Synopsis The present book has been written on the facts studies, to reflect various aspects of different microbial ecology of river Ganga at Hardwar. The coverage also includes description of the abiotic and microbial parameters of water. The seasonal fluctuations of various physico-chemical parameters have been discussed in relation to different type of bacteria observed at this place. Besides these the authors has also reported the zooplankton and phytoplankton of the river Ganga and its relation with abiotic factors. The book should form a very useful contribution for Limnologists, Biologists, Microbiologists and post graduate studies all courses in microbial ecology and limnology.