This book attempts to understand the multiple branches that fall under the discipline of marine biology and how such concepts have practical applications. Marine biology refers to the study of marine animals and plants. It classifies them on the basis of environment and examines their structure, composition, interaction with environment and also their importance to humans. Different approaches, evaluations and methodologies and advanced studies on this subject have been included in the book. As this field is emerging at a rapid pace, the contents of this text will help the readers understand the modern concepts and applications of the subject.