The long-term goal of this research is to develop the base of knowledge necessary to: (i) understand the magnitudes and variability of the optical properties in the upper ocean; (ii) predict spectral absorption and scattering by seawater as well as underwater light fields and water-leaving radiant fluxes, given the types and concentration of suspended particles. SCIENTIFIC OBJECTIVES My specific objective during the past year was to expand a database of single-particle optical properties for various types of marine microorganisms.