fish communities; Odra river; PLA Poodří; floodplain

The Oder runs through 55.2 km of the Protected Landscape Area Poodří with the area of 81.5 km2. More than 80 % of the length of the river comprises a naturally winding riverbed preserved together with a hydrologic regime and regular floods in the floodplain. Between 1997 and 2001 ichtyological research was carried out in 7 sites on the Oder, i.e. in 3 sites on the main tributaries and 4 in former river arms. The studied river sections are inhabited by Barbus ? Chondrostoma fish community. Leuciscus cephalus, Rutilus rutilus and Barbus barbus are the highest both in the numbers and also in the biomass. The total abundance in individual locations varied between 2.416 ? 20.392 pcs.ha ?1 and the total biomass between 174 ? 788.8 kg.ha-1. In four of the examined small pools there were between 4 and 8 species with low abundance and the biomass and H?= 1.390 ? 1.737

The Oder runs through 55.2 km of the Protected Landscape Area Poodří with the area of 81.5 km2. More than 80 % of the length of the river comprises a naturally winding riverbed preserved together with a hydrologic regime and regular floods in the floodplain. Between 1997 and 2001 ichtyological research was carried out in 7 sites on the Oder, i.e. in 3 sites on the main tributaries and 4 in former river arms. The studied river sections are inhabited by Barbus ? Chondrostoma fish community. Leuciscus cephalus, Rutilus rutilus and Barbus barbus are the highest both in the numbers and also in the biomass. The total abundance in individual locations varied between 2.416 ? 20.392 pcs.ha ?1 and the total biomass between 174 ? 788.8 kg.ha-1. In four of the examined small pools there were between 4 and 8 species with low abundance and the biomass and H?= 1.390 ? 1.737