APPLICATIONS OF MICROPHOTOMETRY TO OPTICAL OCEANOGRAPHY
R. Iturriaga
Department of Biological Sciences
University of Southern California
Los Angeles, California - U.S.A.
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.
INTRODUCTION
A thorough characterization of the optical properties of the particulate suspended matter is
essential to understanding the spectral absorption of submarine light and its sources of
variability. A common approach used to determine the spectral absorption of marine
particulates has been the concentration of samples on filters. However, these determinations
only provide the absorption of the bulk particulates indiscriminately, making it difficult to
interpret such measurements in terms of taxonomy, physiological adaptation of species, or
relative contribution to light attenuation by specific categories.
A microphotometric procedure to directly measure the spectral absorption and fluorescence
properties of phytoplankton cells and detrital matter has proved valuable for determining
NATO ASI Series, Vol. G 27
Particle Analysis in Oceanography
Edited by S. Demers
© Springer·Verlag Berlin Heidelberg 1991
R. Iturriaga
Department of Biological Sciences
University of Southern California
Los Angeles, California - U.S.A.
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.
INTRODUCTION
A thorough characterization of the optical properties of the particulate suspended matter is
essential to understanding the spectral absorption of submarine light and its sources of
variability. A common approach used to determine the spectral absorption of marine
particulates has been the concentration of samples on filters. However, these determinations
only provide the absorption of the bulk particulates indiscriminately, making it difficult to
interpret such measurements in terms of taxonomy, physiological adaptation of species, or
relative contribution to light attenuation by specific categories.
A microphotometric procedure to directly measure the spectral absorption and fluorescence
properties of phytoplankton cells and detrital matter has proved valuable for determining
NATO ASI Series, Vol. G 27
Particle Analysis in Oceanography
Edited by S. Demers
© Springer·Verlag Berlin Heidelberg 1991