Fish assemblage response to rehabilitation of a sand-slugged lowland river
Version of Record online: 4 FEB 2009
Copyright © 2009 John Wiley & Sons, Ltd.
River Research and Applications
Volume 25, Issue 10, pages 1251–1267, December 2009
How to Cite
Howson, T. J., Robson, B. J. and Mitchell, B. D. (2009), Fish assemblage response to rehabilitation of a sand-slugged lowland river. River Res. Applic., 25: 1251–1267. doi: 10.1002/rra.1226
- Issue online: 12 NOV 2009
- Version of Record online: 4 FEB 2009
- Manuscript Accepted: 6 NOV 2008
- Manuscript Revised: 16 OCT 2008
- Manuscript Received: 12 OCT 2007
- fish habitat;
- restoration ecology;
- large woody debris;
The impact of excessive sediment supply on river channels has been described in many areas of the world. Sediment deposition disturbance alters habitat structure by decreasing channel depth, changing substrate composition and burying woody debris. River rehabilitation is occurring worldwide, but information is scant on fish assemblage responses to rehabilitation in sediment-disturbed lowland rivers. Sediment removal and large woody debris (LWD) replacement were used to experimentally rehabilitate habitat along a 1500 m stretch of the Glenelg River in western Victoria, Australia. Using an asymmetrical before-after control-impact (BACI) design, fish were captured before and after the reach was rehabilitated, from two control reaches and from a ‘higher quality’ reference reach. After two years post-rehabilitation monitoring, the fish assemblage at the rehabilitated reach did not differ from control reaches. Temporal changes in taxa richness and the abundance of Philypnodon grandiceps, Nannoperca spp. and three angling taxa occurred after rehabilitation (winter 2003) compared with the before period (winter 2002), but these effects did not differ between rehabilitated and control locations. Highest taxa richness and abundances occurred at the reference location. High salinity coincided with the timing of rehabilitation works, associated with low river discharges due to drought. The negative effects of other large-scale disturbances may have impaired the effectiveness of reach-scale rehabilitation or the effects of rehabilitation may take longer than two years to develop in a lowland river subjected to multiple environmental disturbances. Copyright © 2009 John Wiley & Sons, Ltd.