Science helps us track how native fish, waterbirds, and plants respond to water for the environment delivery actions. It also helps us track water quality and flow in the River Murray Valley.
Lesson learnt
Monitoring, evaluation and research shows us what's working and what's not. This knowledge helps us manage water for the environment in real-time and in the future.
Connectivity and water quality
Water for the environment plays an important role in flows that connect to floodplains and wetlands and that flow the length of the river, having lots of ecological benefits including:
- flushing carbon and nutrients into the river. This can provide food for bugs, fish and other animals that live in the river
- providing connected passage for fish to move to find habitat and food, and
- exporting large amounts of salt from the Murray Darling Basin. This helps to reduce salinity and improve habitats for fish, plants and frogs.
Monitoring has shown that water for the environment plays an important connectivity role particularly in dry years.
Water for the environmental can also improve water quality helping native fish and other aquatic animals survive. This has been important during and after floods when water quality can be poor. During the 2022-23 flood, water for the environment provided localised areas of good water quality for native fish and other aquatic animals when water quality in the river was poor.
Native fish
Native fish are very responsive to flow and water quality, so we monitor native fish to understand how they respond to different flows in the River. Monitoring has shown that some native fish successfully reproduce in response to flows of certain rates at certain times of year.
For instance, in the lower Murray, monitoring has found that:
- Murray cod generally spawn every year and in 2019 they had a very successful breeding season because the flow conditions were very good in spring 2019. This group of fish that were bred have been detected in large numbers in all later annual fish surveys.
- Golden perch are found to breed more successfully when the water is flowing faster and when its warmer, such as in late spring - summer.
Water quality can also impact native fish. Poor water quality, often related to floods or droughts, can result in fish deaths. It can take many years for native fish populations to recover from these events.
Native vegetation
Meeting the watering needs for native plants is important to maintain and improve their health and extent. The type of plant and where it grows on the floodplain give us an idea of what its watering needs are.
We monitor the health, diversity and extent of plant communities to help us understand how they respond to different flows.
The effects of the 2022-23 flood in the Murray Valley have been widespread with different plant communities responding differently. Trees and shrubs generally improved in health with widespread revival of red gum and black box in parts of the floodplain.
Monitoring has shown that wetting and drying the banks help native plants germinate and grow. The timing and the duration of the wetting and drying is important. Once plants establish on the banks they help to stabilise the bank and provide important habitat.
River Murray Monitoring plan
In 2020–21, we worked with southern Basin states to develop a 5-year monitoring plan for the River Murray with input from experts.
The plan builds on existing monitoring programs and helps to:
- track how the system responds to water for the environment delivery
- assess how native plants and animals respond to flows and where it's needed
- guide and improve water management for the region.
The plan is available at River Murray Channel Monitoring Plan 2021–22 to 2025–26.
River Murray Monitoring evaluation reports can be found on our Mid-Murray science publications.
CEWH science
We support several projects through our CEWH science programs.
In the River Murray Valley, we work on these projects with:
- state departments
- the Murray–Darling Basin Authority
- First Nations people
- scientists
- local community groups and landholders
- industry and irrigation networks.
Flow-MER Program publications
On-ground activities for the Flow-MER Program are underway. Read the Lower Murray and Lower Murray and Coorong, Lower Lakes and Murray Mouth science publications and Mid-Murray River System science publications containing detailed information on the monitoring, evaluation and research activities planned for 2024-2029, including updates and reports. These pages also include reports from other science projects we have funded.
You can also visit the Flow-MER website to learn more about monitoring in the Mid-Murray River System and the Lower Murray Areas.