Hyper spectral optical discrimination of phytoplankton community structure in coastal waters, south eastern Arabian sea

Abstract

The ability of hyper spectral optical measurements to discriminate changes in the composition of phytoplankton communities in coastal waters is well studied. The performance of spectral fourth derivative analysis and clustering techniques to differentiate four different algal blooms is done. Phytoplankton absorption coefficient , aph, and remote-sensing reflectance, Rrs are used in the analysis. Samples were collected on monthly basis from coastal waters off Kochi. Similarity index was applied to measured spectra of aph and Rrs. Similarities between abundance-based and optically-based classifications were better for the optical data of Rrs than aph. This analysis showed that, hyperspectral Rrs can be used as a potentially suitable input data for the differentiation of phytoplankton taxonomic groups. These results suggest using of hyperspectral optical data of aph and Rrs with derivative spectroscopy as a promising approach to identify bloom forming phytoplankton in coastal waters.