Evolution of physico-chemical quality of the Danube Delta aquatic ecosystem state in the period May-October in 2003-2005

The main objective of this paper is to provide data on the Danube delta quality based on the long-term specific indicators of laboratory analysis results. There were investigated the physicochemical properties of water and sediment samples collected from the Uzlina and Murighiol locations during the period May-October of the consecutive years 2003, 2004 and 2005. The comparative analysis of the quality characteristics of the Danube delta aquatic ecosystem in these three years emphasized a dynamic character of the water quality that can determine an evolution into the unfavorable stages which lead to worsen life conditions for aquatic organisms.