An elusive fish

Macquarie perch were once found a broad range of rivers and tributaries of the Murray-Darling basin and parts of south-eastern coastal NSW, including the Hawkesbury-Nepean and Shoalhaven catchments. However, their distribution and numbers have been dwindling with a number of key threatening processes reducing their numbers.  

Removal of riparian vegetation increases erosion and siltation, resulting in the loss of deep pool habitat and smothering cobble bed spawning habitat and eggs, in addition to being outcompeted and predated on by pest species such as Redfin Perch and European Carp.  

Campbelltown Mayor George Brticevic, local federal MP Dr  Mike Freelander, and a volunteer from the first survey in September 2019.

NSW DPI Fisheries

How to identify a Macquarie Perch

The Macquarie Perch are an elongated, oval shaped fish. They are distinguished by large eyes, pores on the snout and around the eye, jaws of equal size, large distinct scales along the body and a rounded tail.

Macquarie Perch from coastal catchments, like the Georges River, are generally blotched with grey-brown, buff and dark grey patches over the head and body.

(Video credit NSW DPI Fisheries)


Express your interest in volunteering are urgently needed to set up and pull in nets, collect data, record fish measurements and review and record habitat conditions. As a volunteer, you will be trained in supporting this process and operational safety. Community volunteers are required to register to be involved.

 Register now

OzFish volunteers taking EDNA samples

What is EDNA?

Environmental DNA leaves tiny traces of evidence in the water where previous sampling efforts have been too difficult to detect. We can find out if a fish lives in the waterway without actually seeing it!

Samples of water are funnelled through a filter in a syringe by volunteers and researchers, or a specialised eDNA filtration backpack. These filters are then taken back to the lab where they are analysed against species ’primers’ which are basically barcodes that tell us if a species is present or not in that sample. While the technology is still being improved, we are at a point now where it can give a very accurate reading.

Very cool science indeed!

Recent results showed isolated platypus populations are present and importantly for fish enthusiasts, the endangered Macquarie perch has also shown up in the tests.

Great! What do you do now with this information?

Data derived from the project will assist Campbelltown City Council and conservation groups like OzFish to further investigate the key issues, threats and locations which are allowing the species to thrive in urban-dominated systems along the Georges River.

These findings will then inform target areas to enhance habitat improvements such as restoration works and revegetation or address other indirect threatening processes to the species such as reduction of water quality through better management of runoff and point source pollution, and reduction of litter and entanglement.

Where to from here?

OzFish is working with Campbelltown City Council to install a number of tangle bins across the river catchment to provide more receptacles for fishers to dispose of discarded line and other tackle. This is aimed at reducing entanglement for native species of fish, birdlife and the platypus which we now know still inhabits this amazing river.

The next steps for OzFish is to get a local OzFish chapter up and running in Southwest Sydney to continue doing this great work, and OzFish are calling on local recreational fishers to get involved. For more information on their continued work to protect and restore fish habitat across Australia, get in touch with on 1800 431 308 or email us at

The project was made possible with support from Campbelltown Council; Macarthur Federal MP Dr Mike Freelander through the Federal Government’s Communities Environment Program, the OzFish Landcare NSW partnership and funding support from the NSW Recreational Fishing Trusts, BCF – Boating, Camping, Fishing and Tate Endowment Fund. 

Thanks to the OzFish Landcare NSW partnership, there are now more much-needed fish habitat projects underway across New South Wales

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