Zooplankton dynamics in response to the transition from drought to flooding in four Murray–Darling Basin rivers affected by differing levels of flow regulation
- 600 Downloads
Extreme low and high flow periods associated with droughts and floods regularly influence many river systems, yet little is known regarding their role in shaping riverine zooplankton communities. This study investigated zooplankton dynamics in response to the transition from drought to flooding in four southern Murray–Darling Basin rivers managed by different levels of flow regulation. Results indicated that the onset of flooding was associated with an increase in the taxon richness and total transport (abundance) of zooplankton in the unregulated Ovens and Kiewa Rivers, and an increase in the total transport of zooplankton in the mildly regulated Broken River. In comparison, no significant flood effects on zooplankton taxon richness or transport were detected in the highly regulated Murray River. This suggests that the flooding was beneficial for enhancing zooplankton abundance in the Ovens, Kiewa and Broken Rivers, whereas any potential benefits were comparatively short-term and/or reduced in the Murray River. We hypothesise that the relatively short-term and/or reduced response of the zooplankton community to the flooding in the Murray River was probably largely due to the occurrence of a hypoxic blackwater event in suppressing zooplankton emergence.
KeywordsAustralia Disturbance Hydrology Productivity Regulated river
We gratefully acknowledge Professor Marti Anderson for providing advice regarding statistical analysis. We also thank all of The MDFRC staff who assisted with field work and sample processing, particularly Helen Gigney, Rochelle Petrie, John Pengelly, Simon Maffei, Jonathon Thompson, and Karla Williams. This study was funded by the Department of Sustainability, Environment, Water, Populations and Communities and the Murray–Darling Basin Authority.
- American Public Health Association, 1998. Standard Methods for the Examination of Water and Wastewater, 20th ed. American Public Health Association, Washington, DC.Google Scholar
- Anderson, M. J., R. N. Gorley & K. R. Clarke, 2008. Permanova+ for Primer: Guide to Software and Statistical Methods. National Environment Research Council, Plymouth.Google Scholar
- Clarke, K. & R. M. Warwick, 2001. Change in Marine Communities: An Approach to Statistical Analysis and Interpretation, 2nd ed. National Environment Research Council, Plymouth.Google Scholar
- Cottingham, P., M. J. Stewardson, J. Roberts, L. Metzeling, P. Humphries, T. Hillman & G. Hannan, 2001. Report of the Broken Scientific Panel on the Environmental Condition and Flows of the Broken River and Broken Creek. Co-operative Research Centre for Freshwater Ecology, Department of Natural Resources and Environment, Victoria.Google Scholar
- Crabb, P., 1997. Murray-Darling Basin Resources. The Murray-Darling Basin Commission, Canberra, Australia.Google Scholar
- CSIRO, 2011. The Millennium Drought and 2010/2011 Floods. South Eastern Australian Climate Initiative (SEACI), Canberra, Australia.Google Scholar
- International Standards Organisation, 1994. Water Quality—Measurement of Biochemical Parameters, Spectrophotometric Determination of the Chlorophyll-a Concentration (ISO 10260: 1992(E)) ISO Standards Compendium, Environment—Water Quality, Volume 2—Chemical Methods, 1st edn. International Standards Organisation, France: 308.Google Scholar
- Junk, W. J., P. B. Bayley & R. E. Sparks, 1989. The flood pulse concept in river-floodplain systems. Proceedings of the International Large River Symposium, Canadian Special Publication of Fisheries and Aquatic Sciences 106:110–127.Google Scholar
- King, A. J., 2002. Recruitment ecology of fish in floodplain rivers of the southern Murray Darling Basin, Australia. PhD thesis, Monash University, Melbourne, Australia.Google Scholar
- Marsh, N. A., M. J. Stewardson & M. J. Kennard, 2003. River Analysis Package. Co-operative Research Centre for Catchment Hydrology, Monash University, Melbourne, Australia [available on internet at http://www.toolkit.net.au].
- Ning, N. S. P., D. L. Nielsen, T. J. Hillman & P. J. Suter, 2010b. Microinvertebrate dynamics in riverine slackwater and mid-channel habitats in relation to physico-chemical parameters and food availability. River Research and Applications 26: 279–296.Google Scholar
- Rowe, K., 1972. A Study of the Land in the Catchment of the Kiewa River. Soil Conservation Authority, Melbourne, Australia.Google Scholar
- Shiel, R. J., 1995. A Guide to Identification of Rotifers, Cladocerans and Copepods from Australian Inland Waters. Cooperative Research Centre for Freshwater Ecology. Canberra, Australia.Google Scholar
- Twombly, S. & W. M. Lewis Jr., 1987. Zooplankton abundance and species composition in Laguna La Orsinera, a Venezuelan floodplain lake. Archiv für Hydrobiologie Supplement 79: 87–107.Google Scholar
- Vranovský, M., 1995. The effects of current velocity upon the biomass of zooplankton in the River Danube side arms. Biologia 50: 461–464.Google Scholar