Light Harvesting in Unialgal Blooms

Abstract

We developed a model for spectral light absorption coefficients of dinoflagellate cell suspensions based on mean cell dimensions, cellular pigment concentrations, and known pigment-protein absorption spectra. In situ algal absorption coefficients of unialgal dinoflagellate blooms can be discovered by determining pigment concentrations, cell densities, and cell dimensions from water samples. The model can be used to estimate photosynthetic light harvesting and algal contribution to light extinction in the water column. This method is sensitive to photoadaptive responses, and also allows us to assess the relative influences of light quality, accessory pigments, and packaging effects on algal light absorption. Results of the model are presented in the context of a hypothetical dinoflagellate bloom. The model may be extended to estimate primary productivity by adding a photosynthetic efficiency parameter, or including other algal taxa.