Fish communities in the Poodří Protected Landscape Area (the Odra River basin)

Abstract

The Odra River, 55.2 km of its length, is winding through the Poodří Protected Landscape Area, which has total area of 81.5 km2. More than 80% of its stream has retained the natural character of its riverbed and the hydrological regime with regular floods. Ichthyologic research was carried out in the period 1997-2001. It took place in 7 localities comprising 3 localities situated in main tributaries and 4 localities of former river arms. Gill nets and electrofishing were used for the research on limnetic biotopes. A total of 22 fish species in the streams (Odra, Lubina, Ondřejnice, and Bílovka Rivers) and 4 other species in stagnant water bodies were found. Out of all identified species, Oncorhynchus mykiss, Pseudorasbora parva, and Carassius auratus are not native species. Anglers identified further 7 species in their catches. The studied river sections are inhabited by the Barbus - Chondrostoma fish community. The highest biomass belongs to the most frequent species Leuciscus cephalus, Rutilus rutilus, and Barbus barbus. Total abundance in the individual localities ranged from 2 416 to 20 392 fishes/ha and total biomass was in the range from 174 to 788.8 kg/ha. The species diversity index H′ of ichthyocenoses fluctuated between 2.238 to 3.108 in the area. There were 4-8 species in low numbers in 4 searched pools. The biomass was also low and the diversity index H′ ranged from 1.390 to 1.737.