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The importance of inshore areas for adult fish distribution along a free‐flowing section of the Danube, Austria
Author(s) -
Hirzinger V.,
Keckeis H.,
Nemeschkal H. L.,
Schiemer F.
Publication year - 2004
Publication title -
river research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.679
H-Index - 94
eISSN - 1535-1467
pISSN - 1535-1459
DOI - 10.1002/rra.739
Subject(s) - electrofishing , leuciscus , habitat , fishery , abundance (ecology) , sampling (signal processing) , rutilus , geography , fish <actinopterygii> , environmental science , spatial distribution , ecology , biology , remote sensing , filter (signal processing) , computer science , computer vision
This study analyses bank morphological parameters of inshore areas as significant qualifying criteria for the habitat of riverine fish in large rivers. The mesoscaled (1.04±0.35 km) spatial distribution of adult fish was studied along a 50 km stretch of a free‐flowing section of the Austrian Danube. Fish abundance at the inshore zone of the main channel was assessed every month from March 1992 to May 1993, applying stratified random sampling by electrofishing. In order to calculate river morphological variables, a specific DOS application was programmed taking riverbank profiles, slope of the Danube and mean daily water level into account. The sampling sites by environmental variables were analysed by principal component analysis (PCA). PCA scores, together with the relative densities of each fish species in terms of their proportions per catch, were treated by a simple logistic regression. The different species exhibit specific patterns of statistical probability in terms of distribution and densities at distinct structural inshore types with regard to area, slope, habitat heterogeneity and connectivity parameters. Large gradually sloping inshore areas are characterized by rheophilic Chondrostoma nasus , Leuciscus idus and Abramis ballerus , whereas eurytopic species do not show a consistent pattern. Heterogeneous stretches contain high proportions of Leuciscus cephalus , Abramis brama and Abramis ballerus . Connectivity discriminates strictly riverine species like Chondrostoma nasus from rheophilic species which require non‐channel habitat during their life history. Copyright © 2003 John Wiley & Sons, Ltd.