The structure of benthic Diatom assemblages: A preliminary account of the use and evaluation of low-temperature scanning electron microscopy

Abstract

Diatom assemblages on the surface of fine estuarine sediments have, for the first time, been examined undisturbed by a novel application of low-temperature SEM. The technique allows the visualization of surface diatoms and determination of the composition and orientation of the exposed assemblages at any one time. In a laboratory experiment, the total number of diatoms counted was similar to that obtained using the standard lens tissue technique. Although identification was more accurate using the light microscope, many different species could be readily distinguished with low-temperature SEM. An index of similarity analysis suggested a difference in the composition of the assemblages measured by the two techniques. This difference was considered to be due to the selectivity of the lens tissue technique. Further avenues of research in this subject using low-temperature SEM are briefly outlined.