Restoration of a river backwater and its influence on fish assemblage

Abstract

ABSTRACT:The development of fish assemblage in a restored river backwater (Kurfürst backwater, Morava River, Czech Republic) was monitored over a six-year period from its restoration. The structure of fish assemblage remained similar throughout the years. Species richness of adult fish increased from twelve species during the restoration to 20 after it. Initially steady fish abundance (mean 52.3-98.1 inds/ha) and biomass (mean 5.8-7.6 kg/ha) increased significantly in 1999 five years after restoration (576.9 inds/ha and 23.3 kg/ha, respectively). The main resident species were pike Esox lucius, roach Rutilus rutilus, rudd Scardinius erythrophthalmus and perch Perca fluviatilis. High abundance of bleak Alburnus alburnus and chub Leuciscus cephalus was related to their spring spawning period. The structure of the 0+ fish assemblage was similar throughout the years, with chub and bleak prevailing during the restoration, and roach, chub and rudd after it. The number of 0+ species increased from seven to 17. The monitoring documented that the restoration could be considered as beneficial for the fish assemblage. Habitat development of the backwater is likely to influence its current value as a refuge, spawning site and nursery for local fish populations.

The drift of early life stages of Percidae and Gobiidae (Pisces: Teleostei) in a free-flowing section of the Austrian Danube

“…In contrast, the monotypic genus Perca showed comparably low drifting densities, but the perch (P. fluviatilis) is often the most abundant adult percid in the Danube and its backwaters (Schabuss & Reckendorfer, 2002;Loisl et al, 2013). This supports the suggestion of some authors that this species avoids drifting (Reichard et al, 2002b;Zitek et al, 2004b) but may likewise be because of a preference for backwaters, also for reproduction (Schabuss & Reckendorfer, 2002;Hohausova & Jurajda, 2005). At any rate, our results not only show that all percid genera are able to reproduce in the Danube but also illustrate the importance of near-natural shores for spawning and development.…”

Distribution of Common Kingfisher (Alcedo atthis) in the Ramena řeky Moravy National Nature Reserve (Czech Republic) in Relation to the Coppice-with-standard Forest Management

“…A er the year 1989, water quality in the Morava River in Litovelské Pomoraví improved gradually but markedly up to the current state, enabling natural reproduction of the fi sh community (Hohausová & Jurajda, 2005). This process probably had a positive eff ect on the slowly increasing breeding numbers of the Common Kingfi sher in the study area.…”

Restoration Versus Invasive Species: Bigheaded Carps' Use of A Rehabilitated Backwater

“…Increased spring movements into and out of backwater habitats, likely related to spawning, have been observed in other species (e.g. Hohausová and Jurajda, ), and mass spawning movements have been observed in bigheaded carp at other Illinois River backwaters (ACRCC, ) and present the ideal time to collect individuals exiting backwaters or limit access to main channel spawning habitat.…”