The first annual Macquarie River and Marshes fish sampling survey under the Flow-MER program was undertaken at 20 sites between Burrendong Dam and the Macquarie-Barwon River confluence in February and March 2025.

Conducted by the New South Wales Department of Primary Industries and Regional Development (NSW DPIRD) on behalf of the University of New South Wales (UNSW), 14 fish species were captured, including 10 native fish species and four introduced species.

The composition and abundance of species across the 20 sites were varied.

The sampling indicated there was breeding of Murray cod during Spring and Summer 2024 – the last breeding season – in the Macquarie River between Narromine and Gin Gin.  Murray cod abundance in the river downstream of the town of Warren was relatively low.

Similarly, golden perch abundance was greater upstream of the Macquarie Marshes. These were mature fish, primarily around 380mm long.

There was minimal recruitment of common carp, with minimal young-of-year found, indicating low levels of breeding over spring/summer.

The findings will be compared with past and future survey results to understand changes in native fish population structure, abundance, diversity, recruitment and condition, to determine how environmental water benefits native fish.

A few of the fish sampled during the survey included (clockwise from top left) a fingerling Murray cod, an adult Murray cod and a Murray-Darling rainbowfish (Photos: NSW DPIRD)