Original paper

Vorläufige Angaben über jahreszeitliche Veränderungen und die vertikale Verteilung des Periphytons im mittleren Abschnitt der Donau

[Preliminary data about the seasonal changes and vertical stratification of periphyton from the middle reach of the River Danube]

Ertl, Milan; Juriš, Štefan; Tomajka, Jozef


The standing crop, chlorophyll a values and species composition of the algae and animals growing on artificial substrates (glass slides with rough surface) in the littoral zone of the river Danube were studied during the course of one year. The artificial substrates were placed at different depths of the littoral zone, which was 6-7 m broad. The growth of the periphyton was limited by the frequent water-level fluctuations and by scouring during the flood. The highest values of the standing crop, as well as the chlorophyll a concentrations, were recorded during the autumn when the water level was relatively constant. The standing crop of algae decreased rapidly with increasing depth, whereas the standing crop of consumers showed a slowly increasing trend. At a depth of about 2.5 m the levelling up of both components was reached.


chlorophyllalgaefloodfluctuationlittoral zoneRiver Danube