Applications of Microphotometry to Optical Oceanography

Abstract

The study of individual particulates through microphotometry provides an accurate measurement of the specific contribution of phytoplankton and detrital particles to the spectral absorption of submarine light. Thus, a link between individual particles and bulk particulate can be analyzed and integrated with physical and biological data. Such information provides the basis for developing appropriate and linked models of variability from individual particles to mesoscale particulate suspended matter in the ocean.

Results obtained using the present methodology are quantifiable and are consistent with standard macrophotometric methods. Microphotometry has been successfully applied to natural samples of marine particulates, enabling taxonomic, geometrical and optical data to be collected simultaneously. In addition, the determination of the absorption and fluorescence of individual phytoplankton cells has been valuable in characterizing individual phytoplankton cells by their excitation spectra, in determining their photoadaptive levels, and in assessing their intrasample variations.

Other applications of microphotometric analysis to marine optics and cell biology of phytoplankton cells are being investigated with a highly sensitive video image system interfaced to the photomicroscope system. We hope image processing will facilitate the quantification of morphological and optical properties of the particulate suspended matter. This will enable us to assess the contributions that different particle types and sizes make to particulate absorption of submarine light in aquatic environments.