STRUCTURAL CHANGES OF BACTERIAL COMMUNITY IN DELTAIC ECOSYSTEMS

Elena Stanescu (Voinea), Catalina Stoica, Irina Lucaciu, Alina Catrangiu, Margareta Nicolau, Stefania Gheorghe, National Research and Development Institute for Industrial Ecology – ECOIND, Romania

Abstract

The aquatic ecosystems are dynamic systems that keep their stability in the conditions of permanent fluctuations of biotic and non-biotic parameters. The dynamic equilibrium of the aquatic ecosystems is acomplished because of the conexions between the species and the environmental conditions and also because of the  mutual conexions between the existing populations.
The purpose of the present paper is to highlight the structural dynamics on short-term for bacterioplankton and bacteriobenthos in storage and cycling compartments from the deltaic aquatic ecosystems.
The dynamics of these biotic components is influenced, on one hand, by qualitative and quantitative structure of primary producers and their life cycles, and, on the other hand by allochthonous inputs of organic matter.
The changes in trophic structure may be associated with significant effects on the rate and quality of main ecological processes that provide services and resources.
The obtained results are presented in a centralized manner for each location studied in comparison with the limits imposed by the Norm concerning the reference objectives for the surface water quality classification  - Order no 161 from 2006, order transposed in 2000/60/EC Water Framework Directive.

Keywords: deltaic ecosystems, bacterial community, water and sediment quality