Environmental outcomes

The ecological health of the Basin’s rivers and other water systems is central to a healthy, working Basin now and into the future.

Key knowledge gaps have emerged in our understanding of Basin management to sustain the health of ecosystems. Better understanding of the factors maintaining ecological resilience during low water flow periods is critically important to inform water planning and management.

First Nations peoples’ traditional knowledge of river systems is an essential source of knowledge which, alongside western science, will help identify risk factors for low water flow periods to help planners and policy makers.

Research questions

• Research Question 9. What are the low flow needs of the environment?
• Research Question 10. How can we best prioritise water-dependent ecosystems for management to ensure representative populations and communities of native biota are protected and restored?
• Research Question 11. How can we predict the health of aquatic ecosystems and their response to changes in flow?

Projects in this theme

Three projects are being undertaken to answer Research Question 9.

• Drivers of ecological resilience and persistence during low and cease-to-flow conditions in the northern Murray–Darling Basin is investigating the ecological, hydrological, physical and water quality drivers of ecological condition in waterholes under low flow and cease-to-flow periods.
• Forecasting risks to fish and their available habitat from low flows and hypoxia is developing a predictive model to assess risks to species and their critical habitats during low flow, cease-to-flow and/or high flow events in the Barwon–Darling River.
• Maintaining Barkandji fish traps and their cultural values is helping to gain recognition of Indigenous cultural, social and economic rights to and an equitable share in clean, accessible water and healthy rivers. The project will demonstrate how fish traps are an important part of Barkandji culture and the river ecology.

Two projects are being undertaken to answer Research Question 10.

• A data atlas for conservation prioritisation is developing spatially-explicit biophysical and socio-economic datasets and integrating assembled data layers within a spatial geodatabase for mapping and conservation prioritisation analyses.
• Evaluating protection gaps and conservation prioritisation is assisting to identify places of high conservation value and to prioritise management actions to conserve the critical assets, values and functions in these areas.

Four projects are being undertaken to answer Research Question 11.

• Spatially explicit population models for fish in the Barwon–Darling river system is building upon existing population models to predict the responses of fish in the Barwon Darling to forecasted changes to climate and hydrology. These models can predict the population-level outcomes of increasing frequency and duration of low flows and cease-to-flows, including the likelihood and consequences of fish kills under future scenarios of climate and hydrology.
• Predicting changes to the persistence and connectivity of in-channel aquatic habitat in the Lower Darling River (Baaka) is mapping the presence of persistent surface water and its connectivity through time. These data are critical to understanding dispersal opportunities for fish and identifying when aquatic habitats may be at risk of declining water quality, due to prolonged cease to flow events.
• Predicting change in floodplain habitat availability at the Basin scale is developing a spatial time series of inundation, coupled with statistical models, to identify floodplain aquatic habitats that become inundated under different antecedent flow and rainfall conditions. The statistical models can generate scenario evaluations of future floodplain aquatic habitat extent under varying climate change and water use scenarios.
• Assessing future vulnerability of species and ecological communities is combining information on the distributions, habitat requirements and vulnerabilities of key fish and vegetation species and ecological communities, with climatic, environmental, and hydrological analyses. This work provides predictions on how species are likely to respond to the impacts of warming climates and less frequent floodplain inundation, which informs prioritisation of options for water management and complementary works (e.g. refuge restoration/creation).

Why this work is important

Increasing water scarcity will require prioritisation of environmental assets and values for targeted management to sustain and restore their conservation values. There is a significant need to include First Nations peoples’ perspectives on what is valuable and where priorities should be. Improved predictive capability using models and tools will also allow research end-users to understand the spatial distribution of environmental assets and values, how they respond over time to water management, and the risks to future species population and ecosystem sustainability.

Key outputs and outcomes for the environmental outcomes theme

Improved understanding of low flow requirements of the Basin’s environmental assets and values to inform water planning and management, particularly under a changing climate.

Prioritisation of environmental assets, values and functions for targeted water management and complementary measures to sustain and restore their conservation values.

Development of predictive models to better understand the spatial distribution of environmental assets and values, how they respond over time to water management, and the risks to future population and ecosystem sustainability from ecosystem stress.

Any enquiries can be sent to MDWERP@mdba.gov.au.