INDIVIDUAL AND BULK ANALYSIS OF THE OPTICAL PROPERTIES OF MARINE
PARTICULATES: EXAMPLES OF MERGING THESE TWO SCALES OF ANALYSIS·
R. Iturriaga 2 , A. Morel 3 , C. Roeslet and D. Stramski 2
2Department of Biological Sciences
University of Southern California
Los Angeles, California
USA
3Laboratoire de Physique et Chime Marine
B.P.806230
Villefranche-sur-Mer
France
40ceanography WB-IO
University of Washington
Seattle, W A 91895
USA
In recent years cytofluorometric and microphotometric techniques have significantly
contributed to the field of biological and optical oceanography. Such determinations have
enabled us to better understand the composition of some natural phytoplankton communities.
We can now discriminate between Synechococcus clone types in the ocean, sort and analyze
minute prochlorophytes, follow microalgae cell cycles, and determine the spectral absorption
properties of individual cells as well as detrital particulates of field samples. Analysis at the
individual level constitutes another valuable tool for the study of phytoplankton cells and
detrital particulates in aquatic systems.
Until recently most absorption, scattering and fluorescence determinations were performed on
bulk measurements. When dealing with algal populations or other microorganisms grown in
culture, such bulk measurements can be interpreted in terms of optical properties at the level
of a single cell, i.e. efficiency factors for absorption or scattering which represent a "mean"
cell of the population (Morel and Bricaud, 1986). This requires that cell abundance and size
'Comments from the open session on the optical properties of marine particles
NATO AS! Series, Vol. G 27
Particle Analysis in Oceanography
Edited by S. Demers
© Springer-Verlag Berlin Heidelberg 1991
PARTICULATES: EXAMPLES OF MERGING THESE TWO SCALES OF ANALYSIS·
R. Iturriaga 2 , A. Morel 3 , C. Roeslet and D. Stramski 2
2Department of Biological Sciences
University of Southern California
Los Angeles, California
USA
3Laboratoire de Physique et Chime Marine
B.P.806230
Villefranche-sur-Mer
France
40ceanography WB-IO
University of Washington
Seattle, W A 91895
USA
In recent years cytofluorometric and microphotometric techniques have significantly
contributed to the field of biological and optical oceanography. Such determinations have
enabled us to better understand the composition of some natural phytoplankton communities.
We can now discriminate between Synechococcus clone types in the ocean, sort and analyze
minute prochlorophytes, follow microalgae cell cycles, and determine the spectral absorption
properties of individual cells as well as detrital particulates of field samples. Analysis at the
individual level constitutes another valuable tool for the study of phytoplankton cells and
detrital particulates in aquatic systems.
Until recently most absorption, scattering and fluorescence determinations were performed on
bulk measurements. When dealing with algal populations or other microorganisms grown in
culture, such bulk measurements can be interpreted in terms of optical properties at the level
of a single cell, i.e. efficiency factors for absorption or scattering which represent a "mean"
cell of the population (Morel and Bricaud, 1986). This requires that cell abundance and size
'Comments from the open session on the optical properties of marine particles
NATO AS! Series, Vol. G 27
Particle Analysis in Oceanography
Edited by S. Demers
© Springer-Verlag Berlin Heidelberg 1991