In the aquatic environment , the phytoplankton or micro-algae are considered as primary producers of food chain upon which most of marine and freshwater organisms depend on. A phytoplankton bloom has been defined as a "high concentration of phytoplankton in an area, caused by increased reproduction. Blooming can be stimulated by a number of abiotic as well as biotic factor; but nutrient availability of water body seems to be the most limiting factor. Remote sensing is the acquisition of information about an object, without being in physical contact with that object. It makes the using of the electromagnetic spectra to discriminate between objects by using the reflectance, absorbance, and transmittance characteristics in different wavelengths. Aircraft and satellite measurements of spectral reflectance is an effective method for mapping the blooms of algae (spatial distribution) and detecting phytoplankton biomass (pigment composition) and its temporal occurrence. Advances in the manufacturing of highly resolution sensors and data analysis are making the tool of remote sensing attractive and applicable for using in the management and research of coastal and inland waters.