CHARACTERIZATION OF PHYTOPLANKTON COMMUNITIES ON THE DANUBE SECTOR KM 169 - KM 197 IN 2021

Marilena Florentina Lăcătuș, Maria Desimira Stroe, G. Ion, Magdalena Tenciu, Mirela Crețu

Abstract
   The objective of this paper was to analyze the phytoplankton communities on the Danube sector km 169 - km 197 in 2021. Phytoplankton samples were performed monthly. For the study of phytoplankton, the water was collected in glass bottles with a volume of 300 ml, from the surface horizon of the water (0 m). After the collection of samples were preserved with Lugol's fixative and sodium acetate (Utermöhl), in the following proportion 0.15 - 0.25 ml solution per 100 ml/sample. Following the study on the characterization of phytoplankton in the studied area, a diversity of variations of phytoplankton communities were found. From the analyzes performed during the research period, we observe the dominance of diatoms, followed by chlorophylls and cyanophytes. Regarding the species found in the analyzed samples, between April and September of 2021, the following conclusions were drawn: in the presence of diatoms (Bacillariophyceae), there are species characteristic of the river such as Synedra acus, Nitzschia palea, and Melosira granulata, which are identifiable each month.