In May 2025, the first annual Lower Balonne fish sampling was undertaken across 20 sites on the Balonne, Birrie, Bokhara, Culgoa and Narran rivers.

Over 1500 fish were captured, with the bony bream (Nematalosa erebi) being the most abundant native species and the European carp (Cyprinus carpio) the most abundant introduced species.

Conducted by Austral Research and Consulting on behalf of the University of New South Wales (UNSW), 112 golden perch (Macquaria ambigua) – a mix of young-of-year and mature fish (50-400mm) – were captured across most sites.

Only a single silver perch (Bidyanus bidyanus) was encountered. Further analysis is required to determine if it is a stocked or wild-grown fish.

Hyrtl’s catfish (Neosilurus hyrtlii) were also captured at two sites in the Narran River.

These findings will be compared with future survey results to understand how native fish population structure, abundance, diversity, recruitment and condition change in relation to water flows, including use on environmental water.

The NSW and federally listed Murray cod (Maccullochella peelii). Balonne River, St George (Image: Austral Consulting).