Mikroskopische und elektronische Zählung von Sestonpartikeln im Wasser der Warnow — ein Vergleich

Abstract

In 37 samples from the river Warnow in the course of one annual variation the seston particles were counted in the inverted microscope in three size classes: A <8 μm, B 8 … 25 μm C>25μm. Parallel to that, counting was performed with the electronic particle counting device Picoscale 4, which is used for the counting of blood cells, in the setting WBC for leucocytes with a nozzle 200 μm in diameter, so that the setting approximately corresponded to the size range B of the microscopic count. The microscopic particle numbers per ml were 800,000 … 5,200,000 for A, 10,000 … 96,000 for B and 2,000 … 21,000 for C. In principle, there is a correlation between microscopic and electronic results for the particles B and C. The regression analysis, however, produces a considerable residual scattering because of the morphological variety of the particles and its changes in the course of the seasonal change of mass. Therefore, the conclusion of the particle density from results of electronic counting is connected with considerable indistinctness, so that the electronic counting can be used only as a supplementary method for the estimation of the density of suspended matter.