Oceans play an important role in short and long term changes in weather, bio-geochemical cycle and global carbon cycle/budget. Major ocean features include chlorophyll concentration, current boundaries, sea surface temperature, ocean fronts & eddies, suspended particulate matter and dissolve organic matter. Phytoplankton is responsible for proper functioning of marine ecosystems by providing half of the global primary production, controlling biogeochemical cycle and making up to 90% of earth’s oxygen and foundation of the marine food chain. The book deals with the spatio-temporal variation of phytoplankton along Indian coast. The study is based on 11 years satellite data (1997-2008) which was analyzed by different techniques using ERDAS, ENVI and Arc GIS software. The study shows that there is a large variation of chlorophyll concentration between east and west flowing rivers. The bloom in the western coast can primarily be attributed to favourable bio-physical conditions in comparison to the eastern coast. The study offers insights into the factors responsible for phytoplankton blooms and can be helpful in conservation of phytoplankton and marine ecology.