A METHOD FOR THE QUANTITATIVE AND QUALITATIVE DETERMINATION OF PLANKTONIC DIATOMS

Abstract

A method for the quantitative and qualitative determination of planktonic diatoms was developed. The method uses the Utermöhl counting technique (in which an inverted microscope is employed) as a basis but also involves the calculation of the relative density of each species in the association (as determined with the ordinary light microscope). A combination of the results thus obtained ensures that even the smallest diatoms (2,5 μm) are accounted for. These often constitute a significant proportion of the population, but are often overlooked or may not even be resolved using Utermöhl's method.