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Effects of flow regulation on carp ( Cyprinus carpio L.) recruitment in the Murray–Darling Basin, Australia
Author(s) -
Driver P. D.,
Harris J. H.,
Closs G. P.,
Koen T. B.
Publication year - 2005
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.850
Subject(s) - carp , cyprinus , altitude (triangle) , juvenile , structural basin , biomass (ecology) , common carp , fishery , cyprinidae , environmental science , biology , ecology , hydrology (agriculture) , fish <actinopterygii> , geology , geotechnical engineering , paleontology , geometry , mathematics
Carp biomass density and the numbers of ‘sub‐adult’ (juvenile, plus young‐of‐the‐year) carp were used to indicate net recruitment (hereafter ‘recruitment’) to carp populations in ‘regulated’ and ‘unregulated’ lowland rivers (< 300 m altitude) and ‘slope’ rivers (300–700 m) of the Murray–Darling Basin, southeastern Australia. Most recruitment occurred at lower‐altitude reaches, during October–March (water temperature 95% confidence limits=16–32°C). Temporal changes in distribution of juvenile carp and sub‐adult carp, and high biomass density and slightly larger carp sizes in slope populations, indicated that slope sites were ‘sinks’ for downstream ‘source’ populations. The distribution of sub‐adult carp also suggested that recruitment differed between regulated and unregulated lowland sites, and unregulated sites had proportionately more sub‐adult carp in the total catch. We suggest that while floods might have enhanced recruitment in unregulated rivers, flow regulation provides long‐term refuge from mortality associated with high flows. Copyright © 2005 John Wiley & Sons, Ltd.