Present book will increase the understanding of different microbial populations of Dal lake with special focus on recovery of Salmonella spp. and Escherichia coli from water and fish (Schizothorax niger) samples. The book will throw light on the correlation of physico-chemical parameters with the occurrence of different strains of microbes in aquatic ecosystem. The book will teach the use of alterations in water chemistry as tools for assessing the level of bacterial contamination.