Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis (Jan 2012)

The influence of changes to abiotic parameters on the fish assemblage structure of a lowland stream

  • Tomáš Vítek,
  • R. Kopp,
  • J. Mareš,
  • T. Brabec,
  • P. Spurný

DOI
https://doi.org/10.11118/actaun201260030207
Journal volume & issue
Vol. 60, no. 3
pp. 207 – 216

Abstract

Read online

Ichthyological monitoring and the assessment of 16 physical and chemical parameters of the water environment were conducted at two localities on the Dyje River, Czech Republic, at different distances downstream from the Znojmo Reservoir (at 12 and 31 km) to reveal habitat alterations. Canonical correspondence analysis confirmed that differences in fish abundance between localities were influenced by different hydrological regimes characterized by discharge and flow velocities and also by water conductivity, which increased with the distance from the reservoir. The influence of chemical parameters of water related to water quality on fish assemblage structure was insignificant. The second locality (further from the reservoir) was characterised by substantial water shortage during the vegetation season. Changes in hydrological regime and the loss of connectivity in the Dyje River both connected with dam building and water shortage for irrigation have led to dramatic changes in the fish assemblage structure since the 1950s and the complete loss of common nase.

Keywords