Most of the existing satellite sensors lack the spectral capabilities to discriminate phytoplankton pigments in water bodies. New satellite sensors (i.e. SeaWIFS) and future sensors on board EOS withnarrow bandwidths will provide fine spectral resolution necessary to distinguish optical properties of nearshore waters provided sea data are available. This will enable spaceborne water color sensors to discriminate bloom forming phytoplankton species. The objective was to develop a library of absorption spectra for the most common phytoplankton species found within the Hudson/Raritan Estuary and coastal waters of New Jersey. Both culture-grown and field samples of phytoplankton were concentrated and analyzedusing chemical and spectrometric techniques. Using spectral derivative and polynomial regression analysis, it was possible to identify wavelengths that could be used to characterize the pigment compositions of phytoplankton species in the estuary.