The authors have tried their best to make the text comprehensive and up to date, backed up with field level data, so that the book may serve as a ready source of information to the students who want to pursue their careers in environment related areas. The brain churners added in Chapter 12 is a special feature of the book. Solutions to these questions will strengthen the foundation of students in the verticals of Environmental Science, Ecology, Marine and Estuarine Ecology, Coastal Zone Management, Climate Science, Environmental Biology, Forestry, Fishery Science, etc.