HYDROBIOLOGICKÁ STUDIE STŘEDNÍHO TOKU BEČVY

Abstract

The present work gives the results of the hydrobiological research of the middle course of the Bečva River in the river section between Valašské Meziříčí and Přerov, carried out in the years 2004 to 2007. Altogether, 65 taxa of macrozoobenthos were determined in the period 2000-2007 in the middle course of the Bečva River : Coelenterata (1 taxon), Oligochaeta (5 taxa), Hirudinea (3 taxa), Gastropoda (4 taxa), Isopoda (1 taxon), Amphipoda (2 taxa), Hydracarina (1? taxon), Ephemeroptera (7 taxa), Plecoptera (1 taxon), Odonata (3 taxa), Heteroptera (1 taxon), Megaloptera (1 taxon), Trichoptera (9 taxa), Coleoptera (3 taxa), Diptera (23 taxa). The number of zoobenthos taxa fell in the period 2004–2007 in comparison to period 2000–2002 from 51 taxa to 40 taxa. The decline of zoobenthos taxa was registered on study localities, as follows : Choryně (from 28 to 23 taxa), Hustopeče (from 27 to 25 taxa), Rybáře (from 35 to 28 taxa), Grymov (from 31 to 25 taxa). Average saprobity index of benthic community of the middle course of the Bečva River was 2.35. Average saprobity indices of monitored localities towards downstream were as follows: Choryně 2.41; Hustopeče 2.25; Rybáře 2.40; Grymov 2.34.