodies of Dharwad area were started in 1959. Most of these works were concentrated on the physico-chemical factors of the water and their correlations with plankton composition. Fresh water plankters are important component in aquatic ecosystems and participate as a link between the trophic levels. These are more valuable as indicators of trophic conditions and respond more rapidly to the environmental changes than the fishes. Therefore, they are of considerable potential value as water quality indicators. This book is useful for the young researchers as it guides to assess trophic status using zooplankton as indicator. It gives baseline data of some water-bodies of South Indian water-bodies in general and Dharwad area in particular.