With funding from the Australian Government's 'Saving Native Species Program', Nature Glenelg Trust and Millewa Pumping lead a project titled ‘Sustaining coordinated species-level actions to recover Murray Hardyhead’, aimed at conserving one of Australia’s most critically endangered native freshwater fish, the miraculous Murray hardyhead (Craterocephalus fluviatilis).

Murray hardyhead historically flourished in the southern Murray-Darling Basin wetlands which experienced elevated salinity between flood events (Ellis et al. 2013; Stoessel et al 2019; Whiterod et al. 2019). The species utilises intermittent flooding of the river system for dispersal, re-colonisation, and genetic mixing. Breeding occurs through spring and summer coinciding with historic high seasonal flows and flooding. Sticky eggs are scattered on aquatic plants or submerged structures like logs and inundated terrestrial vegetation throughout the breeding season, where they are sheltered and remain close to warm, well-oxygenated surface water.

The abundance of adults declines at the end of the breeding season, with replacement by the maturing young-of the-year cohort. In good years, individuals that were spawned early in a breeding season can reach maturity in the same season, and breed themselves as late as March. Essentially though, a population is heavily dependent on successful breeding every year. Hence, known populations are often supported by environmental water deliveries timed to maximise breeding habitat and survival of the young fish.

Unfortunately, opportunities for natural dispersal from and between wild populations have diminished due to a reduction in flood frequency linked to river regulation (Mallen-Cooper and Zampatti 2018; Koehn et al. 2020). Ironically, due to there only being a few surviving populations, floods can now have negative impacts. This was highlighted after Murray River flooding in 2023, with the species absent or detected in very low numbers at sites where it had been abundant prior to flooding. (Walker and Ellis 2023).

Our objectives

Recognising the importance of continuity, our project builds on the success of previous conservation and recovery efforts. At its core is the coordination of a National Murray Hardyhead Recovery Working Group, bringing together species experts and state agency representatives from across the fish’s former range. Our project team includes numerous private, government and First Nations entities from NSW, Victoria and South Australia, and is supported by the Murray-Darling Basin Authority, the Commonwealth Environmental Water Office, and the Victorian Environmental Water Holder.  

Our project's key objectives are to:

• monitor the viability of known wild populations,  

• develop back up strategies and contingency populations in case of emergency, and  

• create opportunities for reintroductions into suitable habitats  

Over the past 18 months, our project team has been busily planning and conducting activities to build resilience in known populations and safeguard the species against local extirpations.

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Monitoring

Monitoring teams have been tracking the status of known populations in the Lower Lakes region, South Australian Riverland, western NSW, north-west Victoria, and the Kerang Lakes region. Unfortunately, we haven’t detected the species at four sites (in NSW and South Australia) since flooding in 2024, but we remain hopeful a few individuals survive waiting for salinity to increase and provide a competitive edge.

Contingency populations

Small back up ‘surrogate’ populations have been maintained for several years in three managed waterbodies in NSW, one in Victoria and two in South Australia. In addition to these, new ‘surrogate’ populations were recently established at three Victorian sites.

Wild reintroductions

Murray hardyhead were reintroduced into Brickworks Billabong near Mildura in autumn 2025. Our team is also planning reintroductions into potentially four South Australian riverland wetlands in spring/summer 2025-26. Our team is also planning potential reintroductions into four South Australian riverland wetlands in spring/summer 2025-26. We also aim to return the species to a NSW wetland when increasing salinity eradicates pest Carp. These efforts will source fish from both known wild populations and surrogate sites.

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Project partners:

• Nature Glenelg Trust
• Millewa Pumping Company
• NSW DPI Fisheries
• South Australia Murraylands and Riverland Landscape Board
• North Central Catchment Management Authority
• Mallee Catchment Management Authority
• The Murray-Darling Wetlands Working Group
• The Hazel L Henry - Farmland Nature Refuges
• Nature Foundation S.A
• NSW Department of Climate Change, Energy, the Environment and Water
• Biodiversity Conservation and Science
• Victorian Fisheries Authority

Contributing Traditional Owner groups:

• The First People of the Millewa-Mallee Aboriginal Corporation  
• The Barkandji Native Title Group Aboriginal Corporation
• Barkindji Maraura Elders Environment Team
• Ngarrindjeri Aboriginal Corporation
• The River Murray & Mallee Aboriginal Corporation