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Influence of hydraulic conditions over dunes on the distribution of the benthic macroinvertebrates in a large sand bed river
Author(s) -
Amsler Mario L.,
Blettler Martín C. M.,
Ezcurra de Drago Inés
Publication year - 2009
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2008wr007537
Subject(s) - benthic zone , thalweg , geology , beach morphodynamics , sand dune stabilization , hydrology (agriculture) , channel (broadcasting) , geomorphology , ecology , sediment transport , sediment , oceanography , geotechnical engineering , engineering , electrical engineering , biology
This study aims to relate the flow structure over mobile dunes recorded on the channel bed of the Paraná River (Argentina) with the spatial distribution of the benthic macroinvertebrates. The following main conclusions have been obtained: (1) the dunes found in the active channel could be considered as hydraulic biotopes at a mesohabitat scale: the bed forms in the thalweg region are subjected to higher shear stresses with low benthic densities; (2) differences in benthic densities were also recorded at within‐dunes microhabitat scales: the largest densities were found in the dune troughs where small bed shear stresses occur and minimum densities on the low stoss side of dunes where turbulent agitation near the bottom strongly disturb the bed particles; (3) superimposed dunes on larger dunes may be considered as another microhabitat of still smaller dimensions. Summarizing, multiscale approaches are needed if a comprehensive understanding linking hydrodynamics and morphodynamics processes with benthic ecology is intended.