State and succession of the ichthyofauna in the antropogenous modified environment of the Srebarna Lake (Danube floodplain, North-East Bulgaria )

Abstract

Alterations of the ichthyofauna in the Srebarna Lake were associated with the information about the environmental parameters. Nowadays the midterm annual dynamics of CPUE reflects the changes inabundance of predominating small-size fishes. The flooding dynamics is a leading factor directly controlling the midterm succession of fish community. The long-term succession of the ichthyofauna is dependent mainly to the “bottom-up” trophic interrelations. Three periods can be distinguished along the long-term succession of theichthyofauna in the Srebarna Lake related to the parameters of flooding dynamics, fishing intensity and trophic conditions.

Keywords

• wetland
• Danube River
• ichthyofauna
• species composition
• community structure
• succession