The spatial and temporal dynamics of the physico-chemical characteristics for the quality of aquatic ecosystems of the Danube Delta biosphere

The main objective of the paper is the characterization of the aquatic ecosystems of the Danube Delta based on the temporal and spatial dynamics of the physico-chemical parameters. There were drawn momentary samples from the two stock compartments - water and sediment - from the sampling sites Murighiol and Uzlina in every month in drawing campaigns period (April - September 2003). The results of the analysis for the indicator and chemical parameters determined from Uzlina and Murighiol locations demonstrated the following aspects: - the oxygen regime is not conform with the favourable conditions for the aquatic life development; - high heavy metals (iron, manganese and copper) content in water and sediment; - exceeding concentrations of phenol compounds, mineral oil and Lindan, over the critical limits will have a potential negative impact upon aquatic organisms.