Photosynthetic production in the oceans in relation to light, nutrients and mixing processes is discussed. Primary productivity in the estuarine region is reported to be high in comparison to coastal and oceanic waters. Upwelling phenomenon in the west coast of India and Somali region are responsible to keep the productivity high in the Arabian Sea. Sharp peaks of chlorophyll a) observed in Arabian Sea, from satellite imageries could be related to phytoplankton blooms due to upwelling. Turbidity and heavy cloud cover are responsible to keep the productivity values low in the Bay of Bengal. Oceanic regions in the north and south of the equator are marked with lowest values of primary productivity and chlorophyll, and referred as desert regions. High nutrients and ample solar radiation frequently trigger phytoplankton blooms in coastal polynias during Antarctic summer. Energy transfer model for primary productivity has been used to derive potential exploitable fishery resources in the Indian Ocean.