Since the 2010-12 flood events, scientists have:
- Studied the migration and habitat association of icon species Murray Cod;
- Investigated spawning triggers of golden perch (callop) and silver perch and the subsequent recruitment process;
- Identified the changes in fish habitat and assemblage structure in the main channel due to variations in river flows; and
- Evaluated the response of wetland fish communities including the invasive common carp populations.
The research – all part of the A$1.5 million Murray Flood Ecology project – will provide further scientific information to conserve and support the riverine fish communities, particularly during extended drought.
The Minister for Agriculture, Food and Fisheries Gail Gago said the research presented important data for long-term sustainable solutions for lower River Murray ecosystems.
“The Murray Flood Ecology project, commissioned by the State-funded Goyder Institute for Water Research in 2010, studied all aspects of the ecosystem – from fish to plants to water quality,” she said.
“The findings, which combine all elements of the landscape, will help authorities to balance the needs of the community, irrigators, landowners and the environment.
“Management of the Murray-Darling Basin Plan brings together a range of partnerships and decision-making which relies on science and research to yield the best results with available resources.”
Project leader, Dr Qifeng Ye from the State Government’s research institute SARDI, said the break of the millennium drought in 2010 was an opportunity to examine ecosystem responses in the main channel and associated floodplain and wetlands.
“The flood event of 2010-11 was a rare opportunity to capture the responses of the lower River Murray ecosystems to over-bank flows,” Dr Ye said.
“Since 2011, we have seen an increase in large-bodied fish populations such as Golden Perch and some Murray Cod recruited during the 2010 flood have started to be detected after two years. However, there has also been an increase in carp which is a flood opportunistic invasive species.
“River restoration and environmental water management require a multi-year commitment and a system-based approach to managing the 2000 km of river, taking into account the lateral and longitudinal connectivity of flows.
“Environmental flows could be managed in innovative ways to mimic natural flow regimes in order to restore ecologically important hydrological and hydraulic characteristics for rehabilitation of the ecosystems in the heavily regulated system.”
The Murray Flood Ecology Project involved 38 researchers from Goyder Institute partners, SARDI (the research division of Primary Industries and Regions South Australia), Flinders University, University of Adelaide, CSIRO’s Water for a Healthy Country Flagship, and the South Australian Murray-Darling Basin Natural Resources Management Board.
Goyder Institute Director Dr Michele Akeroyd said the information gained from the project will help government and other agencies to develop policy and management strategies to adapt to a water scarce environment.
“It will contribute essential data for developing improved ecological response models to inform river operation and environmental flow management in the lower River Murray to optimise ecological outcomes,” Dr Ackeroyd said.