One of the major challenges of ocean color research is distinguishing phytoplankton groups from in situ, airborne and satellite measurements to better understand diversity of phytoplankton and some involved biochemical processes. In this framework, high spectral resolution measurements of the remote-sensing reflectance, hyperspectral Rrs(λ), can potentially yield more information about the presence of diverse phytoplankton groups than can be gleaned from traditional analyses of single band-ratios at discrete wavelengths (i.e. multispectral approaches). We introduce and discuss the feasibility of performing derivative spectroscopy and cluster analysis of hyperspectral Rrs(λ) to improve the automatic identification of phytoplankton populations in open ocean waters.