The modified ATREM correction, ATREM+,produced an adequate HyspIRI simulation data product for remote sensing reflectance for use in developing and refining water quality and phytoplankton biodiversity algorithms in the coastal zone. The OC3 chl-a algorithm accurately estimated surface cbl-a concentrations for the ship-based radiometry spectra and patchy weakly for the ATREM+spectra for both April and October 2013. The PHYDOTax-derived biodiversity estimates from ship-based radiometry measurements were not statistically significant but did follow the same demographic trends in April as the ground-truth data set derived from CHEMTAX. This was not the case for October 2013. The lack of a trend and statistical significance of the ship-based PHYDOTax estimates warrants further study and refinement of the PHYDOTax algorithm. A more direct cells enumeration instrument like the lmaging Flow Cytobot (Olson & Sosik, 2007; Sosik & Olson, 2007), not available for this study, would have provided a more credible validation data set for PHYDOTax than the error-prone CHEMTAX approach. When comparing PHYDOTax biodiversity estimates derived from image retrievals to the ship-based radiometric estimates, ATREM+had the best fit for both April and October.