Original paper

Jahreszeitliche Schwankungen in der Zusammensetzung des Phytoplanktons und Phytobenthos in Altwässern der Lobau bei Wien

[Seasonal fluctuations in the species composition of phytoplancton and phytobenthos in the Lobau near Vienna]

Schwencke-Hofmann, Johanna


During three years physical and biological samples were taken from four different sites out off side arms of the Danube east of Vienna, which are fed either by groundwater or by water from the Danube. The temperature regime differs from that one of deeper lakes. In all seasons homothermic conditions could be observed and sometimes there was also stratification of temperature. There was a total of 541 algae species, 297 of which could be observed in the plankton. All species showed partially different distribution as well as occurrence and frequence. Algae blooms were observed of following species: Stephanodiscus hantzschii, Synura uvella, Peridinium palatinum, Anabaena circinalis, Dinobryon divergens, Chlamydomonas sp. and Asterionella formosa. Depending on the location periphyton algae developed with great frequency on stones and waterplants. The following genera were dominant there: Fragilaria, Cymbella, Rhopalodia, Navicula, Nitzschia and Diatoma. The periphyton on waterplants grew mainly on Myriophyllum and Ceratophyllum. The number of algae of which differed just slightly from each other but were greater on Myriophyllum.