This book provides an insight into the ecological aspects of Gulmarg Wildlife Sanctury. This book mainly focuses on water microbiolgy. Water is essential to sustain life, without it life becomes impossible. Water is an indispensable commodity, which should be easily accessible, adequate in quality, free of contamination, safe, affordable and available throughout the year in order to sustain life. In aquatic system especially those receiving some allochthonous organic input, the secondary production of planktonic bacteria can be co-equal or even larger than that of primary production of phyto-plankton. The number and kind of bacteria found in different types of ecosystem vary and are influenced by the ecosystem processes maintaining plant primary productivity. This Book is a promising tool for students and scholars to understand the ecological and microbiological aspects of lentic and lotic water bodies and to get an idea about the impact of various anthropogenic activities on water quality and ecology of aquatic ecosystem.